Dissertations / Theses: 'Indice de stress'

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Garabedian, Charles. "Développement d’un nouvel indice reflet du bien être fœtal : le Fetal Stress Index." Thesis, Lille 2, 2017. http://www.theses.fr/2017LIL2S022/document.

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La surveillance du bien-être fœtal pendant le travail repose essentiellement sur l’enregistrement du rythme cardiaque fœtal (RCF). Celui-ci, même continu pendant le travail, ne permet pas d’évaluer parfaitement l’oxygénation du fœtus ni le risque d’asphyxie néonatale. En effet, cet outil est imparfait et son évaluation subjective avec une importante variabilité d’interprétation inter et intra opérateur. Des examens dits de seconde ligne sont utilisés en pratique courante pour caractériser l’état fœtal : le prélèvement de sang fœtal au scalp pour l’étude de l’équilibre acido-basique du fœtus (pH ou lactates) ou la pose d’électrode au scalp pour étudier l’ECG fœtal (analyse du segment ST). Ces techniques sont néanmoins invasives et sont soumises à des contraintes techniques. Il y a donc un intérêt à développer des moyens d’évaluation du bien être fœtal à la fois objectifs et non invasifs afin de diminuer la survenue d’une asphyxie périnatale. En effet, celle-ci touche 3 à 8 nouveaux nés pour 1000 naissances. La mortalité en période post-natale est de 25 à 50% des cas et ceux qui survivent développeront des troubles sévères (épilepsie, retard neuro-cognitif et comportemental, paralysie cérébrale…). Au cours de l’accouchement, l’asphyxie périnatale se caractérise par une diminution du pH artériel ombilical. Cette mesure du pH sanguin est donc la mesure de référence pour déterminer la sévérité de l’asphyxie.Une des voies étudiées pour améliorer le dépistage des fœtus à risque d’acidose est l’analyse des modifications du système nerveux autonome (SNA) par analyse de la variabilité du rythme cardiaque fœtal. En effet, la fréquence cardiaque fœtale est en permanence sous l’influence du système nerveux autonome et sa variabilité (VFC) est un reflet de la balance sympathique / parasympathique. Le CHU de Lille a développé une nouvelle méthode d’analyse continue de la VFC ayant montré son efficacité chez l’adulte et chez le nouveau né pour l’évaluation du SNA. L’objectif de ce travail de Thèse est d’adapter cette technologie à l’analyse du SNA fœtal pour obtenir un nouvel indice appelé Fetal Stress Index (FSI) et d’évaluer sa pertinence en situation d’acidose.Cette preuve de concept a été effectuée de manière expérimentale chez le fœtus de brebis. Elle s’est réalisée en 2 temps. Nous avons tout d’abord évalué la performance du FSI par rapport aux méthodes classiques d’analyse de la VFC en termes d’aptitude à détecter les variations du SNA. Après injection d’Atropine, parasympatholytique, ou de Propranolol, sympatholytique, nous avons montré que le FSI était une méthode efficace et spécifique d’évaluation des variations du tonus parasympathique du SNA. Cette étude a également montrée la supériorité du FSI par rapport aux méthodes classiques d’analyse de la VFC en termes de sensibilité et de spécificité. Dans un second temps, nous avons évalué ce nouvel indice comme facteur prédictif de l’état acido basique du fœtus dans 2 modèles expérimentaux d’occlusion cordonale. Dans le premier modèle, l’acidose était obtenue par une occlusion continue du cordon avec une réduction de partielle du débit ombilical. Dans le second, nous réalisions des occlusions totales répétées à intervalles réguliers afin de mimer les contractions utérines lors du travail. Dans les 2 études, nous avons observé une hausse du FSI en cas d’acidose avec une corrélation significative entre le FSI et le pH, mais aussi entre le FSI et les lactates dans le second modèle.En conclusion, le FSI constitue un bon reflet de l’activité parasympathique fœtale. Cet indice permet d’étudier les variations du SNA fœtal avec une meilleure sensibilité et une meilleure spécificité que les méthodes usuelles d’analyse de la VFC et semble bien corrélé à l’état acido basique fœtal. Il s’agit donc d’un indice prometteur qu’il sera intéressant d’incorporer dans une analyse multi paramétrique du rythme cardiaque fœtal
The monitoring of fetal well being during labor is essentially based on fetal heart rate (FHR) analysis. The recording of FHR, even continuously during labor, does not fully assess fetal oxygenation or neonatal risk of asphyxia. Indeed, this tool is imperfect and subjective with an important inter and intra-operator variability. Second-line examinations to characterize the fetal state are currently used in routine practice, i.e. scalp fetal blood sampling to study the fetal acid-base balance (pH or lactates) or scalp electrode placement to study the fetal ECG (ST segment analysis). These techniques are nevertheless invasive and subject to technical constraints. There is therefore an interest in developing both objective and non-invasive means of evaluating fetal wellbeing to reduce neonatal encephalopathy. Indeed, its prevalence is about 3 to 8 per 1000 births. Post natal mortality is about 25 to 50% and survivors will hav severe diseases (epilepsy, neurologic impairment, cerebral palsy…).One of the possibilities studied to better identify fetuses at risk for acidosis is the analysis of changes in the autonomic nervous system (ANS) in response to hypoxia.Indeed, the regulation of heart rate is dependent on the ANS and thus, its variability is a reflection of the sympathetic / parasympathetic balance. Analysis of heart rate variability (HRV) is a recognized non-invasive tool that is used to assess ANS regulation. The CHU Lille has developed a new continuous tool for the analysis of HRV, which demonstrated its efficacity in adults and neonates to evaluate the ANS. The objective of this thesis was to develop its index, called Fetal Stress Index (FSI), in the fetus and to evaluate it in conditions of acidosis.The study was experimental in a sheep model chronically instrumented and was in 2 steps. First, we evaluate the performance of our method compared to commonly used HRV analysis, regarding the ability to detect the variation of variations of the ANS. After injection of atropine, to inhibit parasympathetic tone, or propranolol to block sympathetic activity, we shown that our method appeared to be effective in detecting parasympathetic inhibition and, moreover, was superior to classical analysis of HRV in terms of sensibility and specificity.In a second time, we evaluated this new index as a predictive factor of the fetal acid-base state in 2 experimental models of fetal hypoxia by occlusion of the cord. In the first one, acidosis was obtained through a partial occlusion of the umbilical cord and in the second one, though repetitive complete occlusion as uterine contractions during labor. In those two studies, we observed a raise of our index in case of acidosis with a correlation beetween FSI and pH and also FSI and lactates in the second model.In conclusion, the FSI reflects fetal parasympathetic activity, has a better detection than others usual methods, and seems well correlated to fetal acid-base status. It is a promising index and it will be interesting to incorporate it in a multi parametric analysis of fetal heart rate to predict acidosis

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Alberton, Emanuele <1989&gt. "Stress Finanziario Sistemico: Sviluppo di un Indice e Confronto tra Eurozona e USA." Master's Degree Thesis, Università Ca' Foscari Venezia, 2013. http://hdl.handle.net/10579/3517.

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Con lo svilupparsi di cambiamenti strutturali come la liberalizzazione finanziaria e la globalizzazione dei sistemi finanziari, i policy maker hanno iniziato sempre più ad interessarsi alla stabilità finanziaria. Avvenimenti quali la crisi del Long-Term Capital Management, la bolla speculativa informatica del nuovo millennio e, soprattutto, la crisi finanziaria globale iniziata nel 2007 hanno rimarcato la necessità di comprendere la relazione tra sistema finanziario ed economia reale. Attraverso una revisione della letteratura accademica circa definizione e natura della stabilità dei sistemi finanziari, si procede al calcolo di un Indice di Stress Finanziario per gli USA e uno per l'Eurozona. Tale strumento risulta utile in più campi: in ambito accademico, per studiare i collegamenti tra stabilità finanziaria, stabilità monetaria ed economia reale; in ambito istituzionale, per calcolare lo stato di salute di un sistema finanziario al fine di decidere tempo e natura degli interventi di politica economica; in ambito aziendale, come strumento aggiuntivo per la valutazione degli investimenti. La scelta delle variabili che compongono gli indici si basa sulle best practice internazionali. Le variabili sono pesate mediante l'utilizzo della Principal Component Analysis (PCA), una tecnica econometrica, destinata alla riduzione della dimensionalità dei dati, che coglie i principali trend nascosti nella nuvola di osservazioni relative alle variabili di input.Questo elaborato approfondisce il tema della stabilità dei sistemi finanziari. Attraverso una revisione della letteratura accademica circa la sua definizione e la sua natura, si arriva al calcolo di un Indice di Stabilità Finanziaria per gli USA e uno per l'Eurozona. Tale strumento risulta utile in più campi: in ambito accademico, per studiare i collegamenti tra stabilità finanziaria, stabilità monetaria ed economia reale; in ambito istituzionale, per calcolare lo stato di salute di un sistema finanziario al fine di decidere tempo e natura degli interventi di politica economica; in ambito aziendale, come strumento aggiuntivo per la valutazione degli investimenti. Con lo svilupparsi di cambiamenti strutturali come la liberalizzazione finanziaria e la globalizzazione dei sistemi finanziari, i policy maker hanno iniziato sempre più ad interessarsi alla stabilità finanziaria. Avvenimenti quali la crisi del Long-Term Capital Management, la bolla speculativa informatica del nuovo millennio e, soprattutto, la crisi finanziaria globale iniziata nel 2007 hanno rimarcato la necessità di comprendere la relazione tra sistema finanziario ed economia reale. Attraverso una revisione della letteratura accademica circa definizione e natura della stabilità dei sistemi finanziari, si procede al calcolo di un Indice di Stress Finanziario per gli USA e uno per l'Eurozona. Tale strumento risulta utile in più campi: in ambito accademico, per studiare i collegamenti tra stabilità finanziaria, stabilità monetaria ed economia reale; in ambito istituzionale, per calcolare lo stato di salute di un sistema finanziario al fine di decidere tempo e natura degli interventi di politica economica; in ambito aziendale, come strumento aggiuntivo per la valutazione degli investimenti. La scelta delle variabili che compongono gli indici si basa sulle best practice internazionali. Le variabili sono pesate mediante l'utilizzo della Principal Component Analysis (PCA), una tecnica econometrica, destinata alla riduzione della dimensionalità dei dati, che coglie i principali trend nascosti nella nuvola di osservazioni relative alle variabili di input.

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Ferreira, Heloisa Aparecida 1966. "Intervenção fisioterapeutica reduz o indice de estresse em vestibulandos." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314617.

