A school-based randomized controlled trial of peer-led sex education in England.

This article discusses the design of an ongoing cluster-randomized trial comparing two forms of school-based sex education in terms of educational process and sexual health outcomes. Twenty-nine schools in southern England have been randomized to either peer-led sex education or to continue with their traditional teacher-led sex education. The primary objective is to determine which form of sex education is more effective in promoting young people's sexual health. The trial includes an unusually detailed evaluation of the process of sex education as well as the outcomes. The sex education programs were delivered in school to pupils ages 13-14 years who are being followed until ages 19-20. Major trial outcomes are unprotected sexual intercourse and regretted intercourse by age 16 and cumulative incidence of abortion by ages 19-20. We discuss the rationale behind various aspects of the design, including ethical issues and practical challenges of conducting a randomized trial in schools, data linkage for key outcomes to reduce bias, and integrating process and outcome measures to improve the interpretation of findings.

Workplace supports, job performance, and integration outcomes for people with psychiatric disabilities.

The notion of natural workplace supports is an essential ingredient in achieving successful supported employment outcomes. This quantitative study examines the characteristics of 243 individuals with psychiatric disabilities participating in supported employment programs in the United States. Diagnoses, psychiatric symptoms, and Global Assessment of Functioning were evaluated in relation to supported employment outcomes, including social interaction, wages, and workplace supports. The results of this study indicate that social interaction and natural workplace supports improve supported employment outcomes for individuals with psychiatric disabilities.

Behavioural intervention trials for HIV/STD prevention in schools: are they feasible?

OBJECTIVE: To assess the feasibility of conducting a large randomised controlled trial (RCT) of peer led intervention in schools to reduce the risk of HIV/STD and promote sexual health. METHODS: Four secondary schools in Greater London were randomly assigned to receive peer led intervention (two experimental schools) or to act as control schools. In the experimental schools, trained volunteers aged 16-17 years (year 12) delivered the peer led intervention to 13-14 year old pupils (year 9). In the control schools, year 9 pupils received the usual teacher led sex education. Questionnaire data collected from year 9 pupils at baseline included views on the quality of sex education/intervention received, and knowledge and attitudes about HIV/AIDS and other sexual matters. Focus groups were also conducted with peer educators and year 9 pupils. Data on the process of delivering sex education/intervention and on attitudes to the RCT were collected for each of the schools. Analysis focused on the acceptability of a randomised trial to schools, parents, and pupils. RESULTS: Nearly 500 parents were informed about the research and invited to examine the study questionnaire; only nine raised questions and only one pupil was withdrawn from the study. Questionnaire completion rates were around 90% in all schools. At baseline, the majority of year 9 pupils wanted more information about a wide range of sexual matters. Focus group work indicated considerable enthusiasm for peer led education, among peer educators and year 9 pupils. Class discipline was the most frequently noted problem with the delivery of the peer led intervention. CONCLUSION: Evaluation of a peer led behavioural intervention through an RCT can be acceptable to schools, pupils, and parents and is feasible in practice. In general, pupils who received the peer led intervention responded more positively than those in control schools. A large RCT of the long term (5-7 year) effects of this novel intervention on sexual health outcomes is now under way.

Interference cancellation in respiratory sounds via a multiresolution joint time-delay and signal-estimation scheme.

This paper is concerned with the problem of cancellation of heart sounds from the acquired respiratory sounds using a new joint time-delay and signal-estimation (JTDSE) procedure. Multiresolution discrete wavelet transform (DWT) is first applied to decompose the signals into several subbands. To accurately separate the heart sounds from the acquired respiratory sounds, time-delay estimation (TDE) is performed iteratively in each subband using two adaptation mechanisms that minimize the sum of squared errors between these signals. The time delay is updated using a nonlinear adaptation, namely the Levenberg-Marquardt (LM) algorithm, while the function of the other adaptive system-which uses the block fast transversal filter (BFTF)-is to minimize the mean squared error between the outputs of the delay estimator and the adaptive filter. The proposed methodology possesses a number of key benefits such as the incorporation of multiple complementary information at different subbands, robustness in presence of noise, and accuracy in TDE. The scheme is applied to several cases of simulated and actual respiratory sounds under different conditions and the results are compared with those of the standard adaptive filtering. The results showed the promise of the scheme for the TDE and subsequent interference cancellation.

Reduced order Kalman filtering for the enhancement of respiratory sounds.

In the processing and analysis of respiratory sounds, heart sounds present the main source of interference. This paper is concerned with the problem of cancellation of the heart sounds using a reduced-order Kalman filter (ROKF). To facilitate the estimation of the respiratory sounds, an autoregressive (AR) model is fitted to heart signal information present in the segments of the acquired signal which are free of respiratory sounds. The state-space equations necessary for the ROKF are then established considering the respiratory sound as a colored additive process in the observation equation. This scheme does not require a time alignment procedure as with the adaptive filtering-based schemes. The scheme is applied to several synthesized signals with different signal-to-interference ratios (SIR) and the results are presented.

Iron-rich Basal sediments from the eastern equatorial pacific: leg 16, deep sea drilling project.

Iron-rich sediments chemically similar to those forming at present on the crest of the East Pacific Rise have been found just above basement at widely separated drill sites in the eastern equatorial Pacific, including three sites of Leg 16 of the Deep Sea Drilling Project. These sediments were probably formed when the basement was at the crest of this rise and have moved to their present location as a result of sea-floor spreading.