Thesis (M.H.A.)--University of Michigan, 1958.

Thesis (M.S. in Operations Research)--Naval Postgraduate School, September 2008. / Thesis Advisor(s): Fricker, Ronald D. "September 2008." Description based on title screen as viewed on November 5, 2008. E-BRARY Electronic Book Collection . Includes bibliographical references (p. 43-46). Also available in print.

Awareness of the importance of policy regarding the equitable distribution of global water resources is increasing. The purpose of this research study was to investigate the effects of allocation rules and drought conditions on allocation decisions through a decision experiment based on an idealized river basin that simulated conditions in the Saskatchewan River Basin. Participants took on the roles of water managers responsible for allocating water resources to four competing sectors in Alberta, Saskatchewan, and Manitoba. Three variations of allocation rules were tested: (a) status-quo allocation rules mimicking the current governance structure involving prearranged allocation rules across regions, (b) no predetermined rules, and (c) no predetermined rules but communication among participants. Each allocation rule was tested under two potential water levels: (a) drier-than-average conditions today reflecting 81% of historical flows, and (b) severe drought conditions with a 45% reduction from today’s flows. Results showed that policy had a significant effect on how participants allocated water resources, indicating that the absence of defined minimal flow rules and the lack of communication among riparian users resulted in less equitable distribution of water, with negative ramifications for downstream users. Additionally, results showed that drought-induced water scarcity significantly affected allocation patterns, with participants choosing to protect municipal water use at the expense of industry and agriculture in the face of water shortage conditions. For decision makers and water stakeholders in the Saskatchewan River Basin, these findings provide insight into the effectiveness of the 1969 Master Agreement on Apportionment to ensure the equitable distribution of water through defined minimum flows and the problem of fragmented governance, which prevents effective communication between upstream and downstream users. The findings also highlighted the importance of having a formal rule structure to oversee allocations or ongoing communication processes to facilitate problem solving in preparation for drought conditions.

The popularity of growers using only postemergence (POST) herbicides for weed management in soybean was enabled by the commercialization of glyphosate-resistant soybean. The efficacy and flexibility provided by this technology diminished the use of soil residual herbicides and arguably, increased soybean yield loss from early-season weed competition. While, the rapid evolution and biogeographical spread of herbicide-resistant weeds, especially glyphosate-resistant biotypes, has renewed interest into the use of soil residual products, herbicide-resistant soybean technologies continue to be developed that may once again entice growers into POST-only weed management systems. The commercial interest in soybean yield advancements justifies further characterizing the benefits provided by early-season weed control beyond those of herbicide-resistance management. Furthermore, as awareness heightens regarding techniques that will enhance the sustainability of agro-ecosystems, specific focus on resource utilization will help to evaluate the viability of this weed management strategy. Field experiments were conducted across four sites throughout southern Illinois in 2012 and 2013 to study the influence of early-season weed management strategies on soybean nutrient accumulation, grain yield parameters, and the acquisition of nutrients by broadleaved and grass weeds. Increasing periods of weed competition duration were established by removing weeds at heights of 10, 20, 30 or 45 cm with glyphosate. A weed-free treatment utilizing a comprehensive soil residual and POST herbicide program was included to implement a weed-free comparison. Two standard herbicide management strategies that simulate common grower practices were also evaluated for comparison: flumioxazin PRE followed by glyphosate POST and two sequential POST glyphosate applications. Averaged across all 11 mineral nutrients analyzed in this experiment, broadleaved weeds accumulated 149 and 108% more nutrients than grasses in 2012 and 2013, respectively. Competition from 20-cm weeds reduced the acquisition of N, P, Ca, Mg, S, Fe, B, Cu, and Zn by soybean in 2012; these nutrients in addition to K and Mn were reduced by the same level of competition in 2013. N and Fe were the nutrients in soybean most notably impacted by weed interference. Reductions in soybean grain yield were the result of competition with 30-cm weeds in 2012, and 10-cm weeds in 2013; while, both standard herbicide regimens yielded less than the weed-free treatment in 2013 only. Additionally in 2013, average soybean seed weight and grain oil content was reduced when weeds were not removed before a height of 10 and 20 cm, respectively. The rate of decomposition and nutrient release was measured for waterhemp and giant foxtail desiccated by glyphosate at heights of 10, 20, 30, and 45 cm in two southern Illinois soybean fields. Weed biomass was grown under greenhouse conditions to ensure homogeneity and litterbag methodology was utilized to track in situ mass and nutrient losses, expressed as a decay constant (k) regressed over time according to the single exponential decay model. The effect of specie and height both had a strong influence on the intrinsic properties of the weed biomass and the associated rate of decay. Concentrations of the recalcitrant cell wall components (cellulose, hemicellulose, and lignin) were generally greatest as weed height (plant age and development) increased and with giant foxtail compared with waterhemp. Ca, Mg, and S concentrations were greater in waterhemp, while N was greater in giant foxtail. N and K concentrations decreased with increasing weed height. After 16 weeks, 10-cm waterhemp and giant foxtail detritus had lost 10 and 12% more mass compared to the 45-cm height. Decomposition rates revealed mass loss was highest for 10-cm waterhemp (kD = 0.022) and lowest for 45-cm giant foxtail (kD = 0.011) and this process was negatively correlated to the overall amount of cell wall constituents (r = -0.73). Nutrient release rates followed a similar trend in that shorter (younger) weeds and waterhemp liberated nutrients more readily. Across all tested plant material, K was the nutrient most rapidly released, whereas, Ca was the most strongly retained nutrient. Although the pressing challenge of managing herbicide-resistant weeds justifies the implementation of early-season weed control tactics, this research suggests there are ancillary benefits that are provided by this strategy. The use of a robust, broad-spectrum soil residual herbicide program in conjunction with timely POST applications provides the foundation for early-season weed management, thereby minimizing non-crop nutrient use and enhancing the nutrient acquisition capacity in soybean. This strategy facilitates more sustainable crop production by requiring fewer supplemental nutritional inputs while also protecting grain yield.

Submitted in fulfillment of the academic requirement for the degree Doctor of Philosophy (Ph.D.) in Food Science and Technology, Durban University of Technology, Durban, South Africa, 2017. / Bambara groundnut (Vigna subterranea) is an indigenous underutilised leguminous crop to Africa. It is a good source of protein and carbohydrate including starch. Bambara groundnut is a traditional crop grown mainly for subsistence in Southern Africa. Bambara groundnut has the advantage of being drought tolerant and can thrive in hot temperatures and poor soil conditions. Therefore, it has great potential as an alternative crop to soya bean and peanuts for cultivation and utilisation. Bambara groundnut starch can potentially be used for various industrial applications. However, native starches are not suitable for most industrial applications, hence the need for modification. Bambara groundnut starch has been previously modified using physical and chemical modification methods. Natural alternatives such as the use of lipids are being sought to modify starches due to the associated risk with chemically modified starch. In this research, Bambara groundnut starch was modified with lipids to improve functional properties, utilisation and application. Specifically, the physicochemical properties of native Bambara groundnut starch obtained from five Bambara groundnut genotypes and three landraces (maroon, brown and cream) were determined. Bambara groundnut starch was modified with lipids (palmitic acid, stearic acid, oleic acid, linoleic acid and lysophosphatidylcholine) and the physicochemical properties of the modified starch were investigated. Further, the influence of high-pressure homogenization on complexation of Bambara groundnut starch with lipids was assessed in comparison with maize and potato starches. Lastly, an application of modified Bambara groundnut starch in biofilm production was also studied. Bambara groundnut landraces generally showed higher amylose contents (approx. 33%) than the genotypes (approx. 28%). Differences were observed in the crystalline patterns of these starches. Bambara groundnut genotypes exhibited the C-type-crystallinity, while the landraces showed the unusual A-type pattern. In terms of functionality, landrace starches showed better swelling than the genotypes. Subsequent studies on modification used maroon Bambara groundnut starch since the amylose content was higher than other landraces and there was a consistent supply of the grains during the period of the study. Generally, Bambara groundnut starch showed higher complexing ability with all the lipids than maize and potato reference samples. These differences in complexing ability among the starches could be due to the variation in amylose contents (Bambara groundnut starch: 31.5%, maize: 22.5% and potato: 24.6%). Fatty acids complexed better with Bambara groundnut starch than lysophosphatidylcholine, which could be due to the structural differences in comparison with the lysophosphatidylcholine molecule. The number of fatty acid in the glycerol backbone and the additional steric hindrance of the polar phosphatidic acid group in the lysophosphatidylcholine may have reduced its complexing ability. Among the fatty acids, palmitic acid complexed better than stearic and the unsaturated fatty acids, possibly due to its short chain length compared to other fatty acids. Bambara groundnut starch showed reduced peak and setback viscosities in the presence of stearic acid, linoleic acid and lysophosphatidylcholine, suggesting the formation of V-amylose complex. Bambara