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Orientadores: Regina Celia Spadari, Dora Maria Grassi-Kassisse
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-13T08:58:41Z (GMT). No. of bitstreams: 1 Ferreira_HeloisaAparecida_M.pdf: 1416925 bytes, checksum: c164e67b3f6e3036b77bf57bb5259598 (MD5) Previous issue date: 2009
Resumo: Certo nível de estresse é benéfico ao desempenho e à sobrevivência, mas a constante ou inadequada resposta de estresse pode trazer sérios riscos à saúde e prejudicar o desempenho. Estudos com vestibulandos justificam-se pela alta concentração de cortisol encontrada em amostras de saliva coletadas nos meses em que são feitas as inscrições e nos dias dos exames vestibulares. Este trabalho propõe não somente avaliar os índices de estresse, mas também uma alternativa de abordagem terapêutica não medicamentosa para reduzir os índices de estresse no período que antecede o vestibular e, com isso, melhorar o desempenho nas provas. Em um primeiro estudo, o índice de estresse percebido foi avaliado em estudantes matriculados em um curso pré-vestibular, nos meses de março, setembro e novembro utilizando-se o Questionário de Estresse em Adolescentes (QEA). Os escores obtidos no QEA foram mais baixos em março do que em setembro e novembro, maior nas meninas que nos meninos e ainda diferentes entre os turnos matutino, vespertino e noturno. No estudo 2 uma mostra de 32 voluntários foi submetida à terapia manual de mobilização muscular e da fáscia, em duas sessões semanais, de 40 minutos, de setembro a novembro. Outro grupo não recebeu o tratamento. O índice de estresse percebido foi avaliado em setembro e, juntamente com a memória declarativa de curto e longo prazo, também na semana que antecedeu o exame vestibular. A concentração salivar de cortisol foi determinada em setembro e no dia do exame. Vestibulandos tratados não apresentaram aumento da concentração salivar de cortisol momentos antes da prova, ao contrário do que ocorreu com aqueles do grupo controle; apresentaram também menor escore no QEA, melhor desempenho nos testes de memória, e maior índice de aprovação na primeira fase do vestibular. Concluímos que a intervenção fisioterapêutica aplicada foi eficiente em reduzir o índice de estresse dos vestibulandos e resultou em melhor desempenho no exame.
Abstract: Although certain stress levels might be beneficial to the performance and survival, the constancy of stressors or an inadequate stress response may cause risks to health and may trigger or worsen a variety of diseases. In order to adopt preventive or curative strategies it is necessary to identify the high-risk groups by determining the stress levels. Studies in Brazilian adolescents during the year they are preparing to fight for a vacancy in the public universities are justified by the high concentration of cortisol, one of the stress hormones, found in these students? saliva samples, collected not only in the exams period but also during the period they do the option for the university they want to attend. The objective of this work is to determine the stress levels in students preparing to apply for the universities (study 1), and also to suggest an alternative of non-pharmacological therapy in order to reduce the stress levels in the students during the exam period and then, improving their performance (study 2). In the first study, we determined the perceived stress level in the students attending a preparatory course, in March (beginning of the school year), November (when they apply for the exams) and in November (in the week they do the exams) by using the Adolescent Stress Questionnaire (ASQ, Byrne, 2005). In the study 2, 32 volunteers were submitted to 40 min manual therapy, twice a week, from September to November. Another group of students not submitted to the therapy was evaluated as control. The cortisol concentrations were determined in four saliva samples collected during one day in the period of registration and on the day of the exam, the index of perceived stress and the performance in a memory test aimed to evaluate short and long term declarative memory were evaluated in the week before the exam. The results showed that the ASQ scores were lower in March than September and November. They also have shown that the students who had not undergone the manual therapy presented an increase in the concentration of salivary cortisol before the exam, what did not occurred with the students in the treated group. Moreover, the treated group also scored lower in the perceived stress questionnaire, exhibited a better performance in the short term memory tests and a higher rate of success in the exams. We concluded that the applied physiotherapy program was effective to reduce the students stress levels and improved their performance in the exam.
Mestrado
Fisiologia
Mestre em Biologia Funcional e Molecular

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Morin, Catherine. "Indice de stress financier pour le Canada : mesure de l'instabilité financière à l'aide de l'analyse en composantes principales." Thesis, Université Laval, 2014. http://www.theses.ulaval.ca/2014/30705/30705.pdf.

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Les marchés financiers sont souvent sujets à d’importantes perturbations, les plus récentes ayant été observées lors de la crise financière de 2008. Ces perturbations peuvent être qualifiées de stress financier, qui se définit comme une interruption du fonctionnement normal des marchés financiers. Ce mémoire propose de mesurer le stress du marché financier canadien, en s’inspirant de l’analyse effectuée par KLIESEN et SMITH [2010] pour les États-Unis. Ces auteurs, qui travaillent à la Réserve fédérale de Saint-Louis, proposent une approche basée sur une analyse en composante principale. Nos résultats montrent que le stress sur les marchés canadiens a une évolution similaire à celui des États-Unis. Un test de causalité de Granger indique que le stress financier américain cause du stress financier sur le marché canadien. Par la suite, la méthode d’analyse en composantes principales non linéaire par noyau (KPCA) est utilisée sur les données américaines et canadiennes. Cette nouvelle méthodologie permet de mieux illustrer le comouvement entre les séries temporelles, lorsque l’on admet des corrélations potentiellement non linéaires. Les résultats montrent que cette nouvelle méthode permet d’obtenir des graphiques dont le bruit est réduit, et avec des structures mieux définies. L’amplitude des évènements de stress est changée, mais l’indice garde la même évolution qualitative.
Financial markets are often affected by important perturbations, as witnessed during the 2008 financial meltdown. These perturbations can be seen as a form of financial stress and are defined as an interruption of normal working financial market. This thesis proposes to measure the financial stress in the Canadian market, using a principal component methodology used by the Saint-Louis Federal Reserve (KLIESEN and SMITH [2010]). Our results show that the financial stress occurring on the Canadian market is stongly related to financial stress: notably US financial stress granger causes financial stress on the Canadian market. Additionally, we use a kernel principal component analysis (KPCA) on both US and Canadian data, to account for second and third degree effects in covariance structures. The kernel analysis reduces the noise on the stress graph. Similar structures are visible and qualitative features are the same, but the relative amplitude of these structures is changed.

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Bolongo, Mpembe. "Effets de la CCK [indice] 4 et de différents stress expérimentaux sur les concentrations cérébrales de diverses amines biogènes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0019/MQ56867.pdf.

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Bolongo, Mpembe. "Effets de la CCK [indice] 4 et de différents stress expérimentaux sur les concentrations cérébrales de diverses amines biogènes." Sherbrooke : Université de Sherbrooke, 2000.

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Pirozzi, Flavio Fontes. "Relação entre o índice de massa corpórea, diabetes mellitus tipo 2, estresse oxidativo e polimorfismos nos genes da enzima conversora de angiotensina (ECA) e metilenotetrahidrofolato redutase (MTHRF) /." São José do Rio Preto, 2016. http://hdl.handle.net/11449/148006.

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Orientador: Milton Artur Ruiz
Coorientador: Claudia Regina Bonini Domingos
Banca: Antônio Carlos Pires
Banca: Sônia Maria Oliani
Resumo: Introdução: o aumento da prevalência da obesidade e do diabetes mellitus tipo 2 (DM2) é um grande desafio de saúde pública mundial e, por serem doenças heterogêneas e que elevam a chance do surgimento de doenças cardiovasculares, parâmetros de avaliação de risco são necessário na avaliação destes indivíduos. Objetivos: correlacionar diferentes variáveis como o índice de massa corpórea (IMC), os polimorfismos I/D ECA e C677T MTHFR e provas de estresse oxidativo em uma população de obesos brasileiros, com e sem diabetes, e doenças associadas com a síndrome metabólica. Casuística e métodos: avaliamos 125 indivíduos com obesidade (IMC maior ou igual a 30 Kg/m2 ) que foram divididos em dois grupos: grupo DM2 (obesos com DM2, n = 47) e grupo controle (obesos sem DM2, n= 78). Os pacientes do grupo DM2 apresentavam maior média de idade (p=0,02) e maior número de indivíduos com dislipidemia (p<0,05). Por meio de uma amostra de sangue periférico foi avaliado os polimorfismos I/D ECA e C677T MTHRF e as provas de estresse oxidativo, o TBARS e o TEAC. Resultados: na comparação entre os grupos com os polimorfismos analisados, não encontramos diferença significativa de chance de ocorrência e proteção para o DM2 em diferentes modelos de herança, na avaliação dos genótipos e no sinergismo entre eles. No polimorfismo I/D ECA, o genótipo mais frequente em ambos os grupos é o DD. Também não encontramos diferença significativa destes polimorfismos e as complicações microvasculares no grupo DM2. Correlacionando o IMC com o estresse oxidativo, encontramos uma correlação diretamente com o TBARS (r =0,7941) e inversamente proporcional com o TEAC (r=-0,6022) de forma significativa (p<0,0001). Entretanto, não houve diferença nos valores médios de TBARS e do TEAC entre os grupos DM2 e controle. O genótipo DD foi o mais frequente em ambos e o mesmo...
Abstract: Introduction: the increase in the prevalence of obesity and type 2 diabetes mellitus (T2DM) is a major global public health challenge and, because they are heterogeneous diseases that increase the chance of cardiovascular diseases, risk assessment parameters are necessary in the evaluation of these individuals. Aims: to correlate different variables such as body mass index (BMI), ACE I/D and MTHFR C677T polymorphisms, and oxidative stress tests in a population of obese Brazilians, with and without diabetes, and diseases associated with metabolic syndrome. Casuistry and methods: we evaluated 125 individuals with obesity (BMI greater than or equal to 30 kg /m 2 ) who were divided into two groups: T2DM group (obese with T2DM, n = 47) and control group (obese without T2DM, n = 78). Patients in the T2DM group presented higher mean age (p=0.02) and higher number of individuals with dyslipidemia (p<0.05). The ACE I/D and MTHRF C677T polymorphisms and the oxidative stress, TBARS and TEAC tests, were evaluated using a peripheral blood sample. Results: in the comparison between the groups with the analyzed polymorphisms, we do not find a significant difference in the chance of occurrence and protection for T2D in different inheritance models, in the evaluation of genotypes and in the synergism between them. In the ACE I/D polymorphism, the most frequent genotype in both groups is DD. We also do not find a significant difference of these polymorphisms and the microvascular complications in the T2DM group. Relating BMI to oxidative stress, we found a correlation directly with TBARS (r=0.7941) and inversely proportional to the TEAC (r =-0.6022) in a significant way (p <0.0001). However, there was no difference in the mean values of TBARS and TEAC between T2DM and control groups. The DD genotype was the most frequent in both, and the same is related to increased cardiovascular risk. In the ...
Mestre

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Main, Oscar. "Optimising forage maize's digestible yield under contrasted environments." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASB019.

