Optimal diffusion in ecological dynamics with Allee effect in a metapopulation

How diffusion impacts on ecological dynamics under the Allee effect and spatial constraints? That is the question we address. Employing a microscopic minimal model in a metapopulation (without imposing nonlinear birth and death rates) we evince --- both numerically and analitically --- the emergence of an optimal diffusion that maximises the survival probability. Even though, at first such result seems counter-intuitive, it has empirical support from recent experiments with engineered bacteria. Moreover, we show that this optimal diffusion disappears for loose spatial constraints.Comment: 16 pages; 6 figure

Biodiversidade e silvicultura: abundância relativa de Nothura maculosa em plantações de eucalipto e campos nativos no Sul do Brasil

Nas últimas décadas, o agronegócio tem apresentado grande expansão no bioma Pampa. A silvicultura, principalmente com eucalipto, expandiu seu plantio no estado do Rio Grande do Sul (RS), sul do Brasil. O objetivo deste estudo é contribuir para o entendimento do impacto das florestas plantadas na biodiversidade do Pampa brasileiro, através da comparação da abundância relativa de Nothura maculosa em áreas de campo nativo e áreas com plantios jovens (6–12 meses) de eucalipto. Cães de aponte foram utilizados para definir a abundância relativa (indivíduos por hora) de N. maculosa em 16 fazendas e dez plantações de eucalipto. O total de 307 indivíduos de N. maculosa foi registrado nas 26 propriedades amostradas, sendo 188 em pastagens (média de 12,6 ind.h-1) e 119 em plantios de eucalipto (média de 13,5 ind.h-1). Não foram encontradas diferenças estatisticamente significantes entre as áreas amostradas (p = 0,18; α = 0,05). A principal conclusão deste estudo é que quando o mosaico espaço-temporal de paisagem é considerado, o termo “deserto verde” fica bastante limitado.Over the last decades, agribusiness has shown a great expansion in the Pampa Biome. Forestry, mainly with eucalyptus, has expanded its planting in the Rio Grande do Sul state, southern Brazil. The objective of this study was to contribute to the understanding of the impact of planted forests on Brazilian Pampa biodiversity, through the comparison of the relative abundance of Nothura maculosa in areas of native field and areas with young (aged 6–12 months) eucalyptus. Pointing dogs were used to define the relative abundance (individuals per hour) of N. maculosa on 16 farms and ten eucalyptus plantations. A total of 307 individuals of N. maculosa were recorded on the 26 sampled properties, of which 188 were found in grasslands (average of 12.6 ind.h-1) and 119 in eucalyptus plantings (average of 13.5 ind.h-1). No statistically significant differences were found between the sampled areas (p = 0.18; α = 0.05). The main conclusion of this study is that when the landscape spatial-temporal mosaic is considered, the term “green desert” become quite limited

Comparative external morphology of the three species of the Telchin licus (Drury) complex (Lepidoptera, Castniidae) with a synonymy

É apresentado um estudo morfológico detalhado da cabeça, do tórax e do abdome de três espécies próximas de castníideos neotropicais. O posicionamento taxonômico dessas espécies é ainda bastante controverso. Antes do desenvolvimento do presente estudo, duas dessas espécies pertenciam ao gênero Telchin Hübner, 1825 e uma ao gênero monotípico Castniomera Houlbert, 1918 (espécie-tipo: Castnia atymnius Dalman, 1824). A hipótese de alguns autores de incluir as três espécies do complexo T. licus em um único gênero é aqui sustentada com base em evidências morfológicas de cabeça, tórax e abdome. Castniomera Houlbert torna-se sinônimo de Telchin Hübner compreendendo as seguintes espécies: Telchin licus (Drury, 1773), Telchin syphax (Fabricius, 1775) e Telchin atymnius (Dalman) combinação nova. As três espécies do complexo T. licus são ilustradas com desenhos e fotografias coloridas.A detailed morphological study of head, thorax, and abdomen is provided for three closely related species of Neotropical sun-moths. The taxonomic position of these species is controversial. Prior to the present study two of these species belonged to the genus Telchin Hübner, 1825, and one to the monotypic genus Castniomera Houlbert, 1918 (type species: Castnia atymnius Dalman, 1824). The hypothesis of some authors of placing the three species in a single genus is here supported on morphological evidences from head, thorax, and abdomen. Castniomera Houlbert is treated as synonym of Telchin Hübner comprising the following species: Telchin licus (Drury, 1773), Telchin syphax (Fabricius, 1775), and Telchin atymnius (Dalman) new combination. The three species of the T. licus complex are illustrated with line drawings and color photographs.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade de São Paulo (USP) - Pró-Reitoria de Pesquis

Psychoanalysis and Problem-Based Learning: Approaches and Potentials

This paper aims to analyze possible convergences between Problem Based Learning (PBL) and Psychoanalysis. It is intended to discuss how psychoanalysis can contribute to the efficiency of PBL. This by proposing reflections on affective and unconscious aspects that PBL may be neglecting. Such aspects may become more conscious and reflected, enhancing the results obtained by the PBL. Among these we can mention: teacher-student relationship; the role of tutor and its relation to the abstinence of narcissistic enjoyment; the positive connotation that can be given to the conflict arising from doubts about the problem, among others; how to deal with always partial knowledge; how to deal with the autonomy to learn and the consequent responsibility