Estudo das isotermas de dessorção de sementes de cornichão (Lotus corniculátus L.).

SIEPE

Estudo da cinética de secagem de sementes de cornichão (Lotus corniculátus L.) em leito fixo com escoamento de ar paralelo.

SIEPE

Avaliação da tolerância de acesso do gênero Paspalum ao sombreamento.

Editado por Ana Rita de Araújo Nogueira, Simone Cristina Meo Niciura

Eddington accreting black holes in the epoch of reionization

The evolution of the luminosity function (LF) of active galactic nuclei (AGNs) at redshift z ≳ 5 represents a key constraint to understand their contribution to the ionizing photon budget necessary to trigger the last phase transition in the Universe, i.e. the epoch of reionization. Recent searches for bright high-z AGNs suggest that the space densities of this population at z > 4 have to be revised upwards, and spark new questions about their evolutionary paths. Gas accretion is the key physical mechanism to understand both the distribution of luminous sources and the growth of central supermassive black holes (SMBHs). In this work, we model the high-z AGN-LF assuming that high-z luminous AGNs shine at their Eddington limit: We derive the expected evolution as a function of the ‘duty cycle’ (fdc), i.e. the fraction of lifetime that a given SMBH spends accreting at the Eddington rate. Our results show that intermediate values (fdc ≃ 0.1) predict the best agreement with the ionizing background and photoionization rate, but do not provide enough ionizing photons to account for the observed evolution of the hydrogen neutral fraction. Smaller values (fdc≲ 0.05) are required for AGNs to be the dominant population responsible for hydrogen reionization in the early Universe. We then show that this low-fdc evolution can be reconciled with the current constraints on helium reionization, although it implies a relatively large number of inactive SMBHs at z ≳ 5, in tension with SMBH growth models based on heavy seeding

Clinical and virological findings in the ongoing outbreak of West Nile virus Livenza strain in northern Italy, July to September 2012.

Binary file ES_Abstracts_Final_ECDC.txt matche

Construção e validação de um instrumento para avaliação do conhecimento dos enfermeiros sobre os medicamentos utilizados no infarto agudo do miocárdio

Introduction: The construction and validation of an instrument to evaluate nurses' knowledge about medication administration in patients with acute myocardial infarction can contribute to a safe and quality nursing care. Objective: To construct and validate a questionnaire to evaluate the knowledge of nurses about medications used for the treatment of ST-segment elevation myocardial infarction (STEMI). Methods: A methodological study that involved the construction and validation of the content of a questionnaire, as well as a semantic and idiomatic review. The degree of agreement among judges was assessed by the Content Validity Index (IVC ≥ 0.8). Results: The validated questionnaire consists of 20 questions divided into 4 sessions: I- Expected action of the medication, II- Adverse effects, III- Nursing care, IV- Route of administration and V- Contraindications. In the evaluation of the judges 19 questions obtained IVC≥0.8; 7 questions were corrected and 1 question was reworked as suggested by the judges. Conclusion: The questionnaire constructed in this study provides a validated and reliable data collection instrument for the evaluation of nurses' knowledge on the topic of medications used to treat STEMI.Introdução: A construção e validação de instrumento para avaliar o conhecimento dos enfermeiros quanto ao tema administração de medicamentos em pacientes acometidos por infarto agudo do miocárdio pode contribuir para a busca de uma assistência de enfermagem segura e de qualidade. Objetivo: Construir e validar um questionário para avaliar o conhecimento de enfermeiros sobre os medicamentos utilizados no tratamento de infarto agudo do miocárdio com supradesnível do segmento ST (IAM CSST). Métodos: Estudo metodológico de construção e validação de conteúdo de um questionário, além de revisão semântica e idiomática. O grau de concordância entre juízes foi avaliado pelo Índice de Validade de Conteúdo e considerado ponto de corte (IVC ≥ 0,8). Resultados: O questionário validado está composto de 20 questões, divididas a cada 4 nas sessões: I- Ação esperada do medicamento, II-Efeitos adversos, III-Cuidados de enfermagem, IV- Via de administração e V-Contraindicações. Na avaliação dos juízes, 19 questões obtiveram IVC ≥ 0,8; 7 questões passaram por correções e 1 questão foi reelaborada conforme sugestões. Conclusão: O questionário construído neste estudo fornece um instrumento metodológico de coleta de dados validado e confiável para avaliação do conhecimento de enfermeiros sobre os medicamentos utilizados para tratamento de IAM CSST

