5,955 research outputs found

    Policies, Legislation and Organizations Related to Water in South Africa, with Special Reference to the Olifants River Basin

    Get PDF
    water resources management / river basins / water use / organizations / institutions / mapping / government / political aspects / ethnology / social status / water policy / water law / land tenure / water supply /sanitation / water users / land use / conflict / private sector / nongovernmental organizations / local government / water user associations / catchment areas / monitoring / South Africa / Olifants river basin / Steelpoort river basin

    Effect of detraining on bone and muscle tissue in subjects with chronic spinal cord injury after a period of electrically-stimulated cycling: a small cohort study

    Get PDF
    Objective: To investigate adaptive changes in bone and muscle parameters in the paralysed limbs after de-training or reduced functional electrical stimulation (FES) induced cycling following high-volume FES-cycling in chronic spinal cord injury (SCI). Subjects: Five subjects with motor-sensory complete SCI (age 38.6 years, lesion duration 11.4 years) were included. Four subjects stopped FES-cycling completely after the training phase whereas one continued reduced FES-cycling (2-3 times/week, for 30min). Methods: Bone and muscle parameters were assessed in the legs using peripheral quantitative computed tomography at six and twelve months after cessation of high-volume FES-cycling. Results: Gains achieved in the distal femur by high-volume FES-cycling were partly maintained at one year of detraining: 73.0% in trabecular bone mineral density (BMD), 63.8% in total BMD, 59.4% in bone mineral content and 22.1% in muscle cross-sectional area (CSAmuscle) in the thigh. The subject who continued reduced FES-cycling maintained 96.2% and 95.0% of the previous gain in total and trabecu-lar BMD, and 98.5% in CSAmuscle. Conclusion: Bone and muscle benefits achieved by one year of high-volume FES-cycling are partly preserved after 12 months of detraining whereas reduced cycling maintains bone and muscle mass gained. This suggests that high-volume FES-cycling has clinical relevance for at least 1y after detraining

    Long-term low-dose ketoconazole treatment in bilateral macronodular adrenal hyperplasia

    Get PDF
    Medical therapy for Cushing's syndrome due to bilateral macronodular adrenal hyperplasia (BMAH) is generally administered for a limited time before surgery. Aberrant receptors antagonists show inconsistent efficacy in the long run to prevent adrenalectomy. We present a patient with BMAH, treated for 10 years with low doses of ketoconazole to control cortisol secretion. A 48-year-old woman presented with headaches and hypertension. Investigations showed the following: no clinical signs of Cushing's syndrome; enlarged lobulated adrenals; normal creatinine, potassium, and aldosterone; normal urinary aldosterone and metanephrines; elevated urinary free cortisol and steroid metabolites; and suppressed plasma renin activity and ACTH. A screening protocol for aberrant adrenal receptors failed to show any illegitimate hormone dependence. Ketoconazole caused rapid normalisation of cortisol and ACTH that persists over 10 years on treatment, while adrenals show no change in shape or size. Ketoconazole decreases cortisol in patients with Cushing's syndrome, and may prevent adrenal overgrowth. Steroid secretion in BMAH is inefficient as compared with normal adrenals or secreting tumours and can be controlled with low, well-tolerated doses of ketoconazole, as an alternative to surgery. LEARNING POINTS: Enlarged, macronodular adrenals are often incidentally found during the investigation of hypertension in patients harboring BMAH. Although laboratory findings include low ACTH and elevated cortisol, the majority of patients do not display cushingoid features.Bilateral adrenalectomy, followed by life-long steroid replacement, is the usual treatment of this benign condition, and alternative medical therapy is sought. Therapy based on aberrant adrenal receptors gives disappointing results, and inhibitors of steroidogenesis are not always well tolerated.However, ketoconazole at low, well-tolerated doses appeared appropriate to control adrenal steroid secretion indefinitely, while preventing adrenal overgrowth. This treatment probably constitutes the most convenient long-term alternative to surgery

    Hydro-institutional mapping in the Steelpoort River Basin, South Africa

    Get PDF
    River basins / Institutions / Organizations / Private sector / Public sector / Local government / Mapping / Water resource management / Water policy / Legislation / Rural women / Constraints / Groundwater / Surface water / Water quality / Water use / Water users / Dams / Reservoirs / Large-scale systems / Irrigation management / Industrialization / Case studies / Operations / Maintenance / Canals / Conflict / Farmer-agency interactions / Policy / Water supply / Rural development

