12,474 research outputs found
Studies of the photoionization cross sections of CH_4
We present cross sections and asymmetry parameters for photoionization of the 1t_2 orbital of CH_4 using static‐exchange continuum orbitals of CH^+_4 to represent the photoelectron wave function. The calculations are done in the fixed‐nuclei approximation at a single internuclear geometry. To approximate the near‐threshold behavior of these cross sections, we assumed that the photoelectron spectrum is a composite of three electronic bands associated with the Jahn–Teller components of the distorted ion. The resulting cross sections reproduce the sharp rise seen at threshold in the experimental data and are in good agreement with experiment at higher energy. The agreement between the calculated and measured photoelectron asymmetry parameters is, however, less satisfactory
Estimations for the Single Diffractive production of the Higgs boson at the Tevatron and the LHC
The single diffractive production of the standard model Higgs boson is
computed using the diffractive factorization formalism, taking into account a
parametrization for the Pomeron structure function provided by the H1
Collaboration. We compute the cross sections at next-to-leading order accuracy
for the gluon fusion process, which includes QCD and electroweak corrections.
The gap survival probability () is also introduced to account for
the rescattering corrections due to spectator particles present in the
interaction, and to this end we compare two different models for the survival
factor. The diffractive ratios are predicted for proton-proton collisions at
the Tevatron and the LHC for the Higgs boson mass of = 120 GeV.
Therefore, our results provide updated estimations for the diffractive ratios
of the single diffractive production of the Higgs boson in the Tevatron and LHC
kinematical regimes.Comment: 20 pages, 6 figures, 3 table
Modelling microbial exchanges between forms of soil nitrogen in contrasting ecosystems
Although nitrogen (N) is often combined with carbon (C) in organic
molecules, C passes from the air to the soil through plant photosynthesis,
whereas N passes from the soil to plants through a chain of microbial
conversions. However, dynamic models do not fully consider the
microorganisms at the centre of exchange processes between organic and
mineral forms of N. This study monitored the transfer of <sup>14</sup>C and
<sup>15</sup>N between plant materials, microorganisms, humified compartments, and
inorganic forms in six very different ecosystems along an altitudinal
transect. The microbial conversions of the <sup>15</sup>N forms appear to be
strongly linked to the previously modelled C cycle, and the same equations
and parameters can be used to model both C and N cycles. The only
difference is in the modelling of the flows between microbial and inorganic
forms. The processes of mineralization and immobilization of N appear to be
regulated by a two-way microbial exchange depending on the C : N ratios of
microorganisms and available substrates. The MOMOS (Modelling of Organic Matter of Soils) model has already been
validated for the C cycle and also appears to be valid for the prediction of
microbial transformations of N forms. This study shows that the hypothesis
of microbial homeostasis can give robust predictions at global scale.
However, the microbial populations did not appear to always be independent
of the external constraints. At some altitudes their C : N ratio could be
better modelled as decreasing during incubation and increasing with
increasing C storage in cold conditions. The ratio of potentially
mineralizable-<sup>15</sup>N/inorganic-<sup>15</sup>N and the <sup>15</sup>N stock in the
plant debris and the microorganisms was modelled as increasing with altitude,
whereas the <sup>15</sup>N storage in stable humus was modelled as decreasing with
altitude. This predicts that there is a risk that mineralization of organic
reserves in cold areas may increase global warming
On the variability of HD 170699 - a possible COROT target
We present the analysis of the variability of HD 170699, a COROT star showing
the characteristics of a non evolutionary Delta Scuti star with high rotational
velocity. There is a clear period of 10.45 c/d with 5.29 mmag amplitude in the
y filter. From the data, it can be seen that the star shows multi-periodicity
and it is necessary to add more frequencies to adjust the observationsComment: To appear in RevMexAA(SC) in Proceedings of XII Reunion Regional
Latinoamericana de la UAI held in Isla Margarita, Venezuela, October 22-26,
200
The new automated daily mortality surveillance system
The experience reported in an earlier Eurosurveillance issue on a fast method to evaluate the impact of the 2003 heatwave on mortality in Portugal, generated a daily mortality surveillance system (VDM) that has been operating ever since jointly with the Portuguese Heat Health Watch Warning System. This work describes the VDM system and how it evolved to become an automated system operating year-round, and shows briefly its potential using mortality data from January 2006 to June 2009 collected by the system itself. The new system has important advantages such as: rapid information acquisition, completeness (the entire population is included), lightness (very little information is exchanged, date of death, age, sex, place of death registration). It allows rapid detection of impacts (within five days) and allows a quick preliminary quantification of impacts that usually took several years to be done. These characteristics make this system a powerful tool for public health action. The VDM system also represents an example of inter-institutional cooperation, bringing together organisations from two different ministries, Health and Justice, aiming at improving knowledge about the mortality in the population
Produção de sucos de acerola e caju e de repositor hidroeletrolítico clarificados por membranas.
