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Genetically modified food and crops : perceptions of risksHall, Clare R. January 2010 (has links)
The debate around genetically modified food and crops has proved to be complex and far-reaching, involving diverse stakeholder groups and many issues. Although the extent of global uptake of GM crops has been substantial (23 countries and 114.65 million hectares by 2007), it is significant that four countries are responsible for 86% of all GM plantings, and that a number of key food markets (for example the EU and Japan) remain largely "GM-free‟. This suggests that there is reluctance on the part of many countries to embrace GM technology. There are likely many reasons for this, but one significant issue is that of the perception of the risks associated with the technology. There is a distinction between risk that exists in the world and that can be measured (objective risk) and risk that is perceived by an individual to exist and that is constructed by them based on their values and preferences. When technical measurement of actual risks is not possible, peoples‟ own perceptions of risks become important. This thesis aims to investigate the topic of risk perceptions associated with GM food and crops. Different stakeholder groups have been targeted, and a range of methodologies from a variety of disciplines have been employed to investigate what factors can be shown to influence risk perception. A range of factors were identified from existing literature, as having potential impact on risk perceptions. A number of these were investigated, some of which were found to have some influence on levels of risk perception. Results demonstrate that factors influencing peoples‟ perceptions of risk relating to GM food and crops, include the uncertainty associated with the technology, and trust in regulators, policy makers and others with control over the future development of the technology. Other factors found to be important to levels of risk perception held by different stakeholder groups, were a range of socio-demographic and cultural variables, the relationship between perceived risks and benefits, the equity of impacts, and the influence of third parties. There are a number of implications for the development of the GM debate arising from the findings. First, as there are socio-demographic and cultural factors linked to the perceptions of risk associated with GM technologies in food and agriculture, it is important to recognise that different people will react differently to the technology. Specifically, results from this thesis show that it may be that men, those who are more highly educated, those with a less ecocentric worldview, and those living in urban areas, are likely to respond more favourably to targeted promotional campaigns. As regards the farming community, results show that the first farming adopters are likely to be those who are both owners and tenants, not in an urban fringe location, potato growers, and not barley growers. Second, this thesis provides evidence that third parties are particularly important to farmers, thus it is crucial to recognise that there is potentially a long chain of action and reaction amongst many different stakeholders and actors impacting on farmers' levels of risk perception, and hence willingness to adopt the technology. Third, results from this research demonstrate that the linked issues of the relationship between risks and benefits, and the equity of (positive and negative) impacts, require that all stakeholders are content that they will receive a share of the benefits (if any) to be derived from the technology, and that neither they nor any other group of stakeholders are unduly impacted by the risks or negative impacts (if any) of the technology. Important here is the recognition that perceptions are as important as actual impacts. Fourth, the issue of trust has been shown by the results obtained by this research to be extremely important to peoples' perceptions of risk. It can be concluded that trust is of wider social and political importance that relates to the need to ensure greater democratisation of decision-making in order to re-establish trust in authorities. In the case of GM food this may require a rethinking of the EU legislation relating to the technology. This also relates to point below about the delivery of messages and education. Information sources must be trusted by those at whom the messages are aimed. More importantly though, if people are to trust decision making processes, there needs to be stakeholder involvement at an early stage of decision making, that allows some impact on decisions taken. In the case of the GM debate it may indeed be too late as decisions about the technology, its applications, the regulatory processes and its inclusion within the food chain are well established. Perhaps the best that can be hoped for is that lessons will be learnt and applied to future technology developments of relevance to the food chain, such as, nano-technology. Finally, this thesis has shown that uncertainty is central to peoples' perceptions of risk. This could be addressed through a combination of additional research into what is uncertain to people, the impacts and implications of the technology, more effective dissemination of existing knowledge, and impartially delivered messages and education strategies from trusted sources that address the concerns that people have about the technology. Importantly however there must be an acknowledgement that uncertainty is not restricted to "knowledge deficit‟ but encompasses the scientific uncertainties inherent within the technology, and is framed by the social and cultural values of those whose views are considered. This thesis uniquely targeted diverse groups and employed a combination of different methods from a variety of disciplines. By doing this the study has increased understanding of the views of two groups (campaigners and farmers) who are crucial to the uptake of the technology, and who are seldom researched in the area of attitudes to GM technologies. The diversity of groups, methods and disciplines brought together in this thesis is important because the issue of GM has proved to be complex and far-reaching, and previous discussions of risk perceptions have been complex and disjointed. All groups investigated here are stakeholders in the process, and as such their views and concerns relating to risk perceptions of GM technologies ought to be taken into consideration.
