Growth and somatic production estimates of Dosinia hepatica (Lamark) (Mollusca: Bivalvia) in the Swartkops estuary, South Africa

Regular and quantitative sampling for Dosinia hepatica was performed in the Swartkops estuary over a period of a year. The size of the D. hepatica recorded at LWMST was significantly (P<0,01) larger than that sampled at 0,4 m above LWMST This appeared to be a result of a spatial separation of large and small individuals. Size frequency analyses of the populations sampled and growth ring lengths were used to construct a growth curve for D. hepatica. The calculated growth rate was slow, with D. hepatica reaching a shell length of approximately 16,3 mm and a dry tissue mass of ca. 44 mg after three years. The potential life span of the bivalve was estimated to be 8-9 years. The annual somatic production (per m2) of the population sampled was calculated to be 0,58 g shell free dry mass or 8,63 kJ, while the production biomass (P/B) ratio was 0,3

Die liberalisme en sy invloed in Suid-Afrika II

Die liberale rigting van die negentiende eeu was ’n wye wêreldbegewing wat in alle lande tot openbaring gekom het en sy invloed laat voel hetop elke terrein van die lewe. Veel van die koorsagtige bedrywigheid watdie geestelewe van die vorige eeu kenmerk, moet toegeskrywe word aandie besieling van die liberalisme wat tot elke lewenskring deurgedring hetmet ’n vaste program en ’n eie ideaal

Developing minimum clinical standards for physiotherapy in South African ICUs: A qualitative study

Rationale, aims, and objectives: Physiotherapists are integral members of the intensive care unit (ICU) team. Clinicians working in ICU are dependent on their own experience when making decisions regarding individual patient management thus resulting in variation in clinical practice. No formalized clinical practice guidelines or standards exist for the educational profile or scope of practice requirements for ICU physiotherapy. This study explored perceptions of physiotherapists on minimum clinical standards that ICU physiotherapists should adhere to for delivering safe, effective physiotherapy services to critically ill patients. Method: Experienced physiotherapists offering a service to South African ICUs were purposively sampled. Three focus group sessions were held in different parts of the country to ensure national participation. Each was audio recorded. The stimulus question posed was “What is the minimum standard of clinical practice needed by physiotherapists to ensure safe and independent practice in South African ICUs?” Three categories were explored, namely, knowledge, skill, and attributes. Themes and subthemes were developed using the codes identified. An inductive approach to data analysis was used to perform conventional content analysis. Results: Twenty-five physiotherapists participated in 1 of 3 focus group sessions. Mean years of ICU experience was 10.8 years (±7.0; range, 3-33). Three themes emerged from the data namely, integrated medical knowledge, multidisciplinary teamwork, and physiotherapy practice. Integrated medical knowledge related to anatomy and physiology, conditions that patients present with in ICU, the ICU environment, pathology and pathophysiology, and pharmacology. Multidisciplinary teamwork encompassed elements related to communication, continuous professional development, cultural sensitivity, documentation, ethics, professionalism, safety in ICU, and technology. Components related to physiotherapy practice included clinical reasoning, handling skills, interventions, and patient care. Conclusions: The information obtained will be used to inform the development of a list of standards to be presented to the wider national physiotherapy and ICU communities for further consensus-building activities

Growth, production and consumption of the thalassinid prawn Upogebia africana (Ortmann) in the Swartkops estuary

Populations of large and stunted Upogebia africana were regularly and quantitatively sampled in the Swartkops estuary. The growth of these prawns, determined by cohort analyses, was described by von Bertalanffy equations: Lt = 24,4 (1 – e−0,0583 (t + 1,8446) and Lt– 19,0 (1 – e−0,0454 (t + 4,0726) respectively, where Lt – carapace length (in mm) at age t (in months). Eggs were apparently laid after moulting, which occurred primarily during spring and summer. First sexual maturity was attained after 1,5 years, while the estimated life span was 4 years. The annual somatic production and Pg/B ratios of the populations sampled were 1864 and 1093 kJ.m-2 and 0,79 and 0,99 respectively. Somatic production of the entire estuarine population was approximately 1077 x 106 kJ.y−1. An estimated 13, 5 and 2% of this was ‘consumed’ by birds, fish and man respectively, while the remainder apparently entered the scavenger and detrital food webs

Variations in size compositions of populations of Upogebia africana (Ortmann) (Decapoda, Crustacea) within the Swartkops estuary and possible influencing factors

