Quantum radiation pressure on a moving mirror at finite temperature

We compute the radiation pressure force on a moving mirror, in the nonrelativistic approximation, assuming the field to be at temperature $T.$ At high temperature, the force has a dissipative component proportional to the mirror velocity, which results from Doppler shift of the reflected thermal photons. In the case of a scalar field, the force has also a dispersive component associated to a mass correction. In the electromagnetic case, the separate contributions to the mass correction from the two polarizations cancel. We also derive explicit results in the low temperature regime, and present numerical results for the general case. As an application, we compute the dissipation and decoherence rates for a mirror in a harmonic potential well.Comment: Figure 3 replaced, changes mainly in Sections IV and V, new appendix introduced. To appear in Physical Review

Is anodal transcranial direct current stimulation a potential ergogenic resource for muscle strength and effort perception? A critical review

Nas últimas décadas, vários estudos estão investigando a dose-resposta ideal em termos de frequência, intensidade e volume de treinamento para alcançar o aumento da força muscular, tanto em atletas quanto em não atletas. A dose-resposta é fundamental para a prescrição do treinamento, uma vez que sua manipulação equivocada pode acarretar alto risco de desenvolvimento de lesões por esforços repetitivos, bem como pelo não desenvolvimento da força esperada. Em indivíduos com nível avançado de treinamento de força, é extremamente importante aumentar sua intensidade e volume de treinamento. Nesse sentido, com os avanços encontrados na área de treinamento de força e a necessidade de novas estratégias para otimizar ganhos de força, um novo método vem ganhando força na literatura, a estimulação transcraniana por corrente contínua (ETCC). Portanto, o objetivo deste estudo é analisar criticamente os efeitos do ETCC como potencial recurso ergogênico para a realização de força muscular e percepção de esforço, bem como se seu uso é ético ou não. Para tanto, foram pesquisadas as bases de dados Pubmed/Medline, ISI Web of Knowledge e Scielo, apenas em inglês, e com as palavras-chave: força muscular, resistência muscular, estimulação transcraniana por corrente contínua, ETCC. Nós comparamos o efeito do ETCC anódico (ETCC-a) com uma condição sham/controle nos resultados de ETCC para força muscular e percepção de esforço força muscular e percepção de esforço. Nenhum estudo menciona efeitos colaterais negativos da intervenção. Os dados mostram diferenças entre os estudos que investigam os estudos de avaliação da força muscular e resistência muscular, em termos do uso bem sucedido de ETCC. Estudos que investigaram a eficiência do ETCC na melhora da força muscular demonstraram efeitos positivos do ETCC-a em 66,7% dos parâmetros testados. Amaioria dos dados mostra consistentemente a influência do ETCC-a na força muscular, mas não no desempenho de resistênciaEn las últimas décadas, diversos estudios están investigando la dosis-respuesta ideal en cuanto a la frecuencia, intensidad y volumen de entrenamiento para alcanzar el aumento de fuerza muscular, sea en atletas y no atletas. La dosis-respuesta es fundamental para la prescripción de entrenamiento, pues su manipulación equivocada puede llevar a un alto de riesgo de desarrollo de lesiones por esfuerzo repetitivo, así como para el no desarrollo de la fuerza esperada. En sujetos con nivel avanzado de entrenamiento de fuerza es extremadamente importante aumentar su intensidad y volumen de entrenamiento. En este sentido, con los avances encontrados en el área de entrenamiento de fuerza y la necesidad de nuevas estrategias para optimizar las ganancias de fuerza, un nuevo método está ganando fuerza en la literatura, la estimulación transcraneal por corriente continua (ETCC). Por lo tanto, el objetivo del presente estudio es analizar de forma crítica los efectos de la ETCC como potencial recurso ergogénico al desempeño de fuerza muscular y percepción de esfuerzo, así como si su uso es ético o no. Por lo tanto, se realizó una búsqueda en las bases de datos Pubmed/Medline, ISI Web of Knowledge y Scielo, solamente en inglés y con las palabras clave: fuerza muscular, resistencia muscular, estimulación transcraneal de corriente continua, ETCC. Comparamos el efecto de la ETCC anódica (ETCC-a) a una condición sham/control sobre los resultados de la fuerza muscular y percepción de esfuerzo. Ningún estudio menciona efectos secundarios negativos de la intervención. Los datos muestran diferencias entre los estudios que investigan la fuerza muscular y los estudios de evaluación de resistencia muscular, en lo que se refiere al uso exitoso de la ETCC. Los estudios que investigan la eficiencia de la ETCC en la mejora de la fuerza muscular demuestran efectos positivos de la ETCC-a en el 66,7% de los parámetros probados. La mayoría de los datos muestran consistentemente influencia de la ETCC-a en la fuerza muscular, pero no en el rendimiento de resistencia.In the last decades, several studies are investigating the optimal dose-response in terms of frequency, intensity and volume of training to achieve increased muscle strength in both athletes and non-athletes. Dose-response is critical to the prescription of training, since its mismanagement may pose a high risk of developing repetitive strain injuries as well as failure to develop the expected strength. In individuals with advanced level of strength training, it is extremely important to increase their intensity and training volume. In this sense, with the advances in the area of strength training and the need for new strategies to optimize force gains, a new method is gaining strength in the literature, the transcranial direct current stimulation (tDCS). Therefore, the purpose of this study is to critically analyze the effects of tDCS as a potential ergogenic resource for achieving muscle strength and perceived exertion, as well as whether its use is ethical or not. To do so, we searched the databases Pubmed/Medline, ISI Web of Knowledge and Scielo, in English only, and with the keywords: muscle strength, muscular endurance, transcranial direct current stimulation, tDCS. We compared the effect of anodic tDCS (a-tDCS) with a sham/control condition on muscle strength and perceived exertion results. No study mentions the negative side effects of the intervention. The data show differences between studies investigating studies of muscle strength and muscle endurance in terms of the successful use of tDCS. Studies that investigated tDCS efficiency in improving muscle strength demonstrated positive effects of a-tDCS on 66.7% of the parameters tested. Most data consistently show the influence of a-tDCS on muscle strength, but not on resistance performance.info:eu-repo/semantics/publishedVersio

