3,470 research outputs found
Cosmologies with Two-Dimensional Inhomogeneity
We present a new generating algorithm to construct exact non static solutions
of the Einstein field equations with two-dimensional inhomogeneity. Infinite
dimensional families of inhomogeneous solutions with a self interacting
scalar field, or alternatively with perfect fluid, can be constructed using
this algorithm. Some families of solutions and the applications of the
algorithm are discussed.Comment: 9 pages, one postscript figur
Yoga Intervention For Adolescent Females With Juvenile Idiopathic Arthritis
Juvenile idiopathic arthritis (JIA) is a chronic rheumatic disease associated with pain, stiffness and increased psychosocial burden. The purpose of this study was to investigate through an ABAB single-case design the impact of a yoga intervention on pain and morning stiffness in adolescent females with JIA. A secondary aim was to assess the impact of this intervention on self-efficacy, mindfulness, and health-related quality of life (HRQOL). Two adolescents with JIA participated in three yoga groups and daily home yoga practice with a DVD. Participants engaged in daily self-monitoring of pain and stiffness and completed questionnaires assessing psychosocial functioning at pre- and post-intervention. A three-month follow-up on primary and secondary measures was conducted. Primary outcomes were evaluated using visual inspection and the conservative dual criterion (CDC) method. Results suggested that for one participant, there were no overall systematic changes in pain or stiffness as a result of the intervention; however, trends toward changes in pain were present during the final phases of the study. For the second participant, systematic changes were observed across most but not all phases for morning stiffness, whereas results for pain were less consistent. Modest changes were revealed on secondary outcome measures; however, not consistently in the direction of hypotheses. Lack of stable baseline data for both participants was a significant limitation of the study and is discussed. More research is needed to determine if the yoga intervention utilized in this study is an effective method for reducing pain and stiffness and enhancing psychosocial functioning in adolescent girls with JIA
On the Entropy and the Density Matrix of Cosmological Perturbations
We look at the transition to the semiclassical behaviour and the decoherence
process for the inhomogeneous perturbations in the inflationary universe. Two
different decoherence mechanisms appear: one dynamical, accompanied with a
negligible, if at all, entropy gain, and the other, effectively irreversible
dephasing, due to a rapid variation in time of the off-diagonal density matrix
elements in the post-inflationary epoch. We thus settle the discrepancies in
the entropy content of perturbations evaluated by different authors.Comment: LaTeX2e with the epsf packag
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