1,670 research outputs found
Bridging the transactional gap in Open Distance Learning (ODL): The case of the University of South Africa (Unisa)
The aim of this paper is to map and audit the availability and use of e-learning resources by Communication Science students at the University of South Africa (UNISA), in order to ensure that they provide a seamless learning experience to bridge the transactional distance in its Open Distance Learning (ODL) context. The Communication Science students targeted were COMSA executives and Unisa Radio employees. To serve the goal of the paper the following specific objectives were formulated: to establish types of e-learning resources available at Unisa, and to identify the benefits of elearning at Unisa. This study is informed by Michael Moore’s Transactional Distance theory. This theory, which focuses on dialogue, transactional distance and telecommunication systems, has been widely applied in many similar studies. A survey research design was used whereby questionnaires were administered to all COMSA executives and 50% of Unisa Radio student employees who were chosen using simple random sampling. The data gathered was analysed using thematic categorisation and tabulation and the findings were presented descriptively. The findings indicate that Unisa provides a variety of e-learning resources for its students. In addition, computers and the internet are most useful to students’ studies. It should be mentioned that e-learning facilitates and opens avenues for effective teaching. This study focused only on the availability and use of e-learning by Communication Science students at Unisa. Therefore, it will be necessary for a broader study to be undertaken which will focus on academic and ICT staff as well as students chosen across the Unisa community.
Keywords: Open Distance Learning; E-learning; Online education; ICTs in teaching and learning, University of South Afric
The impact of a modified World Health Organization surgical safety checklist on maternal outcomes in a South African setting: A stratified cluster-randomised controlled trial
Background. In South Africa (SA), the Saving Mothers Reports have shown an alarming increase in deaths during or after caesarean delivery.Objective. To improve maternal surgical safety in KwaZulu-Natal Province, SA, by implementing the modified World Health Organization surgical safety checklist for maternity care (MSSCL) in maternity operating theatres.Methods. The study was a stratified cluster-randomised controlled trial conducted from March to November 2013. Study sites were 18 hospitals offering maternal surgical services in the public health sector. Patients requiring maternal surgical intervention at the study sites were included. Pre-intervention surgical outcomes were assessed. Training of healthcare personnel took place over 1 month, after which the MSSCL was implemented. Post-intervention surgical outcomes were assessed and compared with the pre-intervention findings and the control arm. The main outcome measure was the mean incidence rate ratios (IRRs) of adverse incidents associated with surgery.Results. Significant improvements in the adverse incident rate per 1 000 procedures occurred with combined outcomes (IRR 0.805, 95% confidence interval (CI) 0.706 - 0.917), postoperative sepsis (IRR 0.619, 95% CI 0.451 - 0.849), referral to higher levels of care (IRR 1.409, 95% CI 1.066 - 1.862) and unscheduled return to the operating theatre (IRR 0.719, 95% CI 0.574 - 0.899) in the intervention arm. Subgroup analysis based on the quality of implementation demonstrated greater reductions in maternal mortality in hospitals that were good implementers of the MSSCL.Conclusions. Incorporation of the MSSCL into routine surgical practice has now been recommended for all public sector hospitals in SA, and emphasis should be placed on improving the quality of implementation
The effects of HIV/AIDS on the clinical profile and outcomes post pericardiectomy of patients with constrictive pericarditis: a retrospective review.