Inertial forces in the Casimir effect with two moving plates

We combine linear response theory and dimensional regularization in order to derive the dynamical Casimir force in the low frequency regime. We consider two parallel plates moving along the normal direction in $D-$dimensional space. We assume the free-space values for the mass of each plate to be known, and obtain finite, separation-dependent mass corrections resulting from the combined effect of the two plates. The global mass correction is proportional to the static Casimir energy, in agreement with Einstein's law of equivalence between mass and energy for stressed rigid bodies.Comment: 9 pages, 1 figure; title and abstract changed; to appear in Physical Review

Expression of methylthioadenosine phosphorylase (MTAP) in pilocytic astrocytomas

BACKGROUND/OBJECTIVES Pilocytic astrocytomas (PAs) are the most frequent astrocytomas in children and adolescents. Methilthioadenosine phosphorylase(MTAP) is a tumor-suppressor gene, the loss of expression of which is associated with a poor prognosis and better response to specific chemotherapy in leukemia and non-small-cell lung cancer. The expression of MTAP in brain tumors remains largely unknown and its biological role in PA is still unexplored. Our aims were to describe the immunohistochemical MTAP expression in a series of PAs and relate it to the clinicopathological features of the patients. METHODS We assessed MTAP expression on immunohistochemistry in 69 pediatric and adult patients with PA in a tissue microarray platform. RESULTS Retained expression of MTAP was seen in >85% of the tumors compared to in the nonneoplastic adjacent tissue. Only 3 supratentorial tumors showed a complete loss of MTAP expression. No significant association with clinicopathological features or overall survival of the patients was found. CONCLUSIONS MTAP expression is retained in PAs and is not an outcome predictor for these tumors. Nevertheless, a subset of patients with PAs exhibiting a loss of MTAP could potentially benefit from treatment with specific chemotherapy, especially when lesions are recurrent or surgical resection is not recommended.This study was partially supported by the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (2012/19590-0) and an HCB program of financial support (Programa de Apoio e Incentivo a Pesquisa)

Criação de abelhas (apicultura).

Elaboradas em linguagem simples e objetiva, as publicações abordam temas relacionados à agropecuária e mostram como otimizar a atividade rural. A criação de animais, técnicas de plantio, práticas de controle de pragas e doenças, adubação alternativa e fabricação de conservas de frutas são alguns dos assuntos tratados.bitstream/item/11943/2/00081610.pdfProjeto Minibibliotecas

Reactivity, performance, color and tenderness of meat from Zebu cattle finished in feedlot.

The objective of this study was to study the animal reactivity and correlate it with performance and meat quality of cattle finished in feedlots. A total of 20 animals of the Tabapuã breed and 20 animals of the Nellore breed were confined for 112 days: 28 days of adaptation and 84 days of data collection. Performance was determined by the average daily weight gain (ADG) and average dry matter intake (DMI) estimated through the use of indicators. On the 1st, 42nd and 84th days of the experiment, two methods were used to measure the animal reactivity: animal reactivity in mobile cage and visual reactivity during handling. The characteristics of meat quality were evaluated by the color, shear force and pH24 after slaughter (pH24). Through the study of correlation, the degree and direction of linear association on animal reactivity, performance and meat quality were established. Regression equations were generated for the parameters evaluated according to the values of animal reactivity. Correlations between mobile cage and visual reactivity were 0.77, 0.56 and 0.45 in the 1st, 2nd and 3rd evaluations, respectively. There was no correlation between animal reactivity and DMI. The correlations between ADG, pH24, and color with animal reactivity were -0.31, 0.40, 0.47 and -0.34, and -0.33 for mobile cage, 0.74, 0.71 and -0.51, for visual reactivity, respectively. The parameters of meat quality varied according to the reactivity. Undesirable values of pH24, animal reactivity and color were found when mobile cage reactivity was higher than 780, 590 and 540, respectively. In general, animals that show greater reactivity tend to have lower daily weight gain and lower meat quality. The reactivity can be used in animal breeding programs, in order to improve performance and meat quality of Zebu cattle finished in feedlot

