On the primordial scenario for abundance variations within globular clusters. The isochrone test

Self-enrichment processes occurring in the early stages of a globular cluster lifetime are generally invoked to explain the observed CNONaMgAl abundance anticorrelations within individual Galactic globulars.We have tested, with fully consistent stellar evolution calculations, if theoretical isochrones for stars born with the observed abundance anticorrelations satisfy the observational evidence that objects with different degrees of these anomalies lie on essentially identical sequences in the Color-Magnitude-Diagram (CMD). To this purpose, we have computed for the first time low-mass stellar models and isochrones with an initial metal mixture that includes the extreme values of the observed abundance anticorrelations, and varying initial He mass fractions. Comparisons with 'normal' alpha-enhanced isochrones and suitable Monte Carlo simulations that include photometric errors show that a significant broadening of the CMD sequences occurs only if the helium enhancement is extremely large (in this study, when Y=0.35) in the stars showing anomalous abundances. Stellar luminosity functions up to the Red Giant Branch tip are also very weakly affected, apart from - depending on the He content of the polluting material - the Red Giant Branch bump region. We also study the distribution of stars along the Zero Age Horizontal Branch, and derive general constraints on the relative location of objects with and without abundance anomalies along the observed horizontal branches of globular clusters.Comment: Accepted for publication in Ap

Work factors and psychological distress in nurses' aides: a prospective cohort study

<p>Abstract</p> <p>Background</p> <p>Nurses' aides (assistant nurses), the main providers of practical patient care in many countries, are doing both emotional and heavy physical work, and are exposed to frequent social encounters in their job. There is scarce knowledge, though, of how working conditions are related to psychological distress in this occupational group. The aim of this study was to identify work factors that predict the level of psychological distress in nurses' aides.</p> <p>Methods</p> <p>The sample of this prospective study comprised 5076 Norwegian nurses' aides, not on leave when they completed a mailed questionnaire in 1999. Of these, 4076 (80.3 %) completed a second questionnaire 15 months later. A wide spectrum of physical, psychological, social, and organisational work factors were measured at baseline. Psychological distress (anxiety and depression) was assessed at baseline and follow-up by the SCL-5, a short version of Hopkins Symptom Checklist-25.</p> <p>Results</p> <p>In a linear regression model of the level of psychological distress at follow-up, with baseline level of psychological distress, work factors, and background factors as independent variables, work factors explained 2 % and baseline psychological distress explained 34 % of the variance. Exposures to role conflicts, exposures to threats and violence, working in apartment units for the aged, and changes in the work situation between baseline and follow-up that were reported to result in less support and encouragement were positively associated with the level of psychological distress. Working in psychiatric departments, and changes in the work situation between baseline and follow-up that gave lower work pace were negatively associated with psychological distress.</p> <p>Conclusion</p> <p>The study suggests that work factors explain only a modest part of the psychological distress in nurses' aides. Exposures to role conflicts and threats and violence at work may contribute to psychological distress in nurses' aides. It is important that protective measures against violent patients are implemented, and that occupational health officers offer victims of violence appropriate support or therapy. It is also important that health service organisations focus on reducing role conflicts, and that leaders listen to and consider the views of the staff.</p

Factors influencing students’ intention to use internet for academic purposes

This study aimed to investigate the factors influencing students’ intention to use the Internet for academic purposes amongst 204 final year business students in public universities in Malaysia.This study integrated theory of planned behavior (TPB) and theory of acceptance model (TAM) as the base model toward that purpose.The research model employs the variables from both theories namely attitudes, subjective norms, perceived behavioral control, perceived usefulness, perceived ease of use, intention, and behavior.A multiple regression analysis provides empirical support for the applicability of integration of TPB and TAM in predicting students’ intention to use the Internet for academic purposes.Results of the study show that attitudes, perceived behavioral control, and perceived usefulness are statistically significant in influencing intention to use the Internet for academic purposes.Based on the results, it can be concluded that students’ intention to use the Internet for academic purposes could be predicted from their attitudes, perceived behavioral control, and perceived usefulness at 49% level.In view of the results, several implications and recommendations are discussed

Experiential Learning-Based Discussion vs. Lecture-Based Discussion: A Comparative Analysis in a Classroom Setting

A study was conducted to determine the effectiveness of experiential learning-based discussions vs. lecture-based discussions in enhancing student understanding of communication network concepts. Undergraduate students (n=188) in four sections of an introduction to management course participated in the study. Two sections discussed communication network concepts after a lecture; two sections discussed the material after an experiential learning exercise. Results indicated the experiential learning - discussion approach was more effective in facilitating understanding than the lecture - discussion approach

An Evaluation of the Minitab Package in Teaching Business Statistics Concepts

"Two studies empirically evaluated the effectiveness of computer assisted instruction in facilitating students’ comprehension of the concepts of the Central Limit Theorem and Type I and Type II error. Undergraduate students were assigned to experimental and control groups. The experimental group’s regular class material was supplemented with a computer assisted instructional exercise from the Minitab Package (Ryan, Joiner &amp; Ryan, 1976). The control group did not experience the exercise. Results indicated that an instructional program supplemented with Minitab was as effective as a program utilizing only traditional instructional methods. The potential utility of the Minitab package in business education is discussed. In recent years, the use of computer-assisted instruction (CAI) techniques has proliferated in educational institutions. These techniques have been applied to the teaching of subjects as widely varied as mathematics and foreign languages. Furthermore, they are used at all levels of education, from early elementary to postgraduate training. The fast implementation of the CAI systems, however, has often preceded a critical examination of the utility of the computer packages in promoting learning of the various subjects for which they are used. This is becoming an issue of widespread concern as educational institutions are investing time and money in implementing computer assisted instructional packages that have not been evaluated for their utility in promoting comprehension of subject matter (Williams &amp; McDonald, 1982). Business education, like many other areas of higher education, has been involved in this proliferation of CAI. Many computerassisted instructional packages are touted as helping students to more effectively comprehend business concepts (Milkovich &amp; Mahoney, 1975; Robson, 1975) but few have been systematically and rigorously evaluated in this respect.