2,579 research outputs found

    Dirac-Hestenes spinor fields in Riemann-Cartan spacetime

    Get PDF
    In this paper we study Dirac-Hestenes spinor fields (DHSF) on a four-dimensional Riemann-Cartan spacetime (RCST). We prove that these fields must be defined as certain equivalence classes of even sections of the Clifford bundle (over the RCST), thereby being certain particular sections of a new bundle named Spin-Clifford bundle (SCB). The conditions for the existence of the SCB are studied and are shown to be equivalent to the famous Geroch's theorem concerning to the existence of spinor structures in a Lorentzian spacetime. We introduce also the covariant and algebraic Dirac spinor fields and compare these with DHSF, showing that all the three kinds of spinor fields contain the same mathematical and physical information. We clarify also the notion of (Crumeyrolle's) amorphous spinors (Dirac-K\"ahler spinor fields are of this type), showing that they cannot be used to describe fermionic fields. We develop a rigorous theory for the covariant derivatives of Clifford fields (sections of the Clifford bundle (CB)) and of Dirac-Hestenes spinor fields. We show how to generalize the original Dirac-Hestenes equation in Minkowski spacetime for the case of a RCST. Our results are obtained from a variational principle formulated through the multiform derivative approach to Lagrangian field theory in the Clifford bundle.Comment: 45 pages, special macros kapproc.sty and makro822.te

    Proposal for a collaborative LCA data management methodological aproach for creating "nodes" in the brazilian national inventory database (SICV) Brasil.

    Get PDF
    Global Guidance proposes mechanisms for LCA studies and data management for improving interoperability, data exchange, accessibility and credibility of LCA databases. The PBACV (CONMETRO, 2010) has among its objectives to implement in Brazil a system capable of organizing, storing and disseminating information of LCIs. The Brazilian government responded to this demand through IBICT, which developed the SICV Brazil. For a LCI database to succeed, it is necessary to have primary data provided by the productive sector. The availability of data contributes to the growth of the country while benefiting the primary data providers, as society is increasingly attentive to the transparency and environmental awareness of companies. The management of LCA data is not a concern of national LCI databases alone. Other institutions also need to manage their LCA data independently of proprietary software, ensuring autonomy and sustainability for their operations. Keeping data on someone?s own infrastructure favors autonomy, but multiplies infrastructure investment and impairs interoperability. This research proposes a procedure for shared management of LCA data through the creation nodes, an instance of SICV Brazil for storing LCI data from private and public institutions. This procedure for shared management promoted the Brazilian National Inventory Database (SICV Brazil) and offered advanced information resources to institutions, such as Embrapa, without additional infrastructure and facilitating interoperability with other institutions. Authors believe that the creation of other instances of the SICV could contribute to the advance of LCA in Brazil

    Differential protection induced by immunization with variable doses of a Leishmania antigenic extract against Leishmania amazonensis.

    Get PDF
    Experimental vaccines have been developed to protect against leishmaniasis using the BALB/c mice model immunized with different immunogens, but an effective vaccine still does not exist. To determine factors inherent to immunogens that might abrogate vaccine-induced efficacy, our research sought to investigate the impact of immunization using variable doses (low, medium and high) of a known soluble Leishmania antigenic extracts (SLA), associated or not with alum, in order to determine the best dose of this vaccine immunogen able to induce the best level of protection in BALB/c mice against L. amazonensis infection. This work shows that the immunization´ model using a high inoculum (100 µg) of SLA results in the best level of protection against challenge. These mice presented significant reductions in the footpad swelling and parasite load; high levels of IFN-γ and IL-12, and low levels of IL-4, IL-10, TGF-β and Leishmania-specific IgG and IgE antibodies. Mice immunized with 50 µg of SLA present intermediate results of protection; on the other hand, mice immunized with 1 µg showed the worst results. Considering all the elements, it could be concluded that the model employing a high dose of SLA in BALB/c mice can bring about the development of a protective immune response in the animals, thus allowing for the protection against the disease. In addition, we understand that the definition of an ideal dose for each vaccine candidate appears to be fundamental to determining the phenotype of resistance and/or susceptibility in murine models to study leishmaniasis

    What Can We Do When All Collapses? Fatal Outcome of Collapsing Glomerulopathy and Systemic Lupus Erythematosus With Diffuse Alveolar Hemorrhage: Case Report

    Get PDF
    NTRODUCTION: Collapsing glomerulopathy (CG) is a rare form of glomerular injury. Although commonly associated with human immunodeficiency virus (HIV) infection, it can occur in association with systemic lupus erythematosus (SLE). CASE REPORT: We present the case of a 50-year-old man, with chronic kidney disease secondary to focal and segmental glomerulosclerosis, who received a cadaveric kidney transplant in 2007. There were no relevant intercurrences until May 2015, when he presented with nephrotic range proteinuria (± 4 g/d). A graft biopsy was performed and it did not show any significant pathological changes. In September, he developed a full nephrotic syndrome (proteinuria 19 g/d) and a graft biopsy was repeated. CG features were evident with a rich immunofluorescence. Antinuclear antibodies (ANA) and anti-double-stranded DNA (anti-dsDNA) antibodies were positive; the remaining immunologic study was normal. Viral markers for HIV, hepatitis C virus (HCV), and hepatitis B virus (HBV) were negative. The patient was treated with corticosteroid pulses and plasmapheresis (seven treatments). A rapid deterioration of kidney function was seen and he became dialysis dependent. He was discharged with a low-dose immunosuppressive treatment. In October, he was hospitalized with diffuse alveolar hemorrhage (DAH). The auto-immune study was repeated, revealing complement consumption and positive titers of ANA and Anti-dsDNA antibodies. Anti-neutrophil cytoplasmic antibodies (ANCAs) and antiglomerular basement membrane antibody (anti-GBM) were negative. Treatment with intravenous corticosteroids, plasmapheresis, and human immunoglobulin was ineffective and the outcome was fatal. CONCLUSION: This case report highlights the possible association of CG and SLE. To our knowledge, it is the first case of SLE presenting with CG and DAH, with the singularity of occurring in a kidney transplant recipient receiving immunosuppression.info:eu-repo/semantics/publishedVersio

