Simulated drilling noise affects the space use of a large terrestrial mammal

Wildlife is exposed to increasing anthropogenic disturbances related to shale oil and gas extraction in response to rising worldwide demands. As these disturbances increase in intensity and occurrence across the landscape, understanding their impacts is essential for management. On Anticosti Island (Québec, Canada), we equipped six white-tailed deer Odocoileus virginianus with GPS collars taking hourly locations. We then designed a playback experiment by simulating constant drilling noise emitted by generators to which half of the collared deer were exposed for a three-week period. Deer tolerated noise levels up to 70 dB(C). However, the number of locations recorded in areas where the noise was above 70 dB(C) was on average 73% (SE¿18%) lower than before the disturbance, which suggests that deer experienced fine scale functional habitat loss. This loss of habitat occurred up to 200 m from the noise source. The size of home ranges and movement rates did not appear to be affected by the noise disturbance. In addition, during the experiment, deer were able to relocate in areas of their home range where food availability was similar to that of sites used before the disturbance. These results show that drilling noise can affect the habitat use of white-tailed deer. However, future research is needed to better understand the cumulative impacts of shale mining on large mammals, as this study isolated only one of the many disturbances present near mining sites and for a limited perio

Detecting changes in the annual movements of terrestrial migratory species : using the first-passage time to document the spring migration of caribou

Background : Migratory species face numerous threats related to human encroachment and climate change. Several migratory populations are declining and individuals are losing their migratory behaviour. To understand how habitat loss or changes in the phenology of natural processes affect migrations, it is crucial to clearly identify the timing and the patterns of migration. We propose an objective method, based on the detection of changes in movement patterns, to identify departure and arrival dates of the migration. We tested the efficiency of our approach using simulated paths before applying it to spring migration of migratory caribou from the Rivière-George and Rivière-aux-Feuilles herds in northern Québec and Labrador. We applied the First-Passage Time analysis (FPT) to locations of 402 females collected between 1986 and 2012 to characterize their movements throughout the year. We then applied a signal segmentation process in order to segment the path of FPT values into homogeneous bouts to discriminate migration from seasonal range use. This segmentation process was used to detect the winter break and the calving ground use because spring migration is defined by the departure from the winter range and the arrival on the calving ground. Results : Segmentation of the simulated paths was successful in 96% of the cases, and had a high precision (96.4% of the locations assigned to the appropriate segment). Among the 813 winter breaks and 669 calving ground use expected to be detected on the FPT profiles, and assuming that individuals always reduced movements for each of the two periods, we detected 100% of the expected winter breaks and 89% of the expected calving ground use, and identified 648 complete spring migrations. Failures to segment winter breaks or calving ground use were related to individuals only slowing down or performing less pronounced pauses resulting in low mean FPT. Conclusion : We show that our approach, which relies only on the analysis of movement patterns, provides a suitable and easy-to-use tool to study species exhibiting variations in their migration patterns and seasonal range use

Winter severity modulates the benefits of using a habitat temporally uncoupled from browsing

Resources whose abundance is not affected by the density of the consumer population, namely donor-controlled resources, are ubiquitous. Donor-controlled resources can act as food subsidies when they sustain consumer populations at higher densities than what would be predicted without donorcontrolled dynamics. Herbivore populations that have access to food subsidies may reach and maintain high densities, with potential major ecological and economic consequences. A better understanding of the roles of food subsidies on temperate herbivores will likely be achieved by simultaneously taking into account other drivers of demographic variations such as winter severity. Here, we tested the hypothesis that the use of a donor-controlled food resource that may act as a food subsidy, namely balsam fir (Abies balsamea), and winter severity act together to shape the patterns of overwinter mass loss in a large herbivore population (white-tailed deer, Odocoileus virginianus). We monitored weather conditions, diet, habitat use, and mass loss of female deer during two highly contrasted winters. During an exceptionally milder winter, characterized by shallower snow depth and warmer windchill temperatures, female deer shifted their diet toward resources usually covered by snow during typical winters. Surprisingly, the rate of body mass loss remained similar during the milder and the harsher winter. The rate of body mass loss rather decreased with the use of balsam fir stands during the harsher winter, but increased with that same variable during the milder winter. Our study revealed that deer can alleviate overwinter mass loss by using a donor-controlled habitat type temporally uncoupled from browsing, but that this benefit is climate dependent. This study represents an additional step to address the largely unexplored concept of how temporal uncoupling between resources and consumer dynamics may contribute to sustain consumer populations at higher densities than predicted without considering donor-controlled dynamics

\u3ci\u3eN\u3c/i\u3e\u3csup\u3e5\u3c/sup\u3e-Phosphonoacetyl-L-ornithine (PALO): A convenient synthesis and investigation of influence on regulation of amino acid biosynthetic genes in \u3ci\u3eSaccharomyces cerevisiae\u3c/i\u3e

A scalable four-step synthesis of the ornithine transcarbamylase inhibitor N5-phosphonoacetyl-L-ornithine (PALO) is achieved through boroxazolidinone protection of ornithine. Investigations in the model organism Saccharomyces cerevisiae found that, in contrast to a previous report, PALO did not influence growth rate or expression of genes involved in arginine metabolism

m7824 msb0011359c a bifunctional fusion protein targeting pd l1 and tgf β in patients with post platinum esophageal adenocarcinoma eac preliminary results from a phase i cohort

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Novel Amphiphilic Cyclobutene and Cyclobutane \u3ci\u3ecis\u3c/i\u3e-C18 Fatty Acid Derivatives Inhibit \u3ci\u3eMycobacterium avium\u3c/i\u3e subsp. \u3ci\u3eparatuberculosis\u3c/i\u3e Growth

Mycobacterium avium subspecies paratuberculosis (Map) is the etiologic agent of Johne’s disease in ruminants and has been associated with Crohn’s disease in humans. An effective control of Map by either vaccines or chemoprophylaxis is a paramount need for veterinary and possibly human medicine. Given the importance of fatty acids in the biosynthesis of mycolic acids and the mycobacterial cell wall, we tested novel amphiphilic C10 and C18 cyclobutene and cyclobutane fatty acid derivatives for Map inhibition. Microdilution minimal inhibitory concentrations (MIC) with 5 or 7 week endpoints were measured in Middlebrook 7H9 base broth media. We compared the Map MIC results with those obtained previously with Mycobacterium tuberculosis and Mycobacterium smegmatis. Several of the C18 compounds showed moderate effcacy (MICs 392 to 824 μM) against Map, while a higher level of inhibition (MICs 6 to 82 μM) was observed for M. tuberculosis for select analogs from both the C10 and C18 groups. For most of these analogs tested in M. smegmatis, their effcacy decreased in the presence of bovine or human serum albumin. Compound 5 (OA-CB, 1-(octanoic acid-8-yl)-2-octylcyclobutene) was identified as the best chemical lead against Map, which suggests derivatives with better pharmacodynamics may be of interest for evaluation in animal models

Assessment of human resources management practices in Lebanese hospitals

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