• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 198
  • 52
  • 43
  • 14
  • 14
  • 8
  • 7
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 422
  • 422
  • 77
  • 69
  • 59
  • 58
  • 49
  • 42
  • 41
  • 39
  • 39
  • 35
  • 34
  • 34
  • 29
  • 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.
241

Segurança dos alimentos no setor hoteleiro: caracterização das empresas e avaliação da percepção dos agentes envolvidos - estudo de caso / Food safety in the hosting sector: characterization of the enterprises and perception assessment of people involved - case study

Andrade, Marcel Levy de 03 October 2014 (has links)
O deslocamento dos indivíduos e a maior exposição da população a alimentos destinados ao pronto consumo em serviços de alimentação e vias públicas contribuem para a incidência de Doenças Transmitidas por Alimentos (DTA). Nesse contexto é imprescindível conhecer as estratégias utilizadas em unidades produtoras de refeições vinculadas ao turismo para minimizar os riscos de contaminação dos alimentos. A presente pesquisa teve como objetivos: caracterizar os sistemas de gestão da qualidade e segurança de alimentos, identificar o nível de adequação das condições higiênicosanitárias, caracterizar os recursos humanos e avaliar a percepção de risco dos agentes envolvidos sobre segurança dos alimentos nos serviços de alimentação de meios de hospedagem. A pesquisa foi conduzida em unidades produtoras de refeições de hotéis e pousadas, em região do estado de São Paulo, composta por dois municípios, A e B, considerados estâncias turísticas. Concordaram em participar da pesquisa 19 estabelecimentos da região, sendo 72,3% hotéis e 16,6% pousadas pertencentes ao município A e 85,7% e 35,7% da mesma tipologia do município B. Um roteiro de entrevista foi aplicado aos gestores das unidades para caracterizar as empresas quanto aos aspectos organizacionais, adequação aos atos normativos vigentes, recursos humanos e o Sistema de Gestão da Segurança dos Alimentos. Um questionário foi empregado para avaliação da percepção de risco dos manipuladores (n=108) sobre questões de segurança dos alimentos e os dados obtidos, analisados a partir de uma escala estruturada com valores variando de 1\"nenhum risco\" a 7 \"risco muito alto\". Uma escala de desejabilidade social foi aplicada para reduzir vieses de medição. A avaliação das condições higiênico-sanitárias dos estabelecimentos foi realizada com base nos laudos de inspeção dos setores de vigilância sanitária dos municípios e na classificação proposta pelo órgão fiscalizador competente. Construiu-se os bancos de dados com o emprego de software SPSS, 2013, análises descritivas foram realizadas e testes não paramétricos utilizados para a comparação de médias e correlações ao nível de significância de 5%. Os resultados evidenciaram que embora todas as empresas fossem licenciadas pelos órgãos competentes a adoção de Sistema de Gestão da Segurança dos Alimentos ou iniciativas nesta direção, eram mais frequentes nas empresas de maior porte e capacidade de produção, que também possuíam os gestores mais qualificados e com maior conhecimento sobre o assunto e estratégias para promoção da qualidade. Os resultados insatisfatórios das condições higiênico-sanitárias constatados nas inspeções das empresas menores podem ser justificados pelo inadequado critério de seleção, programa de capacitação e avaliação de desempenho deficiente dos funcionários. Os menores níveis de risco percebidos pelos manipuladores de alimentos sobre aspectos que representam entraves para a segurança do alimento reforçaram a falta de conhecimento e conscientização sobre o assunto. Recomenda-se a atuação mais efetiva da fiscalização sanitária uma vez que a implantação, no mínimo das Boas Práticas, é obrigatória para este segmento e que seja adotada pelas empresas uma política de recursos humanos voltada para atender aos anseios dos funcionários, visando motivá-los para o desenvolvimento de serviços de qualidade, produção de alimentos seguros e minimizar os problemas funcionais enfrentados pelos gestores. / The displacement of individuals and the greater exposure of the population to ready-toeat foods and foods offered at street stands contribute to the incidence of Foodborne Diseases (FBD). In this context, strategies used in food services linked to tourism meals are essential to minimize the risk of food contamination. This study aimed to characterize the systems of quality management and food safety, to identify the adequacy of sanitary conditions, to characterize the human resources and to evaluate the risk perception of people involved in food safety in the hosting sector. The study was conducted in food services of hotels and hostels, São Paulo State, in two municipalities, A and B, considered tourist resorts. Nineteen establishments were investigated in this research, encompassing 72.3% hotels and 16.6% hostels from municipality A, and 85.7% and 35.7% in municipality B. A questionnaire was applied to managers of the businesses to characterize the companies in terms of organizational aspects, compliance to current legislation, human resources and the Management System of Food Safety. One questionnaire was used to evaluate of risk perception of food handlers (n=108) about food safety. For the questionnaire analysis, a scale 1 \"no risk\" and 7 \"very high risk\" was defined. A scale of social desirability was applied to reduce bias of measurements. The hygienic and sanitary conditions of the establishments were evaluated based on inspection reports of health surveillance of municipalities and on the classification proposed by competent sectors. Databases were performed using the SPSS software, 2013, besides descriptive analyses and non-parametric tests were used to compare means and correlations at a significance level of 5%. The results showed that although all companies were licensed by the competent sectors, the adoption of the Food Safety Management System or some initiatives in this direction were more common in large enterprises with greater production capacity. These establishments had the most qualified managers with greater knowledge on the subject, promoting quality strategies. The unsatisfactory sanitary conditions results in the small companies may be justified by the inappropriate selection criteria, lack of training and deficient program to evaluate employee performance. The low levels of risk perception by food handlers regarding aspects that are barriers to food security reinforced the lack of knowledge and awareness on the subject. A more effective action of sanitary inspection is recommended once the implementation of good practices is mandatory for this segment and it is a policy adopted by companies to meet the needs of employees, aiming to motivate them to improve quality and safety of food production and to minimize functional problems faced by business managers.
242

