96 resultados para Spent catalyst


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Anthropogenic disturbance of wildlife is of growing conservation concern, but we lack comprehensive approaches of its multiple negative effects. We investigated several effects of disturbance by winter outdoor sports on free-ranging alpine Black Grouse by simultaneously measuring their physiological and behavioral responses. We experimentally flushed radio-tagged Black Grouse from their snow burrows, once a day, during several successive days, and quantified their stress hormone levels (corticosterone metabolites in feces [FCM] collected from individual snow burrows). We also measured feeding time allocation (activity budgets reconstructed from radio-emitted signals) in response to anthropogenic disturbance. Finally, we estimated the related extra energy expenditure that may be incurred: based on activity budgets, energy expenditure was modeled from measures of metabolism obtained from captive birds subjected to different ambient temperatures. The pattern of FCM excretion indicated the existence of a funneling effect as predicted by the allostatic theory of stress: initial stress hormone concentrations showed a wide inter-individual variation, which decreased during experimental flushing. Individuals with low initial pre-flushing FCM values augmented their concentration, while individuals with high initial FCM values lowered it. Experimental disturbance resulted in an extension of feeding duration during the following evening foraging bout, confirming the prediction that Black Grouse must compensate for the extra energy expenditure elicited by human disturbance. Birds with low initial baseline FCM concentrations were those that spent more time foraging. These FCM excretion and foraging patterns suggest that birds with high initial FCM concentrations might have been experiencing a situation of allostatic overload. The energetic model provides quantitative estimates of extra energy expenditure. A longer exposure to ambient temperatures outside the shelter of snow burrows, following disturbance, could increase the daily energy expenditure by >10%, depending principally on ambient temperature and duration of exposure. This study confirms the predictions of allostatic theory and, to the best of our knowledge, constitutes the first demonstration of a funneling effect. It further establishes that winter recreation activities incur costly allostatic behavioral and energetic adjustments, which call for the creation of winter refuge areas together with the implementation of visitor-steering measures for sensitive wildlife.

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Previous studies have shown that regulated firms diversify for reasons that are different than for unregulated firms. We explore some of these differences by providing a theoretical model that starts by considering the firm-regulator relationship as an incomplete information issue, in which a regulated incumbent has knowledge that the regulator does not have, but the firm cannot convey hard information about this knowledge. The incumbent faces both market and nonmarket competition from a new entrant. In that context, we show that when the firm faces tough nonmarket competition domestically, going abroad can create a mechanism that makes information transmission to the regulator more credible. International expansion can thus be a way to solve domestic nonmarket issues in addition to being a catalyst for growth.

