The Anopheles dirus complex: spatial distribution and environmental drivers

BACKGROUND: The Anopheles dirus complex includes efficient malaria vectors of the Asian forested zone. Studies suggest ecological and biological differences between the species of the complex but variations within species suggest possible environmental influences. Behavioural variation might determine vector capacity and adaptation to changing environment. It is thus necessary to clarify the species distributions and the influences of environment on behavioural heterogeneity. METHODS: A literature review highlights variation between species, influences of environmental drivers, and consequences on vector status and control. The localisation of collection sites from the literature and from a recent project (MALVECASIA) produces detailed species distributions maps. These facilitate species identification and analysis of environmental influences. RESULTS: The maps give a good overview of species distributions. If species status partly explains behavioural heterogeneity, occurrence and vectorial status, some environmental drivers have at least the same importance. Those include rainfall, temperature, humidity, shade, soil type, water chemistry and moon phase. Most factors are probably constantly favourable in forest. Biological specificities, behaviour and high human-vector contact in the forest can explain the association of this complex with high malaria prevalence, multi-drug resistant Plasmodium falciparum and partial control failure of forest malaria in Southeast Asia. CONCLUSION: Environmental and human factors seem better than species specificities at explaining behavioural heterogeneity. Although forest seems essential for mosquito survival, adaptations to orchards and wells have been recorded. Understanding the relationship between landscape components and mosquito population is a priority in foreseeing the influence of land-cover changes on malaria occurrence and in shaping control strategies for the future

Face à l’épuisement du pétrole, quel rôle pour l’aménagement du territoire en Wallonie ?

Que fera-t-on quand il n’y aura plus de pétrole ? Pour contribuer à répondre à cette question, ce numéro de Regards économiques analyse dans quelle mesure l’aménagement du territoire pourrait permettre de réduire la dépendance au pétrole de la Wallonie à moyen et long terme. Une analyse à moyen terme révèle une vulnérabilité-revenu certaine des communes rurales à un choc pétrolier. Une analyse de long terme, prospective, révèle que bouger moins peut être plus efficace que bouger mieux. A partir de ces résultats, l’article propose une série de mesures de politique économique et d’aménagement du territoire destinées à réduire la dépendance au pétrole de la Wallonie à moyen et long termes.

Les nouveaux défis du développement territorial en Wallonie

Dans le cadre des travaux d’actualisation du Schéma de Développement de l'Espace Régional (SDER), le Gouvernement Wallon a retenu six défis prioritaires : la démographie, le climat, l’énergie, la compétitivité, la cohésion sociale et la mobilité. Les différences de nature et de statut de ces défis sont manifestes. Toutefois trois grands traits communs peuvent être mis en évidence dans le cadre de leur définition : les défis sont pour partie exogènes au territoire wallon ; ils sont de nature « politique » et ils n’étaient pas suffisamment pris en compte dans le SDER de 1999. Les auteurs s’attachent à clarifier les pressions que ces défis imposent en Wallonie, mettant l’accent mis sur la manière dont les défis se traduisent spécifiquement sur le territoire, en identifiant les tendances observées et les hypothèses d’évolution aux horizons 2020 et 2040 afin de dégager les enjeux territoriaux et leviers d'action de l'aménagement du territoire à mobiliser pour y faire face.Actualisation du SDER - Diagnostic territoria

Predicted Distribution of Major Malaria Vectors Belonging to the Anopheles dirus Complex in Asia : Ecological Niche and Environmental Influences

Methods derived from ecological niche modeling allow to define species distribution based on presence-only data. This is particularly useful to develop models from literature records such as available for the Anopheles dirus complex, a major group of malaria mosquito vectors in Asia. This research defines an innovative modeling design based on presence-only model and hierarchical framework to define the distribution of the complex and attempt to delineate sibling species distribution and environmental preferences. At coarse resolution, the potential distribution was defined using slow changing abiotic factors such as topography and climate representative for the timescale covered by literature records of the species. The distribution area was then refined in a second step using a mask of current suitable land cover. Distribution area and ecological niche were compared between species and environmental factors tested for relevance. Alternatively, extreme values at occurrence points were used to delimit environmental envelopes. The spatial distribution for the complex was broadly consistent with its known distribution and influencing factors included temperature and rainfall. If maps developed from environmental envelopes gave similar results to modeling when the number of sites was high, the results were less similar for species with low number of recorded presences. Using presence-only models and hierarchical framework this study not only predicts the distribution of a major malaria vector, but also improved ecological modeling analysis design and proposed final products better adapted to malaria control decision makers. The resulting maps can help prioritizing areas which need further investigation and help simulate distribution under changing conditions such as climate change or reforestation. The hierarchical framework results in two products one abiotic based model describes the potential maximal distribution and remains valid for decades and the other including a biotic mask easy to update with frequently available information gives current species distribution

Etude sur l’imperméabilisation en Région bruxelloise et les mesures envisageables en matière d'urbanisme pour améliorer la situation imperméabilisation

Rapport finalinfo:eu-repo/semantics/publishe

Predicted potential and current distribution area for <i>Anopheles dirus sensu lato.</i>

<p>The produced maps show in grey forested areas not suitable according to abiotic factor, in yellow the potential distribution based on abiotic factor but where forest is not present (potential niche) and the distribution as defined by favorable abiotic and biotic factors (“realized niche”). Performance tests for the model include test Gain (1.38), test AUC (0.90) and test extrinsic omission rate based on maximum test sensitivity plus specificity (6%).</p

Performance from univariate models.

<p>Gain or performance from univariate models: – (<0.25),–(0.25–0.5), *(above 0.5), **(above 0.75) and ***(above 1). Variables with training gain under 0.5 for all species are not presented and include: MMAXRAIN, QMAXRAIN, NMINRAIN, QMINRAIN, MMINCVRAIN, MMENSUN, SLOPE, FLOW. For each relevant variable, the suitability value for presence is defined. The letters refers to the text and to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050475#pone-0050475-g004" target="_blank">Figure 4</a>.</p

Similarity dendrogram.

<p>Similarity dendrogram based on Ward clustering method and modified Hellinger distance.</p