The Decision and Rationale which Led to Construction on High-risk Land after the 1964 Alaska Earthquake: Analysis of Risk-based Cultural Dissociation

Selkregg, Sheila Ann 01 January 1994 (has links)
Many lives and much property are lost in disasters when individuals and communities choose to ignore information which could mitigate the potential disaster. This case study examines community and individual decision processes and rationale which led to construction of a high-occupancy high-rise courthouse on land designated as high risk after the 1964 Alaska earthquake. The study reviews policy and decision making, psychology, and risk management literature to explore the psychological mechanisms and processes of hazard mitigation decisions. It questions why individuals and communities choose not to mitigate when they have the information which makes risk mitigation possible. The hypothesis theorizes risk-based cultural dissociation and submits that individuals and society process risk-related information in a manner that allows for interpretation and acknowledgement of information so that it is compatible with individual and social agendas and constructs. Society and individuals can and do completely deny or dissociate from risk-related information. This exploratory research uses macro, meso, and micro levels of analysis to examine the environmental setting, land ownership and power, and professional and public seismic information. This examination is placed in the context of Anchorage's post-earthquake reconstruction momentum. Indepth interviews with elected officials, a bank president, insurance executives, investors, builders, appointed officials, private and public professionals, court representatives, a judge, a juror, and citizens provide insight into risk perception and individual and community agendas. The interviews revealed each level of analysis had different perceptions of risk and different agendas. Professional warnings not to reconstruct on high-risk land were ignored. Downtown economic interests and powerful individuals significantly impacted the community decision process. One charismatic leader played a major role in the community reconstruction and courthouse decisions. Research findings support the hypothesis. Individuals consistently chose to deny earthquake potential in their daily lives. Selective interpretation of information allowed individuals to support their own agendas. Community decision processes allowed deletion of important information and a transference of responsibility, resulting in no decision body or individual feeling responsible for the decision. Risk-based cultural dissociation is defined and presented in this research as a direction for future study.
243

The Effects Of Exchange Rates, Oil Prices, Global Risk Perceptions And Global Warming On Food Prices

