Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
14
result(s) for
"Martin, Raphaeel"
Sort by:
Climate change impacts on European agriculture revisited: adding the economic dimension of grasslands
by
Aghajanzadeh-Darzi, Parisa
,
Jayet, Pierre-Alain
,
Unité Mixte de Recherche sur l'Ecosystème Prairial - UMR (UREP) ; Institut National de la Recherche Agronomique (INRA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)
in
agricultural products
,
Air pollution
,
Analysis
2017
Forage and more widely grassland systems are difficult to analyze in economic terms because a large proportion of what is produced is not marketed. Economic misestimation of these farm products may dramatically alter projected climate change impacts. This study estimates the economic value of grass and assesses the impact of climatic variations on grassland–livestock systems by taking various environmental and climatic factors into account. Accordingly, grass yield responses to nitrogen inputs (N-yield functions) have been simulated using the grassland biogeochemical PaSim model and then fed into the economic farm-type supply AROPAj model. We developed a computational method to estimate shadow prices of grass production, allowing us to better estimate the effects of climatic variability on grassland and crop systems. This approach has been used on a European scale under two Intergovernmental Panel on Climate Change climate scenarios (AR4 A2 and B1). Results show a significant change in land use over time. Accordingly, due to decreases in feed expenses, farmers may increase livestock, thereby increasing overall greenhouse gas emissions for all scenarios considered. As part of autonomous adaptation byfarming systems, N-yield functions extending to pastures and fodders allow us to improve the model and to refineresults when marketed and non-marketed crops are considered in a balanced way.
Journal Article
Modeled Changes in Potential Grassland Productivity and in Grass-Fed Ruminant Livestock Density in Europe over 1961-2010: e0127554
2015
About 25% of European livestock intake is based on permanent and sown grasslands. To fulfill rising demand for animal products, an intensification of livestock production may lead to an increased consumption of crop and compound feeds. In order to preserve an economically and environmentally sustainable agriculture, a more forage based livestock alimentation may be an advantage. However, besides management, grassland productivity is highly vulnerable to climate (i.e., temperature, precipitation, CO2 concentration), and spatial information about European grassland productivity in response to climate change is scarce. The process-based vegetation model ORCHIDEE-GM, containing an explicit representation of grassland management (i.e., herbage mowing and grazing), is used here to estimate changes in potential productivity and potential grass-fed ruminant livestock density across European grasslands over the period 1961-2010. Here \"potential grass-fed ruminant livestock density\" denotes the maximum density of livestock that can be supported by grassland productivity in each 25 km 25 km grid cell. In reality, livestock density could be higher than potential (e.g., if additional feed is supplied to animals) or lower (e.g., in response to economic factors, pedo-climatic and biotic conditions ignored by the model, or policy decisions that can for instance reduce livestock numbers). When compared to agricultural statistics (Eurostat and FAOstat), ORCHIDEE-GM gave a good reproduction of the regional gradients of annual grassland productivity and ruminant livestock density. The model however tends to systematically overestimate the absolute values of productivity in most regions, suggesting that most grid cells remain below their potential grassland productivity due to possible nutrient and biotic limitations on plant growth. When ORCHIDEE-GM was run for the period 1961-2010 with variable climate and rising CO2, an increase of potential annual production (over 3%) per decade was found: 97% of this increase was attributed to the rise in CO2, -3% to climate trends and 15% to trends in nitrogen fertilization and deposition. When compared with statistical data, ORCHIDEE-GM captures well the observed phase of climate-driven interannual variability in grassland production well, whereas the magnitude of the interannual variability in modeled productivity is larger than the statistical data. Regional grass-fed livestock numbers can be reproduced by ORCHIDEE-GM based on its simple assumptions and parameterization about productivity being the only limiting factor to define the sustainable number of animals per unit area. Causes for regional model-data misfits are discussed, including uncertainties in farming practices (e.g., nitrogen fertilizer application, and mowing and grazing intensity) and in ruminant diet composition, as well as uncertainties in the statistical data and in model parameter values.
