146 research outputs found
The value of supplementary feeding to pre-weaned and weaned lambs grazing Italian ryegrass
The variation in, and often the disappointingly poor weight gains and the inability of lambs to achieve desirable carcass grades on ryegrass pastures have long been a concern to researchers, extension officers, advisors and farmers. The objectives of this study were to investigate whether concentrate supplementation to lambs on Italian ryegrass (Lolium multiflorum cv Midmar) pastures would improve the performance of lambs, and what the optimum level of supplementation is to lambs on the pasture. The investigation extended over the pre- and post-weaning growth phases of lambs and was conducted during two consecutive seasons at the Cedara Research Station in the KwaZulu-Natal Mistbelt. The pre-weaning stocking rate applied, was 20 South African Mutton Merino ewes with lambs/ha and the following treatments were applied: Control: continuous grazing - no creep feed; forward creep grazing by the lambs in a rotational grazing system where the lambs were allowed to graze paddocks allocated to the ewes, plus the next paddock in their series of grazing paddocks; 100 g creep feed/lamb/day; 250 g creep feed/lamb/day and creep feed ad libitum. The post-weaning stocking rate applied, was 50 lambs/ha and treatments were: Control - no supplement; 250 g of supplement/lamb/day (only the second season); 500 g of supplement/lamb/day and supplement ad libitum. From 42 days of age to weaning, supplementation significantly improved the live weight gain of suckling lambs. Creep feed intake varied between 300 and 350 g/lamb/day. The average daily gain of the weaned lambs improved significantly with supplementation. No significant advantage in terms of growth was gained by supplementing the weaned lambs at levels of higher than 500 g/day.
South African Journal of Animal Science Vol.32(1) 2002: 30-3
The value of Kikuyu foggage for overwintering dry ewes
Kikuyu (Pennisetum clandestinum) is a summer growing tropical pasture species well adapted to the Midlands of KwaZulu-Natal. Kikuyu foggage (standing hay) could play an important role in a fodder flow programme to sustain dry ewes during late winter after their lambs have been weaned in mid-winter. The potential of kikuyu foggage to supply in the feed requirements of dry ewes was evaluated over four winter periods. The foggage was obtained by closing off the kikuyu to grazing during either late January or late February. The foggage was grazed for eight weeks, from mid-July to mid-September, using either strip or continuous grazing systems. Closing off date did not significantly influence the chemical composition of the material on offer. The ewes in the different treatments lost between 4.7 and 10.3% of their initial body weight over the grazing period. In vitro digestible organic matter (IVDOM) of the foggage declined as winter progressed and was positively correlated with the body weight loss of the ewes. Foggage utilization varied between 36.7 and 43.5%, indicating a high proportion of fodder wastage. The body weight loss of the dry ewes during the grazing period suggested that kikuyu foggage in the KwaZulu-Natal Midlands was unable to sustain the body weight of the dry ewe.
South African Journal of Animal Science Vol.32(1) 2002: 7-1
New Selective Estrogen Receptor Modulators (SERMs) in Development
Selective estrogen receptor modulators (SERMs) or estrogen agonists/antagonists have shown promise in osteoporosis in that they have the potential to reduce the risk of fracture, and also reduce the risk of breast cancer. SERMs maybe classified according to their core structure, which is typically a variation of the 17 beta-estradiol template and subclassified according to the side chain at the helix 12 affector region. The best known are the triphenylethylenes such as tamoxifen, used in the management of breast cancer. However, the clinical application of this class of SERMs has been limited due to endometrial stimulation. A second class is the benzothiophenes such as raloxifene and arzoxifene, which have skeletal benefit with little, if any, uterine stimulation. Indole-based SERMs such as bazedoxifene have a 2-phenyl ring system that serves as a core binding unit. Other classes include benzopyrans and naphthalenes (eg, lasofoxifene). In this review article, I will discuss raloxifene and three new SERMs—arzoxifene, bazedoxifene, and lasofoxifene—that have been recently studied. I will discuss their effect on bone, breast, and the cardiovascular system, as well as on safety
South African Menopause Society revised consensus position statement on menopausal hormone therapy
The South African Menopause Society (SAMS) consensus position statement on menopausal hormone therapy (HT) 2014 is a revision of the SAMS Council consensus statement on menopausal HT published in the SAMJ in May 2007. Information presented in the previous statement has been re-evaluated and new evidence has been incorporated. While the recommendations pertaining to HT remain similar to those in the previous statement, the 2014 revision includes a wider range of clinical benefits for HT, the inclusion of non-hormonal alternatives such as selective serotonin reuptake inhibitors and serotonin noradrenaline reuptake inhibitors for the management of vasomotor symptoms, and an appraisal of bioidentical hormones and complementary medicines used for treatment of menopausal symptoms. New preparations that are likely to be more commonly used in the future are also mentioned. The revised statement emphasises that commencing HT during the 'therapeutic window of opportunity' maximises the benefit-to-risk profile of therapy in symptomatic menopausal women
Addressing the migration of health professionals: the role of working conditions and educational placements
This article provides a brief overview of the global health-worker shortage, which could undermine the Millennium Development Goal to halt and begin to reverse the spread of HIV/AIDS. The current situation suggests that long-term solutions to shortages can only be found by addressing the problem from a global perspective; that is, to eliminate shortages through substantial investments in training and retaining health workers in developed and developing countries, and not through policies that do not work towards solving this underlying problem, such as ones that restrict migration
An atomic scale mechanism for the antimalarial action of chloroquine from density functional theory calculations
Scalar and vector Slepian functions, spherical signal estimation and spectral analysis
It is a well-known fact that mathematical functions that are timelimited (or
spacelimited) cannot be simultaneously bandlimited (in frequency). Yet the
finite precision of measurement and computation unavoidably bandlimits our
observation and modeling scientific data, and we often only have access to, or
are only interested in, a study area that is temporally or spatially bounded.
