Food is an integral part of everyday life, and food choices directly affect one’s health. Both academics and practitioners have attempted to help consumers make good decisions about their food choices and recommended better or healthier alternatives. However, in thinking about food it is important to put it in context, as each food item is often combined with other food items to create the gestalt of a recipe or meal. Understanding the complex interaction between food items that are used or consumed together is crucial to provide effective recommendations. In this research, I leverage tools from machine learning and textual analysis like the embedding approach for representation learning to understand food in its context and to build recommender systems that account for the complementarity or fit of co-consumed food items. I show that this consideration of fit among food items can lead to better and healthier food recommendations.

This research is a qualitative study that aimed to anthropologically explore the effects of consistent long-term yogic practice on the acceptance and practice of complementary and alternative medicine (CAM) among yoga practitioners at a South Florida yoga center. I wished to determine, through in-depth interviews, whether or not yogic practice affects acceptance of CAM. The main objective was to interview individuals from a single yoga center that have practiced yoga at least once per week for at least one year concerning their beliefs about CAM, yoga, and health. This project will begin to fill the gap in social science, in general, and specifically, the anthropological literature. Scholars of various backgrounds have discussed elements of yogic practice and philosophy that were integral to my understanding of the data. The health benefits of yoga as CAM, the associations between yoga and beliefs about health, and the association between yoga and Indian philosophy and medicine have each been explored. However, anthropological scholarship discussing the effects of consistent, long-term yogic practice on the acceptance of other CAM’s or Western biomedicine has not been examined.

Circulating cell-free mitochondrial DNA (cf-mtDNA) is an emerging biomarker of psychobiological stress and disease which predicts mortality and is associated with various disease states. First, I present a systematic review of the literature that shows cf-mtDNA levels respond to common real-world stressors. The review discusses current knowledge on the mechanisms of cf-mtDNA release, its molecular forms of transport, potential physiological functions, cellular and neuroendocrine triggers, and factors that may contribute to cf-mtDNA removal from the circulation. Second, to evaluate the contribution of cf-mtDNA to health and disease states, standardized high-throughput procedures are needed to quantify cf-mtDNA in relevant biofluids. I describe the development of MitoQuicLy: Mitochondrial DNA Quantification in cell-free samples by Lysis. I demonstrate high agreement between MitoQuicLy and a commonly used column-based method, although MitoQuicLy is faster, cheaper, and requires a smaller input sample volume. I find that cf-mtDNA levels between concurrently collected plasma, serum, and saliva from the same individual differ on average by up to two orders of magnitude and are poorly correlated with one another, pointing to different cf-mtDNA biology or regulation between commonly used biofluids in clinical and research settings. Finally, I deploy MitoQuicLy in a highly phenotyped cohort of participants with mitochondrial disease and healthy controls to quantify the impact of a brief psychological stressor on cf-mtDNA levels in three biofluids and evaluate how cf-mtDNA release varies between individuals, biofluids, and mitochondrial disease status. These studies set the stage for a research agenda identifying novel links between psychological stress and physiological response, which may improve our understanding of how stressful experiences increase disease risk. In the future, cf-mtDNA release or its downstream effects may be targeted to modulate the impact of psychological stress on human health.

Mental health care, other than being a critical medical service, is a centrally important cultural institution, shaping individuals’ understanding of their lives and problems. This dissertation consists of a multi-method investigation examining the U.S. mental health care field from these two intersecting perspectives. To achieve this, it examines (1) how structural conditions determine different social groups’ access to different mental health care services; (2) what effects these disparities in access have on individuals’ experiences when seeking care and on the outcomes they face; (3) how the stratification of the mental health care field exposes different Americans to different sets of cultural scripts and understandings, generating correspondence between sociodemographics and intimately-held meanings and normative action scripts for mental well-being. Its four chapters thus tackle mental health care’s social significance from multiple angles, using geospatial, computational text analysis, and audit methods, seeking to provide actionable, public health policy-relevant empirical research concerning inequalities in access to care, as well as to address key theoretical problems regarding the segregation of meaning-making with which sociology has long contended.