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Le maïs occupe une place centrale dans le système fourrager français, son rendement et sa valeur énergétique étant deux critères clés pour l'inscription des variétés hybrides de maïs au catalogue officiel français. Des recherches antérieures ont montré une corrélation directe entre la valeur énergétique et la digestibilité de la matière sèche (MS), influencée par la digestibilité de la paroi, elle-même affectée par le déficit hydrique. Des études sur des lignées de maïs ont montré que le déficit hydrique sévère augmente la digestibilité de la MS et de la paroi, liées à une diminution de la teneur en lignine et à des changements dans sa distribution tissulaire. Cependant, comme la teneur en lignine a déjà été fixée dans les variétés hybrides, elle semble avoir peu de potentiel pour améliorer davantage la digestibilité de la paroi. Pour explorer d'autres cibles et l'impact du déficit hydrique sur ces caractères, ce travail de thèse a été mené dans le cadre du projet Carnot Plant2Pro INRAE-ARVALIS MAMMA MIA. Des variétés de maïs hybrides modernes, représentatifs du marché français actuel (maïs S0-S1 très précoces à précoces), ont été cultivés pendant deux ans dans seize conditions environnementales contrastées, dont six en conditions d'irrigation contrôlée. Tout d'abord, un indice de stress (SID) simple mais robuste a été établi, tenant compte du déficit hydrique du sol et de la température de l'air. Ce SID s'est révélé être un outil crucial en classant les différents environnements, mettant en évidence l'impact d'un stress sévère dû à des températures élevées sur la digestibilité de la MS par rapport à des conditions de stress modéré. Pour être en mesure d'étudier une large gamme de conditions environnementales, plusieurs équations de prédiction par spectroscopie proche infrarouge (NIRS) ont également été développées, capables de prédire de manière robuste et précise des caractères de la paroi et leurs relations, similaires à celles mesurées en biochimie au laboratoire. Bien que ces équations se révèlent suffisamment robustes pour être utilisées dans les programmes de sélection, une vigilance s'impose quant à l'exactitude des prédictions en conditions de stress, en particulier dans le cas des variétés hybrides où la gamme de variation des caractères est souvent limitée. L'ensemble des données obtenues a ensuite permis une analyse multi-échelle, intégrant des caractères agroclimatiques, agronomiques, biochimiques et histologiques, ainsi que des données expérimentales in sacco obtenues sur des vaches fistulées. Des cibles biochimiques et histologiques ont pu être proposées pour améliorer la qualité du maïs fourrager en fonction de l'intensité du stress. Nous avons montré qu'en condition de stress sévère, bien que la production d'épis diminue significativement, la digestibilité de la MS peut être maintenue grâce à une augmentation de la digestibilité de la paroi, due à une réduction de la teneur en acides p-hydroxycinnamique, alors que la teneur en lignine reste stable comme attendu. Nous avons également montré qu'en condition de stress modéré les caractères histologiques jouent un rôle aussi important que les caractères biochimiques, mais qu'une fois qu'un seuil est atteint, seuls les caractères biochimiques modulent les variations de la digestibilité de la paroi. Une fenêtre environnementale a donc pu être mise en évidence où le rôle accru de la distribution de la lignine aux côtés des caractères biochimiques permet une augmentation du rendement digestible. Ainsi, les agriculteurs pourraient exploiter cette fenêtre pour augmenter la productivité, en régulant l'irrigation en condition de sécheresse modérée et en intégrant le SID dans un outil de gestion de l'irrigation
Maize stands as a pillar of the French forage system, with its yield and silage feeding value serving as key criteria for the registration of maize hybrid varieties in the official French catalogue. Previous research on this topic has revealed a direct correlation between silage feeding value and dry matter (DM) digestibility, which is, in turn, constrained by cell wall (CW) digestibility and significantly affected by water deficit. Studies on maize inbred lines have shown that under severe water deficit conditions, both DM and CW digestibilities increase. This increase correlates with a decrease in lignin content and changes in lignin distribution. However, it is noteworthy that breeding efforts have already fixed lignin content in hybrid varieties. Therefore, lignin content is unlikely to be a source of future digestibility improvement. To explore other CW targets and the impact of water deficit on these traits, this PhD study was conducted as part of the Carnot Plant2Pro INRAE-ARVALIS MAMMA MIA project. We grew a range of modern forage maize hybrids representative of the current S0-S1 (very-early to early flowering earliness) French market for two years under sixteen contrasted environmental conditions, including six in controlled irrigation conditions. First, we established a simple but robust stress index (SID) that considers the water deficit in the soil and the air temperature. This SID provided a key environmental ranking tool, highlighting severe stress due to high temperature that significantly impacted DM digestibility compared to moderate stress conditions. Secondly, to encompass a wide range of environmental conditions in biochemical quantifications, we developed several predictive near-infrared spectroscopy (NIRS) equations capable of robustly and accurately predicting fine cell wall traits and relationships, mirroring levels observed in laboratory experiments. While these equations prove sufficiently robust for use in selection programs, we emphasize the need for vigilance in accurately estimating prediction accuracy under stress conditions, particularly in equations applied to hybrid material where trait variation ranges are often limited. The core dataset of this work enabled a multiscale analysis, integrating agroclimatic, agronomic, biochemical, and histological traits, along with in sacco experimental data on cows. We proposed biochemical and histological traits to improve the quality of forage maize depending on stress intensity. We demonstrated that under severe stress, ear production decreases significantly, but DM digestibility can be maintained by increasing CW digestibility. This boost in CW digestibility was due to a reduction in p-hydroxycinnamic acid content, while lignin content remained stable, as anticipated. The significance of lignin distribution increased with the severity of stress, reaching an extreme threshold where biochemical parameters solely account for digestibility variations. This two-threshold model presents a window of opportunity located at the first threshold between non-stressed and moderately stressed environments, where the increased role of lignin distribution alongside biochemical traits enabled an increase in digestible yield. By controlling irrigation doses in the field under moderate drought conditions and integrating the SID into an irrigation management tool, farmers could exploit this window to increase productivity

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9

Duprey, Thibaut. "Procyclicality of the banking sector : heterogeneity and extreme risk." Paris, EHESS, 2015. http://www.theses.fr/2015EHES0095.

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Pendant la récente crise financière, une attention particulière a été portée à la procyclicité des intermédiaires financiers. Cette thèse contribue à une meilleure compréhension de leur comportement au cours du cycle économique. Les deux premiers chapitres, en adoptant une approche plus microéconomique, analysent l'impact de certaines différences entre banques sur leur provision de crédit. Ainsi les banques détenues par l'État ont généralement une meilleure capacité d'absorption des chocs négatifs. Des cycles du crédit différenciés peuvent également résulter d'une externalité qui amène à distinguer les banques en fonction de leur efficacité dans leur acquisition d'information ; auquel cas, davantage d'hétérogénéité entre banques génère une mauvaise allocation du crédit et impacte négativement la productivité de l'économie. Dans une perspective plus macroéconomique, le troisième article se focalise sur la procyclicité du levier bancaire comme source de fragilité en cas de choc extrême. La procyclicité inhérente des forces de marché engendre une accumulation du risque, ce qui peut justifier une régulation du levier bancaire. Le dernier chapitre s'intéresse à l'interaction entre les cycles réels et financiers et permet d'identifier les événements de stress financier systémique, qui peuvent se définir comme des périodes de stress sévère et simultané sur plusieurs marchés. Ces travaux devraient contribuer à la mise en place d'un nouveau cadre réglementaire macroprudentiel
The procyclicality of financial intermediaries has been a key source of concern during the recent financial crisis. This thesis sheds a new light on several aspects of their behaviour over the economic cycle. The first two chapters take a bank level approach and analyse to which extent some type of heterogeneity among banks impacts the provision of credit throughout the cycle. I document that government-owned banks are usually in a better position to lend against the wind in periods of stress. Heterogeneous lending cycles can also arise as a result of an externality among banks more or less efficient in information acquisition, in which case, more banking heterogeneity distorts the allocation of credit and is detrimental to aggregate productivity. In a more macroeconomic perspective, the third chapter focuses on the procyclicality of banks' leverage as a source of fragility in case of extreme stress. The inherent procyclicality of market forces leads to an endogeneous build up of risk, which can justify bank leverage regulations. In the last chapter I investigate the interplay between the real and financial cycles and identify systemic financial stress events that can be understood as periods of severe and simultaneous stress on several markets. This work is particularly relevant for the new macroprudential regulatory framework

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Miller, Berry Juanita K. "How does stress induce headache? An experimental study." Thesis, Miller Berry, Juanita K. (2020) How does stress induce headache? An experimental study. Professional Doctorate thesis, Murdoch University, 2020. https://researchrepository.murdoch.edu.au/id/eprint/59729/.

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Psychological stress triggers headaches, but how this happens is unclear. To explore this, 38 episodic migraine sufferers, 28 with tension-type headache (T-TH) and 20 controls rated nausea, negative affect, task-expectancies and headache at 5-minute intervals during an unpredictable and uncontrollable 25-minute mental arithmetic task with a non-contingent failure rate. Blood pressure and pulse rate were measured every 3 minutes and salivary cortisol was sampled before and after the task. Trigeminal activation was measured by nociceptive blink reflex measures during each of the three experimental phases. Multiple regression analyses indicated that negative affect (NA) was the strongest predictor of headache intensity during the task. Increases in stress-headache were unrelated to consistent changes in cardiovascular activity but were related to declines in cortisol and increased post-task trigeminal activity. In repeated measures ANOVAs, participants who developed headache had higher nausea, NA and self-efficacy expectancies than those with no-or-low headache (p <.05 to p <.001). In further multiple regression analyses to identify which aspects of the stress process contributed to the high NA preceding headache, discouragement, anxiety, irritation and tension mediated the relationship between headache intensity during the stressful task and primary and secondary appraisal processes (stressor exposure and stressor reactivity). Avoidant coping, perceived inability to decrease pain, and outcome expectancy independently predicted headache intensity during the stressful task. Anxiety mediated the relationship between headache intensity and the coping tactics of wishful thinking, self-criticism, pain catastrophizing and praying/hoping. Attachment anxiety and the personality traits of openness, agreeableness and conscientiousness moderated the relationship between stress appraisals and headache. Results were discussed using the model of stress-headache as allostatic load. Findings suggest that headache developed when participants overextended themselves during a stressful task, adopting an information processing style which impeded emotional adjustment to changing situational demands. Learning to modify perceptions of threat and adopting a more flexible, less outcome-dependent processing style which avoids response conflict might help to prevent headache from spiralling upward.

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Seabra, Fátima Leal. "Effect of resveratrol in stress-induce premature senescent human fibroblasts." Master's thesis, Faculdade de Medicina da Universidade do Porto, 2009. http://hdl.handle.net/10216/52176.

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12

Rabideau, Christine L. "Pesticide Mixtures Induce Immunotoxicity: Potentiation of Apoptosis and Oxidative Stress." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/34547.