Dagdelen, Derya 01 September 2012 (has links) (PDF)
This thesis examines the relationship between food prices, oil prices, carbon emission prices, exchange rates and global risk perception. To obtain the effects of these variables on the food prices, Toda and Yamamoto procedure is employed for 5-day week daily time series covering the period February 27, 2008 and March 21, 2011. The empirical results indicate that only volatility index Granger causes food prices. Furthermore, according to results of generalized impulse response plots food prices respond to all variables in the short run.
244

Ontario Snowmobile Tourism: Responses to Climate Variability and Change

Gilmour, Stephen Hugh January 2010 (has links)
A suitable climate, varied scenic terrain, and proximity of communities along Ontario’s system of 39,742 km of snowmobile trails have provided for domestic and international snowmobile tourism. Outdoor winter tourism in many parts of the world has been identified to be at risk to changes in global climate. The Intergovernmental Panel on Climate Change in its Fourth Assessment Report (AR4) reported a global increase of temperature of 0.74 degrees Celsius for the period 1906 to 2005 and estimates that by the end of the 21st century the global mean temperature will increase between 1.8 degrees Celsius to 4.0 degrees Celsius. Temperature increases of only a few degrees may contribute to variances in snow-based tourism reliant on the reliability of natural snow cover. This study examines the spatial and temporal impacts of climate change scenarios upon snowmobile season length and operations within the snowmobile industry in the Province of Ontario Canada to six climate change scenarios for the 21st century. Snowmobile trail operations in Ontario are reliant upon a minimum natural snow cover of 15 cm for smooth terrain trails and 30 cm to 60 cm for rough terrain trails, temperatures less than 0 degrees Celsius and, human and financial capital. Three or more consecutive snowmobile seasons with ≤ 28 days have been identified as having serious implications for human and financial capital necessary to develop and maintain the snowmobile trail system. As early as the 2020s, north eastern snowmobile districts are projected to be least vulnerable to changes in climate with the longest snowmobile seasons > 28 days, while south central snowmobile districts are projected to be the most vulnerable to changes in climate with the shortest snowmobile seasons of < 28 days. Snowmobile trail managers identified possible strategies to adapt to a changing climate (2020s to 2080s) including: pre-season preparation of the terrain including early season packing of snow cover, re-location of the most vulnerable snowmobile trails, and strengthening inter-district alliances.
245

Ontario Snowmobile Tourism: Responses to Climate Variability and Change

Gilmour, Stephen Hugh January 2010 (has links)
A suitable climate, varied scenic terrain, and proximity of communities along Ontario’s system of 39,742 km of snowmobile trails have provided for domestic and international snowmobile tourism. Outdoor winter tourism in many parts of the world has been identified to be at risk to changes in global climate. The Intergovernmental Panel on Climate Change in its Fourth Assessment Report (AR4) reported a global increase of temperature of 0.74 degrees Celsius for the period 1906 to 2005 and estimates that by the end of the 21st century the global mean temperature will increase between 1.8 degrees Celsius to 4.0 degrees Celsius. Temperature increases of only a few degrees may contribute to variances in snow-based tourism reliant on the reliability of natural snow cover. This study examines the spatial and temporal impacts of climate change scenarios upon snowmobile season length and operations within the snowmobile industry in the Province of Ontario Canada to six climate change scenarios for the 21st century. Snowmobile trail operations in Ontario are reliant upon a minimum natural snow cover of 15 cm for smooth terrain trails and 30 cm to 60 cm for rough terrain trails, temperatures less than 0 degrees Celsius and, human and financial capital. Three or more consecutive snowmobile seasons with ≤ 28 days have been identified as having serious implications for human and financial capital necessary to develop and maintain the snowmobile trail system. As early as the 2020s, north eastern snowmobile districts are projected to be least vulnerable to changes in climate with the longest snowmobile seasons > 28 days, while south central snowmobile districts are projected to be the most vulnerable to changes in climate with the shortest snowmobile seasons of < 28 days. Snowmobile trail managers identified possible strategies to adapt to a changing climate (2020s to 2080s) including: pre-season preparation of the terrain including early season packing of snow cover, re-location of the most vulnerable snowmobile trails, and strengthening inter-district alliances.
246

