Weed seed contaminants in agricultural products from China in recent years have the potential for introducing new invasive plant species. Seeds of 169 weedy species from 39 families were collected from Chinese farmlands. Fifty-eight of these that are currently absent in Canada were evaluated. Two weed risk assessment (WRA) models (modified WRA+ secondary screen tool and weed elsewhere+ modified WRA+ secondary screen tool) rejected all invasive plant species and showed similar accuracy in non-invasvie plant species prediction based on 140 existing alien plant species in Canada, yet the second WRA model took significantly less time to conduct the evaluation. Fifty-five potential invasive species with various negative impacts in Chinese farmlands were rejected to enter Canada by the “weed elsewhere+ modified WRA+ secondary screen tool” model, including eight species that cause significant damage to Chinese farmlands. However, Anemone rivularis and Silene jenisseensis, which have no negative impacts in China, were also rejected. Seed germination characteristics among 18 Chinese weedy species were found with base temperatures for germination (Tb) varying from -2.5°C to 10.9°C, thermal time requirements to reach 50% germination (θ_50) ranging from 23.7 to 209.2℃*Day, and different optimal temperatures for germination, which may facilitate these species to cause different degrees of negative impacts in Canadian prairie provinces. An alien species would have a higher competitive advantage in resource uptake and space occupation than its congeneric with advantageous seed germination characteristics; otherwise it will be less competitive than its congeneric. In addition, plant functional traits that promote invasiveness would make an alien species more invasive. In conclusion, the “weed elsewhere+ modified WRA+ secondary screen tool” model is a fast and highly accurate way to screen out potential invasive species from Chinese environments, and is applicable to other environments with modification. Seed germination characteristics can be used to predict seasonal dynamics of weed seedling populations. The comparison of seed germination characteristics and other plant functional traits between alien plant and its congeneric weed from native areas provides a new way to evaluate the invasive potential of alien plant species.

Dissertation submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic, Durban University of Technology, 2009. / Manual therapists are susceptible to occupational low back pain. The aim of this study was to determine the prevalence and risk factors for occupational low back pain in manual therapists and to determine and compare the prevalence and risk factors for occupational low back pain among various types of manual therapists in South Africa. This study was conducted as a cross-sectional survey and a self-administered questionnaire, developed from the literature and validated prior to the study, was mailed to 1500 randomly selected manual therapists, including: physiotherapists, occupational therapists, biokineticists, chiropractors, reflexologists, aromatherapists and massage therapists. A total of 233 completed questionnaires were returned, giving a response rate of 15.53%. Results revealed that the point prevalence of low back pain in manual therapists was very high at 41%, the one-year prevalence was 59% and the career prevalence was 74%. The point prevalence of low back pain was highest in aromatherapists and biokineticists, while both the one-year and career prevalence of low back pain was highest in occupational therapists and massage therapists. The risk factors for low back pain in manual therapists were: BMI; previous abdominal surgery; previous trauma to the low back, hips, knees or ankles; a physically stressful job; not having an assistant and work in a hospital or other setting. In keeping with the literature, various workrelated factors were implicated in the development and / or exacerbation of low back pain in certain manual therapists more than others and low back pain history in the different manual therapists was also in accordance with the literature. To conclude, low back pain is prevalent among South African manual therapists and the development and implementation of preventative programs to reduce rates of occupational low back pain in manual therapists is mandatory.

Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2011. / Please refer to full text for abstracts

Abstract Background: Consumer interest and demand for healthy and ecologically produced local food has led to a high market demand that local production cannot meet. Product attributes of perishability and short life cycles ensure that even local supply chains are challenging to manage. This increases potential for risks occurrence in an Organic Food Supply Chain (OFSC) especially with unreliable supply of products. Small and established food retailers import organic food products from across the world. Custom delays, high transport charges, commodity costs and regulatory requirements are associated with food imports. This renders OFSCs complex and vulnerable to disruptions or breakdowns that require appropriate strategies to identify and mitigate risks. Purpose: To gain an overall insight of risks mitigation in OFSCs. The purpose of this thesis is to assess risks affecting suppliers and retailers of organic food and propose risk mitigation strategies to prevent or minimise supply chain breakdowns. Method: This qualitative study utilizes a case study strategy involving seven case firms and seven research respondents. Data is collected through semi-structured interviews and documentary secondary data. The analysis of the empirical findings is conducted by cross analysing empirical findings of respective case firms and then emerging patterns are formulated into a general framework. Conclusions: Low conversion rates of farms for organic production, high costs of investments and regulatory requirements have contributed to prevailing production risks that partly cause low organic output. Other risks identified that could disrupt the food chain under study include sourcing, warehousing, demand, price, financial and institutional risks. Mitigation strategies proposed include production procedures, CAP, supply chain flexibility, supply chain visibility, certification, diversification of retail channels, brand image building, horizontal & vertical cooperation and buyer-supplier relations.

In the staffing agency business, the responsibility of the working environment are divided between the client companies and the staffing agencies. Therefore the temporary workers should be double protected, but the consequences are that the responsibility of the working environment falls between the cracks in many businesses.The purpose of the essay is to examine how the workers in industrial businesses from the staffing agency are protected by the shared responsibility that exists between the client companies and the staffing agencies, regarding work environment. To be able to answer this questions, the legal method is used.The conclusion of this essay is that the temporary workers are protected by the Work Environment Act, stating that the staffing agency and the client company have a responsibility for the employee´s work environment. Since the staffing agency is the employer, they have the largest work environment responsibility. This means, however, that staffing agencies are in a special situation because they are not in the place where the employee works. Since the client company is equated with an employer according to 1 § SAM, the systematic work environment is shared equally between the client companies and staffing agencies. On the grounds that there is a lack of clarity concerning who is responsible for what from the both parties, it leads to that the working environment responsibility are neglected. It also depends on the fierce competition that exists between various staffing companies today, which means that staffing companies do not always take part of the client companies' risk assessments or requirements on the grounds that they are afraid of losing the customer. This results that the temporary employees do not get the protection that the Work Environment Act is intended to give them.

Thesis (MA) -- University of Stellenbosch, 2000. / ENGLISH ABSTRACT: Judgement of risk for negative events in certain situations was investigated in a group of emergency medical service (EMS) personnel with a diagnosis of posttraumatic stress disorder (PTSD; n = 27) and a group without PTSD (n = 74). Participants completed the PTSD Symptom Scale: Self-Report version (Faa, Riggs, Dancu, & Rothbaum, 1993), an EMS work experiences questionnaire, the Beck Depression Inventory (Beck, Rush, Shaw, & Emery, 1979), and an event probability questionnaire designed to assess judgement of risk. Participants with PTSD overestimated amount of risk involved in comparison to participants without PTSD, thereby demonstrating a judgement bias for risk related events. The present study found that the judgement bias in PTSD participants extended to include not just external harm related events but also general negative events (without potential threatening/harmful consequences), negative social events, and negative workrelated events. Of the posttraumatic symptomatology assessed, avoidance symptomatology was found to be the best predictor of judgement bias. The results of the present study are discussed in terms of the cognitive clinical psychology theories of PTSD, which predict the manifestation of judgement bias in PTSD, and cognitive experimental psychology explanations of the effect of negative emotional states on judgement processes. / AFRIKAANSE OPSOMMING: Oordeeloor risiko vir negatiewe gebeurtenisse in sekere situasies is ondersoek by "n groep mediese nooddienspersoneel met "n diagnose van posttraumatiese stresversteuring (PTSV; n = 27) en "n groep sonder PTSV (n = 74). Deelnemers het die PTSD Symptom Scale: Self-Report version (Foa, Riggs, Dancu, & Rothbaum, 1993), "n mediese nooddiens werkservaringe-vraelys, die Beck Depression Inventory (Beck, Rush, Shaw, & Emery, 1979), en "n gebeurtenis-waarskynlikheidsvraelys wat opgestel is om oordeeloor risiko te meet, voltooi. Deelnemers met PTSV het die mate van risiko betrokke oorskat in vergelyking met deelnemers sonder PTSVen sodoende "n beoordelingsydigheid vir risiko-verbandhoudende situasies gedemonstreer. In die huidige studie is gevind dat beoordelingsydigheid by PTSV deelnemers nie beperk was tot eksterne skade-verbandhoudende gebeurtenisse nie, maar dat dit ook veralgemeen het na algemene negatiewe gebeurtenisse (sonder potensieel skadelike gevolge), negatiewe sosiale gebeurtenisse, en negatiewe werksverwante gebeurtenisse. Daar is gevind dat, wat PTSV-simptomatologie betref, vermyding die beste voorspeller van beoordelingsydigheid was. Die resultate van die huidige studie word bespreek in terme van kognitiewe klinies-sielkundige teorieë van PTSV, wat die aanwesigheid van beoordelingsydigheid voorspel, en kognitiewe eksperimentele-sielkunde verklarings van die effek van negatiewe emosionele toestande op beoordelingsprosesse.

