Effect of aging on calcium signaling in C57Bl6J mouse cerebral arteries

In cerebral arteries, alterations of vascular reactivity have been observed but not well molecularly characterized. Therefore, we have hypothesized that cerebrovascular reactivity could be modified by aging via a modification of Ca²⁺ signaling in smooth muscle cells. Ca²⁺ signals and gene expression implicated in contraction have been measured in posterior and middle cerebral arteries from young (2–3 months) and old (20–22 months) C57Bl6/J mice. Aging induced a decrease of KCl- and caffeine-induced contraction as well as a decrease of the amplitudes and an increase of the durations of KCl- and caffeine-induced Ca²⁺ signals. These results could be linked with the decrease of gene expression coding for Cav1.2, RyR2, SERCA2, PLB, STIM1, TRIC-B, and the increase of FKBP12.6 and TPCN1 gene expression. Finally, aging induced a modification of InsP3 subtype expression pattern responsible for a modification of the InsP3 affinity to activate Ca²⁺ signals. These results show that aging induces a decrease of contractility correlated with modifications of the expression of genes encoding Ca²⁺ signaling toolkit. Globally, the amplitude of Ca²⁺ signals was decreased, whereas their duration was increased by a defection of Ca²⁺ store refilling

Prédiction du niveau trophique et hydrique des stations forestières en utilisant la flore indicatrice et des modèles de classification de Forêt Aléatoire

peer reviewedThe proper choice of the tree species to be grown in a specific forest site requires a good knowledge of the tree species autecology and a comprehensive description of the local environmental conditions. In Belgium (Western Europe), ecological forest site are classified according to three major gradients : climate, soil nutrient (fertility) and soil moisture regimes. Understory indicator species are used by practitioners to determine nutrient and moisture regimes, but requires a significant expertise of forest ecosystems. The present work aims in a first instance at modelling the nutrient and moisture regimes based on species composition. Secondly, a practical decision support tool is developped and made available in order to predict forest nutrient and moisture regime starting from a floristic relevé. To do so, we collected floristic relevés representing understory vegetation diversity in Belgium and covering all the nutrient and moisture gradient. The combination of soil and topographic measurements with the indicator plants presence/absence support forest scientists in inferring a nutrient and moisture regime to each relevé. The resulting dataset was balanced along the different nutrient or moisture regimes and Random Forest classification models were trained in order to predict the forest site characteristic from indicator species presence (or absence). One model was fitted for the prediction of the nutrient regime, exclusively based on the floristic information. A second one was trained to classify the moisture regime. Accurate predictions confirms the appropriate use of indicator species for the Belgian forest site classification. The two models are intregrated in a web application dedicated to forest practionners. This website enables the automatic determination of nutrient and moisture regimes from the species list of a floristic relevé

Seven recommendations to make your invasive alien species data more useful

Science-based strategies to tackle biological invasions depend on recent, accurate, well-documented, standardized and openly accessible information on alien species. Currently and historically, biodiversity data are scattered in numerous disconnected data silos that lack interoperability. The situation is no different for alien species data, and this obstructs efficient retrieval, combination, and use of these kinds of information for research and policy-making. Standardization and interoperability are particularly important as many alien species related research and policy activities require pooling data. We describe seven ways that data on alien species can be made more accessible and useful, based on the results of a European Cooperation in Science and Technology (COST) workshop: (1) Create data management plans; (2) Increase interoperability of information sources; (3) Document data through metadata; (4) Format data using existing standards; (5) Adopt controlled vocabularies; (6) Increase data availability; and (7) Ensure long-term data preservation. We identify four properties specific and integral to alien species data (species status, introduction pathway, degree of establishment, and impact mechanism) that are either missing from existing data standards or lack a recommended controlled vocabulary. Improved access to accurate, real-time and historical data will repay the long-term investment in data management infrastructure, by providing more accurate, timely and realistic assessments and analyses. If we improve core biodiversity data standards by developing their relevance to alien species, it will allow the automation of common activities regarding data processing in support of environmental policy. Furthermore, we call for considerable effort to maintain, update, standardize, archive, and aggregate datasets, to ensure proper valorization of alien species data and information before they become obsolete or lost

Wild boar movement ecology: what do we (don’t) know ?

