Interactions of Humans & the Environment

published in: 2023 - 2022 - 2021 - 2020 - 2019 - 2018 - 2017 - 2016

2024

Realistic microplastics harness bacterial presence

Missawi O, Wouters C, Lambert J, Garigliany M-M, Kestemont P, Cornet V. 2024. Realistic microplastics harness bacterial presence and promote impairments in early zebrafish embryos: Behavioral, developmental, and transcriptomic approaches. Chemosphere 350:141107. DOI: 10.1016/j.chemosphere.2023.141107.

The plastisphere is a newly recognized ecosystem. However, its interaction with early life stages of aquatic vertebrates is a multifaceted issue that requires further research. This study investigated the involvement of bacteria in shaping realistic microplastics hazards in zebrafish Danio rerio embryos. Fish were exposed to bottle micro-fragments (FR) and textile micro-fibers (FI) of polyethylene terephthalate (5–15 μm), concomitant with Aeromonas salmonicida achromogenes challenge from 2h post-fertilization for 3 days. Egg chorion showed affinity for FR and FI, inducing earlier embryo hatching. However, this effect was masked by biofilm invasion. Fragments were more detrimental than fibers on developmental parameters, while bacterial presence compromised body length, eye, and yolk sac surface area. In a further finding, MPs alone increased locomotor activity in zebrafish larvae, without synergistic effect when combined with bacteria. Data showed that realistic MPs had no significant effects except for downregulated sod and cyp1a gene expression, whereas bacterial challenge inhibited larval potency for most of the evaluated mRNA levels (mpx (immune system), apoeb (lipid metabolism), nfkb and tfa (inflammation), cyp and sod (oxidative stress)). This study provides new insights into realistic microplastic effects under relevant conditions when combined with environmental pathogen within the first life stages of aquatic vertebrates.

Local deities and traditional beliefs in mangroves

Gnansounou SC, Salako KV, Visée C, Dahdouh-Guebas F, Glèlè Kakaï R, Kestemont P, Henry S. 2024. The role of local deities and traditional beliefs in promoting the sustainable use of mangrove ecosystems. Forest Policy and Economics 160:103145. DOI: 10.1016/j.forpol.2023.103145.

Customary laws and traditional beliefs are progressively used in conservation and management of natural resources. However, their effectiveness has received limited attention. This case study from the Benin Republic (West Africa) examines how local deities and traditional beliefs can reduce manmade threats to mangroves. Data were collected from three categories of mangroves (sanctuary, sacralised, and non-deity mangroves) via direct observations, informal interviews, in-depth interviews, focus group discussions and household surveys. We used twelve indicators including the quantity of resources collected, the use value and the perceived diversity of fish and plant species to characterize each category of mangroves. Eight of these twelve indicators showed significant variation among the categories of mangroves. Highly destructive uses were generally associated with non-deity mangroves, whereas moderately and less destructive uses were mostly associated with sacralised and sanctuary mangroves, respectively. Local deities can thus assist to limit unsustainable use of mangrove forests. Among the mangrove users, salt producers and residents with many children collect and commercialise more mangrove resources than others and should be continually involved in sensitization and community engagement to foster the sustainable use of mangroves.

2023

Emotional experiences after a disaster

Henriet E, de Longueville F, Henry S. 2023. Contrasted place-based emotional experiences after a disaster. International Journal of Disaster Risk Reduction 98:104118. DOI: 10.1016/j.ijdrr.2023.104118.

Emotion-place-disaster research tends to focus more on people and communities than on places and their specificities. Our study aims to explore disparities in people's place-based emotional experiences in the recovery period in a region of the Philippines affected by Typhoon Haiyan. We used anoriginal data collection game in which respondents were asked to associate pictures of places with emoticons and to explain these associations. A fully integrated mixed data analysis was then used to characterize non-Typhoon and Typhoon-related place-based emotional experiences. The large panel of descriptive results reveals predominantly positive emotional experiences that intertwine tangible and intangible facets of the person-place relationship. A variety of emotions and their meanings, individual and group concerns, and experiences before, during and after the disaster combine to produce contrasting place-based emotional experiences. In particular, the heterogeneity of the material impacts of the Typhoon on places and their implications for disaster recovery are described and discussed. We argue that further developments in the field should take into account the diversity of place-based emotional experiences highlighted in this research, which can improve disaster preparedness and response strategies and play an important role in disaster recovery.

Hazard Impacts, Vulnerability and Perception in Bujumbura (Burundi)

Nsabimana J, Henry S, Ndayisenga A, Kubwimana D, Dewitte O, Kervyn F, Michellier C. 2023. Geo-Hydrological Hazard Impacts, Vulnerability and Perception in Bujumbura (Burundi): A High-Resolution Field-Based Assessment in a Sprawling City. Land 12:1876. DOI: 10.3390/land12101876.

Rapid urbanization, demographic pressure, and sprawl of cities are key factors in the vulnerability and damage related to geo-hydrological hazards. Dysfunctional urban services that favor informal settlements are at the forefront of elements that increase vulnerability. Cases of cities that suffer from geo-hydrological hazards are increasingly reported in many regions, especially in tropical countries in the Global South. Yet, studies on such examples are rare and commonly overlook the human and societal components of hazard risks. Here, we focus on Bujumbura, a city in Africa that has experienced rapid unplanned growth and sprawl into unserviced areas because of the non-application or a lack of a valid urban planning law. After filling in the gap in data collected using high-resolution field surveys and focus group discussions, this study highlights various factors of vulnerability to geo-hydrological hazards in the urban area...

H2O-O2 line shape parameters

Gamache RR, Orphanos N, Vispoel B, Sung K, Toon GC. 2023. Measurements of H2O-O2 line shape parameters and the determination of the intermolecular potential for modified complex Robert-Bonamy calculations. Molecular Physics 0:e2281592. DOI: 10.1080/00268976.2023.2281592.

Water vapor is the principal absorber of infrared radiation in the Earth's atmosphere. It plays an important role in the greenhouse effect and in meteorology. As such, it is very important to correctly model its interaction with light to perform precise remote sensing of any component in our atmosphere, and also to study atmospheres of distant objects with ground-based instruments.
In the study, both laboratory measurements and theoretical calculations were performed to improve the line shape parameters of water vapor transitions. Spectra of water vapor diluted in oxygen (second most abundant gas in our atmosphere) were recorded using a Fourier Transform spectrometer. The line shape parameters were determined using advanced line shape models that take into account fine physical effects. Using these high accuracy data, the intermolecular potential for the H2O-O2 molecular system was determined and calculations were performed using the Modified Complex Robert-Bonamy formalism. The calculations were able to reproduce the measured data with an average percent difference of 0.052% and a standard deviation of 5.108%.
In the future, this intermolecular potential will be used to compute line shape parameters for a very large number of transitions. These data coupled with N2-broadening parameters will allow the determination of air-broadening line shape parameters and their temperature dependence, providing important data for remote sensing applications.

Spatial Optimization Methods for Malaria Risk Mapping

Morlighem C, Chaiban C, Georganos S, Brousse O, van Lipzig NPM, Wolff E, Dujardin S, Linard C. 2023. Spatial Optimization Methods for Malaria Risk Mapping in Sub-Saharan African Cities Using Demographic and Health Surveys. GeoHealth 7:e2023GH000787. DOI: 10.1029/2023GH000787.

Vector-borne diseases, such as malaria, are affected by the rapid urban growth and climate change in sub-Saharan Africa (SSA). In this context, intra-urban malaria risk maps act as a key decision-making tool for targeting malaria control interventions, especially in resource-limited settings. The Demographic and Health Surveys (DHS) provide a consistent malaria data source for mapping malaria risk at the national scale, but their use is limited at the intra-urban scale because survey cluster coordinates are randomly displaced for ethical reasons. In this research, we focus on predicting intra-urban malaria risk in SSA cities—Dakar, Dar es Salaam, Kampala and Ouagadougou—and investigate the use of spatial optimization methods to overcome the effect of DHS spatial displacement....

Wastewater-based epidemiology of COVID-19

Bertels X, Hanoteaux S, Janssens R, Maloux H, Verhaegen B, Delputte P, Boogaerts T, van Nuijs ALN, Brogna D, Linard C, Marescaux J, Didy C, Pype R, Roosens NHC, Van Hoorde K, Lesenfants M, Lahousse L. 2023. Time series modelling for wastewater-based epidemiology of COVID-19: A nationwide study in 40 wastewater treatment plants of Belgium, February 2021 to June 2022. Science of The Total Environment 899:165603. DOI: 10.1016/j.scitotenv.2023.165603.

Wastewater-based epidemiology (WBE) for COVID-19 was applied across Belgium. Wastewater flow rate and population dynamics explain variability in RNA levels. Variants did not explain variability in RNA levels in 38/40 WWTPs (wastewater treatment plants). WBE metrics lead incident cases by at least one week in 15/40 WWTPs. Inter-WWTP variability was observed in terms of lead time and optimal metric...

Cholera dynamics in the Congo

Kayembe HC, Bompangue D, Linard C, Mandja B-A, Batumbo D, Matunga M, Muwonga J, Moutschen M, Situakibanza H, Ozer P. 2023. Drivers of the dynamics of the spread of cholera in the Democratic Republic of the Congo, 2000–2018: An eco-epidemiological study. PLOS Neglected Tropical Diseases 17:e0011597. DOI: 10.1371/journal.pntd.0011597

Though the dynamics of the spread of cholera epidemics in the Democratic Republic of the Congo (DRC) have been extensively studied, the drivers of these spread processes remain unclear. In this eco-epidemiological study, we focused on the spread processes of cholera epidemics originating from the shores of Lake Kivu to the areas out of endemic eastern DRC. The increase in the number of suspected cholera cases, the exacerbation of conflict events, and the number of IDPs (internally displaced persons) in eastern endemic areas were associated with an increased risk of cholera spreading outside the endemic eastern provinces... 

Species- on- the- move

Pecl GT, Kelly R, Lucas C, van Putten I, Badhe R, Champion C, Chen I-C, Defeo O, Gaitan-Espitia JD, Evengård B, Fordham DA, Guo F, Henriques R, Henry S, Lenoir J, McGhie H, Mustonen T, Oliver S, Pettorelli N, Pinsky ML, Potts W, Santana-Garcon J, Sauer W, Stensgaard A-S, Tingley MW, Verges A. Climate-driven ‘species-on-the-move’ provide tangible anchors to engage the public on climate change. People and Nature n/a. DOI: 10.1002/pan3.10495.

In 2019, Sabine Henry (Geography) was invited by the Species-on-the-move group (mainly biologists) to give a talk on human migration at a conference in South Africa (Kruger National Park). She further contributed to a publication where the authors show how species whose distributions are shifting in response to climate change, that is, ‘species-on-the-move’, present an opportunity to engage people with climate change by linking to human values, connections with the places they live in, in a locally relevant yet globally coherent narrative. They propose other ways to engage people currently unconnected with nature, including arts, games or collaborations with rural agriculture ...

Allergy and impact of nitrogen

Ceulemans T, Verscheure P, Shadouh C, Van Acker K, Devleesschauwer B, Linard C, Dendoncker N, Speybroeck N, Bruffaerts N, Honnay O, Schrijvers R, Aerts R. 2023. Environmental degradation and the increasing burden of allergic disease: The need to determine the impact of nitrogen pollution. Frontiers in Allergy 4. https://doi.org/10.3389/falgy.2023.1063982

Environmental nitrogen pollution may have important direct and indirect impacts on plant species composition and productivity on the one hand, and on allergenicity of pollen aeroallergens on the other. Consequently, nitrogen pollution may change the prevalence, incidence, and severity of allergic disease by modifying the places where people live into landscapes with higher pollen exposure, resulting in elevated allergy risks, and increased allergy symptom severity. Nitrogen pollution worldwide urges us to determine the effects on allergy prevalence, allergenicity and symptom severity to understand, prevent, and control these unexplored pathways of nitrogen-driven allergy risks to public health.

Allergy burden and heart rate

Buekers J, Stas M, Aerts R, Bruffaerts N, Dujardin S, Van Nieuwenhuyse A, Van Orshoven J, Chevance G, Somers B, Aerts J-M, Garcia-Aymerich J. 2023. Daily allergy burden and heart rate characteristics in adults with allergic rhinitis based on a wearable telemonitoring system. Clinical and Translational Allergy 13:e12242. DOI: 10.1002/clt2.12242.

Allergic rhinitis includes a certain degree of autonomic imbalance. However, no information is available on how daily changes in allergy burden affect autonomic imbalance. We aimed to estimate associations between daily allergy burden (allergy symptoms and mood) and daily heart rate characteristics (resting heart rate and sample entropy, both biomarkers of autonomic balance) of adults with allergic rhinitis, based on real-world measurements with a wearable telemonitoring system. We could show that daily allergy symptoms and mood are associated with daily heart rate characteristics in adults with allergic rhinitis. A higher allergy symptom score was associated with an increased resting heart rate on the next day, while a higher mood score was related to a more irregular, healthier heart rate on the same day. These results emphasise the role of daily allergy symptoms and mood in the autonomic (im)balance of adults with allergic rhinitis. The presented approach can furthermore easily be adopted in future telemonitoring studies that aim to examine changes in autonomic imbalance at a high resolution.

Insecticide affects phenotypic traits of fish

Mathiron AGE, Gallego G, Silvestre F. 2023. Early-life exposure to permethrin affects phenotypic traits in both larval and adult mangrove rivulus Kryptolebias marmoratus. Aquatic Toxicology:106543. DOI: 10.1016/j.aquatox.2023.106543.

This study explores how a pyrethroid insecticide (permethrin, PM), a compound known for its neurotoxicity, influences the phenotypic traits in larvae and adults of the self-fertilizing fish mangrove rivulus, Kryptolebias marmoratus. Fish individuals were exposed during an early life stage to different concentrations of PM, which had immediate effects at high concentration that are likely to negatively impact their energy allocation and their fitness (diminished growth and activity, negative thigmotaxis and individuals were less likely to capture prey). The data suggest that pyrethroids can become environmental stressors that may induce behavioural variability in a species with naturally very low genetic diversity. Early exposure to low and high PM concentration both affected the role of cortisol levels on contest behaviour later in life, highlighting that a pyrethroid can interact with hormonal mediation of behaviour in fish.

Impact of natural vs. synthetic oestrogens

Baekelandt S, Leroux N, Burattin L, Gérard C, Delierneux C, Robert J-B, Cornet V, Kestemont P. 2023. Estetrol has a lower impact than 17α-ethinylestradiol on the reproductive capacity of zebrafish (Danio rerio). Aquatic Toxicology 259:106505. DOI: 10.1016/j.aquatox.2023.106505.

Natural and synthetic oestrogens are commonly found in aquatic ecosystems. The synthetic oestrogen 17α-ethinylestradiol (EE2) is widely used in oral contraceptives and its ecotoxicological effects on aquatic organisms have been widely reported. The natural oestrogen estetrol (E4) was recently approved for use in a new combined oral contraceptive and, after therapeutic use, is likely to be found in the aquatic environment. However, its potential effects on non-target species such as fish is unknown. In order to characterize and compare the endocrine disruptive potential of E4 with EE2, zebrafish (Danio rerio) were exposed to E4 or EE2 in a fish short-term reproduction assay with sexually mature male and female fish. The data confirmed the strong impact of EE2 on several parameters including an inhibition of fecundity, an induction of vitellogenin both in male and female fish, an alteration of gonadal structures and the modulation of genes involved in sex steroid hormone synthesis in female fish. In contrast, only few significant effects were observed with E4 with no impact on fecundity. The results suggest that the natural oestrogen, E4, presents a more favourable environmental profile than EE2 and is less likely to affect fish reproductive capacity.

Methylmercury and mangrove rivulus

Chapelle V, Lambert J, Deom T, Tessier E, Amouroux D, Silvestre F. 2023. Early-life exposure to methylmercury induces reversible behavioral impairments and gene expression modifications in one isogenic lineage of mangrove rivulus fish Kryptolebias marmoratus. Aquatic Toxicology 258:106474. DOI: 10.1016/j.aquatox.2023.106474.

Methylmercury (MeHg) is a neurotoxic contaminant generated through methylation of heavy metal mercury by anaerobic bacteria in aquatic environments. In the present study we used the mangrove rivulus Kryptolebias marmoratus as model system to determine immediate and delayed behavioral impairments and associated molecular mechanisms following an early exposure to MeHg. We reported for the first time that MeHg exposure during early life stages can significantly impair behaviors and gene expression in rivulus larvae, but we didn't find these effects after a detoxification period of several months. Our results suggest implications of aminergic system and its neurotransmitters, redox/methylation trade-off and possibly other epigenetic mechanisms in MeHg neurotoxicity underlying behavioral alterations in rivulus.

Nitrogen pollution and allergies

Ceulemans T, Verscheure P, Shadouh C, Van Acker K, Devleesschauwer B, Linard C, Dendoncker N, Speybroeck N, Bruffaerts N, Honnay O, Schrijvers R, Aerts R. 2023. Environmental degradation and the increasing burden of allergic disease: The need to determine the impact of nitrogen pollution. Frontiers in Allergy 4. https://doi.org/10.3389/falgy.2023.1063982

Allergic rhinitis, conjunctivitis, and asthma are common manifestations of allergies caused (among others) by pollen allergens. The allergenicity of pollen aeroallergens may be influenced by environmental nitrogen pollution that directly and indirectly impacts on plant species composition and. Thus, nitrogen pollution may change the prevalence, incidence, and severity of allergic disease by modifying the places where people live into landscapes with higher pollen exposure, resulting in elevated allergy risks, and increased allergy symptom severity. Factors such as allergy prevalence, allergenicity and symptom severity need to be explored to understand, prevent, and control nitrogen-driven allergy risks to public health.

