868 research outputs found
Experimental Facilities Development
This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440
Splanchnic oxygen saturation during reoxygenation with 21% or 100% O-2 in newborn piglets
Background Increasing evidence recognizes the harm of excess oxygen to lungs, eyes, and brain of preterm infants, but not yet to the intestine. We assessed changes in splanchnic oxygenation during reoxygenation with 21% compared to 100% O-2 in a newborn piglet model of perinatal asphyxia. Methods We randomized 25 piglets to control or intervention. Intervention groups underwent global hypoxia until acidosis and hypotension occurred. Piglets were reoxygenated for 30 min with 21% or 100% O-2 and observed for 9 h. We continuously measured regional splanchnic oxygen saturation (r(s)SO(2)) using near-infrared spectroscopy (NIRS). We calculated mean r(s)SO(2) and r(s)CoVar (as SD/mean). We measured PaO2 and SaO(2), sampled from the right carotid artery. Results Reoxygenation after global hypoxia restored r(s)SO(2). Reoxygenation with 100% O-2 increased r(s)SO(2) to values significantly higher than baseline. In intervention groups, r(s)CoVar decreased during observation compared to baseline. We found a correlation between r(s)SO(2) and PaO2 (r = 0.420, P < 0.001) and between r(s)SO(2) and SaO(2) (r = 0.648, P < 0.001) in pooled data from the entire experiment. Conclusion Reoxygenation after global hypoxia improves splanchnic oxygenation, but is associated with reduced variability of r(s)SO(2). Reoxygenation with 100% O-2 exposes the intestine to hyperoxia. Splanchnic NIRS is able to detect intestinal hypoxia and hyperoxia. Impact Splanchnic oxygenation improves during reoxygenation after global hypoxia, though reoxygenation with 100% O2 exposes the intestine to hyperoxia. Decreased variability of splanchnic oxygenation several hours after hypoxia and reoxygenation seems to be independent of the resuscitation strategy, and may indicate intestinal injury. Splanchnic NIRS monitoring was able to detect intestinal hypoxia and exposure to hyperoxia, as evidenced by a strong correlation between splanchnic oxygenation and arterial oxygen content
Recruiting medical groups for research: relationships, reputation, requirements, rewards, reciprocity, resolution, and respect
BACKGROUND: In order to conduct good implementation science research, it will be necessary to recruit and obtain good cooperation and comprehensive information from complete medical practice organizations. The goal of this paper is to report an effective example of such a recruitment effort for a study of the organizational aspects of depression care quality. METHODS: There were 41 medical groups in the Minnesota region that were eligible for participation in the study because they had sufficient numbers of patients with depression. We documented the steps required to both recruit their participation in this study and obtain their completion of two questionnaire surveys and two telephone interviews. RESULTS: All 41 medical groups agreed to participate and consented to our use of confidential data about their care quality. In addition, all 82 medical directors and quality improvement coordinators completed the necessary questionnaires and interviews. The key factors explaining this success can be summarized as the seven R's: Relationships, Reputation, Requirements, Rewards, Reciprocity, Resolution, and Respect. CONCLUSION: While all studies will not have all of these factors in such good alignment, attention to them may be important to other efforts to add to our knowledge of implementation science
Genomic breeding value estimation using nonparametric additive regression models
Genomic selection refers to the use of genomewide dense markers for breeding value estimation and subsequently for selection. The main challenge of genomic breeding value estimation is the estimation of many effects from a limited number of observations. Bayesian methods have been proposed to successfully cope with these challenges. As an alternative class of models, non- and semiparametric models were recently introduced. The present study investigated the ability of nonparametric additive regression models to predict genomic breeding values. The genotypes were modelled for each marker or pair of flanking markers (i.e. the predictors) separately. The nonparametric functions for the predictors were estimated simultaneously using additive model theory, applying a binomial kernel. The optimal degree of smoothing was determined by bootstrapping. A mutation-drift-balance simulation was carried out. The breeding values of the last generation (genotyped) was predicted using data from the next last generation (genotyped and phenotyped). The results show moderate to high accuracies of the predicted breeding values. A determination of predictor specific degree of smoothing increased the accuracy
Arctic smoke ? record high air pollution levels in the European Arctic due to agricultural fires in Eastern Europe