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Níveis de elementos-traço em organismos marinhos utilizados para consumo humano / Levels of trace elements in marine organisms used for human consumptionCardoso, Marcia de Oliveira 15 June 2018 (has links)
O consumo de peixes e frutos do mar está associado à manutenção de uma dieta saudável em função da sua proteína de elevado valor biológico, da presença de ácidos graxos poli-insaturados e de importantes nutrientes como selênio, ferro, cálcio e fósforo. No entanto, esses organismos representam uma importante fonte de elementos-traço contaminantes para os seres humanos em função da bioacumulação desses elementos que também podem biomagnificar ao longo da cadeia alimentar. Apesar da ocorrência natural de elementos-traço no meio ambiente, sua concentração nos ecossistemas costeiros tem aumentado drasticamente em função de atividades antropogênicas, fazendo com que os organismos marinhos atuem como um elo da contaminação ambiental à contaminação humana. O presente trabalho avalia a concentração de elementos-traço em diferentes tecidos de organismos marinhos sob dois aspectos: (1) o risco alimentar associado ao consumo das espécies analisadas e (2) a bioacumulação dos elementos em diferentes tecidos. Para isso foram analisadas três espécies de peixes comercializadas na cidade de Santos (SP): Sphyraena guachancho (bicuda), Priacanthus arenatus (olho de cão) e Genidens genidens (bagre) e três espécies coletadas em diferentes pontos do Sistema Estuarino de Santos (SP): Callinectes danae (siri azul), Mytella guyanensis (mexilhão) e Mugil curema (parati). O hábito alimentar foi o principal critério para seleção das espécies. O risco alimentar, calculado pelo Índice Provisório de Risco (PHI) e pelo Índice Provisório de Risco Total (PTHI), apresentou valores elevados para Sphyraena guachancho (espécie piscívora) e para peixes e siris coletados no Sistema Estuarino de Santos. A bioacumulação foi associada à espécie, tecido e tipo de elemento avaliado. A espécie piscívora apresentou elevada concentração de Ba, Hg e Ag no tecido muscular, indicando a potencial biomagnificação desses elementos ao longo da cadeia alimentar. Genidens genidens, espécie detritívora, apresentou elevada concentração de Ba, Cd e Pb na nadadeira, possivelmente associado às estratégias de detoxificação da espécie, por meio da imobilização desses contaminantes no esporão ósseo. / The consumption of fish and seafood is associated with the maintenance of a healthy diet due to its protein of high biological value, the presence of polyunsaturated fatty acids and important nutrients as selenium, iron, calcium and phosphorus. However, these organisms represent an important source of contaminant trace elements for humans due to the bioaccumulation of these elements in tissues that can also biomagnify along the food chain. Despite the natural occurrence of trace elements in the environment, its concentration in coastal ecosystems has increased dramatically as a result of anthropogenic activities, causing marine organisms to act as a link between environmental and human contamination. The present work evaluates the concentration of trace elements in different tissues of marine organisms under two aspects: (1) the food risk associated with the consumption of the species analyzed and (2) the bioaccumulation of the elements in different tissues. Three species of fish commercialized in the city of Santos (SP) were analyzed: Sphyraena guachancho (bicuda), Priacanthus arenatus (dog eye) and Genidens genidens (catfish) and three species collected at different points of the Santos Estuarine System (SP): Callinectes danae (blue crab), Mytella guyanensis (mussel) and Mugil curema (parati). The eating habit was the main criteria for selection of the species. The food risk, calculated by means of the Provisional Hazard Index (PHI) and the Provisional Total Hazard Index (PTHI), presented high values for the piscivorous species Sphyraena guachancho and for fish and crabs collected in Santos Estuarine System. The bioaccumulation was associated with the species, tissue and type of element evaluated. The piscivorous species had a high concentration of Ba, Hg and Ag in muscle tissue, indicating the potential biomagnification of these elements along the food chain. Genidens genidens, a detivorous species, presented a high concentration of Ba, Cd and Pb in the fin, possibly associated with the detoxification strategies of the species, through the immobilization of these contaminants in the bone spur.