Acute toxicity of insecticides in fish

Agbohessi P, Olowo L, Degila B, Houedjissi G, Imorou Toko I, Mandiki SNM, Kestemont P. 2023. Comparative assessment of acute toxicity and histological changes in liver of African catfish Clarias gariepinus exposed to cotton insecticides. Journal of Environmental Science and Health, Part B 0:1–14. DOI: 10.1080/03601234.2023.2168445.

This study investigated the acute toxicity of African catfish (Clarias gariepinus) to insecticides currently used in Benin cotton fields, including Thalis, Vizir, Abamectin, Pyrinex Quick, Chlorpyrifos and Pyro with emphasis on liver histopathological effects. Juveniles of C. gariepinus were exposed for 96 h to increasing concentrations of each pesticide. Lethality was high at very low doses for Vizir, Pyrinex, and Pyro, indicating a high toxicity to C. gariepinus juveniles. During the experiments, the morphological and behavioral responses (discoloration, hyperactivity, lethargy, etc.) were observed in exposed fish, hypothesizing the neurotoxicity of these pesticides. Histopathological alterations observed in liver of contaminated fish were regressive changes, such as necrosis, vacuolation, bleeding, nuclear degeneration, hepatocytes degeneration, sinusoids dilatation, etc. Vizir induced the highest histological alteration indices while the lowest were induced by Thalis, confirming the highest toxicity of Vizir. These results indicate that acute concentrations of these insecticidal molecules have destructive effects on the liver of C. gariepinus.

Fast response of microbiota and immune reaction to bacterial infection

Redivo B, Derôme N, Kestemont P, Cornet V. 2023. The Pathogen Aeromonas salmonicida achromogenes Induces Fast Immune and Microbiota Modifications in Rainbow Trout. Microorganisms 11:539. DOI: 10.3390/microorganisms11020539.

Environmental stressors can disrupt the relationship between the microbiota and the host and lead to the loss of its functions. Among them, bacterial infection caused by Aeromonas salmonicida, the causative agent of furunculosis, results in high mortality in salmonid aquaculture. Here, rainbow trout were exposed to A. salmonicida achromogenes and its effects on the taxonomic composition and structure of the microbiota was assessed on different epithelia (gills, skin, and caudal fin) and the infection by the pathogen and immune gene responses were evaluated in the head kidney. The results show that infection with A. salmonicida achromogenes significantly altered the diversity of microbiota in the gill, skin, and caudal fin in rainbow trout. In particular, beta diversity measurements showed that the gill microbiota was altered only 6 h after infection, subsequently affecting the skin and caudal fin microbiota, indicating that the gills may be the gateway to this infection. Negative binomial GLMs, associated correlation networks and dysbiosis ratios clearly revealed significant changes in the different microbiota. Along with the dysbiosis, the immune system attempted to cope with the infection by producing pro-inflammatory cytokines, resulting in high stress levels in the fish. A delayed response in the expression of antimicrobial compounds was also observed 24 h after infection. Therefore, we demonstrated that furunculosis not only damages the immune system but also induces dysbiosis in a tissue- and time-dependent manner post-infection.

Non-LTE spectroscopy of the tetradecad region of methane recorded in a hypersonic flow

Dudás E, Vispoel B, Gamache RR, Rey M, Tyuterev VG, Nikitin AV, Kassi S, Suas-David N, Georges R. 2023. Non-LTE spectroscopy of the tetradecad region of methane recorded in a hypersonic flow. Icarus:115421. DOI: 10.1016/j.icarus.2022.115421.

Methane, a minor component of the Earth's atmosphere, has significant effects on climate and atmospheric chemistry. It is the third greenhouse gas on Earth (after water vapor and carbon dioxide), with a global warming potential 21 times greater than CO2. The determination of spectroscopic parameters is crucial to analyze infrared spectra and understanding the physical chemical processes undergoing in our atmosphere.
Methane has also been detected in space (Titan, Jupiter, Uranus, exoplanets). It is one of the proxies for potential life that researchers are looking at. On hot-Jupiter or hot-Neptune, methane is a major component. This giant type of planet has hot atmospheric temperatures (~1000K as such exoplanet are orbiting close to their parent stars). Much information can be extracted from infrared spectra recorded by space instruments. It requires the ability to model the radiative transfer response of the studied atmosphere. This is very complicated for methane because it has a complex vibrational energy structure making computational predictions difficult at high temperature. Because of the temperature and pressure conditions of this type of exoplanet, their atmospheres are often in non-local thermodynamic equilibrium (NLTE). This happens when the number of collisions is not sufficient, resulting in a population that deviates from the Boltzmann law while the molecule velocity distribution remains Maxwellian.
In this study, a cavity ring down spectrometer was used to study methane spectra in NLTE conditions obtained by hypersonic expansion of a pre-heated mixture of argon and methane. A close comparison with available data in literature reveals discrepancies discussed in the paper. The effects, that are at the origin of the differences, are not widely incorporated in NLTE radiative transfer models. In addition, new hot band transitions were assigned and provided for usage in future databases.

2022

Climate Change and Demography

Henry S. 2022. Climate Change and Demography. In: Population and Development Issues. John Wiley & Sons, Ltd, 213–235. DOI: 10.1002/9781394156009.ch9

Starting with a brief overview of climate change, based on the reports of the Intergovernmental Panel on Climate Change, this book chapter discusses the impacts of climate change on demographic factors: fertility and its inevitable inertia, mortality and health, and, finally, migrations, probably the subject mentioned the most often. A case study demonstrates the so-called trapped populations, which are highly vulnerable to climate change, but too poor to adequately cope with it. The monsoon pattern, the Indian Ocean, the intertropical convergence zone and the North Atlantic oscillation are all elements of a climatic sub-system influencing regional meteorology. There are two ways of fighting against climate change: mitigation, by reducing greenhouse gas emissions and protecting ecosystems and adaptation, by putting in place strategies to reduce the harmful effects of climate change.

Predictors of Malaria

Morlighem C, Chaiban C, Georganos S, Brousse O, Van de Walle J, van Lipzig NPM, Wolff E, Dujardin S, Linard C. 2022. The Multi-Satellite Environmental and Socioeconomic Predictors of Vector-Borne Diseases in African Cities: Malaria as an Example. Remote Sensing 14:5381. DOI: 10.3390/rs14215381.

Remote sensing has been used for decades to produce vector-borne disease risk maps aiming at better targeting control interventions. However, the coarse and climatic-driven nature of these maps largely hampered their use in the fight against malaria in highly heterogeneous African cities. Remote sensing now offers a large panel of data with the potential to greatly improve and refine malaria risk maps at the intra-urban scale. This research aims at testing the ability of different geospatial datasets exclusively derived from satellite sensors to predict malaria risk in two sub-Saharan African cities: Kampala (Uganda) and Dar es Salaam (Tanzania). Using random forest models, we predicted intra-urban malaria risk based on environmental and socioeconomic predictors using climatic, land cover and land use variables among others. The combination of these factors derived from different remote sensors showed the highest predictive power, particularly models including climatic, land cover and land use predictors. However, the predictive power remained quite low, which is suspected to be due to urban malaria complexity and malaria data limitations. While huge improvements have been made over the last decades in terms of remote sensing data acquisition and processing, the quantity and quality of epidemiological data are not yet sufficient to take full advantage of these improvements.

Accessibility to health services

Bihin J, De Longueville F, Linard C. 2022. Spatial accessibility to health facilities in Sub-Saharan Africa: comparing existing models with survey-based perceived accessibility. International Journal of Health Geographics 21:18. DOI: 10.1186/s12942-022-00318-z.

To improve access to public health in sub-Saharan Africa, it is essential to map geographical accessibility to health services. Different methods exist to estimate geographical accessibility, but little is known about the ability of these methods to represent the experienced accessibility of the population, and about the added-value of sophisticated and data-demanding methods over simpler ones. This study compares the most used methods to survey-based perceived accessibility in 12 sub-Saharan African countries. Analysis suggests that, at medium spatial resolution and using globally-consistent input datasets, the use of sophisticated and data-demanding methods is difficult to justify as their added value over a simple Euclidian distance method is not clear. Further, all modelled accessibilities are better correlated with perceived accessibility in rural than urban contexts and for population who do not have access to motorized transportation.

A census from heaven

Georganos S, Hafner S, Kuffer M, Linard C, Ban Y. 2022. A census from heaven: Unraveling the potential of deep learning and Earth Observation for intra-urban population mapping in data scarce environments. International Journal of Applied Earth Observation and Geoinformation 114:103013. DOI: 10.1016/j.jag.2022.103013.

Urban population distribution maps are vital to monitor the Sustainable Development Goals, appropriately allocating resources such as vaccination campaigns, and facilitating evidence-based decision making. Typically, such maps result from census data that, in several low- and middle-income countries, may be unreliable or unsuitable, severely limiting the quality of these maps. Here, a novel framework uses multisource Earth Observation (EO) information such as Sentinel-2 and very-high-resolution Pleiades imagery, openly available building footprint datasets, and deep learning (DL) architectures, providing end-to-end solutions to the production of high quality intra-urban population distribution maps in data scarce contexts. The results from case studies in Sub-Saharan Africa, namely Dakar (Senegal), Nairobi (Kenya) and Dar es Salaam (Tanzania), emphasize that the combination of DL and EO data is very potent and can successfully capture relationships between the retrieved image features and population counts at fine spatial resolutions (100 meter). Moreover, for the first time, a state-of-the-art domain adaptation method to predict population distributions in Dar es Salaam and Nairobi (R = 0.39, 0.60) that did not require national census or survey data from Kenya or Tanzania, but only a sample of training locations from Dakar. The DL architecture is based on a modified ResNet-18 model with dual-streams to analyze multi-modal data. These findings prepare for a new generation of urban population products that are an output of end-to-end solutions, can be updated frequently and rely completely on open data.

SARS-CoV-2 Surveillance in Belgian Wastewaters

Janssens R, Hanoteaux S, Maloux H, Klamer S, Laisnez V, Verhaegen B, Linard C, Lahousse L, Delputte P, Terwagne M, Marescaux J, Pype R, Didy C, Dierick K, Van Hoorde K, Lesenfants M. 2022. SARS-CoV-2 Surveillance in Belgian Wastewaters. Viruses 14:1950. DOI: 10.3390/v14091950.

Wastewater-based surveillance was conducted by the national public health authority to monitor SARS-CoV-2 circulation in the Belgian population. Over 5 million inhabitants representing 45% of the Belgian population were monitored throughout 42 wastewater treatment plants for 15 months comprising three major virus waves. During the entire period, a high correlation was observed between the daily new COVID-19 cases and the SARS-CoV-2 concentration in wastewater corrected for rain impact and covered population size. Three alerting indicators were included in the weekly epidemiological assessment: High Circulation, Fast Increase, and Increasing Trend. These indicators were computed on normalized concentrations per individual treatment plant to allow for a comparison with a reference period as well as between analyses performed by distinct laboratories. When the indicators were not corrected for rain impact, rainy events caused an underestimation of the indicators. Despite this negative impact, the indicators permitted us to effectively monitor the evolution of the fourth virus wave and were considered complementary and valuable information to conventional epidemiological indicators in the weekly wastewater reports communicated to the National Risk Assessment Group.

Residential green space, gardening, and subjective well-being

Krols J, Aerts R, Vanlessen N, Dewaelheyns V, Dujardin S, Somers B. 2022. Residential green space, gardening, and subjective well-being: A cross-sectional study of garden owners in northern Belgium. Landscape and Urban Planning 223:104414. DOI: 10.1016/j.landurbplan.2022.104414.

The contribution of domestic gardens to the benefits of urban green spaces and the biodiversity therein on human health and well-being is not well known. Using data from a cross-sectional sample (n = 587) of domestic garden owners in Flanders and Brussels, associations between residential green space quality in and around domestic gardens, green space related activities and socioeconomic background variables of the gardeners, and self-reported health (stress and depression) were investigated with structural equation models. Higher exposure to green space was associated with lower stress and depression levels. Further, the quality of the garden, which is a function of size and diversity, and nature relatedness also had an impact on subjective well-being. Nature relatedness therefore seems to play a key role in the pathway linking gardens to improved health. Improving biodiversity and ecosystem services in gardens could potentially improve human health and well-being, and contribute to the conservation of biodiversity in urban environments.

Green space & mental health benefits

Aerts R, Vanlessen N, Dujardin S, Nemery B, Van Nieuwenhuyse A, Bauwelinck M, Casas L, Demoury C, Plusquin M, Nawrot TS. 2022. Residential green space and mental health-related prescription medication sales: An ecological study in Belgium. Environmental Research 211:113056. DOI: 10.1016/j.envres.2022.113056.

The incidence of depression and other psychiatric disorders, e.g. mood disorders and schizophrenia, is particularly high in urban populations which may be related to environmental stress (chronic and acute exposures to heat, noise, light at night, and air pollution, all common in urban environments). Vegetation may mitigate these detrimental exposures and improve or protect mental health. This nationwide ecological study examined whether medication sales (aggregated data from 2006 - 2014) for mood disorders in Belgium were associated with relative covers of four different green space types, i.e. woodland, low-green, residential gardens, and grassland. Generalized mixed effects models were used to investigate associations between relative covers of woodland, low-green, grassland, and garden, and average annual medication sales. Models were adjusted for socio-economic background variables, urban-rural differences, and administrative region, and included random effects of latitude and longitude. In nationwide models, a 10% increase in relative cover of woodland, garden, and grass was associated with a 1–2% decrease in medication sales. In stratified models, a 10% increase in relative cover of any green space type in urban census tracts was associated with a decrease of medication sales by 1–3%. Thus, living in green environments may be beneficial for adult mental health. Results underline the importance of conserving green space in our living environment, for the conservation of biodiversity and for human health.

Preferred routes of cholera in RDC

Kayembe HCN, Bompangue D, Linard C, Muwonga J, Moutschen M, Situakibanza H, Ozer P. 2022. Modalities and preferred routes of geographic spread of cholera from endemic areas in eastern Democratic Republic of the Congo. PLOS ONE 17:e0263160. DOI: 10.1371/journal.pone.0263160.

Cholera is endemic along the Great Lakes Region, in eastern Democratic Republic of the Congo (DRC), but outbreaks spread to other areas, also due to perpetual conflicts. This study explores the modalities and main routes of this geographic spread. Historical reconstruction of major outbreak expansions of cholera since its introduction in eastern DRC, maps of distribution and spatiotemporal cluster detection analyses of cholera data from passive surveillance (2000–2017) were used to describe the spread dynamics. Four modalities of geographic spread and their likely main routes from the source areas of epidemics to other areas were identified: in endemic eastern provinces, and in non-endemic provinces of eastern, central and western DRC. The higher the number of conflict events reported in eastern DRC, the greater the geographic spread of cholera across the country. Thus, the dynamics of the spread of cholera follow a fairly well-defined spatial logic and can therefore be predicted. These results could contribute to the development of a plan to build resilience in health zones iteratively affected by epidemic waves spreading from endemic areas to achieve the 2030 goals of reducing cholera as a major public health threat.

Mangrove ecosystem services and human wellbeing

Gnansounou SC, Salako KV, Sagoe AA, Mattah PAD, Aheto DW, Glèlè Kakaï R. 2022. Mangrove Ecosystem Services, Associated Threats and Implications for Wellbeing in the Mono Transboundary Biosphere Reserve (Togo-Benin), West-Africa. Sustainability 14:2438. DOI: 10.3390/su14042438.

Mangroves are important coastal ecosystems delivering crucial services to humans. This study explored the diversity of mangrove ecosystem services, their associated threats as well as their contribution to livelihoods and wellbeing of coastal communities in the Mono Transboundary Biosphere Reserve (MTBR) located between Benin and Togo. Most important were provisioning services followed by supporting services, regulating services and cultural services. Major threats to mangrove ecosystem services were changes in water salinity, mangrove overharvesting and illegal, unreported and unregulated fishing. Most of the interviewed persons indicated that the current flow of provisioning, regulating and cultural services does not sustain their wellbeing and livelihoods. However, the perception varied significantly across respondents’ gender, ethnical groups, educational background and country. The two countries showed some similarities but also highlighted important differences which can assist the sustainable management of mangroves in the MTBR.

 

How COVID-19 impacts on internally displaced persons

Ozer P, Dembele A, Yameogo SS, Hut E, de Longueville F. 2022. The impact of COVID-19 on the living and survival conditions of internally displaced persons in Burkina Faso. World Development Perspectives 25:100393. DOI: 10.1016/j.wdp.2022.100393.

Burkina Faso hosts the fourth highest number of conflict-related internal displaced persons (IDPs) in the world. These people have to cope simultaneously with the full spectrum of environmental, social and health-related stresses in the long, medium and short term, respectively. We seek to compare the living conditions of IDPs before and during the lockdown implemented by the authorities (27.3.-5.5.2020) to contain the spread of the virus. 84.9% of the IDPs surveyed had no income-generating activities during the lockdown and the activities of the remaining 15.1% were greatly scaled-down. For a large majority of them, their living conditions, already described as difficult under ‘normal’ circumstances (insufficient food, insignificant financial assistance, or difficult access to health care), further deteriorated. In addition, IDPs were unable to leave the camps or regions where they were located to search for better living conditions or to return home. These IDPs, like many in the sub-region and around the world, therefore require urgent assistance from the authorities and humanitarian NGOs, as the slightest new stress is likely to considerably worsen their already vulnerable state.

Distributions of allergenic tree species in urban environments

Dujardin S, Stas M, Van Eupen C, Aerts R, Hendrickx M, Delcloo AW, Duchêne F, Hamdi R, Nawrot TS, Van Nieuwenhuyse A, Aerts J-M, Van Orshoven J, Somers B, Linard C, Dendoncker N. 2022. Mapping abundance distributions of allergenic tree species in urbanized landscapes: A nation-wide study for Belgium using forest inventory and citizen science data. Landscape and Urban Planning 218:104286. DOI: 10.1016/j.landurbplan.2021.104286.

