VLBA determination of the distance to nearby star-forming regions I. The distance to T Tauri with 0.4% accuracy

In this article, we present the results of a series of twelve 3.6-cm radio continuum observations of T Tau Sb, one of the companions of the famous young stellar object T Tauri. The data were collected roughly every two months between September 2003 and July 2005 with the Very Long Baseline Array (VLBA). Thanks to the remarkably accurate astrometry delivered by the VLBA, the absolute position of T Tau Sb could be measured with a precision typically better than about 100 micro-arcseconds at each of the twelve observed epochs. The trajectory of T Tau Sb on the plane of the sky could, therefore, be traced very precisely, and modeled as the superposition of the trigonometric parallax of the source and an accelerated proper motion. The best fit yields a distance to T Tau Sb of 147.6 +/- 0.6 pc. The observed positions of T Tau Sb are in good agreement with recent infrared measurements, but seem to favor a somewhat longer orbital period than that recently reported by Duchene et al. (2006) for the T Tau Sa/T Tau Sb system.Comment: 24 pages, 3 pages, AASTEX format, accepted for publication in Ap

A multidrug approach to modulate the mitochondrial metabolism impairment and relative oxidative stress in fanconi anemia complementation group a

Fanconi Anemia (FA) is a rare recessive genetic disorder characterized by aplastic anemia due to a defective DNA repair system. In addition, dysfunctional energy metabolism, lipid droplets accumulation, and unbalanced oxidative stress are involved in FA pathogenesis. Thus, to modulate the altered metabolism, Fanc-A lymphoblast cell lines were treated with quercetin, a flavonoid compound, C75 (4-Methylene-2-octyl-5-oxotetrahydrofuran-3-carboxylic acid), a fatty acid synthesis inhibitor, and rapamycin, an mTOR inhibitor, alone or in combination. As a control, isogenic FA cell lines corrected with the functional Fanc-A gene were used. Results showed that: (i) quercetin recovered the energy metabolism efficiency, reducing oxidative stress; (ii) C75 caused the lipid accumulation decrement and a slight oxidative stress reduction, without improving the energy metabolism; (iii) rapamycin reduced the aerobic metabolism and the oxidative stress, without increasing the energy status. In addition, all molecules reduce the accumulation of DNA double-strand breaks. Two-by-two combinations of the three drugs showed an additive effect compared with the action of the single molecule. Specifically, the quercetin/C75 combination appeared the most efficient in the mitochondrial and lipid metabolism improvement and in oxidative stress production reduction, while the quercetin/rapamycin combination seemed the most efficient in the DNA breaks decrement. Thus, data reported herein suggest that FA is a complex and multifactorial disease, and a multidrug strategy is necessary to correct the metabolic alterations

Comportamento da Macrofauna edáfica em diferentes modelos de arborização de cafeeiro Robusta (Coffea canephora) em Rondônia.

O levantamento da fauna edáfica do solo é uma forma indicada de avaliar a viabilidade em função do manejo deste tipo de sistema. O objetivo deste trabalho foi fazer um levantamento da ocorrência da macrofauna do solo em 05 (dez) propriedades cultivadas com o café Robusta (Coffea canephora) arborizado no município de Rolim de Moura, localizado na região da Zona da Mata/RO em duas épocas diferentes. Na época chuvosa e seca, as Ordens com maiores frequência de ocorrência foram Hymenoptera, Araneae, Coleoptera, Dermaptera, Orthoptera, Isoptera, Acari, Lithobiomorpha, Diptera, Hemiptera. Através do índice de diversidade de Shannon identificou-se propriedades com maior estabilidade, principalmente quando houve maior diversidade de espécies florestais nos SAFs. O manejo dos SAFs, o clima, a diversidade de espécies florestais e o tamanho das áreas amostradas possivelmente influenciam a diversidade de Ordens da macrofauna

Caracterização de dez áreas com café conilon arborizado na Zona da Mata de Rondônia.

A presente pesquisa faz parte de um projeto maior de manejo da lavoura cafeeira arborizada e objetivou identificar as principais espécies utilizadas na arborização de áreas com cafeeiro Robusta nos município de Rolim de Moura e Nova Brasilândia do Oeste. A pesquisa foi desenvolvida em dez propriedades, cinco por município, e constou da aplicação de um questionário sócio-econômico, no qual foram levantadas a área total de cada propriedade, área com café Robusta, área com a(s) espécie(s) arborizadora, número de plantas, produtividade e idade do cafeeiro. Em Rolim de Moura a área total das propriedades avaliadas com cafeeiro Robusta arborizado é de 7,9 ha, a produtividade média varia de 10 a 100 sacas/ha, a idade do cafeeiro varia de 5 a 15 anos. No município de Nova Brasilândia a área total com café nas propriedades analisadas é de 15, 58ha, produtividade variando de 9 a 85 sacas/ha, a idade do cafeeiro varia de 5 a 21 anos