Although subject of many researches since decades, movement studies have been recently enhanced by the emergence of the movement ecology paradigm (Nathan 2008). Under this paradigm, Nathan et al. (2008) proposed to break down movement of animal into four basic mechanistic components: i) internal states (motivation, physiology, why to move ?), ii) motion capacities (how to move ?), iii) navigation capacities and (when and where to move ?) and iv) external factors (physical environment and living organisms – conspecifics or not). Considering these four components of an individual’s movement, we reviewed literature dealing with wild boar (Sus scrofa L.), a species of important ecological and socio-economic concern, and tried to identify the key processes influencing this species’ movement. We conclude this review of the literature by highlighting the gaps in movement ecology of wild boar and suggesting further research directions under the light of the most recent used techniques

Dispersal and colonization history of agricultural lands by wild boar in Wallonia, southern Belgium

Les populations de sangliers augmentent en nombre et étendent leur aire de répartition un peu partout en Europe. En Wallonie, la population de sangliers a quadruplé en 30 ans. Plusieurs études se sont penchées sur le sujet et les raisons de cette augmentation concernent souvent l’influence du climat. Grâce aux différents suivis réalisés par le DEMNA, les déplacements au sein des populations de sangliers sont mieux compris. L’article se penche d’abord sur le potentiel de dispersion du sanglier en se basant sur les données de bagage de marcassins. Deux variables sont analysées : la distance parcourue dans le cadre de la dispersion natale (mouvement à sens unique à partir du site de naissance d’un individu jusqu’à son site de première reproduction) et le taux de cette dispersion natale. Quelques résultats provenant d’une étude génétique sont également présentés. Le génotypage de 1153 sangliers répartis sur l’ensemble de la Wallonie a mis en évidence quatre sous-populations génétiquement homogènes. Parallèlement à l’augmentation de la taille de ses populations, le sanglier a vu son aire de distribution s’accroître en Wallonie. Un suivi par enquête a été réalisé auprès des conseils cynégétiques et des agents du DNF pour mieux comprendre l’expansion géographique observée. Une première phase de l’enquête visait à retracer l’expansion géographique du sanglier en Wallonie. La seconde phase consistait à réaliser un état des lieux sur la situation actuelle de la distribution du sanglier en périphérie du sillon Sambre-et-Meuse

La flore forestière indicatrice : un nouveau guide

Présentation du Guide d'interprétation de la flore indicatrice en forê

Guide d'interprétation de la flore indicatrice en forêt

Forêt.Natur

Towards understanding wild boar Sus scrofa movement: a synthetic movement ecology approach

In recent decades, the wild boar Sus scrofa has simultaneously increased its population size and colonized new habitats, causing more ecological and socio-economic concern than perhaps any other ungulate species. However, the drivers and mechanisms of the species' spatial ecology remain poorly understood. Thanks to a recently developed framework, the movement ecology of any organism can now be tackled within a consistent and unified theoretical approach. Based on this framework, we reviewed the literature on wild boar movement ecology to assess current knowledge and to identify important gaps. By using important navigational (e.g. olfactory sense) and cognitive (e.g. spatial memory, learning from conspecifics) abilities, wild boar have developed complex movement strategies to cope with external factors. However, there is a lack of detailed information on the role played by the internal state (motivation) and motion capacity in shaping the spatial ability of the species. Specific aspects of the movement ecology of the wild boar, together with its high diet plasticity and its high prolificacy, are probably the most important causes of the rapid spread of wild boar worldwide. We hope our review will inspire other scientists to apply their biological models to the movement ecology paradigms. Furthermore, we suggest that future researchers dealing with the movement ecology of any species should explicitly state the components and interactions of the framework investigated to facilitate further understanding and comparison among studies

Polysaccharide-layered double hydroxide-aldolase biohybrid beads for biocatalysed CC bond formation.

International audienceThis study describes the design a novel microbioreactor for the biocatalysed asymmetric synthesis of polyhydroxylated compounds. The bioreactor was elaborated by a hierarchical assembly of a recombinant fructose-6-phosphate aldolase (FSAwt), layered double hydroxides (LDH) nanoplatelets and polysaccharide beads. Various polysaccharides were tested to encapsulate FSAwt and pre-immobilised FSAwt in LDH (FSAwt@Mg2Al-LDH). ι-Carrageenan appears as the most suitable candidate to prepare biohybrid beads. The retained activities in ι-carrageenan beads were measured for both free FSAwt and immobilised FSAwt revealing a 3 fold higher activity in favour of the pre-immobilised FSA. This result was probably due to a positive interaction between the negatively charged polysaccharide and the positively charged LDH layers. The catalytic activity, the recyclability and the storage of the beads were studied in addition to the leakage of FSAwt activity from beads. Nanostructuration of both FSAwt/ι-carr and FSAwt@Mg2Al-LDH/ι-carr was investigated by structural and textural characterization techniques