Um modelo baseado no indivíduo para estudo da transmissão da anemia infecciosa equina por mutuca no Pantanal brasileiro.

Resumo. A Anemia Infeciosa Equina (AIE) é uma doença causada por um retrovírus e transmitida pelo inseto hematófago conhecido como mutuca (tabanídeo), sendo observada nas últimas décadas a prevalência de 50% entre os animais de serviço no Pantanal brasileiro. Este trabalho apresenta um modelo baseado no indivíduo para analisar a dinâmica de transmissão da AIE pela mutuca no Pantanal. Considerando um período de 40 anos de simulação, os resultados mostram que a mutuca não pode ser responsável sozinha pela alta prevalência da doença na região, sendo necessário estudos mais detalhados das práticas de manejo usadas.SBIAgro 2013

Uso da modelagem baseada no indivíduo para estudo da dinâmica de propagação de doença no cavalo pantaneiro.

Este trabalho objetiva o uso da modelagem baseada no indivíduo (MBI) para analisar a dinâmica de propagação da anemia infecciosa equina (AIE) em cavalos de serviço usando o software TerraME, desenvolvido pelo INPE.CIIC 2013. No 13605

Creating pseudo Kondo-resonances by field-induced diffusion of atomic hydrogen

In low temperature scanning tunneling microscopy (STM) experiments a cerium adatom on Ag(100) possesses two discrete states with significantly different apparent heights. These atomic switches also exhibit a Kondo-like feature in spectroscopy experiments. By extensive theoretical simulations we find that this behavior is due to diffusion of hydrogen from the surface onto the Ce adatom in the presence of the STM tip field. The cerium adatom possesses vibrational modes of very low energy (3-4meV) and very high efficiency (> 20%), which are due to the large changes of Ce-states in the presence of hydrogen. The atomic vibrations lead to a Kondo-like feature at very low bias voltages. We predict that the same low-frequency/high-efficiency modes can also be observed at lanthanum adatoms.Comment: five pages and four figure

Long-range Kondo signature of a single magnetic impurity

The Kondo effect, one of the oldest correlation phenomena known in condensed matter physics, has regained attention due to scanning tunneling spectroscopy (STS) experiments performed on single magnetic impurities. Despite the sub-nanometer resolution capability of local probe techniques one of the fundamental aspects of Kondo physics, its spatial extension, is still subject to discussion. Up to now all STS studies on single adsorbed atoms have shown that observable Kondo features rapidly vanish with increasing distance from the impurity. Here we report on a hitherto unobserved long range Kondo signature for single magnetic atoms of Fe and Co buried under a Cu(100) surface. We present a theoretical interpretation of the measured signatures using a combined approach of band structure and many-body numerical renormalization group (NRG) calculations. These are in excellent agreement with the rich spatially and spectroscopically resolved experimental data.Comment: 7 pages, 3 figures + 8 pages supplementary material; Nature Physics (Jan 2011 - advanced online publication

The significance of sample mass in the analysis of steroid estrogens in sewage sludges and the derivation of partition coefficients in wastewaters

Optimization of an analytical method for determination of steroid estrogens, through minimizing sample size, resulted in recoveries >84%, with relative standard deviations <3% and demonstrated the significance of sample size on method performance. Limits of detection were 2.1–5.3 ng/g. Primary sludges had estrogen concentrations of up to one order of magnitude less than those found in biological sludges (up to 994 ng/g). However, partition coefficients were higher in primary sludges (except estriol), with the most hydrophobic compound (ethinylestradiol) exhibiting the highest Kp value, information which may be of value to those involved in modeling removal during wastewater treatment

Fundamentos para a estruturação, desenvolvimento e gestão de redes de pesquisa: o caso da Rede AgroHidro da Embrapa.

A Empresa Brasileira de Pesquisa Agropecuária (Embrapa), uma instituição pública ligada ao Ministério da Agricultura, Pecuária e Abastecimento (Mapa), do governo federal brasileiro, instituiu a Rede AgroHidro para estudar as interações da agricultura com os recursos hídricos de bacias hidrográficas em diferentes biomas brasileiros. Para isto realizou-se uma pesquisa quanti-qualitativa de caráter longitudinal. Na primeira fase levantaram-se informações junto aos integrantes da Rede, sobre os aspectos relativos às competências individuais e à estrutura e gestão da Rede. Na segunda identificaram-se os elementos favorecedores da estruturação, desenvolvimento e gestão da Rede. Concluiu-se que os aspectos organizacionais e as relações e influências destes nas interações sociais ocorridas na Rede devem favorecer ações de troca de dados, informações, conhecimentos e experiências para facilitar a execução das atividades de Pesquisa, Desenvolvimento e Inovação (PD&I); promover uma gestão compartilhada para desenvolver vínculos entre os pares; estimular a organização de informações nas diversas áreas de conhecimentos e temas que envolvam as necessidades da Rede; e fortalecer as relações entre os pares a partir do estabelecimento de princípios comunicacionais voltados para autonomia crítica, dialogismo, corresponsabilidade entre os pares e pensamento complexo. Quanto aos aspectos relacionados à gestão, desenvolvimento e estruturação da Rede AgroHidro concluiu-se que as competências humanas e organizacionais existentes na Rede; o modelo de gestão praticado pelos diversos gestores que a integram; o excesso de burocracia; e o estabelecimento de papéis/atribuições claras entre os seus integrantes são fatores que favorecem, em maior ou menor grau, a estruturação, desenvolvimento e gestão da Rede.ADM 2017

