Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2018. / Ticks and tick-borne diseases are important limiting factors to the attainment of sustainable animal and human health, affecting livelihood of resource poor farming communities in developing countries. Rhipicephalus appendiculatus and Amblyomma variegatum (Ixodidae) are among the most troubling tick species in Africa. While ticks can be controlled by applying chemical acaricides, these chemicals are quite expensive, especially, for small-scale famers in developing countries. Hence, the quest for alternative tick control over the years have revealed that entomopathogenic fungi (EPF) and plant extracts have huge prospects as sustainable alternatives for tick control. Beauveria bassiana (Hypocreales) is a fungal entomopathogen with the ability to colonize plants endophytically and induce secondary metabolite production in plants, and it has been found to be a potential biological control agent against a wide range of arthropods. Several plant species including plant species belonging to the family Alliaceae possess anti-tick activities (repellent and toxic); therefore, integrating the two strategies by inoculating Tulbaghia violacea with B. bassiana could enhance secondary metabolite contents in extracts obtained from the plant and increase medicinal materials. The primary purpose of the present study was to evaluate the effect of indigenous endophytic entomopathogens inoculation of T. violacea on the plant growth, tissue nutrient contents and secondary metabolites, and anti-tick activities of extracts of T. violacea. The specific objectives were: (i) to carry out a study on the effects of inoculating T. violacea with fungal strains of B. bassiana and Clonostachys rosea on plant growth and tissue nutrient contents in extracts of T. violacea with the view of selecting one of the two fungi for further investigation (ii) to compare secondary metabolite profiles of extracts obtained from plants exposed to fungus (EPF) inoculum and control treatment during cultivation, and (iii) to determine whether exposure of T. violacea to an endophytic fungus (B. bassiana) during cultivation affects the repellent and acaricidal activities of extracts of T. violacea on A. variegatum and R. appendiculatus. The study had two experiments, presented in chapters two and three. In the first experiment, eight weeks old potted seedlings of T. violacea were inoculated separately with B. bassiana (strain SM3) and C. rosea (strain SM8) conidia suspended at concentrations of 1 x 106 conidia mL-1. Plant growth parameters, such as number of leaves, plant height (aerial part), fresh weights of aerial parts, and tissue nutrient contents were assessed. Results indicated that B. bassiana induced higher growth of plants than C. rosea. Inoculation with B. bassiana did not significantly (P ˃ 0.05) influence most of the growth parameters, number of leaves, fresht weight of roots and of fresh weight aerial parts (leaves) of T. violacea assessed in the current study. However, mean plant heights and root lengths were significantly (P < 0.05) higher in favour of B. bassiana treated plants compared to those in C. rosea. Fe contents in the roots (1416.3 ± 305.10 mg/kg) were found to be positively influenced (P < 0.05) by the fungal inoculation. There was a significant difference in roots (P < 0.05) on the uptake of Mn in C. rosea treated plants (243 ± 19 mg/kg) compared to the control group (169 ± 16.37 mg/kg) and B. bassiana treated roots (161.3 ± 14.44 mg/kg). Macro nutrients up take did not differ significantly among treatments on both leaves and roots (P > 0.05).