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The three insecticides of interest were lindane (an organochlorine), malathion (an organophosphate) and piperonyl butoxide (PBO; a synergist). Based on minimum cytotoxicity (> LC25), the following concentrations were chosen for the pesticide mixture studies: 70Î¼M lindane (Lind), 50Î¼M malathion (Mal) and 55Î¼M PBO. In the AlamarBlue cytotoxicity assay, individual pesticide and mixtures of malathion/PBO (MP) and malathion/lindane (ML) prompted cytotoxicity with varying intensities (Mal 18.8%, Lind 20.4%, PBO 23.5%, ML 53.6% and MP 64.9%). Cytopathological analysis revealed apoptotic features in treated cells and the DNA Ladder Assay confirmed the presence of DNA fragments. The specific mode of cell death was examined via the 7-aminoactinomycin D (7-AAD) Staining Assay. Apoptosis was detected in each treatment (Mal 6.5%, Lind 12.0%, PBO 13.2%, ML 19.3% and MP 23.4%). Furthermore, 7-AAD staining in combination with fluorescent-labeled monoclonal antibodies, PE-CD45RB/220 and FITC-CD90, was performed. B-cells were more susceptible to Mal and PBO treatments than were T-cells. The pro-oxidant activity of the pesticides was monitored via the Dichlorofluorescin Diacetate assay. Exposure to pesticides for 15 minutes increased H2O2 production above the controls, Mal 21.1%; Lind 10.8%; PBO 25.9%; ML 26.8%; MP 37.8%. The activities of antioxidant enzymes, glutathione peroxidase (GSH-Px) and glutathione reductase (GR) were altered by these treatments. GR was significantly reduced for the pesticide mixtures only (control: 51.7; Mal: 48.2; Lind: 50; PBO: 52.3; ML: 40.5; MP: 42 Units/mg). GSH-Px activity was severely reduced for all the pesticide treatments (control: 44.9; Mal: 30.2; Lind: 30.6; PBO: 32.4; ML: 21.1; MP: 21.1 Units/mg). These results indicate that exposure to these pesticide and pesticide mixtures induces apoptosis and oxidative stress.
Master of Science

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13

Seabra, Fátima Leal. "Effect of resveratrol in stress-induce premature senescent human fibroblasts." Dissertação, Faculdade de Medicina da Universidade do Porto, 2009. http://hdl.handle.net/10216/52176.

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14

Soury, Mariette. "Détection multimodale du stress pour la conception de logiciels de remédiation." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112278/document.

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Ces travaux de thèse portent sur la reconnaissance automatique du stress chez des humains en interaction dans des situations anxiogènes: prise de parole en public, entretiens et jeux sérieux à partir d'indices audio et visuels.Afin de concevoir des modèles de reconnaissance automatique du stress, nous utilisons : des indices audio calculés à partir de la voix des sujets, capturée par un micro cravate; et des indices visuels calculés soit à partir de l'expression faciale des sujets capturés par une webcam, soit à partir de la posture des sujets capturée par une Kinect. Une partie des travaux portent sur la fusion des informations apportées par les différentes modalités.L'expression et la gestion du stress sont influencées à la fois par des différences interpersonnelles (traits de personnalité, expériences passées, milieu culturel) et contextuelles (type de stresseur, enjeux de la situation). Nous évaluons le stress sur différents publics à travers des corpus de données collectés pendant la thèse: un public sociophobe en situation anxiogène, face à une machine et face à des humains; un public non pathologique en simulation d'entretien d'embauche; et un public non pathologique en interaction face à un ordinateur ou face au robot humanoïde Nao. Les comparaisons inter- individus, et inter-corpus révèlent la diversité de l'expression du stress.Une application de ces travaux pourrait être la conception d'outils thérapeutiques pour la maitrise du stress, notamment à destination des populations phobiques.Mots clé : stress, phobie sociale, détection multimodale du stress , indices audio du stress, indices faciaux du stress, indices posturaux du stress, fusion multimodale
This thesis focuses on the automatic recognition of human stress during stress-inducing interactions (public speaking, job interview and serious games), using audio and visual cues.In order to build automatic stress recognition models, we used audio cues computed from subjects' voice captured via a lapel microphone, and visual cues computed either form subjects' facial expressions captured via a webcam, or subjects' posture captured via a Kinect. Part of this work is dedicated to the study of information fusion form those various modalities.Stress expression and coping are influenced both by interpersonal differences (personality traits, past experiences, cultural background) and contextual differences (type of stressor, situation's stakes). We evaluated stress in various populations in data corpora collected during this thesis: social phobics in anxiety-inducing situations in interaction with a machine and with humans; apathologic subjects in a mock job interview; and apathologic subjects interaction with a computer and with the humanoid robot Nao. Inter-individual and inter-corpora comparisons highlight the variability of stress expression.A possible application of this work could be the elaboration of therapeutic software to learn stress coping strategies, particularly for social phobics.Key words: stress, social phobia, multimodal stress detection, stress audio cues, stress facial cues, stress postural cues, multimodal fusion

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15

Drozdova, Tetyana. "Nephrin missense mutations altez cellular trafficking and induce endoplasmic retioulum stress." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=106541.

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Nephrin, a key component of the filtration slit diaphragm, undergoes post-translational modifications in the endoplasmic reticulum (ER). Mutations in nephrin lead to proteinuria. We examined the effects of missense mutations in nephrin on protein folding in the ER, cellular trafficking, and induction of the unfolded protein response (UPR). Wild type (WT) nephrin and the I171N, G270C, S366R, S724C and R743C mutant cDNAs were expressed in 293T cells or glomerular epithelial cells (GECs) by transient transfection. Association of nephrin with the ER chaperone, calnexin, was studied by co-immunoprecipitation. Activation of the UPR was assessed by monitoring expression of the ER chaperone, Grp94, phosphorylation of eukaryotic translation initiation factor-2α subunit (eIF2α), and induction of C/EBP homologous protein-10 (CHOP), as well as activating transcription factor-6 (ATF6)-luciferase reporter activity. All nephrin mutants showed increased association with calnexin, compared with WT nephrin. The I171N and G270C mutants increased expression of Grp94 in 293T cells, and stimulated ATF6-luciferase activity in both 293T cells and GECs. Nephrin S366R and S724C tended to induce the UPR, but changes in Grp94 and ATF6-luciferase activity were less consistent. The R743C mutant did not enhance Grp94 expression, nor ATF6-luciferase activity. All nephrin mutants did not increase eIF2α phosphorylation, nor CHOP expression. Immunofluorescence microscopy showed WT nephrin at the plasma membrane, while the I171N and S366R mutants were perinuclear, colocalized with calnexin. Moreover, the two nephrin mutants induced aggregation of the ER chaperone, calreticulin, compared with WT. Treatment of cells with castanospermine (which reduces the interaction of nephrin with calnexin) resulted in a portion of nephrin I171N and S366R appearing at the plasma membrane. Thus, certain nephrin mutants show impaired folding in the ER, and activate the ATF6 branch of the UPR. Induction of ER chaperones may represent a cytoprotective response, allowing cells to withstand proteotoxic injury. Blocking the interaction of nephrin with calnexin results in a partial rescue of certain nephrin mutants to the plasma membrane.
La néphrine, un composant clé du diaphragme de fente, subit des modifications post-traductionnelles dans le réticulum endoplasmique (RE). Des mutations de la néphrine provoquent une protéinurie. Nous avons examiné les effets des mutations faux-sens de la néphrine sur le repliement de cette protéine dans RE, sur son trafic cellulaire et sur l'induction de réponse déplié protéines (UPR). Le type sauvage (TS) de la néphrine et les mutants d'ADNc, I171N, G270C, S366R, S724C et R743C ont été exprimés dans des cellules 293T ou cellules glomérulaires épithéliales (GECs) par une transfection transitoire. Association de néphrine avec le chaperon de RE, la calnexine, a été étudiée par la co-immunoprécipitation. Activation de l'UPR a été évaluée par l'étude de l'expression du chaperon du RE, Grp94, la phosphorylation de la sous-unité (eIF2α) du facteur 2α d'initiation de la traduction eucaryote, et l'induction de C/EBP homologue de la protéine-10 (CHOP), ainsi que l'activation du facteur-6 de la transcription (ATF6)- l'activité luciférase du gène rapporteur. Tous les mutants de la néphrine ont montré l'association accrue avec la calnexine, par rapport au TS de la néphrine. Les mutants I171N et le G270C ont augmenté l'expression du Grp94 dans les cellules 293T, ont stimulé l'ATF6-activité luciférase dans les deux cellules 293T et GECs. Néphrine S366R et S724C ont tendance à induire l'UPR, mais les changements dans le Grp94 et l'activité ATF6-luciférase ont été moins cohérents. Le mutant R743C n'a pas amélioré l'expression de Grp94, ni l'ATF6-activité luciférase. Tous les mutants de la néphrine n'ont pas augmenté ni la phosphorylation d'eIF2α, ni l'expression de CHOP. La microscopie en immunofluorescence a montré la localisation du TS néphrine à la membrane plasmique, tandis que les mutants I171N et S366R à la partie périnucléaire, colocalisés avec la calnexine. Par ailleurs, les deux mutants de néphrine ont provoqué l'agrégation du chaperon du RE, la calréticuline, par rapport au TS. Le traitement des cellules avec la castanospermine (qui réduit l'interaction de la néphrine avec la calnexine) a entraîné la localisation d'une partie des mutants I171N et S366R de la néphrine à la membrane plasmique. Ainsi, certains mutants de néphrine montrent une déficience du repliment de la protéine dans RE et activent la branche ATF6 de l'UPR. L'induction de chaperons du RE peut représenter une réponse cytoprotectrice, permettant aux cellules de résister aux lesions protéotoxique. Le blocage de l'interaction de la néphrine avec la calnexine resulte à un retour partiel au TS de certains mutants de néphrine, et donc à la localisation de néphrine à la membrane plasmique.

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16

Teowolde, Haile, Robert L. Voigt, Mahamoud Osman, and Albert K. Dobrenz. "Water Stress Indices for Research and Irrigation Scheduling in Pearl Millet." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/204250.

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The capability to measure the magnitude of water stress in plants is useful for precision irrigation scheduling and other purposes. This paper reports an evaluation of leaf (TL) and canopy (Tc) temperatures, leaf minus air (TL -Ta) and canopy minus air (Tc -Ta) temperatures, and leaf water stress index (LWSI) and crop water stress index (CWSI) in detecting stress in pearl millet (Pennisetum americanum (L.) Leeke) over two growing seasons. Baselines which were used to compute LWSI and CWSI were obtained. The upper and lower baselines for the Tc data, respectively, were Tc -Ta = 4.10 C and Tc -Ta = 3.87- .2001VPD where VPD is vapor pressure deficit in mbars. For the TL data, the upper and lower baselines, respectively, were TL -Ta = 1.97oC and TL -Ta = 1.308- .03006VPD. Tests against photosynthesis, transpiration, and grain yield showed that LWSI and CWSI are better indices of stress than TL -Ta, Tc -Ta, TL, Tc, or Ta. Average seasonal LWSI and CWSI ranged from approximately 0.03 for non- stressed to 0.80 for stressed plants. The reliability of LWSI and CWSI to detect stress and their relation with grain yield suggested the possibility of using these indices for irrigation scheduling decisions.