OBJECTIVE: The clinical profile and surgical outcomes of patients with constrictive pericarditis were compared in HIV-positive and -negative individuals. METHODS: This study was a retrospective analysis of patients diagnosed with constrictive pericarditis at Inkosi Albert Luthuli Central Hospital, Durban, over a 10-year period (2004-2014). RESULTS: Of 83 patients with constrictive pericarditis, 32 (38.1%) were HIV positive. Except for pericardial calcification, which was more common in HIV-negative subjects (n = 15, 29.4% vs n = 2, 6.3%; p = 0.011), the clinical profile was similar in the two groups. Fourteen patients died preoperatively (16.9%) and three died peri-operatively (5.8%). On multivariable analysis, age (OR 1.17; 95% CI: 1.03-1.34; p = 0.02), serum albumin level (OR 0.63; 95% CI: 0.43-0.92; p = 0.016), gamma glutamyl transferase level (OR 0.97; 95% CI: 0.94-0.1.0; p = 0.034) and pulmonary artery pressure (OR 1.49; 95% CI: 1.07-2.08; p = 0.018) emerged as independent predictors of pre-operative mortality rate. Peri-operative complications occurred more frequently in HIV-positive patients [9 (45%) vs 6 (17.6%); p = 0.030]. CONCLUSIONS: Without surgery, tuberculous constrictive pericarditis was associated with a high mortality rate. Although peri-operative complications occurred more frequently, surgery was not associated with increased mortality rates in HIV-positive subjects
Maternal serum fructosamine values after delivery of macrosomic babies and unexplained stillbirths
Measurement of serum fructosamine and haemoglobin A, levels and glucose tolerance tests were performed in 75 women in the immediate postpartum period. None had predisposing factors to gestational diabetes. They were divided into three groups: group I consisted of 15 women who delivered an unexplained stillbirth; group 11 of 30 women who gave birth to babies weighing between 2500 g and 3900 g at term; and group III of 30 women who delivered babies weighing≥ 4000 g. There was a significant difference in the mean level of serum fructosamine between the unexplained stillbirth and control groups (P < 0,001). Although the HbA, values varied in the three groups, there was a significant difference between the unexplained stillbirth group and the macrosomic infant group (P < 0,05). All patients had normal glucose tolerance tests
Mastering your fellowship
The series, “Mastering your Fellowship”, provides examples of the question format encountered in the written examination, Part A of the FCFP(SA) examination. The series aims to help Family Medicine registrars prepare for this examination. Model answers are available online.Keywords: FCFP(SA) examination, Family Medicine registrar
The supramolecular chemistry of novel synthetic biomacromolecular assemblies
Dissertation (PhD)--Stellenbosch University, 2004ENGLISH ABSTRACT: Over the past decade peptide bola-amphiphiles have been the subject of much attention
because of their role as potential models of functionalised membranes and as new
generation surfactants. In the quest for new surfactants a peptidomimetic-based approach
was used to design a library of novel 'hybrid' bola-amphiphilic peptide surfactants
derived from sapecin B and a model symmetrical oligo-glycine bola-amphiphile. The
library was divided into different series, each one purpose-built; first, to investigate
hierarchal supramolecular architecture and, second, to investigate potential antimicrobial
activity. The bola-amphiphiles were synthesised using Fmoc-polyamide based solid phase
peptide synthesis and purified via high performance liquid chromatography. The peptide
hybrids were characterised using electro spray mass spectrometry, nuclear magnetic
resonance, different modes of electron microscopy, Fourier-transform infrared
spectroscopy and, in some cases, further studies were done using circular dichroism and
bioactivity tests.
The model bola-amphiphile suberamide(GGh was synthesised using peptide fragment
condensation based on solid phase peptide synthesis. The synthesis is bi-directional
(N~C and C~N) and versatile, making it possible to synthesis new dicarboxylic
oligopeptide bola-amphiphiles and other analogous compounds. The product,
suberarnide(GG)2, was purified using its inherent ability to self-assemble in an acidic
solution.
Novel asymmetrical bola-amphiphiles composed of dipeptide head groups linked via an
aliphatic (I)-amino acid, serving as a hydrocarbon spacer, were also synthesized. Two
small libraries of bola-amphiphiles were established - the first involved variation in
to-amino acid length and the other variation in the C-terminal amino acid. The bolaamphiphiles
were self-assembled in either 0.1% trif1uoroacetic acid or 0.1%
triethylamine. Electron microscopy revealed the formation of a variety of higher order
supramolecular architectures based on ~-sheet self-assembly. FT-IR spectrometry
indicated that interlayer and intralayer hydrogen bond networks, together with strong selfassociation,
promoted by the hydrophobic effect and, in certain instances, electrostatic
interactions, are responsible for the variety of supramolecular architectures. Variations in the higher order structures can be attributed to amino acid composition, specifically
length of m-amino acid, nature of the C-terminal amino acid and the optimised solvent
conditions used for the self-assembly process.
