The Likelihood Ratio Test and Full Bayesian Significance Test under small sample sizes for contingency tables

Hypothesis testing in contingency tables is usually based on asymptotic results, thereby restricting its proper use to large samples. To study these tests in small samples, we consider the likelihood ratio test and define an accurate index, the P-value, for the celebrated hypotheses of homogeneity, independence, and Hardy-Weinberg equilibrium. The aim is to understand the use of the asymptotic results of the frequentist Likelihood Ratio Test and the Bayesian FBST -- Full Bayesian Significance Test -- under small-sample scenarios. The proposed exact P-value is used as a benchmark to understand the other indices. We perform analysis in different scenarios, considering different sample sizes and different table dimensions. The exact Fisher test for $2 \times 2$ tables that drastically reduces the sample space is also discussed. The main message of this paper is that all indices have very similar behavior, so the tests based on asymptotic results are very good to be used in any circumstance, even with small sample sizes

Differential Features of Culprit Intracranial Atherosclerotic Lesions: A Whole-Brain Vessel Wall Imaging Study in Patients With Acute Ischemic Stroke.

BackgroundIntracranial atherosclerotic disease tends to affect multiple arterial segments. Using whole-brain vessel wall imaging, we sought to study the differences in plaque features among various types of plaques in patients with a recent unilateral anterior circulation ischemic stroke.Methods and resultsSixty-one patients with unilateral anterior circulation ischemic stroke were referred to undergo whole-brain vessel wall imaging (before and after contrast) within 1 month of symptom onset for intracranial atherosclerotic disease evaluations. Each plaque was classified as a culprit, probably culprit, or nonculprit lesion, according to its likelihood of causing the stroke. The associations between plaque features (thickening pattern, plaque-wall contrast ratio, high signal on T1-weighted images, plaque contrast enhancement ratio, enhancement grade, and enhancement pattern) and culprit lesions were estimated using mixed multivariable logistic regression after adjustment for maximum wall thickness. In 52 patients without motion corruption in whole-brain vessel wall imaging, a total of 178 intracranial plaques in the anterior circulation were identified, including 52 culprit lesions (29.2%), 51 probably culprit lesions (28.7%), and 75 nonculprit lesions (42.1%). High signal on T1-weighted images (adjusted odds ratio, 9.1; 95% confidence interval, 1.9-44.1; P=0.006), grade 2 (enhancement ratio of plaque ≥ enhancement ratio of pituitary) contrast enhancement (adjusted odds ratio, 17.4; 95% confidence interval, 1.8-164.9; P=0.013), and type 2 (≥50% cross-sectional wall involvement) enhancement pattern (adjusted odds ratio, 10.1; 95% confidence interval, 1.3-82.2; P=0.030) were independently associated with culprit lesions.ConclusionsHigh signal on T1-weighted images, grade 2 contrast enhancement, and type 2 enhancement pattern are associated with cerebrovascular ischemic events, which may provide valuable insights into risk stratification

Adherence to BCLC recommendations for the treatment of hepatocellular carcinoma: impact on survival according to stage

OBJECTIVES: This study sought to assess the adherence of newly diagnosed hepatocellular carcinoma patients to the Barcelona Clinic Liver Cancer system treatment guidelines and to examine the impact of adherence on the survival of patients in different stages of the disease. METHODS: This study included all patients referred for the treatment of hepatocellular carcinoma between 2010 and 2012. Patients (n=364) were classified according to the Barcelona Clinic Liver Cancer guidelines. Deviations from the recommended guidelines were discussed, and treatment was determined by a multidisciplinary team. The overall survival curves were estimated with the Kaplan-Meier method and were compared using the log-rank test. RESULTS: The overall rate of adherence to the guidelines was 52%. The rate of adherence of patients in each scoring group varied as follows: stage 0, 33%; stage A, 45%; stage B, 78%; stage C, 35%; and stage D, 67%. In stage 0/A, adherent patients had a significantly better overall survival than non-adherent patients (hazard ratio=0.19, 95% confidence interval (CI): 0.09-0.42;

An analysis of tacrolimus-related complications in the first 30 days after liver transplantation