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Thesis (M. Tech. ) - Central University of Technology, Free State, 2006 / Antibiotics have been used on animals since the Second World War for therapeutic purposes. The risks associated with the use of antibiotics in food animals are enormous, due to the possibility of resistance of organisms caused by the usage of low levels of antibiotics. The goals of this study were to determine the prevalence of antibiotic residues in C grade milk cows, and to determine the practices and knowledge of producers regarding the use of antibiotics as well as the knowledge and habits of consumers. In the study the presence of antibiotic residues was tested by means of microbiological inhibition testing. Fifteen percent of all tested samples tested positive for the presence of antibiotic residues. Eleven samples that tested positive on the microbiological inhibition test were sent to the Onderstepoort Veterinary Institute for confirmation. The knowledge of the consumer as well as that of the producer was tested by means of a questionnaire and then processed statistically. Producers were, in general, fairly ignorant regarding the withdrawal period of antibiotic residues. Age and the combination of age and reproduction were the common reasons for the selling of milk cows. Both the sampling and the questionnaires proved that the presence of antibiotic residues is higher than that stated in literature. The selling of the animals was mostly by auction or directly to the abattoirs. Consumer practices regarding the antibiotic residues were mostly in order, although consumers did not have knowledge regarding antibiotic residues. High temperatures, for example in the frying or grilling of meat, will reduce the presence of antibiotic residues because these effects have an influence on the presence of antibiotic residues (Rose et al., 1995). Almost 75% of consumers describe antibiotics in a positive manner. Milk and meat are regarded as posing the greatest risk for the origin of antibiotic residues. A lack of general knowledge regarding antibiotic residues was noteworthy, especially from the consumers of Thaba ’Nchu and Heidedal. The wrong usage of antibiotics by medical practitioners and consumers will certainly have consequences. Most of the consumers (112/227 respondents) indicated that they always completed a course of antibiotics. Forty-nine respondents indicated that they had already used antibiotics and that the therapy was unsuccessful. Antibiotic residues are still present so the risk to the consumer is still viable. Improved sampling and monitoring at abattoirs both for local and export abattoirs is necessary. The “farm to fork” concept and financial incentives by way of subsidies for residue-free products is a positive step. South African consumers are not quality conscious and further studies are necessary to improve the quality and safety of meat.

Some metals and metalloids make significant contributions to the harmful effects of tobacco consumption although understanding the mechanisms involved in toxicity is hampered by the lack of information on their chemical and valence species, both in tobacco and in smoke. This research addresses the speciation of the metals and metalloids most frequently implicated, particularly those elements that exist in nature in multiple valence states, namely arsenic (As) and chromium (Cr), there being considerable differences in toxicity with oxidation state. A strategy was devised to overcome some of the problems that have thwarted earlier attempts at speciation. Firstly tobacco plants were cultivated under controlled conditions in compost burdened with high levels of metals and metalloids resulting in leaf with up to 250 µg g⁻¹ As, although Cr uptake was less successful. Secondly valence speciation even at the exceptionally low concentrations of As and Cr in smoke from unburdened tobacco was achieved with XANES analysis using the exceptionally bright Diamond synchrotron source. This revealed that combustion of tobacco has a marked effect on valence speciation with As(III), the reduced form of As, dominating (and persisting) in condensate of tobacco smoke while ash is dominated by the oxidised form, As(V). Chromium also appears to be present in smoke mainly as reduced Cr(III) species. HPLC-ICPMS analysis of arsenic indicates the dominance of inorganic over organic species (~4:1). Other metals were investigated in less detail. These findings establish that arsenic is present in smoke in its most toxic form and represents a significant risk to health. Conversely smokers appear to be exposed to the less harmful species of chromium. These results support a recent WHO report that includes As but not Cr in a list of four metals and metalloids recommended for regulation in crops and commercial products in the interests of public health.

Thesis (MScPhysio)--Stellenbosch University, 2015 / ENGLISH ABSTRACT: Background: The use of computers at school, university, work and for social media is growing and whilst neck pain is common in the general population, computer users have an even higher prevalence. Incorrect workstation ergonomics have been identified as a risk factor for the development of neck pain in computer workers. Aims: To assess the effect of adjusting chair and monitor height of a female office worker’s computer workstation on work related neck and upper back pain intensity, comfort of her sitting posture and disability. Methods: An N=1 study was conducted using the A-B-C design consisting of a computer workstation adjustment involving chair and monitor height of a female office worker. The effect of the intervention was evaluated using the Visual Analogue Scale (VAS) to measure neck and upper back pain intensity and comfort of sitting position, and the Neck Disability Index to measure disability. The effect of the intervention was assessed over the three phases, consisting of four weeks each. During these phases, the participant could continue with her usual computer work. The results were compiled and tabulated. Results: A reduction in neck and upper back pain intensity as well as an increase in sitting comfort position were found. However these improvements were not statistically or clinically significant. The effect size for pain intensity was 0.76 and for sitting comfort 0.21. The participant reported no disability as measured by the Neck Disability Index, at the start and at the end at the end of the study. Conclusion: The vertical adjustment of this female office worker’s chair and monitor height according to her anthropometrics improved neck and upper back pain intensity and comfort of sitting position. This ergonomic workstation intervention could form part of a practical management option for computer users with neck and upper back pain. Further research is recommended to establish whether these findings are generalizable to the wider community of computer users. / AFRIKAANSE OPSOMMING: Probleemstelling: Die gebruik van rekenaars by skole, universiteite, werksplekke en vir sosiale doeleindes neem toe. Nek pyn kom dikwels in die algemene bevolking voor, maar dit is meer prevalent in rekenaargebruikers. ‘n Werkstasie wat nie ergonomies korrek opgestel is nie, is geidentifiseer as ‘n risikofaktor vir die ontwikkeling van nekpyn in rekenaar werkers. Doelwitte: Om te bepaal of aanpassings in die stoel- en beeldskerm hoogte van ‘n vroulike kantoor werker se rekenaar werkstasie, ‘n effek het op werksverwante nek en boonste rug pyn, sitgemak en funksionele vermoë. Methode: Die N=1 studie met ‘n A-B-C ontwerp is onderneem en het bestaan uit n rekenaar werkstasie aanpassing waarby die hoogte van die stoel en beeldskerm van ‘n vroulike relenaargebruiker aangepas is. Die effek van die intervensie is ge-evalueer deur middle van die visueel analoogskaal (VAS) om pyn en sitgemak te bepaal; en die Nek Ongeskiktheids Indeks (NOI) om gestremtheid te bepaal. Die effek van die intervensie is oor drie fases, wat elk bestaan het uit vier weke, evalueer. Gedurende die fases, kon die deelnemer met haar gewone rekenaarwerk voortgaan. Die resultate is saamgestel en getabuleer. Resultate: Daar was ‘n vemindering in die intensiteit van nekpyn, boonste rug pyn en die sitgemak van die individu het ook verbeter. Hierdie verbeteringe was egter nie statisties of klinies betekenisvol nie. Die effek grootte vir pyn intensiteit was 0.76 en vir sitgemak was 0.21. Die deelnemer het geen gestremdheid gerapporteer, soos gemeet met die NOI met aanvangs van die studie of teen die einde van die studie nie. Gevolgtrekking: Die vertikale hoogte-aanpassing van die stoel en beeldskerm van hierdie vroulike rekenaar werker volgens haar antropometrie het bygedra tot ‘n verbetering in nek en boonste rug pyn, asook sitgemak. Hierdie ergonomiese werkstasie intervensie kan deel vorm van die praktiese hantering van nek en boonste rug pyn in rekenaargebruikers. Verdere navorsing wod aanbeveel om te bepaal of hierdie bevindinge veralgemeenbaar is na die wyer gemeenskap van rekenaarverbruikers.

