Thesis (MScEng)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: South Africa is a relatively dry country with an annual average rainfall of 464mm compared to a world average of 860mm (WSA, 2009). Water shortages and droughts are fairly common to the western and high lying of regions South Africa. Due to its population growth and the rapid development, like the rest of the world, there has been an increased demand for water. Due to increasing costs of procuring water and its decreasing availability, the option of using seawater as a source for freshwater or directly in industrial processes has become competitive, especially in the arid parts of the world. The design of seawater intakes forms an integral part of providing a secure source of seawater. The objective of this thesis is to aid in the development of guidelines for the design of small scale seawater abstraction systems on rocky coastlines using the Horizontal Well Method. Recommendations for guidelines will be given. / AFRIKAANSE OPSOMMING: Geen opsomming

2 pp. / [Healthy Fats -- Guide for Improving the Quality of Fat Intake] / The fact sheet reviews healthy fats and how to incorporate a healthy amount of fat into our diet. Fats are necessary for our bodies to function properly. In fact, fats are an important part of a healthy diet and we can't live without them. Fats can be grouped into two groups: saturated and unsaturated. Unsaturated fats include polyunsaturated and monounsaturated fats. Both these fats, when eaten in moderation and used in place of saturated and trans fats, can help lower cholesterol levels and decrease the risk of heart disease. We provide a list of "Do's" and "Tips" which gives examples of how to select fats wisely and incorporate healthy changes into our diet. We also provide a guide for selecting an appropriate portion size of fat.

2 pp. / The fact sheet reviews healthy fats and how to incorporate a healthy amount of fat into our diet. Fats are necessary for our bodies to function properly. In fact, fats are an important part of a healthy diet and we can't live without them. Fats can be grouped into two groups: saturated and unsaturated. Unsaturated fats include polyunsaturated and monounsaturated fats. Both these fats, when eaten in moderation and used in place of saturated and trans fats, can help lower cholesterol levels and decrease the risk of heart disease. We provide a list of "Do's" and "Tips" which gives examples of how to select fats wisely and incorporate healthy changes into our diet. We also provide a guide for selecting an appropriate portion size of fat.

Leptin is an adipokine that acts centrally to regulate feeding behaviour, energy expenditure and autonomic function via activation of its receptor (ObRb) in nuclei in the central nervous system (CNS). This thesis investigates the involvement of two sensory circumventricular organs (CVOs), the subfornical organ (SFO) and area postrema (AP), in mediating the central effects of leptin using a variety of experimental approaches. We first show that acute electrical stimulation of the SFO elicits feeding in satiated rats, supporting a role for this specialized CNS structure in the control of food intake. We then demonstrate, using RT-PCR, the presence of ObRb mRNA in SFO and, using whole cell current clamp electrophysiology, reveal that leptin influences the excitability of individual SFO neurons, causing both excitatory and inhibitory responses. Furthermore, we find that leptin activates the same SFO neurons activated by amylin. Given the association between obesity and hypertension and the well-established role of the SFO in cardiovascular regulation, we show that leptin microinjection into the SFO decreases blood pressure in young rats, effects that are abolished in leptin-resistant, diet induced obese rats, suggesting that leptin-insensitivity in the SFO of obese, leptin-resistant, individuals may contribute to obesity-related hypertension. Our studies also show that the medullary AP expresses ObRb and that leptin influences the excitability of AP neurons. Furthermore, we show that leptin and amylin act on the same subpopulation of neurons in the AP. Finally, our preliminary AP/SFO lesion studies reveal that animals with these lesions exhibit a profound decrease in body weight and food intake and no longer exhibit decreases in body weight in response to peripheral leptin administration. In summary, the data presented in this thesis suggest the SFO and AP to be important in body weight homeostasis and in mediating the central effects of leptin. In addition, these areas appear to be important in the integration of multiple signals derived from peripheral sources. Furthermore, the fact that the SFO appears to be involved in leptin effects on both energy balance and cardiovascular regulation attest to the integrative nature of the SFO in the control of diverse physiological functions. / Thesis (Ph.D, Physiology) -- Queen's University, 2012-10-15 14:57:15.387