On t.p.: Master of Arts (Clinical Psychology) / Thesis (MA)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Progress has been made in the approach to combating the spread of HIV/AIDS with regards to the Department of Health's presentation of the HIV/AIDS/STD Strategic Plan for South Africa. However, deep concem exists with regards to specific marginalized groups such as disabled persons within the South African sector threatened by the spread of HIV/AIDS. The aim of this paper was to review published academic papers on the specific ways in which disabled people are at risk for contracting HIV/AIDS, and the existence of primary prevention programmes designed and specifically aimed at the disability sector. The roles of non-governmental and other organisations were also looked at. The first section of the review focused on high-risk behaviour among disabled persons for contracting HIV/AIDS. Existing literature covered mainly areas of intellectual disability and psychiatric disability. Disabled persons struggle with the same issues of good education, workers' rights, gender equality, health care and social support and well-being as the general population. These issues are however exacerbated by struggles unique to those living with a disability. Inadequate public and social support increase disabled people's vulnerability to issues such as poverty, lack of resources, and inadequate education, heightening their risk of contracting HIV/AIDS. The second section of the review discusses the area of primary prevention, explaining why prevention programmes should be tailormade for specific needs such as those of disabled persons. Examples of prevention programmes from the literature are looked at, as well as a prevention initiative launched in South Africa. / AFRIKAANSE OPSOMMING: Vooruitgang is gemaak op die gebied van die voorkoming van die verspreiding van MIVNIGS met die bekendstelling van die Departement van Gesondheid se MIVNIGS/STD Strategiese Plan vir Suid-Afrika. Daar is wel steeds kommer oor spesifieke gemarginaliseerde groepe, soos gestremde persone, binne die Suid- Afrikaanse sektor wat bedreig word deur die verspreiding van MIVNIGS. Die doel van die studie was om 'n oorsig te kry van akademiese materiaal wat gepubliseer is oor die spesifieke wyses waarop mense met 'n gestremdheid in gevaar verkeer om MIVNIGS op te doen, asook primêre voorkomingsprogramme wat spesifiek ontwerp en gemik is op die gestremde sektor. Daar is ook gekyk na die rol van nie-regerings- en ander organisasies. Die eerste deel van die studie fokus op hoë risiko gedrag van gestremde persone wat hulle in gevaar mag stel vir die opdoen van MIVNIGS. Bestaande literatuur handel meestaloor die areas van intellektuele gestremdheid en psigiatriese siektes. Gestremde persone moet dieselfde uitdagings oorkom as diegene in die algemene populasie, soos byvoorbeeld die gebrek aan goeie onderwys, arbeidsregte, diskriminasie op grond van geslag, gesondheidssorg, asook sosiale steun en algemene welsyn. Gestremde persone se kwessies word egter vererger deur sekere uitdagings wat uniek is aan 'n lewe met 'n gestremdheid. Gestremde persone ontvang meestalonvoldoende publieke en sosiale steun wat dikwels armoede, gebrek aan hulpbronne en onvoldoende opvoeding tot gevolg het. Laasgenoemde verhoog gestremde persone se kanse om MIVNIGS op te doen. Die tweede deel van die studie bespreek primêre voorkomingsprogramme en waarom dit noodsaaklik is om voorkomingsprogramme te ontwerp wat uitsluitlik gemik is op spesifieke populasies. Daar word dan ook gekyk na voorbeelde van primêre voorkomingsprogramme in die literatuur, asook 'n voorkomingsinisiatief wat in Suid-Afrika geloods is.