Este estudo discute a AIDS enquanto um fenômeno simbólico para indivíduos a partir da experiência clínica e do referencial teórico da psicologia analítica.A técnica utilizada foi a análise de registros de sonhos. Durante 22 meses foram registrados 125 sonhos de 9 de pessoas infectadas pelo HIV, e os sintomas relacionados à AIDS. Destes foram selecionadas três séries oníricas totalizando 74 sonhos, segundo os critérios: idade, sexo, orientação sexual, escolaridade, nível sócio-econômico, período de infecção, período de coleta de dados, local de atendimento e número e qualidade dos sonhos registrados. A análise foi realizada primeiro, a partir das associações e dos dados coletados durante as sessões, procurando verificar as relações entre os sonhos e o momento de vida do indivíduo. A seguir, identificou-se a constelação arquetípica mais presente em cada série, amplificando-a a nível arquetípico e relacionando-a com a situação psicológica do sujeito. Procurou-se também averiguar o movimento de compensação e/ou adaptação do inconsciente à experiência de vida marcada pela AIDS. E por último, analisou-se as três séries em conjunto procurando destacar os pontos relevantes para a compreensão do fenômeno da AIDS como um todo. A análise dos dados indica que a AIDS, enquanto fenômeno simbólico, pode ser inserida em um movimento de reestruturação amplo da personalidade. A compensação parece dar-se dentro deste processo e não em relação ao evento da AIDS isoladamente. Porém, foram registradas constelações do Self durante os eventos somáticos mais graves, o que pode indicar um esforço compensatório frente a uma situação de ameaça à vida. Os sintomas menos graves foram acompanhados pela emersão de conteúdos da sombra com os quais parecem ter uma relação simbólica. As várias referências ao mito de Dioniso ao longo das séries pode indicar, que a nível coletivo, a epidemia da AIDS faz parte de um movimento compensatório à cultura judaico-cristã-apolínea, que visa redimensionar a consciência, através da integração dos elementos instintivos da psique. / This study focuses on AIDS while a symbolic phenomenon in individuals, based on clinical experience supported by the analytical psychology theory. The technique used in this work was dream analysis. In a period of 22 months it was registered 125 dreams of 9 people infected with HIV, as well as the symptoms related to AIDS. It was selected three series of dreams totaling 74 dreams according to: age, sex, sex orientation, scholarship, social-economic level, period of infection and data registration, counseling place and amount of registered dreams. First, the analysis was made, from the associations and therapy sessions' data, in order to verify the relations between dreams and the individual situation. Next it was identified the archetypal constellation present in each series. This archetypal constellation was amplified at archetypal level and related to the psychological situation of the individual. It was also verified the compensation and the adaptation movement in relation to AIDS. Finally, the three series were analyzed all together and the significant aspects to the comprehension of AIDS phenomena were discussed. The data analysis suggests that AIDS, while a symbolic phenomenon, can be understood as part of a great movement of personality change. The compensation movement seems to take place in this process and not in relation to AIDS. However, Self constellations were registered during the most serious somatic events, what can denote a compensation in face of a threatening life situation. Less serious somatic events were followed by the emergence of shadow contents, with which they seem to have a symbolic relation. Many references to Dioniso myth can indicate at a collective level, a compensatory movement against the Judaic-Christian-Apolinean culture that aims the consciousness transformation by integrating the instinctive elements of the psyche.

