University of Vermont

About: University of Vermont is a education organization based out in Burlington, Vermont, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 17592 authors who have published 38251 publications receiving 1609874 citations. The organization is also known as: UVM & University of Vermont and State Agricultural College.

Sufficient sampling for asymptotic minimum species richness estimators

Abstract: Biodiversity sampling is labor intensive, and a substantial fraction of a biota is often represented by species of very low abundance, which typically remain undetected by biodiversity surveys. Statistical methods are widely used to estimate the asymptotic number of species present, including species not yet detected. Additional sampling is required to detect and identify these species, but richness estimators do not indicate how much sampling effort (additional individuals or samples) would be necessary to reach the asymptote of the species accumulation curve. Here we develop the first statistically rigorous nonparametric method for estimating the minimum number of additional individuals, samples, or sampling area required to detect any arbitrary proportion (including 100%) of the estimated asymptotic species richness. The method uses the Chao1 and Chao2 nonparametric estimators of asymptotic richness, which are based on the frequencies of rare species in the original sampling data. To evaluate the performance of the proposed method, we randomly subsampled individuals or quadrats from two large biodiversity inventories (light trap captures of Lepidoptera in Great Britain and censuses of woody plants on Barro Colorado Island [BCI], Panama). The simulation results suggest that the method performs well but is slightly conservative for small sample sizes. Analyses of the BCI results suggest that the method is robust to nonindependence arising from small-scale spatial aggregation of species occurrences. When the method was applied to seven published biodiversity data sets, the additional sampling effort necessary to capture all the estimated species ranged from 1.05 to 10.67 times the original sample (median approximately equal to 2.23). Substantially less effort is needed to detect 90% of the species (0.33-1.10 times the original effort; median approximately equal to 0.80). An Excel spreadsheet tool is provided for calculating necessary sampling effort for either abundance data or replicated incidence data.

Does serving the community also serve the company? Using organizational identification and social exchange theories to understand employee responses to a volunteerism programme

Abstract: Little is known about how employees might respond to their company's socially responsible business practices. Hypotheses derived from organizational identification and social exchange theories were tested to explain why employees (N=162) may respond positively to their company's volunteerism programme, a programme through which employees could spend time volunteering during their paid work hours. Support was found for mediated effects suggesting that employees' attitude towards the volunteerism programme ultimately predicted outcomes (e.g., intentions to stay) through its effect on organizational identification. Results also showed that exchange ideology moderated the effects of volunteer-programme attitudes on supervisor-reported organizational citizenship behaviour measured 6 months later, suggesting that some employees reciprocate the benefits they receive from a volunteerism programme. The implications of these findings are discussed for theory and research, and for leveraging volunteerism programmes and other socially responsible business practices to benefit companies and their employees.

Association between Intraoperative Blood Transfusion and Mortality and Morbidity in Patients Undergoing Noncardiac Surgery

Abstract: Background: The impact of intraoperative erythrocyte transfusiononoutcomesofanemicpatientsundergoingnoncardiacsurgeryhasnotbeenwellcharacterized.Theobjective of this study was to examine the association between blood transfusion and mortality and morbidity in patients with severeanemia(hematocritlessthan30%)whoareexposedto one or two units of erythrocytes intraoperatively. Methods: Thiswasaretrospectiveanalysisoftheassociationof blood transfusion and 30-day mortality and 30-day morbidity in 10,100 patients undergoing general, vascular, or orthopedic surgery. We estimated separate multivariate logistic regression models for 30-day mortality and for 30-day complications. Results: Intraoperative blood transfusion was associated with an increased risk of death (odds ratio [OR], 1.29; 95% CI, 1.03–1.62). Patients receiving an intraoperative transfusion were more likely to have pulmonary, septic, wound, or thromboembolic complications, compared with patients not receiving an intraoperative transfusion. Compared with patients who were not transfused, patients receiving one or two units of erythrocytes were more likely to have pulmonary complications (OR, 1.76; 95% CI, 1.48–2.09), sepsis (OR, 1.43; 95% CI, 1.21–1.68), thromboembolic complications (OR, 1.77; 95% CI, 1.32–2.38), and wound complications (OR, 1.87; 95% CI, 1.47–2.37). Conclusions: Intraoperative blood transfusion is associated with a higher risk of mortality and morbidity in surgical patients with severe anemia. It is unknown whether this association is due to the adverse effects of blood transfusion or is, instead, the result of increased blood loss in the patients receiving blood.