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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.
91

Key factors influencing canine heartworm, Dirofilaria immitis, in the United States

Brown, Heidi, Harrington, Laura, Kaufman, Phillip, McKay, Tanja, Bowman, Dwight, Nelson, C., Wang, Dongmei, Lund, Robert January 2012 (has links)
An examination of the Companion Animal Parasite Council's (CAPC) canine heartworm data to clarify the spatial prevalence of heartworm in the United States. Factors thought to influence the spatial risk of disease, as identified in a recent CAPC workshop, are discussed.
92

Multiplicity of viral infection in brown algae

Stevens, Kim January 2014 (has links)
Brown algae are important primary producers and habitat formers in coastal environments and are believed to have evolved multicellularity independently of the other eukaryotes. The phaeoviruses that infect them form a stable lysogenic relationship with their host via genome integration, but have only been extensively studied in two genera: Ectocarpus and Feldmannia. In this study I aim to improve our understanding of the genetic diversity, host range and distribution of phaeoviruses. Sequencing and phylogenetic analysis of amplified fragments of three core phaeoviral genes (encoding major capsid protein (MCP), DNA polymerase and superfamily III helicase) of phaeovirus infected algae confirmed the suspected phaeoviral identity of viruses infecting E. fasciculatus, F. simplex, Pilayella littoralis, Myriotrichia clavaeformis and Hincksia hincksiae. Furthermore, this approach revealed multiple virus sequence variants within individual strains, and moreover that the variants formed two distinct subgroups. Subgroup A was highly conserved and observed in multiple algal genera, whereas subgroup B was much more diverse, but only found in Feldmannia species. Transcriptome sequencing of an actively infected F. irregularis strain revealed polymorphisms within key viral genes, suggesting that multiple variants were indeed active within this strain. High resolution melt curve (HRM) technology was used to develop a high throughput screening method for detecting phaeoviral MCP as a proxy for detection of phaeoviruses. This technique was also able to assign 88% of those detected to one of the subgroups, based on their differing melting temperature distributions. This was then applied to 1034 Ectocarpus isolates collected from around Europe and South America, and in accordance with previous studies of phaeoviral infection, 43-79% of strains contain virus sequence (depending on species). 17% of the isolates tested even contained sequence from both subgroups. 82 Laminariales strains, close relatives of the Ectocarpales, were also screened because they comprise commercially important kelp species but are not known to be infected by viruses. 10-17% of these tested positive for phaeoviral MCP, which when sequenced formed a separate group within the phaeoviruses. This finding could have a major impact on the kelp farming industry if the viruses are found to affect reproduction as happens in the Ectocarpales. The discovery of two subgroups is contrary to current beliefs that the phaeoviruses are a single monophyletic group, and that each species of alga has its own phaeovirus, casting doubt on the usefulness of the current convention of naming each phaeovirus after its host. It appears that the subgroup B viruses have begun to evolve away from the stable, K-selected subgroup A viruses towards a more r- type strategy with higher mutation and diversification. This study has identified potential mechanisms that may influence this shift, including mutations in a region of the DNA polymerase known to negatively affect DNA replication fidelity, combined with an active integrase and lack of a proofreading exonuclease, along with the observed infection of individuals with both phaeovirusal subgroups. The resulting mutations and recombinations could lead to the diversity observed here, and may provide a suitable model for the study of other emergent virus infections.
93