Mapping the distribution of allergenic plants in urbanized landscapes is of high importance to evaluate its impact on human health. However, data is not always available for the allergy-relevant species such as alder, birch, hazel, especially within cities where systematic inventories are often missing or not readily available. Thanks to observations by non-scientific citizens, we were able to carry out a detailed mapping of three allergenic tree species: alder, birch and hazelnut. This mapping covers the entire Belgian territory and has many applications, notably in the field of health and the management of natural areas in both urban and rural areas. It is available on an online mapping platform created especially for the occasion: https://s-dujardin.shinyapps.io/shinyapprespirit/

Microplastics and zebrafish

Rabezanahary ANA, Piette M, Missawi O, Garigliany M-M, Kestemont P, Cornet V. 2023. Microplastics alter development, behavior, and innate immunity responses following bacterial infection during zebrafish embryo-larval development. Chemosphere 311. DOI: 10.1016/j.chemosphere.2022.136969.

Although the hazards of microplastics (MPs) have been explored, no complete data exists on the effect of MPs on the egg chorion. This study aims to evaluate the modification of immune responses, metabolism, and behavior of zebrafish larvae (Danio rerio) depending on the moment of exposure. Larvae were exposed to 5 μm polystyrene microbeads at different concentration and times of exposure, followed by a bacterial challenge to stimulate their immune reaction. In the following, their swimming activity, gene expression related to oxidative stress and immune system responses were assessed. Results show effects on the early stage of zebrafish development even before their ingestion. This toxic effect also led to a delayed impact by hindering the larvae's swimming activity. A short exposure to the highest concentration of few days is sufficient to modulate the immune system response and the apoptosis regulation pathway. Longer exposure led to inhibition of the cytoprotective and immune system gene transcription which more likely promoted cell apoptosis in larvae. The results underline the importance of the moment of exposure when studying MPs in developing embryos and larvae as even in the absence of direct contact, MPs can impact the larvae in the short and potentially long term.

Pesticide residues on Nile Tilapia

Agbohessou PS, Mandiki SNM, Mbondo Biyong SR, Cornet V, Nguyen TM, Lambert J, Jauniaux T, Lalèyè PA, Kestemont P. 2022. Intestinal histopathology and immune responses following Escherichia coli lipopolysaccharide challenge in Nile tilapia fed enriched black soldier fly larval (BSF) meal supplemented with chitinase. Fish & Shellfish Immunology 128:620–633. DOI: 10.1016/j.fsi.2022.08.050.

 This study aimed to determine to what extend the addition of chitinase to black soldier fly larvae (BSF) meals enriched with either PUFA or LC-PUFA could improve the gut health of Nile tilapia and increase its immune status. The results showed that supplementation of 5 g/kg of chitinase to a BSF-based diet enriched with LC-PUFA improved growth, prevented histological changes in the proximal intestine and increased lysozyme activity of Nile tilapia after a challenge with LPS from E. coli. Furthermore, when 5 g/kg of chitinase is added to the BSF diet, it acts synergistically with LC-PUFA to regulate the expressions of pro-inflammatory il-1β and il-6 genes. Nevertheless, a weak stimulation of the immune system was observed by the combination of chitinase, BSF and/or LPS. Therefore, it is useful to optimize the use of chitinase as an aquatic feed supplement when replacing FM with BSF for sustainability.

Roach and Great Cormorant

Paquet J-Y, Otjacques W, Libois R, Pourignaux F, Kestemont P. 2022. Effects of Roach Rutilus rutilus Collapse on Abundance, Distribution and Diet of Great Cormorants Phalacrocorax carbo in a Large River in North-West Europe. Ardea 109:429–441. DOI: 10.5253/arde.v109i1.a14.

Aquatic habitats are subject to multifactorial changes including global warming, invasive species colonisation, modification of organic and micro-pollutant discharge and, for large rivers in Europe, drastic physical modification (e.g. channelisation, impoundments). The Meuse River in Belgium is one of these multi-stressed environments, in which recent decreases of fish populations were observed, with the loss of 90% of Roach Rutilus rutilus biomass in only a few years. In the light of this fish stock collapse, diet modification and local population evolution of a key avian predator, the Great Cormorant Phalacrocorax carbo, were examined. The diet composition and daily consumption rates of the Great Cormorants feeding in the river were largely similar to that seen before the fish population collapsed. Numbers of wintering Great Cormorants decreased by 90%, as did Roach numbers, and thus the predation pressure was adjusted to the decreased fish availability. The number of night-roosts and locations remained unchanged and no redistribution to adjacent habitats was observed at the regional scale. We suggest a bottom-up chain of responses where a fish collapse forced a reduction in Cormorant numbers, being the main piscivorous avian predator, rather than a modification of Cormorant prey composition and/or a local redistribution to adjacent wetlands (top-down). The factors that govern the establishment of a small and productive breeding population remain to be explained, but we hypothesise that the start of breeding could well have been alleviated by the large decrease in number of wintering birds.

Effects of pesticide residues on Nile Tilapia

Guedegba NL, Ammar IB, Houndji A, Toko II, Van De Merckt L, Agbohessi PT, Mandiki SNM, Marie-Louise SCIPPO, Kestemont P. 2022. Integrated biomarker response to assess the effects of pesticide residues on Nile Tilapia in aquatic ecosystems contaminated by cotton-field effluents. Chemosphere:135407. DOI: 10.1016/j.chemosphere.2022.135407.

 

An in-situ study combined with an integrated biomarker response was used to evaluate the impact of agricultural effluents in the physiological responses of Nile tilapia reared in cages and enclosures of water reservoirs in two sites and types of infrastructure in cotton field areas in North Benin. All results on the contamination status in both ecosystems and the impact of pesticide presence and concentrations on several biomarker endpoints, namely the immune and reproductive functions, the neurotoxicity and tissue's alterations integrated into an IBR approach highlighted that the Batran water reservoir is a harmful ecosystem for fish. It could further be demonstrated that the level of contamination and the effects of pesticides were higher in fish reared in enclosures compared to those reared in cages, confirming the hypothesis that the access to sediments intensified the pesticide burden on fish. Finally, males seemed more sensitive than females especially due to the estrogenic induction of their reproductive system by pesticides. Using male individuals as bioindicators could enhance the sensitivity of the used biomarkers and help detecting the impact of lower pesticide concentrations.

Techniques for high-resolution spectroscopy

Mangold M, Allmendinger P, Hayden J, Eigenmann F, Browet O, Lepère M, Gianella M, Emmenegger L, Hugi A. 2022. High-resolution spectroscopy with quantum cascade laser frequency combs. SPIE digital library DOI: 10.1117/12.2609711.

Optical frequency comb spectroscopy has proven an indispensable tool for high-resolution spectroscopy. QCL frequency combs offer the possibility to explore the mid-infrared spectral range. However, they suffer from large repetition frequencies which make them seemingly unsuitable for high resolution spectroscopy. We present three measurement modes overcoming this limitation. The rapid-sweep technique allows to retrieve the full high-resolution spectrum in 6ms, the step-sweep technique allows for high-resolution spectroscopy with spectral resolution <5e-4 cm-1. As a last technique we present the time-resolved step-sweep approach enabling high-resolution spectra of sub-millisecond-lived samples. It was assessed in a study of cold gases in supersonic beams.

Biomonitoring with rainbow trout

Beghin M, Paris-Palacios S, Mandiki SNM, Schmitz M, Palluel O, Gillet E, Bonnard I, Nott K, Robert C, Porcher J-M, Ronkart S, Kestemont P. 2022. Integrative multi-biomarker approach on caged rainbow trout: A biomonitoring tool for wastewater treatment plant effluents toxicity assessment. Science of The Total Environment 838:155912. DOI: 10.1016/j.scitotenv.2022.155912.

The present study suggests that fish exposed to wastewater effluents experienced metabolic costs, altered immune functions and a moderate inflammatory syndrome. It further demonstrated that the application of a multi-biomarker approach on caged rainbow trout is a valuable biomonitoring tool to assess the impact of WWTP effluents on aquatic organisms. The application of the IBR index on the data highlights a response pattern that is representative for the exposure to this source of contamination by pointing out sensitive biomarkers and physiological functions. However, the same approach should be applied to different WWTPs to confirm our results, as the composition of the effluents and the characteristics of the receiving environment vary from station to station. Furthermore, our findings stress the need to improve the quality of our aquatic ecosystems to preserve their biodiversity and maintain essential ecosystem services they provide.

A mid-infrared dual-comb spectrometer

Lepère M, Browet O, Clément J, Vispoel B, Allmendinger P, Hayden J, Eigenmann F, Hugi A, Mangold M. 2022. A mid-infrared dual-comb spectrometer in step-sweep mode for high-resolution molecular spectroscopy. Journal of Quantitative Spectroscopy and Radiative Transfer 287:108239. DOI: 10.1016/j.jqsrt.2022.108239.

To meet the challenges of high-resolution molecular spectroscopy, increasingly sophisticated spectroscopic techniques were developed. For a long time FTIR and laser-based spectroscopies were used for these studies. The recent development of dual-comb spectroscopy at high-resolution makes this technique a powerful tool for gas phase studies. We report on the use and characterization of the IRis-F1, a tabletop mid-infrared dual-comb spectrometer, in the newly developed step-sweep mode. The resolution of the wavenumber axis is increased by step-wise tuning (interleaving) and accurate measurement of the laser center wavelength and repetition frequency. Doppler limited measurements of N2O and CH4 reveal a wavenumber accuracy of 10−4 cm−1 on the covered range of > 50 cm−1. Measured half-widths of absorption lines show no systematic broadening, indicating a negligible instrument response function. Finally, measurements of nitrogen pressure broadening coefficients in the ν4 band of methane show that quantum cascade laser dual-comb spectroscopy in step-sweep mode is well adapted for measurements of precision spectroscopic data, in particular line shape parameters.

Partition sums for non-local thermodynamic equilibrium conditions for nine molecules of importance in planetary atmospheres

Gamache RR, Vispoel B, Rey M, Tyuterev V, Barbe A, Nikitin A, Polyansky OL, Tennyson J, Yurchenko SN, Császár AG, Furtenbacher T, Perevalov VI, Tashkun SA. 2022. Partition sums for non-local thermodynamic equilibrium conditions for nine molecules of importance in planetary atmospheres. Icarus 378:114947. DOI: 10.1016/j.icarus.2022.114947.

Partition Sums are a very useful quantity in chemistry and physics. They are used to determine the population of molecules as a function of quantum state, and can be used to write thermodynamic functions (internal energy, enthalpy, entropy…), heat capacity, etc. In spectroscopy, the population factor is needed to determine the spectral line intensity of ro-vibrational transitions.
The intensity of spectral lines is one of the crucial information that is required to study planetary atmospheres, as the radiative transfer equations are solved by following the radiation through roughly isothermal-isobaric layers. As long as the pressure and temperature are not too low, the number of collisions per unit of time is sufficient for the populations of the quantum energy states to follow the Boltzmann law and the molecular velocity distribution remains Maxwellian. This is called the Local-Thermodynamic Equilibrium (LTE) (see previous paper Gamache et al. JQSRT, 271 (2021) 107713). If the number of collisions is not sufficient enough, the population deviate from the Boltzmann law while the molecule velocity distribution remains Maxwellian. This is called the Non-Local Thermodynamic Equilibrium (NLTE). For example, this appends for CO2 in Earth’s atmosphere above 70 km affecting the role of CO2 on the energy budget. For planetary atmospheres, NLTE conditions have been found to occur in exoplanet upper atmospheres, hot Jupiter…
In this paper, the determination of the internal vibrational and rotational partition functions needed for NLTE computations is undertaken for nine molecules that are often observed in NLTE conditions and are abundant in planetary and exoplanet atmospheres: H2O, CO2, O3, N2O, CO, CH4, NO, NO2 and OH. The methods of calculations are reviewed for each molecule/isotopologue. Data and codes are provided for fast recall partitions functions in NLTE conditions.

2021

The spread of cholera in DRC

Kayembe HCN, Linard C, Bompangue D, Muwonga J, Moutschen M, Situakibanza H, Ozer P. 2021. The spread of cholera in western Democratic Republic of the Congo is not unidirectional from East–West: a spatiotemporal analysis, 1973–2018. BMC Infectious Diseases 21:1261. DOI: 10.1186/s12879-021-06986-9.

Cholera outbreaks in western Democratic Republic of the Congo (DRC) are thought to be primarily the result of westward spread of cases from the Great Lakes Region. The aim of this study shows that beyond westward and cross-border spread in the West Congo Basin from the Great Lakes Region, other dynamics of cholera epidemic propagation occurred from neighbouring countries, such as Angola, to non-endemic provinces of southwestern DRC. Space–time clustering analyses sequentially detected clusters of cholera cases from southwestern DRC to the northern provinces, demonstrating a downstream-to-upstream spread along the Congo River. Thus, the spread of cholera in western DRC is not unidirectional from endemic areas in eastern DRC. Alternative patterns of spatial spread in this part of the country are effectively possible, in particular from downstream to upstream provinces along the Congo River. These patterns of spread should also be considered as preferential trajectories of cholera in the western provinces of the DRC. Policies and strategies should focus on cross-border collaboration between the countries in the West Congo Basin to achieve the goals of reducing cholera as a major public health concern by 2030.

COVID-19 hospital incidence in Belgium

Dellicour S, Linard C, Van Goethem N, Da Re D, Artois J, Bihin J, Schaus P, Massonnet F, Van Oyen H, Vanwambeke SO, Speybroeck N, Gilbert M. 2021. Investigating the drivers of the spatio-temporal heterogeneity in COVID-19 hospital incidence—Belgium as a study case. International Journal of Health Geographics 20:29. DOI: 10.1186/s12942-021-00281-1.

The COVID-19 pandemic shows significant spatial and temporal variation at the sub-national level. Identifying the drivers of resulting hospitalisation incidence to predict, mitigate and manage epidemic surges is difficult due to the lack of spatially-explicit health data. This study proposes an analytical framework to investigate these drivers when data are only available at the hospital level. It is based on the delimitation of hospital catchment areas, which allows analysing associations between hospitalisation incidence and spatial or temporal covariates. The spatial analyses reveal an association between the hospitalisation incidence and the local density of nursing home residents, which confirms the important impact of COVID-19 in elderly communities of Belgium. The temporal analyses further indicate a pronounced seasonality in hospitalisation incidence associated with the seasonality of weather variables. Taking advantage of these associations, we discuss the feasibility of predictive models based on machine learning to predict future hospitalisation incidence. This reproducible analytical workflow allows performing spatially-explicit analyses of data aggregated at the hospital level and can be used to explore potential drivers and dynamic of COVID-19 hospitalisation incidence at regional or national scales.

Indices of housing quality improve health assessments in African cities

Gadiaga AN, Longueville FD, Georganos S, Grippa T, Dujardin S, Diène AN, Masquelier B, Diallo M, Linard C. 2021. Neighbourhood-level housing quality indices for health assessment in Dakar, Senegal. Geospatial Health 16. DOI: 10.4081/gh.2021.910.

Accurate and detailed data are often lacking in health and socio-economic studies, especially in sub-Saharan cities, that are growing rapidly and reinforce socio-economic inequalities increasing health inequalities. Proxies associated with socioeconomic differences can help to compensate lacking or poor data. Housing quality is a straightforward one. It is a multidimensional concept that includes built and natural environments. This study combines census data with land cover and land use data (remote sensing at very high resolution) to develop an integrated typology of the neighbourhoods in Dakar, Senegal, that is based on housing quality. The results confirm the importance of housing quality as health risk factor. The developed proxy can support geographically targeted health policies at the neighbourhood spatial level, the most appropriate administrative level for interventions.

Green space and allergy symptom severity

Stas M, Aerts R, Hendrickx M, Delcloo A, Dendoncker N, Dujardin S, Linard C, Nawrot T, Van Nieuwenhuyse A, Aerts J-M, Van Orshoven J, Somers B. 2021. Exposure to green space and pollen allergy symptom severity: A case-crossover study in Belgium. Science of The Total Environment 781:146682. DOI: 10.1016/j.scitotenv.2021.146682.

More and more people become allergic to pollen, a trend that will further increase due to urbanization, air pollution and climate change. Green spaces in urban areas should mitigate the latter effects and at the same time improve life quality. This study calculated dynamic exposure on 808 person-days obtained from a cohort of 144 adults residing in Belgium and sensitized to tree pollen. Severe allergy was associated with birch pollen levels, ozone and air pollutants on the day of the severe allergy event and the two days before the event. Grass cover, forest cover, Alnus density and Corylus density were protective for severe allergy. However, increased densities of Betula trees was a risk factor. In conclusion, short-term exposure to green space has a protective effect on the physical health of pollen allergy sufferers especially if the density of allergenic trees is low. Spatio-temporal detail is important in environmental health studies on exposure to green space as well as pollen and air pollutants.

Local variations in tree pollen composition

Stas M, Aerts R, Hendrickx M, Bruffaerts N, Dendoncker N, Hoebeke L, Linard C, Nawrot T, Van Nieuwenhuyse A, Aerts J-M, Van Orshoven J, Somers B. 2021. Association between local airborne tree pollen composition and surrounding land cover across different spatial scales in Northern Belgium. Urban Forestry & Urban Greening 61:127082. DOI: 10.1016/j.ufug.2021.127082.

