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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

An Exploratory Model of Medication Refill Adherence Behavior

Payne, Gayle Holmes 15 October 2009 (has links)
AN EXPLORATORY MODEL OF MEDICATION REFILL ADHERENCE BEHAVIOR by Gayle Holmes Payne Coronary heart disease (CHD) is the leading cause of death in the United States with over 15.8 million Americans suffering from the chronic disease (U.S. Department of Health and Human Services, 2007). Adherence to medication regimens has been identified as a key mediator between medical practice and patient outcomes (Kravitz & Melnikow, 2004). In this study, participants (N = 355) with CHD completed a questionnaire measuring their background characteristics, cognitive status, health literacy skills, self-efficacy levels, their perceived concerns and necessity beliefs about medication use, and enablers and barriers to their medication-taking behavior. Information regarding each participant’s number of medications and presence of disease was obtained from medical charts. Data regarding the dependent variable, cardiovascular medication refill adherence, were collected from pharmacy records. The data were used to see how the various variables work together in a model that explains cardiovascular medication refill adherence behavior. The study aimed to contribute to the body of adherence research by jointly examining all variables found to have an association with medication adherence through a path analysis to explain the determinants of medication refill adherence behavior. Analyses indicated that the hypothesized model did not fit the data. Additional analysis was conducted using a condensed revised model (age, self-efficacy, perceived concerns and necessity) and a self-reported measure of medication adherence (Adherence to Refills and Medication Scale) as the dependent variable. The revised model fit the data, X2(5, N = 355) = 6.71, p = .24. The revised model did not explain a statistically significant amount of the variance in medication adherence, suggesting that there may be other additional factors that may mediate the relationship between independent variables and medication refill adherence. Additional research is needed to reveal all the determinants of medication refill adherence behavior and to identify the most effective measure of adherence behavior. Given the number of people who suffer from CHD, and the often low rates of medication adherence, research that continues to explore and improve medication refill adherence will have a significant impact on morbidity and mortality rates.
122

Effective HIV and AIDS management : a South African construction sector model.

Harinarain, Nishani. January 2013 (has links)
Abstract available on PDF file. / Ph.D.--University of KwaZulu-Natal, Durban, 2013.
123

Prescribing patterns of antiretroviral drugs in the private health care sector in South Africa : a drug utilisation review / Daniël Jacobus Scholtz

