Age and growth of the Queen Mackerel (Scomberomorus plurilineatus) and Seventy-four (Polysteganus undulosus) of KwaZulu Natal, South Africa.

Thesis (M.Sc.)-University of Natal, 1996.This study provides information on the age and growth of two important Iinefish species, Scomberomorus pluriline~tus and Polysteganus undulosus. Age determination for both species was carried out using otoliths and growth was modelled using age- and length-based methods. For the age-based method various growth models were evaluated to determine which growth function best described the age-length data, whilst Shepherd's Length Composition Analysis was used to estimate growth parameters from length-frequency data. Preliminary stock assessments, based on limited catch data, were also attempted for both species. Age estimates for the pelagic migrant S. plurilineatus, derived from reading whole otoliths, ranged from 0 + to 6 + years. As validation by marginal increment analysis was inconclusive because of the seasonal occurrence of this species in KwaZulu-Natal waters, it was assumed that a single opaque band was laid down in the otolith annually. Reproducibility of age estimates evaluated using the average percentage error (APE) technique was good (9.4%). Von Bertalanffy growth parameters were poorly estimated from length-frequency data because multiple maxima were encountered on the fitting surface. However, from the age-length data, growth was adequately modelled by the von Bertalanffy growth equation: L t =9 3 5mmFL (l-e -0. 583yr-1 (t+o. 991yr) ) S. p!urilineatus are fully recruited to the fishery at the age of 1 + year and the ageiv at-50% maturity is 2 + years. Preliminary per-recruit analyses indicated that the spawner biomass of S. plurilineatus is at 50% of its unfished level. Polysteganus undulosus is an endemic, reef-dwelling sparid and large catches weremade earlier in the century. Age determination was carried out using sectioned otoliths collected in 1962 and 1963 before the collapse of the fishery. Age estimates ranged from 3 + to 20 + years. Marginal increment analysis indicated that active deposition of opaque bands occurred during winter but, because of the seasonal occurrence of P. undulosus in KwaZulu-Natal, validation was inconclusive. Reproducibility of the age estimates was low (APE = 18.2%) because of difficulties with band interpretation as a result of stacking on otolith margins in old fish. Von Bertalanffy growth parameters could not be adequately estimated from length frequency data because of the slow growth and longevity of this species. However, from the age-length data, no difference in growth rate between the sexes was observed, and growth for the combined sexes is described by the following logistic equation: L = 942mmTL t 1+e-O.277yr-l(t-S.178yrs) The age at full recruitment was found to be 12 + years and the age-at-50% maturity was 8.8 years. A preliminary stock assessment revealed that the spawner biomass of P. undulosus was already at 25% of its unfished level in the early 1960s

Persistence of Human Pathogens in a Crop Grown from Sewage Sludge Treated Soil

The advantages associated with the use of sewage sludge in agricultural land have motivated many countries to use sewage sludge for soil amendment purposes. South Africa’s deteriorated agricultural soil could benefit from this nutritional and cost effective product. However, the major shortcoming of sewage sludge is the presence of various pathogenic microorganisms. This raised concern amongst researchers with regard to public safety. The focus of this study, was to investigate the prevalence of pathogens in a crop grown in soil enriched with sewage sludge and to determine risk of infection thereof and to suggest appropriate management practice for sewage sludge use. Potato (Solanum tuberrosum), which is a high risk crop was used, to simulate a worst case scenario. Both the low metal sludge (LMS) and high metal sludge (HMS) were found to have associated diverse numbers of bacteria. Using culture-based technique, E.coli and Salmonella spp were found to persist in soil throughout the experimental period. One treatment option (LMS 16 tons/ha) showed a prevalence of these microorganisms in potatoes. Subsequent molecular studies based on amplification of 16S rRNA gene, yielded limited contamination of potatoes with enteric pathogens, however diverse types of opportunistic, pathogens (mostly environmental pathogens) were isolated from the potatoes. Enteric pathogens were isolated from the sewage treated soil in which these potatoes were grown. This study has indicated that growing even high risk crops, may lead to limited infestation of produce with primary pathogens. However, proper treatment of sewage sludge prior to use in agriculture is recommended to ensure public safety. The management requirements indicated in this study serve as recommended actions that can be implemented to ensure human safety with regard to sludge application to agricultural land.Thesis (PhD (Water Utilisation))--University of Pretoria, 2006.Chemical Engineeringunrestricte

