Detection of non-consumptive effects of predation and intraspecific aggression in fire salamander larvae: Environmental issues

The identification of injury causes may reveal important insights on the factors that influence intra and interspecific predation pressures. In this study we evaluated the proportion of injuries occurring in fire salamander larvae (Salamandra salamandra) in caves and epigean springs to understand the factors determining non-consumptive effects that may affect larval survival. We surveyed 25 sites (13 cave pools, 12 spring pools) during the day. We applied two consecutive removal samplings to collect fire salamander larvae and examined every removed larva to detect if it had injuries and we evaluated the proportion of the injured larvae on the total number of collected larvae. For each site we recorded different environmental variables including predator occurrence and prey density. The proportion of injured larvae was significantly linked only to predators occurrence. Our results show that interspecific predation pressure is a major source of non-consumptive effects that may affect larval survival Overall, our study underlines the role that environmental features may play on the non-consumptive effects of selective pressures that affect larval survival. Predator occurrence determines the levels of non-consumptive effects and larval survival across their developmental cycle. These results deriving from a field survey could furnish useful insights for further experimental studies

Comparative Distribution of Enterococcus Species in Feces and Clinical-samples

The species distribution of 341 enterococci recovered from faecal samples of 250 patients and healthy individuals was compared with 574 clinical isolates. Species other than E. faecalis and E. faecium accounted for only 2.4 per cent of the clinical, but for 36.9 per cent of the faecal isolates. Such species were present in more than half the positive faecal samples. In contrast to its distribution in clinical isolates, E. faecium was slightly more represented in stools than E. faecalis. Species distribution was not markedly different in faecal isolates from hospitalised patients or healthy persons, but almost no resistance to antibiotics was found in healthy individuals' strains. Ampicillin resistance was observed in 51.5 per cent of the clinical E. faecium strains

Emergence of high-level resistance to glycopeptides in Enterococcus gallinarum and Enterococcus casseliflavus.

Enterococcus gallinarum BM4231 and Enterococcus casseliflavus BM4232, isolated from the feces of a patient under oral therapy with vancomycin, were resistant to high levels of vancomycin (MICs of > 256 micrograms/ml) and teicoplanin (MICs of 128 and 64 micrograms/ml, respectively). This phenotype is new for these bacterial species that are naturally resistant to low levels of vancomycin and appears to be due to in vivo acquisition of plasmid pIP218 carrying the vanA gene cluster

Etude anatomique et extensométrique concernant la collerette d'appui et le manche de la prothèse: Base de la conception d'une prothèse anatomique

info:eu-repo/semantics/publishe

Data from: Reduction of baseline corticosterone secretion correlates with climate warming and drying across wild lizard populations

1. Climate change should lead to massive loss of biodiversity in most taxa but the detailed physiological mechanisms underlying population extinction remain largely elusive so far. In vertebrates, baseline levels of hormones such as glucocorticoids (GCs) may be indicators of population state since their secretion to chronic stress can impair survival and reproduction. However, the relationship between GC secretion, climate change and population extinction risk remains unclear. 2. In this study we investigated whether levels of baseline corticosterone (the main GCs in reptiles) correlate with environmental conditions and associated extinction risk across wild populations of the common lizard Zootoca vivipara. 3. First, we performed a cross-sectional comparison of baseline corticosterone levels along an altitudinal gradient among 14 populations. Then, we used a longitudinal study in 8 populations to examine the changes in corticosterone levels following the exposure to a heat wave period. 4. Unexpectedly, baseline corticosterone decreased with increasing thermal conditions at rest in females, and was not correlated with extinction risk. In addition, baseline corticosterone levels decreased after exposure to an extreme heat wave period. This seasonal corticosterone decrease was more pronounced in populations without access to standing water. 5. We suggest that low basal secretion of corticosterone may entail down-regulating activity levels and limit exposure to adverse climatic conditions, especially to reduce water loss. These new insights suggest that rapid population decline might be preceded by a down-regulation of the corticosterone secretion

Environmental conditions and male quality traits simultaneously explain variation of multiple colour signals in male lizards

enThis link goes to a English sectionfrThis link goes to a French section Male lizards often display multiple pigment-based and structural colour signals which may reflect various quality traits (e.g. performance, parasitism), with testosterone (T) often mediating these relationships. Furthermore, environmental conditions can explain colour signal variation by affecting processes such as signal efficacy, thermoregulation and camouflage. The relationships between colour signals, male quality traits and environmental factors have often been analysed in isolation, but simultaneous analyses are rare. Thus, the response of multiple colour signals to variation in all these factors in an integrative analysis remains to be investigated. Here, we investigated how multiple colour signals relate to their information content, examined the role of T as a potential mediator of these relationships and how environmental factors explain colour signal variation. We performed an integrative study to examine the covariation between three colour signals (melanin-based black, carotenoid-based yellow–orange and structural UV), physiological performance, parasitism, T levels and environmental factors (microclimate, forest cover) in male common lizards Zootoca vivipara from 13 populations. We found that the three colour signals conveyed information on different aspects of male condition, supporting a multiple message hypothesis. T influenced only parasitism, suggesting that T does not directly mediate the relationships between colour signals and their information content. Moreover, colour signals became more saturated in forested habitats, suggesting an adaptation to degraded light conditions, and became generally brighter in mesic conditions, in contradiction with the thermal melanism hypothesis. We show that distinct individual quality traits and environmental factors simultaneously explain variations of multiple colour signals with different production modes. Our study therefore highlights the complexity of colour signal evolution, involving various sets of selective pressures acting at the same time, but in different ways depending on colour production mechanism