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Presents a theoretical model for the noise properties of n[sup +]nn[sup +] diodes in the drift-diffusion framework. Incorporation of both the drift and diffusive parts of the current under inhomogeneous and hot-carrier conditions; Characterization of the noise properties of the diodes.

On account of low resistivity contacts and of a newly developed device, the investigation of the 1/f noise at high drain current has been made possible. Therefore, it has been acknowledged that the correlated carrier number and mobility fluctuations model were not able to satisfactorily explain the 1/f noise within this particular region. Indeed, the fundamental mobility fluctuations were also generating 1/f fluctuations and were furthermore, taking over at high biases. It eventually came to light that the fundamental mobility fluctuations along with the sole oxide charge fluctuations were accurately modeling the noise all over the measurement range, allowing us to notice that the fundamental mobility fluctuations were generating the same amount of 1/f fluctuations as the induced mobility added to the cross correlated ones. [ABSTRACT FROM AUTHOR]

We used ancient DNA techniques to amplify mitochondrial DNA fragments [cytochrome b (cyt b) and control region (CR)] from four museum specimens that represent, to our knowledge, the last testimony of the introduction of – now extinct – mongooses in Italy. We assessed the identity, origin and genetic variability of Italian mongooses using a species-level assignation Bayesian approach and haplotype network analysis. The genetic diversity (cyt b and CR) among Italian individuals was null. The cyt b sequences from the four museum specimens clearly established the Indian grey mongoose Herpestes edwardsii as the species having been introduced in Italy in the mid-XXth century. The latter had at least been released twice within a period of 10 years (Circeo NP and Capalbio, c. 200 km northward), probably from the same captive stock of the Giardino Zoologico di Roma. Assessment of genetic variability and haplotype network including native representatives of H. edwardsii suggested that the introduced pool likely originated from Pakistan or India. It appears that a combination of deleterious factors including low genetic diversity, restricted range and nonadaptation to western Palaearctic winter conditions is responsible for the extinction of the species in Italy. However, the lack of knowledge on the life-history traits and population dynamics of H. edwardsii prevents from further discussion of the factors that likely promoted its extinction process. [ABSTRACT FROM AUTHOR]

The common genet (Genetta genetta) is a small carnivoran that was probably introduced from Maghreb into south-western Europe. We reassessed its easternmost European distribution from 110 - mostly new - data collected in south-eastern France and Italy, and tested for potential habitat selection, to finally re-evaluate the role of the Rhône as a geographic barrier against eastward migrations. The species was more frequent in river valleys, wetlands and low-mountainous areas (south-eastern France), but also occurred in high-mountainous zones at the French-Italian border. Our results evidenced a significant increase of records (13-fold the number of occurrences previously known) and an apparent absence of habitat selection by the common genet, suggesting a recent, natural spread from the right bank of the Rhône through a zone of ∼30 km with artificial bridges. We finally provide a synthetic, re-assessed distribution map of the common genet in France and Italy, combining 4317 occurrences from French national databases and the 110 records collected herein. [ABSTRACT FROM AUTHOR]

The conservation of poorly known species is difficult because of incomplete knowledge on their biology and distribution. We studied the contribution of two ecological niche modelling tools, the Genetic Algorithm for Rule-set Prediction (GARP) and maximum entropy (Maxent), in assessing potential ranges and distributional connectivity among 12 of the least known African and Asian viverrids. The level of agreement between GARP and Maxent predictions was low when < 15 occurrences were available, probably indicating a minimum number below that necessary to obtain models with good predictive power. Unexpectedly, our results suggested that Maxent extrapolated more than GARP in the context of small sample sizes. Predictions were overlapped with current land use and location of protected areas to estimate the conservation status of each species. Our analyses yielded range predictions generally contradicting with extents of occurrence established by the IUCN. We evidenced a high level of disturbance within predicted distributions in West and East Africa, Sumatra, and South-East Asia, and identified within West African degraded lowlands four relatively preserved areas that might be of prime importance for the conservation of rainforest taxa. Knowing whether these species of viverrids may survive in degraded or alternative habitats is of crucial importance for further conservation planning. The level of coverage of species suitable ranges by existing and proposed IUCN reserves was low, and we recommend that the total surface of protected areas be substantially increased on both continents. [ABSTRACT FROM AUTHOR]

