A method for comparing non-nested models with application to astrophysical searches for new physics

Searches for unknown physics and decisions between competing astrophysical models to explain data both rely on statistical hypothesis testing. The usual approach in searches for new physical phenomena is based on the statistical Likelihood Ratio Test (LRT) and its asymptotic properties. In the common situation, when neither of the two models under comparison is a special case of the other i.e., when the hypotheses are non-nested, this test is not applicable. In astrophysics, this problem occurs when two models that reside in different parameter spaces are to be compared. An important example is the recently reported excess emission in astrophysical $\gamma$-rays and the question whether its origin is known astrophysics or dark matter. We develop and study a new, simple, generally applicable, frequentist method and validate its statistical properties using a suite of simulations studies. We exemplify it on realistic simulated data of the Fermi-LAT $\gamma$-ray satellite, where non-nested hypotheses testing appears in the search for particle dark matter.Comment: We welcome examples of non-nested models testing problem

On methods for correcting for the look-elsewhere effect in searches for new physics

The search for new significant peaks over a energy spectrum often involves a statistical multiple hypothesis testing problem. Separate tests of hypothesis are conducted at different locations producing an ensemble of local p-values, the smallest of which is reported as evidence for the new resonance. Unfortunately, controlling the false detection rate (type I error rate) of such procedures may lead to excessively stringent acceptance criteria. In the recent physics literature, two promising statistical tools have been proposed to overcome these limitations. In 2005, a method to "find needles in haystacks" was introduced by Pilla et al. [1], and a second method was later proposed by Gross and Vitells [2] in the context of the "look elsewhere effect" and trial factors. We show that, for relatively small sample sizes, the former leads to an artificial inflation of statistical power that stems from an increase in the false detection rate, whereas the two methods exhibit similar performance for large sample sizes. We apply the methods to realistic simulations of the Fermi Large Area Telescope data, in particular the search for dark matter annihilation lines. Further, we discuss the counter-intutive scenario where the look-elsewhere corrections are more conservative than much more computationally efficient corrections for multiple hypothesis testing. Finally, we provide general guidelines for navigating the tradeoffs between statistical and computational efficiency when selecting a statistical procedure for signal detection

Testing one hypothesis multiple times

In applied settings, tests of hypothesis where a nuisance parameter is only identifiable under the alternative often reduces into one of Testing One Hypothesis Multiple times (TOHM). Specifically, a fine discretization of the space of the non-identifiable parameter is specified, and the null hypothesis is tested against a set of sub-alternative hypothesis, one for each point of the discretization. The resulting sub-test statistics are then combined to obtain a global p-value. In this paper, we discuss a computationally efficient inferential tool to perform TOHM under stringent significance requirements, such as those typically required in the physical sciences, (e.g., p-value < 10−7 ). The resulting procedure leads to a generalized approach to perform inference under non-standard conditions, including non-nested models comparisons

Violence against children and adolescents: a challenge in the daily work of the nursing team

Este estudio tiene como objetivo reflexionar sobre las formas de violencia contra niños y adolescentes practicados en la familia y la importancia de la atención de enfermería ante ese fenómeno. Para esto, discute las posibilidades de ayuda y de prevención de la violencia y los problemas que esta causa en la sociedad. Se concluye que la violencia es un problema social e histórico, construido en la sociedad, y que necesita ser contemplado en la formación académica de los enfermeros.This article aims to reflect on various forms of violence against children and adolescents practiced in the family context, and the importance of professional nursing care in view of this phenomenon. We discuss possibilities of care and violence prevention as well as the problems violence causes to society. Violence is a social and historical problem, constructed in society, and needs to be adequately addressed in academic nursing education.Este artigo objetiva refletir sobre as várias formas de violência contra crianças e adolescentes, praticadas na família, e a importância da assistência dos profissionais de enfermagem diante desse fenômeno. Para isso, discutem-se as possibilidades de assistência e de prevenção da violência e os problemas que essa ocasiona à sociedade. Conclui-se que a violência é um problema social e histórico, construído na sociedade, e que precisa ser contemplado na formação acadêmica dos enfermeiros

Spatial dependence in small cooperative bank risk behavior and its effects on bank competitiveness and SMEs

AbstractIn this article we consider the effects of the inclusion of spatial dependence in the empirical model measuring small cooperative banks' risk performance. In the presence of cross‐sectional dependence, spatial analysis deals with co‐movement among geographical units, allowing for the evaluation of spillover effects and improving econometric models. The article makes several contributions to the literature. First, we support the hypothesis that the inclusion of spatial terms improves small bank soundness models. Second, with the Z Score used as a proxy for bank soundness, we indirectly test the impacts of relationship lending on small firms, which is a classic tool adopted by small banks to assess the creditworthiness of small firms. Third, since we control for banks' market power, we expand the literature on the relationship between bank risk and market competitive pressure. Finally, we find empirical evidence that bank size does affect the financial standing of small banks

Sequential hypothesis testing for Axion Haloscopes

The goal of this paper is to introduce a novel likelihood-based inferential framework for axion haloscopes which is valid under the commonly applied "rescanning" protocol. The proposed method enjoys short data acquisition times and a simple tuning of the detector configuration. Local statistical significance and power are computed analytically, avoiding the need of burdensome simulations. Adequate corrections for the look-elsewhere effect are also discussed. The performance of our inferential strategy is compared with that of a simple method which exploits the geometric probability of rescan. Finally, we exemplify the method with an application to a HAYSTAC type axion haloscope.Comment: 14 pages, 12 figure

Pandemias serão cada vez mais frequentes, e precisamos estar preparados

O médico e professor Marcelo Marcos Piva Demarzo é coordenador docente da pós-graduação lato sensu em Medicina da Família e coordenador do ambulatório de medicina geral e da família na Escola Paulista de Medicina (EPM) da Universidade Federal de São Paulo (Unifesp). É doutor em Patologia pela USP e pós-doutor em Mindfulness e Saúde Mental pela Universidad de Zaragoza, Espanha.Demarzo fala à Caminho Aberto sobre como a pandemia de Covid-19 impactou os projetos de extensão e pesquisa coordenados por ele, como o projeto de mindfullness, desenvolvido de forma presencial no Parque Ibirapuera, e que tem alcançado resultados positivos na versão on-line. O professor coordena um projeto de pesquisa pelo Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) que tem como objetivo avaliar a saúde mental dos profissionais da saúde no cenário da pandemia. Para ele, a tendência é de que pandemias sejam cada vez mais frequentes, e as universidades precisam adaptar seus projetos e ações para esse cenário. http://dx.doi.org/10.35700/ca.2020.ano7n13.p12-15.315

La suggestione nella testimonianza

La prova testimoniale è caratterizzata da una struttura complessa. Infatti, per la valutazione di una testimonianza occorre esaminare, da un lato, la narrazione di un fatto, e, da un altro lato, l’attendibilità del testimone, che può essere influenzata, in vario modo, dalle dinamiche dell’attività psichica in rapporto alla percezione ed al ricordo dei fatti, e dalle sue alterazioni a causa dell’età, del sesso, delle emozioni e passioni, del temperamento, delle illusioni e allucinazioni, delle involuzioni e malattie mentali specialmente in relazione all’attenzione e alla memoria. Al fine di evitare l’inquinamento del ricordo è fondamentale utilizzare determinate tecniche di intervista. Il presente lavoro si propone di illustrare la metodologia denominata “intervista cognitiva”, che è stata elaborata con il preciso scopo di ridurre al minimo il rischio di suggestione