    Coeficientes de produção e custos das atividades florestais em uma área de manejo florestal sustentável.

    Get PDF
    A Amazônia é um dos principais produtores de madeira tropical do mundo. Em meio a essa situação, o gerenciamento dos recursos florestais de forma sustentável é considerado um desafio. Pesquisas relacionadas à análise da viabilidade do MFS têm abordado aspectos técnico-científicos com informações importantes dos custos de produção. O objetivo da pesquisa foi estruturar e analisar os coeficientes de produção das atividades florestais e dos custos da produção de madeira em tora em uma área de manejo florestal sustentável sob regime de concessão florestal, na Amazônia

    Predictive modeling of Alfvén eigenmode stability in inductive scenarios in JT-60SA

    Get PDF
    The JT-60SA device offers unique conditions before ITER for the study of the interaction of energetic particles with plasma waves. With similar dimensions to JET, e.g., a major radius but with a slightly more elongated plasma volume, JT-60SA is used as a high-power device where additional heating power (including 10 MW of the 500 keV Neutral Beam Injection) of up to 41 MW and the potential for high non-inductive plasma current operation pave the path for numerous challenges in physics on MHD stability, in particular, when considering the effects of energetic particles. Several operational scenarios with ITER and DEMO-relevant plasma regimes, in terms of non-dimensional plasma parameters, are anticipated. In this work, the stability of Alfvén eigenmodes (AEs) in variants of two of the most relevant operational scenarios with single null is analyzed: a full Ip inductive scenario at high density (1.1 × 1020 m−3 on-axis electron density) and 5.48MA/2.05T toroidal plasma current and magnetic field, and an advanced (hybrid) scenario with an ion energy transport barrier (ITB) and 3.5MA/2.28T toroidal plasma current and magnetic field. The workflow included the CRONOS code to establish the scenario, the ASCOT code to calculate the slowing-down energetic particle distributions for a positive/negative ion source-based neutral beam, and the MISHKA/CASTOR-K suite to calculate the MHD spectra of AEs and the associated drive/damping contributions from the NBI energetic ions, as well as the thermal ion landau damping. The systematic analysis, over a large Fourier space of the toroidal mode number/mode frequency, provides evidence that although a significant fraction of supra-Alfvénic particles stemming from the negative ion source-based neutral beam (500 keV) can, in some cases, drive to AEs in both scenarios, it is not enough to overcome the thermal ion landau damping. In addition, the advanced scenario with ITB is shown to be stable against AEs localized in the vicinity of the barrier as well, offering good prospects of sustainability of the plasma performance and of ITB. Finally, some sensitivity scan results are shown on the influence of fast ion density and q-profile on the AE mode spectra and stability

    Results from the portuguese register

    Get PDF
    Objective Our aims were to evaluate the correlation between Juvenile Arthritis Disease Activity Score 27-joint reduced count (JADAS27) with erythrocyte sedimentation rate (ESR) and JADAS27 with C-reactive protein (CRP) scores and to test the agreement of both scores on classifying each disease activity state. We also aimed at verifying the correlation of the 2 scores across juvenile idiopathic arthritis (JIA) categories and to check the correlation between JADAS27-ESR and clinical JADAS27 (JADAS27 without ESR). Methods A nationwide cohort of patients with JIA registered in the Portuguese Register, Reuma.pt, was studied. JADAS27-CRP was adapted by replacing ESR with CRP level as the inflammatory marker. JADAS27-CRP was calculated similarly to JADAS27-ESR as the simple linear sum of its 4 components. Pearson's correlations and K statistics were used in the analyses. Results A total of 358 children had full data to calculate JADAS27; 65.4% were female and the mean ± SD disease duration was 11.8 ± 9.1 years. The correlation coefficient between JADAS27-ESR and JADAS27-CRP was 0.967 (P < 0.0001), although the correlation coefficient between ESR and CRP level was 0.335 (P < 0.0001). The strong correlation between JADAS27-ESR and JADAS27-CRP was maintained when compared within each JIA category. The agreement between JADAS27-ESR and JADAS27-CRP across the 4 activity states was very good, showing 91.1% of the observations in agreement; K = 0.867 (95% confidence interval 0.824-0.91). The correlation between JADAS27 with ESR and JADAS27 without ESR was high (r = 0.97, P < 0.0001). Conclusion JADAS27 based on CRP level correlated closely with JADAS27-ESR across all disease activity states and JIA categories, indicating that both measures can be used in clinical practice. Moreover, the correlation of JADAS27 with and without ESR was also high, suggesting that this tool might be useful even in the absence of laboratorial measures.publishersversionpublishe
    corecore