868 research outputs found
Impacts of climate changes on risk zoning for cowpea in the Amazonian tropical conditions
The climate risk zoning was carried out for cowpea cultivated in northeastern Amazonia, Pará state, Brazil. Système d’Analyse
Régionale des Risques Agroclimatologiques (SARRA) crop model was used and calibrated from data obtained in field experiments
conducted between 2013 and 2016 in Castanhal, state of Pará. Low climate risk areas were defined as those with water requirement
satisfaction index (WRSI) greater than or equal to 0.5 during flowering and early grain development and less than 20 mm of total rainfall
during grain maturation and harvest for at least 80% of the simulated sowings of the crop. Simulations of the current and future climate
conditions were carried out with the regional climate modelling system version 4 (RegCM4) nested with the HadGEM2 global circulation
model with RCP 4.5 IPCC-AR4 scenario. The results show that climate changes are likely to reduce the duration of the optimal period for
sowing cowpea in the mentioned regioninfo:eu-repo/semantics/publishedVersio
Quons as su(2) Irreducible Tensor Operators
We prove that, for the quon algebra, which interpolates between the Bose and
Fermi statistics and depends on a free parameter q,it is possible to build an
su(2) irreducible representation. One of the consequences of this fact is that
the quons couple via the same angular momentum coupling rules obeyed by
ordinary bosons and fermions.Comment: 8 pages,Late
Quons Restricted to the Antisymmetric Subspace: Formalism and Applications
In this work we develop a formalism to treat quons restricted to the
antisymmetric part of their many-body space. A model in which a system of
identical quons interact through a pairing force is then solved within this
restriction and the differences between our solution and the usual fermionic
model solution are then presented and discussed in detail. Possible connections
to physical systems are also considered.Comment: 12 pages, 3 figure
New <i>Penicillium</i> and <i>Talaromyces</i> species from honey, pollen and nests of stingless bees
Description Of Rhodnius Marabaensis Sp. N. (hemiptera, Reduviidade, Triatominae) From Pará State, Brazil
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Rhodnius marabaensis sp. n. was collected on 12 May 2014 in the Murumurú Environmental Reserve in the city of Marabá, Pará State, Brazil. This study was based on previous consultation of morphological descriptions of 19 Rhodnius species and compared to the identification key for the genus Rhodnius. The examination included specimens from 18 Rhodnius species held in the Brazilian National and International Triatomine Taxonomy Reference Laboratory in the Oswaldo Cruz Institute in Rio de Janeiro, Brazil. The morphological characteristics of the head, thorax, abdomen, genitalia, and eggs have been determined. Rhodnius prolixus and R. robustus were examined in more detail because the BLAST analysis of a cyt-b sequence shows they are closely related to the new species, which also occurs in the northern region of Brazil. The most notable morphological features that distinguish R. marabaensis sp. n. are the keel-shaped apex of the head, the length of the second segment of the antennae, the shapes of the prosternum, mesosternum and metasternum, the set of spots on the abdomen, the male genitalia, the posterior and ventral surfaces of the external female genitalia, and the morphological characteristics of the eggs. Rhodnius jacundaensis Serra, Serra and Von Atzingen (1980) nomen nudum specimens deposited at the Maraba Cultural Center Foundation - MCCF were examined and considered as a synonym of R. marabaensis sp. n. © Eder dos Santos Souza et al.201662145622010/15386-3, FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo23038-005285/2011-2012, CAPES, Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Aspectos técnico-ambientais da produção orgânica na região citrícola do Vale do Rio Caí, RS.
Há uma preocupação crescente sobre a necessidade de produção e consumo de alimentos mais saudáveis, sem uso de agrotóxicos nem fertilizantes sintético-industriais. Neste contexto se insere a prática da agricultura orgânica, que, contudo, apresenta resultados ainda pouco avaliados nos meios acadêmicos e científicos. Assim, pretendeu-se nesta pesquisa diagnosticar aspectos técnico-ambientais da produção orgânica na região citrícola do Vale do Rio Caí, no Rio Grande do Sul. Inicialmente, foram selecionadas propriedades de oito agricultores familiares, todas já convertidas ao sistema orgânico de produção, sendo aplicadas entrevistas semi-estruturadas. Os produtores mostram-se satisfeitos com o sistema orgânico de produção e revelam bom conhecimento sobre o ambiente, plantas, solos e processos agroecológicos, adquiridos através da participação em eventos técnicos e em reuniões da Cooperativa Ecocitrus. A constante troca de experiências entre esses agricultores tem melhorado sua qualificação técnica, além de melhor conscientizá-los nos aspectos políticos, econômicos e sociais
Bezerromycetales and Wiesneriomycetales ord. nov. (class Dothideomycetes), with two novel genera to accommodate endophytic fungi from Brazilian cactus
During a survey of endophytic fungi from the cactus Tacinga inamoena in a Brazilian tropical
dry forest (Caatinga) some undescribed ascomycetous fungi were isolated. These fungi are
characterized by superficial and immersed, globose to subglobose, smooth or hairy
ascomata, bitunicate asci, and muriformly septate, ellipsoidal ascospores. Multigene
phylogenetic analyses using sequences from partial ITS, SSU and LSU nrDNA and the
translation elongation factor 1-alpha gene (tef1) demonstrated a monophyletic clade
accommodating these endophytic fungi in the class Dothideomycetes, closely related to the
order Tubeufiales. Based on morphological features and phylogenetic analyses, these fungi
could not be placed in the order Tubeufiales, in the new order Wiesneriomycetales, or any
other known genus in the class Dothideomycetes. Thus, two new genera (Bezerromyces,
with B. brasiliensis and B. pernambucoensis, and Xiliomyces with X. brasiliensis), a new
family (Bezerromycetaceae) and a new order (Bezerromycetales) are introduced to
accommodate these novel taxa. Our phylogenetic analyses also demonstrated that the clade
accommodating Wiesneriomycetaceae represents a new order, here introduced as
Wiesneriomycetales.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (Process
203132/2014-9), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
and Fundação de Amparo à Ciência e Tecnologia de Pernambuco (FACEPE) of Brazil.http://link.springer.com/journal/115572018-04-30hb2017Microbiology and Plant Patholog
Evolution of the differential transverse momentum correlation function with centrality in Au+Au collisions at GeV
We present first measurements of the evolution of the differential transverse
momentum correlation function, {\it C}, with collision centrality in Au+Au
interactions at GeV. {\it C} exhibits a strong dependence
on collision centrality that is qualitatively similar to that of number
correlations previously reported. We use the observed longitudinal broadening
of the near-side peak of {\it C} with increasing centrality to estimate the
ratio of the shear viscosity to entropy density, , of the matter formed
in central Au+Au interactions. We obtain an upper limit estimate of
that suggests that the produced medium has a small viscosity per unit entropy.Comment: 7 pages, 4 figures, STAR paper published in Phys. Lett.
Single Spin Asymmetry in Polarized Proton-Proton Elastic Scattering at GeV
We report a high precision measurement of the transverse single spin
asymmetry at the center of mass energy GeV in elastic
proton-proton scattering by the STAR experiment at RHIC. The was measured
in the four-momentum transfer squared range \GeVcSq, the region of a significant interference between the
electromagnetic and hadronic scattering amplitudes. The measured values of
and its -dependence are consistent with a vanishing hadronic spin-flip
amplitude, thus providing strong constraints on the ratio of the single
spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated
by the Pomeron amplitude at this , we conclude that this measurement
addresses the question about the presence of a hadronic spin flip due to the
Pomeron exchange in polarized proton-proton elastic scattering.Comment: 12 pages, 6 figure
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