Scholtz, Daniël Jacobus January 2005 (has links)
HIV/AIDS is already the leading cause of death worldwide (Unicef et al., 2004:10) with more than 5 million people out of a total of 46 million South Africans that were HIV positive in 2004, giving a total population prevalence rate of 11 per cent (Dorrington et al., 2004:1). Many people infected do not have access to even the basic drugs needed to treat HIV-related infections and other conditions (Wikipedia, 2004:3). The relative high price of many of the antiretroviral (ARV) drugs and diagnostics on the other hand are one of the main barriers to their availability in developing countries (Unicef et al., 2004:77). ARV drugs registered in South Africa include the Nucleoside/Nucleotide Reverse Transcriptase Inhibitors (NRTIs), Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) and Protease Inhibitors (PIs) (MCC, 2004:1). The objective of this study was to review, analyse and interpret the prescribing patterns of antiviral drugs, with special reference to antiretroviral drugs, in the private health care sector in South Africa by using a medicine claims database. A quantitative, retrospective drug utilisation review was performed. The data ranging from 1 January 2001 to 31 December 2001, 1 January 2002 to 31 December 2002, and 1 January 2004 to 31 December 2004 were used, dividing each year into three four-month periods, namely January to April, May to August, and September to December. It was found that 0.38 per cent (n=1 475 380) for 2001, 0.72 per cent (n=2 076 236) for 2002, and 1.68 per cent (n=2 595 254) for 2004 of all studied prescriptions for the research periods 2001, 2002, and 2004 respectively, contained ARV drugs. ARV drugs constituted 0.33 per cent (n=2 951 326) for 2001, 0.87 per cent (n=4 042 145) for 2002, and 1.92 per cent (n=5 305 882) for 2004 of the total number of medicine items prescribed for the study years 2001, 2002 and 2004 respectively. The total cost of ARV drugs amounted to R4 990 784.29, thus constituting 1.31 per cent of the total cost (R379 708 489) of all medicine items on the database for 2001, increased to R18 235 075.75, thus constituting 3.03 per cent of the total cost (R601 350 325) of all medicine items on the database for 2002, and increased to R34 714 483.64, thus constituting 5.25 per cent of the total cost (R661 223 146) of all medicine items on the database for 2004. It was found that 35.31 per cent (n=5 599) for 2001, 52.68 per cent (n=15 004) for 2002, and 74.27 per cent (n=43 482) for 2004 of all studied antiviral prescriptions for the research periods 2001, 2002, and 2004 respectively, contained ARV drugs. ARV drugs constituted 46.25 per cent (n=21 183) for 2001, 70.20 per cent (n=50 246) for 2002, and 85.87 per cent (n=118 718) for 2004 of the total number of antiviral medicine items prescribed for the study years 2001, 2002 and 2004 respectively. The total cost of ARV medicine items, represented 67.33 per cent (n=R4 990 784.29) during 2001, 84.72 per cent (n=R18 235 075.75) during 2002, and 91.20 per cent (n=R34 714 483.64) during 2004 of the total cost of all antiviral medicine items claimed through the database (n=R7412577.73 for 2001, n=R21523365.56 for 2002, and n=R38 064 347.38 for 2004). The average cost per ARV medicine items for 2004 increased from R317.93i190.80 for the period January to April to R369.2W219.50 for the period May to August, and decreased to R324.79±212.48 for the period September to December and resulted in a cost saving of R41 044.35 for the period May to August versus September to December for the ARV medicine items. The implementation of the pricing regulations could thus be a possible reason for this cost saving, due to fact that the single exit price only came into effect from May 2004. The weighted average number of ARV medicine items per prescription was 1.75*0.31 for 2001, increased to 2.35±0.03 to 2002 and remained stable on 2.35±0.02 for 2004. It was found that majority of prescriptions contained more combination ARV medicine items than single ARV medicine items, ranging from 6 834 (69.76 per cent; n=9 796) prescriptions containing combination ARV medicine items in 2001 and 32 941 (93.39 per cent; n=35 271) prescriptions containing combination ARV medicine items in 2002 to 98 805 (96.93 per cent; n=101 938) prescriptions containing combination ARV medicine items in 2004. Lastly, it was perceived that didanosine was the active ingredient with the largest prevalence for all three four-month periods of 2001 and also for the periods January to April and May to August of 2002, whilst efavirenz represented the active ingredient with the largest prevalence for the period September to December of 2002, and also for all three four-month periods of 2004. Didanosine represented the active ingredient with the highest total cost for the period January to April of 2001, whilst the combination of lamivudine/zidovudine represented the active ingredient with the highest total cost for the periods May to August and September to December of 2001, and also for all three-four month periods of 2002 and 2004. Nelfinavir has the highest average cost for period January to April of 2001, ritonavir for period May to August of 2001, and saquinavir mesylate for period September to December of 2001. Nelfinavir has the highest average cost for all three-four month periods of 2002, while didanosine has the highest average cost for all three four-month periods of 2004. / Thesis (M.Pharm. (Pharmacy Practice))--North-West University, Potchefstroom Campus, 2006
124

Designing guideline-based workflow-integrated electronic health records

Barretto, Sistine January 2005 (has links)
The recent trend in health care has been on the development and implementation of clinical guidelines to support and comply with evidence-based care. Evidence-based care is established with a view to improve the overall quality of care for patients, reduce costs, and address medico-legal issues. One of the main questions addressed by this thesis is how to support guideline-based care. It is recognised that this is better achieved by taking into consideration the provider workflow. However, workflow support remains a challenging (and hence rarely seen) accomplishment in practice, particularly in the context of chronic disease management (CDM). Our view is that guidelines can be knowledge-engineered into four main artefacts: electronic health record (EHR) content, computer-interpretable guideline (CiG), workflow and hypermedia. The next question is then how to coordinate and make use of these artefacts in a health information system (HIS). We leverage the EHR since we view this as the core component to any HIS. / PhD Doctorate
125

Understanding the impacts of Devil Facial Tumour Disease in wild Tasmanian devil (Sarcophilus harrisii) populations to inform management decisions

