Experimental demonstration of a mu=-1 metamaterial lens for magnetic resonance imaging

In this work a mu=-1 metamaterial (MM) lens for magnetic resonance imaging (MRI) is demonstrated. MRI uses surface coils to detect the radiofrequency(RF) energy absorbed and emitted by the nuclear spins in the imaged object. The proposed MM lens manipulates the RF field detected by these surface coils, so that the coil sensitivity and spatial localization is substantially improved. Beyond this specific application, we feel that the reported results are the experimental confirmation of a new concept for the manipulation of RF field in MRI, which paves the way to many other interesting applications.Comment: 9 pages, 3 figure

The Timing of Nine Globular Cluster Pulsars

We have used the Robert C. Byrd Green Bank Telescope to time nine previously known pulsars without published timing solutions in the globular clusters M62, NGC 6544, and NGC 6624. We have full timing solutions that measure the spin, astrometric, and (where applicable) binary parameters for six of these pulsars. The remaining three pulsars (reported here for the first time) were not detected enough to establish solutions. We also report our timing solutions for five pulsars with previously published solutions, and find good agreement with past authors, except for PSR J1701-3006B in M62. Gas in this system is probably responsible for the discrepancy in orbital parameters, and we have been able to measure a change in the orbital period over the course of our observations. Among the pulsars with new solutions we find several binary pulsars with very low mass companions (members of the so-called "black widow" class) and we are able to place constraints on the mass-to-light ratio in two clusters. We confirm that one of the pulsars in NGC 6624 is indeed a member of the rare class of non-recycled pulsars found in globular clusters. We also have measured the orbital precession and Shapiro delay for a relativistic binary in NGC 6544. If we assume that the orbital precession can be described entirely by general relativity, which is likely, we are able to measure the total system mass (2.57190(73) M_sun) and companion mass (1.2064(20) M_sun), from which we derive the orbital inclination [sin(i) = 0.9956(14)] and the pulsar mass (1.3655(21) M_sun), the most precise such measurement ever obtained for a millisecond pulsar. The companion is the most massive known around a fully recycled pulsar.Comment: Published in ApJ; 33 pages, 5 figures, 7 table

Variação do pigmento antocianina em diferentes regiões do cacho de açaí.

O açaí processado nas amassadeiras ou em agroindústrias representa um dos alimentos mais populares da Região Amazônica, notadamente no Amapá, assim como abastecendo outros mercados nacionais e até internacionais. Além de representar fonte de nutriente, também é reconhecido pelas suas propriedades funcionais, através do pigmento antocianina, de efeito antioxidante. Um dos problemas observados no abastecimento do mercado de frutos de açaí é a restrição quanto à época de produção de frutos, definida em safras diferenciadas em áreas limítrofes dos estados do Amapá e Pará, levando consequentemente à escassez de frutos nas entressafras respectivas, com aumento de preço e diminuição da qualidade dos frutos. Um teste de progênies foi instalado pela Embrapa Amapá, em Mazagão, com materiais coletados no estuário amazônico, onde avaliou-se a qualidade do fruto, em relação ao teor de antocianina total em três regiões do cacho: início, meio e fim, para verificar a variabilidade de concentrações de antocianina durante a maturação dos frutos. A antocianina total foi extraída e determinada pelo método de Fuleki e Francis (1968), com modificações de Constant (2003), após um período de 24 horas de extração e os dados analisados pelo programa SAS 9.2 TS Level 2MO (STATISTICAL...2010). Somente os materiais que produzem na época de safra amapaense, apresentaram diferenciação significativa em relação ao teor de antocianina total no início do cacho (43,21 mg/100g fruto) em relação à região do meio (31,82 mg/100g fruto) e fim do cacho (27,50 mg/100g fruto), influenciado pelos índices de maturação variados. Frutos de açaizeiro oriundo de materiais que produzem na entressafra amapaense apresentaram índice de maturação homogêneo, com teores semelhantes em todo o cacho. Conclui-se que, em produção comercial objetivando a extração de maiores teores de antocianina total, e que produzem nas condições da safra amapaense, pode-se selecionar, preferencialmente, os frutos localizados na parte superior do cacho

Pulsar J0453+1559: A Double Neutron Star System with a Large Mass Asymmetry

To understand the nature of supernovae and neutron star (NS) formation, as well as binary stellar evolution and their interactions, it is important to probe the distribution of NS masses. Until now, all double NS (DNS) systems have been measured to have a mass ratio close to unity (q $\geq$ 0.91). Here we report the measurement of the individual masses of the 4.07-day binary pulsar J0453+1559 from measurements of the rate of advance of periastron and Shapiro delay: The mass of the pulsar is 1.559(5) $M_{\odot}$ and that of its companion is 1.174(4) $M_{\odot}$; q = 0.75. If this companion is also a neutron star (NS), as indicated by the orbital eccentricity of the system (e=0.11), then its mass is the smallest precisely measured for any such object. The pulsar has a spin period of 45.7 ms and a spin derivative of 1.8616(7) x$10^-19$; from these we derive a characteristic age of ~ 4.1 x $10^9$ years and a magnetic field of ~ 2.9 x $10^9$ G,i.e, this pulsar was mildly recycled by accretion of matter from the progenitor of the companion star. This suggests that it was formed with (very approximately) its current mass. Thus NSs form with a wide range of masses, which is important for understanding their formation in supernovae. It is also important for the search for gravitational waves released during a NS-NS merger: it is now evident that we should not assume all DNS systems are symmetric

Manual de perdas pós-colheita em frutos e hortaliças.

