11,653 research outputs found
Localization properties of a tight-binding electronic model on the Apollonian network
An investigation on the properties of electronic states of a tight-binding
Hamiltonian on the Apollonian network is presented. This structure, which is
defined based on the Apollonian packing problem, has been explored both as a
complex network, and as a substrate, on the top of which physical models can
defined. The Schrodinger equation of the model, which includes only nearest
neighbor interactions, is written in a matrix formulation. In the uniform case,
the resulting Hamiltonian is proportional to the adjacency matrix of the
Apollonian network. The characterization of the electronic eigenstates is based
on the properties of the spectrum, which is characterized by a very large
degeneracy. The rotation symmetry of the network and large number of
equivalent sites are reflected in all eigenstates, which are classified
according to their parity. Extended and localized states are identified by
evaluating the participation rate. Results for other two non-uniform models on
the Apollonian network are also presented. In one case, interaction is
considered to be dependent of the node degree, while in the other one, random
on-site energies are considered.Comment: 7pages, 7 figure
Modelos de predição para peso e rendimento de cortes cárneos através de medidas no animal vivo.
Os objetivos deste trabalho foram desenvolver equações de predição com a finalidade de estimar o peso e o rendimento de cortes do traseiro de novilhos Braford através de medidas por ultrassom ?in vivo? e avaliar a inclusão das medidas de espessura de gordura na garupa e de profundidade do músculo gluteus medius e as suas relações com a acurácia dos modelos de regressão. Foram utilizados 100 novilhos com peso vivo médio de 472 Kg e 24 meses de idade. Nas 48 horas pré abate foram coletadas medidas de ultrassom da área do músculo longissimus (AOLUS); espessura de gordura subcutânea (EGSUS) no sÃtio anatômico entre a 12ª e 13ª costelas; espessura de gordura na garupa (EGP8US) e a profundidade do músculo Gluteus medius (PP8US). As equações para peso de cortes do traseiro (PCT) e para rendimento de cortes do traseiro (RCT) foram desenvolvidas através do procedimento estatÃstico de seleção de variáveis Stepwise. As caracterÃsticas AOLUS, EGSUS, EGP8US e PP8US apresentaram médias de 67,13 cm2; 3,43 mm; 6,14 mm e 86,91 mm respectivamente. Os coeficientes de correlação de Pearson entre as medidas obtidas por ultrassom e na carcaça para AUOLUS e AOLC foram de 0,89, para EGSU e EGSC de 0,92. O R2 para PCT foi de 0,71 e para RCT de 0,31 respectivamente. As variáveis EGP8US e PP8US explicam 11% da variação do rendimento dos cortes do traseiro e devem ser incorporadas no modelo
Metodologia para estimação do mérito genético de animais com paternidade incerta sob inferência bayesiana.
Modelo animal reduzido com efeito materno; Modelo hierárquico bayesiano para paternidade incerta; Validação por simulação; Análise de dados de desempenho de um rebanho Hereford; Inferência Bayesiana; Análises do estudo de simulação; Análises de dados do rebanho Hereford; Critérios para escolha do melhor modelo; Inferência sobre dados simulados; Inferência nos dados do rebanho Hereford; Ganho de peso pós-desmama; Peso à desmama.bitstream/item/55802/1/BP32.pd
Effective action for the field equations of charged black holes
In this article, we consistently reduce the equations of motion for the
bosonic N = 2 supergravity action, using a multi-centered black hole ansatz for
the metric. This reduction is done in a general, non-supersymmetric setup, in
which we extend concepts of BPS black hole technology. First of all we obtain a
more general form of the black hole potential, as part of an effective action
for both the scalars and the vectors in the supergravity theory. Furthermore,
we show that there are extra constraints specifying the solution, which we
calculate explicitly. In the literature, these constraints have already been
studied in the one-center case. We also show that the effective action we
obtain for non-static metrics, can be linked to the "entropy function" for the
spherically symmetric case, as defined by Sen and Cardoso et al.Comment: 18 pages, (v2: small corrections, version to be published in CQG
Truncated states obtained by iteration
Quantum states of the electromagnetic field are of considerable importance,