Orientador: Gervásio Henrique Bechara / Banca: Romário Cerqueira Leite / Banca: Rosângela Zacarias Machado / Resumo: No presente estudo avaliou-se o desenvolvimento de resistência a ninfas do ixodídeo Amblyomma cajennense, induzida por infestações controladas, e a possível existência de reatividade cruzada com Amblyomma hebraeum. Para tal, caprinos sem contato prévio com carrapatos, com seis meses de idade, machos ou fêmeas, foram infestados três vezes sucessivamente com ninfas de A. cajennense. Ademais, outro grupo de caprinos foi infestado nas mesmas condições com ninfas de A. hebraeum e colhidos soros para pesquisa de possível reatividade cruzada com A. cajennense. Observou-se que caprinos desenvolveram resistência apenas parcial a ninfas de A. cajennense, como demonstrado pela alteração significativa dos seguintes parâmetros biológicos das ninfas, em relação à primoinfestação: redução de 41,7% e 37,1% no peso de ingurgitamento, respectivamente na 2ª e 3ª infestações; aumento de 20% no período de ecdise e redução de 25,7% na taxa de ecdise, respectivamente nas 3ª e 2ª infestações. Não houve alteração no período de ingurgitamento nem na porcentagem de recuperação de ninfas com as infestações sucessivas. A reação cutânea induzida pelas ninfas de A. cajennense durante as infestações em caprinos caracterizou-se por infiltrado de células inflamatórias, predominantemente neutrófilos e basófilos, estas últimas envolvidas na imunidade a carrapatos por meio de hipersensibilidade basofílica cutânea. Células apresentadoras de antígeno, nomeadamente macrófagos, linfócitos B e células dendríticas foram detectadas por imunoistoquímica em linfonodos drenantes de locais de fixação dos carrapatos, em maior número nos linfonodos dos animais infestados... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study evaluated the acquision of resistance against Amblyomma cajennense nymphs in naïve goats, induced by repeated and controlled infestations, and a possible cross-reactivity with A. hebraeum. Ten naive goats, of both sexes, aged six months were used throughout the experiment. Animals were infested artificially thrice, 30 days intervals between infestations. In addition, goats were infested at same conditions with the tick A. hebraeum as well. Sera from these animals were collected looking for possible cross-reactivity between antigens from these ixodids. It was observed that goats developed partially resistance to A. cajennense nymphs from the 1st infestation on as shown by changes in some biological parameters, as follows: increase of 41.7% and 37.1% in engorgement weight, respectively at the 2nd and 3rd infestations, decrease in 25.7% in nymph’s ecdise rate and increase of 20% in ecdise period, respectively at the 3rd and 2nd infestations. It was not observed alterations in engorgement period and percentage of yielded nymphs. Biopsies of tick bite lesions induced by A. cajennense nymphs during infestations in goats were characterized by inflammatory reaction with cellular influx by neutrophils and basophils predominantly, being the last one involved in the well-known cutaneous basophilia. Antigen presenting cells like macrophages, B-lymphocytes and dendritic cells were detected by immunohistochemical analysis of lymph nodes draining tick infested areas. It should be stressed that these cells were found in higher numbers at lymph nodes from infested goats than from the naïve ones. Western blotting analysis of nymphal A. cajennense extracts revealed shared polypeptides (160, 90 and 16kDa) when used sera from goats infested with A. cajennense either A. hebraeum, indicating cross reactivity between these two tick species. / Mestre

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2017-01-05T09:37:46Z No. of bitstreams: 2 Dissertação - Priscila Bianca Rodrigues da Rocha - 2016.pdf: 3342071 bytes, checksum: 4810677b5ff246d6d0dd384d773187fd (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-01-05T10:33:16Z (GMT) No. of bitstreams: 2 Dissertação - Priscila Bianca Rodrigues da Rocha - 2016.pdf: 3342071 bytes, checksum: 4810677b5ff246d6d0dd384d773187fd (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-01-05T10:33:16Z (GMT). No. of bitstreams: 2 Dissertação - Priscila Bianca Rodrigues da Rocha - 2016.pdf: 3342071 bytes, checksum: 4810677b5ff246d6d0dd384d773187fd (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-03-31 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The extract of Centella asiatica L. Urban (CA) plant has been used both for cosmetic purposes and for the treatment of cutaneous diseases, due to its cicatrizing and antiproliferative activities. The main active component of this plant, asiaticoside (AS), has an important effect on scleroderma (ES), a disease that affects the skin causing its thickening and hardening. These characteristics make difficult the localized topical treatment of ES. Thus, nanostructured lipid carriers (NLC) containing the CA extract were developed and characterized for the topical application of AS. The NLC were produced with a 1: 3 mixture of solid and liquid lipids (stearic acid and oleic acid, respectively), 0.25% sodium taurodeoxycholate and 1% soy lecithin by the microemulsion technique. For formulations with higher amounts of lipid, concentrations of 2 to 4% of the lipid mixture were evaluated. After