Effect of multiple transverse modes in self-mixing sensors based on vertical-cavity surface-emitting lasers

We investigate the effect of coexisting transverse modes on the operation of self-mixing sensors based on vertical-cavity surface-emitting lasers (VCSELs). The effect of multiple transverse modes on the measurement of displacement and distance were examined by simulation and in laboratory experiment. The simulation model shows that the periodic change in the shape and magnitude of the self-mixing signal with modulation current can be properly explained by the different frequency-modulation coefficients of the respective transverse modes in VCSELs. The simulation results are in excellent agreement with measurements performed on single-mode and multimode VCSELs and on self-mixing sensors based on these VCSELs.

Interactive health communication in preventive medicine - Internet-based strategies in teaching and research

Interactive health communication using Internet technologies is expanding the range and flexibility of intervention and teaching options available in preventive medicine and the health sciences. Advantages of interactive health communication include the enhanced convenience, novelty, and appeal of computer-mediated communication; its flexibility and interactivity; and automated processing. We outline some of these fundamental aspects of computer-mediated communication as it applies to preventive medicine. Further, a number of key pathways of information technology evolution are creating new opportunities for the delivery of professional education in preventive medicine and other health domains, as well as for delivering automated, self-instructional health behavior-change programs through the Internet. We briefly describe several of these key evolutionary pathways, We describe some examples from work we have done in Australia. These demonstrate how we have creatively responded to the challenges of these new information environments, and how they may be pursued in the education of preventive medicine and other health care practitioners and in the development and delivery of health behavior change programs through the Internet. Innovative and thoughtful applications of this new technology can increase the consistency, reliability, and quality of information delivered.

A randomized trial of a problem-based learning approach for teaching epidemiology

Purpose. To conduct a controlled trial of traditional and problem-based learning (PBL) methods of teaching epidemiology. Method. All second-year medical students (n = 136) at The University of Western Australia Medical School were offered the chance to participate in a randomized controlled trial of teaching methods fur an epidemiology course. Students who consented to participate (n = 80) were randomly assigned to either a PBL or a traditional course. Students who did not consent or did not return the consent form (n = 56) were assigned to the traditional course, Students in both streams took identical quizzes and exams. These scores, a collection of semi-quantitative feedback from all students, and a qualitative analysis of interviews with a convenience sample of six students from each stream were compared. Results. There was no significant difference in performances on quizzes or exams between PBL and traditional students. Students using PBL reported a stronger grasp of epidemiologic principles, enjoyed working with a group, and, at the end of the course, were more enthusiastic about epidemiology and its professional relevance to them than were students in the traditional course. PBL students worked more steadily during the semester but spent only marginally more time on the epidemiology course overall. Interviews corroborated these findings. Non-consenting students were older (p < 0.02) and more likely to come from non-English-speaking backgrounds (p < 0.005). Conclusions. PBL provides an academically equivalent but personally far richer learning experience. The adoption of PBL approaches to medical education makes it important to study whether PBL presents particular challenges for students whose first language is not the language of instruction.

Cervical screening: population-based comparisons between self-reported survey and registry-derived Pap test rates

Objective: To compare self-reported cervical screening rates, as recorded in the 1998 NSW Health Survey, with registry-based cervical screening rates for NSW for the same period; and to examine factors associated with over-estimates of cervical screening rates by self-report. Methods: Self-reported cervical screening data was extracted from the 1998 NSW Health Survey, biennial screening rates estimated and compared with biennial cervical screening rates for 1997-98, as recorded on the NSW Pap Test Register (PTR). Rates and differences were related to socio-demographic characteristics of the 17 Area Health Services of NSW. Results: According to the 1998 NSW Health Survey, 74% of women reported having a Pap test during the previous two years. The equivalent rate recorded on the NSW PTR for 1997-98 was 62% (p

Active and passive smoking and the risk of subarachnoid hemorrhage - An international population-based case-control study

Background and Purpose - This study was undertaken to better clarify the risks associated with cigarette smoking and subarachnoid hemorrhage (SAH). Methods - The study included 432 incident cases of SAH frequency matched to 473 community SAH-free controls to determine dose-dependent associations of active and passive smoking ( at home) and smoking cessation with SAH. Results - Compared with never smokers not exposed to passive smoking, the adjusted odds ratio for SAH among current smokers was 5.0 (95% confidence interval [CI], 3.1 to 8.1); for past smokers, 1.2 ( 95% CI, 0.8 to 2.0); and for passive smokers, 0.9 ( 95% CI, 0.6 to 1.5). Current and lifetime exposures showed a clear dose-dependent effect, and risks appeared more prominent in women and for aneurysmal SAH. Approximately 1 in 3 cases of SAH could be attributed to current smoking, but risks decline quickly after smoking cessation, even among heavy smokers. Conclusions - A strong positive association was found between cigarette smoking and SAH, especially for aneurysmal SAH and women, which is virtually eliminated within a few years of smoking cessation. Large opportunities exist for preventing SAH through smoking avoidance and cessation programs.