finding potential application in various areas of physics, as diverse as solid
state physics, quantum communication and cosmology. In this paper we introduce
the concept of truncated states obtained via iterative processes (TSI) and
study its statistical features, making an analogy with dynamical systems theory
(DST). As a specific example, we have studied TSI for the doubling and the
logistic functions, which are standard functions in studying chaos. TSI for
both the doubling and logistic functions exhibit certain similar patterns when
their statistical features are compared from the point of view of DST. A
general method to engineer TSI in the running-wave domain is employed, which
includes the errors due to the nonidealities of detectors and photocounts.Comment: 10 pages, 22 figure
First-order flow equations for extremal black holes in very special geometry
We construct interpolating solutions describing single-center static extremal
non-supersymmetric black holes in four-dimensional N=2 supergravity theories
with cubic prepotentials. To this end, we derive and solve first-order flow
equations for rotating electrically charged extremal black holes in a Taub-NUT
geometry in five dimensions. We then use the connection between five- and
four-dimensional extremal black holes to obtain four-dimensional flow equations
and we give the corresponding solutions.Comment: 21 pages. v2: Summary section adde
The pinewood nematode, Bursaphelenchus xylophilus, in Madeira Island
The environmental conditions in Madeira Island are favorable
for the presence and dissemination of the pinewood
nematode (PWN), Bursaphelenchus xylophilus. Five hundred
Pinus pinaster wood samples were collected in several
forest areas and PWN was detected in 22.8 % of the
samples. Bursaphelenchus xylophilus isolates from Madeira
Island displayed the species-specific diagnostic characters.
A morphological variation in the female tail terminus was
detected. In most females, the tail presented a broadly
rounded terminus and, occasionally, a digitate terminus with
a terminal nipple-like extension resembling a mucro. PCR
ITS-RFLP analysis revealed that Madeira Island isolates
exhibited patterns specific to the species B. xylophilus and
similar to virulent isolates. Amplified ITS regions were
further sequenced and no genetic diversity was found for
this genomic region among 17 Portuguese isolates (Madeira
Island and Continental Portugal). Phylogenetic analysis
revealed that Portuguese isolates grouped with isolates from
China, Korea and one isolate from Japa
production of a synthetic recombinant antigen for immunodetection of Pneumocystis jirovecii
Diagnosis of Pneumocystis pneumonia (PcP) relies on the detection of P. jirovecii in respiratory specimens obtained by invasive techniques. Thus, the development of a serological test is urgently needed as it will allow the diagnosis of PcP using blood, an inexpensive and non-invasive specimen. This study aims to combine the production of a multi-epitope synthetic recombinant antigen (RSA) and an ELISA test for detection of anti-P. jirovecii antibodies, in order to develop a new approach for PcP diagnosis. The RSA was selected and designed based on the study of the immunogenicity of the carboxyl-terminal domain of the major surface glycoprotein. This antigen was purified and used as an antigenic tool in an ELISA technique for detection of Ig, IgG and IgM antibodies anti-P. jirovecii (patent-pending no. PT109078). Serum specimens from 88 patients previously categorized in distinct clinical subgroups and 17 blood donors, were analysed. The IgM anti-P. jirovecii levels were statistically increased in patients with PcP (p = 0.001) and the ELISA IgM anti-P. jirovecii test presented a sensitivity of 100% and a specificity of 80.8%, when associated with the clinical diagnosis criteria. This innovative approach, provides good insights about what can be done in the future serum testing for PcP diagnosis.publishersversionpublishe
SÃndrome da Doença Hepática Crónica Agudizada - Resultados ClÃnicos de uma Unidade de Terapia Intensiva em Centro de Transplante Hepático
Objective: To characterize a cohort of acute-on-chronic liver failure patients in Intensive Care and to analyze the all-cause 28-day mortality risk factors assessed at ICU admission and day 3.
Methods: This was a retrospective cohort study of consecutive patients admitted to the intensive care unit between March 2013 and December 2016.
