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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.
251

Produtividade e controle de podridão radicular na cultura da mandioca (Manihot esculenta) com o uso de Trichoderma spp / Productivity and control of brown streak in cassava culture (Manihot esculenta) using Trichoderma spp

Stefanello, Luciano 29 August 2016 (has links)
Made available in DSpace on 2017-07-10T17:37:23Z (GMT). No. of bitstreams: 1 Luciano_Stefanello.pdf: 1381556 bytes, checksum: 6bd57829a5462b5319b07e3a1fb7ba7a (MD5) Previous issue date: 2016-08-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Cassava culture has great importance for agriculture and for populations mainly those in development, for being a culture with high rusticity and productivity, but diseases have been reducing the productivity and invalidating croplands, as in the case of root rot. Therefore the aim of this study was to investigate the potential of Trichoderma to control root rot in cassava caused by Fusarium and Phytophthora, and to investigate the ability of Trichoderma to promote the development of culture and the use of Trichoderma combined with different varieties in both systems. Initially in vitro tests were performed with 23 isolates of Trichoderma spp., the pair of test cultures, production of volatile and non-volatile antimicrobial compounds, against Phytophthora drechsleri development and Fusarium solani, under field conditions cassava planting was realized using the range Fécula Branca in conventional system where at planting was performed spraying spore suspension six of Trichoderma isolates on cuttings in the planting furrow. A second experiment was performed in two culture systems with two varieties with and without Trichoderma harzianum application. For nonvolatiles antimicrobial compounds the isolate studied presented a high ability to reduce mycelial growth of P. drechsleri and F. solani with inibiting up to 100%, to evaluate nonvolatiles antimicrobial compounds produced by Trichoderma the results were less expressive with the maximum inhibition value of 23,87%. for the first experiment under field conditions,the isolated TLB 14 promoted a better root development, consequently providing more productivity, for the incidence of disease the isolates TOD2A, TLB14 and TI2 presented lower incidence. for the second experiment under field conditions, about the plant stand it was lower in range Baianinha and using T. harzianum, the incidence of brown streak was lower in conventional tillage and the productivity was higher in convencional tillage and using T. harzianum / A cultura da mandioca possui grande importância para as populações principalmente aquelas em desenvolvimento, por ser uma cultura com alta rusticidade e produtividade. No entanto doenças vem reduzindo a produtividade e inviabilizando áreas de cultivo como é o caso das podridões radiculares. Portanto o objetivo deste trabalho foi verificar o potencial de Trichoderma em controlar podridão radicular na mandioca causada por Fusarium e Phytophthora, além de investigar a capacidade do Trichoderma em promover o desenvolvimento da cultura e o uso de Trichoderma combinado com diferentes variedades em dois sistemas de cultivo. Inicialmente testes in vitro foram realizados com 23 isolados de Trichoderma spp., pelos testes de pareamento de culturas, produção de compostos antimicrobianos voláteis e não voláteis, frente ao desenvolvimento de Phytophthora drechsleri e Fusarium solani. Em condições de campo o plantio de mandioca foi realizado utilizando a variedade Fécula Branca em sistema convencional efetuando-se pulverização de suspenção de esporos de seis isolados de Trichoderma sobre as manivas dentro do sulco de plantio. Um segundo experimento foi realizado em condições de campo em dois sistemas de cultivo com duas variedades (IAC 90 e Baianinha) com e sem a aplicação de Trichoderma harzianum. Para compostos antimicrobianos não voláteis os isolados estudados apresentaram uma alta capacidade em reduzir o crescimento micelial de P. drechsleri e F. solani com inibição de até 100 %. Para a avaliação de compostos antimicrobianos voláteis produzidos por Trichoderma os resultados foram menos expressivos com valor de inibição máximo de 23,87 %. Para o primeiro experimento em condição de campo o isolado TLB 14 promoveu um melhor desenvolvimento radicular, consequentemente proporcionando maior produtividade, para a incidência de doença os isolados TOD2A, TLB14 e TI2 foram os que reduziram a incidência em raízes de mandioca. Para o segundo experimento em condições de campo, quanto ao estande de plantas ele foi menor na variedade Baianinha e com o uso de T. harzianum. A incidência de podridão radicular foi menor em sistema de plantio convencional e a produtividade foi maior em sistema de plantio convencional e com o uso de T. harzianum
252

Reação de resistência à giberela em cultivares de trigo (Triticum aestivum L.), avaliada em condições de campo e casa de vegetação / Reaction of resistance to FHB in wheat cultivars (Triticum aestivum L.) evaluated under field and greenhouse conditions

