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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.
211

Effects of phosphate type, antimicrobials and processing methods on the quality, shelf-life and sensory characteristics of enhanced catfish fillets

Kin, Sovann 30 April 2011 (has links)
Catfish fillets that were enhanced with salt and various phosphate treatments through vacuum tumbling or multi-needle injection were evaluated for yield, protein exudate (only tumbling), surface color, pH, cooking loss, tenderness, purge loss and shelf-life. An agglomerated sodium phosphate blend (AGSP) was the optimum treatment for both vacuum tumbling and multi-needle injection and was further utilized in conjunction with potassium lactate (PL) and/or potassium acetate (PA) through vacuum tumbling to determine their effect on the quality, shelf-life and sensory characteristics of enhanced catfish fillets. In addition, the combination of AGSP and PA+PL that maximized shelf-life was further utilized in conjunction with liquid or wood smoking to evaluate the quality and inhibition of L. monocytogenes growth in ready-to-eat (RTE) smoked catfish fillets. All phosphate treatments increased (P<0.05) tenderness, but AGSP that contained mono-, tri-, and polyphosphates increased (P<0.05) pH and yield and decreased (P<0.05) yellowness in both tumbling and injection systems when compared to the control treatment. In addition, AGSP decreased (P<0.05) protein exudate when fillets were tumbled and increased (P<0.05) solution pick-up when injected. Psychrotrophic plate counts (PPC) for all phosphate treatments were similar to the control at each storage time and reached 7 log CFU/g by day 7 of storage; however, when AGSP was used in conjunction with PA+PL, PPC and sensory spoilage scores of raw catfish fillets were lower (P<0.05) than the control at each storage time. Marinating with a combination of 0.25% PA and 0.58% PL increased shelf-life (P<0.05) to between 10 and 14 days when compared to the control which had a shelf-life between 7 and 10 days. In addition, consumers preferred (P<0.05) fried catfish fillets that were treated with AGSP with and without PA+PL when compared to non-marinated controls with respect to appearance, flavor and overall acceptability. In conclusion, AGSP optimized yield and improved the quality of refrigerated catfish fillets, and extended shelf-life three days over other treatments when combined with PA+PL. This combined treatment also enhanced sensory properties of fried catfish fillets and had a synergistic effect with wood smoke constituents that inhibited the growth of L. monocytogenes on RTE smoked catfish fillets.
212

Advancing Global Tobacco Control: Exploring Worldwide Youth Attitudes and Behaviors toward Tobacco Use and Control

Veeranki, Sreenivas Phanikumar 01 August 2012 (has links) (PDF)
Tobacco use continues to be the leading cause of preventable death in the world. The disproportionate increase in tobacco use in low- and middle-income countries needs immediate attention. Many smokers begin smoking as adolescents and are most likely to become permanent smokers. Moreover, youth are highly targeted by tobacco industry strategies. However, a gap exists in literature to understand worldwide youth tobacco use and control. The purpose of this study is to 1) identify factors that influence never-smoking youths‟ smoking susceptibility, 2) explore characteristics that influence youth exposure to environmental tobacco smoke (ETS) and 3) to delineate key determinants of youth support for smoke-free policies (SFPs). Data related to worldwide youth tobacco use was obtained from the Global Youth Tobacco Survey for the years 1999-2008. Simple and multiple logistic regression analyses were conducted, after the sample was weighted for design effect, nonresponse patterns and poststratification. Unadjusted and adjusted odds ratios along with 95% confidence intervals were reported. Around 14% of never-smoking youth were susceptible to smoking worldwide. Around 40% and 50% youth were exposed to ETS inside and outside the home respectively, and 78% supported SPFs globally. Parental and peer smoking was strongly associated with smoking susceptibility in never-smoking youth [AOR 2.63, 95% CI 2.43 to 2.84], and youth exposure to ETS inside [AOR 5.09, 95% CI 4.84 to 5.35] and outside [AOR 2.51, 95% CI 2.39 to 2.63] the home, while anti-smoking school education was negatively associated. Youth having knowledge about smoking harm [AOR 2.37, 95% CI 2.22 to 2.54] supported SFPs, while youth exposed to tobacco industry promotion [AOR 0.83, 95% CI 0.78 to 0.89] did not support. The study highlighted a number of modifiable factors that can be used for augmenting global tobacco control in youth. Well-executed anti-smoking campaigns, parental and peer education, inclusion of anti-tobacco education in school curricula, comprehensive SFPs, and comprehensive ban on tobacco industry strategies are important approaches to prevent tobacco use and advance global tobacco control in youth.
213

