Network influence effects in agent-based modelling of civil violence

In this paper we describe an agent-based model of civil violence with network influence effects. We considered two different networks, ‘family’ and ‘news’, as a simplified representation of multiple-context influences, to study their individual and joint impact on the size and timing of violence bursts, the perceived legitimacy, and the system’s long term behaviour. It was found that network influences do not change either the system’s long term behaviour or the periodicity of the rebellion peaks, but increase the size of violence bursts, particularly for the case of strong ‘news impact’. For certain combinations of network influences, initial legitimacy, and legitimacy feedback formulation, the solutions showed a very complicated behaviour with unpredictable alternations between long periods of calm and turmoil.info:eu-repo/semantics/acceptedVersio

Habilidades cognitivas e projectos de vida: Estudo na transição do 1º para o 2º ciclo de escolaridade

Resumo: Neste estudo os autores, tomando um grupo de alunos do 5º e 6º anos de escolaridade (n=1166) provenientes de comunidades urbanas e rurais, analisam as correlações entre as habilidades cognitivas avaliadas através de uma bateria de quatro provas de raciocínio (Bateria de Provas de Raciocínio, BPR5/6) e informação relativa ao percurso escolar e aos projectos futuros de escolarização por parte dos alunos. Ao nível do percurso escolar considera-se o número de reprovações anteriores, assim como as classificações actuais em várias disciplinas. Em termos dos projectos futuros, considera-se a extensão da escolarização que o aluno pretende realizar (estudar até quando?) e a sua opção por uma formação mais académica ou mais profissionalizante. Foi encontrada uma correlação estatisticamente significativa entre as medidas da habilidade cognitiva e o rendimento académico, em ambos os anos de escolaridade, situando-se o coeficiente de correlação acima de .60 quando tomamos uma medida global do rendimento escolar e do desempenho na bateria de raciocínio. Além disso, a análise da variância dos resultados nas provas psicológicas sugere-nos que o actual desempenho cognitivo dos alunos está associado ao seu anterior percurso escolar, nomeadamente ao número de retenções em anos anteriores. Tomando os indicadores da projecção dos alunos em termos de futuro escolar e profissional, verifica-se que as habilidades cognitivas actuais e os resultados escolares anteriores explicam 25% da variabilidade individual encontrada nos projectos vocacionais em termos de prolongamento da escolaridade e da maior propensão por uma formação académica ou mais profissionalizante

Ethyl 7-Acetyl-8a-methyl-3-(1-phenyl-1H-tetrazol-5-yl)-1,4,4a,5,6,8a-hexahydro-7H-pyrano[2,3-c]pyridazine-1-carboxylate

The Diels–Alder reaction of ethyl 3-(1-phenyl-1H-tetrazol-5-yl-1,2-diaza-1,3-butadiene-1-carboxylate with 2-acetyl-6-methyl-2,3-dihydro-4H-pyran (methyl vinyl ketone dimer) regioselectively afforded the corresponding 3-(tetrazol-5-yl)-hexahydro-7H-pyrano[2,3-c]pyridazine in quantitative yield. An X-ray crystal structure of this cycloadduct is reported.info:eu-repo/semantics/publishedVersio

Characterization of new exopolysaccharide production by Rhizobium tropici during growth on hidrocarbon substrate.

Made available in DSpace on 2017-11-08T23:29:06Z (GMT). No. of bitstreams: 1 PCharacterizationofnewexopolysaccharide....pdf: 1212598 bytes, checksum: 41efcdb7f61e0fa725e08b591933202d (MD5) Previous issue date: 2017-11-08bitstream/item/166445/1/P-Characterization-of-new-exopolysaccharide....pd

Lista preliminar de borboletas (Insecta: Lepidoptera) dos municípios de Amapá e Tartarugalzinho, AP.

Resumo 10

A toggle-switch and a feed-forward loop engage in the control of the Drosophila retinal determination gene network

Dipterans show a striking range of eye sizes, shapes, and functional specializations. Their eye is of the compound type, the most frequent eye architecture in nature. The development of this compound eye has been most studied in Drosophila melanogaster. The early development of the Drosophila eye is under the control of a gene regulatory network of transcription factors and signaling molecules called the retinal determination gene network (RDGN). Nodes in this network have been found to be involved not only in the development of different eye types in invertebrates and vertebrates, but also of other organs. Here we have analyzed the network properties in detail. First, we have generated quantitative expression profiles for a number of the key RDGN transcription factors, at a single-cell resolution. With these profiles, and applying a correlation analysis, we revisited several of the links in the RDGN. Our study uncovers a new link, that we confirm experimentally, between the transcription factors Hth/Meis1 and Optix/Six3 and indicates that, at least during the period of eye differentiation, positive feedback regulation from Eya and Dac on the Pax6 gene Ey is not operating. From this revised RDGN we derive a simplified gene network that we model mathematically. This network integrates three basic motifs: a coherent feedforward loop, a toggle-switch and a positive autoregulation which, together with the input from the Dpp/BMP2 signaling molecule, recapitulate the gene expression profiles obtained experimentally, while ensuring a robust transition from progenitor cells into retinal precursors.This work was funded by MINECO and the Agencia Estatal de Investigacion (AEI) of Spain, co-financed by FEDER funds (EU) through grants BFU2012-34324 and BFU2015-66040-P to FC, MDM-2016-0687 in which FC is participant researcher, and TIN2017-89842 P in which MCL is participant researcher