Journal Article
Impacts of global change on species distributions: obstacles and solutions to integrate climate and land use
2017
Aim: The impact of multiple stressors on biodiversity is one of the most pressing questions in ecology and biodiversity conservation. Here we critically assess how often and efficiently two main drivers of global change have been simultaneously integrated into research, with the aim of providing practical solutions for better integration in the future. We focus on the integration of climate change (CC) and land‐use change (LUC) when studying changes in species distributions. Location: Global. Methods: We analysed the peer‐reviewed literature on the effects of CC and LUC on observed changes in species distributions, i.e. including species range and abundance, between 2000 and 2014. Results: Studies integrating CC and LUC remain extremely scarce, which hampers our ability to develop appropriate conservation strategies. The lack of CC–LUC integration is likely to be a result of insufficient recognition of the co‐occurrence of CC and LUC at all scales, covariation and interactions between CC and LUC, as well as correlations between species thermal and habitat requirements. Practical guidelines for the study of these interactive effects include considering multiple drivers and processes when designing studies, using available long‐term datasets on multiple drivers, revisiting single‐driver studies with additional drivers or conducting comparative studies and meta‐analyses. Combining various methodological approaches, including time lags and adaptation processes, represent further avenues to improve global change science. Main conclusions: Despite repeated claims for a better integration of multiple drivers, the effects of CC and LUC on species distributions and abundances have been mostly studied in isolation, which calls for a shift of standards towards more integrative global change science. The guidelines proposed here will encourage study designs that account for multiple drivers and improve our understanding of synergies or antagonisms among drivers.
Journal Article
Landscape connectivity, habitat structure and activity of bat guilds in farmland-dominated matrices
by
Frey-Ehrenbold, Annie
,
Obrist, Martin K.
,
Arlettaz, Raphaël
in
acoustic monitoring
,
Acoustics
,
Agricultural land
2013
1. Agricultural intensification has caused a decline in structural elements in European farmland, where natural habitats are increasingly fragmented. The loss of habitat structures has a detrimental effect on biodiversity and affects bat species that depend on vegetation structures for foraging and commuting. 2. We investigated the impact of connectivity and configuration of structural landscape elements on flight activity, species richness and diversity of insectivorous bats and distinguished three bat guilds according to species-specific bioacoustic characteristics. We tested whether bats with shorter-range echolocation were more sensitive to habitat fragmentation than bats with longer-range echolocation. We expected to find different connectivity thresholds for the three guilds and hypothesized that bats prefer linear over patchy landscape elements. 3. Bat activity was quantified using repeated acoustic monitoring in 225 locations at 15 study plots distributed across the Swiss Central Plateau, where connectivity and the shape of landscape elements were determined by spatial analysis (GIS). Spectrograms of bat calls were assigned to species with the software BATIT by means of image recognition and statistical classification algorithms. 4. Bat activity was significantly higher around landscape elements compared to open control areas. Short- and long-range echolocating bats were more active in well-connected landscapes, but optimal connectivity levels differed between the guilds. Species richness increased significantly with connectivity, while species diversity did not (Shannon's diversity index). Total bat activity was unaffected by the shape of landscape elements. 5. Synthesis and applications. This study highlights the importance of connectivity in farmland landscapes for bats, with shorter-range echolocating bats being particularly sensitive to habitat fragmentation. More structurally diverse landscape elements are likely to reduce population declines of bats and could improve conditions for other declining species, including birds. Activity was highest around optimal values of connectivity, which must be evaluated for the different guilds and spatially targeted for a region's habitat configuration. In a multispecies approach, we recommend the reintroduction of structural elements to increase habitat heterogeneity should become part of agri-environment schemes.
Journal Article
Peripheral Venous Catheter-Related Adverse Events: Evaluation from a Multicentre Epidemiological Study in France (the CATHEVAL Project)
2017
Peripheral venous catheters (PVC) are medical devices most frequently used during hospital care. Although the frequency of specific PVC-related adverse events (PVCAEs) has been reported, the global risk related to the insertion of this device is poorly estimated. The aim of this study is to determine the incidence of PVCAEs during the indwell time, after catheter removal, and to identify practice-mirroring risk factors.
A prospective observational study was conducted as a part of a research project, called CATHEVAL, in one surgery ward and four medicine wards from three public general tertiary care hospitals in Northern France that were invited to participate between June-2013 and June-2014. Each participating ward included during a two-month study period all patients older than 15 years carrying a PVC. All inserted PVCs were monitored from insertion of PVC to up to 48 hours after removal. Monitored data included several practice-mirroring items, as well as the occurrence of at least one PVCAE. A multivariate Cox proportional hazard model, based on a marginal risk approach, was used to identify factors associated with the occurrence of at least one PVCAE.