Poor semen quality is an indicator of male infertility and is also associated with a variety of adverse health outcomes in men. It is therefore important from both clinical and public health perspectives to discover predictors of poor semen quality, especially those that are potentially modifiable. My dissertation research focuses on two of these potential risk factors: adiposity and stress. Unlike most studies to date, which have only considered the relationship between these exposures and semen quality cross-sectionally, my research takes a life course approach. I explore associations between birth weight, adiposity in both childhood and adulthood, and allostatic load—a construct representing the effect of cumulative stress on the body’s regulatory systems—and three commonly-used semen outcome parameters: sperm concentration, percent progressive motility, and percent normal morphology. The logic that underlies this approach is that while sperm are constantly being produced from sperm stem cells in the testes, which would argue in favor of cross-sectional studies, the sperm stem cells themselves and the Sertoli and Leydig cells that stimulate and nurture that metamorphosis are laid down in the fetal period and undergo important developmental and proliferative phases during early childhood and puberty that affect their number and functional health in adulthood. Using data from 193 participants in the Study of the Environment and Reproductive health follow-up to the Child Health and Development Studies birth cohort, I was able to calculate birth weight for gestational age percentile (bw/ga) and six age-appropriate adiposity measures (at 4 months, 12 months, and 4 years, and in participants’ 20s, 30s, and at the time of semen collection), then test for their independent, critical period, and cumulative associations with the three semen outcomes as well as a combined outcome measure of subfertility based on World Health Organization reference levels. While bw/ga was positively associated with sperm concentration, subsequent childhood adiposity measures showed increasingly negative associations, and none of the adult measures were significantly associated with concentration. By contrast, only adult measures were associated with motility and morphology. This suggests that there may be critical periods in childhood when adiposity negatively affects sperm concentration by interfering with the development and proliferation of Sertoli and Leydig cells. Accumulation of oxidative stress in the testes due to overweight/obesity may explain the negative relationships between adult adiposity and sperm motility and morphology. To investigate allostatic load’s relationship to semen quality, I conducted a pilot study at Columbia University’s Center for Women’s Reproductive Care that enrolled 61 men who were having their initial diagnostic semen analysis and blood draw on the same day. Blood samples were analyzed for 7 biomarkers associated with homeostatic regulation across several physiologic domains. I then created an allostatic load scale in which participants were assigned 1 point for being in the high-risk quartile for systolic blood pressure, diastolic blood pressure, body mass index, or any of the biomarkers. In regression analyses, allostatic load was not associated with either sperm concentration or morphology, but showed an unexpected positive association with motility. This association was entirely driven by the six participants who scored 0 on the allostatic load scale and who did not differ from the rest of the sample in any way that could plausibly be linked to reduced motility. I therefore concluded that this was a spurious finding. In further analysis of the allostatic load variable itself, I found that few of its individual components were correlated with the semen outcomes. This contrasts with other studies of allostatic load and adverse health outcomes, but these have generally been conducted in either elderly or stressed populations, neither of which described my cohort. Allostatic load may not be a reliable measure of stress in reproductive age populations and may not capture regulatory systems appropriate to reproductive health outcomes. My dissertation highlights the value and challenges of conducting semen quality research from a life course perspective. Future studies should consider collecting longitudinal data on adiposity and stress, as well as repeated semen samples beginning in adolescence in order to further our understanding of the natural progression of semen quality across the reproductive life span and provide the opportunity to explore whether modifying these risk factors affects semen quality.