groundnut starch pasted with lipids displayed reduced gelling ability compared to their unmodified counterparts. XRD studies of freeze-dried paste revealed peaks at 2Ѳ = 7.4, 12.9 and 19.9o confirming the formation V-amylose complexes in Bambara groundnut starch. Modification of Bambara groundnut starch with lipids resulted in reduced digestibility. High-pressure homogenization significantly increased the complexing ability of Bambara groundnut starch with lipids. Homogenized Bambara groundnut starch-lipid complexes generally exhibited higher complex index than their unhomogenized counterparts. The higher complexing ability could be attributed to the effect of high-pressure which may have enhanced greater dispersion of lipids in the starch-water system. X-ray diffraction studies also revealed the formation of higher complexes as shown by high intensities at peaks (2Ѳ= 7.4, 12.9 and 19.9o) corresponding to V-amylose complexes. Bambara groundnut starch-lipid complexes displayed significantly higher melting temperatures (95.74-103.82oC) compared to native uncomplexed starch (77.32oC). Homogenized Bambara groundnut starch complexes were non-gelling while the unhomogenized types produced weak gels, with G′ ˃ G″ in the range of 0.1- 10 Hz. Complexation of Bambara groundnut starch with lipids using high-pressure homogenization may be employed in the production of modified starch with non-gelling properties and higher thermal stability suitable for certain industrial application, such as fat replacers in mayonnaise, frozen foods and desserts for a better mouth feel. The physicochemical and mechanical properties of biofilm prepared from Bambara groundnut starch modified with stearic acid at varying concentrations of 0, 2, 4, 6, 7 or 10% were further studied. By SEM, Bambara groundnut starch films containing stearic acid (˃ 2%) showed a progressively rough surface compared to those with 2% stearic acid and the control. The addition of 2% stearic acid to Bambara groundnut starch film reduced water vapour permeability by approximately 17%. However, mechanical properties of starch films were generally negatively affected by stearic acid. Bambara groundnut starch film may be modified with 2% stearic acid for improved water vapour permeability and thermal stability with minimal effect on tensile strength. / D

This dissertation addresses some of the gaps in the research on pediatric mental health (MH) repeat visits to the emergency department (ED). The primary objectives of this thesis are to systematically review the existing literature on youth MH return visits to the ED and to determine the incremental contribution of family factors in predicting these repeat ED visits. The first study systematically reviewed and qualitatively summarized the available literature to better understand predictor of repeat visits. A search was performed using the following databases: PsycINFO, PubMed, and CINAHL. Reporting followed the PRISMA statement checklist and methodological quality was assessed using the following eight criteria: design, generalizability, breadth of predictors, reporting of effect sizes, additional outcomes, interaction terms, confounding variables, and clear definition of outcome. A total of 178 articles were retrieved; 11 articles met inclusion criteria. Findings revealed that repeat visits to the ED for MH concerns is a complex phenomenon that can be attributed to various demographic, clinical, and MH care access and utilization factors. Common predictors associated with repeat ED MH visits included socioeconomic status, involvement with child protective services, as well as previous and current MH service use. For studies using a six-month repeat window, the most common factors were previous psychiatric hospitalization and currently receiving MH services. This systematic review concluded that in order to further elucidate which variables are most significantly associated with repeat ED visits; future research should consider the use of prospective designs and the inclusion of family factors. Investigating recency and frequency outcomes may also be of importance. The second study aimed to determine if family characteristics are significantly associated with repeat ED visits over and above the contribution of demographic, clinical or service utilization factors. A retrospective cohort study of youth aged six to18 years treated at a tertiary pediatric ED for a discharge diagnosis related to MH was conducted. Data were gathered from medical records, telephone interviews, and questionnaires. Of 266 participants, 70 (26%) had a repeat visit. Receiving MH services within six-months of the index visit, having a parent with a history of treatment for MH concerns, higher severity of symptoms and living closer to the hospital were significantly associated with repeat visits as well as earlier and more frequent repeat visits. Prior psychiatric hospitalization was associated with repeat visits and more frequent repeat visits, while presenting with suicidality was associated with more frequent repeat visits. Family functioning and perceived family burden were not associated with repeat ED visits. This thesis contributes to the growing literature on ED use in pediatric patients with mental illnesses and may be clinically useful to professionals working with repeat visitors. The identification of key factors could provide essential information to ED decision-makers and lead to the development of best practices with this population.