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17

Carroll, David A. "Drought and Nitrogen Effects on Maize Canopy Temperature and Stress Indices." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5932.

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Increased water scarcity due to changing climate, population growth, and economic development is a major threat to the sustainability of irrigated agriculture in the Western United States and other regions around the world. Management practices, such as controlled deficit irrigation, that seek to maximize the productivity of a limited water supply are critical. When using controlled deficit irrigation, remote sensing of crop canopy temperature is a useful tool for assessing crop water status and for more precise irrigation management. However, there is potential that nutrient deficiencies could compound the interpretation of water status from leaf temperature by altering leaf color and radiation balance. One objective of this thesis was to evaluate whether nitrogen fertility status of maize interacts with remotely sensed leaf temperature under full and limited irrigation. Another objective was to evaluate the effect of varying irrigation and nitrogen regimes on three water stress indices: Crop Water Stress Index (CWSI), Degrees Above Non-Stressed (DANS), and Degrees Above Canopy Threshold (DACT). Replicated studies were conducted using maize grown in both the glasshouse and the field. The glasshouse study consisted of combinations of well-watered and drought irrigation and sufficient and deficient nitrogen levels, while the field study consisted of combinations of well-watered, limited or controlled deficit, and drought irrigation and sufficient, sufficient delayed, and deficient nitrogen levels. In the glasshouse, leaf chlorophyll content was reduced moderately by limited irrigation and more so by N deficiency. For most observations in the glasshouse, the remotely sensed leaf temperatures were affected by irrigation, but not by N level. With drought irrigation, leaf temperature averaged 29.0° C, compared to 27.9 °C for the well-watered treatment. Similar results were observed in the field, illustrating the utility of canopy temperature in detecting water stress and that the measurement was not confounded by N status. It was also found that irrigation had a significant effect on all three water stress indices. For example, in the glasshouse, cumulative DANS was 32.2 for the drought treatment and 15.5 for the well-watered treatment. Similar results were found for other stress index measurements both in the glasshouse and the field. DANS underestimated stress on days when the reference crop was stressed and overestimated stress on low temperature days. DACT risks finding no stress when temperatures are below the canopy threshold temperature of 28.0 °C. Thus, CWSI is the most effective index, given that it takes humidity and air temperature into account. Indices were only weakly related to leaf area, biomass or grain yield, or crop water productivity. Linear regression of Nitrogen Sufficiency Index and its effect on crop growth found significant effects on biomass and grain yield, crop water productivity, and final leaf area. Thus, water stress indices are useful tools in evaluating crop water status, but consideration of other factors, such as nutrient status, must be taken for prediction of crop growth and yield.

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18

Baker, Sarah Ruth. "The effects of control, feedback and predictability on psychophysiological indices of stress." Thesis, University of Plymouth, 1994. http://hdl.handle.net/10026.1/2126.

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19

Aguilar, Jonathan P. "Historic changes of ecologically relevant hydrologic indices of unregulated Kansas streams." Diss., Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1387.

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20

Feehely, Kristie DeBlasio. "Relationship of Reproductive Hormone Levels and Menstrual Distress With Indices of Stress." NSUWorks, 2009. http://nsuworks.nova.edu/cps_stuetd/30.

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Previous research has found that hormone levels change throughout the phases of the menstrual cycle and can affect menstrual distress, however, with inconsistent results. Additionally, research has indicated that stress plays a role in menstrual distress symptoms. There has not been a comprehensive study to date which examines the relationship of reproductive hormone levels (e.g., progesterone, estradiol, LH and PRL) throughout all four phases of the menstrual cycle, while also studying menstrual distress symptoms and indices of stress. Participants include a community sample of women (N = 37) recruited at a university medical center in Mississippi who completed laboratory hormone assays, as well as the Menstrual Distress Questionnaire (Moos, 1968), the Weekly Stress Inventory (Brantley, Jones, Boudreaux, & Catz, 1997), and a global stress measure, throughout four phases of one menstrual cycle. Pearson correlations were conducted to test the potential relationships of hormone levels and indices of stress. The relationships between hormone levels and menstrual distress, as well as the relationships between menstrual distress and stress also were examined. Potential interactions were examined using multiple regressions. The role of menstrual distress in mediating the relationship between hormone levels and indices of stress also were considered and assessed using a series of multiple regression equations.

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Toczydlowski, David G. "Aquatic microbial community responses to stress: comparison of nontaxonomic and taxonomic indices." Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/45672.

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Three nontaxonomic indices; ATP/Chlorophyll a(ATP/Chla), ATP/ADP, and Chlorophyll a/Pheopigment (Chla/Pheo) were compared to the taxonomic measures of species diversity (d) and species richness as indicators of stress in aquatic environments. Field and laboratory microcosm responses of indigenous microbial communities exposed to municipal sewage treatment plant (STP) effluent were monitored. The STP effluent produced increased adenylate concentrations, ATP/ADP and ATP/Chla ratios, and decreased Chla, Chla/Pheo, d, and species richness relative to upstream reference communities. Nontaxonomic responses were consistent in four separate field tests.

Significant differences in responses were discernible in 3 d when communities were transferred from reference to polluted sites. Chla/Pheo decreased more rapidly than other measurements. The predictive capability of laboratory flowâ through microcosm tests was examined by simultaneously transferring communities from upstream reference sites to downstream field sites and to various dilutions of field effluent in the laboratory.

Master of Science

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22

Jia, Zhenquan. "Pesticides and Pesticide Mixtures Induce Neurotoxicity: Potentiation of Apoptosis and Oxidative Stress." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/28381.

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Several epidemiological studies have suggested a role for environmental chemicals in the etiology of neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease. Endosulfan (an organochlorine) and zineb (zinc-ethylene-bis-dithiocarbamate) are used as pesticides on a variety of crops worldwide and pose potential health risks to humans and animals. Both endosulfan and zineb are known to affect nervous system. Because the dopaminergic system continues to develop postnatally, we hypothesized that developmental exposure to endosulfan or zineb alone or in combination would result in alteration of nigrostrial neurotransmitters and would render the nigrostrial dopamine system more susceptible to chemical challenge later in life. The objectives of this study were (1) to determine the effects of endosulfan and zineb individually and in combination on dopaminergic or cholinergic pathways in vivo, (2) to investigate the effects of exposure to endosulfan, zineb and their mixtures administered in early life (during brain development) on subsequent exposure to these pesticides on the dopaminergic and cholinergic systems, in vivo, (3) to investigate the mechanism(s) of induction of neuronal cell death caused by these pesticides using human neuroblastoma SH-SY5Y cells in culture, (4) to define the role of oxidative stress in pesticide-induced neuronal cell death in vitro. Male C57Bl/6 mice of 7-9 months old exposed to zineb (50 and 100 mg/kg), endosulfan (1.55, 3.1 and 6.2 mg/kg) and their mixtures every other day over a 2-week period exhibited higher levels of dopamine accumulation in the striatum. Both pesticide-treated groups displayed significantly lower norepinephrine levels in the striatum (Ï ≤ 0.05) than the controls. The developmental exposure to zineb, endosulfan and their combination enhanced the vulnerability to subsequent neurotoxic challenges occurring later in life. Thus, C57BL/6 mice exposed to zineb, endosulfan and their mixtures as juveniles (postnatal days 5 to 19) and re-exposed at 8 months of age showed a significant depletion of striatal dopamine, to 22%, 16%, and 35% of control, respectively. Acetylcholinesterase activity in the cerebral cortex was found to be significantly increased in all pesticide treated groups. Mice given mixtures of pesticides also showed significantly increased levels of normal and aggregated alpha-synuclein, a hallmark of neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease. The results of these studies indicate that exposure to these pesticides as neonates and re-exposure as adults could result in neurochemical changes that did not reveal at adulthood when the exposure was at juvenile age only. We further investigated the mechanism(s) of activation of pesticide-induced neuronal cell death in vitro. The characteristic of cell death in SH-SY5Y human neuroblastoma cells was examined. These cells are known to retain catecholaminergic phenotype. Cells were exposed to endosulfan, zineb and mixtures of two pesticides, in concentrations ranging from 50 μM to 400 μM. These exposures caused both apoptotic and necrotic cell death in SH-SY5Y cells as evaluated by lactate dehydrogenase release, 7-aminoactinomycin-D and Annexin-V/PI assays. Exposure to mixtures of the pesticides enhanced both the early apoptosis and late apoptosis/necrosis compared to either chemical alone. Visual evaluation using DNA ladder assay and fluorescence Annexin V/PI assay confirmed the contribution of both apoptotic and necrotic events. Furthermore, endosulfan and zineb alone and in combination altered the caspase-3 activity indicating that both pesticides exposure exert their apoptotic effect via the caspase-3 pathway. Because there has been increasing evidence of the role of reactive oxygen species (ROS) and oxidative stress in pesticide-induced neuronal cell death (apoptosis and necrosis), the levels of ROS and antioxidant enzymes were examined. Cells treated with pesticides were found to enhance the generation of superoxide anion and hydrogen peroxide both in a dose- and time-dependent manner. Mixture of pesticides significantly enhanced the production of these reactive oxygen species compared to cells exposed to individual pesticide. Cells treated with pesticides showed a decrease in superoxide dismutase, glutathione peroxidase, and catalase levels. These pesticides also induced lipid peroxides (thiobarbituric acid reactive products) formation in SH-SY5Y cells. Furthermore, cells exposed to these pesticides were found to have increased in the expression of NFkappaB activity in the nucleus. These data support the hypothesis that oxidative stress was induced in neuronal cells by exposing to these pesticides in vitro. Taken together, the results of this study support the above hypothesis and suggest that the cytotoxicity of endosulfan and zineb and their combinations may, at least in part, be associated with the generation of ROS. Furthermore, mice exposed at early age and re-exposed at adulthood become more susceptible to alteration of neurotransmitter levels compared to mice exposed to these pesticides only as juveniles. These findings could add to the growing body of knowledge on the mechanism of pesticide-induced dopaminergic neuronal cell death and could hold tremendous implication for the future understanding of the possible involvement of environmental risk factors in the pathogenesis of Parkinson's disease.
Ph. D.

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23

Lounds-Singleton, Angela Jean. "Influence of thermal postharvest stress on mango (Magnifera indica) polyphenolics during ripening." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0002724.

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24

FALCIONI, Maria Letizia. "Pyrethroid insecticides induce oxidative stress, immuno and neuro-toxicity in Wistar rats." Doctoral thesis, Università degli Studi di Camerino, 2010. http://hdl.handle.net/11581/401922.