Respiratory health effects of occupational exposure to bushfire smoke in Western Australia

De Vos, Johanna B. M. January 2008 (has links)
Bushfires are an integral part of the Australian environment, and consequently Australian fire fighters are regularly confronted with the challenge of bushfire fighting activities. Bushfires can be extensive and long-lasting, and as a result fire fighters can be exposed to bushfire smoke for long periods without respite. Anecdotal evidence suggests that bushfire smoke exposure can lead to respiratory symptoms such as coughing, wheezing, and shortness of breath. In an optimal environment, fire fighters are equipped with respirators and protective filters to prevent the inhalation of the air toxics in bushfire smoke. Yet, reports from the fire ground indicate that the protective filters are not effective in preventing the inhalation of bushfire smoke. As a result, fire fighters have increasingly expressed concern about the ineffective equipment and the resultant respiratory symptoms during and after bushfire fighting. This research aims to establish a scientific data base to support the anecdotal evidence. The objectives of the research were: (1) to identify and quantify the air toxics in Western Australian bushfire smoke; (2) to profile the acute respiratory health effects associated with bushfire smoke exposure; (3) to assess the effectiveness of three different types of filters under controlled conditions in a smoke chamber, and in the field during fuel reduction burn-off; (4) to formulate recommendations for reducing fire fighters' exposure to bushfire smoke; and (5) to inform policy decision makers about the most effective form of respiratory protective equipment for bushfire fighting. Exposure trials were conducted in an experimental setting utilising bushfire smoke conditions in a smoke chamber and during prescribed burn-offs. Repeated measurements of respiratory symptoms, pulmonary function and oximetry were undertaken before and after bushfire smoke exposure. In addition, personal air sampling inside the respirators was undertaken to quantify and compare the levels of filtered air toxics. The analysis of the collected data demonstrated that, of those compared, the particulate/organic vapour formaldehyde filter was most effective in protecting fire fighters' respiratory health during the smoke exposure period of maximally 120 minutes. Further research would be useful to determine the v effectiveness of the filters under more realistic conditions during bushfire fighting activities. The findings of this research have resulted in a policy review in Western Australia. In 2006, the Fire and Emergency Services Authority of Western Australia (FESA) reviewed its Bush Fire Smoke Exposure Standard Operational Procedures 51, and now issues the recommended particulate/organic vapour/formaldehyde filters to the 1,000 FESA career fire fighters. The use of protective equipment for bushfire fighters is inadequately regulated worldwide and the recommendation implemented by FESA can be seen as proactive and in advance of national and international best practice. In conclusion, this project was instrumental in the translation of public health research into best practice that protects occupational health, without the need for the lengthy process of legislative reform. Fire fighter organisations in other countries with high frequencies of bushfires could learn from this example, and move to review their policies and introduce adequate personal protection for fire fighters.
214

The effects of physical activity on cigarette cravings

Haasova, Marcela January 2014 (has links)
Rationale: Cigarette cravings are one of the most important clinical phenomena in tobacco addiction. A wide range of studies and research designs may help to increase understanding of the relationship between physical activity (PA) and cigarette cravings. Aims: (i) To investigate the acute effects of walking and isometric exercise on cigarette cravings, withdrawal, and attentional bias among temporarily abstaining smokers. (ii) To quantify the effects of short bouts of PA on cigarette cravings among temporarily abstaining smokers. (iii) To examine who most benefits from PA, whether changes in affect mediate these effects, and whether a specific attribute of PA is associated with cravings. (iv) To investigate whether any association between habitual PA and cravings in smokers could be found. Methods: A randomised controlled crossover trial with three arms addressed aim (i). A systematic review of literature and individual participant data meta-analysis using hierarchical modelling addressed aims (ii) and (iii). Aim (iv) was achieved by using linear regression modelling of cross-sectional data from a smoking cessation study. Results: No difference in cravings, withdrawal, and attentional bias between walking and isometric exercise versus control was found. Bouts of PA decreased cigarette cravings by approximately 30%. Moderate intensity PA provided increased benefit when compared with light intensity, whereas vigorous intensity did not confer additional benefits compared with moderate intensity PA. Also bouts of medium (10 minutes) and longer duration (≥15minutes) appeared to be more effective than short duration (≤ 5 min). No moderators and mediators of this association were identified. Habitual moderate intensity PA was the strongest predictor of cigarette cravings in smokers, MPSS was an additional predictor and alcohol consumption moderated the effects of habitual PA on cravings. Conclusion: Moderate intensity PA could be recommended to smokers to help decrease cigarette cravings.
215

