Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie - Volume 31, Issue 1, January 2012

The correlation between cardio stress and visual skills

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Armed forces recruits were tested during a six month period of intense basic training. Data was collected at the start, after 12 weeks and 20 weeks. Means indicated significant decreases in cardio stress and increases in visual skills performance after 12 weeks and 20 weeks. Results indicate that cardio stress has a definite effect on visual performance.

The evaluation of the chronological sequence and plant dynamics on rehabilitated gold minetailings at Stilfontein, North-West Province

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The aim of the study was to evaluate the chronological sequence of vegetation establishment on the bottom parts of the western, southern and northern slopes of Dam 4 and 5 of the Chemwes gold mine tailings complex. The species composition, biomass, frequency, cover and density were measured and sampled by quadrate and transect methods. The hypothesis was that the vegetation would increase proportional to the age of rehabilitation. The study strongly supports this for some species and aspects, such as Chloris gayana, Cynodon dactylon and Andropogon eucomus. The frequency will depend on the seed mixtures and type of rehabilitation.

An investigation into agricultural cultivation techniques and the impacts thereof on soil microbial biodiversity

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The aim of this study is to determine the impacts that various cultivation techniques may have on the biodiversity of the microorganisms as well the microfauna contained within the soil. The presence of nematodes is of particular interest.

A study on the health of the Olifants River as reflected by the aquatic macro-invertebrate biodiversity and selected abiotic factors

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Aquatic macro-invetrebrates and selected abiotic factors were used to evaluate the river health. Preliminary results indicate that the ecological categories of the study sites vary from natural to critically modified and that the Target Water Quality Range is hardly ever met.

Verstedeliking en die gepaardgaande antropogeniese impakte op ekosisteme neem voortdurend toe en tree as 'n sterk selektiewe krag op wat plant-spesiediversiteit, ruimtelike verspreiding, funksionaliteit en gedrag van plantspesies beïnvloed. Relatief min studies word egter in hierdie verband in Suid-Afrika gedoen omdat die bewaringstatus van stedelike oop ruimtes soos byvoorbeeld gefragmenteerde grasvelde, laag is. Die perspesie bestaan dat grasvelde in stedelike gebiede in so 'n mate versteur is dat dit nie meer so funksioneel en spesieryk soos natuurlike grasvelde is nie. Die bewaringstatus van grasvelde in Suid-Afrika is ook oor die algemeen laag en 30% van Suid-Afrika se Grasveldbioom is getransformeer en die oorblywende 70% is tot 'n groot mate gefragmenteer. Verstedeliking en landbou-aktiwiteite is die dryfkrag agter fragmentering en transformering van die Randse Hoëveld Grasveld plantegroeitipe. Slegs 1% van dié bedreigde plantegroeitipe word tans bewaar.

Possible induction of autophagy and apoptosis by a novel 17-Beta-Estradiol analogue in esophageal carcinoma cells

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Compound C19 was tested on the esophageal carcinoma SNO cell line. Results showed induction of apoptosis and autophagy induced by C19. This contributes towards understanding its action.

Inhibition of osteoclast differentiation and bone resorption by polyunsaturated fatty acids in RAW 264.7 murine macrophages

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This study investigated the effects of polyunsaturated fatty acids on osteoclast formation and bone resorption in RAW 264.7 murine pre-osteoclasts. Data obtained suggests an inhibitory effect of these compounds on osteoclastogenesis and bone resorption in the cell line tested.

The influence of wind dispersion on the presence of cyanobacteria and algae on South African goldmine tailings

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The presence and abundance of cyanobacteria and algae in the air on mine tailings storage facilities that is rehabilitated for different periods were determined. The high density diaspores in the atmosphere of mine tailing dumps can lead to the establishment of biological crusts that can increase the stability of the mine dumps over time.

In vitro effects of arachidonic acid and prostaglandin E2 on proliferation, osteoclast formation and bone resoption in RAW 264.7 murine macrophages

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This study investigated the effects of arachidonic acid and prostaglandin E2 on osteoclast formation and bone resorption in RAW 264.7 murine pre-osteoclasts. Data obtained suggests an inhibitory effect of these compounds on osteoclastogenesis and bone resorption in the cell line tested.

Molecular crosstalk between apoptosis and autophagy induced by a 2-methoxyestradiol analogue (C19) in HeLa cells

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Using a novel synthesised sulphamoylated 2-methoxyestradiol analogue, C19, two types of cell death, namely apoptosis and autophagy, were demonstrated in vitro when cervical cancer HeLa cells were exposed to this compound.

