989 resultados para Second-hand smoke
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Epidemiological studies have demonstrated that exposure to fine particles is associated to adverse health effects, including cancer, respiratory and cardiovascular diseases. However, mechanisms by which particles induce health effects remain unclear. According to one of the most investigated hypotheses, particles cause adverse effects through the production of reactive oxygen species (ROS), which are very hazardous compounds able to attack directly biological structures, including the DNA strand or the lipid bilayer of the cells. If the defense mechanisms, constituted of antioxidants, are not able to counter ROS, then these compounds will cause in the body a range of oxidation reactions called "oxidative stress". The aim of the present research project was to better understand mechanisms by which exposure to fine particles induces oxidative stress. The first point of this project was to check whether exposure to high levels of fine particles is directly linked to oxidative stress, and whether this oxidative stress is accompanied by the activation of the defense mechanisms (antioxidants). The second point was to study the role played by the particle surface characteristics in the oxidative stress process. For that purpose, a study was conducted in bus depots with the participation of 40 mechanics. First, occupational exposure to particles (PM4) and to other pollutants (NOx, O3) was measured over a two-day period. Then, urine samples of mechanics were collected in order to measure levels of 8-hydroxy-2'-deoxyguanosine (8OHdG) and antioxidants. 8OHdG is a molecule formed by the oxidation of DNA and allowing to assess the oxidative stress status of the mechanics. Finally, particles were collected on filters, and functional groups located on the particle surface were analyzed in the laboratory using a Knudsen flow reactor. This technique allows not only to quantify functional groups on the particle surface, but also to measure the reaction kinetics. Results obtained during the field campaign in bus depots showed that mechanics were exposed to rather low levels of PM4 (20-85 μg/m3) and of pollutants (NOx: 100-1000 ppb; O3: <15 ppb). However, despite this low exposure, urinary levels of the oxidative stress biomarker (8OHdG) increased significantly for non-smoking workers over a two-day period of shift. This oxidative stress was accompanied by an increase of antioxidants, indicating the activation of defense mechanisms. On the other hand, the analysis of functional groups on the particle surface showed important differences, depending on the workplace, the date and the activities of workers. The particle surface contained simultaneously antagonistic functional groups which did not undergo internal reactions (such as acids and bases), and was usually characterized by a high density of carbonyl functions and a low density of acidic sites. Reaction kinetics measured using the Knudsen flow reactor pointed out fast reactions of oxidizable groups and slow reactions of acidic sites. Several exposure parameters were significantly correlated with the increase of the oxidative stress status: the presence of acidic sites, carbonyl functions and oxidizable groups on the particle surface; reaction kinetics of functional groups on the particle surface; particulate iron and copper concentrations; and NOx concentration.
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Référence bibliographique : Rol, 57057
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Report for Iowa Utilities Board
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Résumé en français: L'hyperémie réactive dans la microcirculation musculature et cutanée de l'avant-bras permet d'évaluer l'atteinte vasculaire dans les maladie cardiovasculaires. Cette méthode permet d'obtenir un reflet de la progression de l'atteinte vasculaire, de traquer la progression de la maladie ainsi que le risque cardio-vasculaires. Elle est en étude également pour tester l'efficacité d'une intervention thérapeutique. L'hyperémie réactive est dépendante d'une dilatation post ischémique par diminution des résistances artériolaires. Au niveau des membres, l'ischémie peut-être débutée et interrompue très facilement par une manchette à pression gonflée au-dessus de la pression systolique suivie quelques minutes plus tard de son dégonflement. Les mesures de flux sanguin musculaire et cutané au niveau d'un membre sont facile à réaliser chez l'homme, tout particulièrement au niveau de l'avant-bras. Pour l'instant aucune étude utilisant cette approche ne spécifiait quel avant-bras était utilisé. Il est cependant concevable que la réponse varie selon que l'on teste le bras dominant ou non-dominant. Il parait donc important de clarifier ce point. Le premier but de l'étude consiste donc à investiguer une éventuelle différence entre le bras dominant et le bras non-dominant d'un sujet lors de tests de l'hyperémie réactive dans le muscle et la peau. Il est connu que l'hyperémie réactive au niveau musculaire peut-être diminuée par les médicaments antiinflammatoires non stéro~idiens (AINS), indiquant une implication partielle des métabolites de la cyclo-oxygénase. L'influence des AINS sur la réponse cutanée est moins clairement établie. Ainsi, le second but de cette étude est de comparer l'effet de l'inhibition de la cyclo-oxygénase sur l'hyperémie réactive musculaire et cutanée chez des sujets sains. Le collectif de patients consiste en 23 sujets masculins volontaires, en bonne santé, non fumeurs, de 18 à 30 ans. Aucuns antécédents médicaux ne sont connus et aucune médication n'est prise durant la période de l'étude. Tous . les sujets ont donné leur consentement par écrit. Le flux sanguin musculaire de l'avant-bras est mesuré au moyen d'une pléthysmographie par occlusion veineuse, et le flux