the development of high lipid particles, different concentrations of CA dry extract (0.926, 1.274 and 1.853%) and glycolic extract (1.282, 2.418 and 3.336%) were added to the formulations. All NLC were characterized for mean diameter, polydispersity index (PdI), zeta potential, encapsulation efficiency (EE%) and drug loading (DL%). In vitro release and permeation studies of the unencapsulated extract (aqueous dispersions and commercial cream) and encapsulated were evaluated using Franz cells. The NLC obtained had a mean size of 130 nm and a uniform size distribution, with a PdI of 0.2, and an encapsulation efficiency of more than 90% for NLC containing dry extract and 40% for NLC developed with glycolic extract. The AS release profile from the developed formulations showed a controlled release, no more than 45% in 48 hours of study. Encapsulation of the dry extract in NLC resulted in an increase in AS retention in the stratum corneum 2-fold compared to the unencapsulated extract in aqueous dispersion, but was similar to the retained amount of AS when the commercial formulation was applied topically. NLC developed with glycolic extract were able to increase the permeation of AS to the deeper layers of the skin, when compared to the carriers containing the CA dry extract and the commercial cream. The results suggest that these systems significantly increase the permeation of AS and, therefore, may present potential benefits for the treatment of cutaneous diseases such as ES. / O extrato da planta Centella asiatica L. Urban (CA) tem sido utilizado tanto para fins cosméticos quanto para tratamento de doenças cutâneas, devido as suas atividades cicatrizantes e antiproliferativas. O principal componente ativo desta planta, o asiaticosídeo (AS), tem um importante efeito na esclerodermia (ES), doença que acomete a pele causando o seu espessamento e endurecimento. Estas manifestações dificultam o tratamento tópico localizado da ES. Assim, carreadores lipídicos nanoestruturados (CLN) contendo o extrato da planta CA foram desenvolvidos e caracterizados visando a aplicação tópica do AS. Os CLN foram produzidos com uma mistura de 1:3 de lipídeos sólido e líquido (ácido esteárico e ácido oleico, respectivamente), 0,25% de taurodeoxicolato de sódio e 1% de lecitina de soja pela técnica da microemulsão. Para produção de formulações com maior quantidade de lipídeo, concentrações de 2 a 4% da mistura de lipídeos foram avaliadas. Após o desenvolvimento das partículas com alto teor lipídico, diferentes concentrações do extrato seco de CA (0,926, 1,274 e 1,853%) e do extrato glicólico (1,282, 2,418 e 3,336%) foram adicionadas às formulações. Todos os CLN foram caracterizados quanto ao diâmetro médio, índice de polidispersão (PdI), potencial zeta, eficiência de encapsulação (EE%) e carga de fármaco (CF%). Estudos de liberação e permeação in vitro do extrato não encapsulado (dispersões aquosas e creme comercial) e encapsulado foram avaliados utilizando células de “Franz”. Os CLN obtidos apresentaram tamanho médio de 130 nm e distribuição de tamanho uniforme, com PdI de 0,2, além valores de eficiência de encapsulação superiores a 90% para os CLN contendo extrato seco e 40% para os CLN desenvolvidos com extrato glicólico. O perfil de liberação do AS a partir das formulações desenvolvidas mostrou uma liberação controlada, não mais que 45% em 48 horas de estudo. A encapsulação do extrato seco nos CLN resultou em aumento na retenção de AS no estrato córneo de 2 vezes, comparado ao extrato não encapsulado em dispersão aquosa, mas foi semelhante a quantidade retida de AS quando a formulação comercial foi aplicada topicamente. Os CLN desenvolvidos com extrato glicólico foram capazes de aumentar a permeação do AS para as camadas mais profundas da pele, em relação aos carreadores contendo o extrato seco da CA e o creme comercial. Os resultados sugerem que estes sistemas aumentam significativamente a permeação do AS e, por isso, podem apresentar potenciais benefícios para o tratamento de patologias cutâneas como a ES.