Obesity in the army : prevalence, correlates and prediction

Sanderson, Paul W. January 2014 (has links)
The emergence of obesity as a distinct disease could have far reaching consequences for an organisation where optimum health and physical fitness are required for personnel to perform their occupational roles effectively. The aim of this thesis is to increase our understanding of the prevalence, correlates and predictors of obesity in the British Army. Systematic review indicated a smaller body of knowledge in respect of the treatment and correlates of obesity in military populations. Successful treatment interventions incorporated exercise, healthy eating information, behavioural modification, self-monitoring, relapse prevention, structured follow-up and were supported by trained personnel. The major significant correlates of obesity were being enlisted personnel, male, ≥35 years of age, African-American/Hispanic ethnicity, and married (with spouse present). The review highlighted the deficit in knowledge concerning treatment, and correlates of obesity in military populations. The trend of escalating obesity has prompted some armed forces to report obesity trends and prevalence, the findings of which suggest that obesity is a growing concern in the armed services. A study based on the secondary analysis of data covering 50,000 British Army soldiers indicated that according to BMI, 56.7% of the study population were overweight and of those individuals 12% were obese. When waist circumference data were added to the BMI data, the results indicate that females displayed a higher percentage of risk of obesity related ill-health (a combination of BMI and waist circumference) than males (30.4% and 24% respectively). Further analysis suggested that age, marital status, rank and military employment category were significant correlates of obesity. Additionally, obesity and increased risk of obesity related-ill-health were linked to higher failure and lower attendance on British Army physical tests. Data suggested older army personnel (>30) had a higher pass rate, but a lower attendance rate. The final analysis of all available variables suggested physical test outcome, age, medical status and enlisted status were the most significant predictors of obesity. A final study based on a different study population (n=1124) from the high readiness component of the UK based British Army sought to identify relationships between health behaviours that were not supportive of healthy weight and to understand the predictive influence of individual and collective behaviour in relation to obesity and the risk of obesity related ill-health in military personnel. The investigation used a health behaviour questionnaire to assess health behaviours that might influence weight status. Final analysis of this highly active population suggested, restrained eating, food preparation in the working week, injury status, age, sedentary behaviour, leisure-time physical activity engagement and type of motivation for exercise were the most significant factors. This thesis highlights the lack of knowledge, and gives evidence to support the impact of obesity on individual health and collective occupational capability. Obesity is a complex multifaceted disease where no single causal route predominates. However, the identification of potential causal and predictive relationships will aid in the prevention and treatment of obesity in the British Army.
94

Impact of Family Focused Diabetes Intervention on Metabolic Risk Factors in 9 to 12 Year Old Youth

Ussery, Christopher Lee January 2016 (has links)
In the United States, approximately 1 in 3 children are overweight, and 1 in 5 obese, conditions associated with increased risk of metabolic disorders including type 2 diabetes. Treatment of type 2 diabetes is costly and not always effective, thus, prevention offers the best course of "treatment." However, few diabetes prevention programs are accessible to at-risk children, or involve their caregivers. The E.P.I.C. Kids study is a family-focused community-based diabetes prevention program developed in partnership with the YMCA of Southern Arizona, targeting 9-12-yr-olds at risk of diabetes, and led by YMCA lifestyle coaches. In this 12-week pilot study, we assessed the metabolic risk of participants and investigated changes in metabolic biomarkers following the intervention.
95

Nutritional Screening of Older Adults : Risk Factors for and Consequences of Malnutrition

Söderström, Lisa January 2016 (has links)
Aims The overall aim of this thesis was to extend current knowledge about the prevalence of malnutrition, to identify possible risk factors for development of malnutrition, and to describe the consequences of malnutrition in relation to all-cause and cause-specific mortality among older adults admitted to hospital. Methods The prevalence of malnutrition was estimated in a cohort of 1771 older adults (≥65 years) who were admitted to a Swedish hospital during 2008–2009 (15 months) and screened for malnutrition using the Mini Nutritional Assessment (MNA) instrument. Possible risk factors for malnutrition were recorded during the hospital stay (Study I). Dietary intake 10 years earlier (in 1997) was collected for 725 of these older adults (Study II). All-cause (Study III) and cause-specific (Study IV) mortality were followed up after medians of 3.5 and 5.1 years, respectively, for 1767 of the participants. Results The prevalence of malnutrition was 9.4% while 55.1% were at risk of malnutrition. Risk factors for malnutrition was an overnight fast >11 hours, <4 eating episodes a day, and not cooking independently. In middle-aged and older adults with a body mass index <25 kg/m2 in 1997, the risk of malnutrition increased for each additional percentage point of energy from total, saturated and monounsaturated fat at follow-up after 10 years. Malnourished older adults had almost four times higher risk of death during follow-up, while those at risk of malnutrition had a 56% higher risk, compared to well-nourished. Furthermore, well-nourished older adults had consistently lower risk of death, regardless of the cause of death. Conclusions Only 35.5% of older adults admitted to hospital were well-nourished. The identified risk factors could be used in interventions aimed at preventing malnutrition. Normal-weight and underweight middle-aged and older adults should consider limiting the intake of total fat and/or improve the quality of the fat in the diet in order to decrease the risk of becoming malnourished later in life. Malnutrition and risk of malnutrition were associated with increased overall and cause-specific mortality. These relationships emphasize the need for nutritional screening to identify individuals who may require nutritional support in order to avoid preterm death.
96

