1,832 research outputs found
POPULATION DYNAMICS OF THE WANDERING ALBATROSS DIOMEDEA EXULANS AT MARION ISLAND: LONGLINE FISHING AND ENVIRONMENTAL INFLUENCES
The subantarctic Prince Edward Islands (Marion and Prince Edward) support the largest breeding population of the Vulnerable wandering albatross Diomedea exulans. The number of birds breeding at Marion Island has fluctuated over the past three decades apparently as a result of both real changes in the size of the population and changes in the proportion of the population that attempts to breed in a given year. Changes in several demographic parameters that appear to be influenced by both environmental and anthropogenic effects are described. From 1994–2001, the proportion of first-time breeders in the population was positively correlated with the maximum ENSO (Niño 3) index, whereas from 1984–2000 the annual survival rates of breeding adults were negatively correlated with Japanese pelagic longline fishing effort in the southern Indian Ocean. Adult survival rates were significantly correlated with those on neighbouring Possession Island, Crozet Islands, but differed from those at South Georgia, suggesting common factors operating at an ocean-basin scale. The average survival rate of adult females was lower than that of males. Males who lost partners took 40% longer than females to find a new mate, suggesting a male-biased population. Survival rates of juvenile males and females did not differ. The age distribution of first-time breeders shifted progressively towards younger birds during the 1990s. Higher than expected survival rates of breeding adults during the late 1990s may be linked to large amounts of supplementary food being made available by the initiation of a longline fishery for Patagonian toothfish Dissostichus eleginoides close to the islands at this time. Overall, breeding success was better than recorded at other localities, indicating that breeding conditions at Marion Island were comparatively favourable. The early implementation of both international and national conservation initiatives to reduce the impact of longline fishing on this species and improve its conservation status is encouraged.Afr. J. mar. Sci. 25: 503–51
Risk factors for atherosclerosis - can they be used to identify the patient with multisystem atherosclerosis?
Risk factors are often used in preventive care programmes to identify the patient at particular risk for developing atherosclerosis. Risk factors for atherosclerosis have also been shown to be linked to the presence of the disease at a given time, a fact that may be helpful when screening for additional atherosclerotic disease in the known arteriopath. Risk factors .were recorded in 471 patients admi"ed to hospital with symptoms of atherosclerosis. In patients admi"ed primarily with peripheral vascular disease, risk factors linked to the presence of additional coronary artery disease were a family history of ischaemic heart disease (odds ratio = 2,6), the presence of carotid artery disease (odds ratio = 1,9) and high fasting serum triglyceride levels (P < 0,04). Grouping these factors together usin.g logistic regression, ischaemic heart disease could be predicted with a sensitivity of 72% and a specificity of 43%. Patients admitted with carotid artery disease were more likely to have ischaemic heart disease in the presence of peripheral vascular disease (odds ratio = 1,9) and a raised serum cholesterol level (P < 0,02), while female gender (odds ratio = 2,9) and an increase in age (P< 0,001) were linked to an increased prevalence of concomitant atherosclerosis in patients admmed with acute myocardial infarction or for elective coronary artery bypass surgery. Using an age cut-off point, additional atherosclerosis could be predicted with a sensitivity of 32% and a specificity of 88% in these patients
Identification of polymer-based artefacts from the former Wheeler Residence at the Mernda archaeological site in Victoria, Australia: a comparison of attenuated total reflectance and reflectance spectroscopic techniques
Determination of glomerular filtration rate with radionuclide renography and direct urinary activity quantitation
Objective. The direct urinary activity quantitation method is quick (approximately 40 minutes), requires only a single blood sample, is performed as part of standard renal scanning and shows high accuracy compared With 24hour creatinine clearance. The purpose was to evaluate the practical application and accuracy of this technique at our clinic. Design. Direct urinary activity quantitation was done in patients scheduled for routine radionuclide renography and compared to standard multiple-blood-sample techniques by means of Cr-51-EDTA and Tc-99m-DTPA.Setting. Academic Medical Complex, Department of Nuclear Medicine, Universitas Hospital, Bloemfontein.Participants. Fifteen patients scheduled for routine radionuclide renography (glomerular filtration rate (GFR) determination) were voluntarily enrolled in the study. The GFRs of selected patients varied over a wide range. Possible obstructive uropathy was excluded.Main outcome measures. GFRs obtained by the direct urinary method were compared with GFRs determined by multisample Cr-51-EDTA and Tc-99m DTPA.Results. GFRs from the direct urinary method compared with multisample Tc-99m-DTPA showed differences from -19,85 to 22,95 ml/min with a mean of 0,2 (+- 12,25) ml/min (r = 0,93). When compared with multisample Cr-51 EDTA, differences ranged from -34,35 to 21,05 ml/min with a mean of -4,25 (+- 16,08) ml/min (r =0,90).Conclusion. The direct urinary activity technique is easily applied and highly accurate compared with previous standardised multisample radionuclide techniques for determination of GFR
Non-steroidal anti-inflammatory drugs(NSAIDs) and physiotherapy - a selective review
This paper presents a selective review on the non-steroidal anti-inflammatory drugs (NSAIDs). These drugs,which form the mainstay of treatment of a variety of musculoskeletal and rheumatic conditions, may facilitate the efficacy of and compliance with physiotherapy treatment. Their mechanisms of action, adverse effects, various routes of administration, eg systemic versus topical, and the role that these drugs may play in physiotherapy practice are discussed
Saving on household electric water heating : what works best and by how much?