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2014-09-03T21:30:23Z No. of bitstreams: 2 DISSET Correção FINAL 03-07-14 FOLHA PDF.pdf: 1467526 bytes, checksum: 196b53fbd9a59de359b14f8fd82c2ee5 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-09-03T21:30:23Z (GMT). No. of bitstreams: 2 DISSET Correção FINAL 03-07-14 FOLHA PDF.pdf: 1467526 bytes, checksum: 196b53fbd9a59de359b14f8fd82c2ee5 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-01-29 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Paclitaxel (PTX) is a natural product extracted from the bark of the Pacific Yew and has numerous antitumor actions, including skin cancers. The topical treatment of skin and pre-cancerous lesions cancer is desired, since the systemic treatment has many side effects However, PTX to be incorporated into formulations suitable for it to penetrate the stratum corneum and skin tumors reached. Lipid nanoparticles have potential to increase drug retention in the stratum corneum, thus providing controlled release and great percutaneous absorption. Within this context, the aim of this study was to develop and characterize solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) containing the antineoplastic PTX and evaluate its permeation into the pig ear skin in vertical diffusion cells type "Franz". Quantification of PTX paclitaxel was performed by high performance liquid chromatography. The NLS and CLNs were obtained by the method of dilution of the microemulsion containingcetylpyridinium chloride, glyceryl behenate, triglycerides of caprylic / capric acid, polysorbate 80 and sorbitan trioleate 85. The particles were characterized by medium size, PdI, zeta potential, encapsulation efficiency, drug loading and recovery. Stability studies were carried out for a period of 30 days with storage at 4 °C (± 2 °C). Theskin permeation studies of the PTX nanoparticles were conducted in “Franz” type diffusion cells in pig ear skin. The NLS obtained showed average size of 314.1 ± 10.9 to 335.9 ± 0.9nm. The CLN obtained with more oil in the lipid matrix (CLN100)showed average size 270.6 ± 13.5 nm. The encapsulation efficiency of the systemsobtained was above 90% when 3.75% was added PTX formulations. The stability studies revealed a trend in increasing the size of the particles PdI along the storage period, but these differences are not statistically significant. The CLN100 increased about 3 times the amount of drug in the stratum corneum (SC) as compared to the administration of unencapsulated drug and also increased by 1.5 times the amount of PTX in the SC in relation to the topical application of other lipid particles. Thus, the lipid particles appear to be promising systems for topical application of PTX. / O paclitaxel (PTX) é um produto natural extraído da casca do Teixo do Pacífico e possui númeras ações antitumorais, inclusive em neoplasias cutâneas. O tratamento tópico do câncer de pele e de lesões pré-cancerígenas é almejado, visto que o tratamento sistêmico possui diversos efeitos colaterais. Entretanto, o PTX precisa ser incorporado em formulações adequadas para que o mesmo penetre no estrato córneo e atinja os tumores cutâneos. As nanopartículas lipídicas apresentampotencial para aumentar a retenção de fármacos no estrato córneo, proporcionandouma liberação controlada e um aumento na absorção percutânea. Dentro destecontexto, o objetivo deste trabalho foi desenvolver e caracterizar nanopartículaslipídicas sólidas (NLS) e carreadores lipídicos nanoestruturados (CLN) contendo o antineoplásico PTX e avaliar sua permeação cutânea em pele de orelha de suíno em células de difusão vertical tipo “Franz”. A quantificação do paclitaxel PTX foi realizada por cromatografia líquida de alta eficiência. As NLS e CLN foram obtidas pelo método de diluição da microemulsão contendo cloreto de cetilpiridínio, behenato de glicerila, triglicerídeos do ácido cáprico/ caprílico, polissorbato 80 e trioleato de sorbitano 85. As partículas foram caracterizadas quanto ao tamanho médio, PdI, potencial zeta, eficiência de encapsulação, carga de fármaco e recuperação. Os estudos de estabilidade foram realizados por um período de 30 dias com armazenamento a 4°C (± 2°C). Os estudos de permeação cutânea do PTX nas nanopartículas foram realizados em células de difusão tipo “Franz” em pele de orelha de suíno. As NLS obtidas apresentaram tamanho médio entre 314,1 ± 10,9 a 335,9 ± 0,9nm. Os CLN obtidos com mais óleo na matriz lipídica (CLN100), apresentaram tamanho médio 270,6 ± 13,5nm. A eficiência de encapsulação dos sistemas obtidos foi superior a 90% quando 3,75% de PTX foi adicionado as formulações. Nos estudos de estabilidade observou-se uma tendência no aumento do tamanho e PdI das partículas ao longo do período de armazenamento, porém estas diferenças não são estatisticamente significativas. Os CLN100 aumentaram aproximadamente 3 vezes a quantidade de fármaco no estrato córneo (EC) quando comparados com a administração do fármaco não encapsulado e, ainda ,aumentaram 1,5 vezes a quantidade de PTX no EC em relação à aplicação tópica das demais partículas lipídicas. Desta forma, as partículas lipídicas parecem ser sistemas promissores para aplicação tópica do PTX.

