Gating the charge state of a single molecule by local electric fields

The electron acceptor molecule TCNQ is found in either of two distinct integer charge states when embedded into a monolayer of a charge transfer-complex on a gold surface. Scanning tun- neling spectroscopy measurements identify these states through the presence/absence of a zero-bias Kondo resonance. Increasing the (tip-induced) electric field allows us to reversibly induce the ox- idation/reduction of TCNQ species from their anionic or neutral ground state, respectively. We show that the different ground states arise from slight variations in the underlying surface potential, pictured here as the gate of a three-terminal device.Comment: 5 pages, 4 figure

Suberin Goes Genomics: Use of a Short Living Plant to Investigate a Long Lasting Polymer

Suberin is a highly persistent cell wall polymer, predominantly composed of long-chain hydroxylated fatty acids. Apoplastic suberin depositions occur in internal and peripheral dermal tissues where they generate lipophilic barriers preventing uncontrolled flow of water, gases, and ions. In addition, suberization provides resistance to environmental stress conditions. Despite this physiological importance the knowledge about suberin formation has increased slowly for decades. Lately, the chemical characterization of suberin in Arabidopsis enabled the proposal of genes required for suberin biosynthesis such as β-ketoacyl-CoA synthases (KCS) for fatty acid elongation and cytochrome P450 oxygenases (CYP) for fatty acid hydroxylation. Advantaged by the Arabidopsis molecular genetic resources the in silico expression pattern of candidate genes, concerted with the tissue-specific distribution of suberin in Arabidopsis, led to the identification of suberin involved genes including KCS2, CYP86A1, and CYP86B1. The isolation of mutants with a modified suberin composition facilitated physiological studies revealing that the strong reduction in suberin in cyp86a1 mutants results in increased root water and solute permeabilities. The enhanced suberin 1 mutant, characterized by twofold increased root suberin content, has increased water-use efficiency and is affected in mineral ion uptake and transport. In this review the most recent findings on the biosynthesis and physiological importance of suberin in Arabidopsis are summarized and discussed

Correlation of Kondo effect and molecular conformation of the acceptor molecule in the TTF-TCNE charge transfer complex

A Kondo resonance has been observed on purely organic molecules in several combinations of charge transfer complexes on a metal surface. It has been regarded as a fingerprint of the transfer of one electron from the donor to the extended π orbital of the acceptor's LUMO. Here, we investigate the stoichiometric checkerboard structure of tetrathiafulvalene (TTF) and tetracyanoethylene (TCNE) on a Au(1 1 1) surface using scanning tunneling and atomic force microscopy at 4.8 K. We find a bistable state of the TCNE molecules with distinct structural and electronic properties. The two states represent different conformations of the TCNE within the structure. One of them exhibits a Kondo resonance, whereas the other one does not, despite of both TCNE types being singly charged

Magnetic quantum oscillations in YBa2_2Cu3_3O6.61_{6.61} and YBa2_2Cu3_3O6.69_{6.69} in fields of up to 85 T; patching the hole in the roof of the superconducting dome

We measure magnetic quantum oscillations in the underdoped cuprates YBa$_2$Cu$_3$O$_{6+x}$ with $x=0.61$, 0.69, using fields of up to 85 T. The quantum-oscillation frequencies and effective masses obtained suggest that the Fermi energy in the cuprates has a maximum at $p\approx 0.11-0.12$. On either side, the effective mass may diverge, possibly due to phase transitions associated with the T=0 limit of the metal-insulator crossover (low-$p$ side), and the postulated topological transition from small to large Fermi surface close to optimal doping (high $p$ side)

Control via electron count of the competition between magnetism and superconductivity in cobalt and nickel doped NaFeAs

Using a combination of neutron, muon and synchrotron techniques we show how the magnetic state in NaFeAs can be tuned into superconductivity by replacing Fe by either Co or Ni. Electron count is the dominant factor, since Ni-doping has double the effect of Co-doping for the same doping level. We follow the structural, magnetic and superconducting properties as a function of doping to show how the superconducting state evolves, concluding that the addition of 0.1 electrons per Fe atom is sufficient to traverse the superconducting domain, and that magnetic order coexists with superconductivity at doping levels less than 0.025 electrons per Fe atom.Comment: 4 pages, 6 figure

Entendendo e combatendo a obesidade em crianças e adolescentes

Considerando a preocupação com as consequências da alimentação contemporânea na saúde dos jovens na etapa atual e na vida futura, este artigo objetiva aumentar a compreensão e discutir aspectos associados ao sobrepeso e a obesidade nas primeiras etapas da vida. O artigo aborda a deseducação alimentar que se inicia no desmame e discute o estereótipo de que os “bebezões” são os mais saudáveis; além disso, explica como a televisão e a falta de atividade física, entre outros aspectos, podem contribuir como fatores de risco para o desenvolvimento de sobrepeso e obesidade. Por fim, este artigo fornece orientações para os pais e educadores com vistas à prevenção e tratamento do sobrepeso e da obesidade entre os jovens, com foco nos hábitos alimentares e na prática de atividade física