In European aerobiological networks, airborne pollen concentrations are monitored at building roof-level, i.e. 10−20 meters above ground. This “Hirst-method” is optimal for homogeneous measurements, representing for a 25 and even 50 km radius area. Short-distance transport, however, contributes to the most important pollen peaks and the actual pollen-dose, the one that is relevant to allergenic persons, can differ strongly from the measured regional pollen concentration. This could determine local variations in tree pollen composition with passive samplers at 2m height, and identify the surrounding landscape characteristics that drive them. Corylus and Platanus pollen were associated to urban areas; Populus, Juglans and Fraxinus pollen to agricultural areas; forests and wetlands were sources of Alnus and Quercus pollen. Salix, Populus and Betula pollen were also mainly associated to wetlands. The landscape context drives the airborne tree pollen composition at a meso-scale (1−5 km) rather than at finer scale (20−500 m). Thus, land cover types (e.g. forest, bush land, agricultural lands and wetlands) surrounding urban areas may increase exposure to allergenic pollen in the urban area, potentially affecting the health of a large proportion of the population.

Green space and pollen allergy

Stas M, Aerts R, Hendrickx M, Dendoncker N, Dujardin S, Linard C, Nawrot TS, Van Nieuwenhuyse A, Aerts J-M, Van Orshoven J, Somers B. 2021. Residential green space types, allergy symptoms and mental health in a cohort of tree pollen allergy patients. Landscape and Urban Planning 210:104070. DOI: 10.1016/j.landurbplan.2021.104070

Exposure to green space is often found to improve human physical and mental health. This study investigated its effect on a rarely studied group, tree pollen allergy patients sensitized to hazel, alder and/or birch pollen. Residential green space was associated with reduced mental distress and perceived stress. However, high amounts of allergenic trees in forests near the residence, in particular within a 2 km distance, was associated with more severe allergy symptoms and contributed to mental distress. Nevertheless, this did not affect daily mood. The results contribute evidence for mental health benefits of green space, also for pollen allergy sufferers. There are, however, risks related to specific tree species for both mental and respiratory health during the pollen season which must be further elaborated into recommendations for design of allergy-friendly urban green spaces and other city greening.

20 years of urban mapping in Sub-Saharan Africa

Forget Y, Shimoni M, Gilbert M, Linard C. 2021. Mapping 20 Years of Urban Expansion in 45 Urban Areas of Sub-Saharan Africa. Remote Sensing 13:525. DOI: 10.3390/rs13030525.

By 2050, half of the net increase in the world’s population is expected to reside in sub-Saharan Africa (SSA), driving high urbanization rates and drastic land cover changes. However, the data-scarce environment of SSA limits the understanding of the urban dynamics in the region. The purpose of this study is to produce a reliable multi-temporal dataset of built-up maps for a sample of 45 urban areas in Sub-Saharan Africa at 5 different dates between 1995 and 2015. By leveraging both multi-sensor data fusion to improve built-up detection and the integration of OpenStreetMap data to support the training of the classification models, an automated and low-cost approach is proposed which may be appropriate at larger scales. Further, the results obtained are interpreted through the analysis of built-up expansion and its relationship with population growth.

The HITRAN2020 molecular spectroscopic database

Gordon IE, Rothman LS, Hargreaves RJ, Hashemi R, Karlovets EV, Skinner FM, Conway EK, Hill C, ... Vispoel B, Wagner G, Yachmenev A, Yurchenko SN. 2021. The HITRAN2020 molecular spectroscopic database. Journal of Quantitative Spectroscopy and Radiative Transfer:107949. DOI: 10.1016/j.jqsrt.2021.107949.

The HITRAN database is a compilation of molecular spectroscopic parameters that gathers the needed components for the calculation of transmission and emission of light in gaseous media (atmosphere, residual gases of combustion…). This database is a major effort and contribution of the entire spectroscopic community. The HITRAN database is worldwide used and is one of the golden standard for atmospheric retrievals. In this paper, Bastien Vispoel was involved in the calculation of collisional half-width and line shift, and their temperature dependence, of water vapour transitions, which is of major importance for the study of pollution in Earth’s atmosphere. Calculations were made for about 140 000 transitions and a prediction routine (based on physics) was used for the remaining transitions. An algorithm was developed to fill the database with the available experimental measurements, calculated and predicted data.
HITRAN data are available at www.hitran.org and the HITRAN Application Programming Interface (HAPI).

Effects of pharmaceutical mixtures on juvenile trouts

Beghin M, Schmitz M, Betoulle S, Palluel O, Baekelandt S, Mandiki SNM, Gillet E, Nott K, Porcher J-M, Robert C, Ronkart S, Kestemont P. 2021. Integrated multi-biomarker responses of juvenile rainbow trout (Oncorhynchus mykiss) to an environmentally relevant pharmaceutical mixture. Ecotoxicology and Environmental Safety 221:112454. DOI: 10.1016/j.ecoenv.2021.112454.

Pharmaceuticals are emerging pollutants of concern for aquatic ecosystems where they are occurring in complex mixtures. This study investigates the chronic toxicity of an environmentally relevant pharmaceutical mixture on juvenile rainbow trout (Oncorhynchus mykiss). Five pharmaceuticals (paracetamol, carbamazepine, diclofenac, naproxen and irbesartan) were considered in concentrations comparable to the average one found in the Meuse river, 10-times and 100-times this concentration. Fish were exposed for 42 days. Immunomodulatory and potential neuro-endocrine disruptive effects were observed but only at the highest concentration, 100 times superior to the average environmental one. The mixture’s toxicity was lower than assumed based on previously reported toxic effects of the individual compounds contained in it. The findings imply the importance of investigating mixture interactions as they can modulate drugs bioavailability and toxicity.

TIPS - total internal partition sums

Gamache RR, Vispoel B, Rey M, Nikitin A, Tyuterev V, Egorov O, Gordon IE, Boudon V. 2021. Total internal partition sums for the HITRAN2020 database. Journal of Quantitative Spectroscopy and Radiative Transfer 271:107713. DOI: 10.1016/j.jqsrt.2021.107713.

Total internal partition sums (TIPS) are very useful quantities in chemistry and physics (equation of state, thermodynamic functions, etc.). In molecular spectroscopy, TIPS are used to determine the population of molecules as a function of quantum state, which are needed to determine the intensity of a ro-vibrational transition. In radiative-transfer, TIPS are one of the input parameters needed to compute models to study planetary atmospheres. This work is an update and an extension of previous studies that computes TIPS for 57 molecules and 178 isotopologues present in the new HITRAN2020 database. TIPS were computed for molecules recently added to the HITRAN database, and molecules/isotopologues that were not updated for TIPS2017 have been recalculated using the 2014 CODATA physical constants. The TIPS are determined by various methods depending on the data available in the literature and the shape of the molecule. The TIPS values were computed from 1K to generally 5000K, useful for atmospheric and stellar applications.

Exposure to endocrine disruptors in early life can show altered phenotypes in adulthood

Voisin A-S, Suarez-Ulloa V, Stockwell P, Chatterjee A, Silvestre F. 2021. Genome-wide DNA methylation of the liver reveals delayed effects of early-life exposure to 17-α-ethinylestradiol in the self-fertilizing mangrove rivulus. Epigenetics 0:1–25. DOI: 10.1080/15592294.2021.1921337

This study adds another aspect to the investigation of long-term effects of an early life stage exposure to the endocrine disruptor ethinyl estradiol (EE2) in the fish model mangrove rivulus. A first publication of F. Silvestre and his team that uses the golden standard technique of RRBS on the mangrove rivulus (combining restriction enzymes and high throughput bisulfite sequencing to analyse genome-wide DNA methylation). The most significant result was reported for the nipped-B-like protein B (NIPBL) promoter region with a 21.9% increase of DNA methylation, suggesting that NIPBL could be an important regulator for long-term effects of EE2. The results also suggest a significant role of DNA methylation in intergenic regions and potentially in transposable elements. These data support the ability of early exposure to endocrine disruptors of inducing epigenetic alterations during adulthood, providing plausible mechanistic explanations for long-term phenotypic alteration. Additionally, this work demonstrates the usefulness of isogenic lineages of the self-fertilizing mangrove rivulus to better understand the biological significance of long-term alterations of DNA methylation by diminishing the confounding factor of genetic variability.

Dual-Comb Spectroscopy

Lepère M, Browet O, Leonis S, Clément J, Pitt Allmendinger, Knapp K, Eigenmann F, Mangold M. 2021. Quantum cascade laser dual-comb spectroscopy (DCS) for methane gas mixture studies. DOI: 10.1117/12.2582747.

Methane is a minor constituent of the Earth’s atmosphere. Despite its weak abundance, its effect on climate and atmospheric chemistry is important. Retrievals of atmospheric spectra are very sensitive to the spectroscopic parameters, more specifically to the half-widths. Studies showed that small changes in these parameters can improve the atmospheric retrievals. High resolution measurements are able to meet the needed precision and thus provide very precise spectroscopic parameters required for atmospheric remote sensing.
For a long time FTIR spectroscopy as well as laser-based spectroscopies have been used for these high resolution molecular spectroscopy studies. The recent development of Dual-Comb Spectroscopy (DCS) at high resolution (<0.001 cm-1) makes this technique a powerful tool for gas phase studies. The IRis-F1 is a dual-comb spectrometer building on quantum cascade laser frequency combs. It allows to scan relatively large spectral ranges (> 60 cm-1) with a high resolution (<0.001 cm-1) in the spectroscopically important mid-infrared region (1000-2500 cm-1). In our presentation, we compare spectroscopic properties of the IRis-F1 such as spectral coverage, spectral resolution, measurement time, and signal-to-noise ratio (SNR) with those of other techniques such as FTIR, diode-laser and QCL spectroscopies. Such way, we show that the IRis-F1 spectrometer is very well adapted for measurements of line shape parameters such as individual line intensities, collisional broadenings and pressure-shifts, as well as the line shape itself.
In this work, we measured with the IRis-F1 the half-widths of absorption lines in the nu4 vibrational band of methane diluted in nitrogen at room temperature. Ro-vibrational lines ranged from 1285 to 1335 cm-1. The pressures, measured by Baratron gauges, of methane were very low (<1 mbar), reducing the self-broadening, while those of nitrogen were comprised between 10 and 150 mbar. The half-widths were deduced from fits of theoretical profiles on experimental lineshapes. These profiles take into account several physical effects as the Doppler and collisional broadenings but also the Dicke narrowing due to the molecular confinement. Finally, our results are compared with previous measurements made by FTIR, diode-laser and QCL spectroscopies.

Water vapor line profile at 183-GHz

Koshelev MA, Vilkov IN, Makarov DS, Tretyakov MYu, Vispoel B, Gamache RR, Cimini D, Romano F, Rosenkranz PW. 2021. Water vapor line profile at 183-GHz: Temperature dependence of broadening, shifting, and speed-dependent shape parameters. Journal of Quantitative Spectroscopy and Radiative Transfer 262:107472. DOI: 10.1016/j.jqsrt.2020.107472.

The 183-GHz water vapor transition (31,3 ← 22,0) is a microwave atmospheric diagnostic line of major importance for water vapor remote sensing. It is used for quality control of sensors by several ground-based, airborne and satellite missions, but also often used for validation of radiative transfer models. Observations at 183-GHz are also widely used to feed numerical weather prediction models. An accurate knowledge of its line shape parameters is needed including intensity, pressure broadening and shifting parameters, and their speed- and temperature dependence parameters.

In this work, line shape parameters were studied from experimental and theoretical point of view. Experimental measurements were performed from 219 to 358K using a radio-acoustic detection spectrometer. The line shape parameters were obtained from Voigt and quadratic speed-dependent Voigt line shape profile. The Modified Complex Robert-Bonamy (MCRB) model was used to make calculations of line shape parameters, and their speed- and temperature dependence, in a temperature range of 200-3000K. The measurements and calculations show very good agreement, with some discrepancies of the line shift parameter. The experimental values are in good agreement with previously known values, but have smaller uncertainties. The data include the first measurement of speed-dependent collisional broadening and shifting of the 183-GHz line in the considered temperature range. The agreement between the measured and calculated speed-dependence parameters confirms the capability of the MCRB formalism to evaluate this weak collisional effect.

Evaluation of the impact of the newly-determined line shape parameters on radiative transfer modeling and water vapor retrievals was done for ground-based and satellite instruments. It was shown that consideration of the speed-depend parameters is necessary for accurate estimation of water amount in the atmosphere (neglecting it can introduce systematic errors of 1% to 2%).

Dietary lipids and cadmium exposure in rainbow trout liver

Ferain A, Delbecque E, Neefs I, Dailly H, De Saeyer N, Van Larebeke M, Cornet V, Larondelle Y, Rees J-F, Kestemont P, De Schamphelaere KAC, Debier C. 2021. Interplay between dietary lipids and cadmium exposure in rainbow trout liver: Influence on fatty acid metabolism, metal accumulation and stress response. Aquatic Toxicology 231:105676. DOI: 10.1016/j.aquatox.2020.105676.

The present study aimed at investigating interactive effects between dietary lipids and both short- and long-term exposures to a low, environmentally realistic, cadmium (Cd) concentration. Juvenile rainbow trout were fed four isolipidic diets enriched in either linoleic acid (LA), alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA). Half of the fish fed each diet were aqueously exposed to Cd (short- and long-term exposure) and their liver was harvested for fatty acid profiles. The hepatic fatty acid profile mostly reflected that of the diet. Cd effects on hepatic fatty acid profiles were influenced by the duration of the exposure and the nutritional status of the fish. The biological responses to Cd were also influenced by dietary lipids. Fish fed the ALA-enriched diet seemed to be the least affected by the Cd exposure, as they showed a higher detoxifying ability against Cd, as well as a lower long-term accumulation of Cd in their liver. In contrast, fish fed the EPA-enriched diet seemed to be the most sensitive to a long-term Cd exposure, with an impaired growth performance and a decreased antioxidant capacity.

2020

Peasants’ livelihood strategies in Ecuador

Vanegas R, Demoulin F, Ruivenkamp G, Henry S. 2020. Analysis of the peasants’ livelihood strategies in the Paute basin of Ecuador. Maskana 11:70–80. DOI: 10.18537/mskn.11.02.07.

In world agriculture, three different modes of farming can be discerned: a peasant, an entrepreneurial, and a large-scale corporate (or capitalist) mode of farming. The peasant way of farming is built upon (primarily) family labour. Peasantry still constitutes nearly two-fifths of humanity. This study investigates the livelihood of peasant farmers in the rural area of three parishes in the Paute basin in Ecuador. Applying the Chayanovian and van der Ploeg interpretation frames, three types of peasant households could be distinguished, based upon their specific organizational forms of producing and reproducing their livelihoods. The first one is the subsistence households characterized mainly by their need to balance the limited available labour force. The second type is the growing and mid-advantaged households that represent the innovative labour-force inclined to seek technical assistance and new trading options. The last type is the longstanding and most-advantaged households characterized by the highest availability of labour force (including hiring possibilities) and a strongly market-oriented approach.

Use Games to collect data!

Henriet E, Burnay N, Dalimier J, Hurley J, Henry S. 2020. Challenges and Opportunities of Field-based Data Collection with a Game. Analysis of the Development and use of a Game to Collect Data on People’s Emotional Experience in their Environment. Bulletin of Sociological Methodology/Bulletin de Méthodologie Sociologique:0759106320960885. DOI: 10.1177/0759106320960885.

The authors developed and used a game (Tigo-Tigo) to collect data on people’s emotional experience in their environment in an area hit by a typhoon (Philippines). With the aim of encouraging the use of games for data collection in the field, they provide an in-depth analysis of all phases of the process, from the game development to the experience of the game sessions and the quality of the data produced. Designing a data collection game is creating an immersive experience that get people to share information with the researcher. However challenging to develop as it has to meet both data gathering and game requirements, Tigo-Tigo successfully produced complex data and a positive experience. By following its simple rules, the respondents were led to formulate and share both quantitative (emotion levels) and qualitative (explanations for emotion-environment associations) data. Moreover, the game was motivating and changed the status of participation, as the researchers played with the respondents in an inversed power setting. Finally, its particular interactional structure also improved the quality of the data produced by reducing expectation as well as cultural and translation barriers encountered in the field.

SARS-CoV-2 emergence and diffusion

Vanwambeke SO, Linard C, Gilbert M, Dellicour S. 2020. SARS-CoV-2 emergence and diffusion: a new disease manifesting human–environment interactions and a global geography of health. Current Opinion in Environmental Sustainability 46:43–45. DOI: 10.1016/j.cosust.2020.10.011.

SARS-CoV-2, and the disease it causes, COVID-19, is sweeping through the world, disrupting human activities everywhere. At the time of writing, 35 million cases of COVID-19 have been recorded worldwide. The death toll is now over a million, and the social, economic and associated health burden has been or may become far reaching. The emergence of SARS-CoV-2 illustrates how human–environment interaction should be framing research on pathogen spillover. Furthermore, the geography of human contacts at various scales in our globalized and urbanized world affects its diffusion. Both elements plead for a robust backbone of geography of health, including land use, to understanding disease emergence and diffusion.

Intra-urban spatial distribution of Malaria

Georganos S, Brousse O, Dujardin S, Linard C, Casey D, Milliones M, Parmentier B, van Lipzig NPM, Demuzere M, Grippa T, Vanhuysse S, Mboga N, Andreo V, Snow RW, Lennert M. 2020. Modelling and mapping the intra-urban spatial distribution of Plasmodium falciparum parasite rate using very-high-resolution satellite derived indicators. International Journal of Health Geographics 19:38. DOI: 10.1186/s12942-020-00232-2.