Thesis (M.Sc. (Plant protection)) --University of Limpopo, 2013. / Studies were initiated to investigate (1) the aggressiveness of the citrus nematode (Tylenchulus semipenetrans Cobb) isolates from two provinces in South Africa (2 experiements ) and (2) the biotype of T. semipenetrans in South Africa. In the aggressive study, isolates from Limpopo and Mpumalanga Provinces were used on Carrizo citrange (Citrus sinensis × Poncirus trifoliata) and rough lemon (Citrus jambhiri) seedling rootstocks under greenhouse conditions (18 experiements). Each seedling was inoculated with 0, 10 000, 20 000, 30 000 and 40 000 J2s of T. semipenetrans isolates, which were arranged in a randomised complete block design, with six replications. At 120 days, the reproductive factor of T. semipenetrans isolate from Mpumalanga Province was significantly higher than that from Limpopo Province. Similarly, due to its higher relative impact on the reproductive factor values, the Mpumalanga isolate reduced plant growth variables more than the Limpopo isolate. Consequently, the Mpumalanga isolate was viewed as being more aggressive than the Limpopo isolate, suggesting that there might be genetic variability and/or adaptation in populations from the two locations. A national study, comprising T. semipenetrans isolates from 18 citrus-producing district municipalities in South Africa was then initiated under greenhouse conditions using isolates from each district – for a total of 18 separate experiments. Three differential hosts, viz. rough lemon, P. trifoliata and olive (Olea europaea), served as treatments, arranged in a randomised complete block design, with 15 replications. Initially, an orchard was randomly selected in each of the six citrus-producing provinces, viz. Eastern Cape, KwaZulu Natal, Limpopo, Mpumalanga, North West and Western Cape. Three-month old differential host seedlings were inoculated with approximately 10 000 J2s of T. semipenetrans and allowed to establish and grow under greenhouse conditions. At 120 days, penetration indices and standardised reproductive potentials/g roots demonstrated that T. semipenetrans failed to reproduce and develop on olive, but reproduced and developed on the other two hosts. Using T. semipenetrans biotype classification system, findings suggested that the biotype in citrus-producing district municipalities was Poncirus biotype. This biotype reproduces on P. trifoliata and hybrid rootstocks, which therefore, suggested that trifoliate orange and its hybrid rootstocks were not suitable for use in managing population nematode densities of T. semipenetrans in South Africa. In conclusion, results of this study demonstrated that the South African T. semipenetrans biotype was Poncirus, which suggested different management decisions and strategies for the citrus industry with regard to the management of this nematode. / By National Research Foundation, National Department of Agriculture, Forestry and Fisheries and the Land Bank Chair of Agriculture − University of Limpopo,

Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines the distribution, biology and ecology of the Anguina-type nematodes and the bacterium Rathayibacter toxicus which are associated with flood plain staggers, a disease similar to annual ryegrass toxicity. Possible pasture and livestock management options to control the disease are discussed, as is biological control using the fungus Dilophospora alopecuri. / Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Plant and Pest Science, 2003?