OBJECTIVES: Orthotopic liver transplantation has improved survival in patients with end-stage liver disease; however, therapeutic strategies that achieve ideal immunosuppression and avoid early complications are lacking. To correlate the dose and level of Tacrolimus with early complications, e.g., rejection, infection and renal impairment, after liver transplantation. From November 2011 to May 2013, 44 adult liver transplant recipients were studied in this retrospective comparative study. RESULTS: The most frequent indication for liver transplantation was hepatitis C cirrhosis (47.7%), with a higher prevalence observed in male patients (68.18%). The ages of the subjects ranged from 19-71 and the median age was 55.5 years. The mean length of the hospital stay was 16.1±9.32 days and the mean Model for End-stage Liver Disease score was 26.18±4.28. There were five cases of acute cellular rejection (11.37%) and 16 cases of infection (36.37%). The blood samples that were collected and analyzed over time showed a significant correlation between the Tacrolimus blood level and the deterioration of glomerular filtration rate and serum creatinine (

Ferramentas e Aspectos Práticos da TV Digital Técnica Projectos / Tools and Practical Aspects of Digital TV Technical Projects

A TV aberta é um importante ator de comunicação na sociedade contemporânea com alguns padrões de sucesso, entre eles o Sistema Brasileiro de Televisão Digital Terrestre (SBTVD-T). Este artigo discute aspectos relacionados à construção de um projeto técnico para obtenção de outorgas para o serviço de televisão e seus serviços ancilares no Brasil. Apresentamos algumas ferramentas de livre acesso que podem ser utilizadas para realizar tal atividade. Por fim, um estudo de caso apresenta a construção do projeto técnico da TV Universitária, uma emissora de TV da Universidade Federal do Rio Grande do Norte, Brasil. Como principal resultado, pretendeu-se preencher a lacuna de material técnico relacionado ao uso de ferramentas abertas e bases de dados governamentais para a construção de projetos técnicos de TV digital no Brasil

Aspectos da Legislação e Procedimentos para a Concessão da TV Digital e dos seus Serviços Auxiliares no Brasil / Legislation and Procedures Aspects for the Grant of Digital TV and Its Ancillary Services in Brazil

O serviço de radiodifusão sonora e de imagens continua sendo um dos principais veículos de mídia e informação da sociedade contemporânea e vem passando por um longo processo de alteração de seus aspectos regulatórios decorrente da implantação do Sistema Brasileiro de Televisão Digital Terrestre (SBTVD-T). Este artigo apresenta e discute os procedimentos para obtenção de outorgas para o serviço de televisão e seus serviços ancilares no Brasil. Como resultado principal, pretendeu-se preencher a lacuna por material técnico relacionado à discussão da legislação da TV digital no Brasil

Early and Late Pathogenic Events of Newborn Mice Encephalitis Experimentally Induced by Itacaiunas and Curionópolis Bracorhabdoviruses Infection

In previous reports we proposed a new genus for Rhabdoviridae and described neurotropic preference and gross neuropathology in newborn albino Swiss mice after Curionopolis and Itacaiunas infections. In the present report a time-course study of experimental encephalitis induced by Itacaiunas and Curionopolis virus was conducted both in vivo and in vitro to investigate cellular targets and the sequence of neuroinvasion. We also investigate, after intranasal inoculation, clinical signs, histopathology and apoptosis in correlation with viral immunolabeling at different time points. Curionopolis and Itacaiunas viral antigens were first detected in the parenchyma of olfactory pathways at 2 and 3 days post-inoculation (dpi) and the first clinical signs were observed at 4 and 8 dpi, respectively. After Curionopolis infection, the mortality rate was 100% between 5 and 6 dpi, and 35% between 8 and 15 dpi after Itacaiunas infection. We identified CNS mice cell types both in vivo and in vitro and the temporal sequence of neuroanatomical olfactory areas infected by Itacaiunas and Curionopolis virus. Distinct virulences were reflected in the neuropathological changes including TUNEL immunolabeling and cytopathic effects, more intense and precocious after intracerebral or in vitro inoculations of Curionopolis than after Itacaiunas virus. In vitro studies revealed neuronal but not astrocyte or microglial cytopathic effects at 2 dpi, with monolayer destruction occurring at 5 and 7 dpi with Curionopolis and Itacaiunas virus, respectively. Ultrastructural changes included virus budding associated with interstitial and perivascular edema, endothelial hypertrophy, a reduced and/or collapsed small vessel luminal area, thickening of the capillary basement membrane, and presence of phagocytosed apoptotic bodies. Glial cells with viral budding similar to oligodendrocytes were infected with Itacaiunas virus but not with Curionopolis virus. Thus, Curionopolis and Itacaiunas viruses share many pathological and clinical features present in other rhabdoviruses but distinct virulence and glial targets in newborn albino Swiss mice brain