In the geosciences we may be interested in spectrally modeling a time series
defined only on a certain interval, or we may want to characterize a specific
geographical area observed using an effectively bandlimited measurement device.
It is clear that analyzing and representing scientific data of this kind will
be facilitated if a basis of functions can be found that are "spatiospectrally"
concentrated, i.e. "localized" in both domains at the same time. Here, we give
a theoretical overview of one particular approach to this "concentration"
problem, as originally proposed for time series by Slepian and coworkers, in
the 1960s. We show how this framework leads to practical algorithms and
statistically performant methods for the analysis of signals and their power
spectra in one and two dimensions, and, particularly for applications in the
geosciences, for scalar and vectorial signals defined on the surface of a unit
sphere.Comment: Submitted to the 2nd Edition of the Handbook of Geomathematics,
edited by Willi Freeden, Zuhair M. Nashed and Thomas Sonar, and to be
published by Springer Verlag. This is a slightly modified but expanded
version of the paper arxiv:0909.5368 that appeared in the 1st Edition of the
Handbook, when it was called: Slepian functions and their use in signal
estimation and spectral analysi
Antibody-Mediated “Universal” Osteoclast Targeting Platform using Calcitonin as a Model Drug
Three monthly coral Sr/Ca records from the Chagos Archipelago covering the period of 1950-1995 A.D.: reproducibility and implications for quantitative reconstructions of sea surface temperature variations
In order to assess the fidelity of coral Sr/Ca for quantitative reconstructions of sea surface temperature variations, we have generated three monthly Sr/Ca time series from Porites corals from the lagoon of Peros Banhos (71°E, 5°S, Chagos Archipelago). We find that all three coral Sr/Ca time series are well correlated with instrumental records of sea surface temperature (SST) and air temperature. However, the intrinsic variance of the single-core Sr/Ca time series differs from core to core, limiting their use for quantitative estimates of past temperature variations. Averaging the single-core data improves the correlation with instrumental temperature (r > 0.7) and allows accurate estimates of interannual temperature variations (~0.35°C or better). All Sr/Ca time series indicate a shift towards warmer temperatures in the mid-1970s, which coincides with the most recent regime shift in the Pacific Ocean. However, the magnitude of the warming inferred from coral Sr/Ca differs from core to core and ranges from 0.26 to 0.75°C. The composite Sr/Ca record from Peros Banhos clearly captures the major climatic signals in the Indo-Pacific Ocean, i.e. the El Niño–southern oscillation and the Pacific decadal oscillation. Moreover, composite Sr/Ca is highly correlated with tropical mean temperatures (r = 0.7), suggesting that coral Sr/Ca time series from the tropical Indian Ocean will contribute to multi-proxy reconstructions of tropical mean temperatures
A randomized, observer-blinded immunogenicity trial of Cervarix(®) and Gardasil(®) Human Papillomavirus vaccines in 12-15 year old girls.
BACKGROUND: The current generation of Human Papillomavirus (HPV) vaccines, Cervarix® and Gardasil®, exhibit a high degree of efficacy in clinical trials against the two high-risk (HR) genotypes represented in the vaccines (HPV16 and HPV18). High levels of neutralizing antibodies are elicited against the vaccine types, consistent with preclinical data showing that neutralizing antibodies can mediate type-specific protection in the absence of other immune effectors. The vaccines also confer protection against some closely related non-vaccine HR HPV types, although the vaccines appear to differ in their degree of cross-protection. The mechanism of vaccine-induced cross-protection is unknown. This study sought to compare the breadth and magnitudes of neutralizing antibodies against non-vaccine types elicited by both vaccines and establish whether such antibodies could be detected in the genital secretions of vaccinated individuals. METHODS AND FINDINGS: Serum and genital samples were collected from 12-15 year old girls following vaccination with either Cervarix® (n = 96) or Gardasil® (n = 102) HPV vaccine. Serum-neutralizing antibody responses against non-vaccine HPV types were broader and of higher magnitude in the Cervarix®, compared to the Gardasil®, vaccinated individuals. Levels of neutralizing and binding antibodies in genital secretions were closely associated with those found in the serum (r = 0.869), with Cervarix® having a median 2.5 (inter-quartile range, 1.7-3.5) fold higher geometric mean HPV-specific IgG ratio in serum and genital samples than Gardasil® (p = 0.0047). There was a strong positive association between cross-neutralizing antibody seropositivity and available HPV vaccine trial efficacy data against non-vaccine types. CONCLUSIONS: These data demonstrate for the first time that cross-neutralizing antibodies can be detected at the genital site of infection and support the possibility that cross-neutralizing antibodies play a role in the cross-protection against HPV infection and disease that has been reported for the current HPV vaccines. TRIAL REGISTRATION: ClinicalTrials.gov NCT00956553
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