1,167 research outputs found
Marine Birds in the Marginal Ice Zone of the Barents Sea in Late Winter and Spring
We recorded the distribution and abundance of marine birds in the northern Barents Sea from 27 February to 8 March 1987 and from 20 to 31 May 1988. Birds were more abundant in waters associated with pack ice than in open water away from pack ice. Within the pack ice, thick-billed murres (Uria lomvia) were the most commonly encountered birds in both periods. Murre densities in the pack ice north of the zone proximate to the ice edge were positively correlated with distance from the ice edge. Large leads were more frequently occupied by murres than small leads, and had larger numbers of birds present. In spring, we found more birds along a well-defined ice edge than were present either in open water or in leads in the pack ice within 5 nautical miles of the ice edge. Transects along the ice edge revealed little correlation in abundance between species, or within species when coverage was repeated during the same day. We conclude that the birds showed considerable specificity of habitat choice within the habitat divisions that we recognized and that avian patches were of short duration. We need information on the distribution, abundance and movements of prey patches if we are to understand the changing distribution patterns of the birds
Foraging at a front:hydrography, zooplankton, and avian planktivory in the northern Bering Sea
Gangrenous cholecystitis in an asymptomatic patient found during an elective laparoscopic cholecystectomy: a case report
<p>Abstract</p> <p>Introduction</p> <p>Gangrenous cholecystitis is a severe complication of acute cholecystitis. We present an unusual case of gangrenous cholecystitis which was totally asymptomatic, with normal pre-operative parameters, and was discovered incidentally during a laparoscopic cholecystectomy. We have not found any similar cases in the published literature.</p> <p>Case presentation</p> <p>A 79-year-old British Caucasian man presented initially with acute cholecystitis which responded to conservative management. After six weeks he was asymptomatic and had normal blood parameters. An elective laparoscopic cholecystectomy was performed and our patient was found to have a totally gangrenous gall bladder.</p> <p>Conclusion</p> <p>It is important to keep a high index of suspicion for the diagnosis of gangrenous cholecystitis in order to avoid potentially serious complications.</p
Annual and seasonal movements of migrating short-tailed shearwaters reflect environmental variation in sub-Arctic and Arctic waters
The marine ecosystems of the Bering Sea and adjacent southern Chukchi Sea are experiencing rapid changes due to recent reductions in sea ice. Short-tailed shearwaters Puffinus tenuirostris visit this region in huge numbers between the boreal summer and autumn during non-breeding season, and represent one of the dominant top predators. To understand the implications for this species of ongoing environmental change in the Pacific sub-Arctic and Arctic seas, we tracked the migratory movements of 19 and 24 birds in 2010 and 2011, respectively, using light-level geolocators. In both years, tracked birds occupied the western (Okhotsk Sea and Kuril Islands) and eastern (southeast Bering Sea) North Pacific from May to July. In August–September of 2010, but not 2011, a substantial proportion (68 % of the tracked individuals in 2010 compared to 38 % in 2011) moved through the Bering Strait to feed in the Chukchi Sea. Based on the correlation with oceanographic variables, the probability of shearwater occurrence was highest in waters with sea surface temperatures (SSTs) of 8–10 °C over shallow depths. Furthermore, shearwaters spent more time flying when SST was warmer than 9 °C, suggesting increased search effort for prey. We hypothesized that the northward shift in the distribution of shearwaters may have been related to temperature-driven changes in the abundance of their dominant prey, krill (Euphausiacea), as the timing of krill spawning coincides with the seasonal increase in water temperature. Our results indicate a flexible response of foraging birds to ongoing changes in the sub-Arctic and Arctic ecosystems
The effect of systematic pediatric care on neonatal mortality and hospitalizations of infants born with oral clefts
<p>Abstract</p> <p>Background</p> <p>Cleft lip and/or palate (CL/P) increase mortality and morbidity risks for affected infants especially in less developed countries. This study aimed at assessing the effects of systematic pediatric care on neonatal mortality and hospitalizations of infants with cleft lip and/or palate (CL/P) in South America.</p> <p>Methods</p> <p>The intervention group included live-born infants with isolated or associated CL/P in 47 hospitals between 2003 and 2005. The control group included live-born infants with CL/P between 2001 and 2002 in the same hospitals. The intervention group received systematic pediatric care between the 7<sup>th </sup>and 28<sup>th </sup>day of life. The primary outcomes were mortality between the 7<sup>th </sup>and 28<sup>th </sup>day of life and hospitalization days in this period among survivors adjusted for relevant baseline covariates.</p> <p>Results</p> <p>There were no significant mortality differences between the intervention and control groups. However, surviving infants with associated CL/P in the intervention group had fewer hospitalization days by about six days compared to the associated control group.</p> <p>Conclusions</p> <p>Early systematic pediatric care may significantly reduce neonatal hospitalizations of infants with CL/P and additional birth defects in South America. Given the large healthcare and financial burden of CL/P on affected families and the relatively low cost of systematic pediatric care, improving access to such care may be a cost-effective public policy intervention.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00097149">NCT00097149</a></p