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Environmental determinants associated with Type 1 diabetes-related autoantibodies in children /Wahlberg, Jeanette, January 2005 (has links) (PDF)
Diss. (sammanfattning) Linköping : Linköpings universitet, 2005. / Härtill 5 uppsatser.
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Níveis de elementos-traço em organismos marinhos utilizados para consumo humano / Levels of trace elements in marine organisms used for human consumptionMarcia de Oliveira Cardoso 15 June 2018 (has links)
O consumo de peixes e frutos do mar está associado à manutenção de uma dieta saudável em função da sua proteína de elevado valor biológico, da presença de ácidos graxos poli-insaturados e de importantes nutrientes como selênio, ferro, cálcio e fósforo. No entanto, esses organismos representam uma importante fonte de elementos-traço contaminantes para os seres humanos em função da bioacumulação desses elementos que também podem biomagnificar ao longo da cadeia alimentar. Apesar da ocorrência natural de elementos-traço no meio ambiente, sua concentração nos ecossistemas costeiros tem aumentado drasticamente em função de atividades antropogênicas, fazendo com que os organismos marinhos atuem como um elo da contaminação ambiental à contaminação humana. O presente trabalho avalia a concentração de elementos-traço em diferentes tecidos de organismos marinhos sob dois aspectos: (1) o risco alimentar associado ao consumo das espécies analisadas e (2) a bioacumulação dos elementos em diferentes tecidos. Para isso foram analisadas três espécies de peixes comercializadas na cidade de Santos (SP): Sphyraena guachancho (bicuda), Priacanthus arenatus (olho de cão) e Genidens genidens (bagre) e três espécies coletadas em diferentes pontos do Sistema Estuarino de Santos (SP): Callinectes danae (siri azul), Mytella guyanensis (mexilhão) e Mugil curema (parati). O hábito alimentar foi o principal critério para seleção das espécies. O risco alimentar, calculado pelo Índice Provisório de Risco (PHI) e pelo Índice Provisório de Risco Total (PTHI), apresentou valores elevados para Sphyraena guachancho (espécie piscívora) e para peixes e siris coletados no Sistema Estuarino de Santos. A bioacumulação foi associada à espécie, tecido e tipo de elemento avaliado. A espécie piscívora apresentou elevada concentração de Ba, Hg e Ag no tecido muscular, indicando a potencial biomagnificação desses elementos ao longo da cadeia alimentar. Genidens genidens, espécie detritívora, apresentou elevada concentração de Ba, Cd e Pb na nadadeira, possivelmente associado às estratégias de detoxificação da espécie, por meio da imobilização desses contaminantes no esporão ósseo. / The consumption of fish and seafood is associated with the maintenance of a healthy diet due to its protein of high biological value, the presence of polyunsaturated fatty acids and important nutrients as selenium, iron, calcium and phosphorus. However, these organisms represent an important source of contaminant trace elements for humans due to the bioaccumulation of these elements in tissues that can also biomagnify along the food chain. Despite the natural occurrence of trace elements in the environment, its concentration in coastal ecosystems has increased dramatically as a result of anthropogenic activities, causing marine organisms to act as a link between environmental and human contamination. The present work evaluates the concentration of trace elements in different tissues of marine organisms under two aspects: (1) the food risk associated with the consumption of the species analyzed and (2) the bioaccumulation of the elements in different tissues. Three species of fish commercialized in the city of Santos (SP) were analyzed: Sphyraena guachancho (bicuda), Priacanthus arenatus (dog eye) and Genidens genidens (catfish) and three species collected at different points of the Santos Estuarine System (SP): Callinectes danae (blue crab), Mytella guyanensis (mussel) and Mugil curema (parati). The eating habit was the main criteria for selection of the species. The food risk, calculated by means of the Provisional Hazard Index (PHI) and the Provisional Total Hazard Index (PTHI), presented high values for the piscivorous species Sphyraena guachancho and for fish and crabs collected in Santos Estuarine System. The bioaccumulation was associated with the species, tissue and type of element evaluated. The piscivorous species had a high concentration of Ba, Hg and Ag in muscle tissue, indicating the potential biomagnification of these elements along the food chain. Genidens genidens, a detivorous species, presented a high concentration of Ba, Cd and Pb in the fin, possibly associated with the detoxification strategies of the species, through the immobilization of these contaminants in the bone spur.