A third library of novel 'hybrid' bola-amphiphilic peptide surfactants, in which a cationic
tripeptide motif from antimicrobial peptides was combined in a hybrid molecule
containing a oi-amino acid residue, was established. These bola-amphiphiles displayed
potent antimicrobial activity against both Gram-positive and Gram-negative bacteria; the
analogues were as active or more active than the leader peptides yet, remarkably,
displayed little or no appreciable haemolytic activity. These organopeptide bolaamphiphiles
thus demonstrated selective toxicity towards bacteria. The hydrophobicity
imparted by the co-amino acid has contrasting effects on haemolysis and antimicrobial
activity of the peptide analogues. The other unique feature of these peptides and their
analogues is the fact they self-assembled into complex supramolecular architectures,
composed primarily of ~-sheets. Their self-assembly is primarily governed by
hydrophobic interactions together with inter and intralayer hydrogen bonding. Electron
microscopy clearly revealed higher order structures for both peptides and analogues. The
generation of higher order supramolecular architecture is dependent on optimisation of ~-
sheet self-assembly whereas antimicrobial activity is dependent on the balance between
net positive charge and optimum hydrophobicity of the peptide hybrids.
This study has demonstrated that it is possible to design hybrid peptide surfactants
capable of producing higher order supramolecular architecture and improving the
antimicrobial activity whilst reducing the haemolytic effect. The study and design of
these versatile 'purpose-built' bio-inspired surfactants heralds a novel approach, one that
shows tremendous potential.AFRIKAANSE OPSOMMING: Die afgelope dekade het bola-amfifiliese peptiede baie aandag geniet weens hulle rolle as
potensiële modelle van gefunksionaliseerde membrane en as 'n nuwe generasie
surfaktante. In die soeke na nuwe surfaktante is 'n peptiedornimetiese benadering gevolg
om 'n biblioteek van nuwe "hibried" bola-amfifiliese peptiedsurfaktante van sapesien B
en 'n simmetriese oligoglisien bola-amfifil af te lei. Die biblioteek is in verskillende
reekse onderverdeel. Elke reeks is doelmatig vervaardig om ondersoek in te stel na twee
aspekte, nl. die rangorde van die supramolekulêre strukture en die potensiële
antirnikrobiese aktiwiteit. Fmoc-poliamied gebaseerde soliedefase-peptied-sin-tese is
aangewend vir die sintese van die bola-amfifile en hulle is met behulp van hoë
doeltreffendheid vloeistofchromatografie gesuiwer. Die peptiedhibriede is gekarakteriseer
met behulp van elekrosproei massaspektrometrie, kern-magnetiese resonansie,
verskillende modusse elektronrnikroskopie, Fourier-transform infrarooispektrometrie en,
in sommige gevalle is verdere studies met sirkulêre dichroïsme en bioaktiwiteitstoetsing
uitgevoer.
Die bola-amfifilsuberamiedtflfij--model is met behulp van peptiedfragment-konden-sasie
gesintetiseer gegrond op soliedefase-peptiedsintese. Dit sintese vind in twee rigtings plaas
(N~C en C~N) en is veelsydig aangesien dit die sintese van sowel nuwe dikar-boksielbola-
amfifile as ander analoë verbindings moontlik maak. Die produk, suber-arnied(GG)2,
is gesuiwer met behulp van die verbinding se inherente vermoë tot self-montering in suur
oplossings.
Nuwe assimetriese bola-amfifile, saamgestel uit dipeptiedkopgroepe, gekoppel via 'n
alifatiese ro-aminosuur, wat as koolwaterstofspasieerder dien, is ook gesintetiseer. Twee
klein bola-amfifilbiblioteke is saamgestel - die een het variasies in die ro-aminosuur se
lengte omvat en die ander een variasies in die C-terrninale aminosuur. Selfmontering van
die bola-amfifile het plaasgevind in of 0,1 % trifluorasynsuur Of 0,1 % trietielamien.
Elektronrnikroskopie het die bestaan van 'n verskeidenheid hoërorde supramolekulêre
strukture, gegrond op p-plaatselfmontering, aangetoon. Uit FT-IR-spektrometrie blyk dit
dat inter - en intralaag waterstofbinbdingsnetwerke en sterk selfassosiasie, 19. word
bevorder deur die hidrofobiese effek en, in sekere gevalle, elektrostatiese interaksies, is
verantwoordelik vir die verskeidenheid supramolekulêre strukture. Variasies in die hoërorde strukture kan toegeskryf word aan aminosuursamestelling, in besonder die
lengte van die ro-aminosuur, die aard van die C-terminale aminosuur en die geoptimiseerde
oplosmiddelkondisies wat gebruik is vir die selfmonteringsproses.