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Since the discovery of hypocretins/orexins (Hcrt/Ox) in 1998, several narcoleptic mouse models, such as Hcrt-KO, Hcrtrl-KO, Hcrtr2-KO and double receptors KO mice, and orexin-ataxin transgenic mice were generated. The available Hcrt mouse models do not allow the dissection of the specific role of Hcrt in each target region. Dr. Anne Vassalli generated loxP-flanked alleles for each Hcrt receptor, which are manipulated by Cre recombinase to generate mouse lines with disrupted Hcrtrl or Hcrtr2 (or both) in cell type-specific manner. The role of noradrenaline (NA) and dopamine (OA) in ttie regulation of vigilance states is well documented. The purpose of this thesis is to explore the role of the Hcrt input into these two monoaminergic systems. Chronic loss of Hcrtrl in NA neurons consolidated paradoxical sleep (PS), and altered wakefulness brain activity in baseline, during the sleep deprivation (SD), and when mice were challenged by a novel environment, or exposed to nest-building material. The analysis of alterations in the sleep EEG delta power showed a consistent correlation with the changes in the preceding waking quality in these mice. Targeted inactivation of Hcrt input into DA neurons showed that Hcrtr2 inactivation present the strongest phenotype. The loss of Hcrtr2 in DA neurons caused modified brain activities in spontaneous wakefulness, during SD, and in novel environmental conditions. In addition to alteration of wakefulness quality and quantity, conditional inactivation of Hcrtr2 in DA neurons caused an increased in time spent in PS in baseline and a delayed and less complete PS recovery after SD. In the first 30 min of sleep recovery, single (i.e. for Hcrtrl or Hcrtr2) conditional knockout receptor mice had opposite changes in delta activity, including an increased power density in the fast delta range with specific inactivation of Hcrtr2, but a decreased power density in the same range with specific inactivation of Hcrtrl in DA cells. These studies demonstrate a complex impact of Hcrt receptors signaling in both NA and DA system, not only on quantity and quality of wakefulness, but also on PS amount regulation as well as on SWS delta power expression. -- Depuis la découverte des hypocrétines/orexines (Hcrt/Ox) en 1998, plusieurs modèles de souris, narcoleptiques telles que Hcrt-KO, Hcrtr2-KO et récepteurs doubles KO et les souris transgéniques orexine-ataxine ont été générés. Les modèles de souris Hcrt disponibles ne permettaient pas la dissection du rôle spécifique de l'Hcrt dans chaque noyau neuronal cible. Notre laboratoire a généré des allèles loxP pour chacun des 2 gènes codant pour les récepteurs Hcrtr, qui sont manipulés par recombinase Cre pour générer des lignées de souris avec Hcrtrl inactivé, ou Hcrtr2 inactivé, (ou les deux), spécifiquement dans un type cellulaire particulier. Le rôle de la noradrénaline (NA) et la dopamine (DA) dans la régulation des états de vigilance est bien documentée. Le but de cette thèse est d'étudier le rôle de l'afférence Hcrt dans ces deux systèmes monoaminergiques au niveau de l'activité cérébrale telle qu'elle apparaît dans l'électroencéphalogramme (EEG). Mon travail montre que la perte chronique de Hcrtrl dans les neurones NA consolide le sommeil paradoxal (PS), et l'activité cérébrale de l'éveil est modifiée en condition spontanée, au cours d'une experience de privation de sommeil (SD), et lorsque les souris sont présentées à un nouvel environnement, ou exposées à des matériaux de construction du nid. Ces modifications de l'éveil sont corrélées à des modifications de puissance de l'activité delta du sommeil lent qui le suit. L'inactivation ciblée des Hcrtrs dans les neurones DA a montré que l'inactivation Hcrtr2 conduit au phénotype le plus marqué. La perte de Hcrtr2 dans les neurones DA mène à des modification d'activité cérébrale en éveil spontané, pendant SD, ainsi que dans des conditions environnementales nouvelles. En plus de l'altération de la qualité de l'éveil et de la quantité, l'inactivation conditionnelle de Hcrtr2 dans les neurones DA a provoqué une augmentation du temps passé en sommeil paradoxal (PS) en condition de base, et une reprise retardée et moins complète du PS après SD. Dans les 30 premières minutes de la récupération de sommeil, les modèles inactivés pour un seul des récepteurs (ie pour Hcrtrl ou Hcrtr2 seulement) montrent des changements opposés en activité delta, en particulier une densité de puissance accrue dans le delta rapide avec l'inactivation spécifique de Hcrtr2, mais une densité de puissance diminuée dans cette même gamme chez les souris inactivées spécifiquement en Hcrtrl dans les neurones DA. Ces études démontrent un impact complexe de l'inactivation de la neurotransmission au niveau des récepteurs d'Hcrt dans les deux compartiments NA et DA, non seulement sur la quantité et la qualité de l'éveil, mais aussi sur la régulation de quantité de sommeil paradoxal, ainsi que sur l'expression de la puissance delta pendant le sommeil lent.

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BACKGROUND: Physical activity and sedentary behaviour in youth have been reported to vary by sex, age, weight status and country. However, supporting data are often self-reported and/or do not encompass a wide range of ages or geographical locations. This study aimed to describe objectively-measured physical activity and sedentary time patterns in youth. METHODS: The International Children's Accelerometry Database (ICAD) consists of ActiGraph accelerometer data from 20 studies in ten countries, processed using common data reduction procedures. Analyses were conducted on 27,637 participants (2.8-18.4 years) who provided at least three days of valid accelerometer data. Linear regression was used to examine associations between age, sex, weight status, country and physical activity outcomes. RESULTS: Boys were less sedentary and more active than girls at all ages. After 5 years of age there was an average cross-sectional decrease of 4.2 % in total physical activity with each additional year of age, due mainly to lower levels of light-intensity physical activity and greater time spent sedentary. Physical activity did not differ by weight status in the youngest children, but from age seven onwards, overweight/obese participants were less active than their normal weight counterparts. Physical activity varied between samples from different countries, with a 15-20 % difference between the highest and lowest countries at age 9-10 and a 26-28 % difference at age 12-13. CONCLUSIONS: Physical activity differed between samples from different countries, but the associations between demographic characteristics and physical activity were consistently observed. Further research is needed to explore environmental and sociocultural explanations for these differences.

