1,754 research outputs found
Heydrichia cerasina sp. nov. (Sporolithales, Corallinophycidae, Rhodophyta) from the southernmost tip of Africa. Phycologia, 51(1): 11- 21
A new species of Heydrichia (Sporolithales), H. cerasina sp. nov., is described, found only on pebbles in the low intertidal zone along a 10 km stretch of the South African south coast from Cape Agulhas to Struisbaai. The species is characterized by the following suite of features that distinguish it from the other two species of Heydrichia found in South Africa: 1) unusual cherry-red colour when freshly collected; 2) uniformly warty growth from; 3) relatively thin crust (to 1400 µm thick); 4) tetra/bisporangial sori comprised of mostly single sporangial chambers; and 5) unbranched spermatangial structures distributed on the floor, walls and roof of the mature male conceptacle. The species appears to be most closely related to H. homalopasta from Australia. This study has affirmed that the distribution of spermatangial structures within male chambers is a feature that cannot be used to separate Heydrichia from Sporolithon, the only other genus in Sporolithales, although features of thallus construction and tetra/bisporangia continue to distinguish the genera. A key to the southern African species from the order Sporolithales is provided.Web of Scienc
Atopic dermatitis: tacrolimus vs. topical corticosteroid use
Atopic dermatitis (AD), the dermatological manifestation of the atopic diathesis, has a variety of clinical presentations. It is a chronic and relapsing inflammatory disorder, requiring a multifaceted treatment approach. Topical corticosteroids are the backbone of therapy. However, concerns over adverse drug reactions associated with their long-term application limit their use. Tacrolimus, on the other hand, has been shown to be effective in stabilising the symptoms of AD in the long-term setting, without the side-effects that hamper the use of topical corticosteroids. Long-term safety data up to ten years are available in the literature. Despite this, the US Food and Drug Administration (FDA) black box warning of possible malignancies has resulted in much debate among experts. The main focus of this article is to compare the safety and efficacy of topical corticosteroids to calcineurin inhibitors, particularly tacrolimus. Furthermore, the aim is to evaluate the place of tacrolimus in AD therapy. A brief overview of the condition and other treatment modalities will also be discussed.Keywords: atopic dermatitis, tacroliums, topical corticosteroid us
The genus Phymatolithon (Hapalidiaceae, Corallinales, Rhodophyta) in South Africa, including species previously ascribed to Leptophytum
AbstractOf the genera within the coralline algal subfamily Melobesioideae, the genera Leptophytum Adey and Phymatolithon Foslie have probably been the most contentious in recent years. In recent publications, the name Leptophytum was used in quotation marks because South African taxa ascribed to this genus had not been formally transferred to another genus or reduced to synonymy. The status and generic disposition of those species (L. acervatum, L. ferox, L. foveatum) have remained unresolved ever since Düwel and Wegeberg (1996) determined from a study of relevant types and other specimens that Leptophytum Adey was a heterotypic synonym of Phymatolithon Foslie. Based on our study of numerous recently collected specimens and of published data on the relevant types, we have concluded that each of the above species previously ascribed to Leptophytum represents a distinct species of Phymatolithon, and that four species (incl. P. repandum) of Phymatolithon are currently known to occur in South Africa.Here we present detailed illustrated accounts of each of the four species, including: new data on male and female/carposporangial conceptacles; ecological and morphological/anatomical comparisons; and a review of the information on the various features used previously to separate Leptophytum and Phymatolithon. Southern African species ascribed to the genus Phymatolithon may be separated from one another in the field by their growth forms, the substrata on which they are generally found, and the colour of living thalli. A key for identifying southern African specimens in the field is included. Our data support the conclusion that the characters upon which Leptophytum is based are unreliable for generic delimitation from Phymatolithon
Translating metaphors into Afrikaans in a source language-oriented translation of the Hebrew Bible
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The impact of selected stakeholders on family business continuity and family harmony
The growth, survival and success of a family business are often influenced by issues relating to family relationships and family harmony. Not only do the actions of family members influence the success or failure of the family business, but so does the behaviour of non-family stakeholders. The success or failure of the family business may also have important emotional and financial ramifications for the different stakeholders involved in the business, whether that involvement is physical or emotional. Yet, very little is known about the impact that the various stakeholder groups have on the success of the family business, its continuity or the family harmony that prevails. Consequently, the primary objective of this study is to evaluate the impact of selected stakeholders, namely non-family members, inactive family members, the senior generation and the incumbent generation on the success of family businesses. Success, for the purposes of this study, was measured using two variables, family harmony and perceived future continuity. Respondents were identified by means of convenience sampling,and a total of 468 usable questionnaires were returned. The data collected were subjected to various statistical analyses. The validity of the measuring instrument was assessed by means of an exploratory factor analysis and reliability by calculating Cronbach’s alpha coefficients. The relationships proposed in the hypothesised model were assessed by means of structural equation modelling (SEM).The empirical results of this study reveal that family harmony influences the perceived future continuity of family businesses. In turn, inactive family members and the incumbent generation have a significant impact on the family harmony that exists in the family business.Key words: family business, inactive stakeholders, active stakeholders, continuity, family harmon
Semileptonic weak Hamiltonian to in momentum-space subtraction schemes
The CKM unitarity precision test of the Standard Model requires a systematic
treatment of electromagnetic and strong corrections for semi-leptonic decays.