Abstract The aim of this cross-sectional controlled study was to determine frequent attenders' chronic diseases and their reasons for encounter in primary health care. Furthermore, the study aimed to determine the associations of social, psychological and family factors with frequent attendance in a Finnish health centre. Patients who made eight or more annual visits to physicians in the health centre during one year were defined as frequent attenders (FA). All the FAs during 1994 (N=304) and 304 randomly selected age- and sex-matched controls constituted the study population. The data were collected from annual statistics, medical records and postal questionnaires. Over one third of the study population was interviewed. International Classification of Primary Care (ICPC) was used to determine the reasons for encounter and Symptom Checklist - 36 (SCL-36) to assess the psychological distress. Toronto Alexithymia Scale -20 (TAS-20) was used as a measure of alexithymia and Whiteley Index (WI) to determine hypochondriacal beliefs. The results showed that 4.7% of the whole population aged 15 years or older in Oulainen were FAs. They accounted for 23.5% of all visits made within the respective age group. The mean age of the FAs was 49.8 years. Over two thirds of them were female. The FAs had lower basic education and occupational status than the controls. The FAs visited physicians in the health centre mostly for reasons related to the musculoskeletal, respiratory and digestive systems. There appeared to be more chronic diseases among the FAs than among the controls. The FAs had over three times more mental disorders than the controls. The interviewed FAs had significantly more psychological distress, somatization and hypochondriacal beliefs than the controls. The risk of frequent attendance was higher in the older family life cycle phases than in the younger family life cycle phases. Multivariate analyses showed chronic somatic disease and hypochondriacal beliefs to be risk factors for frequent attendance. Concurrence of somatization and hypochondriacal beliefs increased the risk to be a FA. As a conclusion, the results emphasize the need to consider the FAs' own bodily concerns expressed as hypochondriacal beliefs when managing them. Furthermore, the study implicates a need to integrate the biomedical, psychological and social dimensions in the care of FAs in primary health care.

The objective of the study was to determine the feed conversion efficiency (FCE), carcass characteristics, physico-chemical quality, fatty acid (FA) composition and shelf life of pork from pigs fed diets containing either 0% (T1), 2.5% (T2), 5% (T3) or 7.5% (T4) Moringa oleifera leaf meal (MOLM). Consumer health-related perceptions on pork and fatty acids were also investigated. Twenty four crossbred Large White x Landrace pigs of both sexes at 18 weeks of age and initially weighing 71.6 kg on average were housed individually and had ad libitum access to one of the four dietary treatments for a period of six weeks. Average daily feed intake (ADFI) and average daily gain (ADG) and feed conversion ratios (FCR) were calculated as an indication of FCE and pigs were slaughtered at an average live weight of 99.6 kg. Carcass traits such as back fat thickness (BFT), carcass temperatures and pH readings taken 45 minutes and 24 hours (pH45 and pHu) post mortem were recorded. M. longissimus thoracis et lumborum (LTL) samples were taken from each carcass for the determination of lightness (L*), redness (a*), yellowness (b*), thawing loss percentage (TL%), cooking loss percentage (CL%), Warner Bratzler Shear Force (WBSF), shelf life and FA composition. Furthermore a survey was conducted amongst 80 University of Fort Hare Students to determine their health-related perceptions on pork and fatty acids as well as their pork consumption frequency using questionnaires. The FCE of pigs fed on 0-5% MOLM (T1, T2 and T3) diets did not differ significantly, but the FCE of pigs fed 7.5% MOLM (T4) was significantly (p<0.05) reduced. No significant relationship was reported between inclusion of MOLM carcass characteristics and physico-chemical pork quality. There was however a significant improvement (p<0.05) in the shelf life of the pork from MOLM fed pigs in terms of colour and odour during 10 days of refrigerated storage (at 3±1°C). There was a significant (p<0.05) reduction in the total