Program sustainability of a community-based intervention to prevent falls among older Australians

Multi-strategy interventions have been demonstrated to prevent falls among older people, but studies have not explored their sustainability. This paper investigates program sustainability of Stay on Your Feet (SOYF), an Australian multi-strategy falls prevention program (1992-1996) that achieved a significant reduction in falls-related hospital admissions. A series of surveys assessed recall, involvement and current falls prevention activities, 5 years post-SOYF in multiple original SOYF stakeholder groups within the study area [general practitioners (GPs), pharmacists, community health (CH) staff shire councils (SCs) and access committees (ACs)]. Focus groups explored possible behavioural changes in the target group. Surveys were mailed, except to CH staff and ACs. who participated in guided group sessions and were contacted via the telephone, respectively. Response rates were: GPs. 67% (139/209); pharmacists, 79% (53/67); CH staff, 63% (129/204); SCs, 90% (9/10); ACs, 80% (8/10). There were 73 older people in eight focus groups. Of 117 GPs who were practising during SOYF 80% recalled SOYF and 74% of these reported an influence on their practice. Of 46 pharmacists operating a business during SOYF, 45% had heard of SOYF and 79% of these reported being 'somewhat' influenced. Of 76 community health staff (59%) in the area at that time, 99% had heard of SOYF and 82% reported involvement. Four SCs retained a SOYF resource, but none thought current activities were related. Seven ACs reported involvement, but no activities were sustained. Thirty-five focus group participants (48%) remembered SOYF and reported a variety of SOYF-initiated behaviour changes. Program sustainability was clearly demonstrated among health practitioners. Further research is required to assess long-term effect sustainability.

Improving access to evidence-based mental health care: general practitioners and allied health professionals collaborate

This study evaluated whether projects conducted through the Access to Allied Health Services component of the Australian Better Outcomes in Mental Health Care initiative are improving access to evidence-based, non-pharmacological therapies for people with depression and anxiety. Synthesising data from the first 29 projects funded through the initiative, the study found that the models utilised in the projects have evolved over time. The projects have achieved a high level uptake; at a conservative estimate, 710 GPs and 160 allied health professionals (AHPs) have provided care to 3,476 consumers. The majority of these consumers have depression (77%) and/or anxiety disorders (55%); many are low income earners (57%); and a number have not previously accessed mental health care (40%). The projects have delivered 8,678 sessions of high quality care to these consumers, most commonly providing CBT-based cognitive and behavioural interventions (55% and 41%, respectively). In general, GPs, AHPs and consumers are sanguine about the projects, and have reported positive consumer outcomes. However, as with any new initiative, there are some practical and professional issues that need to be addressed. The projects are improving access to evidence-based, non-pharmacological therapies. The continuation and expansion of the initiative should be a priority.

Cancer detection and mammogram volume of radiologists in a population-based screening programme

This study investigates the relationship between the number of screening mammograms read by radiologists and the screening breast cancer detection rate. Cancer detection rates for incident screens (all women aged >= 40 years) were compared by increasing categories of reader volume using Poisson regression. Data from New South Wales (NSW) for a 2 year period (2000-2001) were obtained from the BreastScreen NSW programme. Cancer detection rates increased with the number of mammograms read in the programme, reaching a plateau of approximately 40 per 10,000 after 1375 mammograms per year. No significant differences in cancer detection were evident above 875 mammograms (compared to below 875 mammograms) per year (RR = 0.79, 95% CI 0.63-0.99). (c) 2005 Elsevier Ltd. All rights reserved.

Caring for someone with dementia in a rural town .2. Services

Dementia care in rural areas is in need of attention from researchers, planners and policy makers. Family carers in these areas face some significant challenges, in terms of managing the care where support services are often unavailable or inaccessible. This paper reports on a qualitative study in which a group of rural based carers participated in a focus group and interviews. Through this process, the carers' perceptions of support services were explored. Content analysis of the data revealed that, despite a number of supportive aspects of rural life, these carers felt in need of more services, a finding supported by current literature.

Latent class analysis of manic and depressive symptoms in a population-based sample in Sao Paulo, Brazil

Background: Current diagnostic criteria cannot capture the full range of bipolar spectrum. This study aims to clarify the natural co-segregation of manic-depressive symptoms occurring in the general population. Methods: Using data from the Sao Paulo Catchment Area Study, latent class analysis (LCA) was applied to eleven manic and fourteen depressive symptoms assessed through CIDI 1.1 in 1464 subjects from a community-based study in Sao Paulo, Brazil. All manic symptoms were assessed, regardless of presence of euphoria or irritability, and demographics, services used, suicidality and CIDI/DSM-IIIR mood disorders used to external validate the classes. Results: The four obtained classes were labeled Euthymics (EU; 49.1%), Mild Affectives (MA; 31.1%), Bipolars (BIP; 10.7%), and Depressives (DEP; 9%). BIP and DEP classes represented bipolar and depressive spectra, respectively. Compared to DEP class, BIP exhibited more atypical depressive characteristics (hypersomnia and increase in appetite and/or weight gain), risk of suicide, and use of services. Depressives had rates of atypical symptoms and suicidality comparable to oligosymptomatic MA class subjects. Limitations: The use of lay interviewers and DSM-IIIR diagnostic criteria, which are more restrictive than the currently used DSM-IV TR. Conclusions: Findings of high prevalence of bipolar spectrum and of atypical symptoms and suicidality as indicators of bipolarity are of great clinical importance, due to different treatment needs, and higher severity. Lifetime sub-affective and syndromic manic symptoms are clinically significant, arguing for the need Of revising DSM bipolar spectrum categories. (C) 2009 Elsevier B.V. All rights reserved.