Abstract: Natural history collections are crucial resources for conservation biology, particularly given the development of the ecological niche modeling (ENM) approach. We combined ENM with taxonomic investigations to address ecological, geographic, and phenotypic variation in the poorly known central African rainforest genets (Genetta cristata, Genetta servalina, Genetta victoriae) to provide new insights into their conservation status. Taxonomic identification was based on four discrete morphological characters. ENMs were developed using the Genetic Algorithm for Rule-Set Prediction (GARP), 10 environmental data layers and 310 georeferenced localities extracted from 667 museum specimens and 22 literature sources. Re-assessed taxonomic identifications allowed us to expand significantly the known range and ecological limits of the three genets. We suggested limited hybridization between G. cristata and G. servalina, in a zone of sympatry likely to cover central Cameroon, northwestern Gabon and Congo. ENM showed that almost all known occurrences were connected geographically by suitable ecological conditions, suggesting continuous potential distributions between supposedly isolated populations of the three genets. Our investigations indicated that G. cristata is distinct from G. servalina in morphology, geographic ranges and ecological niches, indicating species status for G. cristata, which, as such, should be the subject of appropriate conservation attention. Areas of predicted connectivity and actual zones of occurrence falling outside current forest cover should be surveyed to re-assess the status of the rainforest genets. Our study shows that combining ENM and taxonomic investigations can substantially improve data utilization from natural history collections, especially in the case of poorly known species. [Copyright &y& Elsevier]

ABSTRACT The rare Johnston’s Genet (Genetta johnstoni ) is one of the least known small carnivores inhabiting the West African rain forest. Some newly discovered specimens collected from the field (Guinea and Ivory Coast) and several rediscovered specimens resulting from reinvestigating collections, have permitted us to reconsider the distribution of the species. Coupled with a bibliographic review and a census of specimens kept in public collections, a reassessed distribution map is proposed, extending the previous estimated range 400 km to the West (Kolenté Plates, Guinea) and more than 600 km to the East (Tarkwa, Ghana). The majority of collected specimens have come from the inland forests of northern Liberia and south-eastern Guinea, while the surroundings of Mt. Nimba also support numbers of this species. We suggest that the supposed restriction of G. johnstoni to rain forest be re-evaluated because a specimen was collected in a region of moist woodlands and savannah (Kolenté Plateau). With regard to these new distributional data, conservation implications for the whole Upper Guinean block population are discussed. [ABSTRACT FROM AUTHOR]

Microsatellite markers were developed to assess population structure and patterns of translocation in the introduced European common genet ( Genetta genetta). Primer pairs were designed for 60 microsatellite sequences enriched for CA, GA, CATC and TAGA repeat motifs. Eleven loci that proved to be polymorphic were genotyped in 33 individuals from southwestern France. The number of alleles per locus and observed heterozygosities varied from three to seven and from 0.2121 to 0.7576, respectively. One locus (B103) showed significant departure from Hardy–Weinberg equilibrium, probably due to the presence of null alleles. Tests of linkage disequilibrium did not detect significant associations among loci. [ABSTRACT FROM AUTHOR]

For most Ivorian regions quantitative data on the exploitation of bushmeat by local communities are scarce. We studied hunting patterns around Dassioko Sud Forest Reserve, a remnant coastal forest in south-eastern Côte d'Ivoire, through a 6-month survey of nine restaurants, in three villages surrounding the Reserve. We collected quantitative and qualitative data on the bushmeat brought to restaurants, as well as the final price for which it was sold. We calculated mean prices over the study period and extrapolated to the whole year. A total of 376 mammals (98%) and eight reptiles (2%) were sold in the restaurants surveyed. Rodents and small antelopes represented 74% of the mammals sold, probably reflecting the fact that reproductive strategists persist more successfully in heavily hunted and/or agricultural landscapes, such as the area around the Reserve. Our conservative estimate of the total biomass of bushmeat harvested annually around the Reserve is c. 40,428.03 kg (c. 11,886 animals), with a monetary value of c. FCFA 47,728,516 (c. USD 93,485.75 ), yielding an annual income of c. USD10,387.31 per person, which exceeds the mean annual income of cocoa farmers (FCFA 466,032/USD 932) more than tenfold. Although the sustainability of the bushmeat trade in the surveyed area remains unknown, we showed that hunters predominantly used cable snares, the Reserve was significantly affected by hunting activities (c. 53% of the bushmeat originated there), and larger mammalian species had been extirpated. A lack of effective protection exposes the Reserve to multiple illegal activities, including hunting, a situation exacerbated by the political crisis in 2010. [ABSTRACT FROM PUBLISHER]