The influence of strontium on porosity formation in Al-Si alloys

Strontium modification is known to alter the amount, characteristics, and distribution of porosity in Al-Si castings. Although many theories have been proposed to account for these effects, most can be considered inadequate because of their failure to resolve contradictions and discrepancies in the literature. In an attempt to critically appraise some of these theories, the amount, distribution, and morphology of porosity were examined in sand-cast plates of Sr-free and Sr-containing pure Al, Al-l wt pet Si, and Al-9 wt pet Si alloys. Statistical significance testing was used to verify apparent trends in the porosity data. No apparent differences in the amount, distribution, and morphology of porosity were observed between Sr-free and Sr-containing alloys with no or very small eutectic volume fractions. However, Sr modification significantly changed the amount, distribution, and morphology of porosity in alloys with a significant volume fraction of eutectic. ne addition of Sr reduced porosity in the hot spot region of the casting, and the pores became well dispersed and rounded. This result can be explained by considering the combined effect of the casting design and the differences in the pattern of eutectic solidification between unmodified and Sr-modified alloys.

Predictive genetic test decisions for Huntington's disease: context, appraisal and new moral imperatives

Predictive testing is one of the new genetic technologies which, in conjunction with developing fields such as pharmacogenomics, promises many benefits for preventive and population health. Understanding how individuals appraise and make genetic test decisions is increasingly relevant as the technology expands. Lay understandings of genetic risk and test decision-making, located within holistic life frameworks including family or kin relationships, may vary considerably from clinical representations of these phenomena. The predictive test for Huntington's disease (HD), whilst specific to a single-gene, serious, mature-onset but currently untreatable disorder, is regarded as a model in this context. This paper reports upon a qualitative Australian study which investigated predictive test decision-making by individuals at risk for HD, the contexts of their decisions and the appraisals which underpinned them. In-depth interviews were conducted in Australia with 16 individuals at 50% risk for HD, with variation across testing decisions, gender, age and selected characteristics. Findings suggested predictive testing was regarded as a significant life decision with important implications for self and others, while the right not to know genetic status was staunchly and unanimously defended. Multiple contexts of reference were identified within which test decisions were located, including intra- and inter-personal frameworks, family history and experience of HID, and temporality. Participants used two main criteria in appraising test options: perceived value of, or need for the test information, for self and/or significant others, and degree to which such information could be tolerated and managed, short and long-term, by self and/or others. Selected moral and ethical considerations involved in decision-making are examined, as well as the clinical and socio-political contexts in which predictive testing is located. The paper argues that psychosocial vulnerabilities generated by the availability of testing technologies and exacerbated by policy imperatives towards individual responsibility and self-governance should be addressed at broader societal levels. (C) 2003 Elsevier Science Ltd. All rights reserved.

The role of psychological climate in facilitating employee adjustment during organizational change

The current research tested a theoretical model of employee adjustment during organizational change based on Lazarus and Folkman's (1984) cognitive-phenomenological framework. The model hypothesized that psychological climate variables would act as coping resources and predict improved adjustment during change. Two variations of this model were tested using survey data from two different organizational samples: 779 public hospital employees and 877 public sector employees. Confirmatory factor analyses and structural equation analyses were conducted in order to evaluate the models. Results showed that employees whose perceptions of the organization and environment in which they were working (that is, psychological climate) were more positive, were more likely to appraise change favourably and report better adjustment in terms of higher job satisfaction, psychological well-being, and organizational commitment, and lower absenteeism and turnover intentions.

Assessment of disease progression in motor neuron disease

Motor neuron disease (MND) is characterised by progressive deterioration of the corticospinal tract, brainstem, and anterior horn cells of the spinal cord. There is no pathognomonic test for the diagnosis of MND, and physicians rely on clinical criteria-upper and lower motor neuron signs-for diagnosis. The presentations, clinical phenotypes, and outcomes of MND are diverse and have not been combined into a marker of disease progression. No single algorithm combines the findings of functional assessments and rating scales, such as those that assess quality of life, with biological markers of disease activity and findings from imaging and neurophysiological assessments. Here, we critically appraise developments in each of these areas and discuss the potential of such measures to be included in the future assessment of disease progression in patients with MND.

Attachment insecurity as a filter in the decoding and encoding of nonverbal behavior in close relationships

In this article, I have focused my comments on the possible associations between the cognitions related to different attachment styles, and the impact that those cognitions are likely to have on nonverbal encoding and decoding. I see attachment insecurity as acting as a filter, distorting both encoding and decoding processes. In terms of decoding, an insecure individual may appraise the situation as more threatening than it actually is, may see the attachment figure as more or less available than he or she actually is, and may make an inappropriate decision about the viability or desirability of seeking proximity to the attachment figure. Attachment insecurity is also likely to inhibit the distressed individual from expressing their distress in a way that is understood by the attachment figure and that increases the likelihood that the attachment figure will engage in supportive behavior.

The role of different sources of communication and trust in reducing change-related uncertainties during organisational change

The current paper presents a qualitadve study of the role of different sources of communicadon in reducing change-related uncertaintj' experienced by employees during organisadonal change. The paper examines the role of trust in influencing how employees' appraise informadon from different sources within organisadons. Interviews with 19 employees from a range of organisadons idendfy the different types of change-related uncertaindes experienced during change. In addidon, the different sources of communicadon utilised by employees are idendfied and the role each source plays in reducing the different t}'pes of uncertaint}' invesdgated. From employee responses it is evident that t)'pically supervisors are the best source of change informadon, while communicadon from senior management usually focuses on strategic issues. Employees indicate that communicadon with coworkers operates as a support mechanism providing an avenue to share grievances arising from the change. Finally, trust is idendfied as playing an important role in influencing who employees go to for informadon when experiencing uncertainty'. ImpUcadons for change management research in addidon to pracdcal implicadons are discussed.