Factors influencing individuals' decision-making during high-risk short-notice disasters: the case study of the August 21st, 2011 Goderich, Ontario tornado

Silver, Amber 07 August 2012 (has links)
The hazards literature has identified many factors as being influential in the decision making process during high risk, short-notice disasters. Risk perception and previous disaster experience are commonly identified as two of the more influential factors in this complex process. However, few studies adequately address the complex role(s) that these factors play in self-protective decision-making during successive high-risk events. In particular, the role of previous disaster experience during subsequent events is still a matter of considerable discussion and inconsistent findings. This thesis examines two events that occurred in August, 2011 in Goderich, Ontario: an F-3 tornado that struck the community on August 21st and a tornado warning that was posted for the region three days later on August 24th. This case study provided the opportunity to examine the roles of risk perception and previous disaster experience in the decision-making process during successive high-risk events. Semi-structured interviews (n=35) and close-ended questionnaires (n=268) were conducted to learn about the ways that individuals obtained and understood risk information, and to explore whether and how such information guided protective behaviors during the two events. The interviews were analyzed using thematic coding to identify response patterns, and the questionnaires were analyzed using IBM SPSS software. It was found that a sizable portion of the sample population took protective actions on August 24th in ways that were inconsistent with their actions on August 21st. Also, a significant portion of respondents chose not to take any form of protective action on August 24th despite having previously experienced the damaging tornado. The findings of this research suggest that the significance of previous disaster experience in the decision-making process is highly variable and context-dependent. A second significant research finding involves the impact of the tornado on the place attachments of Goderich residents. It was found that the disaster had significant impacts, both positive and negative, on participants' sense of place. These findings have implications for both short- and long-term disaster recovery.
247

Essays on econometric modeling of subjective perceptions of risks in environment and human health

Nguyen, To Ngoc 15 May 2009 (has links)
A large body of literature studies the issues of the option price and other ex-ante welfare measures under the microeconomic theory to valuate reductions of risks inherent in environment and human health. However, it does not offer a careful discussion of how to estimate risk reduction values using data, especially the modeling and estimating individual perceptions of risks present in the econometric models. The central theme of my dissertation is the approaches taken for the empirical estimation of probabilistic risks under alternative assumptions about individual perceptions of risk involved: the objective probability, the Savage subjective probability, and the subjective distributions of probability. Each of these three types of risk specifications is covered in one of the three essays. The first essay addresses the problem of empirical estimation of individual willingness to pay for recreation access to public land under uncertainty. In this essay I developed an econometric model and applied it to the case of lottery-rationed hunting permits. The empirical result finds that the model correctly predicts the responses of 84% of the respondents in the Maine moose hunting survey. The second essay addresses the estimation of a logit model for individual binary choices that involve heterogeneity in subjective probabilities. For this problem, I introduce the use of the hierarchical Bayes to estimate, among others, the parameters of distribution of subjective probabilities. The Monte Carlo study finds the estimator asymptotically unbiased and efficient. The third essay addresses the problem of modeling perceived mortality risks from arsenic concentrations in drinking water. I estimated a formal model that allows for ambiguity about risk. The empirical findings revealed that perceived risk was positively associated with exposure levels and also related individuating factors, in particular smoking habits and one’s current health status. Further evidence was found that the variance of the perceived risk distribution is non-zero. In all, the three essays contribute methodological approaches and provide empirical examples for developing empirical models and estimating value of risk reductions in environment and human health, given the assumption about the individual’s perceptions of risk, and accordingly, the reasonable specifications of risks involved in the models.
248

