4,790 research outputs found
Desempenho de borregos desmamados da raça Barriga Negra em Roraima.
bitstream/item/70404/1/DOC-47-2011-ID-108.pd
Geometrical Aspects Of BRST Cohomology In Augmented Superfield Formalism
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 -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
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
We report the detection of pulsations with 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
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 magnitude in the range when the pulsed
signal was detected, and when no pulsations were present. The
discovery makes GX 1+4 only the third of 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 . 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 K, K, and 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
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 are derived in the framework of the augmented
superfield formulation where the four -dimensional (4D) interacting
non-Abelian gauge theory is considered on the six -dimensional
supermanifold parametrized by the four even spacetime coordinates and a
couple of odd elements ( and ) 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.
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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