Gauged motion in general relativity and in Kaluza-Klein theories

In a recent paper [1] a new generalization of the Killing motion, the {\it gauged motion}, has been introduced for stationary spacetimes where it was shown that the physical symmetries of such spacetimes are well described through this new symmetry. In this article after a more detailed study in the stationary case we present the definition of gauged motion for general spacetimes. The definition is based on the gauged Lie derivative induced by a threading family of observers and the relevant reparametrization invariance. We also extend the gauged motion to the case of Kaluza-Klein theories.Comment: 42 pages, revised version, typos correction along with some minor changes, Revtex forma

Impact of acceptance and commitment-based psychoeducation on the adjustment of expressed emotion in families of patients with bipolar disorder

Background: Expressed emotion is one of the key factors resulting in relapse of psychiatric disorders. Expressed emotion is a critical, hostile and emotionally over-involved attitude that relatives have toward a family member with such disorder. Since stress from the expressed emotion leads to relapse in person with a disorder, the present study aimed to investigate the effect of mental training based on the acceptance and commitment on the regulation of expressed emotion in families of patients with bipolar disorder. Materials and Methods: This quasi-experimental study was carried out on families of patients with bipolar disorder referring to Kargarnejad hospital (Kashan, Iran). The purposive sampling method was used to select the participants. As an intervention acceptance and commitment-based psychoeducation of the families was held in 10 sessions. Expressed emotion questionnaire was completed by relatives pre- and post-intervention. Results: The results showed that the level of expressed emotion reduced after the intervention in families of patients with bipolar disorder (P<0.001). A significant reduction was observed in the level of expressed emotion in all four subscales (negative attitudes, tolerance/expectations, harassment and intervention and emotional response) (P<0.001). Conclusion: Family psychoeducation based on the acceptance and commitment can be effective in the regulation of expressed emotion in families of patients suffering from bipolar disorder

Ecological sensitivity of the Persian Gulf coastal region (Case study: Bushehr province)

Coastal area sensitivity evaluation is in fact, the evaluation of an extraordinary ecological rich region. This study has been based on established criteria and values. The aim of this sensitivity evaluation has been to give objectivity to the Bushehr Province coastline region, so as to be able to pinpoint areas requiring ecological protection. With this objective, initially, the boundaries of the area under evaluation were first established, based on the findings of the Integrated Coastal Zone Management plan (ICZM). Then, based on these parameters and bygeo-referencing photo mosaic Land Sat Satellite images (2003) and IRS’ (2004) were taken and basic maps of two influential areas were evaluated within the above mentioned limits which included the coastal village boundaries. The coastal line of the area being evaluated (set back line) was 673.62 kms comprising an area of 384,810hectares. In this research the blueprint of a linear mathematical model was planned according to the Analytic Hierarchy Process method backed by the Arc-GIS Software program. In this model the value of influencing sensitivity factors were not applied in the same manner but by determining weight coefficients, the value and importance of each factor was determined according to the amount of sensitivity inflicted on the specified environment. In total, in the area under consideration, about 30 percent were defined as very high sensitivity areas

Stability for Rayleigh-Benard convective solutions of the Boltzmann equation

We consider the Boltzmann equation for a gas in a horizontal slab, subject to a gravitational force. The boundary conditions are of diffusive type, specifying the wall temperatures, so that the top temperature is lower than the bottom one (Benard setup). We consider a 2-dimensional convective stationary solution, which is close for small Knudsen number to the convective stationary solution of the Oberbeck-Boussinesq equations, near above the bifurcation point, and prove its stability under 2-d small perturbations, for Rayleigh number above and close to the bifurcation point and for small Knudsen number

Quantum gravitational optics: Effective Raychaudhuri equation

Vacuum polarization in QED in a background gravitational field induces interactions which {\it effectively} modify the classical picture of light rays, as the null geodesics of spacetime. These interactions violate the strong equivalence principle and affect the propagation of light leading to superluminal photon velocities. Taking into account the QED vacuum polarization, we study the propagation of a bundle of rays in a background gravitational field. To do so we consider the perturbative deformation of Raychaudhuri equation through the influence of vacuum polarization on photon propagation. We analyze the contribution of the above interactions to the optical scalars namely, shear, vorticity and expansion using the Newman-Penrose formalism.Comment: 17 pages, 1 figure, RevTex format, Replaced with the published versio

Exponential stability of the solutions of the Boltzmann equation for the Benard problem

International audienceWe complete the result in the former paper 'Stability for Rayleigh-benard convective solutions of the Boltzmann equation' by showing the exponential decay of the perturbation of the laminar solution below the critical Rayleigh number and of the convective solutions above the critical Rayleigh number, in the kinetic framework

Attenuation of serum laminin concentrations upon treatment of chronic hepatitis

Objectives: The aim of this work was to determine the serum laminin level cutoff point for predicting liver fibrosis highlighting its diagnostic value and determining the effect of treatment on serum laminin concentrations. Methods: Serum laminin concentrations in chronic hepatitis patients (n=62) and controls (n=20) were compared by ELISA and stages of fibrosis were assessed according to the modified Knodell score system. Results: Mean serum laminin concentration in patients (91.9 ± 20.9 ng/ml) was greater than controls (46.2 ± 10.2 ng/ml; p <0.001). Serum concentrations of laminin in all stages of hepatic fibrosis were significantly higher than those of healthy controls (p <0.05). A cutoff point of 52ng laminin/ml of serum was obtained for the discrimination of various stages of liver fibrosis showing a good sensitivity (96.8%) and specificity (80%). After 6 months of treatment, a gradual decrease in serum laminin concentrations were observed, however the level was still higher than that of the healthy group (p<0.05). Conclusions: Our findings suggest that the serum laminin concentration is a useful noninvasive marker of liver fibrosis and shows a strong positive correlation with different stages of the disease