Thesis (MBA)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: With globalisation and the accompanying increase in international trade there is a great drive towards performing risk assessments on the quality of products. Such assessments are of particular importance within the food and drug industry, so much that this approach is also being adapted by the FDA in their analysis of the quality of products and probable risks to it. The pharmaceutical industry is heavily regulated to reduce or eliminate the production and distribution of poor quality products. Pharmaceuticals have to be of high quality as people's lives depend on it. Many pharmaceutical companies import raw materials from international manufacturers or international agents. In most cases the raw material or the products have to go through a long and complicated supply chain. The more parties involved in the supply chain, the greater the risk to product quality. Supply chain partnerships have therefore become critical to manage these risks to product quality throughout the supply chain. In order to manage risks to product quality, it has become vital to perform product quality risk assessments, especially through the supply chain. In this study the Failure Mode Effect Analysis (FMEA) is used to perform a risk assessment of risks to product quality throughout the supply chain. To obtain the criticality of the risks the Failure Mode Effect and Criticality Analysis (FMCEA) is applied. Quality improvement systems which contribute towards managing the risks to product quality are also discussed in this report. By managing quality risks to pharmaceutical products along with using quality as a strategy, the pharmaceutical company contributes towards improved health for patients as well as customer satisfaction, business success and excellence. / AFRIKAANSE OPSOMMING: Die toepassing van die analise van die risiko op produkte is vinnig besig om te vermeerder. Die FDA gaan dit toepas in hulle analise van die kwaliteit van produkte en die risiko wat daarmee gepaard gaan, in die voedsel en medisyne bedryf. Die farmaseutiese industrie word baie streng gereguleer om te verhoed dat die produksie en distribusie van swak kwaliteit produkte ervaar word. Farmaseutiese produkte moet van hoë gehalte wees, omdat die gesondheid van pasiënte daarvan afhang. Baie farmaseutiese maatskappye bestel rou materiale van oorsese makelaars en in baie gevalle moet die rou materiale deur 'n lang en gekompliseerde voorsieningsketting gaan. Hoe meer agente betrokke is, hoe hoër word die risiko met respek tot die kwaliteit van die produk. Die voorsieningsketting speel 'n kritiese rol om te verseker dat risikos beheer kan word, omdat elke party verantwoordelik is vir die lewering van kwaliteitsprodukkte. Om te verseker dat risikos beheer word, het dit belangrik geword om risiko analise te doen op die kwaliteit van produkte, veral wanneer in die voorsieningsketting. In hierdie studie word die "Failure Mode Effect Analysis (FMEAJ' gebruik om 'n risiko analise te doen met betrekking tot risikos op 'n produk se kwaliteit wanneer in die voorsieningsketting. Die "Failure Mode Effect, and Criticality Analysis (FMECAJ', word ook toegepas om te bereken hoe krities die risiko is. Verbeteringstelsels wat bydra tot die beheer en kontrole van risikos vir produk kwaliteit word ook in hierdie studie bespreek. Deur die risikos te beheer op die kwaliteit van produkte, dra die farmaseutiese maatskappy by tot beter gesondheid vir pasiente, en verseker klient satisfaksie en suksesvolle besigheid.

