<p>It was hypothesized that South African FA and brine could sequester CO2 through mineral carbonation. A statistical approach was undertaken to optimize the % CaCO3 formed from FA/brine/CO2 interaction with input parameters of temperature, pressure, particle size and solid/liquid ratio (S/L) being varied. The ranges adopted for the input parameters were: temperature of 30 &ordm / C or 90 &ordm / C / pressure of 1 Mpa or 4 Mpa / four particle sizes namely bulk ash, &gt / 150 &mu / m, &lt / 20 &mu / m and 20 &mu / m- 150 &mu / m particle size range / S/L ratios of 0.1, 0.5 or 1. The FA/ brine dispersions were carbonated in a high pressure reactor varying the above mentioned input parameters. The fresh Secunda FA of various size fractions was characterized morphologically using scanning electron microscopy, chemically using X-ray fluorescence and mineralogically using qualitative X-ray diffraction. The carbonated solid residues on the other hand were characterized using quantitative X-ray diffraction, scanning electron microscopy, thermal gravimetic analysis and Chittick tests. The raw brine from Tutuka together with the carbonation leachates were characterized using inductively coupled mass spectrometry and ion chromatography. Total acid digestion was carried out to evaluate the differences in the total elemental content in both the fresh ash and the carbonated solid residues. The results suggested that South African FA from Secunda belongs to class F based on the CaO content as well as the total alumina, silica and ferric oxide content, while the RO brine from Tutuka were classified as NaSO4 waters...</p>

<p>This qualitative study was conducted from June to November 2009, using designed questionnaires for sixty three (63) registered students and five (5) HIV program staff .The main reason for this study was to understand the underlying factors for why students may utilize or may not utilize the available HIV services on campus. The willingness of students to express their views was a positive finding in this study. Majority students who answered the questionnaires were quite aware of these HIV services. They also agreed that services provided are good. The study also found out that females utilized these services more than males and majority of students learnt of the HIV services from the HIV programs pamphlets and website thus indicating that the HIV program at UWC is function. However the research study also found out that the though students are aware of these services few utilize them and majority are females thus leaves a question why males do not utilize.</p>

Only 12% of the patients died at home. When the period between diagnosis and death was less than one month, every patient died in an institution. Younger patients, married patients, and those living within the 40 km radius of the hospital utilized more hospital days. The "length of terminal hospitalisation" and the "proportion of days at home/ total inclusion days" seemed to be feasible outcome varibles when evaluating a palliative support service. The hospital-based palliative support service in this study defrayed its own costs due to a median saving of 10 hospital days/patient, compared with matched historical controls. A 19-item quality of life questionnaire (AQEL) was developed which evidenced good signs of reliability and validity. The item most closely correlated to global quality of life was the sense of meaningfulness. This was true for both patients and their spouses. Patients´ levels of pain and anxiety did not increase at the end of life. In this study we could not find convincing evidence for an additive analgesic effect of paracetamol in morphine therapy of pain in cancer patients.