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Pyrethroids (Cypermethrin CY, Permethrin PERM, etc.) are widely used insecticides of low acute toxicity in mammals, however there are serious concerns on the risks related to their exposure. They mainly act on central nervous system and show significant effects on peripheral nerves, muscles and immune system. In this work, the effects of CY and/or PERM exposure on pup (1/10 LD50, 10 days) and adolescent (1/10 LD50, 60 days) rats were investigated. In particular the implications of pyrethroids exposure on immune and central nervous system were studied. Pyrethroids impair both monocytes and PMNs respiratory burst. They reduce reactive oxygen species production in activated monocytes while increase their level in PMNs. In vivo antioxidant supplementation (Vitamin E and/or Coenzyme Q10) can protect against the abnormal respiratory burst observed in PMNs from adolescent rats. In vivo and in vitro studies suggest physico-chemical changes at plasma membrane level in leukocytes. Moreover, pyrethroids induce protein and lipid oxidation in white blood cells. These insecticides increase protein oxidation also in striatum where PERM depletes GSH (both in pups and adolescent rats). In vivo Vitamin E supplementation restores the GSH level to the control value observed in adolescent rats. Moreover, antioxidant supplementation protects striata from the PERM induced DNA damage. PERM induces single and double-strand breaks as shown by comet assay. Modified versions of comet assay were performed in order to better characterize PERM induced DNA damage. With the aim to evaluate the role of mitochondrial superoxide anion on DNA damage, in vitro studies on striatal sub-mitochondrial particles (SMPs) were performed. In our experimental conditions, PERM inhibits mitochondrial complex I activity. This effect discards the involvement of mitochondria reactive oxygen species in the striatum DNA damage, while focalizes the main role of PERM on other oxidative stress pathways. The pivotal role of oxidative stress in PERM induced damage is underscored by the fact that in vitro GSH supplementation or pre-treatment prevents PERM induced DNA damage.

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Weber, Darren Lee, and darrenleeweber@gmail com. "EVENT-RELATED POTENTIAL INDICES OF ATTENTION AND MEMORY IN POST-TRAUMATIC STRESS DISORDER." Flinders University. Psychology, 2004. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20070702.080042.

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Background Previous reports of abnormal auditory N2 and P3 event-related potentials (ERPs) suggest impaired discrimination, evaluation or context updating for infrequent target stimuli in post-traumatic stress disorder (PTSD). This study examines each of these processes by investigating high-resolution ERP topography during target detection for visual word stimuli. Method ERPs were recorded at 124 electrodes from 10 PTSD patients and 10 matched controls. Target detection tasks comprised blocks of equally probable red and blue words, with low probability target events. Detection of fixed target words in one color provided the basis for measurement of selective attention for color, stimulus evaluation and target detection processing. Alternative task instructions, with the same stimuli, required detection of any consecutive word repeats in an attended color, which demands working memory updating for nontarget words. Comparison of attended non-target words from each task indicates the extra activity for updating working memory representations of target attributes. Thus, specific condition comparisons provide measures of stimulus discrimination and evaluation, working memory updating and target detection. Results PTSD patients had slower and less accurate motor responses in both tasks, with greater inaccuracy during the variable target task. There was abnormal ERP activity in PTSD at 200-300 ms in the left posterior temporal region during stimulus discrimination and target recognition. During evaluation of attended non-target words, PTSD patients demonstrate deficits in frontal and parietal regions at 400-500 ms. During working memory updating, at 400-600 ms, there was a delay in frontal activation, followed by smaller activity in parietal areas in PTSD. During target word recognition, PTSD patients demonstrate deficits in frontal activity, with greater occipital and parietal activity. Conclusions These findings indicate impaired evaluation and integration of new information in working memory. In particular, the results suggest failure in frontal executive systems, with greater dependence on visual processing for effective target detection. The current findings are consistent with neuropsychology studies that identify deficits of attention and memory for verbal information in PTSD. This study provides insight into the temporal components of attention and working memory in PTSD. It is proposed that working memory deficits arise from disruption to synchronized activity in distributed networks engaged in working memory processes.

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Reinerman, Lauren E. Ph D. "Cerebral Blood Flow Velocity and Stress Indices as Predictors of Cognitive Vigilance Performance." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1212092469.

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27

Shamir, Eylon. "Use of streamflow indices in hydrologic modeling." Diss., The University of Arizona, 2003. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_2003_396_sip1_w.pdf&type=application/pdf.

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Kariya, Chirag T. "Role of glutathione in lung's adaptive response against environmental agents that induce oxidative stress /." Connect to abstract via ProQuest. Full text is not available online, 2007.

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Asano, Shinichi. "Aging influences multiple indices of oxidative stress in the heart of the Fischer 344/NNia x Brown Norway/BiNia rat." Huntington, WV : [Marshall University Libraries], 2007. http://www.marshall.edu/etd/descript.asp?ref=735.

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Theses (M.S.)--Marshall University, 2007.
Title from document title page. Includes abstract. Includes vitae. Document formatted into pages: contains ix, 81 pages including illustrations. Bibliography: p. 69-77.

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Secor, Jordan Douglas. "Phytochemical Antioxidants Induce Membrane Lipid Signaling in Vascular Endothelial Cells." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338391553.

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31

Wilkinson, David Michael. "Physiological indices of acute fatigue during recovery from short-term training stress in distance runners." Thesis, University of Chichester, 2003. http://eprints.chi.ac.uk/798/.

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The studies described in this thesis were undertaken to investigate the physiological responses to short-term training stress in male distance runners. The aim of the thesis was to identify practical physiological markers of training stress that could identify acute fatigue and hence determine recovery status within a physical training programme. Study 1 investigated the physiological responses of 6 well-trained runners and 6 active but untrained individuals to 15 min of moderate intensity (70 % VO,max) treadmill running performed immediately before, 1,48 and 96 h following a treadmill run to exhaustion at 75% VO,max (Exh75%). The trained group ran for 107.1 ± 6.5 min before exhaustion in comparison to untrained group who ran for 60.6 ± 3.9 min.

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Dhawan, Sonia. "Caregiving stress and acculturation in East Indian immigrants caring for their elders." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0012/NQ27821.pdf.

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33

Weatherbee, Jessica L. "Exploiting DNA Repair and ER Stress Response Pathways to Induce Apoptosis in Glioblastoma Multiforme: A Dissertation." eScholarship@UMMS, 2016. https://escholarship.umassmed.edu/gsbs_diss/865.

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Glioblastoma multiforme (GBM) is a deadly grade IV brain tumor characterized by a heterogeneous population of cells that are drug resistant, aggressive, and infiltrative. The current standard of care, which has not changed in over a decade, only provides GBM patients with 12-14 months survival post diagnosis. We asked if the addition of a novel endoplasmic reticulum (ER) stress inducing agent, JLK1486, to the standard chemotherapy, temozolomide (TMZ), which induces DNA double strand breaks (DSBs), would enhance TMZ’s efficacy. Because GBMs rely on the ER to mitigate their hypoxic environment and DNA repair to fix TMZ induced DSBs, we reasoned that DSBs occurring during heightened ER stress would be deleterious. Treatment of GBM cells with TMZ+JLK1486 decreased cell viability and increased cell death due to apoptosis. We found that TMZ+JLK1486 prolonged ER stress induction, as indicated by elevated ER stress marker BiP, ATF4, and CHOP, while sustaining activation of the DNA damage response pathway. This combination produced unresolved DNA DSBs due to RAD51 reduction, a key DNA repair factor. The combination of TMZ+JLK1486 is a potential novel therapeutic combination and suggests an inverse relationship between ER stress and DNA repair pathways.

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Jenkinson, Alison McEwan. "The effect of polyunsaturated fatty acids and vitamin E on indices of oxidative stress in humans." Thesis, University of Aberdeen, 1999. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU536791.

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The aim of this thesis was to assess the effect of different of intake of polyunsaturated fatty acids on indices of oxidative stress, particularly damage to lipids and DNA and to examine whether this effect could be modified by supplementation with the lipid soluble antioxidant, vitamin E. This was assessed using a split plot/change over dietary study, where half and volunteers consumed a diet containing 5% PUFA (low PUFA) as food energy for 4 weeks and after a washout period of up to 10 weeks, consumed a 15% PUFA (high PUFA) diet for another 4 weeks. The other volunteers completed this protocol in reverse. Total fat, carbohydrates and protein, and vitamins E and C contents of the diets were constant and they were provided either with or without an additional 80mg d-tocopherol acetate/day. The results showed that although plasma total cholesterol showed a small significant increase after the low PUFA diets there was no change after consumption of the high PUFA diets or either of the vitamin E supplemented diets. Indices of oxidative stress (whole blood oxidised glutathione and urinary thiobarbituric acid reactive substances (TBARS)) were increased following consumption of the high PUFA diet. However, there was no change in non-specific plasma indices of lipid peroxidation, conjugated dienes and TBARS, nor in red cell antioxidant enzymes, glutathione reductase, and catalase. These results indicate that increasing dietary levels of PUFA may adversely affect some indices of lipid peroxidation, DNA damage and antioxidant status whilst not appearing to improve lipoprotein profiles. Increasing the dietary intake of vitamin E appears to ameliorate the potentially damaging effects of PUFA. Therefore, care should be taken when providing dietary advice on PUFA intake and an adequate intake of antioxidants to match any increased PUFA may be important for preventing oxidative stress.

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Weatherbee, Jessica L. "Exploiting DNA Repair and ER Stress Response Pathways to Induce Apoptosis in Glioblastoma Multiforme: A Dissertation." eScholarship@UMMS, 2008. http://escholarship.umassmed.edu/gsbs_diss/865.

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Glioblastoma multiforme (GBM) is a deadly grade IV brain tumor characterized by a heterogeneous population of cells that are drug resistant, aggressive, and infiltrative. The current standard of care, which has not changed in over a decade, only provides GBM patients with 12-14 months survival post diagnosis. We asked if the addition of a novel endoplasmic reticulum (ER) stress inducing agent, JLK1486, to the standard chemotherapy, temozolomide (TMZ), which induces DNA double strand breaks (DSBs), would enhance TMZ’s efficacy. Because GBMs rely on the ER to mitigate their hypoxic environment and DNA repair to fix TMZ induced DSBs, we reasoned that DSBs occurring during heightened ER stress would be deleterious. Treatment of GBM cells with TMZ+JLK1486 decreased cell viability and increased cell death due to apoptosis. We found that TMZ+JLK1486 prolonged ER stress induction, as indicated by elevated ER stress marker BiP, ATF4, and CHOP, while sustaining activation of the DNA damage response pathway. This combination produced unresolved DNA DSBs due to RAD51 reduction, a key DNA repair factor. The combination of TMZ+JLK1486 is a potential novel therapeutic combination and suggests an inverse relationship between ER stress and DNA repair pathways.

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Chu, Denise A. "The enduring effects of early life stress on psychological health and neural indices of emotion processing in healthy adults and adults with Posttraumatic Stress Disorder." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/18196.