The Ontario Clean Water Act (2006) mandated that eight and two municipal drinking water intakes in the Cataraqui Region Conservation Authority (CRCA) and the Ganaraska River Source Protection Agency (GRSPA) jurisdictions respectively, be protected from contaminants released into the surrounding waters through the delineation of Intake Protection Zones (IPZs). Toward these objectives, the Estuary and Lake Computer Model (ELCOM) was applied to simulate the hydrodynamics and contaminant transport in the eastern Lake Ontario and upper St. Lawrence River. Model hydrodynamics were comprehensively validated against field data collected during April-October, 2006. The flow was found to be predominantly wind induced in the southwestern lacustrine portion of the domain and hydraulically driven in the northeastern riverine portion with storm events resulting in river flow reversals. The modeled surface currents were applied to delineate IPZs surrounding the drinking water intakes. Passive tracers were simulated as surrogates for combined sewer outflows, tributary flows, municipal/wastewater and industrial discharges identified by CRCA as threats to drinking water intakes. Wind was found to be the most dominant forcing to transport contaminants, both in the Kingston Basin and the St. Lawrence River, whereas the St. Lawrence River outflow was found to influence the transport of contaminants along the river. The hydrodynamics and contaminant transport in the near-shore region of Lake Ontario, from Port Hope to Cobourg was also simulated using ELCOM and the results were comprehensively validated against field data collected during April-September, 2010. Upwelling and downwelling events caused by south-westerly and north-easterly winds were found to be the predominant hydrodynamic process. These events generated barotropic geostrophic alongshore currents or ‘coastal jets’ of ~20 cm s-1. Discharges from river plumes and sewage treatment plants were simulated as tracer releases. The tracer concentrations were primarily influenced by the close proximity of the intakes to the effluent release points, the volume and direction of the discharge from the intakes and the physical processes driving the flow dynamics. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2013-07-17 11:41:54.68

It is estimated that over 30 million people are exposed to arsenic from drinking contaminated groundwater in Bangladesh. Furthermore, due to the use of contaminated water for irrigation purposes, arsenic and other toxic elements are entering the food chain of Bangladeshis. In this thesis, the total levels of toxic elements (As, Cd, Pb) and essential elements (Mn, Se, Zn) in 1,120 samples of Bangladeshi foods (including rice, vegetables, fish) and non-foods (betel quid and baked clay) imported into the United Kingdom were determined. From this analysis, it is concluded that Bangladeshis are exposed to high levels of toxic elements. Inorganic arsenic levels in Bangladeshi rice can be very high, especially from regions with high arsenic in groundwater. However, there is a lack of studies in the literature regarding arsenic levels in rice from regions in Bangladesh with relatively low levels of arsenic in the groundwater. Therefore, rice from one such region (Sylhet district) was analysed. The results indicated that boro (mean 71.7 µg/kg) and aman (mean 85.7 µg/kg) rice from Sylhet contained between 2 to 4-fold lower levels of arsenic, compared to other regions of Bangladesh thus far reported in the literature. Arsenic speciation was carried out on a selection of rice (aromatic and non-aromatic) from Sylhet region and this revealed 70% (mean value) as inorganic arsenic (AsIII and AsV), which is similar to rice grown in other regions of Bangladesh. Importantly, it was found that the arsenic levels of aromatic rice (mean 48.5 µg/kg) from Sylhet region was over 40% lower than that of non-aromatic rice (mean 81 µg/kg). The aromatic rice also contained higher levels of essential elements (such as Se and Zn). It was calculated that for an individual consuming 0.5 kg of rice per day, switching from consumption of non-aromatic rice to aromatic rice would increase Se and Zn intake by 46% and 23% respectively. Arsenic speciation was also carried out on other Bangladeshi food and non-food items, including fish, betel quid and baked clay, to obtain a better insight into exposure to toxic arsenic species. High levels of arsenic (range 3.8-13.1 mg/kg) and lead (range 21-26.7 mg/kg) were detected in the baked clay samples, which are consumed by some Bangladeshi women in an ancient practice known as geophagy. The efficiency of arsenic extraction from baked clay was 33% of the total arsenic present and the main arsenic species present was inorganic AsV (100%); AsIII was not detected in these samples. Millions of Bangladeshis chew betel quid and this contained predominantly AsIII species (extraction efficiency was 100%). Arsenic and lead intake from eating baked clay could exceed the provisional maximum tolerable daily intake (PMTDI) by 2- and 5-fold respectively. For the first time, arsenic speciation in Bangladeshi fish is reported. Hilsha, which is a very popular fish in Bangladesh, contained 2.55 mg/day (mean value) of total arsenic. Extraction efficiencies (%) were 59 – 89 for fish flesh, over 69% of arsenic present in the extract was dimethyl arsenic acid (DMA) species with about 11% arsenobetaine (AsBet) and 19% arsenosugar. These studies reveal that rice, betel quids and baked clay can be a significant source of exposure to inorganic arsenic and DMA in Bangladeshis. Exposure to cadmium is linked with kidney disease and over 20 million people in Bangladesh suffer from chronic kidney disease. Results obtained showed that the daily intake of cadmium by the Bangladeshi population from baked clay (mean 17 µg/day), rice (mean 18.6 µg/day) and certain leafy vegetables (mean 12 µg/day) was higher total daily intake compared to other countries. Surprisingly, puffed rice, which is commonly consumed by Bangladeshis, contained much higher levels of cadmium (mean 67.9 µg/kg) and lead (mean 98 µg/kg), compared to uncooked rice (cadmium, 37.2 µg/kg; lead, 18.9 µg/kg). This may be related to the illegal practice of using urea for whitening puffed rice in Bangladesh. Exposure to manganese in the Bangladeshi population through drinking water has been previously highlighted as a possible health problem, although the intake from foods and non-food has not been reported. The daily manganese intake by Bangladeshis was calculated to be 20.3 mg/day, which is higher than any other country in the world thus far reported. Betel quid components have high levels of manganese and this was reflected by higher urinary manganese the mean urinary Mn levels in chewers (1.93 µg/L, SD 1.8) was significantly higher (3.1 fold; P = 0.009) compared to non-chewers (0.62 µg/L, SD 0.4). Bangladeshi women who eat baked clay and chew betel quids are likely to be exposed to high levels of arsenic, lead and other toxic elements. This is particularly of concern for pregnant women as these metals can be transferred to the unborn baby through the placenta. For assessing the risk of exposure to toxic elements versus intake of essential elements from the same foods, a Food Toxicity Scale (FTS) was devised in order to identify foods that are beneficial or harmful. FTS values were obtained by calculating the toxic elements : essential elements ratio (As:Se, As:Zn etc) and the value obtained subsequently multiplied by toxic element concentration and the quantity of the particular food consumed per day. The higher the FTS value, the greater the risk of exposure to harmful elements. Rice and leafy vegetables had the highest FTS values, partly because large quantities of these foods are consumed. However, lentils and animal products (such as small fish) had relatively lower FTS values compared to other foods. Total daily intake of arsenic (306 µg/day), selenium (90.4 µg/day), cadmium (34.6 µg/day), lead (74.4 µg/day), manganese (20.3 mg/day) and zinc (11.2 mg/day) in the Bangladeshi population was calculated. The intake of arsenic and manganese exceeds the PMTDI for these elements. Water was the highest source of arsenic exposure in Bangladeshis followed by rice. For cadmium and lead, rice and leafy vegetables were the key contributors to the daily intake. The results presented in this thesis show that Bangladeshis are exposed to high levels of toxic elements and how modifications can be made to their diet to not only reduce their exposure to toxic elements but also increase the intake of essential elements. This could be achieved by a combination of the following: (i) reducing the intake of rice (by about 50%); (ii) switching to eating aromatic rice; (iii) increasing the intake of animal products (meat, fish etc.); (iv) decreasing the intake of certain leafy vegetables; and (v) stopping or reducing the practice of eating baked clay and chewing betel quid.