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Exposure to food contaminates such as mycotoxins have been associated with a variety of animal and human diseases worldwide. In South Africa, maize is the most To further refine risk assessment in the socio-demographic heterogeneous population of South Africa, the development and evaluation of a sensitive and interactive model the Mycotoxin Risk Assessment Model (MYCORAM) proofed to be more sensitive compared to the classical probable daily intake (PDI). The development of the MYCORAM was based on mycotoxin distribution during dry milling of maize in milling fractions intended for human consumption which was superimposed on the maize intake profiles of the South African population. Although dry milling, including a degerming step, is an effective way to reduce mycotoxins, risk and exposure assessment are influenced by maize dietary intakes, gender and ethnicity. This became evident when considering FB dietary exposure in rural maize subsistence farming communities in the Eastern Cape Province, South Africa confirmed the vulnerability of this subpopulation to risk of fumonisin exposure. Specific maximum tolerated maximum levels (MTL) to safeguard these communities fall outside the international regulatory processes and need to be urgently addressed. With the complex nature of cancer development in mind, integration of basic science and nutritional epidemiology will be important to contribute to our understanding of the adverse effects of FB and to define relevant risk assessment parameters. important commercial grain crop not just economically but also as a local food commodity both commercially and in subsistence rural farming communities. In order to control and manage mycotoxin contamination in food, evidence-based risk assessment is needed that includes mechanistic and human exposure studies. From this perspective the current study was conducted and aimed in further unravelling fumonisin B1 (FB1) mycotoxin induced hepatocarcinogenesis via the disruption of the lipid metabolism. The study also critically evaluates aspects of human risk assessment due to its relevance and importance to food safety known to impact on food security. This entails mycotoxin distribution during maize dry milling and the assessment of mycotoxin exposure in the South African population and vulnerable rural communities at risk. Fumonisin B1 affects the integrity of biological membranes by altering key lipid and fatty acid parameter in plasma, microsomal, mitochondrial and nuclear subcellular membrane fractions in rat liver. Changes in the major lipid constituents entailing an increase in cholesterol (CHOL) and phosphatidylethanolamine (PE) whilst sphingomyelin (SM) and phosphatidylcholine (PC) tended to decrease. Isolated plasma membrane lipid rafts, from rat primary hepatocytes exposed to FB1 augments the intricate effects exerted on the lipid metabolism regarding CHOL, SM and PE. The disruption of lipid and fatty acid constituents, such as arachidonic acid and ceramide, are likely to be key determinants affecting growth regulatory signaling pathways relevant to the critical balance between cell proliferation and apoptosis during cancer promotion. These changes provide further evidence that FB1 induce cancer promotion by differential inhibition and/or stimulation process whereby a few resistant “initiated” hepatocytes proliferate in an environment where the growth of normal cells is inhibited. A specific lipogenic phenotype is effected by FB1 which is closely associated with cancer development and considered to occur via an epigenetic-type of mechanism. These effects are not adequately addressed in defining risk assessment parameters. / AFRIKAANSE OPSOMMING: Die blootstelling aan voedsel-kontaminante soos mikotoksienes word wêreldwyd met ‘n verskeidenheid van dierlike en menslike siektes geassosiseer. In Suid-Afrika word mielies as ‘n belangrike graanoes beskou, nie net vir die ekonomie nie maar ook as ‘n plaaslike voedselproduk beide kommersieel en vir bestaansboere in landelike gemeenskappe. Ten einde mikotoksien-kontaminasie van voedsel te kan beheer en bestuur, vereis bewys-gebaseerde risiko-evaluering wat insluit meganistiese en menslike blootstelling studies. Vanuit hierdie perspektief is die huidige studie uitgevoer en gemik op die verdere ontleding van die fumonisin B1 (FB1) mikotoksien geïnduseerde lewer-karsinogenese deur die ontwrigting van die lipiedmetabolisme. Die studie ondersoek terselfdetyd aspekte van menslike risiko-evaluering ingevolge die relevansie en belangrikheid hiervan in voedselveiligheid wat ook ‘n impak op voedselsekerheid sal maak. Dit sluit in die verspreiding van mikotoksiene