Dung beetle diversity and functions suggest no major impacts of cattle grazing in the Brazilian Pantanal wetlands

1. Dung beetles perform relevant ecological functions in pastures, such as dung removal and parasite control. Livestock farming is the main economic activity in the Brazilian Pantanal. However, the impact of cattle grazing on the Pantanal's native dung beetle community, and functions performed by them, is still unknown. 2. This study evaluated the effects of cattle activity on dung beetle community attributes (richness, abundance, biomass, composition, and functional group) as well as their ecological functions (dung removal and soil bioturbation) in the Pantanal. In January/February 2016, dung beetles were sampled and their ecological functions measured in 16 sites of native grasslands in Aquidauana, Mato Grosso do Sul, Brazil, 10 areas regularly grazed by cattle and six control ungrazed areas (> 20 years of abandonment). 3. In all, 1169 individuals from 30 species of dung beetles were collected. Although abundance, species richness, and biomass did not differ between grasslands with and without cattle activity, species composition and functional groups differed among systems. Large roller beetles were absent from non-cattle grasslands, and the abundance, richness, and biomass of medium roller beetles was higher in those systems. 4. Despite causing changes in species/functional group composition, the results of this study show that a density compensation of functional groups in cattle-grazed natural grasslands seems to have conserved the ecological functions (dung removal and soil bioturbation), with no significant differences between systems. 5. Therefore, these results provide evidence that cattle breeding in natural grasslands of the Brazilian Pantanal can integrate livestock production with the conservation of the dung beetle community and its ecological functions. © 2019 The Royal Entomological Societ

Desenvolvimento de um programa computacional para análise técnico-tática no kendô

As artes marciais têm tido grande repercussão nos últimos anos por conta de sua esportivização, muito em função do ingresso de diversas modalidades no programa Olímpico, como judô, taekwondo e karatê. O Kendo é uma arte marcial muito tradicional, onde os praticantes e organizadores tentam mantê-lo fora dos circuitos esportivos, não dando a ele o caráter de esporte. Apesar disso, existe desenvolvimento nas competições, encontrando um caminho científico para tentar melhorar as técnicas de luta. O presente estudo teve o objetivo de desenvolver uma metodologia de análise técnica e tática no Kendo. Para este fim, um software de análise de vídeo foi desenvolvido, a fim de facilitar a coleta de dados das lutas, tendo sido nomeado VideoK. As lutas analisadas foram do 15º Campeonato Japonês de Kendo e foram disponibilizadas em um site de streaming de vídeo pela própria Federação Japonesa de Kendo. Um avaliador realizou duas coletas das quinze lutas selecionadas do campeonato para avaliar a correlação intra-avaliador. Em todas as marcações das análises foram obtidas correlações classificadas como muito boas, indicando boa reprodutibilidade. Foi possível ainda obter as médias dos alvos dos golpes das quinze lutas, sendo que a de maior ocorrência média foi o Men (cabeça), seguido por Kote (mão), Do (tronco) e Tsuki (garganta). A reprodutibilidade inter-avaliador também foi analisada, onde um segundo avaliador coletou dados de dez lutas do mesmo campeonato e os dados foram comparados com a coleta do primeiro avaliador. Todas as correlações foram classificadas como muito boas entre os dois avaliadores. Palavras-chave: kendô, esportes de combate, análise técnica, análise tática, scout

Directed Random Markets: Connectivity determines Money

Boltzmann-Gibbs distribution arises as the statistical equilibrium probability distribution of money among the agents of a closed economic system where random and undirected exchanges are allowed. When considering a model with uniform savings in the exchanges, the final distribution is close to the gamma family. In this work, we implement these exchange rules on networks and we find that these stationary probability distributions are robust and they are not affected by the topology of the underlying network. We introduce a new family of interactions: random but directed ones. In this case, it is found the topology to be determinant and the mean money per economic agent is related to the degree of the node representing the agent in the network. The relation between the mean money per economic agent and its degree is shown to be linear.Comment: 14 pages, 6 figure

The zero-inflated promotion cure rate model applied to financial data on time-to-default

In this paper, we extend the promotion cure rate model studied in Yakovlev and Tsodikov (1996) and Chen et al. (1999) by incorporating an excess of zeros in the modeling. Despite relating covariates to the cure fraction, the current approach does not enable us to relate covariates to the fraction of zeros. The presence of excess of zeros in credit risk survival data stems from a group of loans that became defaulted shortly after the granting process. Through our proposal, all survival data available of customers is modeled with a multinomial logistic link for the three classes of banking customers: (i) individual with an event at the starting time (zero time), (ii) non-susceptible for the event, or (iii) susceptible for the event. The model parameter estimation is reached by the maximum likelihood estimation procedure and Monte Carlo simulations are carried out to assess its finite sample performance

Models for optimising the theta method and their relationship to state space models

Accurate and robust forecasting methods for univariate time series are very important when the objective is to produce estimates for large numbers of time series. In this context, the Theta method’s performance in the M3-Competition caught researchers’ attention. The Theta method, as implemented in the monthly subset of the M3-Competition, decomposes the seasonally adjusted data into two “theta lines”. The first theta line removes the curvature of the data in order to estimate the long-term trend component. The second theta line doubles the local curvatures of the series so as to approximate the short-term behaviour. We provide generalisations of the Theta method. The proposed Dynamic Optimised Theta Model is a state space model that selects the best short-term theta line optimally and revises the long-term theta line dynamically. The superior performance of this model is demonstrated through an empirical application. We relate special cases of this model to state space models for simple exponential smoothing with a drift