Residual feed intake and its effect on carcass and meat characteristics of feedlot Zebu cattle.

the objective of this study was to evaluate the residual feed intake (RFI) and its relation with performance, carcass and meat characteristics of Zebu animals. A total of 40 Zebu steers with initial age of 18 months and initial live weight of 350 kg were confined in feedlot for 112 days. The average daily gain (ADG) and dry matter intake (DMI) were obtained every 14 days. Residual feed intake was determined by the difference between observed and predicted DMI, based on the metabolic weight and the ADG. Animals were classified into the RFI groups: high (>0.5 standard deviation of the mean - least efficient), medium (±0.5 standard deviation of the mean) and low (<0.5 standard deviation of the mean - most efficient). Daily cost with feeding and per kilogram of weight gain was determined. Characteristics of carcass (weight, yield, subcutaneous fat) meat (pH, shear force and color) were assessed. Animals with low RFI presented lower DMI. The variation in DMI between the low and the high RFI groups promoted difference in the daily cost with feeding and per kilogram of weight gain, with animals of low RFI presenting costs 5 and 9% lower, respectively. Carcass and meat characteristics differed over the RFI groups. The knowledge of the RFI of the animals enables a more efficient system, with reduction in the costs with feeding, without promoting alterations on the performance and carcass characteristics of the meat from Zebu animals

A Nonzero Gap Two-Dimensional Carbon Allotrope from Porous Graphene

Graphene is considered one of the most promising materials for future electronic. However, in its pristine form graphene is a gapless material, which imposes limitations to its use in some electronic applications. In order to solve this problem many approaches have been tried, such as, physical and chemical functionalizations. These processes compromise some of the desirable graphene properties. In this work, based on ab initio quantum molecular dynamics, we showed that a two-dimensional carbon allotrope, named biphenylene carbon (BPC) can be obtained from selective dehydrogenation of porous graphene. BPC presents a nonzero bandgap and well-delocalized frontier orbitals. Synthetic routes to BPC are also addressed.Comment: Published on J. Phys. Chem. C, 2012, 116 (23), pp 12810-1281

Search for low-mass WIMPs in a 0.6 kg day exposure of the DAMIC experiment at SNOLAB

We present results of a dark matter search performed with a 0.6 kg day exposure of the DAMIC experiment at the SNOLAB underground laboratory. We measure the energy spectrum of ionization events in the bulk silicon of charge-coupled devices down to a signal of 60 eV electron equivalent. The data are consistent with radiogenic backgrounds, and constraints on the spin-independent WIMP-nucleon elastic-scattering cross section are accordingly placed. A region of parameter space relevant to the potential signal from the CDMS-II Si experiment is excluded using the same target for the first time. This result obtained with a limited exposure demonstrates the potential to explore the low-mass WIMP region (<10 GeV/$c^{2}$) of the upcoming DAMIC100, a 100 g detector currently being installed in SNOLAB.Comment: 11 pages, 11 figure

Diagnóstico socioeconômico-cultural e ambiental dos municípios do Projeto Boa Esperança.

A Embrapa Meio-Norte, por iniciativa da Chesf, com a qual estabeleceu uma parceria, vem desenvolvendo o Projeto Boa Esperança, visando resultar na melhoria dos níveis de produtividade e renda da atividade agropecuária, de forma participativa, além da mitigação da degradação ambiental. A importância desse projeto baseia-se na interação entre pesquisadores, extensionistas, agricultores familiares e pescadores organizados das comunidades, objetos de intervenção por intermédio do processo de difusão e transferência de alternativas tecnológicas. O projeto é composto de vários planos de ação, dos quais um pretende avaliar os aspectos sociotécnico-culturaleconômicos dos membros das comunidades, objeto das ações propostas no projeto, bem como levantar e organizar um sistema de informação de mercado da produção agrícola familiar em apoio ao projeto na geração de renda. Para a realização dos objetivos propostos, o projeto prevê que sejam realizados três diagnósticos participativos, no início, no meio e no final da sua execução, nas diversas comunidades da área de sua abrangência, onde se pretende implementar as atividades, com aplicação de questionário sociotécnico-cultural-econômico para identificação dos tipos de sistemas praticados, evolução da adoção das tecnologias e resultados finais obtidos pelos agricultores familiares e pescadores. Este documento traz o resultado do trabalho de prospecção realizado nas comunidades do entorno da Barragem de Boa Esperança, o qual contém dados sobre o agricultor/pescador, sua família e suas atividades, considerando o momento inicial de implementação do projeto.bitstream/item/83619/1/Doc-202-Diagnostico-completo.pd