Spin-polarized transport in ferromagnetic multilayered semiconductor nanostructures

The occurrence of inhomogeneous spin-density distribution in multilayered ferromagnetic diluted magnetic semiconductor nanostructures leads to strong dependence of the spin-polarized transport properties on these systems. The spin-dependent mobility, conductivity and resistivity in (Ga,Mn)As/GaAs,(Ga,Mn)N/GaN, and (Si,Mn)/Si multilayers are calculated as a function of temperature, scaled by the average magnetization of the diluted magnetic semiconductor layers. An increase of the resistivity near the transition temperature is obtained. We observed that the spin-polarized transport properties changes strongly among the three materials.Comment: 3 pages, 4 figure

The political economy of Brazilian cultural policy

This article provides an analysis of the effectiveness of cultural policy in Brazil under the Rouanet Law for the period 1993–2016. We find that the law, which provides tax incentives for donations to and sponsorships of the cultural sector, has exacerbated existing socio-economic inequalities, regional inequalities and inequalities between artistic genres. The gifts have predominantly gone to already successful projects, sometimes even already profitable projects. On the flip side, the gifts have primarily come from large, mostly partially state-owned, enterprises and act as the equivalent of a tax cut for these organisations. From the evidence, it is not clear that any particular market failure is alleviated through the Rouanet Law; instead, it seems that the system of indirect support led to strong control over the cultural sector by big business in Brazil. We use these findings to criticise much of the literature on cultural policy, which tends to take Western well-developed institutions for granted. We argue that this literature is ill-suited to capture the economy of Brazil and other ‘limited-access states’ because of its implicit assumption of a pre-existing ‘open-access state’

Identification and Structural Characterization of Interneurons of the Drosophila Brain by Monoclonal Antibodies of the Würzburg Hybridoma Library

Several novel synaptic proteins have been identified by monoclonal antibodies (mAbs) of the Würzburg hybridoma library generated against homogenized Drosophila brains, e.g. cysteine string protein, synapse-associated protein of 47 kDa, and Bruchpilot. However, at present no routine technique exists to identify the antigens of mAbs of our library that label only a small number of cells in the brain. Yet these antibodies can be used to reproducibly label and thereby identify these cells by immunohistochemical staining. Here we describe the staining patterns in the Drosophila brain for ten mAbs of the Würzburg hybridoma library. Besides revealing the neuroanatomical structure and distribution of ten different sets of cells we compare the staining patterns with those of antibodies against known antigens and GFP expression patterns driven by selected Gal4 lines employing regulatory sequences of neuronal genes. We present examples where our antibodies apparently stain the same cells in different Gal4 lines suggesting that the corresponding regulatory sequences can be exploited by the split-Gal4 technique for transgene expression exclusively in these cells. The detection of Gal4 expression in cells labeled by mAbs may also help in the identification of the antigens recognized by the antibodies which then in addition to their value for neuroanatomy will represent important tools for the characterization of the antigens. Implications and future strategies for the identification of the antigens are discussed

Anais do 1º Encontro de Iniciação Científica e de Extensão da Unila: "Conhecer e Transformar"

