Atomic scale interface engineering for strain compensated epitaxially grown InAs/AlSb superlattices.

This paper presents a systematic investigation of strain compensation schemes for InAs/AlSb superlattices (SLs) on GaSb substrates. Short growth interruptions (soak times) under varying arsenic and/or antimony beam equivalent pressures in InAs/AlSb SLs with exemplary dimensions of about ((2.4/2.4) ± 0.2) nm were investigated to achieve strain compensation. When using uncracked As(4), strain compensation was found to be unaccomplishable unless sub-monolayer AlAs spikes were inserted at the InAs → AlSb interface. In contrast, the supply of cracked As(2) dimers leads directly to the formation of strain compensating AlAs-like interfaces. This mechanism allows various growth sequences for strain compensated superlattices, including soak-time-free and Sb-soak-only SL growth. Each of the two latter approaches yields layers with excellent crystal quality and minimal intermixing at the heterointerfaces as verified by high resolution x-ray diffraction analysis and transmission electron microscopy.

Towards a learning organization: the introduction of a client-centered team-based organization in administrative surveying work.

Within administrative surveying work in Sweden, a transition to a client-centered team-based organization was made during 1998. The aim of this study was to describe the employees' perceptions and expectations of job and organizational practices when working as a generalist in a client-centered team-based organization; job and organizational practices and well-being and effectiveness measures were examined when introducing a team-based organization. Interventions such as courses in how to cope with the role of a generalist, how to increase service to clients, education in technology, law and economics, as well as computer information support, were ongoing at the time of the study. The Team Work Profile and QPS Nordic questionnaires were used. All the surveyors in five regions in Sweden participated, in total 640 surveyors. The transition to a client-centered team-based organization was expected to improve job control and job content but at the same time lead to impairments in job climate and group cohesion. Distress was associated with negative future expectations of the organization. High job control and group cohesion were the central contributors towards growth in personal competence and social effectiveness of teamwork. Both internal and external client-related activities of team and organization were in focus during the transition.

Sick but yet at work. An empirical study of sickness presenteeism.

STUDY OBJECTIVE: The study is an empirical investigation of sickness presenteeism in relation to occupation, irreplaceability, ill health, sickness absenteeism, personal income, and slimmed down organisation. DESIGN: Cross sectional design. SETTING: Swedish workforce. PARTICIPANTS: The study group comprised a stratified subsample of 3801 employed persons working at the time of the survey, interviewed by telephone in conjunction with Statistics Sweden's labour market surveys of August and September 1997. The response rate was 87 per cent. MAIN RESULTS: A third of the persons in the total material reported that they had gone to work two or more times during the preceding year despite the feeling that, in the light of their perceived state of health, they should have taken sick leave. The highest presenteeism is largely to be found in the care and welfare and education sectors (nursing and midwifery professionals, registered nurses, nursing home aides, compulsory school teachers and preschool/primary educationalists. All these groups work in sectors that have faced personnel cutbacks during the 1990s). The risk ratio (odds ratio (OR)) for sickness presenteeism in the group that has to re-do work remaining after a period of absence through sickness is 2.29 (95% CI 1.79, 2.93). High proportions of persons with upper back/neck pain and fatigue/slightly depressed are among those with high presenteeism (p< 0.001). Occupational groups with high sickness presenteeism show high sickness absenteeism (rho = 0. 38; p<.01) and the hypothesis on level of pay and sickness presenteeism is also supported (rho = -0.22; p<0.01). CONCLUSIONS: Members of occupational groups whose everyday tasks are to provide care or welfare services, or teach or instruct, have a substantially increased risk of being at work when sick. The link between difficulties in replacement or finding a stand in and sickness presenteeism is confirmed by study results. The categories with high sickness presenteeism experience symptoms more often than those without presenteeism. The most common combination is low monthly income, high sickness absenteeism and high sickness presenteeism.

Facial EMG responses to noise.

Tension of the forehead increases as a response to unpleasant stimuli. In three experiments EMG activity in corrugator muscle was measured to test this response as an indicator of noise annoyance. In Exp. 1 (n = 24) monotonic sound level-response functions were obtained for four levels of 100- and 1000-Hz tones. In Exp. 2 (n = 20) recordings were made during work with a simple and a difficult task in a group of women and a group of men. Larger responses were obtained during the difficult task, especially during noise exposure. The response was much larger for the women. Exp. 3 (n = 24) showed that the sex difference was unaffected by a correction for differences in maximum level of corrugator response. Rated annoyance was a linear function of log EMG.

A three-year follow-up of 195 reported occupational over-exertion injuries.

Three years after reporting occupational over-exertion injuries, 181 persons took part in a follow-up study by questionnaire. The objective was to study these persons with respect to their current status of health, well-being and functional capacity and when possible compare collected data to reference data from the "normal population". The studied group reported more physical and psychological symptoms than the reference groups. More than 50% reported difficulties in activities of daily living. Long sick-leaves in the year following the reported injury were associated with remaining pain and low rate of employment. Three years after the injury, 109 persons were in employment. Almost one third of these had changed occupations and now had more varied tasks than at the time of the report. Those whose work loads had been reduced after the injury, did not report less musculoskeletal disorders than others. However, access to social support was positively related with health and psychological well-being.