Long-Term Dagum-PVF Frailty Regression Model: Application in Health Studies

Survival models incorporating cure fractions, commonly known as cure fraction models or long-term survival models, are widely employed in epidemiological studies to account for both immune and susceptible patients in relation to the failure event of interest under investigation. In such studies, there is also a need to estimate the unobservable heterogeneity caused by prognostic factors that cannot be observed. Moreover, the hazard function may exhibit a non-monotonic form, specifically, an unimodal hazard function. In this article, we propose a long-term survival model based on the defective version of the Dagum distribution, with a power variance function (PVF) frailty term introduced in the hazard function to control for unobservable heterogeneity in patient populations, which is useful for accommodating survival data in the presence of a cure fraction and with a non-monotone hazard function. The distribution is conveniently reparameterized in terms of the cure fraction, and then associated with the covariates via a logit link function, enabling direct interpretation of the covariate effects on the cure fraction, which is not usual in the defective approach. It is also proven a result that generates defective models induced by PVF frailty distribution. We discuss maximum likelihood estimation for model parameters and evaluate its performance through Monte Carlo simulation studies. Finally, the practicality and benefits of our model are demonstrated through two health-related datasets, focusing on severe cases of COVID-19 in pregnant and postpartum women and on patients with malignant skin neoplasms

A arqueologia da África Central através dos periódicos científicos

We propose to analyze the specificities of Central Africa archaeology through an editorials and articles selection with reference to the production and dissem ination of archaeological knowledge about this region. The approach of African archaeology journals as sources to the Central Africa archaeological history results from the current discussions on the political and social role of archaeologists in building the continent’s past after the process of independence in the 20th centuryPropomos analisar as especificidades da arqueologia da África central através de um a seleção de editoriais e artigos que tratem da produção e disseminação do conhecimento arqueológico sobre essa região. A abordagem dos periódicos de arqueologia africana, enquanto fontes documentais da história da arqueologia centro-africana, decorre das discussões atuais sobre a atuação política e social dos arqueólogos na construção do passado do continente após os processos de independência do século X

Dossiê Gênero e Antiguidade: problemas e métodos

Apresentação do Dossiê Gênero e Antiguidade: problemas e método

Influence of the prone position on a stretcher for pregnant women on maternal and fetal hemodynamic parameters and comfort in pregnancy

OBJECTIVES: To analyze the influence of lying in prone position on a specially designed stretcher on the maternal-fetal hemodynamic parameters and comfort of pregnant women. METHODS: A randomized, controlled trial with 33 pregnant women divided into 2 groups: pregnant group sequence 1 and pregnant group sequence 2. The order of positions used in sequence 1 was Fowler’s position, prone position, supine position, left lateral, Fowler’s position 2, supine position 2, prone position 2 and left lateral 2. The order of positions used in sequence 2 was Fowler’s position, prone position, left lateral, supine position, Fowler’s position 2, left lateral 2, prone position 2 and supine position 2. Each woman remained in each position for 6 minutes. For the statistical analyses, we used Wilcoxon’s test for 2 paired samples when comparing the prone position with the other positions. The variables are presented in graphs showing the means and 95% confidence intervals. Trial Registration: Clinical Trial No. ISRCTN41359519 RESULTS: All the parameters were within the standards of normality. There were no differences between positions in terms of maternal heart rate, diastolic blood pressure, oxygen saturation and fetal heart rate. However, there were significant decreases in respiratory rate and systolic blood pressure in prone position 2 compared with left lateral 2. There was an increase in oxygen saturation in prone position compared with Fowler’s position and supine position 2 in both sequences. All the women reported feeling comfortable in the prone position. CONCLUSIONS: The prone position was considered safe and comfortable and could be advantageous for improving oxygen saturation and reducing the systolic blood pressure and respiratory rate

RELATO DE UMA OFICINA TEÓRICO-PRÁTICA: REPRESENTAÇÃO EM PERSPECTIVA

A perspectiva é uma técnica utilizada para representar as formas e a profundidade espacial sobre uma superfície plana, e que se desenvolve por meio da percepção visual do indivíduo. É uma representação visual que possibilita conexões entre Matemática e Artes Visuais. Neste relato de experiência, descrevemos a Oficina denominada ‘Representação em perspectiva: uma proposta interdisciplinar para o ensino de Geometria’, que teve por objetivo propiciar conhecimentos interdisciplinares sobre a técnica da representação em perspectiva. Para tanto, inicialmente apresentamos a Oficina, seus objetivos, sua importância e os procedimentos metodológicos adotados. Em seguida, realizamos um breve panorama da Perspectiva no Renascimento e na atualidade, descrevendo todo o processo de realização da Oficina. Apresentamos também dados parciais da Oficina, como produções realizadas pelos sete participantes e alguns resultados obtidos por meio das falas dos sujeitos. Para a apresentação dos dados descritivos da Oficina, realizou-se uma análise de conteúdo, em que optou-se por evidenciar somente aqueles sujeitos e suas respectivas falas que indicavam as contribuições da Oficina e a relevância da temática abordada. Finalmente, são apresentadas algumas reflexões sobre a temática e a realização da Oficina