Shelly Lachish Unknown Date (has links)
Infectious diseases are increasingly being recognised as significant threatening processes in conservation biology. Developing strategies to effectively manage infectious diseases in wildlife is, therefore, of the utmost importance to the maintenance of global biodiversity. The effective management of infectious diseases relies on understanding the ecology of the host, the epidemiological characteristics of the pathogen and the impacts of the pathogen on the host population. However, for most wildlife-disease systems this information remains poorly understood. This is particularly true for endangered species threatened by novel infectious agents as opportunities to observe and assess disease impacts and host-pathogen dynamics in the wild are limited. The Tasmanian devil (Sarcophilus harrisii), the world’s largest carnivorous marsupial, is threatened with extinction as a result of an epidemic of an emerging disease, a fatal infectious cancer known as Devil Facial Tumour Disease (DFTD). In this thesis I capitalised on a unique dataset from a population of Tasmanian devils where disease arrived part-way through an intensive longitudinal study, and utilised existing genetic samples collected prior to DFTD outbreak, to determine the impact of DFTD on the demography, population dynamics, genetic diversity and population genetic structure of wild Tasmanian devils. I then used this knowledge of the impacts of DFTD impacts in an unmanaged population to evaluate the effectiveness of a disease management trial involving the selective culling of infected individuals. I employed mark-recapture models to investigate the impact of DFTD on age-specific and sex-specific apparent survival rates, to examine the pattern of variation in infection rates (force of infection), and to investigate the impact of DFTD on population growth rate. I investigated demography, life-history traits and morphometric parameters of infected and uninfected individuals to determine the impacts of DFTD on age-structure and sex-structure, female fecundity and individual growth rates. I used this information to assess the population’s ability to respond to low population densities and to compensate for the detrimental impacts of DFTD. To determine the genetic consequences of disease-induced population decline I used microsatellite DNA to compare genetic diversity, population genetic structure and dispersal patterns in three Tasmanian devil populations prior to and following DFTD outbreaks. Capture-mark-recapture analyses revealed that the arrival of DFTD triggered an immediate decline in apparent survival rates of devils, the rate of which was predicted well by the increase in disease prevalence in the population over time. Transition rates of healthy individuals to the diseased class (the force of infection) increased in relation to disease prevalence, while the arrival of DFTD coincided with a marked and ongoing decline in the population growth rate. There was a significant change to the age structure following the arrival of DFTD. This shift to a younger population was caused by the loss of older individuals as a direct consequence of DFTD-driven declines in adult survival rates. Evidence of reproductive compensation in response to these disease impacts was observed via a reduction in the age of sexual maturity of females over time. However, widespread precocial breeding in devils was precluded by physiological and ecological constraints that limited the ability of one year olds to breed. Using temporally-replicated spatial genetic data, I found evidence of increased inbreeding following DFTD arrival and greater population genetic differentiation in post-disease populations. These changes appeared to be driven by a combination of selection and altered dispersal patterns of females in DFTD-affected populations. Comparison of demographic and epidemiological parameters indicative of disease progression and impact between the managed and unmanaged populations revealed that selective culling of infected individuals neither slowed the rate of disease progression nor reduced the population level impacts of this debilitating disease; with culling mortality simply compensating for disease mortality. This thesis provides one of the few direct empirical evaluations of the impact of an emerging wildlife disease epidemic on a wild population. This thesis revealed that infectious diseases can result in major demographic and genetic changes in host populations over relatively few generations and short time-scales. Results showing dramatic and ongoing population declines and very limited population compensation in DFTD-affected populations indicate that DFTD poses a significant extinction risk for wild devil populations. Hence, this study confirms that host-specific pathogens can pose a significant extinction risk for wild species, even in the absence of alternate reservoir hosts, a finding critical to our understanding of host-pathogen dynamics. My thesis also highlights the potential negative interplay between disease susceptibility and host genetic variability, which is of utmost importance to the management of novel wildlife epizootics and the conservation of threatened wildlife in general. The thorough understanding of the ecology and impacts of DFTD in the wild obtained in this study has provided a solid base from which to both rigorously assess the outcome of management strategies and also formulate recommendations for the management of this disease in the wild. The lack of evidence for successful control of the DFTD epidemic in a wild population during the first phase of a selective culling experimental adaptive management approach, points to the need to implement a multi-faceted disease management program when attempting to control a novel infectious disease in the wild. By drawing on the lessons learnt in this case study I show that it is possible to establish a set of general guidelines for the future management of infectious diseases in threatened wildlife.
126