Alves, Rafael Hansen 30 June 2010 (has links)
Made available in DSpace on 2017-07-10T17:37:39Z (GMT). No. of bitstreams: 1 Rafael_Hansen_Alves.pdf: 691556 bytes, checksum: 76623d639903f7b4404dca73bdfe4314 (MD5) Previous issue date: 2010-06-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Caused by several species of fungus, fusarium head blight (FHB) is a disease of great economic importance in wheat (Triticum aestivum L.), causing large losses in world grain production. In Brazil the main species of fungi responsible for disease is Gibberela zeae (Schwabe.), and its the anamorphic Fusarium graminearum (Schwabe). The control by chemical treatment of the disease with the use of fungicides has low efficiency due to the difficulty of identifying the exact time of application. Therefore, the use of resistant varieties is shown as a safe and economically viable alternative for the production of wheat scab-free. To contribute to the understanding of the behavior of some Brazilian wheat cultivars for FHB, the objectives were to assess the presence or absence of reaction to FHB resistance in wheat cultivars under inoculation in field conditions and greenhouse; and identify what kind of reaction that is acting (resistance type I or type II resistance). The proposed work was developed in the field, greenhouse and laboratory. Two methodologies inoculation were applied, depending on the type of resistance to be tested, and the targets of this work were to evaluate the resistance type I and type II resistance. Twenty eight genotypes with different responses to FHB resistance were used to both evaluations. The resistance of type I was measured by spraying the spikes with suspension. In the field, dispersal of inoculum in the area was used wheat grains colonized with perithecia previously inoculated. The assessment of disease severity in the 28 cultivars was made 21 days after inoculation (DAI), the green ear stage, taking on a note on a linear scale from zero to 100, based on the scale suggested by Stack and McMullen. The evaluation of resistance of type II was performed only in the greenhouse. Obtaining spore mass acquisition was performed by scraping the plates with PDA medium colonized by Fusarium graminearum. Conidia were washed with distilled water and received the inoculum. The concentration was adjusted to 5x104 spores per mL. The count was performed by an optical microscope with the aid of a Neubauer chamber. About 10μL of the suspension of spores (macroconidia) at a concentration of 5x104 mL-1 was injected between the lemma and palea of a spikelet located at the point of infection, on both sides of the ear, using a hypodermic syringe. Evaluations were performed at 7, 14 and 21 days after inoculation by counting the spikelets with symptoms of the disease, excluding the two infected spikelets. The FHB occurred in two periods in the field with greater variation among the 28 cultivars tested in the first season. For resistance type I, nine and nineteen cultivars had the lowest severity, respectively, in field and greenhouse conditions, showing that they are sources of resistance. In accessing the resistance of type II, BRS Umbu, CEP Nova Era, CEP Raizes, BRS 208 e Frontana not proved to be sources of resistance. Already BRS Guamirim, CD 120, Onix, Rubi, CEP 50, BRS 179, Pampeano, Abalone, CD 114, IPR 85, Safira, BRS Louro, CD 117, CDF 2002116, CD 115, BRS177, CD 0529 and BRS Camboim showed the lowest values for AUDPC thus demonstrating the potential for type II resistance to FHB / Causada por diversas espécies de fungo, a giberela e uma doença que possui grande importância econômica na cultura do trigo (Triticum aestivum L.), ocasionando perdas sensíveis na produção mundial de grãos. No Brasil a principal espécie de fungo responsável pela moléstia e Gibberela zeae (Schwabe.), sendo sua forma anamófica Fusarium graminearum (Schwabe). O controle através de tratamento químico da doença com o uso de fungicidas apresenta baixa eficiência devido a dificuldade de identificação do momento exato da aplicação. Portanto, a utilização de variedades resistentes mostra-se como uma alternativa segura e viável economicamente para a produção de trigo livre de giberela. Visando contribuir para o conhecimento do comportamento de algumas cultivares brasileiras de trigo em relação a giberela, os objetivos deste trabalho foram avaliar a presença ou ausência da reação de resistência a giberela em cultivares de trigo, sob inoculação em condições de campo e casa de vegetação; e identificar qual e o tipo de reação que esta atuando (resistência tipo I ou resistência tipo II). O trabalho proposto foi desenvolvido a campo, casa de vegetação e em laboratório. Foram utilizadas duas metodologias de inoculação, conforme o tipo de resistência a ser testada, sendo que, foram alvo do presente trabalho a avaliação da resistência tipo I e resistência tipo II. Para ambas as avaliações foram utilizadas 28 genótipos de trigo com diferentes reações de resistência a giberela. A resistência do tipo I foi medida através da inoculação de plantas em casa de vegetação, através de borrifamento das espigas, com suspensão de esporos. No campo, para dispersão do inoculo na área foi utilizado grãos de trigo colonizados com peritécios previamente inoculados. A avaliação da severidade da doença nos 28 cultivares foi feita 21 dias apos a inoculação (DAI), no estádio de espiga verde, atribuindo-se uma nota em uma escala linear de zero a 100, baseada na escala sugerida por Stack e McMullen. A avaliação da resistência do tipo II foi realizada somente em casa de vegetação. A obtenção de esporos em massa foi realizada através da raspagem de placas com meio BDA colonizadas por Fusarium graminearum. Os conídios foram lavados com água destilada e obtido o inoculo. A concentração foi ajustada para 5x104 esporos por mL. A contagem foi realizada em microscópio óptico com o auxilio da Câmara de Neubauer. Aproximadamente 10μL da suspensão de esporos (macrogonídios) na concentração de 5x104 mL-1 foi injetada entre a lema e a palea de uma espigueta localizada no ponto de infecção, nos dois lados da espiga, utilizando uma seringa hipodérmica. As avaliações foram realizadas aos 7, 14 e 21 dias apos a inoculação, contando-se as espiguetas com sintomas da doença, excluindo as duas espiguetas que foram inoculadas. A giberela ocorreu nas duas épocas a campo com maior variação entre as 28 cultivares testadas na primeira época. Para a resistência do tipo I nove e dezenove cultivares obtiveram os menores valores de severidade, respectivamente, em campo e em casa de vegetação, demonstrando serem fontes de resistência. Na avaliação da resistência do tipo II, as cultivares BRS Umbu, CEP Nova Era, CEP Raízes, BRS 208 e Frontana não demonstraram serem fontes de resistência. Já as cultivares BRS Guamirim, CD 120, Onix, Rubi, CEP 50, BRS 179, Pampeano, Abalone, CD 114, IPR 85, Safira, BRS Louro, CD 117, CDF 2002116, CD 115, BRS 177, CD 0529 e BRS Camboim apresentaram os menores valores para AACPD demonstrando assim, potencial para a resistência do tipo II a giberela
253

