13,141 research outputs found

    Spectroscopic characterization of X-ray emitting young stars associated with the Sh 2-296 nebula

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    We studied a sample of stars associated with the Sh 2-296 nebula, part of the reflection nebulae complex in the region of Canis Major (CMa R1). Our sample corresponds to optical counterparts of X-ray sources detected from observations with the XMM-Newton satellite, which revealed dozens of possible low-mass young stars not yet known in this region. A sample of 58 young star candidates were selected based on optical spectral features, mainly H{\alpha} and lithium lines, observed with multi-objects spectroscopy performed by the Gemini South telescope. Among the candidates, we find 41 confirmed T Tauri and 15 very likely young stars. Based on the H{\alpha} emission, the T Tauri stars were distinguished between classical (17%) and weak-lined (83%), but no significant difference was found in the age and mass distribution of these two classes. The characterization of the sample was complemented by near- and mid-infrared data, providing an estimate of ages and masses from the comparison with pre-main-sequence evolutionary models. While half of the young stars have an age of 1-2 Myrs or less, only a small fraction (~25%) shows evidence of IR excess revealing the presence of circumstellar discs. This low fraction is quite rare compared to most young star-forming regions, suggesting that some external factor has accelerated the disc dissipation

    System and market failures: the unavailability of magnesium sulphate for the treatment of eclampsia and pre-eclampsia in Mozambique and Zimbabwe.

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    Low cost and effective drugs, such as magnesium sulphate, need to be included in initiatives to improve access to essential medicines in Afric

    Bilateral Breast Inflammatory Pseudotumor: A Clinical Report and Literature Review

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    Inflammatory pseudotumor (IP) is a benign lesion that can affect nearly any tissue in the body and which may be confused clinically and in imaging for malignancy. Despite the widespread performance of breast biopsy, the finding of inflammatory pseudotumor of the breast is exceedingly rare. Excision of the tumor is the treatment of choice, but there is a relatively high rate of recurrence. The aim of this report is to describe the clinical, imaging, and pathologic features in a case of bilateral breast IP

    Optical and Near Infrared Study of the Cepheus E outflow, a very low excitation object

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    We present images and spectra of the Cepheus E (Cep E) region at both optical and infrared wavelengths. Only the brightest region of the southern lobe of the Cep E outflow reveals optical emission, suggesting that the extinction close to the outflow source plays an important r\^ole in the observed difference between the optical and IR morphologies. Cep E is a unique object since it provides a link between the spectroscopic properties of the optical Herbig-Haro (HH) objects and those of deeply embedded outflows.Comment: Accepted Astron. J., 8 files: paper, tables plus 6 figure

    A comparative study of austenitic structure in NiTi and Fe based shape memory alloys after severe plastic deformation

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    The effect of high speed high pressure torsion (HS-HPT) was studied in NiTi and FeMnSiCr SMAs, by comparison. Severe plastic deformation was performed in austenite state for both types of alloys. The alloys subjected to HS-HPT, reduced their grain size due to microstructure fragmentation by compression and torsion. The active elements were achieved being able to support variable ranges of processing parameters like force, pressure, rotation speed and time of torsion. The evolution of microstructural refinement in the samples subjected to different deformation by HS-HPT, were studied by optical and scanning electron microscopy observation and the thermal effect was reveled using differential scanning calorimetry (DSC). (C) 2015 The Authors. Published by Elsevier Ltd.publishersversionpublishe

    Avaliação de cortes comerciais de cordeiros terminados em pastagem irrigada no Semiárido nordestino.