Badger social networks and their implications for disease transmission

Steward, Lucy Charlotte January 2016 (has links)
Diseases that infect wildlife populations pose a significant threat to public health, agriculture, and conservation efforts. The spread of these diseases can be influenced by the social structure of the population, and therefore often need to be accounted for in disease models. In this thesis I use high-resolution contact data to explore the social structure of a high-density population of European badgers (Meles meles). I explore how this structure might influence the spread of bovine tuberculosis (bTB), a debilitating disease of cattle for which badgers are a wildlife reservoir. Denning and home range data collected using radio tracking is also used to determine how this social structure is related to badger space use. I use social network analysis to identify the community structure of the badger population, revealing that badgers interact in fewer, more distinct groups than previously assumed. This is likely to inhibit the spread of disease through the population, given that the probability of infection entering a new social group will be reduced. However, among-group contact is still found to occur even between the most isolated groups. I show that this among-group contact is more likely to occur between less related individuals, possibly suggesting that breeding behaviour may drive among-group contact as a mechanism for inbreeding avoidance. To gain additional insight into this among-group contact, I determine how badger spatial behaviours are related. I show that the use of dens (setts) away from the social group’s main sett (outlier setts) in the spring is associated with extra-territorial ranging. I also show that this extra-territorial ranging is associated with more central network positions. The seasonality of this behaviour further suggests that this may be related to breeding activity. These findings suggest that behaviours associated with extra-group ranging may increase the risk of acquiring and transmitting infection. Therefore, use of outlier setts in the spring could act as a spatial proxy to identify high-risk individuals for disease spread, offering potential targets for disease control. Finally, I discuss the implications of these findings in regard to what they reveal about badger behaviour, disease transmission, and the design of effective disease control strategies. The importance of understanding population social structure for the study of wildlife disease in general is also discussed.
127

Compliance among members registered for the asthma disease risk management programme of a particular medical aid scheme

Opedun, Ntombombuso 31 December 2007 (has links)
The study sought to identify reasons for non-compliance among a particular medical aid scheme's members and their dependants registered for the asthma disease risk management (DRM) programme. A quantitative descriptive study was undertaken, using postal questionnaires. The research results indicated that most asthma patients were not compliant with the DRM programme because they lacked knowledge about the programme. Asthma patients' compliance with the DRM programme can be enhanced by health providers' and case managers' positive attitudes, better promotion of the programme, and by involving the patients in managing their illnesses. Asthma patients require education about healthy lifestyles, empowering them to successfully manage their condition, preventing asthma attacks and/or hospital admissions. When asthma is well-managed the patients' quality of life and general wellbeing will improve and the medical aid scheme's costs will be contained. / HEALTH STUDIES / MA (HEALTH STUDIES)
128

Caracterização e manejo do patossistema erva-mate / podridão-de-raízes / Characterization and management of the pathosystem erva-mate / root-rot

