A search for VHE counterparts of Galactic Fermi bright sources and MeV to TeV spectral characterization

Very high-energy (VHE; E>100 GeV) gamma-rays have been detected from a wide range of astronomical objects, such as pulsar wind nebulae (PWNe), supernova remnants (SNRs), giant molecular clouds, gamma-ray binaries, the Galactic Center, active galactic nuclei (AGN), radio galaxies, starburst galaxies, and possibly star-forming regions as well. At lower energies, observations using the Large Area Telescope (LAT) onboard Fermi provide a rich set of data which can be used to study the behavior of cosmic accelerators in the MeV to TeV energy bands. In particular, the improved angular resolution of current telescopes in both bands compared to previous instruments significantly reduces source confusion and facilitates the identification of associated counterparts at lower energies. In this paper, a comprehensive search for VHE gamma-ray sources which are spatially coincident with Galactic Fermi/LAT bright sources is performed, and the available MeV to TeV spectra of coincident sources are compared. It is found that bright LAT GeV sources are correlated with TeV sources, in contrast to previous studies using EGRET data. Moreover, a single spectral component seems unable to describe the MeV to TeV spectra of many coincident GeV/TeV sources. It has been suggested that gamma-ray pulsars may be accompanied by VHE gamma-ray emitting nebulae, a hypothesis that can be tested with VHE observations of these pulsars.Comment: Astronomy and Astrophysics, in press, 17 pages, 12 figures, 5 table

PSR J1740+1000: A Young Pulsar Well Out Of The Galactic Plane

We discuss PSR J1740+1000, one of five pulsars recently discovered in a search of 470 square degrees at 430 MHz during the upgrade of the 305-m Arecibo telescope. The period of 154 ms and period derivative of 2.1 x 10^-14 s/s imply a spin-down age of 114 kyr that is smaller than 95% of all known pulsars. The youth and proximity of this pulsar make it a good candidate for detection at X-ray and gamma-ray energies. Its high Galactic latitude of 20.4 degrees suggests a very high velocity if the pulsar was born in the midplane of the Galaxy and if its kinematic age equals its spindown age. Interstellar scintillations, however, suggest a much lower velocity. We discuss possible explanations for this discrepancy, taking into account (a) possible birth sites away from the midplane; (b) contributions from the unmeasured radial velocity; (c) a kinematic age different from the spin-down age; and (d) biasing of the scintillation velocity by enhanced scattering from the North Polar Spur.Comment: 27 pages, 9 figures, submitted to Ap

High-speed video and electromagnetic analysis of two natural bipolar cloud-to-ground lightning flashes

High-speed video records of two bipolar cloud-to-ground flashes were analyzed in detail.\ud They both began with a single positive return stroke that was followed by more than one subsequent weak\ud negative stroke. Due to the elevated cloud base height of its parent thunderstorm, the preparatory processes\ud of each subsequent negative stroke were documented optically below cloud base. In the first event (Case 1) it\ud was observed that all four subsequent negative strokes were initiated by recoil leaders that retraced one\ud horizontal channel segment previously ionized by the positive leader. Those recoil leaders connected to the\ud original vertical channel segment and propagated toward ground, producing four subsequent strokes that\ud had the same ground contact point as the original positive discharge. The second event (Case 2), in contrast,\ud presented 15 subsequent strokes that were initiated by recoil leaders that did not reach the original channel\ud of the positive stroke. They diverged vertically toward ground, making contact approximately 11 km away\ud from the original positive strike point. These results constitute the first optical evidence that both single- and\ud multiple-channel bipolar flashes occur as a consequence of recoil leader activity in the branches of the initial\ud positive return stroke. For both events their total channel length increased continuously at a rate of the order\ud of 104 m s 1, comparable to speeds reported for typical positive leaders.FAPESP - 08/56711-4, 2010/01742-2FAPESP - CHUVA project - 2009/15235-8UNIVAP - Universidade do Vale do Paraíb

Differential Effects of Aging on Fore– and Hindpaw Maps of Rat Somatosensory Cortex

Getting older is associated with a decline of cognitive and sensorimotor abilities, but it remains elusive whether age-related changes are due to accumulating degenerational processes, rendering them largely irreversible, or whether they reflect plastic, adaptational and presumably compensatory changes. Using aged rats as a model we studied how aging affects neural processing in somatosensory cortex. By multi-unit recordings in the fore- and hindpaw cortical maps we compared the effects of aging on receptive field size and response latencies. While in aged animals response latencies of neurons of both cortical representations were lengthened by approximately the same amount, only RFs of hindpaw neurons showed severe expansion with only little changes of forepaw RFs. To obtain insight into parallel changes of walking behavior, we recorded footprints in young and old animals which revealed a general age-related impairment of walking. In addition we found evidence for a limb-specific deterioration of the hindlimbs that was not observed in the forelimbs. Our results show that age-related changes of somatosensory cortical neurons display a complex pattern of regional specificity and parameter-dependence indicating that aging acts rather selectively on cortical processing of sensory information. The fact that RFs of the fore- and hindpaws do not co-vary in aged animals argues against degenerational processes on a global scale. We therefore conclude that age-related alterations are composed of plastic-adaptive alterations in response to modified use and degenerational changes developing with age. As a consequence, age-related changes need not be irreversible but can be subject to amelioration through training and stimulation