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    O objetivo desse estudo foi comparar quatro grupos genéticos de ovinos deslanados quanto aos pesos e rendimentos dos cortes comerciais da carcaça. Trinta e três cordeiros, contemporâneos, nascidos de parto simples e sem relação de parentesco foram utilizados no experimento, sendo treze da raça Santa Inês (SI), seis da raça Morada Nova (MN), sete da raça Somalis Brasileira (SB) e sete ½ Dorper ? ½ Morada Nova (F1). Os grupos genéticos Santa Inês, Somalis Brasileira e ½ Dorper ? ½ Morada Nova apresentaram médias similares para os cortes do pernil, lombo, costilhar, serrote e pescoço (p>0,05). Melhores rendimentos de pernil foram observados nos grupos Somalis Brasileira e Santa Inês, e melhores rendimentos de lombo foram observados nos grupos Somalis Brasileira e Morada Nova. A similaridade dos grupos Santa Inês, Somalis Brasileira e ½ Dorper ? ½ Morada Nova nos pesos dos cortes não se manteve nos rendimentos. Isso indica diferenças entre os grupos quanto à deposição de carne em cortes específicos. Evaluation of commercial cuts of lambs finished in irrigated pasture in the semiarid northeastern Brazil. Abstract: The aim of this study was to compare four genetic groups of hair sheep on the weight and yield of commercial cuts of carcass. Thirty-three male lambs, contemporary and unrelated were used in the experiment, being thirteen of Santa Inês (SI) breed, seven of Brazilian Somali breed (SB), six of Morada Nova (MN) breed and seven ½ Dorper x ½ Morada Nova (F1) crossbred. All lambs were of simple birth. The genetic groups Santa Inês, Somalis Brasileira and ½ Dorper - ½ Morada Nova had similar averages for leg, , loin, rib, foreshank and neck cuts (p>0,05). Best leg yields were observed in Brazilian Somali and Santa Ines groups, and better loin yields were observed in Brazilian Somalis and Morada Nova breeds. The similarity of groups Santa Inês, Somalis Brasileira and ½ Dorper - ½ Morada Nova in the weights of the cuts was not maintained in the yields. This indicates differences between groups in the deposition of meat in specific cuts

    Estádio de adaptação de Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) em hospedeiros alternativos.

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    A principal praga-alvo na cultura do milho é a lagarta-do-cartucho, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae), que, pela sua ampla distribuição temporal e geográfica constitui-se em uma das espécies mais nocivas nas regiões tropicais das Américas. O objetivo foi avaliar o estádio de adaptação de S. frugiperda em 17 espécies hospedeiras, cultivadas ou selvagens, mais comuns no agroecossistema brasileiro. As plantas foram cultivadas em cinco épocas, entre 2006 e 2008, utilizando o milho como ladrão. Larvas de S. frugiperda recém-eclodidas foram individualizadas e confinadas em copo plástico (50 mL), onde foram alimentadas com seções de folha nova de cada hospedeiro. O alimento foi substituído a cada dois dias por folhas frescas. Quatro variáveis biológicas foram avaliadas e utilizadas para se calcular um Índice de Adaptação (IA). Os resultados indicaram que a sobrevivência inicial de S. frugiperda variou de 100%, no milho, a 46%, no arroz. O período larval variou de 12,6 dias, no milho, a 27,1 dias, na grama batatais. A biomassa de pupa variou de 173,1 mg, no carrapicho, a 294,2 mg, no milho. O índice de adaptação, calculado com base nas variáveis biológicas de S. frugiperda, nos hospedeiros avaliados, variou de 17,43, no milho cultivado na época I, a 1,46, na cana-de-açúcar na época III. Para corrigir o efeito de época sobre o índice de adaptação de S. frugiperda nos hospedeiros, foi calculado o Índice Relativo de Adaptação (IRA), com base no índice de adaptação no milho (100%). Assim, com base no índice relativo de adaptação, estimado em condições de laboratório, os hospedeiros alternativos ao milho, para S. frugiperda, podem ser assim ordenados, do maior para o menor índice: sorgo granífero, sorgo selvagem, milheto, capim-tanzânia, amendoim, capim-marandu, capim-braquiária, caruru-de-porco, trigo, soja, algodão, feijão, arroz, capim-carrapicho, grama batatais e cana-de-açúcar

    Experimental observation of quantum entanglement in low dimensional spin systems

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    We report macroscopic magnetic measurements carried out in order to detect and characterize field-induced quantum entanglement in low dimensional spin systems. We analyze the pyroborate MgMnB_2O_5 and the and the warwickite MgTiOBO_3, systems with spin 5/2 and 1/2 respectively. By using the magnetic susceptibility as an entanglement witness we are able to quantify entanglement as a function of temperature and magnetic field. In addition, we experimentally distinguish for the first time a random singlet phase from a Griffiths phase. This analysis opens the possibility of a more detailed characterization of low dimensional materials
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