gedurende die droëmaalproses van mielies en mikotoksien blootstelling in Suid-Afrika asook onder kwesbare landelike gemeenskappe. Fumonisin B1 beïnvloed die integriteit van biologiese membrane deur die modulasie van die belangrike lipied en vetsuur samestelling van plasma, mikrosomale, mitochondriale en kern subsellulêre membraan-fraksies in rot lewer. Veranderinge in die belangrike lipiedbestanddele, insluitende ‘n verhoging in cholesterol (CHOL) en phosphatidylethanolamine (PE), terwyl sphingomyelin (SM) en phosphatidylcholine (PC) geneig was om te verlaag. Geïsoleerde plasma membraan lipied vlotte (lipid rafts), vanaf primêre rot hepatosiete blootgestel aan FB1, versterk die ingewikkelde gevolge wat uitgeoefen word op die lipiedmetabolisme insluitende die voorgestelde veranderings in CHOL, SM en PE vlakke. Die versteuring van lipiede en vetsure soos aragidoonsuur (arachidonic acid) en ceramied kan beskou word as belangrike determinante wat inmeng in groei-regulerende seinbane verwant aan die kritiese balans tussen selgroei en seldood. Die versteurings verskaf verdere bewyse dat FB1 kanker bevorder deur ‘n seleksie proses wat onderskeidelike die onderdrukking en\of die stimulasie van ‘n paar weerstandige of geneties veranderde hepatosiete laat vermeerder in ‘n omgewing waar die groei van normale selle geïnhibeer word. Die spesifieke lipogeniese fenotipe wat FB1 versoorsaak hou ten nouste verband met kankerontwikkeling en die voorkoms van epigenetiese-soort meganismes word voorgestel. Hierdie oorsake word tans nie voldoende aangespreek tydens die bepaling van risiko-evaluerings limiete nie. Om risiko-bepaling verder te verbeter in die sosio-demografies heterogene populasie van Suid-Afrika, was die ontwikkeling en evalueering van ‘n sensitiewe en interaktiewe model, die “Mycotoxin Risk Assessment Model” (MYCORAM) meer doeltreffend vergeleke met die gewone waarskynlike daaglikse inname. Die ontwikkeling van die MYCORAM was gebaseer op die mikotoksien verspreiding tydens die droëmaalproses van mielies in fraksies wat vir menslike verbruik bedoel was tesame met mielie dieetinnames van die Suid-Afrikaanse populasie. Alhoewel, die droëmaalproses van mielies, insluitende die verwydering van die kiem doeltreffende maniere is om mikotoksienes te verminder, word risiko- en blootstellings evaluering beinvloed deur mielie dieetinnames, geslag en etnieseverbandskap. Hierdie was veral opmerklik gedurende blootstelling aan FB in die dieet van landelike mielie bestaansboer gemeenskappe in die Oos-Kaap van Suid- Afrika en bevestig hoe kwesbaar hierdie populasie is. Spesifieke maksimum toelaatbare vlakke om hierdie gemeenskappe te beskerm val buite die huidige internasionale regulatoriese prosesse en benodig dringende aandag. Met die ingewikkelde aard van kankerontwikkeling in gedagte, sal die integrasie van basiese wetenskappe en voedingsepidemiologie, ‘n belangrik bydrae lewer tot die kennis van die negatiewe eienskappe van FB om toepaslike risiko-evaluerings limiete te kan bepaal.

The purpose of this thesis is to explore differences in lifetime excess cancer risk (LECR) for Canadians from intake of contaminants in food and beverages based on geographic location, gender and income levels. A probabilistic risk assessment approach (Monte Carlo simulation) was used to estimate the range and frequency of possible daily contaminant intakes for Canadians, and associate these intake levels with lifetime excess cancer risk. Monte Carlo risk simulation was applied to estimate probable contaminant intake and associated lifetime excess cancer risk from arsenic, benzene, lead, polychlorinated biphenyls (PCBs) and tetrachloroethylene (PERC) in 60 whole foods from the dietary patterns of 34,944 Canadians from 10 provinces, as derived from Health Canada’s Canadian Community Health Survey, Cycle 2.2, Nutrition (2004)1. These results were compared to the current Health Canada guideline that suggests that 10 extra cancers per one million people is a negligible risk. Of the 5 contaminants tested in my model arsenic showed the greatest difference between urban and rural estimated lifetime excess cancer risk, although extra cancers in both rural and urban Canada were predicted from exposure to PCB and benzene. Lifetime excess cancer risk is estimated to be higher for men in Canada for all five contaminants, with an emphasis on males in British Columbia compared to females from the dietary intake of arsenic. When based on income level, my model predicts extra cancers higher for low and middle incomes from dietary exposures to arsenic, benzene, lead and PERC, however, high income populations are more likely to have extra cancers from dietary intake of PCBs. / Graduate