Assessment of Hypertension and Military Deployments

Granado, Nisara Suthun January 2008 (has links)
Introduction: High-stress situations, such as military deployments, may be a risk factor for hypertension. The relationship between the stress triggered by combat deployment and hypertension is unknown. Acute stress from combat conditions can cause a temporary rise in blood pressure, which decreases within hours or days. Cross-sectional studies have shown no association between hypertension and deployment to the 1991 Gulf War or to Vietnam. Self-reported hypertension often is used as an outcome in large population studies. Fair to substantial agreement has been observed between self-reported hypertension and various sources of administrative data, medical records, and blood pressure measurements. The goal of this dissertation was to determine whether recent deployment to Iraq and Afghanistan was associated with new-onset hypertension.Methods: Baseline Millennium Cohort Study questionnaires (July 2001 to June 2003) were completed by 77,047 individuals. Follow-up questionnaires (June 2004 to February 2006) were completed by 55,021 responders. The relationship between new-onset hypertension and history of a recent military deployment was assessed through multivariable logistic regression (N=37,075). Baseline data were analyzed cross-sectionally to assess factors associated with prevalent hypertension (N=70,100). Kappa statistics were used to compare self-reported hypertension with provider diagnosed hypertension and prescription antihypertensive medication dispensed (N=41,129).Results: The 3-year incidence of hypertension was 6.9%. After adjusting for demographic and lifestyle characteristics, deployers without combat exposure were less likely to develop new-onset hypertension compared to nondeployers (odds ratio [OR]=0.74; 95% confidence interval [CI]: 0.64, 0.85). There was no association between deployment with combat exposure and hypertension compared to nondeployers (OR=0.94; 95% CI: 0.82, 1.07). Among deployers reporting combat exposures, the risk for incident hypertension was 1.31 (95% CI: 1.07, 1.61) compared to deployers not reporting combat exposures. The prevalence of self-reported hypertension at baseline among Cohort members was 10.4%. There was moderate agreement between self-reported hypertension and provider-diagnosed hypertension, as well as antihypertensive medications dispensed.Conclusion: Military service members are adversely affected by hypertension. Although deployers had lower incidence of hypertension compared to nondeployers, individuals reporting combat exposures were more likely to report new-onset hypertension. Self-reported hypertension had moderate reliability compared with provider-diagnosed hypertension and dispensed antihypertensive medication.
97

Prevalence and Clinical Characteristics of Teeth Extracted with a Diagnosis of Cracked Tooth: A Retrospective Study

Sturgill, Riley B 01 January 2017 (has links)
The body of knowledge that exists regarding cracked teeth is limited. The purpose of this study was to determine the prevalence of cracks among extracted teeth. This retrospective longitudinal cohort study included patients of the Virginia Commonwealth University School of Dentistry that underwent extraction procedures over a 6 year period. The sample consisted of 20,408 patients and 40,870 teeth. Statistical analysis software was used to identify diagnoses of a crack, fracture, or split tooth prior to extraction of the tooth by analyzing the Electronic Health Record (EHR) (axiUm™, Version 6.03.03.1035, Exan Corporation, Vancouver, BC, Canada). There were 3,228 teeth identified as cracked in the 40,870 extracted teeth—an overall prevalence of 7.90%. The percentage of cracked teeth were compared using a chi-square test of homogeneity. The prevalence of cracked teeth varied according to tooth type (chi-square = 95.5, df = 7, p < .0001). Tukey’s multiple-comparison procedure identified the groups of tooth types with a significantly different cracked prevalence. The mandibular 2nd molar had the highest prevalence (9.72%). Age and gender were also significantly correlated with cracked teeth.
98

Prevalencia de Fasciola hepatica en Bovinos beneficiados en el Centro de Faenamiento FRILISAC entre los años 2012-2015