Water Scarcity, Climate Change, and Water Quality: Three Economic Essays

Cai, Yongxia 2009 May 1900 (has links)
This dissertation is composed of three essays investigating three aspects of future water issues. The first essay focuses on an examination of water scarcity issues caused by rapid population growth and economic development in Texas. The second essay examines water scarcity under climate change scenarios in Texas. The third essay discusses arsenic-related water quality issues in the drinking water. An integrated economic, hydrological, and environmental model is developed for the first two essays by implicitly incorporating uncertainty about future climate, water demand from all types of water use, a spatial river flow relationship, interaction between ground and surface water, institutional regulations, and the possibilities of inter-basin water transfers (IBTs). In studying water scarcity under economic growth and population growth, we find that while some cities and counties have sufficient water, there are some other cities and counties (especially Dallas, Fort Worth and Austin) facing different degrees of water scarcity problems. In studying the climate change impact, four Global Circulation Models (GCMs) with three Special Report on Emissions Scenarios (SRESs) yield consistent results. Water scarcity becomes even more severe for cities. Texas realizes slight gains in earlier periods and a net loss beginning in 2060. This study finds that twelve IBTs, if there is no climate change, and fourteen IBTs, under the climate change scenario, will be economically feasible in 2060. These IBTs can not only greatly reduce water scarcity, but also create new growth opportunity for Houston. Water is transferred from in-stream flow in source basins. There is no significant impact on other sectors except in-stream flow and water flow out to bay. In the third essay, a two-stage structural model is developed to model household risk-averting behavior with respect to arsenic-related mortality risk in the drinking water. The empirical results suggest that risk perceptions for the parents and children are important in the decision of how much to spend on water treatment, but not in whether or not to treat water. Parents in our sample displayed mixed altruism. The information generated by this dissertation can help state agencies to manage water resources and to improve water-related human health, especially health for children, more effectively and more efficiently.
249

Numeracy, Cancer Risk Perceptions, and Self-Protective Behaviors among U.S. Adults

Malo, Teri 01 January 2011 (has links)
Individuals have become more involved in health-related decisions, in part due to an unprecedented access to information that can be used to enhance both physical and mental health. Much of this health-related information is presented in a numerical format; unfortunately, research suggests many Americans may not possess the literacy skills necessary to comprehend numerical health-related information. More research needs to be conducted to examine numeracy and its role in cancer risk perceptions, and how those risk perceptions relate to cancer self-protective behaviors. The purpose of the current study was to: (a) examine socio-demographic variables associated with numeracy, (b) determine which factors are associated with cancer risk perceptions, and (c) apply the Risk Perception Attitude (RPA) Framework to examine associations between risk perception groups and cancer self-protective behaviors. The study used data from the 2007 Health Information National Trends Survey (HINTS), which was developed by the National Cancer Institute to collect nationally representative data on the U.S. public's use of cancer-related information. Logistic regression was used to assess the association between each dependent variable and independent variables associated with each research question. Results indicated age and education were associated with objective numeracy, whereas age, education, and occupational status were associated with subjective numeracy. Among participants with a previous cancer diagnosis, objective numeracy and smoking status were associated with a somewhat high/very high perceived risk of developing cancer in the future. Age, race/ethnicity, family cancer history, smoking status, and self-reported general health were associated with a somewhat high/very high perceived risk of developing cancer in the future among participants without a previous cancer diagnosis. RPA group was not significantly associated with cancer self-protective behaviors. Findings from this study have important implications for public health, including health communication and interventions designed to enhance health behaviors. Future research should focus on using a full objective numeracy scale with a nationally representative population and examining temporal relationships between cancer risk perceptions and health behaviors.
250