Seagrass beds cover large intertidal and subtidal areas in coastal zones around the world and they are subjected to a wide variety of anthropogenic influences, such as nutrient enrichment due to sewage seepage. This study was undertaken to address specific questions focusing on whether near shore tropical seagrasses that receive a constant influx of groundwater nutrient inputs, would exhibit a higher productivity and to what extent epiphytic algae reflect the impacts of nutrient inputs. An additional aspect of study was to determine the prevalence of “acid zones” in tropical seagrasses. The productivity of the seagrasses Cymodocea rotundata, Thalassia hemprichii and Thalassodendron ciliatum was compared in two sites along the Kenyan coast; Nyali (a high nutrient site) and Vipingo (a low nutrient site). Of the three seagrasses T. hemprichii showed the most distinct differences with higher growth and biomass in the nutrient rich site whereas the growth of C. rotundata was similar in the two sites. A high epiphytic cover was found on the shoots of T. ciliatum found in the high nutrient site Nyali. Morphological and genetic characterization of bacterial and cyanobacterial epiphytes showed specific associations of nitrogen fixing cyanobacteria on the seagrass C. rotundata in the low nutrient site (Vipingo). At this site, shoots of C. rotundata had a higher C:N ratio compared to shoots in the high nutrient site (Nyali) indicating that the association with nitrogen fixing cyanobacteria is a strategy, for this species, to meet its nutrient needs. Bacterial epiphytes belonging to the group Cytophaga-Flavobacteria-Bacteroides (CFB) were found on T. ciliatum and T. hemprichii from the two sites. CFB bacteria are characteristic of waste water, particularly from livestock farming areas, thereby confirming seepage of groundwater from surrounding catchment areas. These prokaryotic associations were specific for the different seagrasses and it appears that the establishment of epiphytic associations may not be a random encounter but a specific association that meets specific needs. The seagrass T. ciliatum in the high nutrient site had an abundance of macroalgal epiphytes and the impact of the epiphytic coverage was assessed using Pulse Amplitude Modulated (PAM) fluorometry. The photosynthetic activity of seagrass parts that were covered by epiphytes was suppressed but the productivity of the whole shoot was not significantly reduced. In the nutrient rich site, epiphytes were found to contribute up to 45% of the total estimated gross productivity, during the SE monsoon season, while epiphytic contribution in the nutrient poor site, was 8%. Epiphytic abundance and contribution to productivity decreased during the NE monsoon. The photosynthetic activity of T. ciliatum shoots was similar in the two study sites with shoots in the nutrient rich site growing faster. T. ciliatum, in the low nutrient site, invested in the development of below ground root tissue which may indicate the development of a strategy to gain access to pore water nutrient pools. Carbon uptake strategies of eight tropical seagrasses were re-evaluated to determine how common the “acid zone” mechanism is among tropical seagrasses. Six of the eight species studied showed photosynthetic inorganic carbon (Ci) acquisition based on carbonic anhydrase catalysed HCO3- to CO2 conversions within an acidified diffusion boundary layer (“acid zone”). Cymodocea serrulata appeared to maintain its carbon uptake by extracellular carbonic anhydrase catalysed CO2 formation from HCO3- without the need for acidic zones, whereas, Halophila ovalis appeared to have a system in which H+ extrusion may be followed by HCO3--H+ co-transport into the cells. These findings indicate that competition for carbon, between the host seagrass species and epiphytes, could determine seagrass-epiphyte associations.

One of the most vulnerable groups in Swedish society today is single parent families, a group that has increased over the last thirty years in proportion to married and cohabiting parents. The aims of this thesis are to study inequality and inequity in health and health care utilization with regard to whether parents are single or couple (married/cohabiting), to investigate whether the concept of social capital may provide us with further understanding when analyzing inequality and inequity in health and to investigate how the mental health of single parent children may differ from couple parent children and to what extent this difference may be due to parental socio-economic and socio-demographic characteristics, including social capital. The results from the papers on which this thesis is based indicate that both single mothers and single fathers have poorer health than couple mothers and fathers. Single mothers also refrain from seeking medical care to a greater extent. The financial advantage of single fathers, in comparison with single mothers, might have an impact on their medical care utilization, since they seemingly seek and consume health care to an extent that matches their poorer health. Social capital has as robust an association with self-rated health as any traditional social determinant of health. Four parental characteristics were found to be independently associated with children’s mental health; being a single parent, ‘poor parental health’, limited social support and low levels of social capital. The uneven distribution of all investigated determinants of health, including social capital, gives us reason to conclude that our findings indeed raise concerns about equity. Action taken by society to enable single parents to increase their social capital might improve their and their children’s health. It may also be clearly stated that financial status has a major impact on both health and health care utilization. This particular characteristic is also rather accessible to alteration, for example through financial transfers between groups in society.

Chronic diseases place a substantial economic burden on the health care system. Physical inactivity, poor diet and smoking are considered to be the main causes of high rates of chronic disease. Evidence clearly supports the positive influence of physical activity on health determinants, other health outcomes and quality of life. This implies that an increase in physical activity improves general health status and has the potential to reduce utilization of expensive healthcare services and disability days. Earlier studies show that physical activity programs would be an effective way of providing preventive care for people with chronic conditions. However studies that relate physical activity programs to health care utilization are limited in economics literature.<p>The aim of this paper is to examine the impact of physical activity programs on healthcare utilization. From 2002 to 2003, adults over the age of 50 years, in a mid-size Canadian city, presenting with excess weight, type 2 diabetes, hypertension, hyperlipidemia or osteoarthritis were recruited. Following a screening process, eligible participants were randomly assigned to one of two programs: a class-based structured program or a home-based unstructured program. Validated questionnaires related to health status and quality of life were completed and physical tests were carried out at baseline, 3, 6, 12 months and 24 months after the program initiation. In addition participants use of physician and hospital services and pharmaceutical expenditures were accessed through their administrative data files for three years, one year before and two years after the intervention. Using administrative data from Sask Health and individual level survey data the effects of physical activity programs on health care utilization were estimated. The results showed that structured physical activity program can reduce annual physician costs significantly. The exponential effect of aging was found to be significant on hospital utilization, and the number of comorbidities was found to be significant on prescription drug utilization.