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Využití umělé inteligence pro snižování rizika v podniku / The Use of Artificial Intelligence to Reduce the Risk in the FirmSamohýl, Lukáš January 2016 (has links)
This diploma thesis is focused on risk analysis of dry dog food range of products sold in a retail chain named Zvěrokruh. The main goal of this work is creation of model with use of the fuzzy logic. The model helps with the dry dog food range risk evaluation. The model is created in MS Excel and MATLAB. Outcome of this work is a tool which evaluate quality of the dry dog food, which can be afterwards analysed in other point of view.
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Egenkontroll i livsmedelsbranschen utifrån verksamheternas perspektiv : en kvalitativ studie / Self-monitoring in the food business based on the business perspective : a qualitative studyJönsson, Gustav, Lindhé, Hanna January 2014 (has links)
Verksamhetsutövare inom livsmedelsbranschen har ett ansvarar för att den mat som producerats är säker. År 2009 gjordes ändringar i den svenska livsmedelslagen där bland annat kraven försvann på att verksamhetsutövare måste ha skriftliga rutiner och dokumentation (Lindblad, Westöö, Lindqvist, Hjertqvist & Andersson, 2009). Oavsett om verksamhetsutövarna har skriftliga rutiner och dokumentation eller inte måste de kunna bevisa att de har tillräcklig kunskap för att arbeta med livsmedelshantering. Genom ett fungerande system för egenkontroll, alltså en egen kontroll av verksamheten, skapas säkra livsmedel och risken för matförgiftning minskar (Israelsson, 2006). Syftet med denna studie är att undersöka verksamhetsutövarna inom livsmedelsbranschens uppfattning om egenkontroll. Denna studie bygger på kvalitativa semi-strukturerade intervjuer med sex stycken verksamhetsutövare inom livsmedelsbranschen och en livsmedelsinspektör. Urvalet av respondenter till studien begränsades till en kommun i södra Sverige. Samtliga intervjuer spelades in och transkriberades sedan ordagrant för analysering. Respondenterna i studien såg positivt på förändringen i dagens lagstiftning, men många hade ändå valt att ha kvar sina gamla egenkontrollprogram. De såg det som en säkerhet och trygghet i att kunna gå tillbaka till den och luta sig mot de rutiner som fanns nedskrivna. / Food businesses are responsible to ensure that the food they produce is safe. In 2009 changes were made to the Swedish laws on food safety, with one of the resulting changes being that the previous requirements of having written procedures and documentation disappeared (Lindblad, Westöö, Lindqvist, Hjertqvist & Andersson, 2009). However, whether a business has written procedures and documentation or not, it must still be able to prove that it and its employees have enough knowledge to safely work with food. Through a functioning system of self-monitoring, the risk of food poisoning decreases (Israelsson, 2006). The aim of this study is to investigate the food business' opinion regarding the self-monitoring system. This study is based on qualitative semi-structured interviews with six operators within the food business as well as one food inspector. The respondents to the study were geographically limited to southern Sweden. All the interviews were recorded and transcribed verbatim for analysis. The respondents in this study were positive to the change in current law, but many still chosen to retain their old self-monitoring system. They saw it as a safety measure as well as being beneficial when it comes to going back and look at the documented routines.
