129 research outputs found
Empresa social e economia solidária: perspectivas no campo da inserção laboral de portadores de transtorno mental
Remarks upon the mass oscillation formulas
The standard formula for mass oscillations is often based upon the
approximation and the hypotheses that neutrinos have been
produced with a definite momentum or, alternatively, with definite energy
. This represents an inconsistent scenario and gives an unjustified
reduction by a factor of two in the mass oscillation formulas. Such an
ambiguity has been a matter of speculations and mistakes in discussing flavour
oscillations. We present a series of results and show how the problem of the
factor two in the oscillation length is not a consequence of gedanken
experiments, i.e. oscillations in time. The common velocity scenario yields the
maximum simplicity.Comment: 9 pages, AMS-Te
Contemplations on Dirac's equation in quaternionic coordinates
A formulation of Dirac's equation using complex-quaternionic coordinates
appears to yield an enormous gain in formal elegance, as there is no longer any
need to invoke Dirac matrices. This formulation, however, entails several
peculiarities, which we investigate and attempt to interpret
Quaternionic Electroweak Theory
We explicitly develop a quaternionic version of the electroweak theory, based
on the local gauge group . The need of a complex
projection for our Lagrangian and the physical significance of the anomalous
scalar solutions are also discussed.Comment: 12 pages, Revtex, submitted to J. Phys.
Os significados da reforma psiquiátrica para os trabalhadores de saúde mental de Goiânia
Bound State Inequality for High Mass Exchanges in a Scalar Field Model
Ladder diagrams are relevant for the study of bound states. The condition
upon the coupling strength for the existence of a bound state has been deduced
in a scalar field theory for the case of low mass exchanges. We apply this
approach to the case of very high mass exchanges.Comment: 14 pages, 3 figure
Determinants of acquisition and clearance of human papillomavirus infection in previously unexposed young women
Background Global variation in human papillomavirus (HPV) prevalence and persistence may be explained by differences in risk factors, such as sexual activity, oral contraceptive use, and behavioral factors. We evaluated determinants of acquisition and clearance of HPV infection among young women previously unexposed to HPV. Methods Five hundred thirty-four women aged 15 to 25 years who were cytology and HPV DNA negative, and seronegative for anti-HPV-16/18 antibodies, were recruited (July 2000–September 2001) from study centers in Brazil, the United States, and Canada (NCT00689741/NCT00120848). They were followed up for 76 months. Cervical samples were HPV genotyped via polymerase chain reaction. We used multivariable (forward stepwise, P = 0.15) Cox proportional hazards regression to estimate rate ratios (RR) and 95% confidence intervals (CI), separately according to length of follow-up time. Results On short-term follow-up (0–27 months), 257 (48%; 8535.80 person-months; incidence rate = 30.11; 95% CI, 26.64–34.02) incident HPV infections were detected. Marital status, lifetime number of sex partners, history of any sexually transmitted disease, and occasional use of oral contraceptives were strongly associated with acquisition of any HPV. Having 2 or more lifetime sex partners (RR, 2.03; 95% CI, 1.37–3.02) and a history of any sexually transmitted disease (RR, 1.98; 95% CI, 1.19–3.29) were the most important determinants of high-risk HPV (hrHPV) incidence. During the entire follow-up (0–76 months), an increased hrHPV clearance was found among women in North America (RR, 1.38; 95% CI, 1.08–1.78) and black women (RR, 1.64; 95% CI, 1.04–2.60). Greater number of lifetime partners was associated with reduced clearance rates for any HPV (RR, 0.65; 95% CI, 0.43–0.98). Conclusions We identified variation in risk of HPV acquisition and clearance among women unexposed to HPV at baseline
Supersymmetrization of Quaternion Dirac Equation for Generalized Fields of Dyons
The quaternion Dirac equation in presence of generalized electromagnetic
field has been discussed in terms of two gauge potentials of dyons.
Accordingly, the supersymmetry has been established consistently and thereafter
the one, two and component Dirac Spinors of generalized quaternion Dirac
equation of dyons for various energy and spin values are obtained for different
cases in order to understand the duality invariance between the electric and
magnetic constituents of dyons.Comment: Key words: Supersymmetry, quaternion, Dirac equation, dyons PACS No.:
11.30.Pb, 14.80.Ly, 03.65.G
Construindo sentidos e possibilidades: a experiência da equipe de incubação de um empreendimento solidário
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