New further integrability cases for the Riccati equation

postprin

Rotational perturbations in Neveu-Schwarz–Neveu-Schwarz string cosmology

First order rotational perturbations of the flat Friedmann-Robertson-Walker metric are considered in the framework of four dimensional Neveu-Schwarz–Neveu-Schwarz string cosmological models coupled with dilaton and axion fields. For the H field we use the solitonic ansatz, assuming that it is a function of time only. The decay rate of rotation depends mainly upon the dilaton field potential U. The equation for rotation imposes strong limitations upon the functional form of U, restricting the allowed potentials to two: the trivial case U=0 and a generalized exponential type potential. In these two models the metric rotation function can be obtained in an exact analytic form in both Einstein and string frames. In the potential-free case the decay of rotational perturbations is governed by an arbitrary function of time while in the presence of a potential the rotation tends rapidly to zero in both Einstein and string frames.published_or_final_versio

Quantum birth of the Universe in the varying speed of light cosmologies

In the framework of the varying speed of light theory the Wheeler-DeWitt equation is considered in the minisuperspace approximation. The quantum potential is obtained and the tunneling probability is studied in both Vilenkin and Hartle-Hawking approaches.published_or_final_versio

Breast reconstruction with transverse rectus abdominis musculocutaneous (TRAM) flap in young women with breast cancer

Since its introduction in 1982, the transverse rectus nbdominis musculocutaneous (TRAM) flop has become the standard for autogenous breast reconstruction. However, it has serious potential complications. In this article, the 10 TRAM flaps performed at Princess Margaret Hospital from December 1993 to September 1994 for young women with breast carcinoma were evaluated to assess the safety and complications of this technique. Majority of the patients were satisfied with the cosmetic outcome.published_or_final_versio

Iterative solutions for relativistic dissipative cosmologies

Iterative solutions of the gravitational field equations for a homogeneous flat Friedmann-Robertson-Walker Universe filled with a causal bulk viscous fluid in the framework of the full Israel-Stewart-Hiscock theory are presented. The general solution of the field equations are presented in a parametric form in the zeroth-, first-, second-, and mth-order approximation by the method of iteration. The time evolution of the scale factor, energy density, deceleration parameter, entropy, Kretschmann scalar, and bulk viscous pressure-thermodynamic pressure ratio for a Zeldovich fluid-filled space-time are discussed.published_or_final_versio

School health partnership in service learning : a Hong Kong experience

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Assessment of fall-related self-efficacy and activity avoidance in people with Parkinson's disease

<p>Abstract</p> <p>Background</p> <p>Fear of falling (FOF) is common in Parkinson's disease (PD), and it is considered a vital aspect of comprehensive balance assessment in PD. FOF can be conceptualized differently. The Falls-Efficacy Scale (FES) assesses fall-related self-efficacy, whereas the Survey of Activities and Fear of Falling in the Elderly (SAFFE) assesses activity avoidance due to the risk of falling. This study aimed at investigating the validity and reliability of FES and SAFFE in people with PD.</p> <p>Methods</p> <p>Seventy-nine people with PD (mean age; 64 years, SD 7.2) completed the Swedish version of FES(S), SAFFE and the physical functioning (PF) scale of the 36-Item Short-Form Health Survey (SF-36). FES(S) and SAFFE were administered twice, with an 8.8 (SD 2.3) days interval. Assumptions for summing item scores into total scores were examined and score reliability (Cronbach's alpha and test-retest reliability) were calculated. Construct validity was assessed by examining the pattern of Spearman correlations (r_s) between the FES(S)/SAFFE and other variables, and by examining differences in FES(S)/SAFFE scores between fallers and non-fallers, genders, and between those reporting FOF and unsteadiness while turning.</p> <p>Results</p> <p>For both scales, item mean scores (and standard deviations) were roughly similar and corrected item-total correlations exceeded 0.4. Reliabilities were ≥0.87. FES(S)-scores correlated strongest (r_s, -0.74, p < 0.001) with SAFFE-scores, whereas SAFFE-scores correlated strongest with PF-scores (r_s, -0.76, p < 0.001). Both scales correlated weakest with age (r_s≤ 0.08). Experiencing falls, unsteadiness while turning, and FOF was associated with lower fall-related self-efficacy and higher activity avoidance.</p> <p>Conclusions</p> <p>This study provides initial support for the score reliability and validity of the FES(S) and SAFFE in people with PD.</p

α-Synuclein Suppression by Targeted Small Interfering RNA in the Primate Substantia Nigra

The protein α-synuclein is involved in the pathogenesis of Parkinson's disease and other neurodegenerative disorders. Its toxic potential appears to be enhanced by increased protein expression, providing a compelling rationale for therapeutic strategies aimed at reducing neuronal α-synuclein burden. Here, feasibility and safety of α-synuclein suppression were evaluated by treating monkeys with small interfering RNA (siRNA) directed against α-synuclein. The siRNA molecule was chemically modified to prevent degradation by exo- and endonucleases and directly infused into the left substantia nigra. Results compared levels of α-synuclein mRNA and protein in the infused (left) vs. untreated (right) hemisphere and revealed a significant 40–50% suppression of α-synuclein expression. These findings could not be attributable to non-specific effects of siRNA infusion since treatment of a separate set of animals with luciferase-targeting siRNA produced no changes in α-synuclein. Infusion with α-synuclein siRNA, while lowering α-synuclein expression, had no overt adverse consequences. In particular, it did not cause tissue inflammation and did not change (i) the number and phenotype of nigral dopaminergic neurons, and (ii) the concentrations of striatal dopamine and its metabolites. The data represent the first evidence of successful anti-α-synuclein intervention in the primate substantia nigra and support further development of RNA interference-based therapeutics

Labeling of Multiple HIV-1 Proteins with the Biarsenical-Tetracysteine System

Due to its small size and versatility, the biarsenical-tetracysteine system is an attractive way to label viral proteins for live cell imaging. This study describes the genetic labeling of the human immunodeficiency virus type 1 (HIV-1) structural proteins (matrix, capsid and nucleocapsid), enzymes (protease, reverse transcriptase, RNAse H and integrase) and envelope glycoprotein 120 with a tetracysteine tag in the context of a full-length virus. We measure the impact of these modifications on the natural virus infection and, most importantly, present the first infectious HIV-1 construct containing a fluorescently-labeled nucleocapsid protein. Furthermore, due to the high background levels normally associated with the labeling of tetracysteine-tagged proteins we have also optimized a metabolic labeling system that produces infectious virus containing the natural envelope glycoproteins and specifically labeled tetracysteine-tagged proteins that can easily be detected after virus infection of T-lymphocytes. This approach can be adapted to other viral systems for the visualization of the interplay between virus and host cell during infection