Poletto, Igor 02 August 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Erva mate (Ilex paraguariensis A. St.-Hil.) is a species widely cultivated in southern Brazil and adjacent countries, whose leaves and fine branches, appropriately prepared, offer the mate-tea, the most popular tea consumed in Brazil and exported to all over the world. root-rot is the main disease of this species in Brazil and may attack plantules and seedlings in nurseries as well as adult trees in orchards. The disease is caused by Fusarium spp., besides Pythium sp. and Rhizoctonia sp. causing serious damages due to the root system destruction, it causes, in the most serious cases the death of the plant. The incidence and the severity of the disease might be influenced by the cultivation methods and management of the orchard, with the use of mineral fertilizers without any technical criteria or the absence of fertilization, soil liming and orchards cultivation under the sun. In order to verify such hypothesis, 25 rural estates were marked in different counties of Vale do Taquari area in the state of Rio Grande do Sul BR. These areas had some orchards with symptoms of the disease and others in healthy conditions. Information about the crop and management characteristics, as well as soil for chemical and biological analysis, were collected and correlated through Pearson and outspread in direct and indirect effects through Path Analysis. In the nurseries, the disease incidence might be correlated to the contamination of the seed and the transmitted pathogens besides causing the death of the seedling may also have been transmitted to health seedlings, and they might had been transported to the field, contaminated areas which were previously free from the pathogen. Some practices applied by the farmers may cause the increase in the incidence of pathogens in the seeds and seedlings. In order to verify such hypothesis, some nurseries have been selected in the area of Vale do Taquari RS, where some samples of seeds, plantules, seedlings and substrata were collected in order to analyze the inoculation potential of the pathogens in each sort of sample. From the analysis of the substrata, seeds, seedlings different fungi colonies of the genre Fusarium were isolated, purified and stored for pathogenicity tests and, Trichoderma, for isolated selection with potential Fusarium antagonist. Moreover, experiments were installed in 2 nurseries, aiming at testing the benefits of commercial chemical (Captan SC®) and biological (Agrotrich® e Trichodel®) products, in the seed treatment, aiming at controlling the incidence of the disease on the seedbed. In the orchards, among the studied variables, it was noticed that the organic matter is the most influential over the Fusarium population in the soil and a linear positive correlation was obtained. Besides this variable, the calcium and phosphorus contends also have some sort of influence over the Fusarium population, however, in a less significant way. In the nurseries, the high percentage of seeds contaminated by Fusarium and Rhizoctonia was noticed. It was also noticed that the contamination begins in the flower and fruit phase. It was also observed that the technique of seed processing and stratification applied by the farmers, contribute to the increase in the incidence of pathogens. Besides the seeds, it was also noticed that the plantules and seedlings at the end of the nursery cycle, present pathogen contamination in their roots, although they did not present root-rot symptoms. The products Captan SC®, Agrotrich® and Trichodel® applied on the seed treatment, before the sowing, were not efficient in the Fusarium and Rhizoctonia control. In the Trichoderma spp. selection as potential antagonist to Fusarium, it was observed that SP-SFE-T1 isolated present high antagonic potential in in vitro tests. / A erva-mate (Ilex paraguariensis A. St.-Hil.) é uma espécie amplamente cultivada no sul do Brasil e países vizinhos, cujas folhas e galhos finos, preparados segundo método apropriado, fornecem o mate ou chimarrão, o mais popular chá consumido no Brasil e exportado para todo o mundo. A podridão-de-raízes é a principal doença da espécie no Brasil, podendo atacar plântulas e mudas no viveiro, bem como, árvores adultas em ervais. A doença é causada por Fusarium spp., além de Pythium sp. e Rhizoctonia sp. e provoca sérios danos decorrentes da destruição do sistema radicular, ocasionando, nos casos mais graves, morte da planta. Suspeita-se que a incidência e a severidade da doença são influenciadas pelos métodos de cultivo e por práticas de manejo do erval, como aplicação de adubos minerais sem critérios técnicos ou ausência de adubação, calagem do solo e cultivo de ervais a pleno sol. Para verificar tal hipótese, foram demarcadas 25 propriedades rurais, em diferentes municípios da região do Vale do Taquari-RS, as quais possuíam ervais com sintomas da doença, e outras com ervais sadios. Nesses ervais, foram coletadas informações a respeito das características de cultivo e manejo, assim como, solo para análise química e biológica. Estas informações foram correlacionadas entre si através da correlação de Pearson e desdobradas em efeitos diretos e indiretos através da Análise de Trilha. Nos viveiros, suspeita-se que a incidência da doença está correlacionada à contaminação das sementes utilizadas e que, patógenos transmitidos por sementes, além de causar mortalidade de mudas, podem ser transmitidos a mudas sadias e, estas, serem transportadas para o campo, contaminando áreas livres do patógeno. Além disso, algumas práticas utilizadas pelos viveiristas podem ocasionar aumento da incidência de patógenos nas sementes e mudas. Para verificar tal hipótese, foram demarcados viveiros na região do Vale do Taquari-RS, onde foram coletadas amostras de sementes, de plântulas, de mudas e de substrato para analisar o potencial de inóculo de patógenos presente em cada tipo de amostra. A partir das análises do substrato, das sementes e das mudas, diferentes colônias de fungos do gênero Fusarium foram isoladas, purificadas e armazenadas, para testes de patogenicidade e, Trichoderma, para seleção de isolados com potencial antagonista ao Fusarium. Além disso, foram instalados experimentos, em dois viveiros, a fim de testar a eficiência dos produtos comerciais, químico (Captan SC®) e biológico (Agrotrich® e Trichodel®), no tratamento de sementes, visando o controle da incidência da doença nas sementeiras. Nos ervais, entre as variáveis estudadas, verificou-se que a matéria orgânica é a que mais influencia na população de Fusarium do solo, obtendo-se uma correlação linear positiva. Além desta variável, os teores de cálcio e de fósforo no solo também exercem certa influencia na população de Fusarium, mas de forma menos significativa. Nos viveiros, constatou-se alta porcentagem de sementes contaminadas por Fusarium e Rhizoctonia e que, a contaminação começa já na fase de flores e frutos. Observou-se também, que a técnica de beneficiamento e estratificação das sementes, utilizada atualmente pelos viveiristas, contribui para o aumento da incidência de patógenos. Além das sementes, observou-se que plântulas e mudas no final do ciclo de viveiro, apresentam contaminação por patógenos nas suas raízes, mesmo que não apresentavam sintomas de podridão-de-raízes. Os produtos Captan SC®, Agrotrich® e Trichodel® utilizados no tratamento das sementes, previamente a semeadura, não foram eficientes no controle de Fusarium e Rhizoctonia. Na seleção de Trichoderma spp. com potencial antagonista ao Fusarium observou-se que o isolado SP-SFE-T1 apresentou alto potencial antagônico em testes in vitro .
129