Efeitos do tabagismo e da cessação do tabagismo nos mecanismos de defesa de via aérea, propriedades do muco e inflamação nasal / The effects of smoking and smoking cessation on nasal mucociliary clearance, mucus properties and nasal inflammation

Utiyama, Daniela Mitiyo Odagiri 31 March 2017 (has links)
O tabagismo é um problema mundial de saúde pública e é considerado a principal causa de morte evitável no mundo associado com câncer de pulmão, doença pulmonar obstrutiva crônica e infarto agudo do miocárdio. O tabagismo induz alterações morfológicas e funcionais no sistema respiratório. O transporte mucociliar (TMC) é um dos principais mecanismos de defesa do sistema respiratório que pode ser alterado com a fumaça e outros produtos do cigarro. O objetivo desse estudo foi avaliar os efeitos do tabagismo e da cessação do tabagismo no TMC nasal, nas propriedades do muco e sobre marcadores inflamatórios. Trinta e três indivíduos tabagistas foram incluídos no estudo após concordância com o termo de consentimento livre e esclarecido. O recrutamento de voluntários foi realizado na Faculdade de Medicina da Universidade de São Paulo (FMUSP) e no Ambulatório de Cessação do Tabagismo da Disciplina de Pneumologia do Hospital das Clínicas da FMUSP. As variáveis desfecho foram o TMC nasal analisado por meio do teste de trânsito da sacarina, as propriedades do muco por meio do ângulo de contato e da transportabilidade da tosse por alto fluxo e a quantificação de células inflamatórias e concentração de interleucinas (IL)-6 e IL-8 em lavado nasal. Vinte cessadores (idade média: 51 anos, 9 do sexo masculino) foram avaliados no tempo basal do estudo, 1o mês, 3o mês e 12o mês de cessação do tabagismo e 13 tabagistas (média de idade: 52 anos, 6 do sexo masculino) foram avaliados no tempo basal e 12 meses após o basal. As características demográficas, hábito tabágico inicial e morbidades de tabagistas e de cessadores foram similares. No tempo basal do estudo, os tabagistas e cessadores apresentaram disfunção do TMC nasal (17,9 ± 10,1 min e 17,4 ± 7,7 min, respectivamente, p=0,880). A cessação do tabagismo induziu melhora significativa do TMC nasal no 1o mês, 3º mês e 12o mês em 63%, 76% e 85% dos indivíduos, respectivamente. Somente aos 12 meses, foi possível observar melhora na transportabilidade do muco por alto fluxo (~ 23%), porém com aumento do número de macrófagos (2x) em lavado nasal. Não observamos alterações no ângulo de contato do muco e nas concentrações de citocinas em lavado nasal. Concluímos que a cessação do tabagismo induz melhora rápida no TMC nasal, porém melhora nas propriedades do muco foi observada somente após 12 meses de cessação do tabagismo / Smoking is a health problem in the world. It is considered a main cause of preventable death and is associated with lung cancer, chronic obstructive pulmonary disease and myocardium infarction. Smoking induces morphological and functional changes in the respiratory system. Mucociliary clearance (MCC) is one of the main defense mechanisms of the respiratory system that can be affected by smoke and other cigarette products. The aim of this study was to assess the effects of smoking and smoking cessation on nasal MCC, mucus properties and inflammatory biomarkers. Thirty three smokers were included in this study after agreement with the written informed consent. Subject´s recruitment was performed at Faculdade de Medicina da Universidade de São Paulo (FMUSP) and Ambulatório de Cessação do Tabagismo da Disciplina de Pneumologia do Hospital das Clínicas da FMUSP. The outcome variables were nasal MCC evaluated by saccharin transit test, mucus properties using contact angle and mucus transportability by high airflow and quantification of inflammatory cells number and interleukin (IL)-6 and IL-8 in the nasal lavage fluid. Twenty volunteers in the smoking cessation program (mean age: 51 years, 9 male) were assessed at baseline, month 1, month 3 and month 12 after of the smoking cessation and 13 smokers (mean age: 52 years, 6 male) were assessed at baseline and 12 months after baseline. Demographic characteristics, smoking history and morbidities were similar between the two groups. At baseline, smokers showed impaired nasal MCC (17.9 ± 10.1 min and 17.4 ± 7.7 min, respectively, p=0.880). Smoking cessation significantly improved nasal MCC at 1 month, 3 months and 12 months in 63%, 76% and 85% of the subjects, respectively. Only after 12 months of smoking cessation, improvement in mucus transportability by high airflow (~ 23%) was observed, however, with increased number of macrophages (2-fold) in nasal lavage fluid. No changes were observed in mucus contact angle and cytokines concentrations in nasal lavage fluid. We concluded that smoking cessation induces rapid improvement in nasal MCC, however, improvement in mucus properties were observed only after 12 months of smoking cessation
216