Data were analysed for 815 PVCs (1964 PVC-days) in 573 patients. The incidence of PVCAE was 52.3/100 PVCs (21.9/100 PVC-days). PVCAEs were mainly clinical: phlebitis (20.1/100 PVCs), haematoma (17.7/100 PVCs) and liquid/blood escape (13.1/100 PVCs). Infections accounted for only 0.4/100 PVCs. The most frequent mechanical PVCAEs, was obstruction/occlusion of PVC (12.4/100 PVCs). The incidence of post-removal PVCAEs was 21.7/100 PVCs. Unstable PVC and unclean dressing were the two main risk factors.
Limitation of breaches in healthcare quality including post-removal monitoring should be reinforced to prevent PVC-related adverse events in hospital settings.
Journal Article
Microfluidics-assisted fluorescence in situ hybridization for advantageous human epidermal growth factor receptor 2 assessment in breast cancer
2017
Fluorescence in situ hybridization (FISH) is one of the recommended techniques for human epidermal growth factor receptor 2 (HER2) status assessment on cancer tissues. Here we develop microfluidics-assisted FISH (MA-FISH), in which hybridization of the FISH probes with their target DNA strands is obtained by applying square-wave oscillatory flows of diluted probe solutions in a thin microfluidic chamber of 5 μl volume. By optimizing the experimental parameters, MA-FISH decreases the consumption of the expensive probe solution by a factor 5 with respect to the standard technique, and reduces the hybridization time to 4 h, which is four times faster than in the standard protocol. To validate the method, we blindly conducted HER2 MA-FISH on 51 formalin-fixed paraffin-embedded tissue slides of 17 breast cancer samples, and compared the results with standard HER2 FISH testing. HER2 status classification was determined according to published guidelines, based on average number of HER2 copies per cell and average HER2/CEP17 ratio. Excellent agreement was observed between the two methods, supporting the validity of MA-FISH and further promoting its short hybridization time and reduced reagent consumption.
Journal Article
Habitat selection of three cryptic Plecotus bat species in the European Alps reveals contrasting implications for conservation
by
Obrist, Martin K.
,
Arlettaz, Raphaël
,
Ecker, Klaus
in
Alps region
,
Animal, plant and microbial ecology
,
Applied ecology
2013
Assessing the ecological requirements of species coexisting within a community is an essential requisite for developing sound conservation action. A particularly interesting question is what mechanisms govern the stable coexistence of cryptic species within a community, i.e. species that are almost impossible to distinguish. Resource partitioning theory predicts that cryptic species, like other sympatric taxa, will occupy distinct ecological niches. This prediction is widely inferred from eco-morphological studies. A new cryptic long-eared bat species,
Plecotus macrobullaris,
has been recently discovered in the complex of two other species present in the European Alps, with even evidence for a few mixed colonies. This discovery poses challenges to bat ecologists concerned with planning conservation measures beyond roost protection. We therefore tested whether foraging habitat segregation occurred among the three cryptic
Plecotus
bat species in Switzerland by radiotracking 24 breeding female bats (8 of each species). We compared habitat features at locations visited by a bat versus random locations within individual home ranges, applying mixed effects logistic regression. Distinct, species-specific habitat preferences were revealed.
P. auritus
foraged mostly within traditional orchards in roost vicinity, with a marked preference for habitat heterogeneity.
P. austriacus
foraged up to 4.7 km from the roost, selecting mostly fruit tree plantations, hedges and tree lines.
P. macrobullaris
preferred patchy deciduous and mixed forests with high vertical heterogeneity in a grassland dominated-matrix. These species-specific habitat preferences should inform future conservation programmes. They highlight the possible need of distinct conservation measures for species that look very much alike.
Journal Article
The immunopotentiating effects of shark-derived protein hydrolysate
by
Beaulieu, Martin
,
Mallet, Jean-François
,
Duarte, Jairo
in
absorption barrier
,
Administration, Oral
,
Animals
2014
Peptides derived from natural sources can act as immunomodulating agents and prevent infections. The aim of this study was to investigate the immunopotentiating and protective effects of a shark-derived protein hydrolysate (SPH) against an enterotoxigenic Escherichia coli H10407 infection in a murine model.
Mice were fed an aqueous solution of SPH for 7 days before being inoculated with an experimental enterotoxigenic Escherichia coli H10407 infection. After euthanasia, small intestines were removed for histological study and the number of IgA and IgG producing cells was determined by direct immunofluorescence. Cytokines were measured in the serum and the intestinal fluid.