Adequate fluid consumption is central to human survival. Previous literature suggests that there some misconceptions regarding hydration and fluid balance in some populations. Available data also show that the role of thirst sensations in maintaining fluid balance in different settings is also equivocal. Therefore, this thesis aimed to examine the perception of hydration, thirst and fluid intake in freeliving populations, to examine the feasibility of thirst as a marker of hydration status and to investigate the effect of thirst related sensations on fluid balance in resting and exercising individuals under different ambient temperatures. The findings in this thesis (Chapter 3) show that individuals who work within the fitness industry demonstrated substantial knowledge about drinking practices, hydration status and health consequences of water consumption, but lack understanding on the type of beverages that adequately hydrate the body. Further, thirst perception and mood states did not affect (P>0.05) the fluid intake in free living individuals (Chapter 4) and resting individuals under cool and warm exposure (Chapter 6), but some other factors such as subjective feelings of mouth dryness and the extent of hydration status might influence the fluid intake behaviour in these populations. In addition, following ingestion of flavoured carbohydrate drinks, thirst sensations was rated lower over time (P<0.05) during exercise in the cool, but was higher over time in the warm temperature (Chapter 7). Moreover, subjective feelings related to dehydration such as mouth dryness, thirst perception, desire to drink (water pleasantness) and hunger rating could be used as index of hydration status to signify at least a 1% body mass loss due to food and fluid restriction in resting individuals (Chapter 5). In conclusion, the findings in this thesis provide some new insight with respect to hydration, thirst and fluid balance in different populations under different settings. Nevertheless, some inconclusive findings regarding the role of thirst related sensations in fluid balance require further investigations.