CITATION: Nel, P. J. C., Booysen, M. J. & Van Der Merwe, B. Saving on household electric water heating : what works best and by how much?. In IEEE Innovative Smart Grid Technologies - Asia (ISGT-Asia), 4-7 December 2017, Auckland, New Zealand, doi:10.1109/ISGT-Asia.2017.8378439.The original publication is available at https://ieeexplore.ieee.orgElectric heating of water for domestic use is a substantial component of total household energy costs. Thermal energy in a water heater is either used (as warm water) or lost to the environment. Various approaches to reduce the losses and improve the efficiency of these notoriously inefficient and costly water heaters have been proposed and are employed. However, given the complex factors at play, making sense of the savings approaches and choosing the right one for the right use case is not a simple task and often misunderstood. This paper addresses this problem by comparing some of the commonly employed approaches, including schedule control, change in set temperature, use of thermal insulation, and reduction in consumed volume. We also compare the impact of environmental factors, such as changing the ambient temperature around the water heater and the cold inlet temperature. The results show that for the consumption profiles and use cases evaluated, schedule control is the most effective, followed by insulation of the tank and piping. Combined, these two interventions save up to 25%. We also find that the effect of the temperature of the cold inlet water dwarfs that of the ambient temperature, is in line with other approaches, and means the installation status quo needs to be reconsidered.https://ieeexplore.ieee.org/document/8378439/Preprin
Alcohol marketing and adolescent alcohol consumption: Results from the International Alcohol Control study South Africa
Background. A complete ban on alcohol advertisements has been proposed for South Africa (SA), but there has been limited local research on the association between exposure to alcohol advertisements and alcohol consumption.Objectives. To examine the role of demographic factors, exposure to alcohol marketing and liking of alcohol advertisements in predicting use of alcohol in the past 6 months among older adolescents in Tshwane, Gauteng Province, SA.Methods. Participants comprised the adolescent sub-sample (N=869) of the International Alcohol Control study survey that was conducted in SA. They consisted of 408 males and 461 females aged 16 and 17 years who took part in structured interviews on their alcohol consumption and various alcohol-related attitudes and behaviours. A multiple survey logistic regression analysis of the dependent variable alcohol use in the past 6 months on the independent variables age, gender, educational status, socioeconomic status, exposure to alcohol brand marketing and liking of alcohol advertisements was used. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated.Results. The prevalence of drinking in the past 6 months was 10.6% (95% CI 5.9 - 18.3). The number of modes of alcohol brand/product advertising to which the adolescents were exposed was positively associated with alcohol use in the past 6 months. An additional mode of alcohol brand/product advertising exposure led to a relative increase of 1.13 (95% CI 1.01 - 1.28) in the odds of alcohol use in the past 6 months (e.g. a participant who was exposed to advertisements via seven different channels was 2.08 times more likely to have used alcohol in the past 6 months than a participant with exposure via a single channel). Having a strong dislike of alcohol advertisements was associated negatively (protective) with alcohol use in the past 6 months, with the odds ratio being 0.35 (95% CI 0.19 - 0.64). Having only a moderate dislike or a liking of alcohol advertisements was positively associated with alcohol use in the past 6 months among the study participants (OR 2.90 and 2.84, respectively). Age, gender, educational status and socioeconomic status were not independently associated with alcohol consumption.Conclusions. Exposure to alcohol marketing and not being strongly averse to advertisements of alcohol brands and products were associated with alcohol use among adolescents. The results have implications for policies on alcohol marketing in SA.Ă‚
Southern African HIV Clinicians Society guideline for the prevention, diagnosis and management of cryptococcal disease among HIV-infected persons: 2019 update.
Very High-Energy Gamma-Ray Observations of PSR B1509-58 with the CANGAROO 3.8m Telescope
The gamma-ray pulsar PSR B1509-58 and its surrounding nebulae have been
observed with the CANGAROO 3.8m imaging atmospheric Cherenkov telescope. The
observations were performed from 1996 to 1998 in Woomera, South Australia,
under different instrumental conditions with estimated threshold energies of
4.5 TeV (1996), 1.9 TeV (1997) and 2.5 TeV (1998) at zenith angles of ~30 deg.
Although no strong evidence of the gamma-ray emission was found, the lowest
energy threshold data of 1997 showed a marginal excess of gamma-ray--like
events at the 4.1 sigma significance level. The corresponding gamma-ray flux is
calculated to be (2.9 +/- 0.7) * 10^{-12}cm^{-2}s^{-1} above 1.9 TeV. The
observations of 1996 and 1998 yielded only upper limits (99.5% confidence
level) of 1.9 * 10^{-12}cm^{-2}s^{-1} above 4.5 TeV and 2.0 *
10^{-12}cm^{-2}s^{-1} above 2.5 TeV, respectively. Assuming that the 1997
excess is due to Very High-Energy (VHE) gamma-ray emission from the pulsar
nebula, our result, when combined with the X-ray observations, leads to a value
of the magnetic field strength ~5 micro G. This is consistent with the
equipartition value previously estimated in the X-ray nebula surrounding the
pulsar. No significant periodicity at the 150ms pulsar period has been found in
any of the three years' data. The flux upper limits set from our observations
are one order of magnitude below previously reported detections of pulsed TeV
emission.Comment: Accepted to publication in Astrophys. Journal, 25 pages, 2 figure
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