Risk factors for adolescent caries incidence in the Iowa Fluoride Study

Yaduwanshi, Kalyani Raj 01 December 2014 (has links)
Objective: To determine risk factors for cavitated caries incidence and extent of cavitated caries among adolescents. Methods: Three hundred and three Iowa Fluoride Study (IFS) subjects met inclusion criteria for interval between dental examination and the responses from the IFS (ages 13.5 to 17.0) and the Block Kids Food Frequency (ages 13.0 to 17.0) questionnaires, respectively. The analyses focused on the outcome variables of net cavitated caries incidence and net cavitated caries increment counts, respectively. The independent IFS questionnaire variables related to demographics, fluorides, oral hygiene, beverage intakes, dental visits, sealants and previous caries incidence variables, respectively, whereas, Block's questionnaire variables related to intakes of solid foods and beverages, respectively. Two sets of analyses, logistic and negative binomial regression analyses, were conducted to assess the associations between risk factors and net cavitated caries incidence and increment counts from 13 to 17, respectively. Results: In multivariable logistic regression analyses, significant (p<0.05) negative associations were found between age 13 to 17 net cavitated caries incidence and greater frequency of consumption of vegetables, greater brushing frequency and greater frequency of sugar-free beverage consumption. Additionally, significant (p<0.05) positive associations were found between age 13 to 17 net cavitated caries incidence and both net cavitated caries incidence from 9 to 13 and frequency of consumption of solid-foods in the combined category of presumed moderate cariogenicity. The significant interaction effect showed that the effect of the presence/ absence of sealants varied for girls vs. boys. In multivariable negative binomial analyses assessing the association between net cavitated caries increment count from 13 to 17 and risk factors, significant (p<0.05) positive associations were found with greater intake of foods predominant in starch, presence of sealants, greater baseline age, cavitated caries increment count from 9 to 13, and greater frequency of consumption of foods predominant in added sugar, respectively. Significant (p<0.05) negative associations were found between net cavitated caries incidence and greater frequency of consumption of foods predominant in fiber and natural sugar and greater daily fluoride intake from water. However, daily fluoride intake from water was not statistically significant with the significant interaction effect included between baseline age and net cavitated caries increment count from 9 to 13 (dichotomized as Y/N). Conclusion: Presence of sealants, frequency of consumption of vegetables and previous cavitated caries incidence from 9 to 13 were associated with outcomes of incidence and extent of cavitated caries observed among IFS adolescents. The differences in findings for risk factors for incidence and extent of cavitated caries are due in part to the nature of the outcome variables (count vs. dichotomous), emphasizing the need to consider both outcomes in future studies of adolescent caries.
254