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Evaluation probabiliste du risque lié à l'exposition à des aflatoxines et des fumonisines dû à la consommation de tortillas de maïs à la ville de Veracruz / Evaluación probabilistica de riesgo por exposición a aflatoxinas y fumonisinas por consumo de tortillas en la ciudad de Veracruz / Probabilistic risk assessment for aflatoxins and fumonisins exposition through the consumption of maize tortillas in Veracruz City, MexicoWall Martinez, Hiram Alejandro 20 October 2016 (has links)
Un des dangers chimiques les plus importants relevés par l'OMS concerne la contamination des céréales par les mycotoxines et notamment les aflatoxines et les fumonisines. La réglementation recommande des contaminations maximales d'aflatoxines dans les céréales inférieures à 20 mg/kg ; cependant on relève couramment des taux supérieurs à 200 mg/kg dans le maïs au Mexique. Bien qu'il ait été évalué que le processus de nixtamalisation détruit plus de 90 % des fumonisines et de 80 à 95 % des aflatoxines, le taux résiduel peut encore être élevé : certaines publications rapportent des concentrations jusqu'à 100 mg/kg dans les tortillas, ce qui représente un risque avéré vue la grande consommation de tortillas au Mexique (325g/j). Le JECFA (2001) a établi une dose maximale acceptable de 2μg/kg pc/j pour la fumonisine et recommande de réduire l'exposition aux aflatoxines au plus faible niveau possible en considérant que le seuil de 1 ng/kg pc/j ne devrait pas être atteint. Au cours de cette thèse 3 enquêtes aléatoires et représentatives ont été menées dans 40 tortillerias de la ville de Veracruz. La consommation de maïs de la population a été évaluée à partir d'un questionnaire de consommation. L'analyse des mycotoxines a été réalisée par HPLC-FD par utilisation de colonnes à immunoaffinité selon la réglementation européenne (CIRAD-Montpellier). L'analyse des données obtenues a été effectuée selon une méthode probabiliste permettant de construire une fonction de distribution de probabilités à partir de la méthode de Monte Carlo (UBO). La représentativité de la population a été validée à partir d'évaluation de quotas de population après échantillonnage aléatoire initial. La contamination des tortillas a été mesurée à 0.54-1.96 mg/kg pour les aflatoxines et à 65-136 mg/kg pour les fumonisines. La consommation moyenne de tortillas a été mesurée à 148 g de maïs par jour. L'exposition de la population aux aflatoxines apparaît alors comprise entre 0,94 et 3,14 ng/kg pc/j et celle aux fumonisines entre 146 et 315 ng/kg pc/j. Les échantillons les plus contaminés proviennent des tortillerias réalisant elles-mêmes leur procédure de nixtamalisation. L'analyse des résultats montre que 60 % de la population de Veracruz serait à risque selon les préconisations du JECFA. L'exposition aux fumonisines atteint 5 % de la dose maximale acceptable, du fait d'une relativement faible contamination du maïs à cette mycotoxine. Les résultats montrent donc un risque sanitaire pour la population de la ville de Veracruz. Une extension de ce travail à la totalité de l’Etat de Veracruz, incluant la population rurale, devrait être menée du fait du risque probablement accru de cette dernière catégorie de population en lien avec sa plus forte consommation de maïs. / One of the chemical hazards that WHO has reported more frequently is cereals contamination with mycotoxins, mainly aflatoxins and fumonisins. NOM-188-SSA1-2002 establishes that aflatoxin concentration in grain should not exceed 20 mg kg-1 ; however, there are reported concentrations > 200 mg kg-1 in maize. Although it has been documented that nixtamalizacion removes more than 90% of fumonisins and between 80 and 95% of aflatoxins, the residual amount could be important, finding reports concentrations higher than 100 mg kg-1 of aflatoxin in tortilla, representing a risk due to the high consumption of tortillas in Mexico (325 g d-1). The JECFA (2001) establishes a maximum intake of 2 mg kg-1 pc d-1 for fumonisin and aflatoxin recommends reducing “as low as reasonably achievable” levels. 