Juvenile offenders and hepatitis B: risk, vaccine uptake and vaccination status

OBJECTIVE: To determine the hepatitis B vaccination status of juvenile offenders in a custodial setting, their perceived risk of hepatitis B infection, and factors influencing vaccine uptake. DESIGN: 130 males aged 14-17 years resident at the Melbourne Juvenile Justice Centre for at least one week between mid-January and mid-December 1996 were invited to participate; 90 (69%) completed a doctor-administered questionnaire, and blood for serological testing was obtained from 83 of these participants. MAIN OUTCOME MEASURES: Whether hepatitis B vaccine had been offered; whether hepatitis B vaccine had been given; the presence of antibodies to hepatitis B and C; risk factors and self-perceived risk of hepatitis B. RESULTS: About a quarter of participants (22/83) had protective levels of antibody to hepatitis B surface antigen (anti-HBs). Forty (44%) participants reported having been offered hepatitis B vaccine; they were more likely to be vaccinated and have protective levels of anti-HBs. Perceived risk for bloodborne virus infection was low, although two-thirds of participants were at high risk of hepatitis B infection. On serological testing, 6.4% (5/78) were positive for antibody to hepatitis B core antigen (anti-HBc), and a further 2.6% (2) had equivocal antibody levels. Of the 71 who were negative for anti-HBc, 51 (71.8%) were negative for anti-HBs. CONCLUSIONS: The targeted hepatitis B vaccination program has not adequately protected this group at high lifetime risk of hepatitis B. Failure to deliver vaccine may reflect lack of contact with healthcare services, oversight in offering vaccine and reluctance of youth to participate in preventive healthcare measures, often through not seeing themselves to be at risk. Universal approaches to vaccination may be more successful in vaccinating this group.     

The structure of psychological distress and well-being in general populations.

Describes the development of the Mental Health Inventory (MHI), a 38-item measure of psychological distress and well-being, developed for use in general populations. The MHI was fielded in 4 large samples (N?=?5089) of Ss aged 13–69 yrs. One data set was used to explore the MHI's factor structure, and confirmatory factor analyses were used for cross validation. Results support a hierarchical factor model composed of a general underlying psychological distress vs well-being factor; a higher order structure defined by 2 correlated factors—Psychological Distress and Well-Being; and 5 correlated lower order factors—Anxiety, Depression, Emotional Ties, General Positive Affect, and Loss of Behavioral Emotional Control. Summated rating scales produced high internal consistency estimates and substantial stability over a 1-yr interval. Results provide strong psychometric support for a hierarchical model and scoring options ranging from 5 distinct constructs to reliance on 1 summary index. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Feedforward control with online parameter estimation applied to the Chylla–Haase reactor benchmark

The Chylla–Haase polymerization reactor is used as a benchmark problem to illustrate the potential of feedforward control design by extending the conventional cascade control in the framework of the two-degree-of-freedom control concept. To ensure an accurate temperature control, the feedforward control is adapted to different batch conditions and various products by an extended Kalman filter. The reaction heat and the heat transfer coefficient are estimated online based on simple physically motivated relations applicable to a wider range of batch reactors. Simulation results under model uncertainties show the effectiveness and accuracy of the adaptive feedforward control concept while maintaining the conventional feedback cascade control.     

MOVPE growth of GaN on Si - Substrates and strain

GaN on Si offers a promising technology for the low-cost production of wide-bandgap devices. Here, we present approaches towards the growth of GaN on technologically most relevant Si(001) substrates and methods to grow single-crystalline c-axis-oriented GaN on Si(001) with ω-scan FWHMs of 986 arc sec for the (0002) Bragg reflection. Strain is still the major issue for the established growth on Si(111). A study on the generation of strong tensile stress by Si-doping is presented. We find that tensile stress generation is dominantly dependent on the Si doping concentration and the edge dislocation density.     

Heat Treated NiP–SiC Composite Coatings: Elaboration and Tribocorrosion Behaviour in NaCl Solution

Tribocorrosion behaviour of heat-treated NiP and NiP–SiC composite coatings was investigated in a 0.6 M NaCl solution. The tribocorrosion tests were performed in a linear sliding tribometer with an electrochemical cell interface. It was analyzed the influence of SiC particles dispersion in the NiP matrix on current density developed, on coefficient of friction and on wear volume loss. The results showed that NiP–SiC composite coatings had a lower wear volume loss compared to NiP coatings. However, the incorporation of SiC particles into the metallic matrix affects the current density developed by the system during the tribocorrosion test. It was verified that not only the volume of co-deposited particles (SiC vol.%) but also the number of SiC particles per coating area unit (and consequently the SiC particles size) have made influence on the tribocorrosion behaviour of NiP–SiC composite coatings.