Limitations of Zone Models and CFD Models for Natural Smoke Filling in Large Spaces

Bong, Wen Jiann January 2012 (has links)
This research report examines the use of zone modelling compared with CFD modelling to determine when zone model approximation is valid and when a CFD model might be required. A series of computer simulations with enclosures and fires of various sizes was performed to compare the capabilities and limitations of the two computer methods. The relationship between the size of the enclosure space and the size of the fire has been demonstrated in a dimensionless form. The zone model BRANZFIRE and the CFD model FDS were used for simulating smoke development. The simulations included various full-scale experimental data on both small and large spaces found in the literature. Further simulations of large exemplar spaces with a range of fire sizes were performed to investigate different variables, which have not been examined in full-scale experiments. The simulation results have been compared based on the smoke layer height and the average layer temperature. Zukoski’s smoke filling equation was also used to compare the layer height predictions against BRANZFIRE and FDS. It was found that different data reduction techniques gave different approximations to the layer height. A perfect match between the experimental data and the model output was very difficult to achieve. FDS showed a large uncertainty of the smoke layer height and temperature in the early stages of fire across the enclosure space. In the later stages, this uncertainly became minimised where the smoke layer height and temperature were fairly uniformly developed across the space. For fire enclosures with instantaneous steady-state fires, the predictions between BRANZFIRE and FDS agreed well with each other if the fire size and the enclosure size were within a reasonable range. From the modelling of the full-scale experiments, FDS showed favourable layer-height comparisons against the full-scale experimental tests. However, the output results from BRANZFIRE are less comparable with those of FDS for the experiments with fire growth. An appropriate smoke transport time lag should be included for Zukoski’s smoke filling equation and BRANZFIRE; otherwise, they gave conservative estimates of the layer height to smaller fires with a growth phase. In general, the data reduction methods and zone models should not be used if the fire is too small relative to the enclosure size. A very low temperature rise within the enclosure space would give invalid predictions of the layer height and average layer temperature. This is because there is no clear indication of a separation between the upper and lower smoke layers or temperatures. Single point data of smoke concentrations and temperatures from CFD models should be considered through the entire space or at the specified location of interest. This also applies to an extremely large fire relative to the enclosure size where temperature distribution across the space might not be very homogenous. CFD models could also be used to investigate the details of the smoke properties in the early stages of growing fires, in which the smoke transport lag and the plume effects cannot be seen in BRANZFIRE. This research is intended to provide guidance for fire engineers by determining which of the computer methods can be used confidently and appropriately as a design tool.
217

