Response of vegetation to fire disturbance: short-term dynamics in two savanna physiognomies

Fire is a constitutive ecological force in savanna ecosystems, but few studies have monitored its short-term effects on plant community dynamics. This study investigated changes in plant diversity in the South American savanna (Cerrado) after severe disturbance by fire. We monitored 30 permanent plots (10 m × 5 m) distributed in two Cerrado physiognomies (típico: more forested; ralo: grass-dominated), being 10 plots in the area disturbed by fire, and five in a preserved control area (undisturbed). From August 2010 to June 2011, we evaluated changes in species richness, abundance and composition of savanna vegetation. Monitoring started one week after the fire; disturbed plots were surveyed monthly, while control plots were surveyed every two months. We observed rapid reassembling in both physiognomies: plots affected by fire showed rapid increase in species richness and plant density during the first four months after the disturbance. Concerning species composition, disturbed plots in the cerrado típico tended to converge to control plots after one year, but each local assemblage followed particular temporal trajectories. A different pattern characterized cerrado ralo plots, which showed heterogeneous trajectories and lack of convergence between disturbed and control plots; the structure of these assemblages will likely change in next years. In conclusion, our results showed that fire significantly affected plant diversity in the two savanna physiognomies (cerrado típico and ralo), but also indicated that community reassembling is fast, with different dynamics between Cerrado physiognomies

Filmes de acetato de celulose incorporados de óleos essenciais com atividade contra microrganismos patogênicos e deterioradores de alimentos.

bitstream/item/145739/1/BPD16008.pd

FREQUÊNCIA E FATORES ASSOCIADOS À ATIVIDADE FÍSICA NO LAZER ENTRE ADULTOS NO BRASIL E NA AMAZÔNIA LEGAL: ESTUDO DE BASE POPULACIONAL / FREQUENCY AND FACTORS ASSOCIATED WITH LEISURE PHYSICAL ACTIVITY AMONG ADULTS IN BRAZIL AND IN THE AMAZON: POPULATION-BASED STUDY

Introdução: A prática regular de atividade física tem sido recomendada como importante estratégia de promoção em saúde,mas a inatividade física ainda permanece alta em várias regiões. Objetivo: Investigar a frequência e fatores associados à atividadefísica de lazer nas regiões brasileiras e nos estados que compõem a sua Amazônia legal. Métodos: Trata-se de um estudotransversal baseado num inquerido domiciliar de residentes de todas as regiões do Brasil, realizada em 2008 pelo InstitutoBrasileiro de Geografia e Estatística (IBGE). Utilizou-se uma amostra de 186.424 indivíduos com idade entre 20 e 59 anos. Avariável dependente foi atividade física de lazer. Resultados: A frequência da AFL no Brasil foi de 13,8% e entre os estados daAmazônia legal foi de 10,8%. A AFL no Brasil foi maior entre as mulheres na idade entre 20 a 29 anos e na Amazônia legal foientre os homens. Independente da região, quanto maior a renda, escolaridade e autoavaliação de saúde maior a frequência deatividade física de lazer. Conclusão: Atividade física de lazer é menos praticada por pessoas com maior vulnerabilidade socioeconômicae pelos moradores da Amazônia Legal, mesmo que eles tenham os mesmos níveis socioeconômicos dos moradoresdo Brasil.Palavras-chave: Atividade motora. Fatores Socioeconômicos. Estudos Transversais. Desigualdades em Saúde.AbstractIntroduction: Regular physical activity (RPA) has been recommended as an important health promotion strategy, but physicalinactivity remains high in several regions. Objective: To investigate the frequency and factors associated with leisure RPA inBrazilian regions and states that make up its legal Amazon. Methods: This is a cross-sectional study based on a populationbasedsurvey in residents of all regions of Brazil, conducted in 2008 by the Brazilian Institute of Geography and Statistics (IBGE,in Portuguese). We used a sample of 186,424 individuals aged between 20 and 59 years. The dependent variable was leisureRPA. Results: The frequency of leisure RPA in Brazil was 13.8% and among the states of the Amazon region was 10.8%. The leisureRPA in Brazil was higher among women aged between 20 to 29 years and in the Legal Amazon was among men. Regardlessof the region, the higher the income, schooling and health self-assessment the frequency of leisure RPA. Conclusion: Leisure RPAis less practiced by people with higher socioeconomic vulnerability and by the inhabitants of the Amazon, even if they have thesame socioeconomic status of the residents of Brazil.Keywords: Motor Activity. Cross-Sectional Studies. Socioeconomic Factors. Health Inequalitie

New Suns in the Cosmos II: differential rotation in Kepler Sun-like stars

The present study reports the discovery of Sun-like stars, namely main-sequence stars with T_eff, log g and rotation periods P_rot similar to solar values, presenting evidence of surface differential rotation (DR). An autocorrelation of the time series was used to select stars presenting photometric signal stability from a sample of 881 stars with light curves collected by the Kepler space-borne telescope, in which we have identified 17 stars with stable signals. A simple two-spot model together with a Bayesian information criterion were applied to these stars in the search for indications of DR; in addition, for all 17 stars, it was possible to compute the spot rotation period P, the mean values of the individual spot rotation periods and their respective colatitudes, and the relative amplitude of the DR

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum