6,992 research outputs found
Unification of SU(2)xU(1) Using a Generalized Covariant Derivative and U(3)
A generalization of the Yang-Mills covariant derivative, that uses both
vector and scalar fields and transforms as a 4-vector contracted with Dirac
matrices, is used to simplify and unify the Glashow-Weinberg-Salam model. Since
SU(3) assigns the wrong hypercharge to the Higgs boson, it is necessary to use
a special representation of U(3) to obtain all the correct quantum numbers. A
surplus gauge scalar boson emerges in the process, but it uncouples from all
other particles.Comment: 12 pages, no figures. To be published in Int. J. Mod. Phys.
Pseudogap and the specific heat of high superconductors
The specific heat of a two dimensional repulsive Hubbard model with local
interaction is investigated. We use the two-pole approximation which exhibits
explicitly important correlations that are sources of the pseudogap anomaly.
The interplay between the specific heat and the pseudogap is the main focus of
the present work. Our self consistent numerical results show that above the
occupation , the specific heat starts to decrease due to the
presence of a pseudogap in the density of states. We have also observed a two
peak structure in the specific heat. Such structure is robust with respect to
the Coulomb interaction but it is significantly affected by the occupation
. A detailed study of the two peak structure is carried out in terms of
the renormalized quasi-particle bands. The role of the second nearest neighbor
hopping on the specific heat behavior and on the pseudogap, is extensively
discussed.Comment: 6 pages, 6 figures, accepted for publication in Solid State
Communication
Specific heat of a non-local attractive Hubbard model
The specific heat of an attractive (interaction ) non-local Hubbard
model is investigated. We use a two-pole approximation which leads to a set of
correlation functions. In particular, the correlation function $\
G\delta\delta=1-n_Tn_T=n_{\uparrow}+n_{\downarrow}(0,\pm\pi)(\pm\pi,0)$ eliminates the two peak structure, the low
temperature peak remaining. The effects of the second nearest neighbor hopping
on the specific heat are also investigated.Comment: 5 pages, 7 figure
Teor e rendimento de extrato das folhas de três morfotipos de Arrabidaea chica (Bonpl.) B. Verl. em função de adubação orgânica em Manaus, AM.
A espécie Arrabidaea chica (Bonpl.) B. Verl., também conhecida como crajiru, pariri, chica, cipó-cruz, dentre outros nomes, pertence à famÃlia Bignoniaceae. Este trabalho teve o objetivo de avaliar o teor e rendimento de extrato de crajiru em função de diferentes fontes de adubo orgânico em Manaus, AM. As mudas foram obtidas por estaquia e plantadas em bandejas de poliestireno expandido (72 células) contendo substrato comercial, as quais permaneceram em viveiro durante 60 dias até serem plantadas em campo, no espaçamento de 1,0 m x 1,0 m. O experimento foi conduzido em esquema fatorial 5x3 com delineamento em blocos casualizados onde os nÃveis dos fatores foram as diferentes fontes de adubo orgânico: composto ? 5,0 kg m-2, esterco de aves ? 3,0 kg m-2, casca de guaraná ? 4,0 kg m-2, esterco de gado ? 4,0 kg m-2 e controle (ausência), e os três morfotipos de crajiru. Após 240 dias foram avaliadas a produção de folhas, teor e rendimento de extratos. Os dados foram submetidos à análise de variância e as médias ao Teste de Tukey, a 5% de probabilidade. Observou-se que as fontes de adubo orgânico promoveram melhor produção de folhas para as plantas de A. chica, exceto para o morfotipo 1 que não apresentou diferenças significativas em relação à s fontes utilizadas, sendo que o esterco de aves foi o adubo que proporcionou maior biomassa foliar, teor e rendimento de extratos
Produção de mudas de cajueiro.
Viveiro; Producao de mudas; Postura do enxertador; Doencas e pragas em mudas de cajueiro.bitstream/CNPAT-2010/6605/1/Dc-042.pd
Heterosis in crosses among white grain maize populations with high quality protein.
The objective of this work was to investigate heterosis and its components in 16 white grain maize populations presenting high quality protein. These populations were divided according to grain type in order to establish different heterosis groups. The crosses were carried out according to a partial diallel cross design among flint and dent populations. Seven agronomic traits were evaluated in three environments while four leaf diseases and incidence of corn stunt were evaluated in one. Least square procedure was applied to the normal equation X'Xb = X'Y, to estimate the model effects and their respective sum of squares. Among the heterosis components, in diallel analysis, significance for average heterosis in grain yield, number of days to female flowering and to all evaluated diseases was detected. Specific heterosis was significant for days to female flowering and resistance to Puccinia polysora. Results concerned to grain yield trait indicate that populations with superior performance in dent group, no matter what flint population group is used in crosses, tend to generate superior intervarietal hybrids. In decreasing order of preference, the dent type populations CMS 476, ZQP/B 103 and ZQP/B 101 and the flint type CMS 461, CMS 460, ZQP/B 104 and ZQP/B 102 are recommended to form composites
Lifestyles and surveillance of sexual and reproductive women’s health
Abstract: Background: The epidemic increase of diseases is closely related to lifestyle changes. The low adhesion to breast self-examination and cervical cytology hinders prevention and early diagnosis during the asymptomatic state of two silent diseases, with nonspecific symptoms that are a major cause of death by cancer in the Portuguese female population.
Objectives: To analyze the influence of sociodemographic variables and lifestyles in the surveillance of sexual and reproductive health of Portuguese women.
Methods: Quantitative, non-experimental, correlational and cross-sectional study, conducted with a non-probabilistic convenience sample of 522 women aged between 18 and 67 years old, who applied the questionnaires about Breast self-examination, Knowledge about cervical cancer and the Inventory "My Lifestyle" (Ribeiro, 1993.
Results: The average age of women is 38.89 years old. Women aged 31-37 years old (28.6%), Portuguese (99.1%), cohabiting with a partner and / or child (74.0%), with an active employment status (67 5%), residing in urban areas (55.8%) with higher education and attending family planning consultations have better lifestyles, without statistical significance (F = 0.016, p = 0.899).
Conclusions: Healthy behaviors and lifestyles are crucial to good overall health. Adhesion to surveillance of sexual and reproductive women’s health is influenced by several factors, including the place of residence, employment status and lifestyles. These variables must be considered by health professionals when planning periodic screenings.info:eu-repo/semantics/publishedVersio
Caracterização de sementes de Piper hispidum e Eugenia punicifolia.
O objetivo deste estudo foi verificar a caracterização das sementes de Piper hispidum (Piperaceae) e Eugenia punicifolia (Myrtaceae), espécies de Piperaceae da Coleção de Plantas Medicinais, Aromáticas e Condimentares da Embrapa Amazônia Ocidental (Manaus/AM)
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