Results: Seventy-one patients were included. The median age was 59 (51 - 64) years, and 81.7% of patients were male. Alcohol consumption alone (53.5%) was the most frequent etiology of cirrhosis and infection (53.5%) was the most common acute-on-chronic liver failure precipitating event. At intensive care unit admission, the clinical severity scores were APACHE II 21 (16 - 23), CLIF-SOFA 13 (11 - 15), Child-Pugh 12 (10 - 13) and MELD 27 (20 - 32). The acute-on-chronic liver failure scores were no-acute-on-chronic liver failure: 11.3%; one: 14.1%; two: 28.2% and three: 46.5%; and the number of organ failures was one: 4.2%; two: 42.3%; three: 32.4%; four: 16.9%; and five: 4.2%. Liver transplantation was performed in 15.5% of patients. The twenty-eight-day mortality rate was 56.3%, and the in-ICU mortality rate was 49.3%. Organ failure at intensive care unit admission (p = 0.02; OR 2.1; 95%CI 1.2 - 3.9), lactate concentration on day 3 (p = 0.02; OR 6.3; 95%CI 1.4 - 28.6) and the international normalized ratio on day 3 (p = 0.03; OR 10.2; 95%CI 1.3 - 82.8) were independent risk factors.
Conclusion: Acute-on-chronic liver failure patients presented with high clinical severity and mortality rates. The number of organ failures at intensive care unit admission and the lactate and international normalized ratio on day 3 were independent risk factors for 28-day mortality. We consider intensive care essential for acute-on-chronic liver failure patients and timely liver transplant was vital for selected patients.info:eu-repo/semantics/publishedVersio
Rede de Multiplicação e Transferência de Materiais Propagativos de Mandioca com qualidade genética e fitossanitária para o estado da Bahia (RENIVA) - avanços e desafios: relato de experiência.
A cultura da mandioca (Manihot esculenta Crantz) possui grande expressão socioeconômica, sobretudo por ser alimento básico para quase um bilhão de pessoas em todo o mundo. A planta é cultivada em dois milhões de hectares, disseminados por todo o Brasil, que mantém a segunda posição no ranking de maior produtor mundial, embora com baixÃssima produtividade. A cultura se destaca na região Nordeste do paÃs, por sua tolerância à seca, constituindo-se numa das poucas alternativas para a sustentabilidade de populações mais carentes. Existem três grandes entraves no sistema de cultivo da mandioca. Um deles diz respeito à baixa disponibilidade de manivas semente de boa qualidade genética e fitossanitária para o plantio, devido principalmente à baixa taxa de multiplicação inerente à planta e inexistência de materiais propagativos comprovadamente livres de patógenos. O outro entrave é a baixa produtividade da cultura, pelo uso de variedades pouco produtivas, mas também fortemente influenciada pela ocorrência de fitopatógenos, alguns dos quais transmitidos pelo material propagativo. É significativa a utilização, para plantio, de material portador de doenças uma vez que os sintomas de muitas delas nem sempre são identificados foco em seleção de material livre de doenças. É o caso do vÃrus do mosaico comum da mandioca e do vÃrus do mosaico das nervuras da mandioca, para os quais é necessário proceder a análises em laboratório para confirmar ou descartar sua presença nas plantas, uma vez que estas últimas podem não apresentar os sintomas de contaminação. O terceiro entrave, e não menos importante, é o insuficiente nÃvel de adoção das tecnologias geradas. É notável a progressiva perda de qualidade genética e fitossanitária das plantas e do seu material propagativo, pelo baixo conhecimento dos agricultores acerca das boas práticas para selecionar material sadio e vigoroso para o plantio. O quarto entrave diz respeito à organização da cadeia produtiva. Há muito se empreendem, no nÃvel do poder público e também da iniciativa privada, ações isoladas e pontuais de produção e multiplicação de material propagativo de mandioca, com resultados pouco efetivos e pouco persistentes. Isso decorre da falta de integração de esforços institucionais que sejam voltados a dar continuidade e longevidade à s rotinas estabelecidas. Em poucos ciclos, os ganhos com sanidade e genética são perdidos, pela progressiva recontaminação do material propagativo e pela ausência de rigor na seleção das plantas mais aptas e produtivas. Este trabalho tem o objetivo de relatar a experiência da Embrapa Mandioca e Fruticultura e de parceiros no estabelecimento de uma rede de produção de material propagativo de mandioca de qualidade genética e fitossanitária adequadas
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