Gestion des bio-agresseurs et réduction des pesticides en culture de laitue sous abris froids : apports croisés d’expérimentations factorielles et systémiques / Pesticide reduction and management of lettuce pests and pathogens

Barrière, Virginie 06 March 2015 (has links)
La réduction de la dépendance aux pesticides des systèmes de culture de laitue constitue un objectif à relativement court terme, partagé par les pouvoirs publics et les acteurs de la filière de production. Atteindre cet objectif suppose de disposer de moyens techniques permettant de substituer aux pesticides d’autres méthodes limitant les dégâts de bio-agresseurs de la laitue.Ces techniques peuvent être destinées à minimiser l’entrée d’inoculum dans les parcelles, à limiter la propagation des bio-agresseurs, à diminuer la sensibilité des plantes, ou à éradiquer les bio-agresseurs présents sur les cultures. L’évolution des systèmes de culture repose sur la démonstration de l’efficacité, en termes de protection des plantes, de ces techniques alternatives aux pesticides lorsqu’elles sont intégrées et combinées dans les itinéraires techniques. Elle dépend aussi de l’impact socio-économique et environnemental des itinéraires techniques alternatifs, dans un contexte commercial et réglementaire exigeant. L’objet de cette thèse a été de développer des stratégies alternatives de gestion des bio-agresseurs de la laitue d’hiver cultivée sous abri froid,plus économes en pesticides, et d’évaluer leurs performances agronomiques, économiques et environnementales,garantes de la durabilité des systèmes de production.Sur la base des techniques déjà disponibles, deux stratégies alternatives, nommées stratégie intermédiaire et stratégie bas-intrant ont été conçues, et testées dans deux exploitations agricoles et un domaine expérimental de l’INRA pendant deux hivers, en comparaison avec une stratégie conventionnelle, représentative des pratiques actuelles. Les stratégies intermédiaire et bas-intrant ont permis de réduire de 32% et 48% l’usage des pesticides, respectivement, et ont été suffisamment efficaces pour obtenir une qualité visuelle et des rendements équivalents à la stratégie conventionnelle. Le bénéfice environnemental de leur mise en oeuvre a également été démontré. La mise en place de ces stratégies a cependant entrainé un surcoût de production,essentiellement lié à la lutte biologique, d’environ 10 à 13%. Parallèlement, deux orientations techniques originales, dont l’efficacité n’était pas caractérisée, ont été explorées. Une première série d’essais expérimentaux a porté sur l’influence du génotype de l’hôte et de l’environnement de la plante sur sa sensibilité à deux champignons pathogènes d’importance majeure, Botrytis cinerea et Sclerotinia sclerotiorum. Il a été montré que le choix d’un génotype moins sensible couplé à une optimisation du rapport fructose : saccharose de la plante diminuait les symptômes observés après inoculation. Une deuxième démarche expérimentale, portant sur la lutte biologique contre le puceron Nasonovia ribisnigri, a révélé l’incapacité de parasitoïdes du genre Aphidius à contrôler les pucerons en fin de culture, lorsque la structure du couvert végétal devient trop complexe.En plus d’inscrire ces travaux de recherche dans un processus d’amélioration continue de l’efficacité et des performances des stratégies alternatives aux pesticides, la démarche scientifique utilisée, articulant approche analytique et approche intégrative, a permis d’étudier des techniques ayant potentiellement un impact sur plusieurs bio-agresseurs, telles que la réduction de la fertilisation azotée ou l’optimisation de l’espacement entre les laitues, qui pourraient permettre une meilleure gestion des pathogènes responsables de la pourriture du collet et des pucerons. / The reduction of pesticide reliance in lettuce cropping systems is a short term objective sharedby public authorities and by the stakeholders of lettuce market. Reaching this goal implies thesubstitution of pesticides by others techniques which may limit pest and pathogen damage. Thesetechniques can be intended to mitigate pest and pathogen invasion or propagation, to increaseplant defenses or to remove pests and pathogens from the crop. The improvement of currentcropping systems relies on i) the