3 random and representative sampling in Veracruz city, each in 40 tortillerias, were made. Corn intake and weight of the population were estimated using a consumption questionnaire. Mycotoxins analysis were performed by HPLC-FD using immunoaffinity columns according to European standard UNE-EN ISO 14123 : 2008 for aflatoxins and UNE-EN 13585 : 2002 for fumonisin in the CIRAD (Montpellier, France). Statistical analysis were performed under a probabilistic approach in collaboration with the University of Bretagne Occidentale (Brest, France), building probability density function (PDF) and using the Monte Carlo method. PDF parameters of the weight of the population was 74.15kg for men (which coincides with reported by CANAIVE) and 65.83kg for women ; the pollution aflatoxin tortilla was 0.54 – 1.96mg kg-1 and fumonisin from 65.46 – 136.00mg kg-1 ; the tortilla consumption was 148.3g of corn per person per day ; the daily intake of aflatoxins was 0.94 – 3.14ng kg-1 bw d-1 and fumonisin of 146.24 – 314.99ng kg-1 bw d-1. Samples with higher aflatoxin contamination came from tortillerias that make the nixtamalization in situ. In assessing exposure it was found that up to 60% of the population could be consuming more than the recommended by JECFA (2001) for aflatoxin dose (1ng kg-1 bw d-1). Exposure to fumonisins intake was < 5% due to low contamination by these mycotoxins. The results suggest that the population of the city of Veracruz could be in food risk by eating contaminated corn tortillas AFT. It is advisable to extend this study in rural communities, where risk factors could increase.
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Analyse d'incertitude en situation accidentelle : transfert de radionucléides dans l'environnement et évaluation de l'exposition humaine par voie alimentaire / Uncertainty analysis in accidental situation : environmental transfer of radionuclides and assessment of the human food exposure pathwaySy, Mouhamadou Moustapha 21 March 2016 (has links)
L’évaluation des risques, en situation d’urgence nucléaire, est entachée d’incertitudes sur le transfert de substances radioactives dans les écosystèmes terrestres et vers l’homme à travers la chaîne alimentaire pouvant altérer les décisions. L’ampleur des répercutions des accidents de Tchernobyl et de Fukushima a mis en évidence la difficulté de gérer les conséquences post-accidentelles de tels événements et d’appréhender les incertitudes dans les prises de décision. L’objectif de cette thèse est de développer une méthodologie pour la prise en compte des incertitudes dans les modèles d’évaluation de risque environnemental et alimentaire afin d’améliorer les outils d’aide à la décision en situation accidentelle. Différents modèles bayésiens hiérarchiques visant à saisir, dans un cadre unique de modélisation, l’incertitude et la variabilité sur des paramètres radioécologiques d’intérêt en situation post-accidentelle ont été développés. Les paramètres de ces modèles ont été estimés par inférence bayésienne sur des données collectées à partir d’une revue étendue de la littérature. L’influence sur les modèles d’évaluation de risque, des incertitudes autour de ces paramètres radioécologiques, a été évaluée par simulations probabilistes et analyses de sensibilité, appliquées à deux cas d’études : un accident hypothétique et l’accident de Fukushima. Les travaux réalisés dans cette thèse contribuent à améliorer la connaissance autour des processus clés de transfert de radionucléides dans l’environnement et la paramétrisation des modèles radioécologiques d’évaluation de risque en ligne avec les axes de recherche prioritaires définis par la communauté scientifique en radioécologie. / Risk assessment, in case of nuclear emergency, is confronted to uncertainties on the transfer of radioactive substances in terrestrial ecosystems and to human population through the food chain, which could affect the reliability of decisions. The extent of the repercussions of Chernobyl and Fukushima accidents highlighted the difficulty of managing the consequences of such disasters and specifically to accommodate the different sources of uncertainty within decision-making processes. The objective of this research is to develop a methodology to account for uncertainties within environmental and food risk assessment models to improve decision support tools used for accidental situations. Different hierarchical Bayesian models aiming at capturing, within a unique modelling framework, uncertainty and variability about radioecological parameters of great importance for accidental situation were developed. Models parameters were estimated by Bayesian inference applied on databases obtained by an extended literature review. The impact on the risk assessment models of uncertainties about these radioecological parameters was then assessed by stochastic simulations and sensitivity analyses applied on two case-studies: a hypothetical accident simulating a standardized deposition of radionuclides and the accident of Fukushima nuclear power plant. The works developed in this project contribute to enhance knowledge on key processes governing environmental transfer of radionuclides and to improve the parameterization of the radioecological risk assessment models with respect to the research lines outlined by the scientific community in radioecology.
