4,790 research outputs found

    Desempenho de borregos desmamados da raça Barriga Negra em Roraima.

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    bitstream/item/70404/1/DOC-47-2011-ID-108.pd

    Geometrical Aspects Of BRST Cohomology In Augmented Superfield Formalism

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    In the framework of augmented superfield approach, we provide the geometrical origin and interpretation for the nilpotent (anti-)BRST charges, (anti-)co-BRST charges and a non-nilpotent bosonic charge. Together, these local and conserved charges turn out to be responsible for a clear and cogent definition of the Hodge decomposition theorem in the quantum Hilbert space of states. The above charges owe their origin to the de Rham cohomological operators of differential geometry which are found to be at the heart of some of the key concepts associated with the interacting gauge theories. For our present review, we choose the two (1+1)(1 + 1)-dimensional (2D) quantum electrodynamics (QED) as a prototype field theoretical model to derive all the nilpotent symmetries for all the fields present in this interacting gauge theory in the framework of augmented superfield formulation and show that this theory is a {\it unique} example of an interacting gauge theory which provides a tractable field theoretical model for the Hodge theory.Comment: LaTeX file, 25 pages, Ref. [49] updated, correct page numbers of the Journal are give

    Tuberculosis screening in the European migrant population: a scoping review of current practices

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    Responding to a surge in new tuberculosis (TB) cases among migrants from high-incidence countries, low-incidence European nations have heeded World Health Organization recommendations by implementing TB screening in this population. This review aims to synthesise evidence on current screening strategies for active TB and latent tuberculosis infection (LTBI) in European high-income countries, and their main barriers and interventions. PubMed, Web of Science and Scopus were searched from March to April 2023, including articles in English, published in the last decade, pertaining to screening strategies for active TB or LTBI in Europe focused on migrants, excluding those exclusively composed of refugees, asylum seekers or other migrant populations. 32 studies fit the criteria. Screening in migrants varies between countries regarding timing, population, screening location and diagnosis. Furthermore, some barriers prevent migrants from benefiting from screening, namely physical, cultural and professional barriers. Additional research is needed to determine the patterns through which regular migrants adhere to current screening strategies in European countries. © ERS 2024

    Discovery of optical pulsations in V2116 Ophiuchi/GX 1+4

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    We report the detection of pulsations with 124\sim 124 s period in V2116 Oph, the optical counterpart of the low-mass X-ray binary GX 1+4. The pulsations are sinusoidal with modulation amplitude of up to 4% in blue light and were observed in ten different observing sessions during 1996 April-August using a CCD photometer at the 1.6-m and 0.6-m telescopes of Laborat\'orio Nacional de Astrof\'{\i}sica, in Brazil. The pulsations were also observed with the UBVRIUBVRI fast photometer. With only one exception the observed optical periods are consistent with those observed by the BATSE instrument on board the Compton Gamma Ray Observatory at the same epoch. There is a definite correlation between the observability of pulsations and the optical brightness of the system: V2116~Oph had RR magnitude in the range 15.315.515.3-15.5 when the pulsed signal was detected, and R=16.017.7R = 16.0-17.7 when no pulsations were present. The discovery makes GX 1+4 only the third of 35\sim 35 accretion-powered X-ray pulsars to be firmly detected as a pulsating source in the optical. The presence of flickering and pulsations in V2116 Oph adds strong evidence for an accretion disk scenario in this system. The absolute magnitude of the pulsed component on 1996 May 27 is estimated to be MV1.5M_V \sim -1.5. The implied dimensions for the emitting region are 1.1 R_{\sun}, 3.2 R_{\sun}, and 7.0 R_{\sun}, for black-body spectral distributions with T=105T = 10^5 K, 2×1042 \times 10^4 K, and 1×1041 \times 10^4 K, respectively.Comment: 9 pages, 3 figures in PostScript, latex, accepted for publication on the Astrophysical Journal Letter

    Nilpotent Symmetries For Matter Fields In Non-Abelian Gauge Theory: Augmented Superfield Formalism

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    In the framework of superfield approach to Becchi-Rouet-Stora-Tyutin (BRST) formalism, the derivation of the (anti-)BRST nilpotent symmetries for the matter fields, present in any arbitrary interacting gauge theory, has been a long-standing problem. In our present investigation, the local, covariant, continuous and off-shell nilpotent (anti-)BRST symmetry transformations for the Dirac fields (ψ,ψˉ)(\psi, \bar\psi) are derived in the framework of the augmented superfield formulation where the four (3+1)(3 + 1)-dimensional (4D) interacting non-Abelian gauge theory is considered on the six (4+2)(4 + 2)-dimensional supermanifold parametrized by the four even spacetime coordinates xμx^\mu and a couple of odd elements (θ\theta and θˉ\bar\theta) of the Grassmann algebra. The requirement of the invariance of the matter (super)currents and the horizontality condition on the (super)manifolds leads to the derivation of the nilpotent symmetries for the matter fields as well as the gauge- and the (anti-)ghost fields of the theory in the general scheme of the augmented superfield formalism.Comment: LaTeX file, 16 pages, printing mistakes in the second paragraph of `Introduction' corrected, a footnote added, these modifications submitted as ``erratum'' to IJMPA in the final for

    Produção integrada de melão nos polos Mossoró-Açu e Baixo Jaguaribe: diagnóstico das conformidades e não conformidades com os requisitos do sistema.

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    Área geográfica e levantamento de informações; Práticas e procedimentos utilizados na pré-colheita; Recursos naturais; Material propagativo; Implantação da cultura; Nutrição de plantas; Manejo do solo; Irrigação e drenagem; Manejo da planta; Proteção integrada da planta; Sistema de registro; Práticas e procedimentos utilizados na colheita e pós-colheita; Processos de empacotadoras.bitstream/CNPAT-2010/12002/1/Doc-122.pd
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