62 research outputs found

    Effects of Weather on Reproductive Success of Birds at Churchill, Manitoba

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    Describes the effect of a severe wind and rain storm, 8 July 1965, on passerine bird nestlings in this area. Mortality from exposure was high: there was little evidence of starvation. The weather did not effect nests with eggs only. Non-passerine species appeared largely unaffected by the storm. The altricial condition of passerine young may account for paucity of arctic passerine species.Effets du temps sur la reproduction des oiseaux à Churchill, Manitoba. Les auteurs étudient les effets d'un vent violent et d'une forte pluie d'orage du début juillet 1965 sur les nichées d'oiseaux de la région de Churchill, Manitoba, et le rôle, peut-être déterminant, du temps dans la composition de l'avifaune arctique

    Temperature Regulation and the Constraints of Climate in the Eared Grebe

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    Eared Grebes (Podiceps nigricollis) encounter a variety of climatic regimes in their annual cycle. The most dramatic occur while on staging areas in autumn. We investigated the thermoregulatory abilities of the Eared Grebe to determine how they coped with these climate changes during staging. The basal metabolic rate (BMR) was higher than predicted. Mass-specific BMR was 1.212 mL O2/g·h for birds averaging 317 g. The thermoneutral zone is wide and extended from 15°C to 38°C. Minimal thermal conductance and average body temperature were not unusual. We conclude that Eared Grebes live most of the year under thermoneutral conditions and that food availability, not temperature extremes, determines the timing of their winter migration

    Total Body Water and Body Composition in Phalaropes and Other Birds

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    Contrary to some reviews, total body water (TBW) may fall below the expected value of about 65% in birds if measured as a percentage of total body mass. However, water constitutes a relatively stable proportion (659%-70%) of body composition when measured as a percentage of lean body mass (LBM). We demonstrate this by using data from two migratory phalaropes (Phalaropus tricolor and Phalaropus lobatus), which exhibit inverse relationships between TBW and body mass and between TBW and fat content. As the phalaropes fatten before migration, lipids increase but not at the expense of water, which also increases with gains in lean tissue. The gain in lean dry mass with body size is also correlated with migration. Because absolute water increases with body mass, TBW is a poor measure of hydration; however, because of the inverse relationship between TBW and fat, TBW can predict body fat accurately if a calibration curve is first generated. We provide equations that predict fat content in both species of phalaropes suggest that water normally be reported not as TBW (a percentage of total body mass) but preferably as lean body water (LBW, a percentage of lean body mass). In the absence of quantitative estimates off at, we suggest that water be communicated in absolute amount, preferably with some estimate of condition (fat)

    é™°èŽ–ç™Œăƒ‹ć°±ăƒ†

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    Eared grebe (D-15) downed in Dugway, UT, during Spring migration towards Great Salt Lake. After segmentation in Mimics, jpg files were exported with fat tissue highlighted. Images allowed landmark identification and slice range for each ROI (region of interest) - chest, thorax and abdomen. Also, a txt file with fat area measurement for each slice was generated. Depot fat measurement was calculated by matching ROI slice range and fat values

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    A REVIEW OF NELSON\u27S GULL LARUS-NELSONI

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    Volume: 107Start Page: 86End Page: 9

    D27 fat tissue segmentation

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    Eared grebe (D-27) downed in Dugway, UT, during Spring migration towards Great Salt Lake. After segmentation in Mimics, jpg files were exported with fat tissue highlighted. Images allowed landmark identification and slice range for each ROI (region of interest) - chest, thorax and abdomen. Also, a txt file with fat area measurement for each slice was generated. Depot fat measurement was calculated by matching ROI slice range and fat values

    Data from: Rapid mobilization of abdominal fat in migrating eared grebes

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    Eared grebes Podiceps nigricollis, like shorebirds and other long-distance migrants, lay down large amounts of fat to power their journeys. To investigate the pattern of how fat and soft tissue might be mobilized, we used grebes killed in migration and applied computed tomography to reconstruct how stores in the chest, thorax, and abdomen were reduced as body weight decreased. Fat and soft tissue were each mobilized at a constant rate through the entire migration. Fat stores in birds embarking on migration were greater in the abdomen than thorax than chest. In contrast to previous studies indicating that abdominal fat was mobilized first, we found that fat from all areas was mobilized concurrently, but that abdominal fat was catabolized at a greater rate. We suggest why this pattern might be advantageous, consider whether inter-depot differences in fat composition might be involved, and note possible energetic consequences. Whether our findings pertain to other obese or long distance migrants remains to be determined
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