Bremsstrahlung from a microscopic model of relativistic heavy ion collisions

We compute bremsstrahlung arising from the acceleration of individual charged baryons and mesons during the time evolution of high-energy Au+Au collisions at the Relativistic Heavy Ion Collider using a microscopic transport model. We elucidate the connection between bremsstrahlung and charge stop- ping by colliding artificial pure proton on pure neutron nuclei. From the inten- sity of low energy bremsstrahlung, the time scale and the degree of stopping could be accurately extracted without measuring any hadronic observables. PACS: 25.75.-q, 13.85.Q

Use of Satisfaction-Satisfaction Matrix (SSM) to evaluate e-government services from the perspective of Japanese citizens and government service providers

This paper addresses the issue of Japanese e-government benefits evaluation and stresses the need to develop a new measurement tool to evaluate e-government services from the perspective of Japanese citizens and government service providers. While research has used SERVQUAL, SERVPERF and Importance-Performance Analysis (IPA) as evaluation tools to measure quality of services, most of these tools are developed to evaluate quality of services from the perspective of citizens or service providers. In this paper, we propose a new evaluation tool, namely Satisfaction-Satisfaction Matrix (SSM), to gauge both the perceptions of citizens and service providers concerning the performance of e-government services. The matrix not only serves as a useful tool to identify satisfaction responses, but also serves as a strategic decision making tool in the allocation of resources for improving e-government services

Reliability and validity of psychosocial and environmental correlates measures of physical activity and screen-based behaviors among Chinese children in Hong Kong

Background : Insufficient participation in physical activity and excessive screen time have been observed among Chinese children. The role of social and environmental factors in shaping physical activity and sedentary behaviors among Chinese children is under-investigated. The purpose of the present study was to assess the reliability and validity of a questionnaire to measure child- and parent-reported psychosocial and environmental correlates of physical activity and screen-based behaviors among Chinese children in Hong Kong. Methods : A total of 303 schoolchildren aged 9-14 years and their parents volunteered to participate in this study and 160 of them completed the questionnaire twice within an interval of 10 days. Intraclass correlation coefficients (ICCs), kappa statistics, and percent agreement were performed to evaluate test-retest reliability of the continuous and categorical variables, respectively. Exploratory factor analyses (EFAs) were conducted to assess convergent validity of the emergent scales. Cronbach\u27s alpha and ICCs were performed to assess internal and test-retest reliability of the emergent scales. Criterion validity was assessed by correlating psychosocial and environmental measures with self-reported physical activity and screen-based behaviors, measured by a validated questionnaire. Results : Reliability statistics for both child- and parent-reported continuous variables showed acceptable consistency for all of the ICC values greater than 0.70. Kappa statistics showed fair to perfect test-retest reliability for the categorical items. Adequate internal consistency and test-retest reliability were observed in most of the emergent scales. Criterion validity assessed by correlating psychosocial and environmental measures with child-reported physical activity found associations with physical activity in the self-efficacy scale (r = 0.25, P &lt; 0.05), the peer support for physical activity scale (r = 0.25, P &lt; 0.05) and home physical activity environmental (r = 0.14, P &lt; 0.05). Children\u27s screen-based behaviors were associated with the family support for physical activity scale (r = -0.22, P &lt; 0.05) and parental role modeling of TV (r = 0.12, P = 0.053). Conclusions : The findings provide psychometric support for using this questionnaire for examining psychosocial and environmental correlates of physical activity and screen-based behaviors among Chinese children in Hong Kong. Further research is needed to develop more robust measures based on the current questionnaire, especially for peer influence on physical activity and parental rules on screen-based behaviors. <br /

Traumatic Brain Injury in the Elderly: Is it as Bad as we Think?

Traumatic brain injury in elderly patients is a neglected global disease burden. The main cause is fall, followed by motor vehicle accidents. This review article summarizes different aspects of geriatric traumatic brain injury, including epidemiology, pathology, and effects of comorbidities and pre-injury medications such as antiplatelets and anticoagulants. Functional outcome with or without surgical intervention, cognitive outcome, and psychiatric complications are discussed. Animal models are also reviewed in attempt to explain the relationship of aging and outcome, together with advances in stem cell research. Though elderly people in general did fare worse after traumatic brain injury, certain “younger elderly” people, aged 65–75 years, could have a comparable outcome to younger adults after minor to moderate head injury

Single cell analysis shows decreasing FoxP3 and TGFβ1 coexpressing CD4+CD25+ regulatory T cells during autoimmune diabetes

Natural CD4+CD25+ regulatory T (CD4+CD25+ T reg) cells play a key role in the immunoregulation of autoimmunity. However, little is known about the interactions between CD4+CD25+ T reg cells and autoreactive T cells. This is due, in part, to the difficulty of using cell surface markers to identify CD4+CD25+ T reg cells accurately. Using a novel real-time PCR assay, mRNA copy number of FoxP3, TGFβ1, and interleukin (IL)-10 was measured in single cells to characterize and quantify CD4+CD25+ T reg cells in the nonobese diabetic (NOD) mouse, a murine model for type 1 diabetes (T1D). The suppressor function of CD4+CD25+CD62Lhi T cells, mediated by TGFβ, declined in an age-dependent manner. This loss of function coincided with a temporal decrease in the percentage of FoxP3 and TGFβ1 coexpressing T cells within pancreatic lymph node and islet infiltrating CD4+CD25+CD62Lhi T cells, and was detected in female NOD mice but not in NOD male mice, or NOR or C57BL/6 female mice. These results demonstrate that the majority of FoxP3-positive CD4+CD25+ T reg cells in NOD mice express TGFβ1 but not IL-10, and that a defect in the maintenance and/or expansion of this pool of immunoregulatory effectors is associated with the progression of T1D

Repeatability of self-report measures of physical activity, sedentary and travel behaviour in Hong Kong adolescents for the iHealt(H) and IPEN- adolescent studies

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SETDB2 Links E2A-PBX1 to Cell-Cycle Dysregulation in Acute Leukemia through CDKN2C Repression

Acute lymphoblastic leukemia (ALL) is associated with significant morbidity and mortality, necessitating further improvements in diagnosis and therapy. Targeted therapies directed against chromatin regulators are emerging as promising approaches in preclinical studies and early clinical trials. Here, we demonstrate an oncogenic role for the protein lysine methyltransferase SETDB2 in leukemia pathogenesis. It is overexpressed in pre-BCR+ ALL and required for their maintenance in vitro and in vivo. SETDB2 expression is maintained as a direct target gene of the chimeric transcription factor E2A-PBX1 in a subset of ALL and suppresses expression of the cell-cycle inhibitor CDKN2C through histone H3K9 tri-methylation, thus establishing an oncogenic pathway subordinate to E2A-PBX1 that silences a major tumor suppressor in ALL. In contrast, SETDB2 was relatively dispensable for normal hematopoietic stem and progenitor cell proliferation. SETDB2 knockdown enhances sensitivity to kinase and chromatin inhibitors, providing a mechanistic rationale for targeting SETDB2 therapeutically in ALL