Integer-valued self-exciting threshold autoregressive processes

In this article, we introduce a class of self-exciting threshold integer-valued autoregressive models driven by independent Poisson-distributed random variables. Basic probabilistic and statistical properties of this class of models are discussed. Moreover, parameter estimation is also addressed. Specifically, the methods of estimation under analysis are the least squares-type and likelihood-based ones. Their performance is compared through a simulation study. Copyright © 2012 Taylor and Francis Group, LLC

Avaliação do consumo dietético, desidratação e grau de fadiga em um grupo de ciclistas amadores

Introdução e objetivo: O ciclismo é uma modalidade esportiva cada vez mais comum entre os indivíduos. Uma alimentação desiquilibrada, bem como uma ingestão hídrica inadequada podem exercer papel importante na fadiga e no desempenho do atleta. Portanto, este estudo objetivou avaliar o consumo dietético, a desidratação e o grau de fadiga de ciclistas amadores após um treino de 54 km. Materiais e métodos: Trata-se de um estudo transversal, com 12 ciclistas amadores, do sexo masculino e idade entre 27-61 anos, de um grupo de ciclistas de Santa Cruz do Sul-RS, Brasil. Determinou-se o consumo dietético pelo programa DietWin, a partir do registro alimentar de 24h. A desidratação foi determinada pela porcentagem de perda de peso e utilizou-se a escala subjetiva de Borg para avaliar o grau de fadiga. Discussão e Resultados: Dos ciclistas avaliados, 41,7% apresentavam ingestão inadequada de calorias e 50% estavam ingerindo carboidratos insuficientes, assim como 50% deles estavam consumindo gorduras em excesso. Quanto ao consumo de micronutrientes, observou-se uma prevalência de inadequação de 100% para vitamina D. Observou-se baixo consumo e ingestão acima da UL para potássio e o sódio, respectivamente. Com relação a desidratação, os ciclistas apresentaram-se levemente desidratados ou desidratação significante e o treino ciclístico realizado foi considerado razoavelmente fácil (41,7%) ou um pouco difícil (33,3%). Conclusão: Estes dados demostram que ciclistas amadores tendem a realizar uma alimentação desiquilibra, que pode influenciar no seu desempenho. Contudo, mesmo apresentando desidratação leve ou significante, pouco influenciou na percepção subjetiva de fadiga dos mesmos. ABSTRACT Evaluation of dietary intake, dehydration and degree of fatigue in a group of amateur cyclistsIntroduction and Aim: Cycling is a sport modality increasingly common among individuals. Unbalanced diet as well as inadequate water intake can play an important role in athlete fatigue and performance. Therefore, this study aimed to evaluate the dietary intake, dehydration and degree of fatigue of amateur cyclists after a training of 54 km. Materials and Methods: This is a cross-sectional study with 12 male amateur cyclists and 27-61 years old from a group of cyclists from Santa Cruz do Sul-RS, Brazil. Dietary intake was determined by the DietWin program, based on the 24-hour food record. Dehydration was determined by the percentage of weight loss and the subjective Borg scale was used to evaluate the degree of fatigue. Discussion and Results: Of cyclists evaluated, 41.7% presented inadequate calorie intake and 50% were eating insufficient carbohydrates and just as 50% of them were consuming excess fats. Regarding micronutrient intake, a prevalence of inadequacy of 100% for vitamin D was observed. Low intake and intake above UL were observed for potassium and sodium, respectively. Concerning dehydration, cyclists were slightly dehydrated or significant dehydration, and cycling training was considered reasonably easy (41.7%) or slightly difficult (33.3%). Conclusion: These data demonstrate that amateur cyclists tend to perform unbalanced feeding, which may influence their performance. However, even with mild or significant dehydration, it had little influence on the subjective perception of fatigue

ANÁLISE SÓCIOECONÔMICA DOS AGROSILVICULTORES DO PROJETO DE REFLORESTAMENTO ECONÔMICO CONSORCIADO E ADENSADO (RECA), EM NOVA CALIFÓRNIA, RONDÔNIA