Objectives. This study aimed to provide data on water intake from food and beverages of free-living adults in their natural environment, and investigate how this is affected by physiological, psychological, social and environmental factors. A further aim was to monitor the hydration status of free-living adults and relate this data to water intake. Methods The consumption of all food and beverages was recorded in a diary over three consecutive days by 80 healthy adults (40 males, 40 females), aged 18 to 65 years, who were instructed to continue their normal eating and drinking habits and lifestyles throughout the study. The data was analysed to determine total daily water intake and how this was affected by time of day, day of the week, presence of others, location of consumption, age and subjects mood. A further 20 healthy subjects (10 males, 10 females) repeated these procedures but also had blood samples taken for monitoring of blood indices (haemoglobin concentration, haematocrit, sodium concentration, and potassium concentration) and provided urine samples for the measurement of urine indices (volume, colour, specific gravity, osmolality and sodium, potassium, chloride, and creatinine concentrations). Results The total volume of water consumed by the 80 subjects was 2229  882 ml/day (mean  standard deviation). Females tended to consume more water than males (2402  827 ml/day vs 2056  911 ml/day, P = 0.079). Similar volumes were consumed by the additional 20 subjects in the hydration status study. Females appeared euhydrated; males appeared mild dehydrated, having a higher morning and 24-hour urine specific gravity and osmolality than females (P < 0.05, respectively). Conclusions The mean daily total volume of water consumed by females in this study was greater than the adequate intake value set by the European Food Safety Authority; for males it was lower. Females were euhydrated during the study but males tended to be mild dehydrated, reflecting their comparative water intakes.

Background: Studies of assessing dietary fluoride intake in children have employed different dietary methods mainly “2-day duplicate” and “3-day food diary” methods. However, none of these methods have been validated or standardised. Main aims: The main aims of the current study were to develop a better understanding of strengths and weaknesses of dietary assessment methods “2-day duplicate plate” and “3-day food diary” by comparing dietary fluoride intake estimated by each method and evaluate the validity of the two methods for estimating dietary fluoride intake in young children. Methods: Sixty one healthy 4-6 year old children living in fluoridated area of the north-east of England since birth were recruited via 10 primary schools. Dietary information was collected using “2-day duplicate plate” and “3-day food diary” methods. Two 24-h urine samples and two samples of post brushing expectorate (a mixture of saliva, toothpaste and water used to rinse after brushing) from each child. Completeness of 24-h urine samples was checked using urinary excretion of creatinine and urinary flow rate. Validity of the two dietary assessment methods was checked by measuring urinary excretion of nitrogen and potassium as independent validity checks. Total daily fluoride intake from diet and toothpaste ingestion and urinary fluoride excretion was determined for each child. Results: All participated children completed all aspects of the study. According to the validity criteria, dietary data of 58 (95%) children, when collected by the 3-day food diary, were considered valid. However, when the dietary data were collected by the 2-day duplicate plate method, the data for 46 (75%) children were viewed as valid. Mean total dietary fluoride intake was 0.533 mg/d by the 3-day food diary method and 0.583 mg/d by the 2-day duplicate plate method. No statistically significant difference in total dietary fluoride intake was observed between the two methods. The mean difference in estimated dietary fluoride intake by the two dietary assessment methods was -0.050 mg/d with 95% limits of agreement of -0.501 to + 0.401 mg/d. Conclusion: Either the 3-day food diary or the 2-day duplicate plate method can be used when investigating mean total daily dietary fluoride intake of a population. However the methods cannot be used interchangeably at the individual level.

This research study was performed in an attempt to fill an apparent void regarding the relative utility and comprehensiveness of three published, theoretically-based, idiographic, initial assessment inventories: Integral Intake (II), Life-Style Introductory Interview (LI), and Multimodal Life History Inventory (MI). “Experts” -- defined as professors of counseling or psychology and licensed practitioners who have been practicing as counselors or psychologists for at least five years - read through the inventories and then evaluated them by responding to both (qualitative) open-ended questions as well (quantitative) rankings and ratings. The researcher posed three primary research questions: 1) how do participants' evaluations differ regarding the overall helpfulness of the three inventories; 2) how do participants' evaluations differ regarding the comprehensiveness -- both relative to each of the eight dimensions of the client (thoughts, emotions, behaviors, physical aspects of the client, physical aspects of the client's environment, culture, spirituality, and what is most meaningful to the client) and overall -- of the three inventories; and 3) how do participants' evaluations differ regarding the efficiency with which the three inventories assessed the eight dimensions. Results indicated that participants consistently evaluated the II and MI as more helpful, comprehensive, and efficient than the LI - both overall and relative to the eight specific dimensions. The LI was consistently evaluated as the worst of the three inventories -- on all dimensions. The MI was evaluated as the best inventory on four dimensions: the client's thoughts, emotions, behaviors, and physical aspects. The II was evaluated as the best inventory on seven dimensions: physical aspects of the client's environment, client's culture, client's spirituality, what is most meaningful to the client, and, notably, on overall comprehensiveness, overall efficiency, and overall helpfulness. Another goal of this research was to obtain feedback from the participants relative to how to improve the II. This goal was also accomplished and the researcher will implement this feedback into subsequent versions of the Integral Intake.