The size frequencies of various populations of the mud prawn Upogebia africana sampled within the Swartkops estuary were determined and the size compositions of these populations varied along the length of the estuary, as well as vertically within the intertidal zone. Ovigerous prawns were recorded from sites representing the extremes in population structures and their mean sizes differed significantly (P < 0,05) from each other. The variations in the size compositions were therefore attributed to differences in the growth of the prawns, rather than a spatial separation of adults and juveniles. The mean sizes of the adult prawns from the various stations were determined and plotted against factors such as water temperatures and salinities, nitrogen and organic contents of the substrata, population densities and distances of the populations from the estuarine mouth. The latter factor, which was used to give a relative measure of the exposure (in terms of duration and current velocity) of the populations to the flow of water entering the estuary during flood tides, gave the most significant (P < 0,01) correlation with the mean size of the adult prawns and could satisfactorily account for patterns observed

Mass mortality and recolonization of pyura stolonifera (heller) on the south coast of South Africa

A mass mortality of the ascidian Pyura stolonifera (red-bait) was recorded along the Tsitsikamma coast of South Africa in May 1991, following the infection of a large proportion of the population with a white microbialgrowth. At nine subtidal red-bait beds, reductions in percentage cover of red-bait were greatest on the crests of reefs (42 ± 17%:1SD) and lowest on the landward edges (17 ± 8%). The test of P. stolonifera appeared to be the main site of the microbial infection. Scanning electron and epifluorescent microscopy revealed much higher numbers of bacteria on the tests of infected individuals (64.3 ± 5.5 × 106·mm-2) compared to healthy ones (5.1 ± 0.1 × 106·mm-2). Fat, curved rod bacteria and thick chains, which accounted for more than 45% of the bacteria on infected red-bait tests, were absent from the tests of healthy red-bait. Standard characterization techniques, coupled with API tests, showed that the isolates from infected red-bait tests belonged exclusively to thegenus Vibrio, whereas isolates from healthy tests included the genera Vibrio, Pseudomonas, Aeromonas and Flavobacterium/Cytophaga. The mass mortality therefore appeared to be associated with the proliferation of large curved rod bacteria of the genus Vibrio. Recolonization by P. stolonifera into areas naturally denuded of red-bait was significantly faster than for experimental plots cleared of all organisms during the mid 1980s. A mean cover of 33 ± 4% was recorded for P. stolonifera after 38 months following natural mortality, whereas it took 71 months to achieve a comparable recovery of 35 ± 20% in experimental plots. Possible reasons for this difference (viz. substratum, recruitment and predation) are explored

The influence of acetaldehyde and water on the determination of 14C in wine alcohol

Der Einfluß von Acetaldehyd und Wasser auf die 14C-Bestimmung bei WeinalkoholDie Bestimmung von 14C im Äthanol von Wein wird nicht signifikant beeinflußt, wenn die Destillation sorgfältig durchgeführt wird und der Wasser- und Aldehydgehalt 10 % (v/v) bzw. 0,5 % (v/v) nicht übersteigt

The 14C content of the ethanol of South African wines ior the years 1925-1975

It has been shown that, due to atmospheric conditions, South African natural wines are lower in 14C content than their northern hemisphere counterparts for the periods of active nuclear explosion tests. On this basis it is incorrect to apply northern hemisphere 14C data to wines of the southern hemisphere.Der 14C-Gehalt des Äthanols südafrikanischer Weine der Jahrgänge 1925-1975Es konnte gezeigt werden, daß südafrikanische Naturweine infolge der atmosphärischen Bedingungen einen niedrigeren 14C-Gehalt besitzen, als ihn Vergleichsweine von der nördlichen Erdhalbkugel aus der Zeit der Kernwaffenversuche aufweisen. Es ist somit nicht gerechtfertigt, die 14C-Werte der Nordhemisphäre bei Weinen der südlichen Erdhalbkugel anzuwenden

Exploring linkages between drought and HIV treatment adherence in Africa: A Systematic Review

Climate change is directly and indirectly linked to human health, including through access to treatment and care. Our systematic review presents a ‘systems’ understanding of the nexus between drought and antiretroviral treatment (ART) adherence in HIV-positive individuals in the African setting. Narrative synthesis of 111 studies retrieved from Web of Science, PubMed/Medline, and PsycINFO suggests that economic and livelihoods conditions, comorbidities and ART regimens, human mobility, and psycho-behavioural dispositions and support systems interact in complex ways in the drought-ART adherence nexus in Africa. Economic and livelihood-related challenges appear to impose the strongest impact on human interactions, actions and systems that culminate in non-adherence. Indeed, the complex pathways identified by our systems approach emphasise the need for more integrated research approaches to understanding this phenomenon and develop interventions