G. La Rosa

Changing patterns of hepatitis A virus infection in children in Palermo, Italy.

In 1988 in Palermo, Italy the prevalence of antibodies to hepatitis A virus (anti-HAV) in a sample of 490 children 6–13 years old was 10.6%; it increased from 6.3% among children 6–10 years old to 14.7% in children 11–13 years old (P < 0.01).Compared with findings from a survey conducted in 1978 in the same area, the results of the present study show a significant (P < 0.01) reduction in the anti-HAV prevalence in both age groups.Anti-HAV prevalence was inversely related to the fathers years of education and positively related to the family size. Children of fathers with less than 6 years of schooling had a 3.2-fold risk (C.I. 95% = 1.3–8.1), and children with five or more members in their households had a 2.7-fold risk (C.I. 95% = 1.1–6.4) of previous exposure to hepatitis A virus (HAV) infection.Our findings indicate that exposure of children in Palermo to HAV is decreasing significantly, probably because of improvements in socio-economic conditions during recent years; however socio-demographic factors appear to be important determinants of infection.

The IBIS Gamma-Ray telescope on INTEGRAL

The IBIS Telescope is the high angular resolution Gamma-Ray imager on-Board the INTEGRAL Satellite. IBIS features a coded aperture mask and a novel large area (∼3,000 cm2) multilayer detector which utilises both Cadmium Telluride (16,384 detectors) and Caesium Iodide elements (4,096 detectors) to provide the fine angular resolution ∼12 arcmin, wide spectral response (20 keV to 10 MeV), high resolution timing (61 μs) and spectroscopy (6% at 100 keV) required to satisfy the mission’s imaging objectives. This paper will focus on the IBIS hardware characteristics while the Scientific Performance of the telescope have been recently addressed elsewhere [1].

Epidemiological aspects of hepatitis B in Palermo: changes in HBV spread.

Prevalence of HBV infection in Palermo was investigated in 1989, in comparison with similar data observed in 1982.Between September 1988 and April 1989, 1001 serum samples taken from healthy individuals or from patients with pathology unrelated to liver diseases, in the age groups 0 to 59 years, were collected.Prevalence of HBsAg and anti-HBc was, respectively, 2.7% and 24.3% in males, 2.3% and 19% in females. Prevalence was inversely related to socioeconomic level as defined by occupation, educational level and area of residence.Prevalence of HBV markers in 1989 was compared with that of a sample of sera taken in 1982 and stored at -20°C.Prevalence was lower in 1989 for age groups under 20, while no difference was seen in older age groups.

FINAL PERFORMANCES OF THE X-RAY MIRRORS OF THE JET-X TELESCOPE

The Joint European X-ray Telescope (JET-X) is one of the core scientific instruments of the SPECTRUM RONTGEN-ϒ astrophysics mission. The project is a collaboration of British, Italian and Russian consortia, with the participation of the Max Planck Institut (Germany). JET-X was designed to study the emission from X-ray sources in the band of 0.3–10 keV. Citterio et al. (1996 and references therein) describe its structure, composed by two identical and coaligned Wolter I telescopes. Focal plane imaging is provided by cooled X-ray sensitive CCD detectors which combine high spatial resolution with good spectral resolution, including coverage of the iron line complex around 7 keV at a resolution of ΔE/E ∼ 2%.