Right bundle-branch block associated with transient left posterior hemiblock in a case of acute myocardial infarction

The intraventricular conduction defect of left posterior hemiblock is very uncommon. Its occurrence as a transient phenomenon during the course of acute myocardial infarction, as described in this report, is exceptionally rare. The presentation revealed a planar reorientation of QRS forces, and demonstrated the masking effect of left posterior hemiblock on the parameters of anterolateral myocardial ischaemia.S. Afr. Med. J., 48, 1237 (1974)

Sensory quality control : Assessment of food company employees' knowledge, attitudes, and practices

This study was carried out to validate a questionnaire for assessing sensory quality control (SQC) knowledge, attitudes, and practices (KAP). The questionnaire, containing 24 knowledge, 13 attitudes, and nine practices items, was submitted to company representatives in South Africa and Nigeria. Confirmatory factor analysis and group comparisons among respondents and companies were carried out to validate the questionnaire. The final SQC-KAP questionnaire consists of 24 knowledge (one scale), 11 attitudes (A bifactor scale, with a general scale and two subscales representing individual attitudes to SQC and those towards company SQC) and nine practices (one scale) items. The knowledge items had acceptable indices for difficulty and discrimination, and the attitudes and practices items had acceptable item-total correlations. The final questionnaire can be used for the rapid assessment of SQC related knowledge and attitudes of food company employees and assessment of company practices. Practical Applications This study is the first to validate a questionnaire for assessing SQC related knowledge, attitudes, and practices in the food industry. The SQC-KAP questionnaire can be used to rapidly assess SQC knowledge and attitudes of food company employees for sensory services, and to identify SQC training needs. Stakeholders can also use it to assess the sensory quality practices of food companies to gauge their compliance to good practice and identify potential areas of improvement of their SQC programs.Peer reviewe

Epidemiology of urethral stricture at Tygerberg Hospital

Over a 12-month period, 120 consecutive male patients with confirmed urethral stricture were prospectively studied with regard to the epidemiology of the disease. Specific urethritis is the main aetiological factor (45%) and internal and external trauma account for an alarming 38,3% of cases. The prevalence is highest among 40 - 50-year-old coloured men who have had little schooling, multiple sexual partners and who have a low annual income. The incidence can be reduced by upliftment of moral and educational standards of the local population, and by emphasising the potential dangers of catheterisation and instrumentation to m.edical personnel

The sensory profiles of flatbreads made from sorghum, cassava, and cowpea flour used as wheat flour alternatives

Sorghum, cowpea, and cassava are underutilised gluten-free sources of flour that have the potential to be used in bread products in sub-Saharan Africa. Excessive wheat imports affect the economies of countries in sub-Saharan Africa, driving the search for wheat flour alternatives. To extend the use of sorghum, cowpea, and cassava flours toward bread production, it is vital that the sensory properties of these flours are better understood. A trained sensory panel evaluated and described the sensory properties of flatbread models prepared from red non-tannin sorghum, fractions (whole and dehulled) of two cowpea varieties, cassava starch, and designated flour composites. The composites were prepared using cassava starch and sorghum flour at 0%, 35%, and 70%, respectively, with 30% cowpea flour. The addition of sorghum intensified sorghum aroma in flatbread, while cowpea flours contributed a beany flavour. Flatbreads from cassava-cowpea composites had a chewier and rubberier mouthfeel, an intense fermented aroma and flavour, and a sour aftertaste compared to single flours, but were most similar to the wheat flatbread, with a residual beany flavour. Information from this study can guide food product developers toward developing new bread products from sorghum, cassava, and cowpea composite flours, thereby moving Africa towards a more sustainable food system. Further research on the effects of the sensory characteristics on consumer liking of the flatbreads is needed

A semi-quantitative survey of macroinvertebrates at selected sites to evaluate the ecosystem health of the Olifants River

This study was conducted to evaluate the ecosystem health of the Olifants River by means of semi-quantitative surveys of the macroinvertebrates at 7 selected sites in the catchment. These surveys were performed during the high- and low-flow seasons for 2 consecutive years. Macroinvertebrates were collected by using a net consisting of a 30 cm square steel frame with a sturdy handle, to which a Perlon gauze net with a mesh of 1 mm was attached. Semi-quantitative surveys were done by sampling the vegetation, as well as the substratum, with the net at each site for approximately 15 min. The pH, water temperature and conductivity were measured in situ at each site during the different surveys. Samples were fixed and preserved in 90% ethanol and thereafter sorted, identified up to family level and counted. The specimens were categorised as tolerant, moderately sensitive or highly sensitive, according to the guidelines set by the South African Scoring System Version 5 (SASS5). Although a total of 95 taxa were recovered during this study, only 7 of these taxa were categorised as highly sensitive, it can be concluded that the water of the Olifants River is in a poor state of health as revealed by the macroinvertebrate assemblages.Keywords: Olifants River, macroinvertebrates, river healt