The oral administration of SPH enhanced the gut barrier function via up-regulation of immunoglobulin A-producing cells and intestinal cytokines production, including interleukin-6 and tumor necrosis factor-α. The increase of transforming growth factor-β and interleukin-10 contribute to the down-regulation of uncontrolled-inflammatory reaction induced by E. coli infection. From these results, the anti-inflammatory properties of SPH may be caused by regulation and priming mechanisms of the immune system.
Enzymatic protein degradation confers immunomodulating and protective potentials to shark proteins and the resulted peptides could be used as an alternative therapy to reduce the risk of bacterial infections and inflammatory-related diseases.
Journal Article
Self-compacting concrete using flash-metakaolin: design method
by
Escadeillas, Gilles
,
Mouret, Michel
,
Cyr, Martin
in
Aggregates
,
Building construction
,
Building Materials
2015
A simple diphasic approach was applied to assess the self-compacting ability of concrete incorporating flash-metakaolin as the sole mineral admixture. The approach was based on tools available in the literature. At cement paste scale (cement + metakaolin + water + HWRA), interactions among all the constituents were considered by means of the wet packing method. Starting from the water volume just necessary to fill the voids between suspended powder materials at maximum packing density, an excess water volume was deduced to adjust the paste flow for self-compacting applications. At aggregate scale (sand + gravel), the water volume retained by the projected granular skeleton (maximum packing) was demonstrated not to alter the flow properties of the paste. The paste/aggregate association was tested with Ordinary Portland Cement (OPC), blended cements (limestone or slag), polycarboxylate-type high range water reducing agent (HRWRA) and rounded siliceous sand (0/4 mm) and gravel (4/14 mm). Results showed that the metakaolin did not act as a filler, and induced a decrease in the wet packing density because of its particle size, which was greater than or similar to that of the cement particles. In addition, the BET surface area was a relevant criterion for the optimization of the paste flow. With regard to industrial applications, viscosity measurements could be simplified by the Marsh cone flow test. Results also showed that the paste/aggregate association initially tested and validated with limestone fillers could be adapted to the design of self-compacting concrete incorporating metakaolin. The viscosity criterion determined for proper flow of paste incorporating limestone filler remained true provided that the mixing time was prolonged at the stage of the rheological characterization of cement/metakaolin suspensions.
Journal Article
Reduced PBR/TSPO Expression After Minocycline Treatment in a Rat Model of Focal Cerebral Ischemia: A PET Study Using 18FDPA-714
by
Tavitian, Bertrand
,
Dollé, Frédéric
,
Martín, Abraham
in
Animals
,
Brain Ischemia - diagnostic imaging
,
Brain Ischemia - metabolism
2011
Background
Many new candidate pharmaceuticals designed to improve recovery after stroke have been proposed recently, but there are still too few molecular imaging methods capable to assess their efficacy. A hallmark of the inflammatory reaction that follows focal cerebral ischemia is overexpression of the mitochondrial peripheral benzodiazepine receptor/18 kDa translocator protein (PBR/TSPO) in the monocytic lineage and astrocytes. This overexpression can be imaged with positron emission tomography (PET) using PBR/TSPO-selective radioligands such as [
18
F]DPA-714.
Purpose
Here, we tested whether PET with [
18
F]DPA-714 would evidence the effect of minocycline, a broad spectrum antibiotic presently tested as neuroprotective agent after stroke, on the inflammatory reaction induced in an experimental model of stroke.
Procedures
Ten rats were subjected to a 2-h transient middle cerebral artery occlusion with reperfusion. Minocycline or saline was intravenously administrated 1 h after reperfusion and daily during the following 6 days. PET studies were performed using [
18
F]DPA-714 at 7 days after cerebral ischemia.
Results
In vivo
PET imaging showed a significant decrease in [
18
F]DPA-714 uptake at 7 days after cerebral ischemia in rats treated with minocycline with respect to saline-treated animals. Minocycline treatment had no effect on the size of the infarcted area.
Conclusion
Minocycline administered daily during 7 days after ischemia decreases [
18
F]DPA-714 binding, suggesting that the drug exerts an anti-inflammatory activity. [
18
F]DPA-714 PET is a useful biomarker to study novel anti-inflammatory strategies in experimental cerebral ischemia.
Journal Article