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Mykotoxine und Kindergesundheit / Elterliche Risikowahrnehmung und neue Ansätze für das Risikomanagement / Mycotoxins and child health / Parental risk perception and new risk management optionsNiens, Christine 05 July 2013 (has links)
No description available.
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Méthodes de Monte Carlo du second ordre et d’inférence bayésienne pour l’évaluation des risques microbiologiques et des bénéfices nutritionnels dans la transformation des légumes / Second order Monte Carlo and Bayesian inference methods for assessing microbiological risks and nutritional benefits in transformation of vegetableRigaux, Clémence 14 February 2013 (has links)
L'objectif du travail est de mettre en place des méthodes d'évaluation des risques microbiologiques et des bénéfices nutritionnels lors de la transformation des légumes, en vue d'une analyse risque-bénéfice. Le risque (industriel) considéré est l'altération des conserves de haricots verts due à la bactérie thermophile Geobacillus stearothermophilus, et le bénéfice nutritionnel est la teneur en vitamine C des haricots verts appertisés. Des paramètres de référence ont d'abord été acquis, par une méta-analyse par approche bayésienne pour la partie risque. Les paramètres de résistance thermique D à 121.1°C et pH 7, zT et zpH de G.stearothermophilus ont ainsi été estimés respectivement à 3.3 min, 9.1°C et 4.3 unités pH en moyenne en milieu aqueux. Les modèles risque et bénéfice ont ensuite été analysés par la méthode de simulation de Monte Carlo à deux dimensions, permettant une propagation séparée de la variabilité et de l'incertitude. Les pertes en vitamine C prédites par le modèle entre la matière première et les légumes appertisés sont de 86% en moyenne, et le taux de non-stabilité à 55°C prédit est de 0.5% en moyenne, globalement en accord avec la réalité. Une analyse risque-bénéfice a ensuite visé à optimiser le bénéfice tout en gardant le risque à un niveau acceptable, par exploration de scénarios d'interventions possibles basés sur les résultats d'analyses de sensibilité. Enfin, un modèle d'évaluation des risques dus à la bactérie pathogène Bacillus cereus dans une purée de courgettes a été confronté à des données de contamination dans des produits incubés, par le biais d'une inférence bayésienne. / The aim of this work is to set up microbiological risk and nutritional benefit assessment methods in the transformation of vegetables, in view of a risk-benefit analysis. The considered (industrial) risk is the alteration of green bean cans due to thermophilic bacteria Geobacillus stearothermophilus, and the nutritional benefit is the vitamin C content in appertized green beans. Reference parameters have first been acquired, by a meta-analysis using Bayesian inference for the risk part. Thermal resistance parameters D at 121.1°C and pH 7, zT and zpH of G.stearothermophilus have been respectively estimated at 3.3 min, 9.1°C and 4.3 pH units on average in aqueous media. The risk and benefit models have then been analyzed by a two-dimensional Monte Carlo simulation method, allowing a separated propagation of uncertainty and variability. The vitamin C losses between fresh and appertized green beans predicted by the model are of 86% on average, and the predicted non-stability at 55°C rate is of 0.5% on average, in good accordance with reality. A risk-benefit analysis has then been carried out to optimize benefit while keeping risk at an acceptable level, by exploring possible intervention scenarios based on some sensibility analysis results. Finally, a risk analysis model involving pathogenic bacteria Bacillus cereus in a courgette puree has been confronted to incubated product contamination data, by means of a Bayesian inference.
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