General CPT-even dimension-five nonminimal couplings between fermions and photons yielding EDM and MDM

In this letter, we examine a new class of CPT-even nonminimal interactions, between fermions and photons, deprived of higher order derivatives, that yields electric dipole moment (EDM) and magnetic dipole moment (MDM) in the context of the Dirac equation. The couplings are dimension-five CPT-even and Lorentz-violating nonminimal structures, composed of a rank-2 tensor, $T_{\mu\nu}$, the electromagnetic tensor, and gamma matrices, being addressed in its axial and non-axial Hermitian versions, and also comprising general possibilities. We then use the electron's anomalous magnetic dipole moment and electron electric dipole moment measurements to reach upper bounds of $1$ part in $10^{20}$ and $10^{25}$ (eV )$^{-1}$

Dimensional reduction of the CPT-even electromagnetic sector of the Standard Model Extension

The CPT-even abelian gauge sector of the Standard Model Extension is represented by the Maxwell term supplemented by $(K_{F})_{\mu\nu\rho\sigma}F^{\mu\nu}F^{\rho\sigma}$, where the Lorentz-violating background tensor, $(K_{F})_{\mu\nu\rho\sigma}$, possesses the symmetries of the Riemann tensor. In the present work, we examine the planar version of this theory, obtained by means of a typical dimensional reduction procedure to $(1+2)$ dimensions. The resulting planar electrodynamics is composed of a gauge sector containing six Lorentz-violating coefficients, a scalar field endowed with a noncanonical kinetic term, and a coupling term that links the scalar and gauge sectors. The dispersion relation is exactly determined, revealing that the six parameters related to the pure electromagnetic sector do not yield birefringence at any order. In this model, the birefringence may appear only as a second order effect associated with the coupling tensor linking the gauge and scalar sectors.The equations of motion are written and solved in the stationary regime. The Lorentz-violating parameters do not alter the asymptotic behavior of the fields but induce an angular dependence not observed in the Maxwell planar theory.Comment: 13 pages, revtex style, no figures, to appear in Physical Review D(2011

Influence of Lorentz-violating terms on a two-level system

The influence of Lorentz- and CPT-violating terms of the extended Standard Model on a semi-classical two-level system is analyzed. It is shown that the Lorentz-violating background (when coupled with the fermion sector in a vector way) is able to induce modifications on the Rabi oscillation pattern, promoting sensitive modulations on the usual oscillations. As for the term involving the coefficient coupled in an axial vector way, it brings about oscillations both on energy states and on the spin states (implied by the background). It is also seen that such backgrounds are able to yield state oscillations even in the absence of the electromagnetic field. The foreseen effects are used to establish upper bounds on the Lorentz-violating coefficients.Comment: 13 pages, 6 figures, revtex style

Learning with the Amerindians: the evaluation of pelvic floor disorders among indigenous women who live in the Xingu Indian Park,Brazil

Objective: to evaluate the pelvic floor muscles and the incidence of pelvic organ prolapse among indigenous women who live in Xingu Indian Park, Mato Grosso, Brazil. 
Methods: observational study with 377 indigenous women, mean age 31+/-15 years, mean gravity 5+/-4, mean parity 4+/-3 and mean body mass index 23,3+/-4 Kg/m2. The Pelvic Organ Prolapse Quantification (POP-Q) was the system used to quantification the staging of pelvic support and the pelvic floor muscle strength was assessed by a perineometer. Logistic regression was used to determine odds ratios and 95% CI for factors that were associated with prolapse. 
Results: The overall distribution of POP-Q stage system was the following: 15,6% stage 0, 19,4% stage I, 63,9% stage II and 0,8% stage III. Parity (OR=9.40, 95% CI 2.81-31,42) and age (OR=1,03, 95% IC 1,01-1,05) were the most important risk factors for pelvic organ prolapse. The high resting pressure was considered as a protecting factor (OR=0,96, 95% IC 0,94-0,98). 
Conclusions: Like non indigenous community, age and the parity were the most important risk factors to the genital prolapse; however the pelvic floor muscles strength were intact, maybe due to the indigenous lifestyle