COD REMOVAL OF PARBOILIZED RICE WASTEWATER BY CYANOBACTERIA APHANOTHECE MICROSCOPICA NÄGELI / REMOÇÃO DE DQO DO EFLUENTE DA PARBOILIZAÇÃO DO ARROZ PELA CIANOBACTÉRIA APHANOTHECE MICROSCOPICA NÄGELI

Cyanobacteria are photosynthetic prokaryotes organisms used on single-cell protein production and wastewater treatment for nitrogen and phosphorus removal. Moreover, some strains have the particular characteristic of growing in the dark on simple molecules such as acetate, glucose and organic acids, and consequently reduction of Chemical Oxygen Demand (COD) from nutrient medium. Aphanothece microscopica Nägeli is a cyanobacteria frequently found in south of Brazil, which has been studied with respect to residues valorization in the single-cell protein production. Wastewater from rice parboilization process presents characteristics that suggest the removal of nutrients and organic matterby incorporation into a biomass. The aim of this paper is to extend the findings of the previous studies about heterotrophic metabolism application of these cyanobacteria on wastewater treatment, considering influence of temperature and inoculum amount. Experiments indicated that Aphanothece microscopicaNägeli presented high potential of organic matter removal from parboilized rice effluent by 300 mgL-1 inoculum at temperature range 25-35oC.</p

Perfil sensorial de iogurte light, sabor pêssego Sensory profile of peach flavored light yogurt

Foi determinado o perfil sensorial descritivo de três amostras de iogurte light, sabor pêssego, pela metodologia fundamentada na Análise Descritiva Quantitativa (ADQ). A equipe sensorial definiu os termos descritores, os materiais de referência para o treinamento das qualidades e quantificações de cada um dos termos e a ficha de avaliação das amostras, de forma consensual. Dez provadores foram selecionados e rigorosamente treinados para compor a equipe definitiva, utilizando-se como critérios o poder discriminativo, reprodutibilidade e consenso dos provadores entre si. Foram gerados doze termos descritores pelo método de rede. A intensidade de cada descritor foi avaliada em cada amostra por escala não estruturada de nove centímetros, com termos de intensidade ancorados em seus extremos, sendo o mínimo à esquerda e o máximo à direita. Os dados foram analisados por ANOVA, Teste de Tukey e Análise de Componentes Principais (ACP). Os resultados indicaram que as amostras comerciais apresentaram grande variação em seus perfis sensoriais. Na ACP, ficou evidenciado que a amostra A foi caracterizada principalmente pelos atributos gosto doce, sabor pêssego e firmeza dos pedaços de fruta. A amostra B foi caracterizada pelos atributos brilho, cor pêssego e cremosidade, e a amostra C foi caracterizada pela maior intensidade dos atributos gosto ácido, adstringência, textura farinácea e aroma artificial de pêssego. De acordo com o teste de aceitação, todas as amostras apresentaram boa aceitação em todos os atributos avaliados. Desta maneira, a análise do perfil sensorial da amostra C, que contém proteína de soja na sua formulação, revelou que este ingrediente não foi percebido pelos provadores, e não interferiu na sua aceitação.<br>The descriptive terminology and sensory profile of three samples of peach flavored light yogurt were determined using methodology based on the Quantitative Descriptive Analysis (QDA). A sensory panel consensually defined sensory descriptors, their respective reference materials and the descriptive evaluation ballot. Ten individuals were selected as judges and trained. They used the following as criteria: discriminant power, reproducibility and individual consensus. Twelve descriptors were devised showing similarities and differences among the light yogurt samples. Each descriptor was evaluated using a nine-centimeter non-structured scale with the intensity terms anchored at its ends. The data were analysed by ANOVA, the Tukey test and the Principal Component Analysis (PCA). The results showed a great difference in the sensory profile of light yogurts, where sample C showed more variation. The PCA showed sample A to be more distinguished by the sweetness, flavor of peach and firmness of fruit pieces. Sample B was characterized by the brightness, peach color and creamy aspect. Sample C had a higher intensity of sourness and astringency, a more farinaceous texture and more artificial aroma of peach. According to the acceptability test, all the products were accepted positively for all evaluated attributes. Sample C which contains soy protein in its formulation showed that this ingredient was not noticed by the judges and did not interfere in it being accepted