Electromagnetic corrections require the renormalization of a semileptonic
four-fermion operator. In this work we calculate the
perturbative scheme conversion between the
scheme and several momentum-space subtraction schemes, which can
also be implemented on the lattice. We consider schemes defined by MOM and SMOM
kinematics and emphasize the importance of the choice of projector for each
scheme. The conventional projector, that has been used in the literature for
MOM kinematics, generates QCD corrections to the conversion factor that do not
vanish for and which generate an artificial dependence on the
lattice matching scale that would only disappear after summing all orders of
perturbation theory. This can be traced to the violation of a Ward identity
that holds in tha limit. We show how to remedy this by judicious
choices of projector, and prove that the Wilson coefficients in those schemes
are free from pure QCD contributions. The resulting Wilson coefficients (and
operator matrix elements) have greatly reduced scale dependence. Our choice of
the scheme over the traditional -mass scheme is motivated by
the fact that, besides being more tractable at higher orders, unlike the latter
it allows for a transparent separation of scales. We exploit this to obtain
renormalization-group-improved leading-log and next-to-leading-log strong
corrections to the electromagnetic contributions and study the (QED-induced)
dependence on the lattice matching scale.Comment: 1+22 page
Predicting the growth and feed intake of Boer goats in a feedlot system
This research sought to develop a mathematical model to predict the growth and feed intake of Boer goat kids destined for slaughter. Data were collected from castrated kids that were housed in individual pens and fed diets that varied in energy content (11.3, 12.0, and 12.7 MJ metabolizable energy (ME)/kg feed). Growth and feed intake were monitored weekly for 20 weeks, from the time that the kids weighed 22.2 ± 3.5 kg until they were slaughtered at 48.3 ± 0.8 kg. The linear equation (bodyweight = 0.202 age – 5.241 (R2 = 0.84)) was found to predict the growth of kids between 126 and 266 days old. Correlations between expressions of intake and bodyweight were evaluated, cumulative feed intake and bodyweight being most highly correlated (r = 0.93). Linear models were developed to predict cumulative feed intake from bodyweight for goats fed each diet. Regression coefficients were compared between diets, with the slope of the equation for goats on the low energy diet (6.74 ± 0.25) being greater than that of the medium (5.80 ± 0.23) and high energy diets (5.82 ± 0.23). This indicates that goats on the medium and high energy diets gained weight more efficiently than those on the low energy diet. The results from this study can be used by goat producers to predict the growth and intake of goats and determine the ideal feedlot finishing period for optimal productivity.______________________________________________________________________________________Keywords: cumulative intake, dietary energy, modellin
Beskrywing van tegnieke en chemiese analises van skaapliggame en foute daaraan verbonde
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Percutaneous endoscopic gastrostomy in children a 5-year experience
Introduction. Percutaneous endoscopic gastrostomy (PEG) has been performed on children since 1979. The indications for a PEG are wide ranging and while there are well-established benefits, it remains a procedure with recognised complications.Goals and objectives. The goal of this study was to review our experience with this procedure at a South African paediatric tertiary referral hospital over a 5-year period. The objectives were to review PEGs with regard to patient characteristics, indications, anaesthesia time required and complications.Methods. The study was a retrospective case record review.Results. A total of 70 PEGs were performed. Patients had a mean age of 4 years and 3 months, and a mean weight of 12.2 kg at the time of performing the procedure. The mean anaesthetic time required for performing a PEG was 27 minutes. Fifty-four PEGs (77%) were performed for inability to swallow, 15 (21 %) to improve caloric intake, and 1 (1 %) for continuous enteral feeding. There were no deaths, 5 patients had major complications (6%), and 12 patients (17%) needed antireflux surgery subsequent to the placement of a PEG.Discussion. There is an increasing demand for PEGs at our institution. The indications for a PEG in this series are similar to those reported in other series, although we may be underutilising PEGs to improve caloric intake. Our complication rates compare favourably with those reported in other series. We have, however, identified post-PEG gastro-oesophageal reflux disease as a complication we would like to reduce, and suggest a practical approach to do so
Quantifying the burden of the post-ICU syndrome in South Africa : a scoping review of evidence from the public health sector
BACKGROUND. The post-ICU syndrome (PICS) comprises unexpected impairments in physical, cognitive, and mental health after intensive care unit (ICU) discharge, and is associated with a diminished health-related quality of life (HRQOL). A Cochrane review recommended more research in this field from low- and middle-income countries. OBJECTIVE. This review aims to examine the extent and nature of publications in the field of PICS in the South African (SA) public health sector. Findings of available local research are contextualised through comparison with international data. METHODS. A comprehensive literature search strategy was employed. Inclusion criteria comprised publications enrolling adult patients following admission to SA public hospital ICUs, with the aim to study the main elements of PICS (ICU-acquired neuromuscular weakness, neurocognitive impairment, psychopathology and HRQOL). RESULTS. Three studies investigated physical impairment, 1 study psychopathology, and 2 studies HRQOL. Recommended assessment tools were utilised. High rates of attrition were reported. Neuromuscular weakness in shorter-stay patients had recovered at 3 months. Patients who were ventilated for ≥5 days were more likely to be impaired at 6 months. The study on psychopathology reported high morbidity. The HRQOL of survivors was diminished, particularly in patients ventilated for ≥5 days. CONCLUSION. This review found a paucity of literature evaluating PICS in the SA public health sector. The findings mirror those from international studies. Knowledge gaps pertaining to PICS in medical, surgical and HIV-positive patients in SA are evident. No publications on neurocognitive impairment or the co-occurrence of PICS elements were identified. There is considerable scope for further research in this field in SA.http://www.sajcc.org.zadm2022Critical Car
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