Method for determining reaction rate of mild steel containers during melting of magnesium-aluminium alloys and effect of aluminium content on directionally solidified microstructures

A magnesium alloy of eutectic composition (33 wt-'%Al) was directionally solidified in mild steel tubes at two growth rates, 32 and 580 mum s(-1,) in a temperature gradient between 10 and 20 K mm(-1). After directional solidification, the composition of each specimen varied dramatically, from 32'%Al in the region that had remained solid to 18%Al (32 mum s(-1) specimen) and 13%Al (580 mum s(-1) specimen) at the plane that had been quenched from the eutectic temperature. As the aluminium content decreased, the microstructure contained an increasing volume fraction of primary magnesium dendrites and the eutectic morphology gradually changed from lamellar to partially divorced. The reduction in aluminium content was caused by the growth of an Al-Fe phase ahead of the Mg-Al growth front. Most of the growth of the Al-Fe phase occurred during the remelting period before directional solidification. The thickness of the Al-Fe phase increased with increased temperature and time of contact with the molten Mg-Al alloy. (C) 2003 Maney Publishing.

The assessment of motivation for behaviour change among sex offenders against children: an investigation of the utility of the Stages of Change Questionnaire

A better understanding of motivation for behaviour change among sex offenders against children would improve treatment programmes designed to modify sexual offending behaviour. However, investigation of this issue is limited by lack of theoretically and empirically sound measures of motivation for behaviour change among sex offenders. This paper reports on two studies that were conducted to investigate the psychometric properties (validity, reliability, and social desirability) of the Stages of Change Questionnaire, adapted to measure motivation for behaviour change among sex offenders against children. In Study 1, the psychometric properties of the questionnaire were assessed for sex offenders against children (n=36) who were on a treatment waiting list. In Study 2, the psychometric properties of the questionnaire were assessed for sex offenders against children (n=47) at pre-treatment, mid-treatment, and post-treatment. Both studies supported the validity and reliability of the adapted Stages of Change Questionnaire, and the influence of social desirability upon responding was less than expected. The results of this investigation supported the potential utility of the Stages of Change Questionnaire as a measure of motivation for behaviour change for sex offenders against children.

Modification of tissue fatty acid composition in Murray cod (Maccullochella peelii peelii, Mitchell) resulting from a shift from vegetable oil diets to a fish oil diet.

The dynamics of fatty acid composition modifications were examined in tissues of Murray cod fed diets containing fish oil (FO), canola oil (CO) and linseed oil (LO) for a 25-week period and subsequently transferred to a FO (finishing/wash-out) diet for a further 16 weeks. At the commencement of the wash-out period, following 25 weeks of vegetable oil substitution diets, the fatty acid compositions of Murray cod fillets were reflective of the respective diets. After transfer to the FO diet, differences decreased in quantity and in numerousness, resulting in a revert to the FO fatty acid composition. Changes in percentages of the fatty acids and total accumulation in the fillet could be described by exponential equations and demonstrated that major modifications occurred in the first days of the finishing period. A dilution model was tested to predict fatty acid composition. In spite of a general reliability of the model (Y=0.9234X+0.4260, R²=0.957, P<0.001, where X is the predicted percentage of fatty acid; Y the observed percentage of fatty acid), in some instances the regression comparing observed and predicted values was markedly different from the line of equity, indicating that the rate of change was higher than predicted (i.e. Y=0.4205X+1.191, R²=0.974, P<0.001, where X is the predicted percentage of α-linolenic acid; Y the observed percentage of α-linolenic acid). Ultimately, using the coefficient of distance (D), it was shown that the fatty acid composition of fish previously fed the vegetable oil diets returned to the average variability of the fillet fatty acid composition of Murray cod after 70 or 97 days (LO and CO respectively).

Individual, social and home environment determinants of change in children's television viewing: the Switch-Play intervention

Understanding potential determinants of change in television (TV) viewing among children may enhance the effectiveness of programs targeting this behaviour. This study aimed to investigate the contribution of individual, social and home environment factors among 10-year-old Australian children to change in TV viewing over a 21-month period. A total of 164 children (49% boys) completed a 19-lesson (9-month) intervention program to reduce TV viewing time. Children completed self-administered surveys four times over 21 months (pre- and post-intervention, 6- and 12-month follow-up). Baseline factors associated with change in TV viewing during the intervention and follow-up periods were: ‘asking parents ≥once/week to switch off the TV and play with them’ (21.6 min/day more than those reporting <once/week, p = 0.007); being able to ‘watch just 1 h of TV per day’ (26.1 min/day less than those who could not, p = 0.010); ‘watching TV no matter what was on’ (36.6 min/day more than those who did not, p < 0.001); and ‘continuing to watch TV after their program was over’ (33.0 min/day more than those who did not, p = 0.006). With every unit increase in baseline frequency of TV viewing with family and friends, children spent on average 4.0 min/day more watching TV over the 21-month period (p = 0.047). Baseline number and placement of TVs at home did not predict change in children's TV viewing over the 21 months. Greater understanding of the family dynamics and circumstances, as well as the individual and social determinants of TV viewing, will be required if we are to develop effective strategies for reducing TV viewing in children.

Reliability of moderate-intensity and vigorous physical activity stage of change measures for young adults.

