Decision theory applied to image quality control in radiology

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Multidimensional Signals and Analytic Flexibility: Estimating Degrees of Freedom in Human-Speech Analyses

Recent empirical studies have highlighted the large degree of analytic flexibility in data analysis that can lead to substantially different conclusions based on the same data set. Thus, researchers have expressed their concerns that these researcher degrees of freedom might facilitate bias and can lead to claims that do not stand the test of time. Even greater flexibility is to be expected in fields in which the primary data lend themselves to a variety of possible operationalizations. The multidimensional, temporally extended nature of speech constitutes an ideal testing ground for assessing the variability in analytic approaches, which derives not only from aspects of statistical modeling but also from decisions regarding the quantification of the measured behavior. In this study, we gave the same speech-production data set to 46 teams of researchers and asked them to answer the same research question, resulting in substantial variability in reported effect sizes and their interpretation. Using Bayesian meta-analytic tools, we further found little to no evidence that the observed variability can be explained by analysts’ prior beliefs, expertise, or the perceived quality of their analyses. In light of this idiosyncratic variability, we recommend that researchers more transparently share details of their analysis, strengthen the link between theoretical construct and quantitative system, and calibrate their (un)certainty in their conclusions

Efeito do ácido ascórbico e da hidrocortisona na cicatrização anastomótica intestinal

OBJETIVO: Comparar a resistência cicatricial de anastomoses jejunais em ratos, submetidos à administração de vitamina C e de hidrocortisona, em distintos períodos pós-operatórios. MÉTODOS: Foram estudados 40 ratos Wistar, submetidos à secção e subsequente anastomose término-terminal de segmento jejunal, a 10 cm da flexura duodenojejunal. Os animais foram distribuídos em quatro grupos (n=10): Grupo I - controle; Grupo II - administração de vitamina C oral 100 mg/kg; Grupo III - administração de hidrocortisona intraperitoneal 10 mg/kg; Grupo IV - administração de vitamina C mais hidrocortisona nas doses e vias de administração acima. Avaliaram-se as pressões de ruptura anastomótica no 5º e 21º dias do pós-operatório. RESULTADOS: Os ratos que receberam vitamina C isolada ou associada a hidrocortisona tenderam a ter pressão de ruptura maior do que os demais grupos, tanto no 5º quanto no 21º dia pós-operatório. CONCLUSÃO: A vitamina C contribui para aumentar a resistência das anastomoses jejunais dos ratos durante os primeiros cinco dias do pós-operatório. A resistência das anastomoses jejunais murinas foi pouco influenciada pela administração de corticóide intraperitoneal