367 research outputs found
Evaluating Elk Summer Resource Selection and Applications to Summer Range Habitat Management
In much of the west, National Forest lands are managed in part to provide and protect elk (Cervus elaphus) habitat needs, and summer elk habitat is managed with consideration to motorized routes. We evaluated the relative importance of nutritional resources, access routes and other landscape attributes on elk summer resource selection at multiple spatial scales. Resource selection models for 9 different western Montana elk populations, as well are regional models using data from all 9 herds, were compared to determine the applicability of resource selection models for informing habitat management recommendations. We found thatin all populations nutritional resources, best represented using NDVI metrics, were the most important factors associated with elk summer resource selection. Access route disturbances, best represented by the density of all routes (i.e., routes open and closed to motorized use), affected resource selection in all populations, however, the influence of access routes was relatively small as compared to nutritional resources. Regional models of resource selection predicted resource selection across populations better than population-specific models, thus we recommend these types of models be used to inform regional habitat management. Our results suggest that managers should expand the current management paradigm for elk summer habitat to also consider nutritional resources as an important component of elk summer habitat. Time-integrated NDVI, an easily accessible and free data source, may be useful as an assessment tool to identify areas of optimal elk nutrition
New insights into the diverse electronic phases of a novel vanadium dioxide polymorph: A terahertz spectroscopy study
10.1038/srep09182Scientific Reports
First observations of Weddell seals foraging in sponges in Erebus Bay, Antarctica
Attaching cameras to marine mammals allows for first-hand observation of underwater behaviours that may otherwise go unseen. While studying the foraging behaviour of 26 lactating Weddell seals (Leptonychotes weddellii) in Erebus Bay during the austral spring of 2018 and 2019, we witnessed three adults and one pup investigating the cavities of Rossellidae glass sponges, with one seal visibly chewing when she removed her head from the sponge. To our knowledge, this is the first report of such behaviour. While the prey item was not identifiable, some Trematomus fish (a known Weddell seal prey) use glass sponges for shelter and in which to lay their eggs. Three of the four sponge foraging observations occurred around 13:00 (NZDT). Two of the three sponge foraging adults had higher-than-average reproductive rates, and the greatest number of previous pups of any seal in our study population, each having ten pups in 12 years. This is far higher than the study population average of three previous pups (± 2.6 SD). This novel foraging strategy may have evolved in response to changes in prey availability, and could offer an evolutionary advantage to some individuals that exploit prey resources that others may not. Our observations offer new insight into the foraging behaviours of one of the world’s most studied marine mammals. Further research on the social aspects of Weddell seal behaviour may increase our understanding of the extent and mechanisms of behavioural transfer between conspecifics. Research into the specific foraging behaviour of especially successful or experienced breeders is also warranted
The effect of pre-shot routines on golf wedge shot performance
The objective of this study was to examine the effect of pre-performance routines among golfers of low skill and non-golfers on wedge golf shot performance. The intervention strategies involved a physical skill and cognitive-behavioral routine program, as well as a physical skills-only program. Performance was measured on a pre-intervention test, postintervention test, and following a period of time without treatment, and involved wedge shots being played from distances of 40, 50, and 60 m from a target. Participants in this study (N = 68) were assigned to either a golfer or non-golfer group. Participants in the treatment groups attended 2 practice sessions per week during the acquisition phase. A variable practice design was incorporated during the intervention phase. Non-golfers in both intervention groups improved performance following the acquisition phase and maintained these levels of performance in the retention test. Greater improvements in performance were found in the non-golfer physical skills and cognitive-behavioral routine group. The non-golfer physical skills and cognitive-behavioral routine group was the only group to realize significant improvements in performance when comparing initial test performance measures to post-intervention and retention test performance measures across all test distances. Although the golfer treatment groups had consistent improvement in performance measures following the intervention phase, these improvements did not reach statistical significance in the majority of cases
Quantifying fixed individual heterogeneity in demographic parameters: Performance of correlated random effects for Bernoulli variables
Oxaliplatin, 5-fluorouracil/leucovorin and epirubicin as first-line treatment in advanced gastric carcinoma: a phase II study
The association between oxaliplatin and 5-fluorouracil (5-FU) has been extensively reported to improve prognosis of gastric cancer patients. The present study is aimed at evaluating response rate and the toxicity profile of the association with oxaliplatin, 5-FU/lecovorin and epirubicin in gastric cancer patients with locally advanced or metastatic disease. Thirty-six patients have been enrolled and 35 evaluated. The treatment schedule was oxaliplatin (100 mg m−2), 5-FU (400 mg m−2), leucovorin (40 mg m−2) and epirubicin (60 mg m−2) intravenously. administered every 3 weeks for 6 months, for a total of 185 therapy cycles . Response rate and toxicity were assessed according to the international WHO criteria. Every patient received a mean of 5.3 therapy cycles in a day-hospital setting. Sixteen of 35 patients (46%) showed an objective response, two complete response and 14 partial response. Median time to progression was 33 weeks with an overall median survival of 49 weeks. During the study, anaemia grade 3 and neutropenia grade 3 were observed in 9 and 11% of patients respectively. A grade 3 periferic sensorial neuropathy was observed in 6% of patients. No life threatening or cardiac toxicity was recorded. The regimen used showed anticancer activity against gastric carcinoma, a tolerable toxicity profile and excellent patient compliance
Temporal correlations among demographic parameters are ubiquitous but highly variable across species
Temporal correlations among demographic parameters can strongly influence
population dynamics. Our empirical knowledge, however, is very limited regarding
the direction and the magnitude of these correlations and how they vary among
demographic parameters and species’ life histories. Here, we use long-term
demographic data from 15 bird and mammal species with contrasting pace of life
to quantify correlation patterns among five key demographic parameters: juvenile and adult survival, reproductive probability, reproductive success and productivity.
Correlations among demographic parameters were ubiquitous, more frequently
positive than negative, but strongly differed across species. Correlations did not
markedly change along the slow-fast continuum of life histories, suggesting that
they were more strongly driven by ecological than evolutionary factors. As positive
temporal demographic correlations decrease the mean of the long-run population
growth rate, the common practice of ignoring temporal correlations in population
models could lead to the underestimation of extinction risks in most species
A Generalized Allosteric Mechanism for cis-Regulated Cyclic Nucleotide Binding Domains
Cyclic nucleotides (cAMP and cGMP) regulate multiple intracellular processes and are thus of a great general interest for molecular and structural biologists. To study the allosteric mechanism of different cyclic nucleotide binding (CNB) domains, we compared cAMP-bound and cAMP-free structures (PKA, Epac, and two ionic channels) using a new bioinformatics method: local spatial pattern alignment. Our analysis highlights four major conserved structural motifs: 1) the phosphate binding cassette (PBC), which binds the cAMP ribose-phosphate, 2) the “hinge,” a flexible helix, which contacts the PBC, 3) the β2,3 loop, which provides precise positioning of an invariant arginine from the PBC, and 4) a conserved structural element consisting of an N-terminal helix, an eight residue loop and the A-helix (N3A-motif). The PBC and the hinge were included in the previously reported allosteric model, whereas the definition of the β2,3 loop and the N3A-motif as conserved elements is novel. The N3A-motif is found in all cis-regulated CNB domains, and we present a model for an allosteric mechanism in these domains. Catabolite gene activator protein (CAP) represents a trans-regulated CNB domain family: it does not contain the N3A-motif, and its long range allosteric interactions are substantially different from the cis-regulated CNB domains
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