Uncertainty, variability and environmental risk analysis

Filipsson, Monika January 2011 (has links)
The negative effects of hazardous substances and possible measures that can be taken are evaluated in the environmental risk analysis process, consisting of risk assessment, risk communication and risk management. Uncertainty due to lack of knowledge and natural variability are always present in this process. The aim of this thesis is to evaluate some tools as well as discuss the management of uncertainty and variability, as it is necessary to treat them both in a reliable and transparent way to gain regulatory acceptance in decision making. The catalytic effects of various metals on the formation of chlorinated aromatic compounds during the heating of fly ash were investigated (paper I). Copper showed a positive catalytic effect, while cobalt, chromium and vanadium showed a catalytic effect for degradation. Knowledge of the catalytic effects may facilitate the choice and design of combustion processes to decrease emissions, but it also provides valuable information to identify and characterize the hazard. Exposure factors of importance in risk assessment (physiological parameters, time use factors and food consumption) were collected and evaluated (paper II). Interindividual variability was characterized by mean, standard deviation, skewness, kurtosis and multiple percentiles, while uncertainty in these parameters was estimated with confidence intervals. How these statistical parameters can be applied was shown in two exposure assessments (papers III and IV). Probability bounds analysis was used as a probabilistic approach, which enables separate propagation of uncertainty and variability even in cases where the availability of data is limited. In paper III it was determined that the exposure cannot be expected to cause any negative health effects for recreational users of a public bathing place. Paper IV concluded that the uncertainty interval in the estimated exposure increased when accounting for possible changes in climate-sensitive model variables. Risk managers often need to rely on precaution and an increased uncertainty may therefore have implications for risk management decisions. Paper V focuses on risk management and a questionnaire was sent to employees at all Swedish County Administrative Boards working with contaminated land. It was concluded that the gender, age and work experience of the employees, as well as the funding source of the risk assessment, all have an impact on the reviewing of risk assessments. Gender was the most significant factor, and it also affected the perception of knowledge. / Negativa effekter orsakade av skadliga ämnen och möjliga åtgärder bedöms och utvärderas i en miljöriskanalys, som kan delas i riskbedömning, riskkommunikation och riskhantering. Osäkerhet som beror på kunskapsbrist samt naturlig variabilitet finns alltid närvarande i denna process. Syftet med avhandlingen är att utvärdera några tillvägagångssätt samt diskutera hur osäkerhet och variabilitet hanteras då det är nödvändigt att båda hanteras trovärdigt och transparent för att riskbedömningen ska vara användbar för beslutsfattande. Metallers katalytiska effekt på bildning av klorerade aromatiska ämnen under upphettning av flygaska undersöktes (artikel I). Koppar visade en positiv katalytisk effekt medan kobolt, krom och vanadin istället katalyserade nedbrytningen. Kunskap om katalytisk potential för bildning av skadliga ämnen är viktigt vid val och design av förbränningsprocesser för att minska utsläppen, men det är också ett exempel på hur en fara kan identifieras och karaktäriseras. Information om exponeringsfaktorer som är viktiga i riskbedömning (fysiologiska parametrar, tidsanvändning och livsmedelskonsumtion) samlades in och analyserades (artikel II). Interindividuell variabilitet karaktäriserades av medel, standardavvikelse, skevhet, kurtosis (toppighet) och multipla percentiler medan osäkerhet i dessa parametrar skattades med konfidensintervall. Hur dessa statistiska parametrar kan tillämpas i exponeringsbedömningar visas i artikel III och IV. Probability bounds analysis användes som probabilistisk metod, vilket gör det möjligt att separera osäkerhet och variabilitet i bedömningen även när tillgången på data är begränsad. Exponeringsbedömningen i artikel III visade att vid nu rådande föroreningshalter i sediment i en badsjö så medför inte bad någon hälsofara. I artikel IV visades att osäkerhetsintervallet i den skattade exponeringen ökar när hänsyn tas till förändringar i klimatkänsliga modellvariabler. Riskhanterare måste ta hänsyn till försiktighetsprincipen och en ökad osäkerhet kan därmed få konsekvenser för riskhanteringsbesluten. Artikel V fokuserar på riskhantering och en enkät skickades till alla anställda som arbetar med förorenad mark på länsstyrelserna i Sverige. Det konstaterades att anställdas kön, ålder och erfarenhet har en inverkan på granskningsprocessen av riskbedömningar. Kön var den mest signifikanta variabeln, vilken också påverkade perceptionen av kunskap. Skillnader i de anställdas svar kunde också ses beroende på om riskbedömningen finansierades av statliga bidrag eller av en ansvarig verksamhetsutövare.

Page generated in 0.057 seconds