Two studies were devised to determine why the difference in manual aiming performance, between full vision and no vision, is decreased for a randomized visual feedback schedule. In study one, aiming accuracy and precision was assessed for up to four trials in the same vision condition, following a switch in visual feedback availability. In experiment one, visual feedback availability was uncertain; while in experiment two, certainty was provided. Results of both experiments revealed that the precision of the first trial immediately following the switch in visual condition was reminiscent of the trial that preceded it, even when performed under different visual conditions. For study two, the inter-trial interval was evaluated by extending the interval to five seconds. Results indicated no reminiscence effect. Overall, we suggest that when the inter-trial trial is brief, individuals rely on offline visual information from the preceding trial to plan the subsequent movement, regardless of certainty.

Two studies were devised to determine why the difference in manual aiming performance, between full vision and no vision, is decreased for a randomized visual feedback schedule. In study one, aiming accuracy and precision was assessed for up to four trials in the same vision condition, following a switch in visual feedback availability. In experiment one, visual feedback availability was uncertain; while in experiment two, certainty was provided. Results of both experiments revealed that the precision of the first trial immediately following the switch in visual condition was reminiscent of the trial that preceded it, even when performed under different visual conditions. For study two, the inter-trial interval was evaluated by extending the interval to five seconds. Results indicated no reminiscence effect. Overall, we suggest that when the inter-trial trial is brief, individuals rely on offline visual information from the preceding trial to plan the subsequent movement, regardless of certainty.

Information systems are designed to support human and organizational purposes. To achieve their ends, information systems must be used. Although this may seem to be self-evident, there are many aspects of systems usage that are not so, and yet, in spite of this, there has been little intense conceptual scrutiny of this construct in past research. The objective of this thesis, therefore, is to develop new in-depth perspectives for studying system usage. Drawing on critical realist assumptions and studies of research diversity, I explain how epistemological factors enable while ontological factors constrain the diversity of meanings of system usage, and I build on this reasoning to advance a systematic approach for conceptualizing and measuring system usage in an appropriate way for a given research context. To demonstrate the approach and judge its usefulness, I carry out three empirical studies to test whether measures of system usage that are selected according to the proposed approach provide more explanatory power and lead to more coherent results in specific research contexts than other measures of system usage. Exploring the relationship between system usage and user task performance among 804 users of spreadsheet software, the experiments reveal support for the usefulness of the approach and demonstrate how it can enable researchers to conceptualize and measure system usage in an appropriate manner for a given research context. Together, the conceptual approach and empirical studies contribute by: (1) providing a systematic way to conceptualize and measure system usage for a given study context, (2) revealing rich new directions for research on the nature of system usage, its antecedents, and its consequences, and (3) suggesting a new approach for construct development and investigation in IS research.

Alcohol abuse during pregnancy has been associated with Fetal Alcohol Spectrum Disorder (FASD). Research to date has focused on the role played by ethanol in the development of this disorder. In addition to ethanol, alcoholic drinks also contain methanol. Hence, consumption of alcohol can also lead to methanol accumulation. Methanol is metabolized to formaldehyde, which is then rapidly metabolized to formate, a toxic metabolite. Folate, a B-vitamin and antoxidant, is a cofactor in the metabolism of formate. This study assessed the relationship between formate and folate, formate kinetics in folate deficiency and, changes in antioxidant capacity during formate insult in folate deficiency. The findings of this study would lead to a better understanding of the role of formate in the development of the etiology of FASD and form the basis of future research. The relationship between formate and folate was investigated in intoxicated human female subjects, sober drug rehabilitating females and, pregnant women. A negative (inverse) relationship was observed between plasma formate and folate in pregnant sober women (correlation coefficient = -0.4989). Such a relationship, however, was not observed in whole blood in alcohol intoxicated (correlation coefficient = 0.0899) and detox women (correlation coefficient = 0.2382). Because of the health promoting ingredients in grain and fruit based alcoholic drinks, antioxidant B-vitamins were higher during intoxication while homocysteine levels were lower.<p>Formate kinetics during folate deficiency and changes in the body antioxidant capacity was investigated in folate deficient young swine. Folate deficiency altered formate kinetics leading to decreased systemic clearance (by approximately 2.3 fold), increased half-life (by 2.5 fold) and, consequently increased exposure (by 2.7 fold). Folate deficiency alone compromised antioxidant capacity. However, the combination of folate deficiency and formate insult further compromised antioxidant capacity.<p>In conclusion, methanol accumulates after alcohol intoxication, which can lead to formate build up in the body. During folate deficiency formate kinetics is altered leading to reduced formate clearance and increased exposure. Exposure to formate coupled to folate deficiency compromises antioxidant capacity, which can have deleterious effects on the fetus.