Cordero Calderón, Karem Fiorella January 2016 (has links)
La distomatosis bovina es una enfermedad que afecta enormemente a la ganadería a nivel nacional, no solo por la enfermedad en sí; si no también por las grandes pérdidas económicas que ocasiona y además por ser un problema en salud pública. Es causada por el tremátodo Fasciola hepatica y necesita del caracol del género Lymnaea para que se desarrolle su ciclo biológico. Este estudio tiene como objetivo determinar la prevalencia de Fasciola hepatica en bovinos beneficiados en el Centro de Faenamiento FRILISAC entre los años 2012 al 2015. Se evaluaron 48 Registros mensuales regionales de animales para beneficio según especie, sexo y procedencia del SENASA y 48 Consolidados mensuales de animales beneficiados y peso de carcasa según especie y sexo del SENASA pertenecientes al periodo de tiempo comprendido entre el mes de enero del 2012 hasta diciembre del 2015, de los cuales solamente se utilizó la información correspondiente a los bovinos y su procedencia; se almacenó por cada mes en una base de datos del programa Microsoft Office Excel y se analizó con tablas de frecuencias estadísticas. Los resultados demostraron que se benefició un total de 267 408 bovinos de los cuales 7 680 resultaron positivos a Fasciola hepatica, dando una prevalencia de 2.87%, en donde septiembre registra la mayor prevalencia con 5.29% (1219/23025) y de Junín registra la mayor prevalencia con 4.47% (830/18551). Además, se determinó que existió U$S 128 906.19 en pérdidas económicas directas producidas por el decomiso de hígados de bovinos parasitados con Fasciola hepatica.Bovine flukes is a disease that greatly affects livestock nationwide, not only by the disease itself; but also by large economic losses and also for being a public health problem. It is caused by the trematode Fasciola liver and needs snail Lymnaea gender to their biological cycle develops. This study aims was determine the prevalence of Fasciola hepatica in cattle slaughtered at the Center for Slaughtering FRILISAC between 2012 to 2015. Forty eight regional monthly records for the benefit animals were evaluated according to species, sex and origin of SENASA and 48 monthly Consolidated benefit animal and carcass weight per species and sex of SENASA belonging to the period between January 2012 to December 2015, of which only the share of cattle information and the source is used; It was stored for each month in a database of Microsoft Office Excel program and analyzed with statistical frequency tables. The results showed that a total of 267,408 cattle benefited 7,680 were positive to Fasciola hepatica, giving a prevalence of 2.87%, where in september recorded the highest prevalence with 5.29% (1219/23025) and Junín records higher prevalence with 4.47% (830/18551). In addition, it decided that there was U $ S 128 906.19 in direct economic losses caused by the seizure of parasitized livers of cattle with hepatic Fasciola.
99

Comments on Hynes et al. Prevalence of Marijuana Use among University Students in Bolivia, Colombia, Ecuador and Peru.

Martinez Novack, Maria Claudia, Ortiz Ortiz, Maria Teresa, Castañeda-Carbajal, Bruno, Alvarado, German F. 13 October 2015 (has links)
We have read and analyzed the article entitled “Prevalence of marijuana use among university students in Bolivia, Colombia, Ecuador and Peru”. We propose some objective points which could enhance the internal validity of the study (i.e., we suggest to report participation proportions).
100

The Prevalence of Intrapulpal Cracks in 1st and 2nd Mandibular Molars Requiring Non-Surgical Root Canal Treatment

Lawson, Sean 23 April 2014 (has links)
Few studies have reported the incidence or prevalence of cracked teeth with pulpal involvement. No attempts have been made to evaluate the prevalence or clinical predictors for intrapulpal cracks. The purpose of this study was to investigate the prevalence of intrapulpal cracks in first and second mandibular molars and to determine if clinical findings are predictive for the existence of intrapulpal cracks. First and second mandibular molars (190) requiring non-surgical root canal treatment at the VCU Graduate Endodontic Practice between February 15, 2013 and August 15, 2013 were analyzed retrospectively. Teeth were transilluminated, stained, and inspected for intrapulpal cracks using a dental microscope. Data gathered included: demographics, subjective and objective information regarding the chief complaint to include bite stick test, transillumination, probing depths greater than 4mm, existing restorations, and diagnosis. Chi-square and logistic regression were performed (p<0.05). The prevalence of intrapulpal cracks in first and second mandibular molars combined was 9% (17/190, 95%CI= 5.7% to 13.9%). The prevalence was 7% for 1st molars and 13% for 2nd molars. There was no statically significant difference in the prevalence between first and second mandibular molars. Individual characteristics predictive for the existence of intrapulpal cracks were age, probing depth greater than 4mm, transillumination and a positive Tooth Slooth™ test (all p<0.05). Staining of the pulp chamber after access identified only one of 17 intrapulpal cracks. Staining of the pulp chamber did not significantly increase the ability to identify intrapulpal cracks. Neither diagnosis, sex, nor existing restorations were significant predictors for intrapulpal cracks. Probing depth greater than 4mm, age over 40 and a positive Tooth Slooth™ test were conjointly significant for predicting intrapulpal cracks.

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