The rapid and often uncontrolled rural–urban migration in Sub-Saharan Africa is transforming urban landscapes expected to accommodate 50% of Africa’s population by 2030. Malaria is thus increasingly affecting the urban population, while socio-economic inequalities within the urban settings are intensified. Here, land-use, land-cover and population information gained from very-high-resolution satellite images are used to model the spatial distribution of urban malaria prevalence across large spatial extents for two Sub-Saharan African cities, Kampala and Dar es Salaam. As a result, populations living in informal settlements show higher malaria prevalence compared to those in planned residential neighbourhoods. This is due to (i) increased human exposure to vectors, (ii) increased vector density and (iii) a reduced capacity to cope with malaria burden. Since informal settlements are rapidly expanding every year, this emphasizes the need for systematic and consistent malaria surveys in such areas. The study further emphasizes the importance of remote sensing as an epidemiological tool.

Perceptions of and responses to coastal erosion risks

de Longueville F, Hountondji Y-C, Assogba L, Henry S, Ozer P. 2020. Perceptions of and responses to coastal erosion risks: The case of Cotonou in Benin. International Journal of Disaster Risk Reduction 51:101882. DOI: 10.1016/j.ijdrr.2020.101882.

The coastal area of Cotonou, Benin, is highly urbanised and clearly a risk-prone zone as affected by a fast erosion for several decades. The speed of coastal erosion over the last two decades was impressive (115 m between 2002 and 2013!) and destroyed several hundred houses. This study identifies the population at risk and analyses the perceptions of people who experience and those who manage coastal erosion risk, as well as the responses adopted. With the recent stabilisation of the coastline, the national authorities manage the “hazard” component of the risk. However, the majority of the population is not serene, especially poorer people that cannot afford to move away from the coast or fishermen that depend on the sea to make their living. Additionally, the anthropogenic stress linked to evictions through authorities gradually replaced the stress to be engulfed by the sea. Thus, the “vulnerability” component of the risk is not yet resolved.

“Slum” Mapping

Thomson DR, Kuffer M, Boo G, Hati B, Grippa T, Elsey H, Linard C, Mahabir R, Kyobutungi C, Maviti J, Mwaniki D, Ndugwa R, Makau J, Sliuzas R, Cheruiyot S, Nyambuga K, Mboga N, Kimani NW, de Albuquerque JP, Kabaria C. 2020. Need for an Integrated Deprived Area “Slum” Mapping System (IDEAMAPS) in Low- and Middle-Income Countries (LMICs). Social Sciences 9:80. DOI: 10.3390/socsci9050080.

Ninety percent of the people added to the planet over the next 30 years will live in African and Asian cities, and a large portion of these populations will reside in deprived neighborhoods defined by slum conditions, informal settlement, or inadequate housing. Four current approaches to neighborhood deprivation mapping are largely siloed, and each fall short of producing accurate, timely, and comparable maps that reflect local contexts. The authors summarize common areas of understanding, and present a set of requirements and a framework to produce routine, accurate maps of deprived urban areas that can be used by local‐to‐international stakeholders for advocacy, planning, and decision‐making across Low‐ and Middle‐Income Countries. They suggest that machine learning models be extended to incorporate social area‐level covariates and regular contributions of up‐to‐date and context‐relevant field‐based classification of deprived urban areas.

Climate change perceptions and migration in West Africa

De Longueville F, Ozer P, Gemenne F, Henry S, Mertz O, Nielsen JØ. 2020. Comparing climate change perceptions and meteorological data in rural West Africa to improve the understanding of household decisions to migrate. Climatic Change. DOI: 10.1007/s10584-020-02704-7.

West African populations largely depend on agriculture. Climate change, increasing rainfall variability and drought may thus have negative impacts on crop production and livestock and increase poverty and food insecurity. One adaptation strategy is migration. This study, composed of a literature review and an empirical study, highlights the importance of taking into account people’s perceptions of climate change as it affects their adaptation responses. These do not always match with actual rainfall data. To improve the understanding of the decision to migrate on a household level, it is recommended to jointly consider data on climate as well as on the perception of climate variability. This approach definitely requires interdisciplinary research!

Urban Changes of Beijing

Sorichetta A, Nghiem SV, Masetti M, Linard C, Richter A. 2020. Transformative Urban Changes of Beijing in the Decade of the 2000s. Remote Sensing 12:652. DOI: 10.3390/rs12040652.

The rapid growth of urban populations and the associated infrastructure contribute to a large part to greenhouse gases from power generation, industry, transportation, and consumption. The rapid economic growth, the exodus from rural to urban areas, and the associated extreme urban development that occurred in China in the decade of the 2000s have severely impacted the environment in Beijing, its vicinity, and beyond. This article presents an innovative approach for assessing mega-urban changes and their impact on the environment based on the use of decadal QuikSCAT (QSCAT) satellite data, acquired globally by the SeaWinds scatterometer over that period. Here, the corresponding tropospheric nitrogen dioxide (NO2) column densities are used as a proxy. Results reveal a threefold increase of the yearly tropospheric NO2 column density within the Beijing infrastructure-based urban area extent in 2009, which had quadrupled since 2000.

Mobile Phone Data for Urban Climate Change Adaptation

Dujardin S, Jacques D, Steele J, Linard C. 2020. Mobile Phone Data for Urban Climate Change Adaptation: Reviewing Applications, Opportunities and Key Challenges. Sustainability 12:1501. DOI: 10.3390/su12041501.

Climate change places cities at increasing risk and poses a serious challenge for adaptation. Novel sources of data combined with data-driven logics and advanced spatial modelling techniques would have the potential for transformative change applied in urban planning. However, little practical guidance exists on the opportunities offered by mobile phone data for enhancing adaptive capacities in urban areas. This paper explores the opportunities offered by such digital information for providing spatially-explicit assessments of urban vulnerability, and shows the ways these can help developing more dynamic strategies and tools for urban planning and disaster risk management. Finally, building upon the limitations of mobile phone data analysis, it discusses the key urban governance challenges that need to be addressed for supporting the emergence of transformative change in current planning frameworks.

Intrinsically Disordered Proteins

Michaux C, Mignon J, Perpète E. 2020. Promising Drug Design Strategies : Intrinsically Disordered Proteins. Annals of Advanced Biomedical Sciences 3:000152. LINK

In contrast to the classical paradigm “one sequence - one structure - one function” that a given protein sequence corresponds to a well-defined three-dimensional (3D) structure and an associated function, it was discovered in the 1990s that an increasing number of proteins can be functional in the absence of a stable 3D-structure [1]. This new concept, the “disorder-function paradigm”, assumes that an intrinsically flexible protein may have several structures and consequently various functions. Intrinsically Disordered Proteins constitute a unique class of proteins with crucial biological functions. his mini-review gives an overview on studies that highlight their intrinsic properties and binding mechanisms.

Developmental toxicology of a medicinal plant

Nguyen TH, Nguyen P-D, Quetin-Leclercq J, Muller M, Ly Huong DT, Pham HT, Kestemont P. 2020. Developmental toxicity of Clerodendrum cyrtophyllum turcz ethanol extract in zebrafish embryo. Journal of Ethnopharmacology:113538. DOI: 10.1016/j.jep.2020.113538.

Clerodendrum cyrtophyllum (Lamiaceae), a medicinal plant, is widely used in traditional medicine of many Asian countries for the treatment of colds, high fever, migraines, hypertension, etc. Its therapeutic and pharmacological properties have recently been reported, but no studies on potential toxicity on reproductive tissues are known. This study investigates the developmental toxicity induced by an ethanol extract (EE) in the zebrafish model. Results demonstrate that EE caused developmental toxicity to zebrafish embryos/larvae and provide evidence of toxicity of EE to embryo stages. Thus, this extract could also have potential risks for the development of human embryos, and caution should be taken when consumed during pregnancy.

Chronic effects of an insecticide on Nile Tilapia

Guedegba NL, Toko II, Ben Ammar I, François L, Oreins N, Palluel O, Mandiki SNM, Jauniaux T, Porcher J-M, Scippo M-L, Kestemont P. 2020. Chronic effects of a binary insecticide Acer 35EC on Nile tilapia Oreochromis niloticus through a multi-biomarker approach. Chemosphere:128530. DOI: 10.1016/j.chemosphere.2020.128530.

Acer 35EC is a widely used insecticide in pest control in many West African countries, particularly in the cotton culture in north Benin. This study used a multi-biomarker approach to investigate possible chronic effects of Acer 35EC on Nile tilapia Oreochromis niloticus. Results show that even at doses below the environmental concentrations, Acer 35EC impairs the physiology and health status of fish. This binary insecticide affects many systems including immune, reproductive and nervous systems. Especially affected were females, with negative effects for steroidogenesis and gametogenesis, testosterone levels and oocyte growth.

Delayed effects of an endocrine disruptor

Voisin AS, Ulloa VS, Stockwell P, Chatterjee A, Silvestre F. 2020. Genome-wide DNA methylation of the liver reveals delayed effects of early-life exposure to 17-α-ethinylestradiol in the self-fertilizing mangrove rivulus. Preprints. DOI: 10.22541/au.159310037.71467325.

Early-life exposure to environmental stressors, encountered during the sensitive period of embryogenesis or in juveniles, can be critical in shaping the long-term control of tissue physiology and homeostasis. Identifying the molecular mechanisms is important to understand the long-term effects of toxicants in humans and wildlife. DNA methylation could mediate long-term effects of sub-toxic developmental exposure to xenobiotics and play a role in the etiology of diseases (cancer, obesity, cardiovascular disease, diabetes, hypertension, and neurodegenerative disorders), acting as a long-term memory of past exposures. This study exposed hatchlings of an isogenic lineage of the self-fertilizing fish mangrove rivulus to an EDC, an endocrine disrupting chemical (17-α-ethinylestradiol, a synthetic estrogen, that is used in oral contraceptive pills and released into the environment). After a recovery period, reduced representation bisulfite sequencing (RRBS) was performed on the liver. Gene ontology analysis revealed networks involved in lipid metabolism, cellular processes, connective tissue function, molecular transport and inflammation. Results provide further evidence on the capacity of EDCs to alter the methylome and shows that these changes can be apparent several months after the exposure, supporting the hypothesis of possible long-term modulation of gene expression through epigenetics.

Pesticides in freshwater food webs

Zhao Q, De Laender F, Van den Brink PJ. 2020. Community composition modifies direct and indirect effects of pesticides in freshwater food webs. Science of The Total Environment 739:139531. DOI: 10.1016/j.scitotenv.2020.139531.

For environmental risk assessment, the effects of pesticides on aquatic ecosystems are often assessed based on single species tests, disregarding the potential influence of community composition. Here, the influence of changing the horizontal (the number of species within trophic levels) and vertical composition (number of trophic levels) on the ecological effects of two pesticides is investigated, which target producers and herbivores, respectively. The study shows that changing horizontal composition can both increase and decrease the effects of the selected pesticides, while changing vertical composition by adding number of trophic levels always increased these effects. Therefore, single species sensitivity will not always represent a worst-case estimate of ecological effects. Protecting the most sensitive species may not ensure protection of ecosystems.

Neurotoxins & mangrove rivulus brain

Carion A, Markey A, Hétru J, Carpentier C, Suarez-Ulloa V, Denoël M, Earley RL, Silvestre F. 2020. Behavior and gene expression in the brain of adult self-fertilizing mangrove rivulus fish (Kryptolebias marmoratus) after early life exposure to the neurotoxin β-N-methylamino-L-alanine (BMAA). NeuroToxicology. DOI: 10.1016/j.neuro.2020.04.007.

BMAA, a neurotoxin naturally produced by cyanobacteria, diatoms and dinoflagellates, is a serious environmental and health threat, especially during acute blooms, which are becoming more frequent. This neurotoxin is implicated in several neurodegenerative diseases in humans through contaminated water or food consumption. This study investigates the delayed effects of a neurotoxic compound and their underlying mechanisms. The mangrove rivulus fish used as model species is able to self-fertilize and to produce isogenic lineages permitting explicit examination of environmental effects on the phenotype by reducing the genetic “noise “in the experiment. No delayed effects of BMAA on growth, reproduction, boldness and aggressiveness behavioural traits were observed. But the study revealed that BMAA can have long-lasting effects on the brain that are suspected to affect phenotypic traits with aging.

Line shape parameters for the H2O-N2 collision system

Vispoel B, Cavalcanti JH, Paige ET, Gamache RR. 2020. Vibrational dependence, temperature dependence, and prediction of line shape parameters for the H2O-N2 collision system. Journal of Quantitative Spectroscopy and Radiative Transfer 253:107030. DOI: 10.1016/j.jqsrt.2020.107030.

Water vapor can be seen throughout the universe (planets, comets, asteroids, dwarfs and cold stars). It is a major absorber of infrared radiation. On Earth, water vapor dominates the infrared spectrum. The study and modeling of atmospheric spectra requires a precise knowledge of spectroscopic data.
In a recent work, Vispoel et al. [JQSRT 228, 79(2019)] optimized the intermolecular potential used in the Modified Complex Robert-Bonamy (MCRB) formalism for the H2O-N2 molecular system, and made calculations for the rotation and ν2 bands. In this work, calculations were performed for 7272 transitions of 11 bands (0-4 vibrational quanta exchanged in the ν1, ν2 and ν3 bands) at 13 temperatures between 200 and 3000K. The temperature dependence was determined using the Gamache-Vispoel model [JQSRT 217, 440(2018)].
The large quantity of data allowed the development of a routine that can predict the half-width, line shift, and their temperature dependence for transitions not yet studied. The algorithm yields to line shape parameters with much smaller uncertainty than other methods (ad hoc polynomials or J” averaged values). A line file based on the 2020 update to the HITRAN2016 water vapor line file was created with N2 as the broadening species. These data are useful for combustion studies and as a first step to determine air-broadening for the HITRAN and GEISA databases.

Unified study of multiple stressors

Orr JA, Vinebrooke RD, Jackson MC, Kroeker KJ, Kordas RL, Mantyka-Pringle C, Van den Brink PJ, De Laender F, Stoks R, Holmstrup M, Matthaei CD, Monk WA, Penk MR, Leuzinger S, Schäfer RB, Piggott JJ. 2020. Towards a unified study of multiple stressors: divisions and common goals across research disciplines. Proceedings of the Royal Society B: Biological Sciences 287:20200421. DOI: 10.1098/rspb.2020.0421.

Anthropogenic environmental changes, or ‘stressors’, increasingly threaten biodiversity and ecosystem functioning worldwide. Multiple-stressor research is a rapidly expanding field of science that seeks to understand and ultimately predict the interactions between stressors. Reviews and meta-analyses of the primary scientific literature have largely been specific to either freshwater, marine or terrestrial ecology, or ecotoxicology. This cross-disciplinary study reviews the state of knowledge within and among these disciplines to highlight commonality and division in multiple-stressor research. The review further uses quantitative bibliometric analysis to identify the division between disciplines and link previously disconnected research communities. Towards a unified research framework, the shared goal of increased realism through both ecological and temporal complexity is discussed, with the overarching aim of improving predictive power.

Oxidative stress in aquatic organisms

Silvestre F. Signaling pathways of oxidative stress in aquatic organisms exposed to xenobiotics. Journal of Experimental Zoology Part A: Ecological and Integrative Physiology n/a. DOI: 10.1002/jez.2356.

Oxidative stress is frequently generated in cells of organisms exposed to environmental pollutants. The production of reactive oxygen species (ROS) can have either adaptive or maladaptive consequences for the organism as well as for the entire population. This review shows that important pathways described in mammals are also activated in aquatic species in response to a variety of xenobiotics. There also exist crosstalks between these pathways, which together activate a complex cellular antioxidative machinery in response to different stressors. Efforts should be made to extend the number of studied species and better characterize the organ‐dependency and age‐dependency of the responses. However, the huge number and variety of chemicals present in the environment makes the task difficult. Deciphering these key pathways can help to understand the mode of action of pollutants and consequently help to assess the environmental risk in aquatic ecosystems.

Chemical stress & freshwater invertebrates

Van den Berg SJP, Rendal C, Focks A, Butler E, Peeters ETHM, De Laender F, Van den Brink PJ. 2020. Potential impact of chemical stress on freshwater invertebrates: A sensitivity assessment on continental and national scale based on distribution patterns, biological traits, and relatedness. Science of The Total Environment 731:139150. DOI: 10.1016/j.scitotenv.2020.139150.

Current chemical risk assessment approaches rely on a standard suite of test species to assess toxicity to environmental species. However, these are usually not representative of all species present in ecosystems with regards to their sensitivity to stressors. Here, predictive sensitivity models were developed by combining species-specific information on acute chemical sensitivity (LC50 and EC50), traits, and taxonomic relatedness. These models were applied at two spatial scales to reveal spatial differences in the sensitivity of species assemblages towards two chemical modes of action (MOA): narcosis and acetylcholinesterase (AChE) inhibition. Hotspots of species sensitive to chemical stressors were identified at two spatial scales. Crucial technological advances are required for the successful application of the proposed methodology to invertebrate scenarios, which remain underrepresented in global conservation priorities.

Spectroscopy to measure temperature dependence

Leonis S, Lepère M. 2020. N2-collisional broadening coefficients of lines in the ν2 band of chloromethane from low to room temperatures. Journal of Molecular Spectroscopy 369:111269. DOI: 10.1016/j.jms.2020.111269.

To understand climate change, it is necessary to understand and quantify the evolution of pollutants in our atmosphere, such as the chloromethane. Accurate spectroscopic parameters of such greenhouse gases, and in particular, their collisional broadening coefficients help us to characterize our atmosphere. This study measures the N2-broadening coefficients in the band of chloromethane at low and room temperatures with the help of high-resolution diode-laser spectroscopy. Experimental line profiles were fitted with different line shape models.

Anti–inflammatory and antioxidant for Zebrafish

Nguyen TH, Le HD, Kim TNT, The HP, Nguyen TM, Cornet V, Lambert J, Kestemont P. 2020. Anti–Inflammatory and Antioxidant Properties of the Ethanol Extract of Clerodendrum Cyrtophyllum Turcz in Copper Sulfate-Induced Inflammation in Zebrafish. Antioxidants 9:192. DOI: 10.3390/antiox9030192.