Photocatalysis and Grazing-Ion Beam Surface Modifications of Planar TiO2 Model Systems

Luttrell, Timothy 04 April 2014 (has links)
This dissertation is related to the understanding of catalytic reactions of metal oxides. For several decades, the surfaces and bulk of materials have been probed to determine additional properties that relate to photocatalytic applications. This investigation furthers these efforts by the (a) modification of a metal oxide surface to isolate known influences of chemical properties and (b) proposing and utilizing a novel methodology for attribution of photocatalytic activity to a discernable influence. For the first effort, by effectively utilizing a known technique for a new application on a metal oxide, such isolations can be made despite unfavorable states. For the second effort, a reduction in the influence of surface states for metal oxides is effectively performed, providing the isolation of influences originating from the bulk. The challenge with such a proposal is verifying such bulk states have been adequately isolated as external influences would obviously distort any conclusions. Thus, techniques to both create such bulk states and eliminate unwanted combinations thereof are additionally required and must be provided for. Lastly, a determination of the photocatalytic activity is made to these states and results are provided.
255

Association Between Altitude and Bronchopulmonary Cancer

Ching, Hung 01 January 2018 (has links)
As a validation study, this study addressed an under-researched area of bronchopulmonary cancer mortality and incidence. The association between altitude and bronchopulmonary cancer mortality and incidence was investigated using data from the Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research. The theoretical framework for my study was Bronfenbrenner's ecological model. This model emphasizes the relevance of social and physical environments that influence patterns of disease and injury and shape responses to these patterns of disease and injury. The age-adjusted bronchopulmonary cancer mortality and incidence rates per 100,000 people in the highest elevation and lowest elevation states were investigated. The data used in this study spans from 2006 to 2014. In this study, bivariate statistics were used to analyze the data. The relevant technique of performing an unpaired t-test was used. After performing age, gender, and race-stratified analysis, no significant difference in cancer mortality and incidence was found within the following three groups: Black or African American, Asian or Pacific Islander, and American Indian or Alaska Native. This was a new finding, as previous studies did not stratify for race. Cancer mortality and incidence were found to be lower in both the male and female groups for the highest elevation states. Cancer mortality and incidence were also found to be lower in all age categories for the highest elevation states. A positive social change impact of this study is that this research provides the groundwork for future studies to probe what in the environment is lowering the bronchopulmonary cancer mortality and incidence for the White population.
256

Measuring the Incidence and Prevalence of cardiovascular Diseases In NIgeria

Adebiyi, Adenike 01 January 2017 (has links)
Cardiovascular disease (CVD) is a major contributor to chronic diseases. High blood pressure and other modifiable cardiovascular risk factors are on the increase in Nigeria. The purposes of this study were to (a) explore associations among high blood pressure, social economic status, and health status awareness and (b) measure the incidence and prevalence of cardiovascular diseases in 3 states of Nigeria: Lagos, Ekiti, and Ondo. Participants (N = 368) were selected through stratification and randomization. Data were collected in person with the aid of validated questionnaire, which measured socioeconomic status as well as other variables in Lagos, Ado Ekiti, Ijesa-Isu, and Akure. Logistic regression and correlation analyses showed no significant difference in the regional incidence and prevalence of cardiovascular disease (F (4, 362) = 1.23, p = 0.30); and there was no significant relationship between the health status variable and the standard of living variable. Due to the fact that only 3 out of 36 states were sampled, this study is not generalizable and some other cardiovascular diseases modifiable risks factors that were not measured could have reacted differently in analysis. This study's results set precedence by promoting cardiovascular health. When disseminated, the results of this study will help advocate for a change process that curtails cost and decreases the general burden of CVDs in other, similar areas. Recommendations include measuring this incidence and prevalence of CVDs in all 36 states of Nigeria and exploring the interactions between culture, religion, health, and beliefs.
257

