Duration of vaginal bleeding and trisomy at prenatal diagnosis

In the case-control study of 118 women with autosomal trisomy identified at prenatal diagnosis and their 442 karyotypically normal matched controls, we found that there was no overall association between risk of trisomy and the presence of vaginal bleeding during pregnancy. However, a lengthy duration of bleeding appears to predict increased risk of trisorny.     

Detection of low-grade mosaicism in fetal cells isolated from maternal blood

Recovering and analysing fetal erythrocytes from maternal blood is being pursued for non-invasive prenatal genetic diagnosis. We report the observation of 46, XY/47, XXY mosaicism in fetal cells from a woman whose first-trimester chorionic villus sampling (CVS) initially showed only 46, XY. Only after exhaustive (500 cells) analysis were four XXY cells found in cultured villi.     

Trace Element Concentrations and Bioindicator Responses in Tree Swallows from Northwestern Minnesota

Extremely high concentrations of cadmium (3.5 μg/g dry wgt.) and elevated concentrations of chromium (>10 μg/g dry wgt.) and mercury (1.6 μg/g dry wgt.) were reported in waterbird tissues at Agassiz National Wildlife Refuge in northwestern Minnesota in 1994. Tree swallows (Tachycineta bicolor) were studied during 1998–2001 at three drainages into the Refuge, two pools on the Refuge, and at a nearby reference location to document whether high levels of contaminants were still present, and if so to quantify the source and severity of the contamination. Trace elements were measured in tree swallow eggs, livers, and diet. Reproductive success and bioindicator responses were monitored. In 2000, water was drawn down on Agassiz Pool, one of the main pools on the Refuge. This presented an opportunity to evaluate the response of trace element concentrations in the diet and tissues of tree swallows after reflooding. High concentrations of trace elements were not detected in swallow tissues, nor were there differences among locations. Less than 20% of swallow samples had detectable concentrations of cadmium or chromium. Mercury concentrations were low and averaged <0.25 μg/g dry wgt. in swallow tissues. Trace elements, including mercury, did not increase in tree swallows following the 2000 drawdown at Agassiz Pool. Hatching success and survival of nestlings to 12 days-of-age for tree swallows on the Refuge were similar to the national average and consistent with background trace element concentrations. Bioindicator measurements were within the normal ranges as well.     

Legal aspects of pesticides and toxic substances testing requirements

Abstract

The United States Environmental Protection Agency administers several laws and progrms through which it reviews the hazard potential of pesticides and other toxic substances which may present a risk to human health or the environment. The Agency's ability to assess hazard as required by law depends in part on test data developed through testing standards in Agency regulations. In reviewing the Agency's actions in this regard, the courts emphasize the importance of reasoned regulatory decisions. The legal requirements to assess risk and provide reasoned decisions in this regard establish the legal importance of testing guidelines and test data, and indicate that sound test methodology is as important legally as it is scientifically.     

Coping,individual differences,and strain: A longitudinal study of short-term role overload

This study attempted to determine which personality dimensions and coping strategies would reduce or prevent strain in a context of naturally-occurring short-term role overload. Subjects were 106 adult undergraduate evening students enrolled in an intensive three-week summer school session. The median age was 26 years, and 72 per cent of the students worked full-time. Using a repeated-measures panel design, the study tested the effectiveness of three types of coping derived from Hall's (1972) typology. Longitudinal analysts using cross-lagged correlations and structural regressions showed little support for the predicted effects of Hall's three types of coping on subsequent strain. However, a fourth type of coping, Planned Task Management emerged during the analysis and showed a reciprocal relationship with strain. Both variables appeared to influence each other over time, although the effect of prior coping on subsequent strain was slightly but not significantly stronger. Also, alienation (defined as lack of commitment) had a significant moderator effect on the relationship between perceived overload and strain.     