'n Derde biblioteek nuwe "hibried" bola-amfifiliese peptiedsurfaktante, waarin 'n kationiese
tripeptiedmotief uit antimikrobiale peptiede gekombineer is met 'n m-aminosuurresidu,
is geskep. Sommige van hierdie bola-amfifile het 'n kragtige antimikrobiese
aktiwiteit teenoor sowel Gram-positiewe as Gram-negatiewe bakterieë gertoon. Die
analoë strukture was aktief, of selfs meer aktief as die voorste peptiede maar het,
verbasend genoeg, nie 'n beduidende hemolitiese aktiwiteit vertoon nie. Hierdie
organopeptied bola-amfifil het dus 'n selektiewe toksisiteit teenoor bakterieë vertoon. Die
hidrofo-bisiteit, as gevolg van die ui-aminosuur, het 'n resiproke effek op hemolise en die
antimikrobiese aktiwiteit van die peptiedanaloë. Die ander uitstaande kenmerk van die
peptiede en hulle analoë is die vermoë om te selfmonteer en komplekse supramolekulêre
strukture, bestaande hoofsaaklik uit ~-plate, te vorm. Hierdie selfmontering word in
hoofsaak beheer deur hidrofobiese interaksies asook inter - en intralaagwaterstofbinding.
Elektronmikroskopie het duidelik hoërorde strukture getoon by sowel dié peptiede as
hulle analoë. Die ontwikkeling van hoërorde supramolekulêre struktuurvorms is afhanklik
van die optimalisering van die ~-plaatselfmontering. Daarteenoor is die antimikro-biese
aktiwiteit afhanklik van die balans tussen die netto positiewe lading en die opti-male
hidrofobisiteit van die peptiedhibriede.
Hierdie studie het getoon dat dit moontlik is om hibriedsurfaktante te ontwerp wat
hoërorde supramolekulêre strukture te produseer en om die antimikrobiese aktiwiteit te
verbeter terwyl die hemolitiese effek verminder word. Die studie en ontwerp van hier-die
veeldoelige, "doelmatig-gesintetiseerde" biogeïnspireerde surfakante stel 'n unieke
benadering daar, wat oor groot potensiaal beskik
Elevated salivary C-reactive protein predicted by low cardio-respiratory fitness and being overweight in African children
INTRODUCTION: C-reactive protein (CRP) is a sensitive marker of systemic inflammation and is an independent risk factor for cardiovascular disease. The aim of the study was to examine the relationship between salivary CRP, cardio-respiratory fitness and body composition in a paediatric population. METHODS: This was a cross-sectional study of 170 black South African children (age 9.41 ± 1.55 years, 100 females, 70 males) in grades 3 to 7. Unstimulated whole saliva samples were obtained for the analysis of CRP. Height, mass, skin-fold thickness, resting blood pressure, and waist and hip circumference measurements were obtained. Cardio-respiratory fitness was assessed using a 20-m multi-stage shuttle run. Children were classified as overweight/obese according to the Center for Disease Control and Prevention (CDC) body mass index (BMI) percentile ranking, and meeting percentage body fat recommendations, if percentage body fat was ≤ 25% in boys and ≤ 32% in girls. The cut-off point for low cardio-respiratory fitness was a predicted aerobic capacity value ≤ the 50th percentile for the group. Contributions of low cardio-respiratory fitness, overweight/obesity, and not meeting percentage body fat recommendations, to elevated salivary CRP (≥ 75th percentile) concentration and secretion rate were examined using binary logistic regression analysis with a backward stepwise selection technique based on likelihood ratios. RESULTS: Poor cardio-respiratory fitness was independently associated with elevated salivary CRP concentration (OR 3.9, 95% CI: 1.7–8.9, p = 0.001). Poor cardio-respiratory fitness (OR 2.7, 95% CI: 1.2–6.1, p = 0.02) and overweight/obesity (BMI ≥ 85th percentile) (OR 2.5, 95% CI: 1.1–5.9, p = 0.03) were independent predictors of elevated salivary CRP secretion rate. CONCLUSION: The results suggest a strong association between poor cardio-respiratory fitness and/or overweight/obesity and inflammatory status in children, based on elevated salivary CRP levels
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