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The relative impacts of distinct types of early life stress (ELS) and adult trauma exposure on clinical and neural indices of emotion processing in healthy and Posttraumatic Stress Disorder (PTSD) adults were investigated. Distinct ELS event clusters were identified from a large cohort of nonclinical Australian community adults (N=1,209) using principal component analysis, and entered into hierarchical multiple regression analyses predicting clinical indices of psychological health in the study sample. ELS involving ‘Interpersonal violation’ (ELS-‘Interpersonal violation’) was found to be differentially associated with higher self-reported depressive and anxiety symptoms, relative to other types of ELS (ELS-‘Other’) and adult trauma exposure in nonclinical adults. The relative impacts of ELS-‘Interpersonal violation’, ELS-‘Other’ and adult trauma exposure on neural indices of emotion processing in a subset of healthy non-clinical and PTSD adults were assessed using N170 evoked response potential (ERP) peak amplitudes to emotion faces. Hierarchical multiple regression analyses showed that greater ELS-‘Interpersonal violation’ exposure was associated with reduced differentiation in N170 responses between non-threat (happy) and threat (angry, fear) faces in healthy and PTSD adults. Repeated measures ANCOVAs comparing healthy and PTSD adults with high or minimal ELS-‘Interpersonal violation’ exposure, indicated greater ELS-‘Interpersonal violation’ exposure and PTSD were both associated with significantly dampened N170 responses to salient emotion faces. Higher PTSD avoidance also predicted attenuated N170 responses to happy faces. These findings were evident after accounting for the effects of sociodemographic and medication factors, clinical symptoms and other types of trauma exposure. Results indicate ELS-‘Interpersonal violation’ is associated with deficient discrimination of threat and dampened responses to emotion faces generally, and PTSD avoidance with dampened response to happy faces, during automatic cortical processing. Deficient threat discrimination and dampened responsivity to emotion stimuli accompanying avoidance, are likely contributors to increased risks and chronicity of PTSD associated with greater ELS-‘Interpersonal violation’ exposure.

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O'Loughlin, James H. "Can virtual reality scenarios induce acute anxiety within an experimental setting?" Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2024. https://ro.ecu.edu.au/theses/2769.

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The noradrenergic system is engaged by arousal and novel stimuli, and has a widespread influence throughout the body, indirectly innervating areas that control heart rate, respiratory rate, perspiration rate, pain sensitivity, and pupil diameter. This study aimed to create anxiety using threatening virtual reality protocols and determine whether that anxiety was sufficient to cause physiological responses consistent with locus coeruleus activation and thus noradrenaline release. Ten participants were exposed to three different types of virtual reality protocol (relaxing, implied threat and overt threat) and one mental arithmetic protocol, each designed to elicit a different level of anxiety for comparison. Anxiety level was assessed after each protocol using a five-point Likert scale, with a minimum of 1 (not anxious at all) and maximum of 5 (extremely anxious). While experiencing these protocols pupil diameter, pressure pain threshold, heart rate, and galvanic skin resistance were recorded. These autonomic and sensory measures are known to be influenced by locus coeruleus activation and noradrenaline release. Increases in pupil diameter, in particular, are correlated with locus coeruleus activity. Virtual reality threat protocols were successful in promoting anxiety in participants, however, the mental arithmetic protocol created greater anxiety. Virtual reality threat protocols resulted in significant increases in two of the outcome measures (pupil diameter and pressure pain threshold) and had a median anxiety score of ≤ 2.5, while mental arithmetic resulted in significant changes in three of the outcome measures (pupil diameter, pressuanixre pain threshold, galvanic skin resistance) and a median anxiety score of 3. Exploratory repeated measures correlations showed that pupil diameter correlated with pressure pain threshold (rrm = 0.27 [0.029, 0.49], p = 0.03), pressure pain threshold with galvanic skin resistance (rrm = -0.3 [-0.5, -0.075], p = 0.01), and galvanic skin resistance with heart rate (rrm = -0.36 [-0.57, -0.17], p = 0.00095). Changes in more responses with greater anxiety may suggest a staggered sensitivity of the outcome measures, with pupil diameter and pressure pain threshold being more sensitive to noradrenaline release than galvanic skin resistance and heart rate. The findings of this study indicate that the virtual reality protocols can successfully create anxiety sufficient to cause physiological responses consistent with some noradrenaline release by locus coeruleus activation. However, the amount of anxiety and degree of physiological responses were lower compared to that caused by mental arithmetic. Nonetheless, the versatility and control that the virtual reality medium offers allows the creation of virtual reality protocols that use tension and suspense to create mild anxiety. Thus, virtual reality protocols may be a more appropriate choice when measuring certain noradrenergic effects under conditions precluding movement and speech.

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38

Latsko, Maeson Shea. "Neuroendocrine and Gene Expression Changes Indicate Adult Phenotypic Responses to Periadolescent Social Stress." Kent State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=kent1435757204.

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39

Leslie, Karin. "Apoptosis, oxygen signaling and oxidative stress in first trimester pregnancies with high resistance uterine artery Doppler indices." Thesis, St George's, University of London, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.686434.

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The mechanisms of deficient placentation in the first trimester remain poorly understood although apoptosis, hypoxia and oxidative stress have all been implicated. High uterine artery Doppler (UtAD) resistance indices (RI), indicative of poor uterine blood flow, have been shown to be predictive of placental complications of pregnancy such as pre-eclampsia (PE), fetal growth restriction (FGR) and stillbirth. We investigated these pathways in placental tissue from first trimester pregnancies characterised by their risk of developing placental complications. We provide evidence that, even in the first trimester, pregnancies with high UtAD RI demonstrate alterations in placental gene and protein expression. Illumina gene microarray analysis demonstrated that first trimester pregnancies with high RI have differentially regulated placental gene expression in pathways relating to immune and inflammatory response, cell motility, cell cycle and apoptosis compared with normal RI pregnancies. Apoptotic markers are significantly higher in high RI placental tissue as determined by western blot analysis of cleaved PARP and caspase 3. Protein expression of the trophoblast survival factor IGF2 is significantly lower. Both high RI and normal RI placental tissue show evidence of hypoxia and oxidative stress, with expression ofHIFla and 2a, HSP 70, presence ofnitrotyrosine residues and lipid peroxidation. We found no exaggerated placental hypoxia or oxidative stress associated with high RI pregnancies, in fact there was significantly lower HIFla protein in these cases. High RI placental tissue demonstrates an altered balance of antioxidant enzyme activity in response to this oxidative stress with significantly lower glutathione peroxidase activity and higher superoxide dismutase activity when compared with normal RI placental tissue. Hypoxia and oxidative stress appear to be a physiological state in early pregnancy, with our data not supporting the concept these are associated with deficient placentation in the first trimester. Higher levels of apoptosis, reduced IGF2 expression and altered antioxidant defences may contribute to abnormal placentation and the later development of pregnancy complications such as PE, FGR and stillbirth.

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40

Macdonald, Luke Andrew. "The Effects of Mindfulness Training on Indices of Cognition, Stress and Immune Function in Team-Sport Athletes." Thesis, Griffith University, 2017. http://hdl.handle.net/10072/367264.

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Human potential is a fascinating concept. The saying, ‘you can achieve anything if you set your mind to it,’ has certainly passed through my ears on many occasion. I look at some of the greatest athletes in recent history: Michael Phelps, Kelly Slater, Roger Federer, Kobe Bryant in awe of what they have achieved and wonder: what makes them so great? How have they managed to achieve what they have? Undoubtedly, incredible natural talent, physical stature, and mental attributes such as determination, perseverance and self-belief contribute to their success. But I’ve always believed there’s more to it; they all possess the ability to achieve a superlative mental focus during competition. But how do they put their entire focus on the task at hand in such highly stressful and physically demanding situations? Could it be that they have the ability to achieve a heightened state of mindfulness? In 2014, the Seattle Seahawks achieved the unthinkable and won the 48th Super Bowl; the 2014 NFL championship. Head coach, Pete Carroll, attributed their success to the help of Michael Gervais, one of the world’s leading performance psychologists. In an interview following the Super Bowl win, Gervais was asked, ‘Obviously your end goal was winning, but what were your strategies with the Seahawks?’ At that point, Gervais’s tone of voice changed, almost concerned, and responded: ‘See, we don’t talk about winning. The goal for us is to be fully engaged at a really rich level to figure out and explore what is possible in your own life. And, if you get enough people resonating in that space, winning just happens as a result of this.’ Michael Gervais brought mindfulness training to the Seattle Seahawks and it has since become an integral part of their training regime.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Allied Health
Griffith Health
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41

Lehmann, Adam Clay. "AN ANALYSIS OF RELATIONSHIPS BETWEEN MODELED HYDROLOGIC/SEDIMENT LOADS AND INDICES OF IN-STREAM PHYSICAL HABITAT QUALITY IN HEADWATER STREAMS OF SOUTHWEST OHIO." Miami University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=miami1292959248.

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42

Bertaggia, Marco. "Ricerca di nuovi indici molecolari e microbiologici dello stato nutrizionale della vite." Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3423016.

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The study of soil-plant relationships is a prerequisite for controlling production of the vineyard. In vineyard sites of Gambellara, we studied the relationship between productivity, the main physico-chemical properties of soils and some innovative indices for the diagnosis of the nutritional status of the grape as i) the biodegradation capacity of organic matter evaluated by means of degradation of filaments of vegetal and animal origin and ii) the expression of genes that could be involved in defence mechanisms of grape to abiotic stress. Large and significant differences (p<0.05) were observed for physical and chemical fertility parameters evaluated. The vineyards characterized by high productivity are those showing a neutral pH, good supply of organic matter and adequate C/N ratio. These soils also showed high biodegradation of organic matter determined through the soil filaments degradation. The ARISA analysis (Amplified Ribosomal Intergenic Spacer Analysis), carried out on DNA samples isolated through an automatic procedure, showed that sites Pio Paulsen and Pio Carenza, characterized by low biodegradation capacity of organic matter, have a reduced genetic similarity compared to sites Chiarafontana and Branco viceversa characterized by high biodegradation capacity. Furthermore, the number of ARISA peaks, index of the number of soil bacterial species, was was statistically lower (p <0.05) in sites Pio Paulsen and Pio Carenza with respect to sites Chiarafontana and Branco. Plants of Campilonghi’s vineyard which is characterized by acid pH, scarce organic matter content, low C/N ratio, limited degradation capacity of filaments and low leaves content of nitrogen and sulphur showed, with respect plants of Pio Paulsen involved as control, up-regulation of WRKY, SuSy, PAL and STS1 genes. In conclusion, the degradative capacity of filaments and the assays of expression of above genes seem to be valid indicators of soil fertility and grape nutritional status.
Lo studio della relazione suolo-pianta è un presupposto fondamentale per il controllo vegeto-produttivo del vigneto. In siti vitati della zona D.O.C. di Gambellara, ci si è proposti di studiare la relazione fra la produttività, le principali caratteristiche fisico-chimiche del suolo e alcuni indici innovativi per la diagnosi dello stato nutrizionale della vite quali la capacità biodegradativa della sostanza organica valutata mediante la degradazione di fili di natura vegetale e animale inseriti nel suolo e la valutazione dell’espressione di geni che potrebbero essere coinvolti nei meccanismi di difesa della vite dagli stress abiotici. Ampie e significative differenze (p<0,05) sono state riscontrate fra i parametri di fertilità fisico-chimica esaminati. I vigneti caratterizzati da maggiore produttività sono quelli che evidenziano valori di pH neutro, buona dotazione di sostanza organica e un adeguato rapporto C/N. Questi suoli presentano, inoltre, elevata capacità biodegradativa della sostanza organica determinata in base alla degradazione dei fili immessi nel suolo. L’analisi ARISA (Amplified Ribosomal Intergenic Spacer Analysis), eseguita su campioni di DNA estratto da suolo in maniera automatizzata tramite la messa a punto di un nuovo protocollo, ha evidenziato che i siti Pio Paulsen e Pio Carenza, caratterizzati da bassa attività biodegradativa della sostanza organica, hanno una ridotta similarità genetica rispetto ai siti Chiarafontana e Branco caratterizzati viceversa da pronunciata attività biodegradativa. Inoltre, il numero di picchi ARISA, indice della numerosità delle specie batteriche presenti nel suolo, è risultato statisticamente inferiore (p<0,05) nei siti Pio Paulsen e Pio Carenza rispetto ai siti Chiarafontana e Branco. Nelle piante del sito Campilonghi che è caratterizzato da pH acido, scarsa dotazione di sostanza organica, basso rapporto C/N, limitata attività degradativa dei fili vegetali e da basso contenuto fogliare di azoto e zolfo è stata riscontrata la sovra-espressione, rispetto al sito di controllo Pio Paulsen, dei geni WRKY, SuSy, PAL e STS1. In conclusione, la capacità degradativa dei fili e la valutazione dell’espressione dei suddetti geni sembrano essere dei validi indicatori della fertilità del suolo e dello stato nutrizionale della vite.