Discordant calcium and parathyroid hormone with presumed epileptic seizures

A 33-year-old woman presented for the first time at the age of 9 years with recurrent seizures and was subsequently treated for epilepsy for 2 years. At 11 years of age, it was noted that the patient had hypocalcemia with an increased parathyroid hormone (PTH) measured with use of an intact PTH assay. Serum calcium was 5.73 mg/dL [1.43 mmol/L; reference interval (RI) 8.82–10.42 mg/dL (2.2–2.6 mmol/L)]; serum phosphate was 10.42 mg/dL [3.36 mmol/L; RI 1.86–4.34 mg/dL (0.6 –1.4 mmol/L)]; and PTH was 319.68 pg/mL [33.9 pmol/L; RI 8.49–68.84 pg/mL (0.9 –7.3 mmol/ L)]. Vitamin D (Total 25-OH; 25-OH D2 and D3) concentrations, magnesium concentrations, liver and renal function tests were all normal. No other endocrine abnormalities such as thyroid or gonadotropin resistance were detected. The patient also was of short stature and was overweight. However, she became overweight after the age of 13 years (body mass index at 13 years was 22.8 kg/m2), and the short stature was not significant, as she was at the lower end of the RI for height at 1.55 m. There was no cognitive impairment. Positive Chvostek sign was observed but not Trousseau sign.https://www.aacc.org/publications/clinical-chemistry2019-03-01am2018Chemical Patholog

A Case of Pantoea Endophthalmitis

A previously healthy 50-year-old man was transferred to our hospital for evaluation of acute inflammation in his right eye after ocular trauma while using a grass mower. Slit lamp examination showed 1 mm-length full thickness corneal laceration without leakage, 4+ cells and inflammatory membrane in the anterior chamber, 10% hypopyon, posterior synechiae formation, and cataract change. Upon orbital computerized tomography, a metallic intraocular foreign body in the lens was indentified. Vitrectomy, phacoemulsification, foreign body removal, anterior chamber irrigation, and intravitreal antibiotics injections of vancomycin and ceftazidime were performed. In a culture of humor from the anterior chamber grew Pantoea species. More procedures were performed, including intravitreal antibiotics injection of ceftazidime. Upon administering a course of intravenous ceftazidime, fortified ceftazidime and moxifloxacin eye drops, and oral prednisolone, the patient improved

Age and growth of Cape stumpnose Rhabdosargus holubi (Pisces: Sparidae) in the Eastern Cape, South Africa

Rhabdosargus holubi (Steindachner, 1881) is a small (maximum size = 450 mm total length; Heemstra and Heemstra 2004) sparid that is distributed along the south-east coast of Africa from St Helena Bay, South Africa, to Maputo, Mozambique (Götz and Cowley 2013). Spawning occurs in the nearshore marine environment primarily during winter, specifically May–August in KwaZulu-Natal (KZN) (Wallace 1975) and July–February in the South-Eastern Cape (Whitfield 1998). Individuals reach 50% sexual maturity at approximately 150 mm standard length (SL) in the Eastern Cape (Whitfield 1998). The early life stages are transported by the south-westward-flowing Agulhas Current, and recruit as post-flexion larvae and early juveniles into estuaries during late winter and early summer (Blaber 1974). The warm temperatures and high nutrient levels in estuaries favour fast growth (Blaber 1973a), and fish spend their first year of life in these environments, migrating back out to sea after reaching approximately 120 mm SL. Some individuals remain trapped in closed estuaries, where they may reach sizes greater than 200 mm SL (James et al. 2007a). Rhabdosargus holubi is the dominant estuarine-dependent marine teleost species recorded in permanently open and temporarily open/closed estuaries in the warm-temperate region, which spans the south, south-east and east coast of South Africa (Harrison 2005). The species is also an important component of the linefishery in many SouthAfrican estuaries (10–15.6% by number) (Pradervand and Baird 2002), particularly in Eastern Cape estuaries (Cowley et al. 2003). These figures underestimate the presence of R. holubi, as most individuals making use of estuaries are young, feeding predominately on filamentous macroalgae and diatom flora, and are generally too small to be caught with hook and line (De Wet and Marais 1990). James et al. (2007b) showed that R. holubi made up 34–92% of the annual seine-net catch in the East Kleinemonde Estuary. Rhabdosargus holubi is also important in the KZN shorebased linefishery, representing 4.6% of the total landed catch (Dunlop and Mann 2012)