Oxidative stress and inflammation contribute to the pathogenesis of many chronic diseases. This study tests the plant Clerodendrum cyrthophyllum (Verbenaceae) for its antioxidant and/or anti‐inflammatory activities, which could provide a useful treatment of pathologies. The plant is used in Vietnamese traditional medicine against inflammation of the throat, rheumatic arthritis, etc. This study tested its antioxidant and anti‐inflammatory effects on zebrafish. Inflammation was induced through an oxidative stress reaction to copper (CuSO4) exposure. Preceding treatment with an ethanol extract of C. cyrtophyllum leaves showed protective activity against oxidative stress as measured via fluorescent intensity. Further, genes related to inflammatory processes were downregulated by C. cyrtophyllum, suggesting its usefulness to treat inflammatory diseases.

Anti-inflammatory properties of Clerodendrum cyrtophyllum

Nguyen TH, Nachtergael A, Nguyen TM, Cornet V, Duez P, Muller M, Ly Huong DT, Kestemont P. 2020. Anti-inflammatory properties of the ethanol extract from Clerodendrum cyrtophyllum Turcz based on in vitro and in vivo studies. Journal of Ethnopharmacology 254:112739. DOI: 10.1016/j.jep.2020.112739.

Another test of the anti-inflammatory properties of the Verbenaceae plant Clerodendrum cyrtophyllum, again with zebrafish as in vitro and in vivo model. Colorimetric methods and HPTLC revealed high phenolic and flavonoid contents in the ethanol extract of the plant. The ethanol extract reduced the expression of several inflammatory genes and increase the expression of an anti-inflammatory cytokine gene. The results confirm the use in traditional medicine of this plant in Asia to treat inflammations and proposes the raw ethanol extract of the leaves as potential treatment.

Biomimetic hybrid membranes

Molina BG, Lopes-Rodrigues M, Estrany F, Michaux C, Perpète EA, Armelin E, Alemán C. 2020. Free-standing flexible and biomimetic hybrid membranes for ions and ATP transport. Journal of Membrane Science 601:117931. DOI: 10.1016/j.memsci.2020.117931.

Biomimetics takes advantage of the natural structures found in biological systems, permitting a nanoscopic development of functional materials. Many of such nanomaterials based on proteins (e.g. filtration devices, nanosensors) usually require nanoscopic pathways for the passage of ions and small molecules. Porins, i.e. outer membrane proteins (OMPs) found in gram-negative bacteria and mitochondria, can naturally form β-barrel channels. They act as gates of the cell membrane. Here, for the first time, a free standing and conducting polymeric membrane with porin protein immobilized has been developed and proved to be efficient for transport of ATP and NaCl. Thus, the hybrid system obtained by combining synthetic polymers and porin proteins is well-suited for the development of flexible membrane biosensors with fully functional transmembrane ion channels. The new platform is fully free-standing and flexible and can be applied in many biomedical technologies, opening new frontiers for the future development of high-throughput screening assays.

2019

People and Pixels

Kugler TA, Grace K, Wrathall DJ, de Sherbinin A, Van Riper D, Aubrecht C, Comer D, Adamo SB, Cervone G, Engstrom R, Hultquist C, Gaughan AE, Linard C, Moran E, Stevens F, Tatem AJ, Tellman B, Van Den Hoek J. 2019. People and Pixels 20 years later: the current data landscape and research trends blending population and environmental data. Population and Environment 41:209–234. DOI: 10.1007/s11111-019-00326-5

In 1998, the National Research Council published People and Pixels: Linking Remote Sensing and Social Science. The volume focused on emerging research linking changes in human populations and land use/land cover to shed light on issues of sustainability, human livelihoods, and conservation, and led to practical innovations in agricultural planning, hazard impact analysis, and drought monitoring. Since then, new research opportunities have emerged thanks to the growing variety of remotely sensed data sources, an increasing array of georeferenced social science data, including data from mobile devices, and access to powerful computation cyberinfrastructure. This article outlines the key extensions of the People and Pixels foundation since 1998 and highlights several breakthroughs in research on human–environment interactions. Pressing research problems are identified—disaster, famine, drought, war, poverty, climate change—and it is explored how interdisciplinary approaches integrating people and pixels are being used to address them.

Wealth maps of cities

Georganos S, Gadiaga AN, Linard C, Grippa T, Vanhuysse S, Mboga N, Wolff E, Dujardin S, Lennert M. 2019. Modelling the Wealth Index of Demographic and Health Surveys within Cities Using Very High-Resolution Remotely Sensed Information. Remote Sensing 11:2543. DOI: 10.3390/rs11212543.

To address the United Nations Sustainable Development Goals (SDGs), a systematic and precise understanding of urban socio-economic spatial inequalities in developing regions is needed. However, exhaustive census information is often outdated, unreliable or inaccessible. Geolocated surveys such as the Demographic and Health Surveys (DHS) may provide alternative solutions but suffer from the lack of very high-resolution (VHR) predictor variables. This study couples satellite-derived VHR land-use/land-cover (LULC) datasets with the DHS Wealth Index (WI), a robust household wealth indicator, in order to provide city-scale wealth maps. Modelling approaches using a random forest regressor as the underlying algorithm at several geographic administrative scales are validated against an exhaustive census database of Dakar, Senegal. Results show that the WI was modelled to a satisfactory degree when compared against census data even at very fine resolutions. These findings might assist local authorities and stakeholders in rigorous evidence-based decision making and facilitate the allocation of resources towards the most disadvantaged populations.

Pollen allergy & green space

Aerts R, Stas M, Vanlessen N, Hendrickx M, Bruffaerts N, Hoebeke L, Dendoncker N, Dujardin S, Saenen ND, Van Nieuwenhuyse A, Aerts J-M, Van Orshoven J, Nawrot TS, Somers B. 2019. Residential green space and seasonal distress in a cohort of tree pollen allergy patients. International Journal of Hygiene and Environmental Health. DOI: 10.1016/j.ijheh.2019.10.004.

Residential green space may promote physical activity and thus, reduce stress and improve human health. Conversely, such green space may increase stress by emitting aeroallergens and exacerbating allergic disease. This study investigates seasonal distress in a panel of 88 patients allergic to tree pollen. In general, short-term distress decreased with increasing residential green space within 1 km distance. However, allergy patients suffered from higher distress than the general population. The perceived presence of allergenic tree species was associated with higher distress, which modulates the protective effect of residential green space against distress during the airborne tree pollen season.

Ordering space & changing climate

Dujardin S, Dendoncker N. 2019. Ordering Space in a Changing Climate: A Relational Analysis of Planning Practices in Bohol, Philippines. Planning Theory & Practice 0:1–22. DOI: 10.1080/14649357.2019.1672773

Approaches to planning for climate change deal primarily with physical planning mechanisms while social planning processes are hardly considered. This paper draws upon the analytical lens of modes of ordering to trace the network of relationships taking place in the preparation and implementation of municipal land use plans within the coastal municipalities of Bohol, Philippines. Results highlight how planning’s dominant mode of ordering tends to address disaster risk areas by focusing primarily upon the physical characteristics of space and infrastructures. Some networks, however, recognize place-based knowledge from the most vulnerable communities. Evidence of some amendments to planning processes are provided, so that approaches integrating the agency of both human and non-human actors can be brought effectively into planning frameworks.

Malaria risk & satellite imagery

Solano-Villarreal E, Valdivia W, Pearcy M, Linard C, Pasapera-Gonzales J, Moreno-Gutierrez D, Lejeune P, Llanos-Cuentas A, Speybroeck N, Hayette M-P, Rosas-Aguirre A. 2019. Malaria risk assessment and mapping using satellite imagery and boosted regression trees in the Peruvian Amazon. Scientific Reports 9:1–12. DOI: 10.1038/s41598-019-51564-4.

In spite of the investment in control and prevention allocated by the Peruvian government over the last decades, malaria due to both Plasmodium vivax and P. falciparum remains a significant public health issue in the country. This is the first study to assess the risk of co-endemic Malaria pathogen transmission in the Peruvian Amazon using boosted regression tree (BRT) models based on social and environmental predictors derived from satellite imagery and data. Cumulative rainfall, population density and time to populated villages were consistently the top three predictors for both P. vivax and P. falciparum incidence. Maps created using the BRT models characterize the spatial distribution of the malaria incidence and should contribute to malaria-related decision making in the investigated Amazon region.

Birch pollen in Belgium

Verstraeten WW, Dujardin S, Hoebeke L, Bruffaerts N, Kouznetsov R, Dendoncker N, Hamdi R, Linard C, Hendrickx M, Sofiev M, Delcloo AW. 2019. Spatio-temporal monitoring and modelling of birch pollen levels in Belgium. Aerobiologia. DOI: 10.1007/s10453-019-09607-w

About 10% of the Belgian population suffer from allergies due to birch pollen. However, real-time and detailed spatial information on forthcoming pollen exposure episodes that would allow preventive actions is lacking. This study evaluates birch pollen levels near the surface with SILAM (System for Integrated modeLling of Atmospheric coMposition) simulations based on meteorological data and areal fraction maps of birch trees. The correlation (R2) between SILAM modelled and observed time series of daily birch pollen levels was up to ~ 50%. The 5-day averaged pollen concentrations from SILAM have R2 values between 0.49 and 0.84 at the pollen stations included in this study.

Comparison of methods to disaggregate human population

Stevens FR, Gaughan AE, Nieves JJ, King A, Sorichetta A, Linard C, Tatem AJ. 2019. Comparisons of two global built area land cover datasets in methods to disaggregate human population in eleven countries from the global South. International Journal of Digital Earth 0:1–23. DOI: 10.1080/17538947.2019.1633424

Mapping built land cover at unprecedented detail has been facilitated by increasing availability of global high-resolution imagery and image processing methods. These advances in urban feature extraction and built-area detection can refine the mapping of human population densities, especially in lower income countries where rapid urbanization and changing population is accompanied by frequently out-of-date or inaccurate census data. Here, two methods were tested, that include simple, areal weighting and more complex statistical models with other ancillary information. Outcomes were assessed across eleven countries, representing different world regions varying in population densities, types of built infrastructure, and environmental characteristics. For seven of them, a Random Forest-based, machine learning approach outperforms simple, binary dasymetric disaggregation into remotely-sensed built areas.

Geographical Random Forest (GRF) to estimate population

Georganos S, Grippa T, Gadiaga A, Vanhuysse S, Kalogirou S, Lennert M, Linard C. 2019. An Application of Geographical Random Forests for Population Estimation in Dakar, Senegal using Very-High-Resolution Satellite Imagery. In: 2019 Joint Urban Remote Sensing Event (JURSE). 1–4. DOI: 10.1109/JURSE.2019.8809049

This paper studies a local implementation of Random Forest (RF), named Geographical Random Forest (GRF) to predict population density with Very-High-Resolution Remote Sensing (VHHRS) data. As an independent variable, population density at the neighbourhood level was used from the 2013 census of Dakar. The proportions of three different built-up types in each neighbourhood derived from a VHHRS land cover classification served as explanatory features. The results show, that by using an appropriate geographic scale to calibrate GRF, prediction accuracy can be maximised due to the incorporation of spatial heterogeneity in the estimates. Additionally, since GRF is an ensemble of local sub-models, the results can be mapped, highlighting local model performance and other interesting spatial variations. Consequently, GRF is suggested as valuable exploratory and explanatory technique to model remotely-sensed spatially heterogeneous relationships.

Extending Data for Urban Health Decision-Making

Thomson DR, Linard C, Vanhuysse S, Steele JE, Shimoni M, Siri J, Caiaffa WT, Rosenberg M, Wolff E, Grippa T, Georganos S, Elsey H. 2019. Extending Data for Urban Health Decision-Making: a Menu of New and Potential Neighborhood-Level Health Determinants Datasets in LMICs. Journal of Urban Health. DOI: 10.1007/s11524-019-00363-3.

This paper aims at the extension of awareness among urban health decision-makers and data scientists about existing and potential datasets that can support urban health decision-making. It summarizes sources of neighbourhood-level data and introduces two case studies that demonstrate the need for neighbourhood-level indicator datasets for decision-making. It further reviews indicators at neighbourhood-level that determine health and urban poverty. This allowed the generation of a list containing important neighbourhood-level datasets, that can be processed by data scientists for health decision-makers. Ideally, these should be open source and freely available.

A public health threat due to illegal import?

Jansen W, Linard C, Noll M, Nöckler K, Al Dahouk S. 2019. Brucella-positive raw milk cheese sold on the inner European market: A public health threat due to illegal import? Food Control 100:130–137. DOI: 10.1016/j.foodcont.2019.01.022.

Brucellosis is a very common zoonosis caused by Gram-negative bacteria Brucella sp. Humans are usually infected by consuming unpasteurized milk or dairy products in or from endemic regions. Despite successful eradication from livestock in EU Member States, human infections occur annually. This study found Brucella-DNA in 20% of 200 cheese samples from endemic countries that were sold at weekly markets, in supermarkets and by delis in Berlin (Germany). Clustered positive samples at certain vendors suggest organized trade of illegal imports undermining EU food safety standards. A few cheeses investigated were produced from raw milk with short ripening periods that Brucella might survive.

Diseases & land use

Vanwambeke SO, Linard C, Gilbert M. 2019. Emerging challenges of infectious diseases as a feature of land systems. Current Opinion in Environmental Sustainability 38:31–36. DOI: 10.1016/j.cosust.2019.05.005.

The association of infectious diseases to the environment, and in particular land use, has regained interest in the late 20th century in relation to global environmental change. Four major challenges are identified: First, the multifactorial determinants of the complex ecological systems of infectious diseases should be better acknowledged. Second, new challenges appear in urban areas in relation to their dynamics. Third, livestock raising, as a component of land systems, creates specific types of ecological interfaces. Fourth, tensions discussed in the land use community regarding conservation must account for issues related to the health of human, livestock and wildlife.

Does climate influence migration?

De Longueville F, Zhu Y, Henry S. 2019. Direct and indirect impacts of environmental factors on migration in Burkina Faso: application of structural equation modelling. Population and Environment. DOI: 10.1007/s11111-019-00320-x.

Does drought in Africa cause massive migration to Europe? For 20 years now, this question intrigues Sabine Henry (Geography). She published the first empirical evidence for the impact of droughts on migration in 2004, a highly cited publication. Today, she and Florence De Longeville remain pioneers in distinguishing the direct effects of the environment on migration from indirect effects that reduce the socio-economic level of households. This was also one of the first proofs of the concept of “trapped populations” as defined by Black et al. (2011), communities, that too poor to migrate and are thus extremely vulnerable to climate change. The result of a successful collaboration with the London School of Economy and the University of Cambridge, this study helps to develop more appropriate climate change adaptation policies.

MR vs. VHR

Grippa T, Linard C, Lennert M, Georganos S, Mboga N, Vanhuysse S, Gadiaga A, Wolff E. 2019. Improving Urban Population Distribution Models with Very-High Resolution Satellite Information. Data 4:13. DOI: 10.3390/data4010013.

Freely available medium resolution (MR) satellite information is useful in dasymetric mapping, but suffers from important limitations at the intra-urban level. This paper finds that very-high resolution (VHR) data increase the accuracy of the dasymetric mapping procedure by ~13%.  However, their acquisition and processing costs hinders their applicability for large-scale population mapping in Africa. This paper compares data sets with different spatial and thematic resolutions to disaggregate population counts into 1-hectare grid cells.

Spread of mosquitoes, carrier of deseases

Kraemer MUG, Reiner RC, Brady OJ, ..., Linard C, .... 2019. Past and future spread of the arbovirus vectors Aedes aegypti and Aedes albopictus. Nature Microbiology:1. DOI: 10.1038/s41564-019-0376-y.

Tropical viral diseases (e.g. dengue, yellow fever, Zika) expand globally as do their key vectors, two mosquito species: Aedes aegypti & Aedes albopictus. Their distribution is largely driven by both human movement and the presence of suitable climate. Using statistical mapping techniques, actual processes are described and future distributions predicted for both species in relation to accelerating urbanization, connectivity and climate change. These maps and predictions offer an opportunity to strategically target surveillance and control programmes and thereby augment efforts to reduce arbovirus burden in human populations globally.

Patterns of urban growth in SSA

Wolff E, Grippa T, Forget Y, Georganos S, Vanhuysse S, Shimoni M, Linard C. 2019. Diversity of urban growth patterns in Sub-Saharan Africa in the 1960–2010 period. African Geographical Review 0:1–13. DOI: 10.1080/19376812.2019.1579656.

Since 1960, urbanization in Sub-Saharan Africa (SSA) has been rapid. While consistent demographic statistics now exist on urban population growth rates, these data have not been fully exploited to improve our understanding of the evolution of urbanization at the continental scale. We investigate urban change between 1950 and 2010 across SSA using cluster analyses performed on three complementary aspects: the evolution of urban growth rates, primacy, and the densification of the urban mesh. Results show that SSA countries followed diverse urbanization trajectories over the last 60 years and are currently unevenly distributed along the urban transition model.

Climate zones & urban health

Brousse O, Georganos S, Demuzere M, Vanhuysse S, Wouters H, Wolff E, Linard C, van Lipzig NP-M, Dujardin S. 2019. Using Local Climate Zones in Sub-Saharan Africa to tackle urban health issues. Urban Climate 27:227–242. DOI: 10.1016/j.uclim.2018.12.004.

This study gives an example on how to link models of urban climate with climate-related health issues in Sub-Saharan Africa. Universal classifications of Local Climate Zones are combined with very high resolution satellite imagery and can then be used to create a simple urban canopy model over two cities: Kampala (Uganda) and Dakar (Senegal). Such models can help to analyze health issues, such as malaria risk, in highly dynamic environments.

