1,555 research outputs found
Better Clinical Diagnosis of Contraction of the Transverse Brim
The angle which the superior pubic rami make at the pubic symphysis is called the suprapubic angle. If the size of the suprapubic angle is less than the described norm of 1800 , the transverse diameter of the pelvic brim tends to be reduced. If, in addition, the shape of the suprapubic angle is angulated (Norman style) as opposed to arched (Roman style) the available transverse diameter is significantly less than the maximal transverse diameter, and the available true conjugate is less than the maximal true conjugate. The clinical technique of measuring the suprapubic angle is described and its clinical importance emphasised. Transverse brim contraction can be suspected by abdominal palpation. The author's method of abdominovaginal estimation of pelvic size is held to be superior to the generally accepted single-handed method.S. Afr. Med. J., 48, 781 (1974)
Gender reassignment surgery for male primary transsexuals
This article describes certain innovations and aspects of surgical technique together with some surgical assessments of results in a series of 58 operations for gender reassignment undertaken by the author over the past 24 years. The salient new features described are: (i) to prevent the early and late vaginal contractures that commonly follow previously accepted methods of neo-vagina construction, the technique of dissecting a new vaginal canal has been improved, and an improved skin graft (double-layered) is added to the peno-scroto-perineal flaps used to line the vaginal canal - these split-skin grafts, superimposed upon a meshed thick dermal graft, do not contract nearly as much as solitary splitskin grafts; (ii) the vagina is suspended laterally by the testicular cords, threaded above the superior pubic rami; and (iii) repeated intermittent use ofa vaginal vibrator is substituted for an indwelling vaginal mould, resulting in better compliance and a more pliable vagina.S Afr Med J 1993; 83: 347-34
A Reliable Method of Establishing the Level of the Fetal Head in Obstetrics
A method of assessing the level of the head clinically in 'fifths of the head above the pubic symphysis' is described, illustrated, and commented upon. Its value in delineating the descent of the head in problem cases, and as a guide to whether or not the. head can be delivered safely from below, has been proved in thousands of cases presenting with problems of disproportion at King Edward VIII Hospital, Durban. Confirmatory evidence by radiographic examination has been forthcoming in a largepercentage of cases. The traditional methods of assessing the level of thehead, by its 'station' and 'engagement', are described and subjected to criticism. They are theoretically unsound, and practically misleading, especially in problem cases.S. Afr. Med. J . 48, 784 (1974)
Extraperitoneal Lower Segment Caesarean Section for Infected Cases
Click on the link to view the abstract.S. Afr. Med. J., 48, 788 (1974)
High-pressure x-ray diffraction study of bulk and nanocrystalline PbMoO4
We studied the effects of high-pressure on the crystalline structure of bulk
and nanocrystalline scheelite-type PbMoO4. We found that in both cases the
compressibility of the materials is highly non-isotropic, being the c-axis the
most compressible one. We also observed that the volume compressibility of
nanocrystals becomes higher that the bulk one at 5 GPa. In addition, at 10.7(8)
GPa we observed the onset of an structural phase transition in bulk PbMoO4. The
high-pressure phase has a monoclinic structure similar to M-fergusonite. The
transition is reversible and not volume change is detected between the low- and
high-pressure phases. No additional structural changes or evidence of
decomposition are found up to 21.1 GPa. In contrast nanocrystalline PbMoO4
remains in the scheelite structure at least up to 16.1 GPa. Finally, the
equation of state for bulk and nanocrystalline PbMoO4 are also determined.Comment: 18 pages, 4 figure
Low-cost, aerial photographic inventory of tidal wetlands
There are no author-identified significant results in this report
Data-constrained assessment of ocean circulation changes since the middle Miocene in an Earth system model
Since the middle Miocene (15 Ma, million years ago), the Earth's climate has undergone a long-term cooling trend, characterised by a reduction in ocean temperatures of up to 7–8 ∘C. The causes of this cooling are primarily thought to be due to tectonic plate movements driving changes in large-scale ocean circulation patterns, and hence heat redistribution, in conjunction with a drop in atmospheric greenhouse gas forcing (and attendant ice-sheet growth and feedback). In this study, we assess the potential to constrain the evolving patterns of global ocean circulation and cooling over the last 15 Ma by assimilating a variety of marine sediment proxy data in an Earth system model. We do this by first compiling surface and benthic ocean temperature and benthic carbon-13 (δ13C) data in a series of seven time slices spaced at approximately 2.5 Myr intervals. We then pair this with a corresponding series of tectonic and climate boundary condition reconstructions in the cGENIE (“muffin” release) Earth system model, including alternative possibilities for an open vs. closed Central American Seaway (CAS) from 10 Ma onwards. In the cGENIE model, we explore uncertainty in greenhouse gas forcing and the magnitude of North Pacific to North Atlantic salinity flux adjustment required in the model to create an Atlantic Meridional Overturning Circulation (AMOC) of a specific strength, via a series of 12 (one for each tectonic reconstruction) 2D parameter ensembles. Each ensemble member is then tested against the observed global temperature and benthic δ13C patterns. We identify that a relatively high CO2 equivalent forcing of 1120 ppm is required at 15 Ma in cGENIE to reproduce proxy temperature estimates in the model, noting that this CO2 forcing is dependent on the cGENIE model's climate sensitivity and that it incorporates the effects of all greenhouse gases. We find that reproducing the observed long-term cooling trend requires a progressively declining greenhouse gas forcing in the model. In parallel to this, the strength of the AMOC increases with time despite a reduction in the salinity of the surface North Atlantic over the cooling period, attributable to falling intensity of the hydrological cycle and to lowering polar temperatures, both caused by CO2-driven global cooling. We also find that a closed CAS from 10 Ma to present shows better agreement between benthic δ13C patterns and our particular series of model configurations and data. A final outcome of our analysis is a pronounced ca. 1.5 ‰ decline occurring in atmospheric (and ca. 1 ‰ ocean surface) δ13C that could be used to inform future δ13C-based proxy reconstructions.</p
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