Produção e perdas de frutos e hortaliças no Brasil. Perdas: definição, tipos e causas. Alguns aspectos envolvidos no controle das perdas: pré-colheita; colheita; pós-colheita; embalagem; transporte; armazenamento. Aspectos de mercado.bitstream/item/33932/1/1997-DOC-0027.pd

Evolução e coexistência do serviço de mensagens SMS em IMS

De modo a conquistar a confiança e potenciar a aceitação e adesão dos utilizadores às Redes de Próxima Geração (RPG), é necessário garantir que os serviços mais populares das redes legadas (GSM/GPRS) continuam presentes. O Short Message Service (SMS) é um serviço de “dados”, extremamente rentável para as operadoras de telecomunicações, que permite a troca de mensagens curtas entre utilizadores de redes móveis, fixas e indirectamente também com utilizadores da internet. Como se revela essencial expandir este serviço para a RPG ou permitir a sua interacção com os novos serviços de mensagens, foi efectuado um estudo onde é abordada a coexistência do SMS e do serviço de Instant Messaging (IM) nas redes legadas e nas novas redes all-IP. Neste estudo, identificam-se as normas relevantes, os protocolos utilizados e seu funcionamento nos serviços de mensagens da rede IP Multimedia Subsystem (IMS), e a forma como podem ser utilizados para garantir a interoperabilidade com o SMS. Neste artigo apresenta-se o resultado do estudo efectuado, com o objectivo de facilitar a compreensão da solução para interoperabilidade proposta pelas entidades normalizadoras, clarificando os conceitos relacionados e facilitando, desta forma, o desenvolvimento de soluções de interoperabilidade entre serviços nas redes legadas e de próxima geração. Neste contexto, são descritos os serviços de mensagens da rede IMS e os componentes responsáveis por permitir a interoperabilidade com o SMS, em particular o seu módulo IP Short Message Gateway (IP-SM-GW)

Goals, Strategies and First Discoveries of AO327, the Arecibo All-Sky 327 MHz Drift Pulsar Survey

We report initial results from AO327, a drift survey for pulsars with the Arecibo telescope at 327 MHz. The first phase of AO327 will cover the sky at declinations of -1 to 28 degrees, excluding the region within 5 degrees of the Galactic plane, where high scattering and dispersion make low-frequency surveys sub-optimal. We record data from a 57 MHz bandwidth with 1024 channels and 125 us sampling time. The 60 s transit time through the AO327 beam means that the survey is sensitive to very tight relativistic binaries even with no acceleration searches. To date we have detected 44 known pulsars with periods ranging from 3 ms to 2.21 s and discovered 24 new pulsars. The new discoveries include three millisecond pulsars, three objects with periods of a few tens of milliseconds typical of young as well as mildly recycled pulsars, a nuller, and a rotating radio transient. Five of the new discoveries are in binary systems. The second phase of AO327 will cover the sky at declinations of 28 to 38 degrees. We compare the sensitivity and search volume of AO327 to the Green Bank North Celestial Cap survey and the GBT350 drift survey, both of which operate at 350 MHz.Comment: Accepted for publication in Ap

Co‐existing monophasic teratoma and uterine adenocarcinoma in a female dog

Ovarian teratomas are occasionally reported in dogs; the rarest type is the monophasic teratoma,composed of tissues originating from only one germ layer. Canine endometrial adenocarcinomas are also rare in dogs and mainly affect geriatric females. This report describes case of co-existing ovarian teratoma and uterine adenocarcinoma in a 10-year old nulliparous female Boxer presented with lethargy, anorexia and purulent vaginal discharge. Abdominal ultrasonography evidenced pyometra and a mass in the left ovary. This was composed of a uniform whitish tissue with multiple cystic structures. The histology revealed an atrophy of the ovarian parenchyma, compressed by a proliferation of well-differentiated nervous tissue staining positively to vimentin, S100 and neuronal specific enolase (NSE), and negatively to keratin and inhibin. The left uterine horn, whose diameter was markedly increased, showed foci of endometrial cellular atypia, evident nucleoli and mitoses, at light microscopy. To our best knowledge, this is the first report of a coexisting ovarian monophasic teratoma and endometrial adenocarcinoma, two rare reproductive neoplasia in dogs