Exposición al humo ambiental del tabaco y medidas de control del tabaquismo

Martínez Sánchez, José M. 10 December 2010 (has links)
Antecedentes: En España, hasta 3.200 defunciones anuales son atribuidas al tabaquismo pasivo. La exposición al humo ambiental del tabaco (HAT) aumenta el riesgo de padecer enfermedades crónicas como cáncer de pulmón, enfermedades cardiovasculares y enfermedades respiratorias. Hipótesis: 1) Existe una relación entre la exposición al HAT medida mediante cuestionario y la concentración de cotinina en saliva. 2) La exposición al HAT y la concentración de cotinina en saliva es mayor en los trabajadores del sector de la hostelería que en la población general. 3) El aumento de medidas de control del tabaquismo reduce la prevalencia de exposición al HAT. Objetivos: 1) Caracterizar la exposición al HAT en la población general no fumadora mediante un cuestionario y biomarcador antes de la entrada en vigor de la ley 28/2005 de medidas frente al tabaquismo. 2) Comparar la concentración de cotinina en población general y en trabajadores del sector de la hostelería antes de la entrada en vigor de la ley 28/2005 de medidas frente al tabaquismo. 3) Evaluar la correlación entre las medidas de control del tabaquismo y la prevalencia de exposición al HAT en 27 países de la Unión Europea. Metodología: Para conseguir los objetivos marcados se ha realizado un estudio transversal de la población general de Barcelona, un estudio de una cohorte de trabajadores del sector de la hostelería en 5 Comunidades Autónomas antes de la entrada en vigor de la ley (octubre-diciembre 2005) y seguidos durantes 2 años después de la ley (octubre-diciembre 2007) y un estudio ecológico a partir de los datos del Eurobarometro sobre tabaco. Conclusiones: 1) La prevalencia de exposición al HAT entre los no fumadores en España antes de la entrada en vigor de la ley 28/2005 es elevada y tiene una asociación inversamente con la edad. La concentración de cotinina en saliva se asocia con el número de fumadores en casa y la cantidad de cigarrillos fumados en presencia del no fumador. 2) La prevalencia de exposición al HAT y la concentración de cotinina en saliva en España es mayor entre los trabajadores de la hostelería en comparación con la población general antes de la entrada en vigor de la ley 28/2005. 3) El apoyo a la ley 28/2005, la percepción de su cumplimiento y el acuerdo en prohibir definitivamente el consumo de tabaco en todos los lugares públicos, incluidos bares y restaurantes, ha aumentado entre los trabajadores del sector de la hostelería 2 años después de la entrada en vigor de la ley. 4) A nivel ecológico, los países de la Unión Europea con mayor implementación de políticas sanitarias frente al tabaquismo (medidas mediante la escala propuesta por Joossens y Raw) presentan menor prevalencia de consumo de tabaco y menor prevalencia de exposición al HAT en casa y en el trabajo. Además estos países con mayores políticas frente al tabaquismo tienen un mayor apoyo a las medidas de regulación del consumo de tabaco en todos los lugares públicos. / Background: In Spain, up to 3,200 deaths per year were attributable to secondhand smoke (SHS) exposure. SHS has been associated with a variety of health effects among non-smokers, especially lung cancer and ischemic heart disease, and respiratory diseases. Hypotheses: 1) There is a relationship between exposure to SHS measured by questionnaire and cotinine concentration in saliva. 2) Exposure to SHS and salivary cotinine concentration are higher in hospitality workers than in the general population. 3) The increasing of the tobacco control measures reduces the prevalence of exposure to SHS. Objectives: 1) To describe the exposure to SHS in non-smokers from the general population using a questionnaire and salivary cotinine concentration before the Spanish smoking ban. 2) To compare the salivary cotinine concentration between non-smokers from the general population and non-smokers hospitality workers before the Spanish smoking ban. 3) To assess the correlation between tobacco control policies and the prevalence of exposure to SHS in the 27 countries of the European Union. Conclusions: 1) The prevalence of exposure to SHS in general population was high before the Spanish smoking ban and it decreases with the age. Salivary cotinine concentration in the general population depends of the number of smokers and the number of cigarettes smoked in presence of non-smokers at home. 2) The prevalence of exposure and salivary cotinine concentration were higher among non-smoker hospitality workers than in the general population before the Spanish smoking ban. 3) Positive attitudes (in favour) towards smoking ban increased after the ban among hospitality workers. 4) At ecological level, the Tobacco Control Scale scores were strongly associated with a lower prevalence of smokers and a lower self-reported exposure to SHS. Moreover, countries with more tobacco control policies have higher support towards smoking bans in all workplaces (including restaurants, bars, pubs and clubs, and other indoor workplaces).
218

Passive smoking in children : the importance of parents' smoking and use of protective measures /

Johansson, AnnaKarin January 2004 (has links)
Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 6 uppsatser.
219

Role of glutathione in lung's adaptive response against environmental agents that induce oxidative stress /

Kariya, Chirag T. January 2007 (has links)
Thesis (Ph.D. in Toxicology) -- University of Colorado Denver, 2007. / Typescript. Includes bibliographical references (leaves 130-174).
220

Environmental tobacco smoke exposure, respiratory and cardiovascular health in restaurant and bar workers in Mexico.

Barrientos Gutierrez, Tonatiuh. Amick, Benjamin C. Delclos, George L. Gimeno Ruiz de Porras, David Harrist, Ronald B. Hernández-Avila, Mauricio, Kelder, Steven H. Unknown Date (has links)
Source: Dissertation Abstracts International, Volume: 70-07, Section: B, page: 4054. Adviser: Benjamin C. Amick. Includes bibliographical references.

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