O assentamento agrícola de centenas de milhares de famílias na Amazônia gerou problemas ambientais e socioeconômicos significativos na região. Em 1984 foi implantado pelo Instituto nacional de Colonização e Reforma Agrária (INCRA) o Projeto de Assentamento Agrícola do Alto Madeira, em Vila Nova Califórnia-RO, divisa com o Estado do Acre. A partir de 1988, algumas lideranças rurais e produtores do assentamento resolvem priorizar o uso alternativo da terra com Sistemas Agroflorestais – SAFs, tendo como base o consórcio de culturas perenes regionais (cupuaçu, pupunha, castanha-do-brasil) e café, e formaram a Associação de Pequenos Agrosilvicultores do Projeto de Reflorestamento Econômico Consorciado e Adensado, que passou a ser conhecida como Projeto RECA. Este projeto teve como objetivos organizar os produtores e a produção primária e secundária, com o beneficiamento e comercialização dos produtos. O objetivo deste estudo foi analisar a situação produtiva e socioeconômica das propriedades e dos agrosilvicultores sócios do Projeto RECA. Foi efetuada a seleção de 50 unidade produtivas de produtores rurais, representando aproximadamente 1/3 das unidades produtivas para a mensuração de variáveis sócio econômicas e ambientais, através de amostragem intencional estratificada, em Dezembro 2004 e Janeiro de 2005. As 240 famílias associadas ao RECA são, na maioria (75%), migrantes da região centro-sul; com uma média de 13 anos no RECA; residem no lote a mais de 18 anos, que tem em média 82 hectares, sendo que em cada unidade de produção há 1,4 lotes, com 115 hectares, dos quais 55% encontra-se em floresta nativa, 29% em pastagem, 8% com SAFs, 6% em capoeiras e 2% em outros usos. Os produtos que geram maior renda são o cupuaçu, pupunha (semente, fruto e palmito), café e gado bovino, que somados respondem por 90% da renda bruta anual média, que é de R$20.800,00. O modelo de organização sócio-econômica do projeto RECA propiciou a melhoria das condições de vida dos produtores e da conservação ambiental, comprovando que as políticas direcionadas à agricultura familiar cooperativada, tanto nos processos produtivos relacionados ao uso da terra, como no beneficiamento e comercialização da produção através de agroindústrias, propiciou o acesso ao crédito e tecnologias, possibilitando melhorias no sistema de produção e aumento no valor agregado dos produtos, com retornos sociais e econômicos relevantes, verificados pela elevação da renda e qualidade de vida dos agricultores.------------------------------------------------------------- ---Agricultural settlement of hundreds of thousands of families in the Amazon caused significant environmental and socioeconomic problems in the region. In 1994 the National Institute for Settlement and Agrarian Reform (INCRA) established the Alto Madeira Agricultural Settlement Project in Vila California, State of Rondonia, on the border with the State of Acre. Beginning in 1988 some rural leaders and farmers of this settlement decided to focus on alternative land uses with agroforestry systems based on intercropping of native species (cupuaçu, peach palm and brazil nut) and coffee and established the Association of Small Farmers and Agrosilviculturalists of the Economic, Intercropped and Dense Reforestation Project which became known as Projeto Reca. This project had as objectives the organization of the farmers, the establishment of the agroforestry systems, the industrial processing and marketing the processed products to the local, regional and national markets. The objective of this study was to analyze the productive and socioeconomic situation of the properties and of the farmers of Projeto Reca. Between December 2004 and January 2005, 50 productive units representing 33$ 20.800,00. The model of socioeconomic organization of Projeto Reca resulted in significant improvement of farmers living conditions and promoted environmental conservation. This shows that policies for associations of small farmers aiming at promoting alternative land uses such as agroforestry systems, including adequate technologies, accessible credit lines, industrial processing and marketing strategies can be effective in adding value to products and improving efficiency and profitability of production systems, resulting in significant and sustainable economic and social benefits measured by higher income and better living conditions of farmers of Projeto Reca.Sistemas Agroflorestais, Amazônia, socioeconomia, RECA, Agroforestry Systems, Amazon, Socioeconomy, RECA, Farm Management,

Geoprocessing and prevalence of incomplete prenatal booklets and gestational diabetes screening in a southern Brazilian University Hospital

Objective: to evaluate the prevalence of an incomplete prenatal booklet and gestational diabetes mellitus (GDM) screening of postpartum women in a southern Brazilian University Hospital, relating to the municipality of origin and the neighborhood in which they live. Methods: cross-sectional study, including 283 postpartum women, aged over 18 years and who had their births at the University Hospital of Santa Maria/Brazil from January to April 2015. An incomplete prenatal booklet was defined in the absence of any data referring to the obstetric history and the current pregnancy, as well as the lack of identification of the pregnant woman and the Health Unit where prenatal care was performed. For GDM screening, information on fasting blood glucose and risk factors collected from the postpartum women was used. The SPSS 20.0 program was used for descriptive statistics and the Geolocation maps were separated by municipalities of origin and by neighborhoods where the prenatal care of the puerperal women occurred and plotted according to the variables evaluated, using the ArcGIS 10.3 software. Results: the prevalence of an incomplete prenatal booklet was 79.2%, while prevalence of positive GDM screening was 73.9%. The geolocation pointed out 14 municipalities of origin and six neighborhoods where prenatal care had the highest prevalence of incomplete prenatal booklets. For GDM screening, spatial distribution showed ten municipalities of origin and four neighborhoods with a higher prevalence of positive screening for GDM. Conclusion: the geolocation showed that 14 municipalities of origin and six neighborhoods had the highest prevalence of incomplete prenatal booklets. In addition, ten municipalities of origin and four neighborhoods presented with higher prevalence of positive screening for GDM