104 research outputs found
Degree of multicollinearity and variables involved in linear dependence in additive-dominant models
The objective of this work was to assess the degree of multicollinearity and to identify the variables involved in linear dependence relations in additive-dominant models. Data of birth weight (n=141,567), yearling weight (n=58,124), and scrotal circumference (n=20,371) of Montana Tropical composite cattle were used. Diagnosis of multicollinearity was based on the variance inflation factor (VIF) and on the evaluation of the condition indexes and eigenvalues from the correlation matrix among explanatory variables. The first model studied (RM) included the fixed effect of dam age class at calving and the covariates associated to the direct and maternal additive and non-additive effects. The second model (R) included all the effects of the RM model except the maternal additive effects. Multicollinearity was detected in both models for all traits considered, with VIF values of 1.03 - 70.20 for RM and 1.03 - 60.70 for R. Collinearity increased with the increase of variables in the model and the decrease in the number of observations, and it was classified as weak, with condition index values between 10.00 and 26.77. In general, the variables associated with additive and non-additive effects were involved in multicollinearity, partially due to the natural connection between these covariables as fractions of the biological types in breed composition
The influence of spatial contrast processing on human stereoscopic vision
SIGLEAvailable from British Library Document Supply Centre- DSC:D95130 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
A pilot study to assess tolerability of early enteral nutrition via esophagostomy tube feeding in dogs with severe acute pancreatitis
Background: The putative role of the gut in amplification of systemic inflammation in acute pancreatitis is gaining credence, and intraluminal nutrition has been shown to decrease inflammation in experimental models of pancreatitis. Prepyloric feeding often is used in people with acute pancreatitis, but has not been evaluated in dogs. Hypothesis: Early intervention with enteral nutrition (EN) delivered proximal to the pylorus will be well tolerated in dogs with acute pancreatitis and provide justification for further larger trials. Animals: Ten dogs with severe acute pancreatitis in an open-label, prospective pilot study. Methods: Dogs were treated with plasma transfusion and standard care, and then consecutively assigned to receive either EN via esophagostomy tube feeding or parenteral nutrition (PN). Outcome was used to determine optimal study size for future studies, and complications were compared between the 2 groups. Results: A significantly greater number of vomiting or regurgitating episodes occurred in dogs receiving PN. The dogs receiving EN did not demonstrate any noticeable postprandial pain. There were more catheter-related complications in the PN group. There was no difference in outcome between the 2 treatments, and 43 dogs for each treatment would be required in future studies to determine a difference in outcome. Conclusions and Clinical Relevance: Early EN delivered proximal to the pylorus is well tolerated in dogs with severe pancreatitis and resulted in fewer complications than PN. Prospective trials in a larger cohort are justified to fully establish the potential benefit of early EN, preferably compared with minimal enteral nutrition
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