This paper presents two applications of empirical microeconomics based on choice theoretic optimization principles. The first topic explores the determinants of subsistence time allocation in a utility theoretic model of household production. The second topic examines firm pricing behavior in a deregulated, but concentrated industry setting. The first part of this applied microeconomic analysis estimates the subsistence time versus wage labor time allocations of Alaska's North Slope inhabitants using ordered probit based on a household production model. The explanatory variables measure labor supply, demographic, and cultural influences. The major findings are as follows. First parameter estimates differ statistically and substantially between Inupiat versus non-Inupiat residents, implying that optimal natural resource management decisions may vary with the ethnicity of the resource owners. Second, marital status, age, gender, and participation in generalized gift giving and receiving are important determinants of subsistence time allocations. Third, time spent in wage labor appears to be exogenous to the subsistence time allocation decision, indicating that the time allocation process is recursive. Fourth, we find an inverse relationship between wage labor time and subsistence participation. This means that reductions in wage employment opportunities lead to increased subsistence activity. For the North Slope, this implies that Prudhoe oil depletion will result in an increase in the use of subsistence natural resources. The second part of this study turns from the individual behavior to firm behavior. During the 1980's, researchers have noted a trend towards increased concentration in the general freight, less-than-truckload (LTL) portion of the U.S. motor carrier industry. The purpose of this study is to employ new empirical industrial organization (NEIO) techniques to determine whether the more concentrated post-1980, LTL motor carrier industry is exerting anti-competitive monopoly pricing behavior. The NEIO approach is used to formulate the relationship between market price and marginal cost in what is referred to as the representative firm's 'supply relation.' The firm's supply relation is estimated jointly with the cost function and the factor share equations under the assumption that cross equation disturbance terms are correlated (SUR). An instrumental variables procedure is used to test and control for correlation between output (on the right hand side) and the disturbance terms in the cost and supply equations. The results indicate that the trend toward increased industry concentration does not imply anti-competitive performance in the sense of rising price-cost margins. / Graduation date: 1994

West Nile Virus (WNV), a vector-borne disease continues to be a serious threat to public health in the United States, particularly in the Southwest region. While all the states in the U.S. experienced a decreasing trend of WNV disease in 2010, the state of Arizona experienced a sharp increase from 20 in 2009 to 166 cases the following year. This dissertation endeavored to develop forecasting models to predict future cases of disease and identify counties with increased propensity for WNV. Furthermore, this study aimed to identify environmental and economic factors that contributed to the increase in WNV cases in Maricopa County, Arizona. A spatiotemporal stochastic regression model was developed using Bayesian principles and was successful in calculating the annual mean cases of disease from 2003 to 2011 for all counties. The model was also able to predict future cases of disease by fitting historical data. The model-based inference identified counties in the southern region of Arizona as having an elevated propensity for disease compared to counties in the northern region. A Seasonal Autoregressive Integrated Moving Average (SARIMA) model was developed and effectively forecasted monthly cases of human WNV in Maricopa County, Arizona. By fitting the SARIMA model to monthly historical disease data from 2005 to 2011, the temporal model presented a decreasing trend of monthly incidence of disease for 2012. The impact of home foreclosures, climate variability, and population growth on the resurgence of human WNV disease cases in Maricopa County during the 2010 epidemic was investigated. These factors were found to have contributed to the resurgence of the disease by creating the optimal environmental conditions that allowed the amplification of mosquito populations, thus increasing the risk of disease transmission to humans. As spatiotemporal disease data become readily available, forecasting models can be an important and viable risk assessment tool for public health practitioners. Forecasting models allow the mobilization and distribution of limited resources to areas with elevated propensity for disease, and the timely deployment of intervention programs to reduce the overall risk of disease. / Graduation date: 2013

<p>The study looked particularly at the operations of national carriers and governments&lsquo / efforts to sustain the airlines&lsquo / operations. Evidence has shown that many countries struggle to maintain operations of their flag carriers, but few countries are willing to completely leave the airlines in the hands of the private sector because of national pride. On the other hand, many of those airlines that get into private hands fail and end up being closed down or go back into state hands. These airlines are also perceived to be development tools, in particular for tourism development which is a predominant economic activity in many developing countries. For this reason, many states do not favour privatisation, even though the perception is that the airline industry is better handled by private businesses. The main conclusion of the study for Botswana is therefore that neither full state ownership nor full privatisation is the solution to addressing the problem of ailing flag carriers. There is no single solution, but a combination of several. A broader global view of national airline operations clearly shows that approaches adopted by many successful national airlines, in both developed and developing countries, is some form of partial privatisation.</p>