Case study to evaluate the influence of the SolarBees and dossage on the water quality of the Rietvlei Dam Water Treatment Plant

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The aim of this project was to investigate the influence of the SolarBees and dosage on the water quality at Rietvlei Dam WTP. The difference between the raw and final water samples was less than anticipated due to the drastic improvement in raw water quality of Rietvlei Dam.

Monitoring the behavior of the Common River Frog (Amietia angolensis) with modern day technology Pit-tags

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The study was conducted in the North-West University Botanical Gardens where all 18 ponds provide habitat for the river frogs. A total of 117 river frogs were marked with pit-tags. Their movements in the garden, between and within ponds were monitored over a period of 12 months. Results showed that river frogs are active throughout the year and that males are more territorial than females.

Histological changes in the liver of two freshwater species from Roodekopjes Dam in the North West Province : preliminary results

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The aim of this poster presentation is to report on the qualitative liver histopathological findings of fish from the Roodekopjes Dam compared to the same species from a reference site, the Marico-Bosveld Dam.

The PREM Collection of fungi 1905 to 2011 : an overview

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The South Africa's National Collection of Fungi traces its origins back to 1905. Over the years the mandate has stayed the same despite the numerous changes in research focus. An overview of our activities and history will be provided.

The importance of anthropometry, physical and motor skills, sport specific testing and sports vision techniques in the evaluation of adult male rugby

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Sport has become an increasingly competitive field of expertise, thus it is imperative that an athlete is able to perform at the highest level possible at all times. Many coaches and athletes are under the false impression that performance is solely determined by physical capabilities and as a result, they fail to account for compounding factors such as: fitness levels, visual skills, body composition, nutritional status and the lifestyle habits of the athletes. If these are not optimised, they can affect a player's performance both on and off the field. Sports Vision training is a specific, safe and legal technique which can be utilised to enhance performance. Ultimately motor skills bridge the gap between fitness and technical ability, thus it is vital in training for sporting excellence - as the body must be trained to respond to what the eyes see. Making use of Sports Vision techniques, the visual system can be trained and improved in the same way that sport specific drills improve the overall performance of an athlete.

In vitro influence of 2-methoxyestradiol-bis-sulphamate on cell numbers, reactive oxygen species production and autophagy induction in a breast adenocarcinoma- and a non-tumorigenic breast epithelial cell line

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This study indicates that 2-methoxyestradiol-bis-sulphamate induces both apoptosis and autophagy and contributes to the unraveling of the action mechanism of 2-methoxyestradiol-bis-sulphamate.

The influence of an intense training programme on Cardio Stress Index

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Measurements were taken over 20 weeks from 200 armed service recruits, both males and females. There was a continuous overall decrease in the Cardio Stress Index (CSI). This study could help to establish the effects of training on the health of the heart using CSI as a measure.

Effect of selected endocrine disruptors on gene expression and male urogenital system development in male rats

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Endocrine disrupting chemicals may disrupt hormonal processes leading to impaired development. The studies aim was to investigate the relationship between various EDC exposures and development of urogenital system in male rats across two generations.

Die verspreiding en habitat van Chambardia wahlbergi en C. petersi, soos weerspieël deur data in die databasis van die Nasionale Varswaterslakversameling (NVWSV) word weergegee en bespreek. Alhoewel die verspreiding van hierdie twee spesies grootliks in die Limpopo- en Mpumalangaprovinsie oorvleuel, kom C. wahlbergi, anders as wat in die literatuur gerapporteer is, ook in die Noordwes- en Vrystaatprovinsie in die wesvloeiende Vaalrivier en in verskeie lokaliteite in die Gautengprovinsie voor. Die meerderheid monsters van beide spesies is in riviere en damme en in watertoestande wat as standhoudend, staande, helder en vars beskryf is, versamel. Multivariansie-analises het temperatuur, hoogte bo seevlak en waterliggame as faktore uitgewys wat betekenisvol tot hul geografiese verspreiding bygedra het. Min is oor die bewaringstatus van hierdie twee spesies bekend, maar die opgedateerde IUCN Rooidata-lys (Seddon et al. 2011) dui albei as nie-bedreig aan. Die meerderheid rekords van beide spesies in die databasis van die NVWSV spruit uit werk tydens die vorige eeu in die Nasionale Krugerwildtuin (NKW). Meer onlangse versamelings deur die outeurs in die NKW dui egter op 'n afname in die aantal plekke van voorkoms, asook die getalle per versamelpunt wat aan die hand doen dat daar tog rede tot kommer oor hul voortbestaan mag wees. Die feit dat besonder groot eksemplare van C. wahlbergi tot so onlangs soos 2007 meestal toevallig in die Vaalrivier aangetref is, beklemtoon die behoefte om weer omvattende opnames van varswater Mollusca, soortgelyk aan dié van die vorige eeu, van stapel te stuur om die gedokumenteerde verspreiding op te dateer en ook die vordering van eksotiese indringerspesies te moniteer.