Kondo Conductance in an Atomic Nanocontact from First Principles

The electrical conductance of atomic metal contacts represents a powerful tool to detect nanomagnetism. Conductance reflects magnetism through anomalies at zero bias -- generally with Fano lineshapes -- due to the Kondo screening of the magnetic impurity bridging the contact. A full atomic-level understanding of this nutshell many-body system is of the greatest importance, especially in view of our increasing need to control nanocurrents by means of magnetism. Disappointingly, zero bias conductance anomalies are not presently calculable from atomistic scratch. In this Letter we demonstrate a working route connecting approximately but quantitatively density functional theory (DFT) and numerical renormalization group (NRG) approaches and leading to a first-principles conductance calculation for a nanocontact, exemplified by a Ni impurity in a Au nanowire. A Fano-like conductance lineshape is obtained microscopically, and shown to be controlled by the impurity s-level position. We also find a relationship between conductance anomaly and geometry, and uncover the possibility of opposite antiferromagnetic and ferromagnetic Kondo screening -- the latter exhibiting a totally different and unexplored zero bias anomaly. The present matching method between DFT and NRG should permit the quantitative understanding and exploration of this larger variety of Kondo phenomena at more general magnetic nanocontacts.Comment: 11 pages, 3 figures. Supplementary materials under request at [email protected]

Influence of operating parameters on the biodegradation of steroid estrogens and nonylphenolic compounds during biological wastewater treatment processes

This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in Environmental Science & Technology, copyright © American Chemical Society after peer review. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/es901612v.This study investigated operational factors influencing the removal of steroid estrogens and nonylphenolic compounds in two sewage treatment works, one a nitrifying/denitrifying activated sludge plant and the other a nitrifying/denitrifying activated sludge plant with phosphorus removal. Removal efficiencies of >90% for steroid estrogens and for longer chain nonylphenol ethoxylates (NP4−12EO) were observed at both works, which had equal sludge ages of 13 days. However, the biological activity in terms of milligrams of estrogen removed per day per tonne of biomass was found to be 50−60% more efficient in the nitrifying/denitrifying activated sludge works compared to the works which additionally incorporated phosphorus removal. A temperature reduction of 6 °C had no impact on the removal of free estrogens, but removal of the conjugated estrone-3-sulfate was reduced by 20%. The apparent biomass sorption (LogKp) values were greater in the nitrifying/denitrifying works than those in the nitrifying/denitrifying works with phosphorus removal for both steroid estrogens and nonylphenolic compounds possibly indicating a different cell surface structure and therefore microbial population. The difference in biological activity (mg tonne−1 d−1) identified in this study, of up to seven times, suggests that there is the potential for enhancing the removal of estrogens and nonylphenols if more detailed knowledge of the factors responsible for these differences can be identified and maximized, thus potentially improving the quality of receiving waters.Public Utilities Board (Singapore), Anglian Water Ltd, Severn Trent Water Ltd, Thames Water Utilities Ltd, United Utilities 393 Plc and Yorkshire Water Services

Simultaneous determination of natural and synthetic steroid estrogens and their conjugates in aqueous matrices by liquid chromatography / mass spectrometry

An analytical method for the simultaneous determination of nine free and conjugated steroid estrogens was developed with application to environmental aqueous matrices. Solid phase extraction (SPE) was employed for isolation and concentration, with detection by liquid chromatography/mass spectrometry (LC/MS) using electrospray ionisation (ESI) in the negative mode. Method recoveries for various aqueous matrices (wastewater, lake and drinking water) were determined, recoveries proving to be sample dependent. When spiked at 50 ng/l concentrations in sewage influent, recoveries ranged from 62-89 % with relative standard deviations (RSD) < 8.1 %. In comparison, drinking water spiked at the same concentrations had recoveries between 82-100 % with an RSD < 5%. Ion suppression is a known phenomenon when using ESI; hence its impact on method recovery was elucidated for raw sewage. Both ion suppression from matrix interferences and the extraction procedure has bearing on the overall method recovery. Analysis of municipal raw sewage identified several of the analytes of interest at ng/l concentrations, estriol (E3) being the most abundant. Only one conjugate, estrone 3-sulphate (E1-3S) was observe