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INTRODUCTION: With the ageing of the population and the general improvement of care, an increasing number of people are living with multiple chronic health conditions or 'multimorbidity'. Multimorbidity often implies multiple medical treatments. As a consequence, the risk of adverse events and the time spent by patients for their treatments increase exponentially. In many cases, treatment guidelines traditionally defined for single conditions are not easily applicable. Primary care for individuals with multimorbidity requires complex patient-centred care and good communication between the patient and the general practitioner (GP). This often includes prioritising among the different chronic conditions. METHODS AND ANALYSIS: The main objectives of this study are to describe the burden related to multimorbidity (disease-related burden and burden of treatment) in primary care and to identify the factors influencing it. Other objectives include evaluating patients' perception of treatment burden and quality of life, assessing factors influencing that perception, and investigating prioritisation in the management of multimorbidity from the perspectives of GPs and patients. For this cross-sectional study, patient enrolment will take place in GP's private practices across Switzerland. A convenient sample of 100 GPs will participate; overall, 1000 patients with at least three chronic health conditions will be enrolled. Data will be collected as paper-based questionnaires for GPs and delayed telephone interview questionnaires for patients. GPs will provide demographic and practice-related data. In addition, each GP will complete a paper-based questionnaire for each patient that they enrol. Each patient will complete a telephone interview questionnaire. ETHICS AND DISSEMINATION: This study has been approved by the research ethics committee of Canton Vaud, Switzerland (Protocol 315/14). The results of the study will be reported in international peer-reviewed journals.

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BACKGROUND AND AIMS: Evidence-based and reliable measures of addictive disorders are needed in general population-based assessments. One study suggested that heavy use over time (UOT) should be used instead of self-reported addiction scales (AS). This study compared UOT and AS regarding video gaming and internet use empirically, using associations with comorbid factors. DESIGN: Cross-sectional data from the 2011 French Survey on Health and Consumption on Call-up and Preparation for Defence-Day (ESCAPAD), cross-sectional data from the 2012 Swiss ado@internet.ch study and two waves of longitudinal data (2010-13) of the Swiss Longitudinal Cohort Study on Substance Use Risk Factors (C-SURF). SETTING: Three representative samples from the general population of French and Swiss adolescents and young Swiss men, aged approximately 17, 14 and 20 years, respectively. PARTICIPANTS: ESCAPAD: n =22 945 (47.4% men); ado@internet.ch: n =3049 (50% men); C-SURF: n =4813 (baseline + follow-up, 100% men). MEASUREMENTS: We assessed video gaming/internet UOT ESCAPAD and ado@internet.ch: number of hours spent online per week, C-SURF: latent score of time spent gaming/using internet] and AS (ESCAPAD: Problematic Internet Use Questionnaire, ado@internet.ch: Internet Addiction Test, C-SURF: Gaming AS). Comorbidities were assessed with health outcomes (ESCAPAD: physical health evaluation with a single item, suicidal thoughts, and appointment with a psychiatrist; ado@internet.ch: WHO-5 and somatic health problems; C-SURF: Short Form 12 (SF-12 Health Survey) and Major Depression Inventory (MDI). FINDINGS: UOT and AS were correlated moderately (ESCAPAD: r = 0.40, ado@internet.ch: r = 0.53 and C-SURF: r = 0.51). Associations of AS with comorbidity factors were higher than those of UOT in cross-sectional (AS: .005 ≤ |b| ≤ 2.500, UOT: 0.001 ≤ |b| ≤ 1.000) and longitudinal analyses (AS: 0.093 ≤ |b| ≤ 1.079, UOT: 0.020 ≤ |b| ≤ 0.329). The results were similar across gender in ESCAPAD and ado@internet.ch (men: AS: 0.006 ≤ |b| ≤ 0.211, UOT: 0.001 ≤ |b| ≤ 0.061; women: AS: 0.004 ≤ |b| ≤ 0.155, UOT: 0.001 ≤ |b| ≤ 0.094). CONCLUSIONS: The measurement of heavy use over time captures part of addictive video gaming/internet use without overlapping to a large extent with the results of measuring by self-reported addiction scales (AS). Measuring addictive video gaming/internet use via self-reported addiction scales relates more strongly to comorbidity factors than heavy use over time.