Anais do I Encontro de Iniciação Científica e de Extensão da Unila. Unila-Centro, Foz do Iguaçu, Estado do Paraná, 04 e 05 de junho de 2012A indissocialibidade entre as ações de ensino, pesquisa e extensão, cuja unidade caracteriza o processo pedagógico no ensino superior tem, neste evento, a manifestação da sua aplicabilidade. Os planos de trabalho e projetos de estudantes e orientadores de iniciação científica e extensão demarcam os processos formadores da capacidade de pensamento crítico dos futuros profissionais egressos de uma universidade inovadora. Neste processo, a iniciação científica tem a missão de aperfeiçoar a formação acadêmica e profissional de estudantes de graduação, que são introduzidos nos diferentes campos do Saber pelas disciplinas e projetos de pesquisa docente para serem capacitados a refletir sobre limitações das sociedades, formular e testar hipóteses, resolver problemas e situações colocadas tanto pela simples curiosidade humana de conhecer quanto pela necessidade social de transformar. Constitui-se na formulação de questionamentos, na aprendizagem da elaboração do objeto de pesquisa, escolha dos referenciais epistemológicos e metodológicos, busca de informações, sistematização da argumentação e produção de conhecimento. A extensão é, por natureza, de vocação transformadora da realidade social, cultural e ambiental. Demanda uma ação de pesquisa, que pode ser chamada de pesquisa-ação ou de observação. Envolve a todos, comunidade universitária e comunidade onde está inserida a Universidade, num processo de troca de saberes. Os saberes e conhecimentos adquiridos, bem como as tecnologias produzidas, fomentam resultados coletivos sempre e quando são transferidos sob os princípios da responsabilidade, cooperação, solidariedade, racionalidade e da inclusão. Espera-se que cada estudante desenvolva atitudes críticas e habilidades de pesquisador, tais como dedicação, criatividade, honestidade, ética e compromisso com a transformação da realidade. O I Encontro de Iniciação Científica e de Extensão da Unila colabora para a avaliação e a exposição pública dos resultados dos projetos. Será realizada uma conferência de abertura composta pelo Magnífico Reitor Pro tempore da Unila, Hélgio Trindade, pelo Pró-Reitor de Pesquisa e Pós-graduação, Andrea Ciacchi, pela Pró-Reitora de Extensão, Luisa Maria de Moura e Silva e pelo pesquisador Flávio Bortolozzi, para expor ao público o tema “Pesquisa no Meio Acadêmico e suas Oportunidades”. O evento contará ainda com a palestra da pesquisadora Laura Tavares Ribeiro Soares com o título “A Pesquisa na Extensão”.Universidade Federal da Integração Latino-Americana (UNILA

Rarity, Species Richness, and the Threat of Extinction—Are Plants the Same as Animals?

Assessment of conservation status is done both for areas or habitats and for species (or taxa). IUCN Red List categories have been the principal method of categorising species in terms of extinction risk, and have been shown to be robust and helpful in the groups for which they have been developed. A recent study highlights properties associated with extinction risk in flowering plants, focusing on the species-rich hot spot of the Cape region of South Africa, and concludes that merely following methods derived from studies of vertebrates may not provide the best estimates of extinction risk for plants. Biology, geography, and history all are important factors in risk, and the study poses many questions about how we categorise and assess species for conservation priorities

Search for sterile neutrino mixing in the MINOS long-baseline experiment

A search for depletion of the combined flux of active neutrino species over a 735 km baseline is reported using neutral-current interaction data recorded by the MINOS detectors in the NuMI neutrino beam. Such a depletion is not expected according to conventional interpretations of neutrino oscillation data involving the three known neutrino flavors. A depletion would be a signature of oscillations or decay to postulated noninteracting sterile neutrinos, scenarios not ruled out by existing data. From an exposure of 3.18×1020 protons on target in which neutrinos of energies between ~500¿¿MeV and 120 GeV are produced predominantly as ¿µ, the visible energy spectrum of candidate neutral-current reactions in the MINOS far detector is reconstructed. Comparison of this spectrum to that inferred from a similarly selected near-detector sample shows that of the portion of the ¿µ flux observed to disappear in charged-current interaction data, the fraction that could be converting to a sterile state is less than 52% at 90% confidence level (C.L.). The hypothesis that active neutrinos mix with a single sterile neutrino via oscillations is tested by fitting the data to various models. In the particular four-neutrino models considered, the mixing angles ¿24 and ¿34 are constrained to be less than 11° and 56° at 90% C.L., respectively. The possibility that active neutrinos may decay to sterile neutrinos is also investigated. Pure neutrino decay without oscillations is ruled out at 5.4 standard deviations. For the scenario in which active neutrinos decay into sterile states concurrently with neutrino oscillations, a lower limit is established for the neutrino decay lifetime t3/m3>2.1×10-12¿¿s/eV at 90% C.L

Neutrino and Antineutrino Inclusive Charged-current Cross Section Measurements with the MINOS Near Detector

The energy dependence of the neutrino-iron and antineutrino-iron inclusive charged-current cross sections and their ratio have been measured using a high-statistics sample with the MINOS Near Detector exposed to the NuMI beam from the Main Injector at Fermilab. Neutrino and antineutrino fluxes were determined using a low hadronic energy subsample of charged-current events. We report measurements of neutrino-Fe (antineutrinoFe) cross section in the energy range 3-50 GeV (5-50 GeV) with precision of 2-8% (3-9%) and their ratio which is measured with precision 2-8%. The data set spans the region from low energy, where accurate measurements are sparse, up to the high-energy scaling region where the cross section is well understood.Comment: accepted by PR