Background
The purpose of this study was to examine the reliability of stage of change (SOC) measures for moderate-intensity and vigorous physical activity in two separate samples of young adults. Staging measures have focused on vigorous exercise, but current public health guidelines emphasize moderate-intensity activity.
Method
For college students in the USA (n = 105) and in Australia (n = 123), SOC was assessed separately on two occasions for moderate-intensity activity and for vigorous activity. Test–retest repeatability was determined, using Cohen’s kappa coefficient.
Results
In both samples, the reliability scores for the moderate-intensity physical activity staging measure were lower than the scores for the vigorous exercise staging measure. Weighted kappa values for the moderate-intensity staging measure were in the “fair to good” range for both studies (0.50 and 0.45); for the vigorous staging measure kappa values were “excellent” and “fair to good” (0.76 and 0.72).
Conclusions
There is a need to standardize and improve methods for staging moderate-intensity activity, given that such measures are used in public health interventions targeting HEPA (health-enhancing physical activity).

Scallop size does not predict amount or rate of induced sperm release

Within populations of broadcast spawning marine invertebrates such as scallops, larger animals typically have larger gonads. Presumably, this means those larger males have more sperm to release than small males. However, there has never been a direct test of whether larger males actually release more sperm, at a higher rate, during spawning. To address this, we compared the allometry of induced sperm release with that of reproductive investment (gonad weight) in ripe males of 2 species of scallops, Chlamys bifrons and Chlamys asperrima. We did not find that larger scallops released more sperm or released it faster than small scallops, and were able to reject the hypothesis that instantaneous sperm release was related to body size in the same way as gonad weight. Consequently, we speculate that if larger broadcast spawning males do release more sperm, they may do so by spawning on more occasions within a reproductive season.

The impact of change on employees : what do annual reports say?

As part of the accountability process public companies are required to report annually to stakeholders. Given the substantial investment in human capital, the disclosure of employment related policies, and the impact of changing policies and practices on employees, could be expected. Over the last few decades the UK banking sector has experienced major change. Increased competition, technology, regulation and deregulation have all contributed to changing practices, which have had a significant impact on employees. This paper examines changes in the banking sector, and the employee information reported in the annual reports of a large UK bank, over the period 1980 to 1995. The purpose of this paper is to examine how the changes, and the effects of the changes on employees, were reported in the annual reports.

Rethinking causality: pattern as the science of change

In this book, Linda Glassop describes an integrative framework referred to as the SOP model of change. The SOP model is derived from the notion that structures (S) are organised (O) by processes (P). The concept of SOP is relevant to any real thing, at any level of analysis

Community reintegration of ex-prisoners : type and degree of change in variables influencing successful reintegration

Community reintegration of ex-prisoners is an important issue in efforts to reduce recidivism. The present study examined the multiple, complex, and dynamic nature of variables influencing successful reintegration by assessing the type and degree of change in reintegration variables over time. Participants were 79 adult prisoners (54 male, 25 female) who completed a prerelease questionnaire 1 month before their release, which focused on prison-related variables, participant background, and anticipated conditions upon release. A postrelease questionnaire was administered to the same participants at 1-4 weeks and 3-4 months postrelease, focusing on the quality of life conditions experienced following release. Results indicate that current health ratings and several indicators of drug use were significantly different over the three measurement phases. Ratings of employment and housing stability, finance, and social support were unchanged over the postrelease period. Theoretical implications of the present investigation for reintegration theory are discussed, together with practical applications.

Prospective study of change in patellar tendon abnormality on imaging and pain over volleyball season

Objective: Patellar tendon injury, defined by tendon abnormality (TA) on imaging and by pain, is common among volleyball players, but little is known about change in this injury over a volleyball season. Increased activity in the season compared with the off season may result in the development of TA and/or pain. This study investigated the behaviour of TA and pain over a competitive volleyball season.

Methods: Tendon abnormality and pain were measured in 101 volleyball players at the beginning and end of a season. Pain was measured with the single leg decline squat test, which loads the patellar tendon, and TA was detected with ultrasound imaging. Hours of weekly activity were measured and compared during the season and the off season. The proportion of tendons that underwent development and resolution in TA and/or pain over the season was investigated.

Results: Hours of weekly activity was greater during the season than in the off season. Most of the tendons investigated (66.3%) did not undergo a change in TA or pain over the season. Tendon abnormality and/or pain developed in 16.6% of tendons and resolved in 11.2%.

Conclusions: The tendons of volleyball players respond variably to the increased load over the season. Change in TA and pain does not appear to be entirely dependent upon load.

Handbook of teacher education : globalization, standards and professionalism in times of change

This book provides an international review of the current state of teacher education, with chapters from an international group of teacher educators. It focuses on major issues that are confronting teacher educators now and in the next decade. These include the impact of globalization on the profession of teaching, and how teacher education must deal with changing accountability requirements from governments and establish a set of minimum standards acceptable to enable a person to teach. The work also considers aspects of the three major phases of teacher education: the period prior to commencing in the profession, successful induction into the profession, and the ongoing professional development of teachers. Finally, it identifies ways in which new technologies can be used to improve the training and ongoing development of teachers. Cases from different countries are used to provide a rich base of data to help us understand how the profession is moving onwards.