Driving calmodulin protein towards conformational shift by changing ionization states of select residues

Proteins are complex systems made up of many conformational sub-states which are mainly determined by the folded structure. External factors such as solvent type, temperature, pH and ionic strength play a very important role in the conformations sampled by proteins. Here we study the conformational multiplicity of calmodulin (CaM) which is a protein that plays an important role in calcium signaling pathways in the eukaryotic cells. CaM can bind to a variety of other proteins or small organic compounds, and mediates different physiological processes by activating various enzymes. Binding of calcium ions and proteins or small organic molecules to CaM induces large conformational changes that are distinct to each interacting partner. In particular, we discuss the effect of pH variation on the conformations of CaM. By using the pKa values of the charged residues as a basis to assign protonation states, the conformational changes induced in CaM by reducing the pH are studied by molecular dynamics simulations. Our current view suggests that at high pH, barrier crossing to the compact form is prevented by repulsive electrostatic interactions between the two lobes. At reduced pH, not only is barrier crossing facilitated by protonation of residues, but also conformations which are on average more compact are attained. The latter are in accordance with the fluorescence resonance energy transfer experiment results of other workers. The key events leading to the conformational change from the open to the compact conformation are (i) formation of a salt bridge between the N-lobe and the linker, stabilizing their relative motions, (ii) bending of the C-lobe towards the N-lobe, leading to a lowering of the interaction energy between the two-lobes, (iii) formation of a hydrophobic patch between the two lobes, further stabilizing the bent conformation by reducing the entropic cost of the compact form, (iv) sharing of a Ca+2 ion between the two lobes

Seasonality of soil water exchange in the soybean growing season in southern Brazil

The processes of water transfer in the soil-plant-atmosphere system are strongly affected by soil use and management. Differences in the dynamics of soil water transfer between no-tillage (NT) and conventional tillage (CT) practices during a soybean (Glycine max) growing season in southern Brazil were assessed in this study. All the water balance components were analyzed during the soybean growing season (2009/2010). Rainfall, runoff, soil water storage and hydro-physical soil properties were analyzed under two tillage systems. The land-atmosphere water vapor exchanges, obtained from eddy covariance stations, were analyzed with regard to the soybean agroecosystem. Characterizations of soil water storage were also formulated in the 2006/2007 and 2008/2009 soybean growing seasons under the NT system. During the periods without rain, the soil water content under NT was greater than under CT. The soil superficial layer, more porous under NT, contributed to less runoff during rainy events. Moreover, under NT conditions the water supply was always high, between 0.2 - 0.5 m. The total evapotranspiration in the soybean agroecosystem growing season was 410.8 mm

Diversidade genética e endogamia em seis populações de grevílea introduzidas no Brasil.

Resumo

Respostas produtivas de acessos de Paspalum spp. ao sombreamento artificial.

O objetivo desse trabalho foi avaliar os efeitos do sombreamento em parâmetros de crescimento e produção de catorze acessos de Paspalum spp.. Os acessos foram conduzidos em vasos irrigados e adubados sob quatro níveis de sombreamento artificial (0%, 45%, 59% e 76%), utilizando-se telas de polipropileno, durante três ciclos de crescimento, em São Carlos, SP, Brasil. Foram avaliados o número de perfilhos por vaso, altura do perfilho médio de cada planta, área foliar, área foliar específica e biomassa da parte aérea. Foi realizada uma análise de componentes principais para a associação dos regimes de sombreamento e das características morfológicas e produtivas dos acessos. Os dados de biomassa da parte aérea foram comparados pelo teste de Tukey a 5% de probabilidade. Os resultados obtidos mostraram que o sombreamento proporcionou alterações nas características morfológicas (perfilhamento, altura e área foliar) e na biomassa da parte aérea dos acessos avaliados. Dos catorze acessos estudados, sete apresentaram regressão quadrática significativa entre o nível de sombreamento e a biomassa da parte aérea. Para programas de melhoramento, quando se objetiva produzir materiais mais adaptados ao ambiente sombreado, se destacam Paspalum malacophyllum BGP-293, P. urvillei x P. dilatatum BGP-238, P. regnellii BGP-258 e P. dilatatum BGP-234 e que devem ser avaliados sob sombreamento natural para confirmar seu potencial de utilização em sistemas silvipastoris