Utility of death certificate data in predicting cancer incidence

Bedford, Ronald L 01 December 2009 (has links)
No description available.
258

Public health impact of contact lens related microbial keratitis

Keay, Lisa Jane, Optometry & Vision Science, Faculty of Science, UNSW January 2006 (has links)
This thesis describes the impact of contact lens-related microbial keratitis in terms of incidence and severity. Disease outcome is defined by visual outcome, costs to the healthcare system, costs to the individual and duration of disease. A successful 12-month surveillance study was conducted of the populations of Australia and New Zealand to detect all cases of contact lens-related microbial keratitis. A random telephone survey of 32,000 households in Australia and 7,500 in New Zealand accurately determined the level of use of various contact lenses in the community. The impact of new contact lens types: silicone hydrogels and daily disposables were investigated. Increased risk persisted in overnight wear with silicone hydrogel materials. Microbial keratitis associated with silicone hydrogel materials had slightly shorter disease duration however other factors had a stronger influence on severity. Rigid gas permeable and frequent replacement soft lenses when used for daily wear constitute the lowest risk. Cost analysis was developed in a hospital case series of microbial keratitis. This analysis was applied in the surveillance study including cases managed in the private health care sector. Disease duration and associated costs are novel indices of severity for contact lens-related disease. The most dramatic effects on disease severity were seen with the type of organism involved. Keratitis attributed to environmental organisms (Gram-negative bacteria, Acanthamoeba, fungi and Nocardia species) were 10x more likely to cause loss of visual acuity, had longer duration of symptoms and incurred higher costs. Importantly, delays in receiving treatment increased disease duration and associated costs. Greater awareness of the need for specialist healthcare is indicated amongst health care providers and contact lens wearers. The hypothesis that overnight wear in silicone hydrogel lenses would not increase the risk of infection has been disproven. This information is of value to practitioners who are responsible for informing contact lens wearers about the risk of contact lens-related infections and should be weighed against the benefits of continuous wear. The identification of factors which contribute to the outcomes of disease will be used in education campaigns amongst health care providers and contact lens wearers to minimise the impact of disease.
259

The relationship between training load and incidence of injury and illness over a pre-season at an Australian Football League Club

PIGGOTT, Benjamin, ben_piggott@yahoo.com January 2008 (has links)
In any competitive sporting environment, it is crucial to a team's success to have the maximum number of their players free from injury and illness and available for selection in as many games as possible throughout the season. The training programme of the club, and therefore training load, can have an impact on the incidence of injury and illness amongst the players. The purpose of this study was to investigate the relationship between the training load and the incidence of injury and illness over an entire pre-season at an Australian Football League (AFL) club. Sixteen players were subjects; all full time professional male AFL players (mean + or - standard deviation; age 23.8 + or - 5.1 years; height 188.9 + or - 7.4 m; weight 90.9 + or - 9.2 kg). A longitudinal research design was employed, where training load, injury and illness were monitored over a 15 week pre-season and Pearson Correlation Coefficients were used to examine relationships.
260

Détermination des contraintes résiduelles dans les revêtements par diffraction des rayons X en faible incidence

Peng, Jun 07 1900 (has links) (PDF)
Une nouvelle méthode d'analyse par diffraction des rayons X (DRX) en incidence rasante, notée sin2 *, a été développée pour répondre à la demande d'analyse du niveau et la distribution des contraintes résiduelles (CR) dans un revêtement. La méthode est basée sur la technique de DRX en faible incidence et elle tient compte des orientations cristallines et de la géométrie de mesure (l'angle d'incidence, les angles et de l'épaisseur de couche à analyser) afin de connaître la profondeur de pénétration exacte du faisceau incident. Par cette méthode, on peut non seulement évaluer le niveau moyen des CR dans le revêtement, mais également déterminer le gradient et la distribution en variant l'angle d'incidence pour différentes profondeurs de pénétration voulues. Les incertitudes de mesure ont été ensuite évaluées, et l'influence de la rugosité de surface a été étudiée avec des éprouvettes sous sollicitation mécanique connue. Un modèle analytique a été établi pour la correction de l'influence de la rugosité sur la détermination des CR. Par ailleurs, une éprouvette en alliage base nickel rectifiée avec un fort gradient de contrainte résiduelle a été étudiée en appliquant notre méthode sin2 * pour évaluer la sensibilité de la méthode développée. Deux séries d'échantillons de revêtements (Cuivre sur substrat Ni élaboré par le procédé PVD, et Tantale biphasé sur substrat Ti élaboré par le procédé CVD) ont été étudiées avec la nouvelle méthode d'étude afin d'analyser la distribution des CR. La comparaison des résultats avec deux autres méthodes a montré que cette nouvelle méthode d'évaluation par DRX en faible incidence est fiable et facile à utiliser pour déterminer le niveau et la distribution des CR.

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