bitstream/item/100363/1/2007-DOC-0078.pd
Misdiagnosis of leprosy in Brazil in the period 2003-2017: spatial pattern and associated factors
BACKGROUND: Leprosy causes a range of symptoms, and most diagnoses are established based on the clinical picture. Therefore, false negative and positive diagnoses are relatively common. We analyzed the spatial pattern of leprosy misdiagnosis and associated factors in Brazil. METHOD: Exploratory analyses of Kernel density of the new case detection rate (NCDR) and proportion of misdiagnosis in Brazil, 2003 - 2017. Factors associated with misdiagnosis were identified by logistic regression at the 5% significance level. RESULT: A total of 574,181 new leprosy cases were recorded in Brazil, of which 7,477 (1.3%) were misdiagnoses. No spatial correlation was observed between the proportion of misdiagnoses and the NCDR. The likelihood of misdiagnosis was elevated for females [OR: 1.58 (1.51 - 1.66)], children [OR: 1.49 (1.36 - 1.64)]; paucibacillary [OR: 1.08 (1.02 - 1.13)], indeterminate clinical forms [OR: 2.37 (2.15 - 2.62)], for cases diagnosed in the frame of mass screenings [OR: 3.36 (3.09- 3.73)] and contact examination [OR: 2.30 (2.13 - 2.49)] and for cases with affected nerves but no skin lesions [OR: 2.47(2.19 - 2.77)] when compared with those presenting both skin lesion and affected nerves. CONCLUSION: Misdiagnosis of leprosy is not correlated with the endemicity level in Brazil but rather with personal, diagnosis-related and disease characteristics
Relatório técnico da Embrapa Gado de Leite 1999-2000.
Núcleos temáticos:Resultados de pesquisa por Núcleo Temático da Embrapa Gado de Leite; Núcleo Temático Biogenética Animal Projetos: Marcadores genéticos associados às características de resistência a endo e ectoparasitos e ao estresse térmico em bovinos de leite; Organização do sistema de avaliação genética das raças de bovinos de leite no Brasil; Otimização do ganho genético em rebanhos zebus leiteiros; Otimização das técnicas de transferência de embrião e produção in vitro de embrião na raça Gir; SeJeção nas raças Holandesa e Girolando, Publicações geradas pelo Núcleo Temático; Núcleo Temático Biogenética de Forrageiras Projetos: Banco Ativo de Germoplasma de Capim-elefante e Alfafa; Identificação e ava\iação in vitro de clones de capim-elefante para tolerância ao estresse hídrico; Melhoramento genético do capim-elefante (P. purpureum Schum.) e da alfafa (M. sativa L.) para diferentes condições edafoclimáticas; Publicações geradas pelo Núcleo Temático; Núcleo Temático Sistemas de Alimentação -Projetos: Avaliação de milho e sorgo para silagem; Desenvolvimento de cultivares de sorgo; Publicações geradas pelo Nucleo Temático; Núcleo Temático Sustentabilidade da Atividade Leiteira -Projetos: Estratégias de manejo nutricional de vacas leiteiras em pastagens de capim-elefante; Inserção da fixação biológica de nitrogênio na recuperação de áreas degradadas e na sustentabilidade e produtividade de solos tropicais; Sistemas alternativos de produção de leite a pasto sob manejo intef)sivo; Zoneamento bioclimatológico utilizando o índice de temperatura e umidade, para bovinocultura de leite na Região Sudeste do Brasil; Publicações geradas pelo Núcleo Temático; Núcleo Temático Qualidade do Leite e Segurança Alimentar -Projetos: Diagnóstico e gestão da qualidade na produção de leite; Patogenia, imunologia e controle de Babesia bovis, Babesia bigemina, Anaplasma marginale e seus vetores; Publicações geradas pelo Núcleo Temático; Núcleo Temático Sócio-economia do Agronegócio do Leite Projetos: Análise da dinâmica do setor leiteiro; Estudo econômico da tecnologia de pastejo rotativo na produção de leite; Publicações geradas pelo Núcleo Temático; Subprojetos em fase inicial de execução; Transferência de tecnologia -Comunicação empresarial Negócios Tecnológicos Informaçãor Projeto: Ações para transferência de conhecimento e tecnologia na Embrapa Gado de Leite; Perfil da Embrapa Gado de Leite; Infra-estrutura; Recursos humanos; Acordos e convênios de cooperação técnica e financeira.bitstream/item/81938/1/Relatorio-tecnico-Embrapa-gado-de-leite.pd
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