Search results for "mit"
showing 10 items of 11910 documents
Green methodology for quality control of elemental content of infant milk powder
2019
Abstract A green methodology for the direct determination of elemental content in infant milk powder samples from 0 to 3 years was developed. A portable energy dispersive X-ray fluorescence (ED-XRF) tool has been used as a direct method for the quantification of five essential elements (Ca, K, Fe, Cu and Zn). For analysis pellets from 0.8 g of each sample weight were made and analyzed. Due to the high dependence of the ED-XRF signal with the sample matrix, external calibrations using cocoa powder diluted with glucose were performed. Infant milk samples were diluted with lactose and the signals were interpolated in the external calibrations. Concentrations obtained by ED-XRF were compared wi…
Mitochondrial phylogeography of the edible dormouse (Glis glis) in the western Palearctic region
2010
International audience; This study describes in detail the phylogeoraphic pattern Of the edible dormouse (Glis glis) a European rodent With pronounced hibernating behavior We Used sequences of 831 base pairs of the mitochondrial DNA cytochrome-b gene from 130 edible dormice collected at 43 localities (throughout Its distribution. Our results reveal presence of 3 main haplogroups: Sicilian, South Italian (restricted to the Calabrian region) (a widespread lineage corresponding to all remaining western, central. and eastern European populations). Examination of paleontological data confirms refugial regions for G,Its in the 3 Mediterranean peninsulas, although overall low genetic diversity is …
Technical Solutions to Mitigate Shifting Fish Fauna Zones Impacted by Long Term Habitat Degradation in the Bistra Mărui River – Study Case
2018
Abstract The Bistra Mărului River fish fauna has been severely impacted by man-made activities, especially through longitudinal fragmentation, over the past 40 years. Fish fauna monitoring revealed structural changes and technical methods have been proposed, in order to restore the natural connectivity and the conservation of fish species. Benefits should accrue for key species: Salmo trutta fario, Cottus gobio, Thymallus thymallus, Eudontomyzon danfordi, Eudontomyzon vladykovi, Gobio uranoscopus, Barbus meridionalis, and Condrostoma nasus.
Genetic variability in Peregrine falcon populations of the Western Palaearctic region
2018
We analyzed variation in ten polymorphic microsatellites and a portion of cytochrome b mitochondrial DNA in 4 populations of the Peregrine falcon (Falco peregrinus). living in northern and southern Italy. Spain and Czech Republic to assess species diversity in the poorly investigated Western Palearctic region. The Spanish population lives in the contact zone between F. peregrinus peregrinus and F. p. brookei. both the northern Italian and the Czech populations live within the range of F. p. peregrinus and the southern Italian is within the F. p. brookei. We added to our cytochrome b sequence dataset comprising 81 samples. previously published mitochondrial DNA sequences (n = 31) of English …
Eliciting expert knowledge to inform stock status for data-limited stock assessments
2019
Data-limited fisheries are a major challenge for stock assessment analysts, as many traditional data-rich models cannot be implemented. Approaches based on stock reduction analysis offer simple ways to handle low data availability, but are particularly sensitive to assumptions on relative stock status (i.e., current biomass compared to unperturbed biomass). For the vast majority of data-limited stocks, stock status is unmeasured. The present study presents a method to elicit expert knowledge to inform stock status and a novel, user-friendly on-line application for expert elicitation. Expert opinions are compared to stock status derived from data-rich models. Here, it is evaluated how expert…
Species specificity of trail pheromones of fungus-growing termites from northern Vietnam
2001
Trail-following pheromones were studied in four fungus-growing termites from northern Vietnam: Macrotermes annandalei, M. barneyi, Odontotermes hainanensis and O. maesodensis. From bioassays, we suggest that trail pheromones of these species are composed of a common or anony-mous signal, as well as species-specific signals. The anonymous signal has been identified by GC-MS as (Z)-dodec-3-en-1-ol for each species from extracts of sternal glands and from solid phase microextraction of the surface of their sternal gland. This compound is secreted in much higher quantities (up to 1.4 ng/worker) than dodecatrienol, another anonymous signal of trail-following in termites. (Z)-dodec-3-en-1-ol is a…
Bivalve shell formation in a naturally CO2-enriched habitat: Unraveling the resilience mechanisms from elemental signatures
2018
Abstract Marine bivalves inhabiting naturally pCO2-enriched habitats can likely tolerate high levels of acidification. Consequently, elucidating the mechanisms behind such resilience can help to predict the fate of this economically and ecologically important group under near-future scenarios of CO2-driven ocean acidification. Here, we assess the effects of four environmentally realistic pCO2 levels (900, 1500, 2900 and 6600 μatm) on the shell production rate of Mya arenaria juveniles originating from a periodically pCO2-enriched habitat (Kiel Fjord, Western Baltic Sea). We find a significant decline in the rate of shell growth as pCO2 increases, but also observe unchanged shell formation r…
Light availability and land‐use history drive biodiversity and functional changes in forest herb layer communities
2020
International audience; A central challenge of today's ecological research is predicting how ecosystems will develop under future global change. Accurate predictions are complicated by (a) simultaneous effects of different drivers, such as climate change, nitrogen deposition and management changes; and (b) legacy effects from previous land use. We tested whether herb layer biodiversity (i.e. richness, Shannon diversity and evenness) and functional (i.e. herb cover, specific leaf area [SLA] and plant height) responses to environmental change drivers depended on land-use history. We used resurvey data from 192 plots across nineteen European temperate forest regions, with large spatial variabi…
Simple learning rules to cope with changing environments
2008
10 pages; International audience; We consider an agent that must choose repeatedly among several actions. Each action has a certain probability of giving the agent an energy reward, and costs may be associated with switching between actions. The agent does not know which action has the highest reward probability, and the probabilities change randomly over time. We study two learning rules that have been widely used to model decision-making processes in animals-one deterministic and the other stochastic. In particular, we examine the influence of the rules' 'learning rate' on the agent's energy gain. We compare the performance of each rule with the best performance attainable when the agent …
Trail-following pheromones in basal termites, with special reference to Mastotermes darwiniensis
2007
0098-0331 (Print) Journal Article; In the framework of an evolutionary study, trail pheromones have been studied in the most basal extant termite, Mastotermes darwiniensis (Mastotermitidae), and two other basal termites, the Termopsidae Porotermes adamsoni (Porotermitinae) and Stolotermes victoriensis (Stolotermitinae). Although workers of M. darwiniensis do not walk in single file while exploring a new environment under experimental conditions and are unable to follow artificial trails in 'open field' experiments, they do secrete a trail-following pheromone from their sternal glands. This unique behavior might reflect a primitive function of communication of the sternal gland. The major co…