Cross reactive cellular immune responses in chickens previously exposed to low pathogenic avian influenza
<p>Abstract</p> <p>Background</p> <p>Avian influenza (AI) infection in poultry can result in high morbidity and mortality, and negatively affect international trade. Because most AI vaccines used for poultry are inactivated, our knowledge of immunity against AI is based largely on humoral immune responses. In fact, little is known about cellular immunity following a primary AI infection in poultry, especially regarding cytotoxic T lymphocytes (CTL’s).</p> <p>Methods</p> <p>In these studies, major histocompatibility complex (MHC)-defined (B<sup>2</sup>/B<sup>2</sup>) chickens were infected with low pathogenic AI (LPAI) H9N2 and clinical signs of disease were monitored over a two weeks period. Splenic lymphocytes from infected and naïve birds were examined for cross reactivity against homologous and heterologous (H7N2) LPAI by ex vivo stimulation. Cellular immunity was determined by cytotoxic lysis of B<sup>2</sup>/B<sup>2</sup> infected lung target cells and proliferation of T cells following exposure to LPAI.</p> <p>Results</p> <p>Infection with H9N2 resulted in statistically significant weight loss compared to sham-infected birds. Splenic lymphocytes derived from H9N2-infected birds displayed lysis of both homologous (H9N2) and heterologous (H7N2) infected target cells, whereas lymphocytes obtained from sham-infected birds did not. T cell proliferation was determined to be highest when exposed to the homologous virus.</p> <p>Conclusions</p> <p>Taken together these data extend the findings that cellular immunity, including CTL’s, is cross reactive against heterologous isolates of AI and contribute to protection following infection.</p
Energy- and flux-budget (EFB) turbulence closure model for the stably stratified flows. Part I: Steady-state, homogeneous regimes
We propose a new turbulence closure model based on the budget equations for
the key second moments: turbulent kinetic and potential energies: TKE and TPE
(comprising the turbulent total energy: TTE = TKE + TPE) and vertical turbulent
fluxes of momentum and buoyancy (proportional to potential temperature).
Besides the concept of TTE, we take into account the non-gradient correction to
the traditional buoyancy flux formulation. The proposed model grants the
existence of turbulence at any gradient Richardson number, Ri. Instead of its
critical value separating - as usually assumed - the turbulent and the laminar
regimes, it reveals a transition interval, 0.1< Ri <1, which separates two
regimes of essentially different nature but both turbulent: strong turbulence
at Ri<<1; and weak turbulence, capable of transporting momentum but much less
efficient in transporting heat, at Ri>1. Predictions from this model are
consistent with available data from atmospheric and lab experiments, direct
numerical simulation (DNS) and large-eddy simulation (LES).Comment: 40 pages, 6 figures, Boundary-layer Meteorology, resubmitted, revised
versio
Suicide amongst psychiatric in-patients who abscond from the ward: a national clinical survey
<p>Abstract</p> <p>Background</p> <p>Suicide prevention by mental health services requires an awareness of the antecedents of suicide amongst high risk groups such as psychiatric in-patients. The goal of this study was to describe the social and clinical characteristics of people who had absconded from an in-patient psychiatric ward prior to suicide, including aspects of the clinical care they received.</p> <p>Methods</p> <p>We carried out a national clinical survey based on a 10-year (1997-2006) sample of people in England and Wales who had died by suicide. Detailed data were collected on those who had been in contact with mental health services in the year before death.</p> <p>Results</p> <p>There were 1,851 cases of suicide by current psychiatric in-patients, 14% of all patient suicides. 1,292 (70%) occurred off the ward. Four hundred and sixty-nine of these patients died after absconding from the ward, representing 25% of all in-patient suicides and 38% of those that occurred off the ward. Absconding suicides were characterised by being young, unemployed and homeless compared to those who were off the ward with staff agreement. Schizophrenia was the most common diagnosis, and rates of previous violence and substance misuse were high. Absconders were proportionally more likely than in-patients on agreed leave to have been legally detained for treatment, non-compliant with medication, and to have died in the first week of admission. Whilst absconding patients were significantly more likely to have been under a high level of observation, clinicians reported more problems in observation due to either the ward design or other patients on the ward.</p> <p>Conclusion</p> <p>Measures that may prevent absconding and subsequent suicide amongst in-patients might include tighter control of ward exits, and more intensive observation of patients, particularly in the early days of admission. Improving the ward environment to provide a supportive and less intimidating experience may contribute to reduced risk.</p
Foot posture influences the electromyographic activity of selected lower limb muscles during gait
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