Hepatitis B virus prevalence in two institutions for the mentally handicapped

A comparative study of the prevalence of hepatitis B virus infection in two institutions for the mentally handicapped was carried out between April and November 1989 and April and August 1991. The institutions were situated within 10 km of each other in north-eastern Johannesburg. One institution had a significantly higher prevalence of virus markers, 68% (139 of 203) compared with 23% (40 of 176), was in poorer condition and had more severely handicapped residents with more aggressive behaviour. However, the most important difference between the two institutions was that residents at the higher-prevalence institution were admitted at a considerably younger age. Younger individuals appear to be more susceptible to infection and are more likely to develop persistent infection, thus contributing to a greater pool of infection in the institution

Primary and secondary infection with human parvovirus B19 in pregnant women in South Africa

A study of human parvovirus B19 infection in 1 967 pregnant women of all races in Johannesburg revealed an overall prevalence of 24,9% for IgG antibodies and 3,3% for IgM antibodies. Of the 64 IgM-positive sera indicating active infection, 62 were resistant to urea denaturation. No differences in the prevalence of IgG antibodies between population groups were observed, but active infections, as demonstrated by IgM antibodies, were significantly more prevalent in black than in white, coloured or Asian mothers

Evaluation of the World Health Organisation' antibody-testing strategy for the individual patient diagnosis of HIV infection (strategy Ill)

No Abstract

Is antenatal screening for rubella and cytomegalovirus justified?

Altogether 2 250 asymptomatic pregnant women attending an antenatal clinic were investigated for serological evidence of past exposure to rubella and cytomegalovirus (CMV) as well as for active primary infection or reinfection/ reactivation. Only 7 (0,3%) active rubella infections were diagnosed, none of them primary. Similarly, out of 132 patients with active CMV, only 5 primary infections (3,8%) were diagnosed; the vast majority 127 (96%)- had reactivation infections. No congenital rubella infections were detected, while the transplacental transmission rate for CMV was 6,4%. None of the infants followed up was clinically affected at birth or at 6 months. No racial differences in seroprevalences for CMV or rubella immunoglobulin were observed, but immunoglobulin antibody prevalence to CMV was significantly lower in the white group. From this study there appeared to be no indication for routine antenatal screening for CMV in asymptomatic mothers

GW190814: gravitational waves from the coalescence of a 23 solar mass black hole with a 2.6 solar mass compact object

We report the observation of a compact binary coalescence involving a 22.2–24.3 Me black hole and a compact object with a mass of 2.50–2.67 Me (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO’s and Virgo’s third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of - + 241 45 41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with gravitational waves, - + 0.112 0.009 0.008, and its secondary component is either the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system. The dimensionless spin of the primary black hole is tightly constrained to �0.07. Tests of general relativity reveal no measurable deviations from the theory, and its prediction of higher-multipole emission is confirmed at high confidence. We estimate a merger rate density of 1–23 Gpc−3 yr−1 for the new class of binary coalescence sources that GW190814 represents. Astrophysical models predict that binaries with mass ratios similar to this event can form through several channels, but are unlikely to have formed in globular clusters. However, the combination of mass ratio, component masses, and the inferred merger rate for this event challenges all current models of the formation and mass distribution of compact-object binaries

Bluefin tuna (Thunnus thynnus) distribution in relation to sea surface temperature fronts in the Gulf of Maine (1994-96)

Fishery-linked aerial surveys for bluefin tuna (Thunnus thynnus) were conducted in the Gulf of Maine (GOM) from July through October, 1994-96. Each year, from 507 to 890 surface schools were detected and their locations examined in relation to oceanographic conditions. Correlations between bluefin tuna presence and environmental variables were explored for sea surface temperature (SST), distance to a SST front, frontal density (relative density of all SST fronts seen in a given 1 km area for 2 weeks prior to each tuna sighting), and bottom depth and slope. Mean SST associated with bluefin schools was 18.1degreesC (+/-2.8). Schools were located at a mean distance of 19.7 km (+/-19.6) from SST fronts, and in water masses with an average frontal density of 28.2 m km(-2) (+/-35.7). Mean bottom depth of detected schools was 139.0 m (+/-70.3), and mean bottom slope was 0.7% rise (+/-0.7). A binomial generalized linear model fit to these variables indicated that bluefin are seen closer to fronts than locations in which no tuna were seen. Using simple and partial Mantel tests, we investigated the spatial correlation between bluefin tuna presence and the environmental variables, controlling for spatial autocorrelation. For each day that schools were sighted, we performed 24 Mantel tests, on a combination of response and predictor variables. The spatial relationship between bluefin tuna and SST fronts was inconsistent. Our analysis identified significant spatial structure in the bluefin school locations that had no significant correlation with any of the measured environmental features, suggesting that other untested features, such as prey density, may be important predictors of bluefin distribution in the GOM.</p