New Zealand drivers study: developing a methodology for conducting a follow-up study of newly licensed drivers

PROBLEM: In recent years, there has been a significant reduction in traffic crash injury among young people, but they continue to be overrepresented in the traffic crash statistics. To improve this situation, sound scientific evidence is needed to develop effective policies and programs. METHOD: The aim of the proposed study is to provide this evidence by examining early driving and driving-related experiences of newly licensed drivers as they progress through the learner-, restricted-, and full-license stages of the graduated licensing system and to determine the impact of these experiences on subsequent negative traffic-related outcomes (risky driving behavior, injury traffic crashes, noninjury traffic crashes, infringements, convictions). Given the size and complexity of the proposed study, a comprehensive pilot study was undertaken to determine the feasibility of conducting a New Zealand-wide cohort study of newly licensed drivers. RESULTS: This article describes the pilot study process and the methodology that has been developed for the New Zealand-wide study.     

Graduated driver licensing: the New Zealand experience

In New Zealand, on 1 August 1987, a three-stage graduated driver licensing (GDL) system that applied to all new drivers aged 15-24 years was introduced. The essential elements of GDL were a 6-month learner license (supervised driving) and an 18-month restricted license stage (with restrictions on night driving and carrying passengers). A blood alcohol limit of 0.03 mg% applied at both stages. EVALUATION STUDIES: Early studies indicated that young people were reasonably accepting of the restrictions, with the passenger restriction being the least acceptable. Problems of compliance with the restricted license driving restrictions were reported. Evaluations of the impact of the graduated driver licensing (GDL) on serious traffic-related injury showed that up until 1991-1992, an 8% reduction could be attributed to GDL. At this time, it was considered that reduced exposure was the main reason for this reduction. However, the number of fatalities and hospital admissions among young people continued to decline, as did the population rate and the rate per number of licensed drivers among the young driver age group. A further evaluation study showed that drivers with a restricted license had a smaller proportion of crashes at night, and with passengers, compared with drivers licensed before GDL. IMPACT OF GDL: These results suggested that GDL restrictions had contributed to the reduction in crashes among young people and that it was not simply a case of reduced exposure to risk. An update of the most recent crash statistics indicated that, compared with older age groups, the fatal and serious injury crash rate among young people has remained substantially below the pre-GDL level. This suggests that the impact of GDL has not diminished over time.     

Stewardship Volunteering by Older Australians: The Generative Response

The aim of this paper is to use Erikson's approach to human development, and specifically generativity, as a framework by which to explore older people's experiences of environmental stewardship activities. Using data from a large qualitative study of environmental volunteers resident in the coastal fringes of Queensland, Australia, the paper provides important, illustrative, empirical support for Erikson's theory of generativity in later life. Findings suggest that older people are much more likely to connect their environmental actions with the longer-term future, and express a need to leave a lasting legacy for future generations. According to respondents, the later years are a time to contribute to the environment as part of a broader cycle of life. The environment is also an important site for intergenerational activities. Whilst the work presented here is only a small, localized study, use of Erikson's theory of human development as a framework helps demonstrate the importance of a generative response in later life.     

Preconditions of three types of alienation in young managers and professionals

The study tested predictions derived from Korman (1977) and from Sarason (1977) about factors leading to alienation among occupationally-successful young adults. The sample consisted of 434 college graduates (median age = 29 years), 85 per cent of whom were employed full-time. Respondents completed self-report questionnaires including measures of family and college background; expectations at college graduation for positive outcomes in personal, interpersonal, and work areas; current fulfilment in each of these areas; and alienation (estrangement from self, other people, and occupation or profession). Results of subgroup analysis showed that respondents whose backgrounds included high socio-economic status and graduation from elite colleges were more likely than other subjects to experience alienation when encountering lack of fulfilment. However, moderator regressions failed to show similar moderator effects, indicating that family and college backgrounds may produce discontinuous and qualitatively different subgroup effects. One implication of this study is to suggest more care in selecting individuals for high-risk job assignments with low probability of success.