Carbon isotope ratios of Sterkfontein fossils indicate a marked shift to open environments c.1.7 Myr ago

Sterkfontein straddles a period in the Plio-Pleistocene in which the effects of global-scale climate shifts on continental environments and biota are not yet well understood. Reconstructions based on faunal indicators have suggested incremental shifts from relatively closed, mesic landscapes to open, arid environments at this time. We examined environmental shifts from ~2.5 to 1.7 million years ago (Myr) using a C3 / C4 index derived from 13C / 12C data on bovid fossils from Sterkfontein. Data for Member 4 and the Member 5 East infill indicate persistence of a wooded to moderately wooded environment until about 2.0-1.8 Myr. Data indicating a marked shift to open environments are observed only for the younger Member 5 West infill. We conclude that the major shift to open environments occurred near 1.7 Myr rather than at c. 2.5 Myr

Clinical presentation of chronic-non-infectious rhinitis in children

No Abstract

The rational usage of Drimia robusta Bak. in traditional medicine

Drimia robusta was screened for biological activity using an antibacterial, the cyclooxygenase, and the angiotensin-converting enzyme assays. Ethanolic bulb extracts exhibited anti-inflammatory activity Antibacterial activity was present in the ethyl acetate bulb extract. A phytochemical screening of D. robusta for alkaloids, saponins and cardiac glycosides was carried out. D. robusta does not contain alkaloids. Bulb and leaf extracts exhibited haemolytic activity, which is characteristic of saponins. The bulb contains 2-deoxy sugars, common components in the sugar moieties of cardiac glycosides. Chromatographic screening showed that the bulbs do not contain cardenolides Bufadienolides were detected, one of which was identified as proscillaridin A

The social psychology of citizenship: engagement with citizenship studies and future research

In this article we review the argument outlined in the opening article in this special thematic section: that the current social psychology of citizenship can be understood as the development of longstanding conceptualisations of the concept within the discipline. These conceptualisations have contributed to the current social psychological study of the constructive, active and collective (but often exclusive) understandings of citizenship in people’s everyday lives, as evidenced by contributions to this thematic section. We consider how this emerging body of work might fit with current citizenship studies and in particular how it may contribute to the current trend towards conceiving citizenship as an active practice embedded in everyday social life. Specifically, we highlight three areas of future research that we think are particularly promising: citizenship and recognition; displays and enactments of citizenship in public space; citizenship and lived coexistence. Although this is far from an exhaustive list of possibilities, we propose that research in these areas could enable the way for social psychology to articulate a distinct, recognisable and valuable contribution to citizenship studies

Survival of bifidobacteria and their usefulness in faecal source tracking

Bifidobacteria have long since been recommended as indicators of human and animal pollution. Concentration ratio (tracking ratio) of the sorbitol-utilising bifidobacteria (SUB) and the total bifidobacteria (TB) can be used to distinguish between animal and human sources of faecal water contamination. The cut-off value needs to be calibrated in a given geographical area. Seven sites with permanent faecal contamination were selected in South Africa. Concentrations of SUB ranged from 10-50000 cells/100 mL, while TB ranged from 0-8000 cells/100 mL. The tracking ratio ranged from 0.10 to 6.25, but no clear cut-off value could be established. The YN-17 agar was replaced for TB with the modified Beerens medium with pH = 5.70, to suppress the growth of faecal streptococci. Tracking ratios observed are most likely the results of different survival rates of SUB and TB. Bifidobacteria die-off due to nutrients was not found to be significant using design of experiment. Thus a lack of continuous input or oxygen levels in water may be major factors. This would limit the ratios used as a faecal source tracking method

Child suicide rates during the COVID-19 pandemic in England

BACKGROUND: There is concern about the impact of COVID-19, and the control measures to prevent the spread, on children's mental health. The aim of this work was to identify if there had been a rise of childhood suicide during the COVID pandemic. METHOD: Using data from England's National Child Mortality Database (NCMD) the characteristics and rates of children dying of suicide between April to December 2020 were compared with those in 2019. In a subset (1(st) January to 17(th) May 2020) further characteristics and possible contributing factors were obtained. RESULTS: A total of 193 likely childhood deaths by suicide were reported. There was no evidence overall suicide deaths were higher in 2020 than 2019 (RR 1.09 (0.80-1.48), p=0.584) but weak evidence that the rate in the first lockdown period (April to May 2020) was higher than the corresponding period in 2019 (RR 1.56 (0.86-2.81), p=0.144). Characteristics of individuals were similar between periods. Social restrictions (e.g. to education), disruption to care and support services, tensions at home and isolation appeared to be contributing factors. LIMITATIONS: As child suicides are fortunately rare, the analysis is based on small numbers of deaths with limited statistical power to detect anything but major increases in incidence. CONCLUSION: We found no consistent evidence that child suicide deaths increased during the COVID-19 pandemic although there was a possibility that they may have increased during the first UK lockdown. A similar peak was not seen during the following months, or the second lockdown

Scaling Observation Error for Optimal Assimilation of CCI SST Data into a Regional HYCOM EnOI System

South Africa currently possesses no operational ocean forecasting system for the purpose of predicting ocean state variables including temperature,salinity and velocity. Substantial initial efforts towards this goal have been made and resulted in a system using a regional Hybrid Coordinate Ocean Model (HYCOM) along with the Ensemble Optimal Interpolation (EnOI)assimilation scheme. Assimilating only sea surface temperature (SST) observations from the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) product into the system resulted in a degraded forecast. Aiming to address this, Climate Change Initiative (CCI) SSTs are assimilated into the system in an effort to improve the forecast skill. Observation errors in the assimilated product are used in the EnOI to determine whether more confidence should be placed in the model or observations in producing the analysis, but overconfidence in observations can shock the model and result in failure. To tweak the impact of the assimilation, a scaling factor is applied in the assimilation code. A scaling factor of 25 was found to produce a favourable result with lowest mean root mean square error (RMSE;1.098C) between the model and observations over time. Postulating the error to be overconfident, a floor value is introduced in order to set a minimum value for the observation error thereby reducing confidence in the observations. These experiments fared less favourably with a floor value of 0.5 and a scaling factor of 15 producing the best mean RMSE (1.118C)

Neonatal cardiomyopathy and lactic acidosis responsive to thiamine

A congestive cardiomyopathy was diagnosed in a girl at the age of 4 weeks. In the weeks following she developed general muscle hypotonia and plasma lactate increased to 8.5 mmol/L. Biochemical investigations of a muscle biopsy at the age of 3 months showed a deficiency in the oxidation of all substrates tested: pyruvate plus malate, 2-ketoglutarate and palmitate plus malate. After freezing and thawing of the homogenate and the addition of essential cofactors, the oxidation of the ketoacids normalized. The oxidation defect in the untreated homogenate can be explained by a deficiency in one of the cofactors (such as thiamine pyrophosphate, NAD+ or CoASH), or by a defect in the oxidative phosphorylation. Treatment with thiamine and carnitine resulted in a decrease in blood lactate to normal levels and a dramatic clinical improvement. Suspension of thiamine caused deterioration of her clinical condition and lactic acidaemia. The thiamine therapy was then continued. The girl is now 6 years old and in perfect health