    Superconductivity and charge carrier localization in ultrathin La1.85Sr0.15CuO4/La2CuO4\mathbf{{La_{1.85}Sr_{0.15}CuO_4}/{La_2CuO_4}} bilayers

    Get PDF
    La1.85Sr0.15CuO4\mathrm{La_{1.85}Sr_{0.15}CuO_4}/La2CuO4\mathrm{La_2CuO_4} (LSCO15/LCO) bilayers with a precisely controlled thickness of N unit cells (UCs) of the former and M UCs of the latter ([LSCO15\_N/LCO\_M]) were grown on (001)-oriented {\slao} (SLAO) substrates with pulsed laser deposition (PLD). X-ray diffraction and reciprocal space map (RSM) studies confirmed the epitaxial growth of the bilayers and showed that a [LSCO15\_2/LCO\_2] bilayer is fully strained, whereas a [LSCO15\_2/LCO\_7] bilayer is already partially relaxed. The \textit{in situ} monitoring of the growth with reflection high energy electron diffraction (RHEED) revealed that the gas environment during deposition has a surprisingly strong effect on the growth mode and thus on the amount of disorder in the first UC of LSCO15 (or the first two monolayers of LSCO15 containing one CuO2\mathrm{CuO_2} plane each). For samples grown in pure N2O\mathrm{N_2O} gas (growth type-B), the first LSCO15 UC next to the SLAO substrate is strongly disordered. This disorder is strongly reduced if the growth is performed in a mixture of N2O\mathrm{N_2O} and O2\mathrm{O_2} gas (growth type-A). Electric transport measurements confirmed that the first UC of LSCO15 next to the SLAO substrate is highly resistive and shows no sign of superconductivity for growth type-B, whereas it is superconducting for growth type-A. Furthermore, we found, rather surprisingly, that the conductivity of the LSCO15 UC next to the LCO capping layer strongly depends on the thickness of the latter. A LCO capping layer with 7~UCs leads to a strong localization of the charge carriers in the adjacent LSCO15 UC and suppresses superconductivity. The magneto-transport data suggest a similarity with the case of weakly hole doped LSCO single crystals that are in a so-called {"{cluster-spin-glass state}"

    Simultaneous multi-band detection of Low Surface Brightness galaxies with Markovian modelling

    Get PDF
    We present an algorithm for the detection of Low Surface Brightness (LSB) galaxies in images, called MARSIAA (MARkovian Software for Image Analysis in Astronomy), which is based on multi-scale Markovian modeling. MARSIAA can be applied simultaneously to different bands. It segments an image into a user-defined number of classes, according to their surface brightness and surroundings - typically, one or two classes contain the LSB structures. We have developed an algorithm, called DetectLSB, which allows the efficient identification of LSB galaxies from among the candidate sources selected by MARSIAA. To assess the robustness of our method, the method was applied to a set of 18 B and I band images (covering 1.3 square degrees in total) of the Virgo cluster. To further assess the completeness of the results of our method, both MARSIAA, SExtractor, and DetectLSB were applied to search for (i) mock Virgo LSB galaxies inserted into a set of deep Next Generation Virgo Survey (NGVS) gri-band subimages and (ii) Virgo LSB galaxies identified by eye in a full set of NGVS square degree gri images. MARSIAA/DetectLSB recovered ~20% more mock LSB galaxies and ~40% more LSB galaxies identified by eye than SExtractor/DetectLSB. With a 90% fraction of false positives from an entirely unsupervised pipeline, a completeness of 90% is reached for sources with r_e > 3" at a mean surface brightness level of mu_g=27.7 mag/arcsec^2 and a central surface brightness of mu^0 g=26.7 mag/arcsec^2. About 10% of the false positives are artifacts, the rest being background galaxies. We have found our method to be complementary to the application of matched filters and an optimized use of SExtractor, and to have the following advantages: it is scale-free, can be applied simultaneously to several bands, and is well adapted for crowded regions on the sky.Comment: 39 pages, 18 figures, accepted for publication in A
    • 

    corecore