Humoral hypercalcaemia in an infant : a diagnostic dilemma

Hypercalcaemia is seldom encountered in paediatric patients, and calcium levels are not routinely included in investigations. Associated symptoms such as nausea, vomiting, dehydration and abdominal pain are non-specific, thus sustained hypercalcaemia may result in delipidating calcifications, neurological and renal impairment. Physiologically, primary role players in calcium metabolism include parathyroid hormone (PTH) and vitamin D3 (calcitriol). It is important to establish whether hypercalcaemia is PTH or non-PTH related so that targeted treatment may be plannedhttp://jcp.bmj.comhj2021Chemical Patholog

Age, growth and retrospective stock assessment of an economically extinct sparid fish, Polysteganus undulosus, from South Africa

Age and growth of the endemic, reef-dwelling sparid, Polysteganus undulosus were determined by using archived otoliths collected in 1962 and 1963, before the fishery collapsed. Estimates of age ranged up to 20 years, but reproducibility of the age estimates was low because of stacking on the otolith margins in older fish. Validation of annual deposition of the opaque band indicated that active deposition occurred during late winter and spring. No difference in growth rate between the sexes was observed and the growth rate for the combined sexes was described by the following logistic equation: Lt = 942 mm TL/(1 + exp(-0.277 year-1 (t - 5.178 years))). The age-at-50% maturity was 8.8 years. A retrospective stock assessment revealed that, although in the early 1960s, the yield-per-recruit was optimal, the spawning biomass of P. undulosus was already at 25% of its unfished level. This study thus suggests that management strategies for slow-growing, long-lived, aggregating reef fishes should go beyond optimising yield alone and pay particular attention to the status of the spawning stock

Age and growth of the queen mackerel Scomberomorus plurilineatus from KwaZulu-Natal, South Africa

The age of the western Indian Ocean pelagic scombrid Scomberomorus plurilineatus was determined by counting rings in whole otoliths. Validation using marginal increment analysis was inconclusive and it was assumed that a single opaque band was laid down annually in the otolith of this species. The maximum observed age was six years. S. plurilineatus is fully recruited to the fishery at the age of one year and 50%-maturity is attained at the age of two years. For the-age-length data, the von Bertalanffy model was found to be the best fitting growth model. Growth was also estimated using a length-based method, Shepherd's Length Composition Analysis, but this proved to be inappropriate because of the seasonality of the catches of S. plurilineatus in KwaZulu-Natal. Based on a catch curve analysis, fishing mortality was estimated to be 0.28 yr-1. Preliminary per-recruit analyses revealed that spawner biomass of S. plurilineatus is currently reduced to 50% of its unfished level and it appears that the species is optimally exploited

Neonatal presentation of a child with Liddle syndrome, South Africa

DATA AVAILABILITY : Data supporting the findings of this study are available within the article.INTRODUCTION : Liddle syndrome is an autosomal dominantly inherited disorder usually arising from single mutations of the genes that encode for the alpha, beta and gamma epithelial sodium channel (ENaC) subunits. This leads to refractory hypertension, hypokalaemia, metabolic alkalosis, hyporeninaemia and hypoaldosteronism, through over-activation of the ENaC. CASE PRESENTATION : We describe a 5-day old neonate who presented with severe hypernatraemic dehydration requiring admission to Steve Biko Academic Hospital in South Africa in 2012. Further evaluation revealed features in keeping with Liddle syndrome. Two compound heterozygous mutations located at different subunits encoding the ENaC were detected following genetic sequencing done in 2020. The severe clinical phenotype observed here could be attributed to the synergistic effect of these known pathological mutations, but may also indicate that one of the other variants detected has hitherto undocumented pathological effects. MANAGEMENT AND OUTCOME : This child’s treatment course was complicated by poor adherence to therapy, requiring numerous admissions over the years. Adequate blood pressure control was achieved only after the addition of amiloride at the end of 2018, which raised the suspicion of an ENaC abnormality. CONCLUSION : To our knowledge, this is the first Liddle syndrome case where a combined effect from mutations resulted in severe disease. This highlights the importance of early recognition and management of this highly treatable genetic disease to prevent the grave sequelae associated with long-standing hypertension. Whole exome sequencing may assist in the detection of known mutations, but may also unveil new potentially pathological variants. WHAT THIS STUDY ADDS : This study highlights the importance of developing a high index of suspicion of tubulopathy such as Liddle syndrome for any child presenting with persistent hypertension associated with hypokalaemic metabolic alkalosis.http://www.ajlmonline.orgChemical PathologyPaediatrics and Child Healt