Desfolhamento artificial durante a formação do botão floral do girassol

In order to quantify reductions in leaf area which can be tolerated by sunflower plants (Helianthus annuus L.), an experiment was carried out at the Estação Experimental Agronômica of Universidade Federal do Rio Grande do Sul, in Guaíba, RS, Brazil, during the 1982/83 growing season. Plants were defoliated in two dates during the budding stage: when inflorescence head was visible, but tightly surrounded by young leaves, and when inflorescence began to open, with ray florets visible. In each of those dates eight defoliation levels were applied: removal of the leaves of the upper, medium and lower thirds of plant, individually; combination of these levels two by two; removal of all leaves, and an undefoliated check. There were no signiticant differences between defoliation dates for grain yield, grain weight, grain number in heads and head diameter. However, plant height, dry weight of stem plus head, and leaf area index varied with defoliation dates. Ali defoliation levels decreased grain yield in relation to check, with reductions varying from 16 to 100%, except for treatments where leaves were removed from the lower third of the plant and from the medium third. The levels of leaf removal affected statistically all characteristics evaluated.Com o objetivo de quantificar reduções da área foliar que as plantas de girassol (Helianthus annuus L.) podem tolerar, foi desenvolvido um trabalho na Estação Experimental Agronômica da UFRS, em Guaíba, RS, em 1982/83.  As plantas foram desfolhadas em duas épocas durante o estádio de formação do botão floral, quando a inflorescência era visível, porém firmemente circundada por folhas jovens, e quando estavam começando a abrir as flores radiais. Em cada época, foram aplicados oito níveis de desfolhamento: remoção das folhas do terço superior, médio e inferior, individualmente; combinações dos terços, dois a dois; remoção de todas as folhas, e testemunha sem remoção de folhas. Não se observaram diferenças significativas entre épocas de desfolhamento para rendimento, peso de grãos, número de grãos por capítulo e diâmetro de capítulo. Entretanto, a estatura de plantas, peso seco de caule + capítulo e IAF mantido na planta variaram com a época de desfolhamento. Todos os níveis de desfolhamento reduziram o rendimento de grãos em relação à testemunha, com decréscimos variando de 16 a 100%, exceto os tratamentos com remoção das folhas do terço inferior e remoção das folhas do terço médio. Os níveis de remoção de folhas afetaram estatisticamente todas as características avaliadas

Nephron-sparing Techniques Independently Decrease the Risk of Cardiovascular Events Relative to Radical Nephrectomy in Patients with a T1a-T1b Renal Mass and Normal Preoperative Renal Function

The aim of the study was to test the effect of treatment type (nephron sparing surgery vs radical nephrectomy) on the risk of developing cardiovascular event (CVe) after accounting for individual cardiovascular risk. A multi-institutional collaboration including 1331 patients with a clinical T1a-T1b N0 M0 renal mass and normal renal function before surgery (defined as an estimated glomerular filtration rate 6560 ml/min/1.73 m2). We retrospectively colleted data on RN (n=462, 34.7%) or NSS (n=869, 65.3%) between 1987 and 2013. When stratifying for treatment type, the proportion of patients who experienced CVe at 1, 5, and 10 yr was 5.5%, 9.9%, and 20.2% for NSS patients compared to 8.7%, 15.6%, and 25.9%, respectively, for RN patients (p=0.001). In multivariate analyses, patients who underwent NSS showed a significantly lower risk of developing CVe compared with their RN counterparts after accounting for clinical characteristics and cardiovascular profile. Limitations include the retrospective design of the study. The risk of CVe after renal surgery is not negligible. Patients treated with NSS have roughly half the risk of developing CVe relative to their RN counterparts. After accounting for clinical characteristics, comorbidities, and cardiovascular risk at diagnosis, NSS independently decreases the risk of CVe relative to RN

The ACS Exams Institute Undergraduate Chemistry Anchoring Concepts Content Map I: General Chemistry

To provide tools for programmatic assessment related to the use of ACS Exams in undergraduate chemistry courses, the ACS Exams Institute has built a content map that applies to the entire undergraduate curriculum. At the top two levels, the grain size of the content classification is large and spans the entire undergraduate curriculum. At the bottom two levels, the grain size of the content is more fine and tuned to specific course levels of the curriculum. This paper presents all four levels of the map as identified for first-year general chemistry

Internet-das-Bionano-Coisas: Conectando-se às Nanomáquinas

The Internet-of-things attracts the attention of many researchers in computer networks with the challenge of providing connectivity to a huge quantity of devices. This reality can be further complicated once again with the recent proposed Internet-of-bionano-things. Nanomachines, natural or synthetic, will be able to communicate to each other and to the Internet through the means of communication systems that are being developed at the nano-scale with the goal of cooperatively executing complex tasks. This technology requires a complete revision of the TCP/IP architecture to accommodate the requirements and demands of the nanonetworks. This chapter aims at introducing this research field to the computer network community, presenting the different types of communicating networks, an initial reformulation of the TCP/IP architecture, research challenges and the applications for the nanonetworks. This technology enables a revolution in the society and affects directly areas, such as medicine, agriculture, pollution and even industry

Study of damage control systems for space station

Damage control systems for detecting and locating overboard and onboard leak and damage modes on space station