2,247 research outputs found
Observing the Sunyaev-Zel'dovich Effect Closer to Home
Hot gas trapped in a dark matter halo will produce a decrement in the surface
brightness of the microwave background, the Sunyaev-Zel'dovich (SZ) effect.
While massive clusters produce the strongest central SZ decrements, we point
out that a local galaxy halo, specifically the halo of M31, may be one of the
brightest integrated SZ sources in the sky. For various realistic gas
distributions consistent with current X-ray limits, we show that the integrated
SZ decrement from M31 will be comparable to decrements already detected in more
distant sources, provided its halo contains an appreciable quantity of hot gas.
A measurement of this decrement would provide direct information on the mass,
spatial distribution and thermodynamic state of hot gas in a low-mass halo, and
could place important constraints on current models of galaxy formation.
Detecting such an extended (~ 10 degree), low-amplitude signal will be
challenging, but should be possible with all-sky SZ maps from satellite
missions such as the Wilkinson Microwave Anisotropy Probe or the Planck
Surveyor.Comment: 5 pages, 3 figures; submitted to MNRA
Saving mothers: 1999 - 2001
The 'big five' causes of maternal death in South Africa in the 3 years 1999 - 2001 were non-pregnancy-related infection (mainly AIDS), complications of hypertension in pregnancy, obstetric haemorrhage, pregnancy-related sepsis and pre-existing medical conditions. Women 35 years and older were at greater risk of dying than younger women, and women in their first pregnancy or who had had 5 or more pregnancies were also at greater risk. Recommendations have been made by the National Committee on Confidential Enquiries into Maternal Deaths (NCCEMD) that address the problems of avoidable factors. If implemented, these should result in a reduction of maternal deaths
Maternal serum fructosamine values after delivery of macrosomic babies and unexplained stillbirths
Measurement of serum fructosamine and haemoglobin A, levels and glucose tolerance tests were performed in 75 women in the immediate postpartum period. None had predisposing factors to gestational diabetes. They were divided into three groups: group I consisted of 15 women who delivered an unexplained stillbirth; group 11 of 30 women who gave birth to babies weighing between 2500 g and 3900 g at term; and group III of 30 women who delivered babies weighing≥ 4000 g. There was a significant difference in the mean level of serum fructosamine between the unexplained stillbirth and control groups (P < 0,001). Although the HbA, values varied in the three groups, there was a significant difference between the unexplained stillbirth group and the macrosomic infant group (P < 0,05). All patients had normal glucose tolerance tests
Rising rates of Caesarean sections: an audit of Caesarean sections in a specialist private practice
Background: Caesarean section (CS) rates are increasing worldwide; rates in the private sector in South Africa are reported to be particularly high.To the best of our knowledge there has been no recent audit of Caesarean sections performed by the private health sector in KwaZulu-Natal. The aimof this study was to carry out an audit of CS in a private practice.Methods: An audit of the patient records over a period of one year was done. No personal identifiers were noted or reported on. All relevant clinicaldata were pooled and used to analyse the clinical information.Results: There were 364 deliveries in the study period and 209 of these were CS, giving a rate of 60.4%. Most of the caesarean sections were carriedout because of a previous CS; maternal request and HIV status also contributed to the high rate.Conclusion: The high CS rate in private practice is probably a window to the increased rates of Caesarean section being performed worldwide.This high rate is in keeping with trends in countries such as South America, and is considerably higher than the ideal rate of 10 to 15% in low-riskobstetric populations suggested by the WHO
Late termination of pregnancy by intracardiac potassium chloride injection: 5 years’ experience at a tertiary referral centre
Objectives. To report our experience with intracardiac potassium chloride (KCl) injection as a method of feticide for severe congenital abnormalities beyond 24 weeksf gestation.Method. A retrospective chart review. Patient demographics and types of fetal anomalies were analysed according to the groups that acceptedor declined late termination of pregnancy (LTOP, .24 weeks) for severe congenital abnormalities.Results. Of 3 896 women referred to the Fetal Medicine Unit at Inkosi Albert Luthuli Central Hospital, KwaZulu-Natal, 2 209 (56.7%) were at .24weeksf gestation at their first visit. LTOP for severe congenital abnormalities was offered to 253 (11.5%), of whom 191 (75.5%) accepted. Differences in maternal age, parity, race and religion were not statistically significant. The type of fetal abnormalities and gestational age at diagnosis influenced the decision-making process in >80% of the women. The most frequent indications for LTOP were brain and spinal abnormalities (53.0%), and aneuploidy (20.6%). Feticide by ultrasound-guided intracardiac KCl injection was performed in 138/191 cases (72.2%); 53 women who accepted LTOP did not undergo feticide for a variety of reasons. The mean interval between diagnosis and performance of feticide was 10 days (range 0 - 42 days). Fetal asystole was achieved in all cases within 2 minutes by a single-needle injection of intracardiac KCl; the mean duration of the procedure was 12 minutes (range 6 - 25 minutes). There were no maternal complications, and stillbirths occurred in all cases.Conclusion. Feticide by ultrasound-guided intracardiac KCl injection was an acceptable, safe and effective method for LTOP. Further studies are needed to determine the minimum dosage of KCl required to achieve the desired effect
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