Georganos S, Grippa T, Gadiaga AN, Linard C, Lennert M, Vanhuysse S, Mboga NO, Wolff E, Kalogirou S. 2019. Geographical Random Forests: A Spatial Extension of the Random Forest Algorithm to Address Spatial Heterogeneity in Remote Sensing and Population Modelling. Geocarto International 0:1–12. DOI: 10.1080/10106049.2019.1595177.

Characterising plant channels

Lopes‐Rodrigues M, Matagne A, Zanuy D, Alemán C, Perpète EA, Michaux C. Structural and functional characterization of Solanum tuberosum VDAC36. Proteins: Structure, Function, and Bioinformatics n/a. DOI: 10.1002/prot.25861.

The voltage‐dependent anion channel (VDAC) protein family plays a central role in all eukaryotic cells. It forms water‐filled channels in the mitochondria outer membrane and diffuses essential metabolites such as NADH and ATP. Compared with their mammalian homologues, little is known about the structural and functional properties of plant VDACs. Here, one of the two VDACs isoforms of Solanum tuberosum, stVDAC36, has been successfully overexpressed and refolded by a method, that has been established by the CPB lab of UNamur. This is demonstrated by the information on its secondary and tertiary structure gathered from circular dichroism and intrinsic fluorescence. Cross‐linking and molecular modelling studies have evidenced the presence of dimers and tetramers, and they suggest the formation of an intermolecular disulphide bond between two stVDAC36 monomers. The pore‐forming activity was also assessed by liposome swelling assays, indicating a typical pore diameter between 2.0 and 2.7 nm. Finally, insights about the ATP binding inside the pore are given by docking studies and electrostatic calculations.

Line shift coefficients of methane

Vispoel B, Lepère M. 2019. N2-collisional shift coefficients of lines in the ν3 band of methane from low to high temperatures. Journal of Quantitative Spectroscopy and Radiative Transfer 239:106654. DOI: 10.1016/j.jqsrt.2019.106654

Though methane is a minor constituent of the Earth’s atmosphere, its effect on climate and atmospheric chemistry is important. Methane is also present in atmospheres of several planets (e.g. Mars) and stellar objects and could indicate the presence of life. Retrievals of atmospheric spectra are very sensitive to the spectroscopic parameters, especially to half-width and line shifts that are hardly known. This study measures line shift coefficients of methane perturbed by nitrogen using a dual beam tuneable diode-laser spectrometer of high resolution. The measurements were performed from low (123 K) to high (598 K) temperatures. This large temperature range allowed to study the temperature dependence of the collisional line shift coefficients using 2 empirical laws (the power law and the linear law) as well as the new physics based double power law (DPL). The results show that the DPL reproduces more accurately the evolution of the line shift with the temperature. An accurate knowledge of the temperature dependence of line shape parameters is crucial for the remote sensing of the Earth's or planetary atmospheres.

Temperature dependence of line shape parameters

Stolarczyk N, Thibault F, Cybulski H, Jóźwiak H, Kowzan G, Vispoel B, Gordon IE, Rothman LS, Gamache RR, Wcislo P. 2019. Evaluation of different parameterizations of temperature dependences of the line-shape parameters based on ab initio calculations: case study for the HITRAN database. Journal of Quantitative Spectroscopy and Radiative Transfer:106676. DOI: 10.1016/j.jqsrt.2019.106676.

The knowledge of accurate molecular spectroscopic parameters is essential to interpret and model spectra of terrestrial and planetary atmospheres. These parameters need to be known with a high precision as well as their evolution with temperature (for instance the temperature on Uranus is 55K while hot Jupiter planets can reach 1000 – 2500K). Within all the needed data, the half-width and line shift are crucial parameters that, traditionally, had temperature dependencies represented by empirical laws (“4TR” in the figure). Recently, a physics based law (Double Power Law - DPL) has been developed and adopted by the HITRAN (a spectroscopic database) committee. This article compares the performance of the empirical laws and the DPL to reproduce large amounts of calculated data. It shows that the new law results in better overall approximation of the temperature evolution of the spectroscopic parameters, requires less parameters and its structure is much simpler and more self-consistent than the empirical ones. Finally, the paper recommends the usage of the double power law and presents DPL parametrizations for the HITRAN database. These results are crucial for remote sensing of our atmosphere and determination of the vertical concentration profiles of pollutants.

Predict the concentration of methane

Gamache RR, Rey Michaël, Vispoel B, Tyuterev VG. 2019. Reduced Matrix Elements for collisionally induced transitions of 12CH4. Journal of Quantitative Spectroscopy and Radiative Transfer. DOI: 10.1016/j.jqsrt.2019.06.010.

To perform inversion of atmospheric spectra and precisely measure the concentration of methane in the Earth’s atmosphere or others (like Mars or Titan), it is required to characterize the infrared absorption by the gases present in atmospheres. This is done through the determination of the spectroscopic parameters of infrared absorption lines for each gas. This determination is usually realized experimentally for some lines, while calculations are needed for all lines. They can be made by semi-classical theory that requires a good knowledge of the interaction processes between molecules. In this work, the Reduced Matrix Elements for collisional induced transitions were computed from ab initio wave function for methane. They are an important part of the semi-classical line shape calculation. The obtained results will have an important environmental input since they will improve the knowledge of the methane in our atmosphere.

Predict the sensitivity of macroinvertebrates

Van den Berg SJP, Baveco H, Butler E, De Laender F, Focks A, Franco A, Rendal C, Van den Brink PJ. 2019. Modeling the Sensitivity of Aquatic Macroinvertebrates to Chemicals Using Traits. Environmental Science & Technology 53:6025–6034. DOI: 10.1021/acs.est.9b00893.

In the environmental risk assessment of chemicals, the determination of thresholds is essential. Usually, a few standard species are tested for effects of toxicants and results are then extrapolated to other species. The presented modelling tool allows to determine a ranking of the sensitivity of macroinvertebrates and provides thus a predictive trait model.

Stress, diversity & productivity

De Raedt J, Baert JM, Janssen CR, De Laender F. 2019. Stressor fluxes alter the relationship between beta-diversity and regional productivity. Oikos 0. DOI: 10.1111/oik.05191.

Dispersal of organisms can influence beta‐diversity and also regional productivity in heterogeneous environments. At the same time, the release of chemicals is stressful to ecosystems and can effect dispersal, but HOW? Experiments with two marine micro‐algae communities were conducted to shed light on this relationship. Similar to other studies, a positive relationship of beta-diversity and productivity was found in the absence of a stressor. However, when a stressor flux was present, this relationship became negative.

 

2018

Support global urban mapping

Forget, Y, Linard, C, Gilbert, M, Forget, Y, Linard, C, & Gilbert, M 2018, ‘Supervised Classification of Built-Up Areas in Sub-Saharan African Cities Using Landsat Imagery and OpenStreetMap’, Remote Sensing, vol. 10, no. 7, p. 1145, doi: 10.3390/rs10071145

Landsat (Satellite) images allow the production of high resolution built-up maps, but the amount of work to classify algorithms relying on supervised learning is tremendous, especially for highly heterogeneous urban environments. Volunteered Geographic Information (VGI) projects such as OpenStreetMap (OSM) provide an increasing amount of information on the earth’s surface that is useful to generate such maps. Here, a classification method is proposed that makes use of OSM to automatically collect training samples for supervised learning of built-up areas.

Social perspectives of climate change adaptations

Dujardin, S, Orban-Ferauge, F, Cañares, MP, & Dendoncker, N 2018, ‘Capturing multiple social perspectives on adaptation across scales: a Q-method analysis of actors from development planning in the Philippines’, Climate and Development, vol. 10, no. 5, pp. 458–470, doi: 10.1080/17565529.2017.1301863

This paper describes and analyses viewpoints regarding climate change adaptation held among key social actors from the field of development planning in the Philippines. Four empirically significant social perspectives are determined – institutional, grassroots, developmental, and physical planning – using Q-method, an intensive qualitative and quantitative technique. Major differences and commonalities between perspectives are highlighted, in addition to actors’ arguments used to justify claims. Drawing upon an actor-oriented approach, results contribute filling a knowledge gap in the literature on the need to develop approaches that can guide adaptation thinking in development planning.

Dujardin, S, Hermesse, J & Dendoncker, N 2018, 'Making space for experiential knowledge in climate change adaptation?: Insights from planning officers in Bohol, Philippines' Jàmbá: Journal of Disaster Risk Studies, vol 10, no. 1, a433. DOI:10.4102/jamba.v10i1.433

Forget Y, Shimoni M, Gilbert M, Linard C. 2018. Complementarity Between Sentinel-1 and Landsat 8 Imagery for Built-Up Mapping in Sub-Saharan Africa. Preprints 2018100695 DOI: 10.20944/preprints201810.0695.v1.

Nieves JJ, Sorichetta A, Linard C, Bondarenko M, Steele J, Stevens F, Gaughan AE, Carioli A, Clarke D, Esch T, Tatem AJ. 2018. Modelling Built-Settlements between Remotely-Sensed Observations. Preprints 2018120250 DOI: 10.20944/preprints201812.0250.v1.

Forget Y, Linard C, Gilbert M, Shimoni M, Lopez J. 2018. Fusion Scheme for Automatic and Large-Scaled Built-up Mapping. In: IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium. 2072–2075. DOI: 10.1109/IGARSS.2018.8518266.

Steele JE, Nieves J, Tatem AJ, Forget Y, Shimoni M, Linard C. 2018. Worldpop - Fusion of Earth and Big Data for Intraurban Population Mapping. In: IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium. 2070–2071. DOI: 10.1109/IGARSS.2018.8518181.

Lopes-Rodrigues M, Zanuy D, Alemán C, Michaux C, Perpète EA. 2018. 3D structure of a Brucella melitensis porin: molecular modelling in lipid membranes. Journal of Biomolecular Structure and Dynamics 0:1–13. DOI: 10.1080/07391102.2018.1529627.

Dye removal with natural clay

Chargui H, Hajjaji W, Wouters J, Yans J, Jamoussi F. 2018. Direct Orange 34 dye fixation by modified kaolin. Clay Minerals 53:271–287. DOI: 10.1180/clm.2018.18.

Direct Orange 34 is a highly toxic dye used in textile industries in Tunisia. Dye wastewater is carcinogenic, toxic and non-biodegradable, thus causing huge environmental problems. Due to their colloidal properties, clay minerals are efficient adsorbents and can effectively remove such dyes from aqueous solutions. Such naturally available clays have further the advantage that they are low-cost, abundant and non-toxic. This study tested the adsorption behaviour of modified (acid-activated and Fe-impregnated) kaolinite-rich clays from a local mine. The clays showed satisfactory affinity for adsorbing this reactive dye.

Review on neurotoxicity of chemicals

Legradi JB, Di Paolo C, Kraak MHS, van der Geest HG, Schymanski EL, Williams AJ, Dingemans MML, Massei R, Brack W, Cousin X, Begout M-L, van der Oost R, Carion A, Suarez-Ulloa V, Silvestre F, Escher BI, Engwall M, Nilén G, Keiter SH, Pollet D, Waldmann P, Kienle C, Werner I, Haigis A-C, Knapen D, Vergauwen L, Spehr M, Schulz W, Busch W, Leuthold D, Scholz S, vom Berg CM, Basu N, Murphy CA, Lampert A, Kuckelkorn J, Grummt T, Hollert H. 2018. An ecotoxicological view on neurotoxicity assessment. Environmental Sciences Europe 30:46. DOI: 10.1186/s12302-018-0173-x.

Thirtyeight recognized scientists emphasize the necessity to assess the thousands of chemicals that enter the natural environment due to human activities. Potential neurotoxicity has been predicted for 30 000 compounds. These can trigger diseases later in life, such as neurodegenerative diseases. Chronic pollution is to be considered as part of global change, such as climate change and biodiversity loss. A critical overview of the state of the art of hazard characterization, effects, bioassays and chemical approaches regarding neurotoxicity in organisms as well as for ecosystems.

Mangrove rivulus & endocrin disruptors

Voisin A-S, Kültz D, Silvestre F. 2018. Early-life exposure to the endocrine disruptor 17-α-ethinylestradiol induces delayed effects in adult brain, liver and ovotestis proteomes of a self-fertilizing fish. Journal of Proteomics. DOI: 10.1016/j.jprot.2018.12.008.

If you expose mangrove rivulus during early life stages to an endocrine disrupting chemical, their protein expression profile in brain, liver and gonads is changed in adult fish, 5 months after the end of the exposure. This study uses a modern proteomic workflow. It shows that early life stages are critical windows extremely sensitive to environmental pollutants. These can trigger molecular changes later in life, and possibly explain latent diseases.

Mangrove rivulus & neurotoxins

Carion A, Hétru J, Markey A, Suarez-Ulloa V, Silvestre F. 2018. Behavioral effects of the neurotoxin ß-N-methylamino-L-alanine on the mangrove rivulus (Kryptolebias marmoratus) larvae. Journal of Xenobiotics. DOI: 10.4081/xeno.2018.7820.

A first article based on preliminary data of two master students, Julie Hetru and Angèle Markay. The mangrove rivulus successfully served as an ecotoxicological model to assess the impacts of neurotoxins during fish development on behaviour at adult stage. Further long term effects (latent effects in adults and across generations) and the molecular mechanisms of neurotoxicity (epigenetics) are still under investigation.

Biomimetics: Porins & ~Natural Environment

Puiggalí-Jou A, Pawlowski J, del Valle LJ, Michaux C, Perpète EA, Sek S, Alemán C. 2018. Properties of Omp2a-Based Supported Lipid Bilayers: Comparison with Polymeric Bioinspired Membranes. ACS Omega 3:9003–9019. DOI: 10.1021/acsomega.8b00913.

This work focusses on the protein Omp2a in an ambient that is more similar to nature: a supported lipid bilayer (~ a planar in vitro assembly of lipids sitting on a solid support). The nanomechanical properties (elasticity, adhesion forces, deformation) and functionality of the resulting – more natural - bioinspired membrane was compared with those of polymeric nanomembranes (NMs). Results show that the protein is softer and more flexible than the lipid bilayer, allowing the passage of molecules with varying sizes and shapes. This character could truly mimic biological attributes. For technological applications on the other hand, the lipid bilayer is less suited than polymeric NMs due to its lower mechanical strength observed.

Biomimetics: Porins & Temperature

Lopes-Rodrigues M, Puiggalí-Jou A, Martí-Balleste D, del Valle LJ, Michaux C, Perpète EA, Alemán C. 2018. Thermomechanical Response of a Representative Porin for Biomimetics. ACS Omega 3:7856–7867. DOI: 10.1021/acsomega.8b00463.

Membrane proteins play a key role in many biological processes, such as cell recognition, signal transmission, enzymatic reactions, and transport of metabolites. Porins are proteins that can be immobilized onto outer membranes or also inside synthetic pores to fabricate smart biomimetric nanomembranes. They form water-filled open channels (β barrels) and allow the passive penetration of hydrophilic molecules, having thus the capacity to exchange ions or small nutrients. Of course, the nanostructure of the porin aggregate plays a crucial role in its functionality. The size and shape of these structures is influenced by the chemical environment. Here, the response of Omp2a, an often-used porin, to temperature increase is measured and compared to conventional proteins.

Drugs & Rainbow Trout

Schmitz M, Beghin M, Mandiki SNM, Nott K, Gillet M, Ronkart S, Robert C, Baekelandt S, Kestemont P. 2018. Environmentally-relevant mixture of pharmaceutical drugs stimulates sex-steroid hormone production and modulates the expression of candidate genes in the ovary of juvenile female rainbow trout. Aquatic Toxicology 205:89–99. DOI: 10.1016/j.aquatox.2018.10.006.

Pharmaceutical drugs can be found almost everywhere in our environment. Here, female rainbow trout were exposed to a mixture of pharmaceuticals as detected in the river Meuse (paracetamol, diclophenac, etc.). Elevated levels of sex hormones and of genes involved in steroidogenesis were found, which might lead to premature growth of previtellogenic follicles in the ovaries of pre-pubertal female fish. The effects appeared to be concentration-dependent, which stresses the importance of including environmental exposure concentrations in toxicological studies.

Triclosan & Zebrafish

Falisse E, Ducos B, Stockwell PA, Morison IM, Chatterjee A, Silvestre F. 2018. DNA methylation and gene expression alterations in zebrafish early-life stages exposed to the antibacterial agent triclosan. Environmental Pollution 243:1867–1877. DOI: 10.1016/j.envpol.2018.10.004.

Aim of this study was to identify the epigenetic effects of an exposure to a common pollutant (the antibacterial agent Triclosan) during the development of zebrafish. Triclosan is commonly used in soaps, toothpastes and cosmetics and is suspected to induce some endocrine disruption. DNA methylation, a common epigenetic mechanism, was affected by exposure to 50 and 100 µg/L of Triclosan. However, each exposure concentration showed a specific alteration pattern and was correlated to specific phenotypic effects. Further observation was that differential DNA methylation is mainly reported in introns and intergenic regions, the former being correlated to gene expression. Surprisingly, very few significant effects have been found in promotor regions. Further studies will investigate the possible long-term consequences of these alterations and the possible implications in terms of fitness and adaptation to environmental pollutants.

Biodiversity and ecosystem functioning under environmental stress

Baert, JM, Eisenhauer, N, Janssen, CR, De Laender, F (2018), Biodiversity effects on ecosystem functioning respond unimodally to environmental stress. Ecology Letters doi:10.1111/ele.13088

Understanding how biodiversity (B) affects ecosystem functioning (EF) is essential for assessing the consequences of ongoing biodiversity changes. Environmental conditions impact on these BEF relationships. With the help of a community model stemming form game‐theory, it is shown that along environmental stress gradients, the response of BEF interactions is unimodal. Depending on how stress affects species interactions, the ecological mechanisms underlying this response may vary. A global dataset of 44 experiments that cross biodiversity with environmental conditions was then analysed. The analysis confirms that at intermediate levels of environmental stress, the effect of biodiversity on ecosystem functioning tends to be greater. Results suggest that increases in stress from ongoing global environmental changes may amplify the consequences of biodiversity changes.