demonstration of the ability of alternative techniques to managediseases and pests when they are combined and integrated during the crop cycle; ii) theassessment of the socio-economic and environmental impacts of alternative strategies in a stringentcommercial and regulatory context. The objective of this thesis was to design alternativestrategies for pest and pathogen management of lettuce grown in winter under shelter, with fewerpesticide applications, and to assess their agronomic, economic and environmental performancesso as to ensure the sustainability of production.Based on currently available techniques, two alternative strategies, called intermediate andlow-input, were designed, and tested in two farms and an INRA experimental station duringtwo winters and compared to a conventional strategy representing current practices. The alternativestrategies enabled to reduce pesticide applications by 32% and 48% respectively. Theywere efficient enough to obtain similar yield and quality as compared to the conventional strategy.The environmental benefits of their implementation were also demonstrated. However, thesestrategies required a 10-13% extra production costs, almost exclusively due to biological controlproducts.In parallel, two original technical orientations, which efficacy had not been previously described,were examined. In a first set of experiments, the impact of lettuce genotype and growthconditions on plant susceptibility to two major pathogens, Botrytis cinerea and Sclerotinia sclerotiorum,was investigated. The use of a genotype displaying low susceptibility to these fungi,associated with an optimization of the ratio of fructose : sucrose in plants, appeared to reducethe symptoms after inoculation. A second experimental approach, dealing with biological controlagainst the aphid Nasonovia ribisnigri, highlighted the inability of Aphidius parasitoids tocontrol aphid populations at the end of the crop cycle, when the canopy structure becomes toocomplex.In addition to a contribution to cropping systems improvement, the scientific method used,combining analytical and integrative approaches enabled us to highlight the effect of techniquesacting on several pests and/or pathogens, such as the reduction of nitrogen fertilization or theoptimization of plant spacing, which could improve the management of fungi causing basal rotas well as aphids.
130

Improving Disaster Preparedness and Planning for Chronic Disease Populations

Gichomo, Gladys N 01 January 2019 (has links)
The significant rise of both chronic diseases and disasters in the last 20 years and the healthcare outcomes of individuals with chronic diseases during and in the aftermath of disasters have raised concerns among public health practitioners, healthcare providers, the U.S government, and the general public. Researchers have indicated that during disasters, the health outcomes of individuals with chronic diseases are significantly unfavorable compared to the general public. However, there is inadequate information on the management of chronic diseases, quality of care, and resource identification and allocation by disaster responders. This qualitative, grounded theory study, explored how the study participants addressed chronic disease needs during and after disasters. A total of 15 adult disaster relief responders who had been involved in disaster planning, response, or care management of individuals with chronic diseases, were recruited through snowballing, public/bulleting postings, and social media. Using the ecological model of disaster management allowed the identification of individual and societal influences that hinder disaster preparedness and chronic disease management. Data collection consisted of semistructured in-depth open-ended interview questions, allowing participants to share their lived experiences. Data were analyzed through open, axial, and selective coding and managed using the Atlas ti8 software. The findings supported the ecological model of disaster management and strategies such as the use of special needs shelters during impending disasters. Such strategies could enhance disaster preparedness and planning efforts and potentially improve health outcomes during and after disasters.

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