International audienceIn spring 2006, the European Arctic was abnormally warm, setting new historical temperature records. During this warm period, smoke from agricultural fires in Eastern Europe intruded into the European Arctic and caused the most severe air pollution episodes ever recorded there. This paper confirms that biomass burning (BB) was indeed the source of the observed air pollution, studies the transport of the smoke into the Arctic, and presents an overview of the observations taken during the episode. Fire detections from the MODIS instruments aboard the Aqua and Terra satellites were used to estimate the BB emissions. The FLEXPART particle dispersion model was used to show that the smoke was transported to Spitsbergen and Iceland, which was confirmed by MODIS retrievals of the aerosol optical depth (AOD) and AIRS retrievals of carbon monoxide (CO) total columns. Concentrations of halocarbons, carbon dioxide and CO, as well as levoglucosan and potassium, measured at Zeppelin mountain near Ny Ålesund, were used to further corroborate the BB source of the smoke at Spitsbergen. The ozone (O3) and CO concentrations were the highest ever observed at the Zeppelin station, and gaseous elemental mercury was also enhanced. A new O3 record was also set at a station on Iceland. The smoke was strongly absorbing ? black carbon concentrations were the highest ever recorded at Zeppelin ?, and strongly perturbed the radiation transmission in the atmosphere: aerosol optical depths were the highest ever measured at Ny Ålesund. We furthermore discuss the aerosol chemical composition, obtained from filter samples, as well as the aerosol size distribution during the smoke event. Photographs show that the snow at a glacier on Spitsbergen became discolored during the episode and, thus, the snow albedo was reduced. Samples of this polluted snow contained strongly enhanced levels of potassium, sulphate, nitrate and ammonium ions, thus relating the discoloration to the deposition of the smoke aerosols. This paper shows that, to date, BB has been underestimated as a source of aerosol and air pollution for the Arctic, relative to emissions from fossil fuel combustion. Given its significant impact on air quality over large spatial scales and on radiative processes, the practice of agricultural waste burning should be banned in the future
“I h 8 u”: Findings from a five-year study of text and e-mail bullying
Copyright @ 2010 British Educational Research Association. The final version of this article is available at the link below.This study charts reports of nasty or threatening text and e-mail messages received by students in academic years 7 and 8 (11-13 years of age) attending 13 secondary schools in the North of England between 2002-2006. Annual surveys were undertaken on behalf of the local education authority (LEA) to monitor bullying. Results indicated that, over five years, the number of pupils receiving one or more nasty or threatening text messages or e-mails increased significantly, particularly among girls. However, receipt of frequent nasty or threatening text and e-mail messages remained relatively stable. For boys, being a victim of direct-physical bullying was associated with receiving nasty or threatening text and e-mail messages; for girls it was being unpopular among peers. Boys received more hate-related messages and girls were primarily the victims of name-calling, Findings are discussed with respect to theoretical and policy developments, and recommendations for future research are offered
People of the British Isles: preliminary analysis of genotypes and surnames in a UK control population
There is a great deal of interest in fine scale population structure in the UK, both as a signature of historical immigration events and because of the effect population structure may have on disease association studies. Although population structure appears to have a minor impact on the current generation of genome-wide association studies, it is likely to play a significant part in the next generation of studies designed to search for rare variants. A powerful way of detecting such structure is to control and document carefully the provenance of the samples involved. Here we describe the collection of a cohort of rural UK samples (The People of the British Isles), aimed at providing a well-characterised UK control population that can be used as a resource by the research community as well as
providing fine scale genetic information on the British population. So far, some 4,000 samples have been collected, the majority of which fit the criteria of coming from a rural area and having all four grandparents from approximately the same area. Analysis of the first 3,865 samples that have been geocoded indicates that 75% have
a mean distance between grandparental places of birth of 37.3km, and that about 70% of grandparental places of birth can be classed as rural. Preliminary genotyping of 1,057
samples demonstrates the value of these samples for investigating fine scale population structure within the UK, and shows how this can be enhanced by the use of surnames
Experimental Facilities Development
This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440
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