Chemical stress effects marine food webs

Mensens, C, De Laender, F, Janssen, CR, Rivera, FC, Sabbe, K and De Troch, M (2018), Selective and context‐dependent effects of chemical stress across trophic levels at the basis of marine food webs. Ecological Applications, 28: 1342-1353. doi:10.1002/eap.1737

Human activities and stressors increasingly impact the functioning of marine food webs, but are seldom included in ecological study designs. Further, diet quality is rarely highlighted in food web studies in a stress context, as opposed to diet quantity. This article measures the effects of metal and pesticide stress (copper and atrazine) on a benthic intertidal diatom community and how this impacts on biomass (diet quantity) and lipid (diet quality) production. Pesticides changed the community structure (selective effects) of diatoms to lipid-poor species, reducing diatom diet quality by up to 75%. Further, at high copper concentrations, diatoms lost 40% of their lipids (context‐dependent effect). These changes in diet quality led to consequences for the copepod grazers feeding on diatoms, even at stress levels where no changes in diatom lipid content had been detected.

Effects of an organic-inorganic chemical mixture on marine plankton

Filimonova, V, De Troch, M, Gonçalves, F, Marques, JC, Marques, SM, Gonçalves, AMM, & De Laender, F 2018, ‘Effects of a herbicide and copper mixture on the quality of marine plankton’, Ecotoxicology and Environmental Safety, vol. 156, pp. 9–17, doi: 10.1016/j.ecoenv.2018.02.038

Pesticides and metals are often used in agriculture and are therefore often simultaneously discharged to nearby estuarine and marine areas with unknown effects on food quality of aquatic organisms. This study investigates the effects of a mixture of copper (inorganic) and a herbicide (organic) on the quality of diatoms and copepods, which are highly important food sources for fish and marine animals. The effects of the metal-herbicide mixture on food quality of plankton were non-additive and the contaminants mixture had a stronger effect on food quality than single exposure. The species from a higher trophic level (i.e. copepods) was most sensitive to the chemical stressors.

Light shed on peptide-surfactant interactions

Roussel, G, Caudano, Y, Matagne, A, Sansom, MS, Perpète, EA, & Michaux, C 2018, ‘Peptide-surfactant interactions: A combined spectroscopic and molecular dynamics simulation approach’, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, vol. 190, pp. 464–470, doi: 10.1016/j.saa.2017.09.056

Sodium dodecyl sulphate (SDS) or sodium lauryl sulfate (SLS) is a highly effective anionic surfactant used in many cleaning and hygiene products (floor cleaners, shampoo, toothpaste,…). Other than classical chemical denaturants, it can already denature proteins at extremely weak (millimolar!) concentrations.  Despite its universal application, the exact nature of the protein-detergent interactions is still not thoroughly understood nor controlled. This study unravels at atomic resolution the effect of SDS detergent on the structure of two model peptides using a combined spectroscopic and computational approach.

Control the growth of germanium nanocrystals

Barba, D, Wang, C, Nélis, A, Terwagne, G & Rosei, F 2017, ‘Blocking germanium diffusion inside silicon dioxide using a co-implanted silicon barrier’, Journal of Applied Physics, vol. 123, no. 16, p. 161540. DOI: 10.1063/1.5002693

Germanium nanocrystals (Ge-NCs) are environmentally friendlier alternatives to classical ones containing toxic elements (e.g. mercury) and thus attract renewed scientific interest. Controlling their size defines many of their photophysical properties, which may improve the performance of numerous devices like solar cells, photodetectors, and lithium ion batteries.
This paper investigates the effect of co-implanting a silicon sublayer on the thermal diffusion of germanium ions implanted into SiO2. Although this technique affects the crystallinity of the formed Ge-NCs, it controls the spatial distribution of Germanium. This effect can be used to produce size-selective and depth-ordered nanostructured systems.

A special diet can improve the immune system of rainbow trout

Cornet, V, Ouaach, A, Mandiki, SNM, Flamion, E, Ferain, A, Van Larebeke, M, Lemaire, B, Reyes López, FE, Tort, L, Larondelle, Y & Kestemont, P 2018, ‘Environmentally-realistic concentration of cadmium combined with polyunsaturated fatty acids enriched diets modulated non-specific immunity in rainbow trout’, Aquatic Toxicology, vol. 196, pp. 104–116. https://doi.org/10.1016/j.aquatox.2018.01.012

 Fish are more and more exposed to stressors such as pollution, overcrowding and pathogen risks. Cadmium for example is a non-essential metal that often ends up in our rivers and lakes. Growing healthy fish in such contaminated environments depends among others on their nutrition. Scientists are therefore searching for food components, for example vegetable oils, that are able to improve fish health and growth. This publication shows that Cadmium (in concentrations as found in nature) can strongly impact the immune system of rainbow trout (Oncorhynchus mykiss). A specific diet, enriched with polyunsaturated fatty acids improved fish growth, provided protection against oxidative stress and stimulated their immunity

Bioinspired membranes: Learn from nature

Lopes-Rodrigues, M, Triguero, J, Torras, J, Perpète, EA, Michaux, C, Zanuy, D & Alemán, C 2018, ‘Influence of the surrounding environment in re-naturalized β-barrel membrane proteins’, Biophysical Chemistry, vol. 234, pp. 6–15. DOI: 0.1016/j.bpc.2017.12.003

 Porins, proteins acting as pores mediating the diffusion of small molecules through the membrane, are excellent candidates to design bioinspired membranes. These are powerful since, once immobilized into polymeric matrices, they can selectively separate undesired substances from liquid materials and for example be used for water purification. However, the fabrication of these protein-integrated devices depends on the stability of the porin structure, which can be spoiled or supported by the surrounding environment as reported in this publication.

Mercury affects the brain of peacock blennies

Naïja, A, Kestemont, P, Chénais, B, Haouas, Z, Blust, R, Helal, AN & Marchand, J 2018, ‘Effects of Hg sublethal exposure in the brain of peacock blennies Salaria pavo: Molecular, physiological and histopathological analysis’, Chemosphere, vol. 193, pp. 1094–1104. DOI: 10.1016/j.chemosphere.2017.11.118

Marine environments are contaminated by large amounts of toxicants including mercury (Hg). This poses a real concern for public health since the metal can accumulate and become toxic along the trophic chain. This study investigated any neurotoxic effects of Hg in the peacock blenny (Salaria pavo), a widely distributed fish at the Mediterranean and the North Atlantic coast. When individuals were exposed to a sublethal concentration of Hg their brain tissue was affected. However, previously measured Hg concentrations disappeared after several days suggesting that the brain of peacock blennies was able to detoxify the metal.

Van de Perre D, Roessink I, Janssen CR, Smolders E, De Laender F, Brink PJV den, Schamphelaere KACD. 2018. The combined and interactive effects of zinc, temperature, and phosphorus on the structure and functioning of a freshwater community. Environmental Toxicology and Chemistry 37:2413–2427. DOI: 10.1002/etc.4201.

2017

De Longueville, F, Hountondji, Y-C, Djivo, VP, Ozer, P & Henry, S 2017, 'Impacts des aérosols sahariens sur la santé respiratoire des enfants en Afrique de l’Ouest : étude préliminaire dans le Bénin septentrional' Sciences et Changements Planétaires/Sécheresse.

Kabaria, CW, Gilbert, M, Noor, AM, Snow, RW & Linard, C 2017, 'The impact of urbanization and population density on childhood Plasmodium falciparum parasite prevalence rates in Africa' Malaria Journal, vol 16, no. 1, 49. DOI: 10.1186/s12936-017-1694-2

Linard C, Kabaria CW, Gilbert M, Tatem AJ, Gaughan AE, Stevens FR, Sorichetta A, Noor AM, Snow RW. 2017. Modelling changing population distributions: an example of the Kenyan Coast, 1979–2009. International Journal of Digital Earth 10:1017–1029. https://doi.org/10.1080/17538947.2016.1275829.

Nieves Jeremiah J., Stevens Forrest R., Gaughan Andrea E., Linard Catherine, Sorichetta Alessandro, Hornby Graeme, Patel Nirav N., Tatem Andrew J. 2017. Examining the correlates and drivers of human population distributions across low- and middle-income countries. Journal of The Royal Society Interface 14:20170401. https://doi.org/10.1098/rsif.2017.0401.

Pezzulo C, Hornby GM, Sorichetta A, Gaughan AE, Linard C, Bird TJ, Kerr D, Lloyd CT, Tatem AJ. 2017. Sub-national mapping of population pyramids and dependency ratios in Africa and Asia. Scientific Data 4:170089. https://doi.org/10.1038/sdata.2017.89.

Baert, JM, De Laender, F & Janssen, CR 2017, 'The consequences of non-randomness in species-sensitivity in relation to functional traits for ecosystem-level effects of chemicals' Environmental Science and Technology, vol 51, no. 12, pp. 7228-7235. DOI: 10.1021/acs.est.7b00527

De Hoop, L, Viaene, KPJ, Schipper, AM, Huijbregts, MAJ, De Laender, F & Hendriks, AJ 2017, 'Time-varying effects of aromatic oil constituents on the survival of aquatic species: Deviations between model estimates and observations' Environmental Toxicology & Chemistry, vol 36, no. 1, pp. 128-136. DOI: 10.1002/etc.3508

De Raedt, J, Baert, JM, Janssen, CR & de Laender, F 2017, 'Non-additive effects of dispersal and selective stress on structure, evenness, and biovolume production in marine diatom communities' Hydrobiologia, vol 788, no.1, pp. 385-396. DOI: 10.1007/s10750-016-3016-z

Di Guardo, A, Morselli, M, Morabito, G, Semplice, M, Van den Brink, PJ & De Laender, F 2017, 'European environmental scenarios of chemical bioavailability in freshwater systems' Science of the Total Environment, vol 580, pp. 1237-1246. DOI: 10.1016/j.scitotenv.2016.12.084

Falisse, É, Voisin, A-S & Silvestre, F 2017, 'Impacts of triclosan exposure on zebrafish early-life stage: Toxicity and acclimation mechanisms' Aquatic Toxicology, vol 189, pp. 97-107. DOI: 10.1016/j.aquatox.2017.06.003

Franco, A, Price, O, Marshall, S, Jolliet, O, Van den Brink, P, Rico, A, Focks, A, De Laender, F & Ashauer, R 2017, 'Towards refined environmental scenarios for ecological risk assessment of down-the-drain chemicals in freshwater environments' Integrated Environmental Assessment and Management, vol 13, pp. 233-248. DOI: 10.1002/ieam.1801

Mensens, C, De Laender, F, Janssen, CR, Sabbe, K & De Troch, M 2017, 'Different response-effect trait relationships underlie contrasting responses to two chemical stressors' Journal of Ecology, vol 105, no. 6, pp. 1598-1609. DOI: 10.1111/1365-2745.12777

Naïja, A, Kestemont, P, Chénais, B, Haouas, Z, Blust, R, Helal, AN & Marchand, J 2017, 'Cadmium exposure exerts neurotoxic effects in peacock blennies Salaria pavo' Ecotoxicology and Environmental Safety, vol 143, pp. 217-227. DOI: 10.1016/j.ecoenv.2017.05.041

2016

De Longueville F, Hountondji Y-C, Kindo I, Gemenne F, Ozer P. 2016. Long-term analysis of rainfall and temperature data in Burkina Faso (1950–2013). International Journal of Climatology 36:4393–4405. DOI: 10.1002/joc.4640.

Ignacio JAF, Cruz GT, Nardi F, Henry S. 2016. Assessing the effectiveness of a social vulnerability index in predicting heterogeneity in the impacts of natural hazards: Case study of the Tropical Storm Washi flood in the Philippines. Vienna Yearbook of Population Research 2015:91–129. DOI: 10.1553/populationyearbook2015s91.

Gaughan, AE, Stevens, FR, Huang, Z, Nieves, JJ, Sorichetta, A, Lai, S, Ye, X, Linard, C, Hornby, GM, Hay, SI, Yu, H & Tatem, AJ 2016, 'Spatiotemporal patterns of population in mainland China, 1990 to 2010' Scientific Data, vol 3, 160005. DOI: 10.1038/sdata.2016.5

Kabaria, CW, Molteni, F, Mandike, R, Chacky, F, Noor, AM, Snow, RW & Linard, C 2016, 'Mapping intra-urban malaria risk using high resolution satellite imagery: A case study of Dar es Salaam' International Journal of Health Geographics, vol 15, no. 1, 26. DOI: 10.1186/s12942-016-0051-y

Zickgraf C, Vigil S, De Longueville F, Ozer P, Gemenne F. 2016. The Impact of Vulnerability and Resilience to Environmental Changes on Mobility Patterns in West Africa. World Bank. link

Zu Erbach-Schoenberg, E, Alegana, VA, Sorichetta, A, Linard, C, Lourenço, C, Ruktanonchai, NW, Graupe, B, Bird, TJ, Pezzulo, C, Wesolowski, A & Tatem, AJ 2016, 'Dynamic denominators: The impact of seasonally varying population numbers on disease incidence estimates' Population Health Metrics, vol 14, no. 1, 35. DOI: 10.1186/s12963-016-0106-0

Bonnineau, C, Scaion, D, Lemaire, B, Belpaire, C, Thomé, J-P, Thonon, M, Leermaker, M, Gao, Y, Debier, C, Silvestre, F, Kestemont, P & Rees, J-F 2016, 'Accumulation of neurotoxic organochlorines and trace elements in brain of female European eel (Anguilla anguilla)' Environmental Toxicology and Pharmacology, vol 45, pp. 346-355. DOI: 10.1016/j.etap.2016.06.009

De Hoop, L, Broch, O-J, Hendriks, AJ & De Laender, F 2016, 'Crude oil affecting the biomass of the marine copepod Calanus finmarchicus: comparing a simple and complex population model' Marine Environmental Research, vol 119, pp. 197–206. DOI: 10.1016/j.marenvres.2016.06.008

Dohmen, GP, Preuss, TG, Hamer, M, Galic, N, Strauss, T, van den Brink, PJ, De Laender, F & Bopp, S 2016, 'Population-level effects and recovery of aquatic invertebrates after multiple applications of an insecticide' Integrated Environmental Assessment and Management, vol 12, no. 1, pp. 67-81. DOI: 10.1002/ieam.1676

Dorts, J, Falisse, E, Schoofs, E, Flamion, E, Kestemont, P & Silvestre, F 2016, 'DNA methyltransferases and stress-related genes expression in zebrafish larvae after exposure to heat and copper during reprogramming of DNA methylation' Scientific Reports, vol 6, 34254. DOI: 10.1038/srep34254

Everaert, G, De Laender, F, Claessens, M, Baert, J, Monteyne, E, Roose, P, Goethals, PLM & Janssen, CR 2016, 'Realistic environmental mixtures of hydrophobic compounds do not alter growth of a marine diatom' Marine Pollution Bulletin, vol 102, no. 1, pp. 58-64. DOI: 10.1016/j.marpolbul.2015.11.058

Michaux, C, Roussel, G, Lopes-Rodrigues, M, Matagne, A & Perpète, EA 2016, 'Unravelling the mechanisms of a protein refolding process based on the association of detergents and co-solvents' Journal of Peptide Science, pp. 485-491. DOI: 10.1002/psc.2893

Naïja, A, Marchand, J, Kestemont, P, Haouas, Z, Blust, R, Chénais, B & Helal, AN 2016, 'Biomarkers assessment in the peacock blenny Salaria pavo exposed to cadmium' Environmental Science and Pollution Research, pp. 1-17. DOI: 10.1007/s11356-016-6754-6

Naïja, A, Marchand, J, Kestemont, P, Haouas, Z, Blust, R, Chénais, B & Helal, AN 2016, 'Mercury accumulation and its effects on molecular, physiological, and histopathological responses in the peacock blenny Salaria pavo' Environmental Science and Pollution Research, pp. 1-17. DOI: 10.1007/s11356-016-7401-y

Puiggalí-Jou, A, Pérez-Madrigal, MM, Del Valle, LJ, Armelin, E, Casas, MT, Michaux, C, Perpète, EA, Estrany, F & Alemán, C 2016, 'Confinement of a β-barrel protein in nanoperforated free-standing nanomembranes for ion transport' Nanoscale, vol 8, no. 38, pp. 16922-16935. DOI: 10.1039/c6nr04948f

Roland, K, Kestemont, P,  Dieu, M, Raes, M & Silvestre, F, 2016, 'Using a novel “Integrated Biomarker Proteomic” index to assess the effects of freshwater pollutants in European eel peripheral blood mononuclear cells' Journal of Proteomics, vol 137, pp. 83-96. DOI: 10.1016/j.jprot.2016.01.007

Schnitzler JG, Frédérich B, Dussenne M, Klaren PHM, Silvestre F, Das K. 2016. Triclosan exposure results in alterations of thyroid hormone status and retarded early development and metamorphosis in Cyprinodon variegatus. Aquatic Toxicology 181:1–10. DOI: 10.1016/j.aquatox.2016.10.019.

Voisin, AS, Fellous, A, Earley, RL & Silvestre, F 2016, 'Delayed impacts of developmental exposure to 17-α-ethinylestradiol in the self-fertilizing fish Kryptolebias marmoratus' Aquatic Toxicology, vol 180, pp. 247-257. DOI: 10.1016/j.aquatox.2016.10.003

 

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