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Magnuson, Scott A. "Developing New Indices for the Identification of Poor Effort." Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1241808636.

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LO, GALBO Valentina. "Valutazione del potenziale anticancro del frutto di Mangifera indica proveniente dalle aree rurali siciliane." Doctoral thesis, Università degli Studi di Palermo, 2022. http://hdl.handle.net/10447/533948.

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45

Di, Corleto Ross, and mikewood@deakin edu au. "The Evaluation of heat stress indices using physiological comparisons in an alumina refinery in a sub-tropical climate." Deakin University, 1998. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20050915.124324.

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The production of alumina involves the use of a process known as the Bayer process. This method involves the digestion of raw bauxite in sodium hydroxide at temperatures around 250°C. The resultant pregnant liquor then goes through a number of filtering and precipitation processes to obtain the aluminium oxide crystals which are then calcined to obtain the final product. The plant is situated in a sub tropical climate in Northern Australia and this combined with the hot nature of the process results in a potential for heat related illnesses to develop. When assessing a work environment for heat stress a heat stress index is often employed as a guideline and to date the Wet Bulb Globe Temperature (WBGT) has been the recommended index. There have been concerns over the past that the WBGT is not suited to the Northern Australian climate and in fact studies in other countries have suggested this is the case. This study was undertaken in the alumina plant situated in Gladstone Queensland to assess if WBGT was in fact the most suitable index for use or if another was more applicable. To this end three indices, Wet Bulb Globe Temperature (WBGT), Heat Stress Index (HSI) and Required Sweat Rate (SWreq) were compared and assessed using physiological monitoring of heart rate and surrogate core temperature. A number of different jobs and locations around the plant were investigated utilising personal and environmental monitoring equipment. These results were then collated and analysed using a computer program written as part of the study for the manipulation of the environmental data . Physiological assessment was carried out using methods approved by international bodies such as National Institute for Occupational Safety & Health (NIOSH) and International Standards Organisation (ISO) and incorporated the use of a Physiological Factor developed to enable the comparison of predicted allowable exposure times and strain on the individual. Results indicated that of the three indices tested, Required Sweat Rate was found to be the most suitable for the climate and in the environment of interest. The WBGT system was suitable in areas in the moderate temperature range (ie 28 to 32°C) but had some deficiencies above this temperature or where the relative humidity exceeded approximately 80%. It was however suitable as a first estimate or first line indicator. HSI over-estimated the physiological strain in situations of high temperatures, low air flows and exaggerated the benefit of artificial air flows on the worker in certain environments ie. fans.

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46

Fujii, Ashley Blostein. "Effects of zinc or citrus flavonoid supplementation on indices of oxidative stress in non-insulin-dependent diabetic women /." The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487935958846103.

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47

Snyder, Jarin T. "ER Stress and ATF6alpha potently induce S-Phase in Old Mouse Beta Cells Cultured Ex-Vivo in High Glucose." eScholarship@UMMS, 2020. https://escholarship.umassmed.edu/gsbs_diss/1125.

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Aging is associated with a loss of proliferation of the insulin-secreting beta cell, a possible contributing factor to the greatly increased rate of type-2 diabetes in the elderly. A landmark study from our lab previously illustrated that mild endoplasmic reticulum (ER) stress drives beta cell proliferation specifically through ATF6α, one arm of the tripartite Unfolded Protein Response (UPR). It is unknown if old beta cells differ from young beta cells in UPR signaling or proliferative response to ER stress or ATF6α activation. To investigate, young and old mouse islets were cultured ex vivo in high glucose, and beta cell proliferation was quantified by BrdU incorporation after treatment with low dose thapsigargin or activation of overexpressed ATF6α. In addition, levels of UPR signaling were compared by semi-quantitative Xbp1 splicing assay. Interestingly, although old beta cells displayed reduced proliferation in glucose compared to young beta cells, their proliferative response to low-dose thapsigargin and ATF6α activation were nearly identical, and no difference was found in Xbp1 splicing under high glucose or high ER stress conditions. These results suggest that the aged mouse beta cell does not have impaired UPR-responsive proliferation or aberrant UPR signaling when cultured ex vivo

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48

Manzello, Derek Paul. "Short and Long-term Ramifications of Climate Change upon Coral Reef Ecosystems: Case Studies Across Two Oceans." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_dissertations/78.

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World-wide coral reefs are in a state of decline as a result of many local and regional factors. Recent global mass mortalities of reef corals due to record warm sea temperatures have led researchers to consider global warming as one of the most significant threats to the persistence of coral reef ecosystems over the next 100 years. It is well established that elevated sea surface temperatures (SSTs) cause widespread coral bleaching, yet confusion lingers as to what facet of extreme temperatures is most important. Utilizing long-term in situ datasets, nine thermal stress indices were calculated and their effectiveness at segregating bleaching years a posteriori for multiple reefs on the Florida Reef Tract was tested. Simple bleaching thresholds based on deviations above the climatological maximum monthly SST were just as effective at identifying bleaching years as complex thermal stress indices. Near real-time bleaching alerts issued by NOAA's Integrated Coral Observing Network (ICON) are now based upon a running 30-day average SST, such that alerts are only issued when the running 30-day average SST exceeds the estimated bleaching threshold for a particular site. In addition to three widespread, mass-coral bleaching events, the Florida Reef Tract was impacted by three tropical storms and 12 hurricanes from 1997-2005. Sea surface cooling associated with the high frequency of hurricanes that impacted Florida in 2005 likely acted to ameliorate the severity and duration of bleaching. Nonetheless, hurricane-associated cooling is not expected to nullify the proposed effects of climate change on coral reefs. The role of thermal stress in coral bleaching has been extensively studied for eastern tropical Pacific (ETP) coral reefs. However, the ETP presents a unique opportunity as this region has sub-optimal conditions for coral reef development because of upwelling of carbon dioxide-enriched deep water along the shallow thermocline. This upwelling results in a depressed aragonite saturation state which is likely an additional factor in the poor reef development throughout the ETP. The highest aragonite saturation documented in this study occur in the Gulf of Chiriquí, which corresponds with the greatest reef development of the entire ETP. Seasonal upwelling had a significant effect on the carbonate chemistry of surface waters in Pacific Panamá. This regionally-depressed aragonite saturation state of the ETP appears to result in corals with a less dense skeleton. Density values of poritid corals from the Galápagos, where aragonite saturation was the lowest documented in this study, were significantly less dense relative to those from Panamá and the Great Barrier Reef. The density of non-living pocilloporid framework components were no different across the ETP aragonite saturation gradients. This could be a result of the activity of boring sponges removing the primary carbonate material within the dead coral skeleton, thus lowering density, albeit physical-chemical dissolution cannot be ruled out. These studies provide real-world examples of the ramifications of global climate change upon coral reef ecosystems.

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Kamuren, Zipporah T. "Alterations in indices of oxidative stress and diabetes in type I diabetic rats on a low-carbohydrate diet and pycnogenol." [Bloomington, Ind.] : Indiana University, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3204299.

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Thesis (Ph.D.)--Indiana University, Medical Sciences Program, 2006.
Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0197. Adviser: John B. Watkins, III. "Title from dissertation home page (viewed Feb. 21, 2007)."

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50

Howard, Alicia Dawn. "Indices of stress in exercising horses fed diets containing varying amounts of omega-6 and omega-3 polyunsaturated fatty acids." Texas A&M University, 2005. http://hdl.handle.net/1969.1/2517.

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Dietary omega-3 polyunsaturated fatty acids have shown substantial benefits in humans including lowered serum cholesterol, blood pressure and indices of stress. The caloric and extracaloric benefits of feeding fat supplemented diets to performance horses are well documented (Webb et al., 1987; Meyers et al., 1989; Julen et al., 1995). However, omega-3 polyunsaturated fatty acids have not been studied to any great extent. This study was conducted to determine the efficacy of feeding omega-3 fatty acids on indices of stress and serum cholesterol in horses. Nine three- and four-year old horses were assigned to diet treatments according to sex, age and athletic ability. Concentrate diets consisted of: control (A), fatsupplemented diet with corn oil (B) and fat-supplemented diet with extruded/expelled soybean oil (C; N-3). Overall, heart rates were lower in horses fed the fat-supplemented diets compared to the control diet. On reining and cutting exercise days, heart rates were lower (P<.05) in horses fed fat-supplemented diets vs. the control diet. There were no differences (P>.05) in heart rates during exercise on reining and cutting days between horses fed the two fat-supplemented diets. Recovery heart rates following the SET from the end of exercise to 60 minutes recovery (R), were significantly quicker in horses fed diet C. Plasma cortisol concentrations were lowest in horses fed the soy oil-supplemented diet and highest in horses fed the corn oil-supplemented diet. Across treatments, plasma cortisol concentrations during the SET rose due to the onset of exercise and remained significantly higher (P<.05) than baseline during the SET. Serum cholesterol concentrations were higher in horses fed corn oil-supplemented diets than in the control or the soy oil-supplemented diets. There was no significant change (P>.05) in body weight between horses consuming these three diets. However, when compared to consuming diets B and C the horses fed diet A had higher (P<.05) concentrate intakes. There was no significant difference in hay intake (P>.05) between horses consuming the three diets.

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Dissertations / Theses on the topic 'Indice de stress'

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