A comparison of mollusc diversity between the relatively pristine Marico River and the impacted Crocodile River, two major tributaries of the Limpopo River, South Africa

A study of the freshwater mollusc diversity was conducted at selected sites in the relatively pristine  Marico River and the impacted Crocodile River, the major tributaries of the Limpopo River. Four  surveys were conducted, two in an early (May 2013 and 2014) and two in a late (November 2013 and 2014) low-flow period. Semi-quantitative surveys were done by sampling the vegetation, as well as the substratum, with a standard SASS net for approximately 15 min each. Environmental parameters including water temperature, electrical conductivity (EC) and pH were measured at each site. Molluscs were identified up to species level, sorted, counted, and the presence of juvenile specimens recorded. Historical data for the 1/16th degree square grids (loci), in which each of the sampling sites of the current study was located, were extracted from the National Freshwater Snail Collection at the Unit for Environmental Sciences and Management, Potchefstroom Campus of the North-West University. During this study, 20 and 9 species were recovered from the Marico and Crocodile Rivers, respectively, as compared to 13 and 12 species on record for these loci, respectively. Juvenile specimens were present during the four surveys at most of the sites. Canonical correspondence analyses were applied which revealed that biotopes, water temperature and EC played the most significant role in the distribution and abundance of species. The relatively high mollusc diversity and the fact that juveniles were present throughout the study, demonstrated that current habitat and environmental conditions were suitable to promote recruitment and the sustainability of diverse mollusc populations in the Marico River and its tributaries. However, in contrast to this, the exploitation of and habitat transformation in the Crocodile River has resulted in the decrease of biotopes which eventually could have led to the  decrease in diversity and the establishment of P. acuta, an exotic invader species.Keywords: freshwater molluscs, biodiversity, Marico River, Crocodile River, environmental variable

Gain of 20q11.21 in human pluripotent stem cells impairs TGF-β-dependent neuroectodermal commitment

Gain of 20q11.21 is one of the most common recurrent genomic aberrations in human pluripotent stem cells. Although it is known that overexpression of the antiapoptotic gene Bcl-xL confers a survival advantage to the abnormal cells, their differentiation capacity has not been fully investigated. RNA sequencing of mutant and control hESC lines, and a line transgenically overexpressing Bcl-xL, shows that overexpression of Bcl-xL is sufficient to cause most transcriptional changes induced by the gain of 20q11.21. Moreover, the differentially expressed genes in mutant and Bcl-xL overexpressing lines are enriched for genes involved in TGF-beta- and SMAD-mediated signaling, and neuron differentiation. Finally, we show that this altered signaling has a dramatic negative effect on neuroectodermal differentiation, while the cells maintain their ability to differentiate to mesendoderm derivatives. These findings stress the importance of thorough genetic testing of the lines before their use in research or the clinic

Non-persistente virusoverdracht door bladluizen in bloembollen

Dit driejarig onderzoeksproject naar non-persistente virusoverdracht door bladluizen in bloembollen heeft direct toepasbare kennis en gewasbeschermingsadviezen opgeleverd, maar ook heldere adviezen voor zowel de chemische als biologische bestrijding van virusoverdracht door bladluizen. Deze adviezen vormen de basis voor verder onderzoek om uiteindelijk de non-persistente virusverspreiding door bladluizen nog effectiever te kunnen bestrijden

Texture and mineralogy influence on durability: The Macigno sandstone

The behaviour of ornamental stones in response to environmental changes or interactions is crucial when dealing with the conservation of cultural heritage.Weathering factors affect each rock differently, depending on structure, mineralogy, and extraction and implementation techniques. This work focuses on the Macigno sandstone, a dimension stone often employed in Tuscany over the centuries. A thorough mineralogical (optical microscopy, scanning electron microscopy and X-ray powder diffraction) and petrophysical characterization (i.e. mercury intrusion porosimetry, X-ray computed tomography, hygroscopic adsorption behaviour, ultrasounds, image analysis and capillary uptake) was made of the sandstone type extracted in the area of Greve in Chianti. The lithotype shows mineralogical (i.e. presence of mixed-layer phyllosilicates) and microporosimetric features, leading to a high susceptibility to relative humidity variation. Moreover, the influence of swelling minerals is related to weathering due to saline solution. The joint application of petrographic and petrophysical techniques allows an understanding of the characteristic weathering pattern of exfoliation (i.e. detachment of multiple thin stone layers, centimetre scale, that are sub-parallel to the stone surface)