intramuscular fat (IMF) content and the saturated fatty acid (SFA) C18:0 (stearic acid) content and an overall non-significant (p>0.05) increase in the poly unsaturated fatty acid (PUFA) content of pork from MOLM fed pigs. The possible reason for this is that the feeding of MOLM was commenced when the pigs were at an advanced age and weight. The survey revealed that the majority of interviewed students consume fresh (39.7%) and processed (32.4%) pork two to three times a week, perceive pork to be generally healthy (70%) and the second most healthy meat type (39.5%). While the majority (55.4%) were aware of the health implications of FAs they did not know which FA classes pose more of a health risk (51.3%). In conclusion2.5% and 5% of MOLM in finisher pig feed did not negatively affect FCE, carcass characteristics or physico-chemical meat quality; significantly improved pork shelf life and reduced total IMF and SFA content of pork but 7.5% MOLM negatively affected FCE; and the majority of students perceive pork to be the second most healthy type of meat and are generally aware of the health implications of FAs.

Carbohydrates have variable digestibilities and metabolizable energy values in carnivorous fish. Simple sugars are generally more digestible than complex polysaccharides, and low levels of dietary carbohydrate may contribute more metabolizable energy than high levels. Two experiments were conducted to study the effects of dietary level and processing treatment of wheat starch on the digestibility of diets fed to sablefish (Anoplopoma fimbria), in different regions of the digestive tract. Moreover, an experiment was undertaken to determine if the dietary concentration of an indigestible external marker (chromic oxide) influenced its motility, relative to other ingredients in the ingesta, as it passed through the digestive tract. Lastly, a growth experiment was undertaken to compare the performance of sablefish fed formulated diets containing one of two levels of carbohydrate to that of fish fed a natural fish diet. The gastric evacuation of a formulated and a natural diet were also investigated. Apparent digestibility values for the nutrients in a formulated diet (containing 44.4% cooked wheat and 0.1% chromic oxide) fed to sablefish were noted to increase progressively from the anterior to the posterior regions of the intestinal tract. Within each region of the gut, the apparent digestibility values for most nutrients declined over three sample periods. Carbohydrate (nitrogen-free extract) digestibility down to the distal section of the intestine ranged from 51.0 to 82.8%. An experiment designed to assess the effect of carbohydrate treatment on the digestibility of four isonitrogenous, isocaloric diets met with partial failure. It was determined that the 1.0% chromic oxide marker flowed at a differential rate to the rest of the ingesta in the digestive tract, which violated the criteria for an effective marker. Consequently, diet digestibility was not determined in this experiment. Hepatic glycogen levels in fish receiving the dietary treatments were compared, and these values were used to estimate the relative availability (digestibility) of carbohydrate from the respective diets. According to this index, the sequence for digestibility was as follows: pregelatinized starch > cooked wheat > pregelatinized starch/cooked wheat > unprocessed wheat. Differential movement of chromic oxide relative to other ingesta was observed in sablefish fed on alternate days regardless of the dietary concentration of the indigestible marker (0.1 or 1.0%). It was surmised that the feeding protocol established the circumstances from which marker 'streaming' was observed in the results. Differential transport of Cr₂O₃ through the gut by ingested seawater was suggested as a possible mechanism for the phenomenon. Sablefish fed a natural fish diet had the highest growth rates, condition factors, liver lipid levels and the lowest feed conversion ratios and liver glycogen levels. Sablefish fed a diet containing 22.2% cooked wheat had a higher growth rate, condition factor, and a lower food conversion ratio, than those fed a diet containing 44.4% cooked wheat. Ingestion of the 44.4% cooked wheat diet resulted in the highest values for liver glycogen and hepatosomatic index. It was concluded that sablefish have a limited ability to metabolically utilize digestible carbohydrate and that most of the dietary non-protein energy should originate from high quality lipid for maximum protein sparing. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate

Formaldehyde treatment of dietary protein to reduce its degradation in the rumen has been reported to be beneficial in some instances. Four levels of formaldehyde (0.0%, 0.8%, 1.0% and 1.2% on an air dry basis) were applied to a dehydrated and hammermilled grass-clover forage. In vitro nitrogen digestibility and ammonia-nitrogen production at *the microbial stage of incubation were reduced significantly (p < 0.05) as the level of formaldehyde was increased. Nitrogen digestibility for the combined microbial and acid-pepsin stages of incubation was significantly (p < 0.05) reduced only at the 1.2% level of formaldehyde application compared to the untreated forage. Ram lambs ranging in body weights of 29kg to 36kg were then used in studies of nitrogen and carbohydrate metabolism. One percent formaldehyde was applied to the grass-clover forage. Each of the five diets (14% C.P. on D.M. basis) contained 50% grass-clover forage, 38% cassava, 11% barley and 1% sheep mineral premix on a dry matter basis. Diet one contained the untreated forage while the others contained the formaldehyde treated forage. Diets three and five were supplemented with isovaleric acid (3.0g/Kg diet) and isobutyric acid (2.3g/Kg diet). Diets four and five were supplemented with sulphur in the form of sodium sulphate. The apparent digestibility coefficients of acid-detergent fibre and cellulose were increased significantly (p < 0.05) by formaldehyde treatment of the forage. The apparent digestibility coefficient of nitrogen was significantly (p < 0.05) depressed by formaldehyde treatment of the forage except for the diet supplemented with VFAS (diet three). The apparent digestibility coefficients of dry matter and organic matter were not affected significantly (p > 0.05). Ruminal fluid levels of isovaleric and isobutyric acids were significantly (p < 0.05) higher for animals fed diet three than for animals fed diets two and four. Formaldehyde treatment of the forage resulted in significantly (p < 0.05) higher levels of valeric acid and lower levels of ammonia in ruminal fluid. Ruminal fluid levels of total volatile fatty acids, acetic, propionic and butyric acids and rumen pH were not affected significantly (p < 0.05) by formaldehyde treatment of the forage. The ratio of microbial protein-nitrogen (estimated from RNA-N) to total abomasal digesta nitrogen was significantly (p < 0.05) decreased by formaldehyde treatment of the forage except for the diet supplemented with VFAS (diet three). The concentration of non-protein-nitrogen in abomasal digesta was significantly (p < 0.05) reduced by formaldehyde treatment of the forage. Abomasal digesta pH, concentration of total nitrogen, RNA-N, microbial protein-nitrogen, acid-detergent fibre, and cellulose were not affected. The reduction in the ratio of microbial protein-nitrogen to total abomasal digesta nitrogen and non-protein-nitrogen by formaldehyde treatment of the forage suggests that the treatment reduced microbial degradation of dietary protein except perhaps for the diet supplemented with VFAS (diet three). Nitrogen balance was significantly (p < 0.05) improved by formaldehyde treatment of the forage except for the sulphur supplemented diets. Sulphur supplementation tended to offset the beneficial effects of formaldehyde protection of the forage protein. Supplementation with VFAS did not further enhance nitrogen utilization. Formaldehyde treatment of the forage significantly (p < 0.05) improved sulphur balance except for the diet supplemented with both sulphur and VFAS (diet five). Daily feed intake and urine output per unit metabolic body size and growth rate over a seventeen-day period were not significantly (p < 0.05) affected by formaldehyde treatment of the forage. The flow of total digesta, organic matter, dry matter, acid-detergent fibre, cellulose and total nitrogen through the duodenum for a 24-hour period was markedly higher for the diets containing the formaldehyde treated forage. The flow of microbial protein-nitrogen and non-protein-nitrogen however was markedly depressed by formaldehyde treatment of the forage. A sheep fitted with a duodenal re-entrant cannula was used for this study. / Land and Food Systems, Faculty of / Graduate