The distribution and habitats of Chambardia wahlbergi and Chambardia petersi (Bivalvia: Iridinidae) in South Africa

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Based on the data in the database of the National Freshwater Snail Collection (NFSC), the distribution and habitat of Chambardia wahlbergi and Chambardia petersi, are presented and discussed. Although the distribution of these two species overlaps extensively in the Limpopo and Mpumalanga Provinces, contrary to reports in literature, specimens of C. wahlbergi were also collected in the North West Province and the Free State Province in the west-flowing Vaal River, as well as in Gauteng. The majority of samples of both species were collected in rivers and dams, in water conditions described as perennial, standing, clear and fresh. Multivariate analyses indicated that temperature, altitude and waterbodies played a significant role in the geographical distribution of both species. Although little is known of the conservation status of these species, it is categorised as of least concern in the revised edition of the UCN Red Data List (Seddon et al. 2011). The majority of records of both species in the database of the NFSC date from work done during the previous century in the Kruger National Park (KNP). More recent surveys by the authors in the KNP revealed a decline in the number of positive sites, as well as the number of specimens per site. This data suggest that there might be reason for concern regarding their conservation status. The fact that exceptionally large specimens of C. wahlbergi were collected, mostly by chance, on several occasions in the west-flowing Vaal River as recently as 2007 emphasises the need to conduct extensive mollusc surveys, as during the previous century, to update the documented geographical distribution and to monitor the progress of exotic invader species.

Paarprogrammering het in die industrie ontstaan waar die fokus op die ontwikkeling van programme teen die mees koste- en tyd-effektiewe wyse binne die raamwerk van kwaliteit behoort plaas te vind. Die klem is in hierdie konteks geplaas op die feit dat 'n bepaalde programkode nie deur een persoon alleen ontwikkel behoort te word nie, maar dat twee persone mekaar kan bystaan om 'n beter programkode te skryf, en mekaar ook kan aanspoor om vinniger te werk. Die probleem met hierdie benadering was egter dat beginnerprogrammeerders in die industrie nie vooraf op tersiêre vlak genoegsaam met sosiale vaardighede bemagtig is om saam te werk aan programkode nie. Die eise van die industrie, veral die sterker nadruk op samewerking in programmering, het meegebring dat paarprogrammering in die laat negentigerjare ook in die tersiêre opleiding van programmeerders veld begin wen het. Die pedagogiese beginsels waarop enige onderrig-leerstrategie gebou moes word, is in hierdie proses egter grootliks oor die hoof gesien. Hierdie artikel doen eerstens verslag oor 'n ondersoek rakende die semantiese en ontologiese onderskeid tussen koöperatiewe (cooperative) en samewerkende (collaborative) leer, en tweedens dat paarprogrammering, binne die konteks van 'n sosiaal-konstruktiwistiese benadering tot onderrig en leer as 'n samewerkende onderrig-leer strategie beskou kan word. Paarprogrammering is méér as bloot om twee leerders en/of studente saam aan 'n opdrag of programmeertaak te laat werk. Die meer gestruktureerde wyse, waarop paarprogrammering geïmplementeer moet word, stem ooreen met die beginsels van koöperatiewe leer. Daar word tot die gevolgtrekking gekom dat die korrekte pedagogiese toepassing van paarprogrammering as koöperatiewe onder-leerstrategie in tersiêre onderwys leerwins binne die onderrig-leersituasie verhoog.

Pair programming : more than just working together in pairs

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Pair programming originated in the industry where focus is placed on the development of a programme at the most cost- and time-effective manner, and within the parameters of quality. In this context, a specific programming code is not developed individually; rather, two people work together in order to ensure a higher quality programming code and to motivate each other to work at a faster pace. The problem with this approach was that novice programmers lacked the social skills to work in pairs as they had not been exposed to this sufficiently at tertiary level. The demand of the industry, especially in terms of programmers needing to be able to programme together, led to the incorporation of pair programming at tertiary level in the late nineties. The pedagogical principles on which any teaching-learning strategy should be built were, however, largely overlooked during this process. This article firstly looks into the semantic and ontological differences between co-operative and collaborative learning and secondly argues that pair programming, within the context of a social constructivist approach to teaching and learning, can be seen as a co-operative teaching-learning strategy. Pair programming is more than just allowing two students to work together on a programming task. The more structured way, in which pair programming needs to be implemented, concur with the principles of co-operative learning. The article concludes that the correct pedagogical application of pair programming as a co-operative teaching-learning strategy in tertiary education will result in improved learning capital.