2,300 research outputs found

    Virtual bilepton effects in polarized Moller scattering

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    We investigate the indirect effects of heavy vector bileptons being exchanged in polarized Moller scattering, at the next generation of linear colliders. Considering both longitudinal and transverse beam polarization, and accounting for initial-state radiation, beamstrahlung and beam energy spread, we discuss how angular distributions and asymmetries can be used to detect clear signals of virtual bileptons, and the possibility of distinguishing theoretical models that incorporate these exotic particles. We then estimate 95% C.L. bounds on the mass of these vector bileptons and on their couplings to electrons.Comment: 19 pages, 10 figure

    A model for the Delta(1600) resonance and gamma N -> Delta(1600) transition

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    A covariant spectator constituent quark model is applied to study the gamma N -> Delta(1600) transition. Two processes are important in the transition: a photon couples to the individual quarks of the Delta(1600) core (quark core), and a photon couples to the intermediate pion-baryon states (pion cloud). While the quark core contributions are estimated assuming Delta(1600) as the first radial excitation of Delta(1232), the pion cloud contributions are estimated based on an analogy with the gamma N -> Delta(1232) transition. To estimate the pion cloud contributions in the gamma N -> Delta(1600) transition, we include the relevant intermediate states, pi-N, pi-Delta, pi-N(1440) and pi-Delta(1600). Dependence on the four-momentum transfer squared, Q2, is predicted for the magnetic dipole transition form factor, GM*(Q2), as well as the helicity amplitudes, A_1/2(Q2) and A_3/2(Q2). The results at Q2=0 are compared with the existing data.Comment: To appear in Phys. Rev. D. Version with small modifications. 14 pages, 6 figures and 3 table

    Doc management: Proposal for a doctoral management system

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    Control is an essential function for good management, for which a bureaucratic organization, that is, a system of rules, regularized procedures, division of responsibilities, and hierarchy, contributes. This paper addresses the issues related to a problem encountered in the management of doctorate students. Traditionally manual, this process is no longer efficient. This brings problems such as difficulty in searching a student’s file and its information, difficulty in noticing if a student is undocumented, or in figuring out what tasks must be completed and turned in and what dates to do so. The current system is prone to delays, errors and requires unnecessary effort. The goal of this work was to develop a proposal to solve the problems described, by means of an application, with a simple interface, that can manage, create and edit students, their information, their grades and their deliveries, manage, create and edit curricular units and the related information, manage create and edit academic teachers and their functions. In other words, it is intended that the application is able to facilitate the management of all course processes and document a student's academic path. This will provide workers with a better quality of life, reducing the probability of error and generating gains in quality and efficiency in the management of student processes, thus improving the professional life of those who use the application.info:eu-repo/semantics/acceptedVersio

    Energy metabolism in human pluripotent stem cells and their differentiated counterparts

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    Background: Human pluripotent stem cells have the ability to generate all cell types present in the adult organism, therefore harboring great potential for the in vitro study of differentiation and for the development of cell-based therapies. Nonetheless their use may prove challenging as incomplete differentiation of these cells might lead to tumoregenicity. Interestingly, many cancer types have been reported to display metabolic modifications with features that might be similar to stem cells. Understanding the metabolic properties of human pluripotent stem cells when compared to their differentiated counterparts can thus be of crucial importance. Furthermore recent data has stressed distinct features of different human pluripotent cells lines, namely when comparing embryo-derived human embryonic stem cells (hESCs) and induced pluripotent stem cells (IPSCs) reprogrammed from somatic cells. Methodology/Principal Findings: We compared the energy metabolism of hESCs, IPSCs, and their somatic counterparts. Focusing on mitochondria, we tracked organelle localization and morphology. Furthermore we performed gene expression analysis of several pathways related to the glucose metabolism, including glycolysis, the pentose phosphate pathway and the tricarboxylic acid (TCA) cycle. In addition we determined oxygen consumption rates (OCR) using a metabolic extracellular flux analyzer, as well as total intracellular ATP levels by high performance liquid chromatography (HPLC). Finally we explored the expression of key proteins involved in the regulation of glucose metabolism. Conclusions/Findings: Our results demonstrate that, although the metabolic signature of IPSCs is not identical to that of hESCs, nonetheless they cluster with hESCs rather than with their somatic counterparts. ATP levels, lactate production and OCR revealed that human pluripotent cells rely mostly on glycolysis to meet their energy demands. Furthermore, our work points to some of the strategies which human pluripotent stem cells may use to maintain high glycolytic rates, such as high levels of hexokinase II and inactive pyruvate dehydrogenase (PDH). © 2011 Varum et al

    Melhoramento genético, registro e proteção de cultivares de Coffea canephora para o Estado de Rondônia.

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    O melhoramento genético do Coffea canephora objetivando a seleção de genótipos de ‘Conilon’ e ‘Robusta’ mais produtivos, tolerantes aos principais patógenos e adaptados às condições edafoclimáticas da região é de grande importância para impactar a cadeia produtiva do café no Estado de Rondônia. Tão importante quanto a obtenção da cultivar, é o seu registro e/ou proteção. Todas essas etapas fazem parte do processo de desenvolvimento e lançamento da cultivar, para que a mesma seja disponibilizada aos agricultores.bitstream/item/57882/1/doc143-cafe.pd

    Hand-based multimodal identification system with secure biometric template storage

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    WOS:000304107200001This study proposes a biometric system for personal identification based on three biometric characteristics from the hand, namely: the palmprint, finger surfaces and hand geometry. A protection scheme is applied to the biometric template data to guarantee its revocability, security and diversity among different biometric systems. An error-correcting code (ECC), a cryptographic hash function (CHF) and a binarisation module are the core of the template protection scheme. Since the ECC and CHF operate on binary data, an additional feature binarisation step is required. This study proposes: (i) a novel identification architecture that uses hand geometry as a soft biometric to accelerate the identification process and ensure the system's scalability; and (ii) a new feature binarisation technique that guarantees that the Hamming distance between transformed binary features is proportional to the difference between their real values. The proposed system achieves promising recognition and speed performances on two publicly available hand image databases.info:eu-repo/semantics/acceptedVersio

    Como obter sucesso na cultura do feijoeiro no Estado de Minas Gerais.

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    Tem por finalidade difundir uma nova cultivar de feijão, a 'BRSMG Talismã', recomendada para o Estado de Minas Gerais, e fornecer sugestões de tecnologias que certamente deverão contribuir para o aumento da produtividade.bitstream/CNPAF/19513/1/circ_50.pd

    Avaliação de progênies precoces de feijoeiro oriundas de cinco ciclos de seleção recorrente.

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    O objetivo do trabalho foi a avaliação de progênies, oriundas de cinco ciclos de seleção recorrente para florescimento precoce, visando selecionar progênies que apresentem florescimento precoce, aliadas à demais características de interesse aos melhoristas
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