cutané l'est par imagerie laser Doppler. Les expériences ont lieu entre 16 et 18 h dans une chambre calme à température constante (23-24°C) chez un sujet couché. Les participants n'ont pas consommé d'AINS durant la semaine précédente ni bu de café dans les 12 h précédant l'expérience. Les mesures sont effectuées en triplicat au niveau musculaire puis cutané ou inversement selon un ordre aléatoire. Suite à une occlusion artérielle l'étude du flux se fait sur 3 min et 5 min de récupération sont prises entre 2 mesures. L'expérience 1 consiste à tester un possible effet systématique de la latéralisation du bras dominant ou non sur la réponse à l'hyperémie réactive dans la peau et le muscle de l'avant-bras. 16 sujets sont étudiés à 2 reprises, espacées de 1 à 3 jours. A la première visite, l'hyperémie musculaire est étudiée dans un avant-bras, la réaction cutanée dans l'autre et inversement lors de la deuxième visite. Une précaution est observée afin de mesurer le flux sanguin cutané à la même distance du poignet dans les 2 avant-bras. L'expérience 2 est développée pour évaluer l'impact d'une inhibition des cyclo-oxygénases. Sept sujet sont considérés à 2 occasions espacées de 7 à 10 j. L'étude s'effectue uniquement au niveau de l'avant-bras dominant. Le site cutané au niveau du poignet est marqué lors de la première visite afin d'utiliser le même site de mesure lors de la seconde visite. Le sujet ingère 1,8 g d'Aspegic (équivalant à 1 g d'acide acétylsalilcylique) dissout dans 125 ml de jus d'orange ou le jus d'orange seul lors de l'autre visite selon un ordre randomisé. Les mesures sont débutées 2 h après la prise. Summary Reactive hyperemia (RH) in forearm muscle or skin microcirculation has been considered as a surrogate endpoint in clinical studies of cardiovascular disease. We evaluated two potential confounders that might limit such use of RH, namely laterality of measurement and intake of non-steroidal anti-inflammatory drugs (NSAIDS). Twenty-three young non-smoking healthy adults were enrolled. In Experiment 1 (n=16), the RH elicited by 3 min of ischemia was recorded in the muscle (strain gauge plethysmography, hand excluded) and skin (laser Doppler imaging) of both forearms. In Experiment 2 (n=7), RH was determined in the dominant forearm only, one hour following oral acetylsalicylic acid (1 g) or placebo. In Experiment 1, peak RH was identical in both forearms, and so were the corresponding durations of responses. RH lasted significantly less in muscle than in skin (p=0.003), a hitherto unrecognized fact. In the skin, acetylsalicylate reduced duration (43 vs 57.4 s for placebo, p=0.03), without affecting the peak response. In muscle, duration tended to decrease with acetylsalicylate (21.4 vs 26.0 s with placebo, p=0.06) and the peak increase in blood flow was blunted (27.2 vs 32.4 ml/min/100 ml tissue with placebo, p=0.003). We conclude that, when using RH as a surrogate endpoint in studies of cardiovascular disease, a confounding by laterality of measurement need not be feared, but NSAIDS may have an influence, although perhaps not on the peak response in the skin.
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Qui sait qu'en Suisse, les associations patronales mettent en oeuvre l'Etat social ? Qui sait que associations organisent la majorité des caisses de compensation, dont la fonction principale est de collecter les cotisations et de payer les rentes de l'Assurance-vieillesse et survivants ? Qui connaît ces caisses par lesquelles transitent les milliards de l'Etat social ? L'objectif de cette thèse consiste à comprendre les raisons qui ont poussé le patronat helvétique à mettre en oeuvre les politiques de protection sociale, dont il a pourtant toujours essayé de limiter le développement. Résoudre ce paradoxe implique de se pencher sur près d'un siècle d'histoire mêlée du patronat et des politiques sociales. Ce travail retrace, sur la base d'archives privées et publiques souvent inédites, les raisons qui ont poussé les patrons à créer les premières caisses de compensation dans l'entre-deux-guerres, puis à imposer cette forme d'organisation pour l'aide aux soldats mobilisés (autour de 1940) et l'Assurance- vieillesse et survivants (autour de 1948). Il étudie également comment les associations patronales sont parvenues à défendre leurs caisses jusqu'à aujourd'hui, contre ceux qui dénonçaient l'irrationalité de l'existence d'une centaine de caisses de compensation publiques et privées concurrentes pour mettre en oeuvre un seul système d'assurances sociales. Cette recherche amène deux grands résultats. D'une part, elle propose une histoire originale des politiques sociales en Suisse. Le prisme des caisses de compensation patronales contribue en effet à interroger notre compréhension de l'histoire des politiques de protection sociale, dans laquelle on sous-estime parfois l'importance des conflits pour fixer les frontières entre formes de protection publique et privée. D'autre part, ce travail présente une histoire inédite de l'action collective des patrons dans les régulations du travail au sens large. A travers les caisses de compensation, c'est en effet à réaliser une histoire de l'Union centrale des associations patronales suisses que je me suis aussi attelé. Faute de parvenir à empêcher tout développement des politiques sociales, les patrons ont fait en sorte d'acquérir sur ces politiques une forme de mainmise. Entre histoire des politiques sociales et histoire du patronat, ce travail tente d'expliquer comment les caisses de compensation y ont contribué. Who knows that, in Switzerland, employers' associations implement the best known policies constituting the welfare state? Who knows that the equalization funds, (Caisses de compensation / Ausgleichskassen), organized by employers' associations or by the Swiss Cantons, are responsible for pooling payroll deductions and for paying benefits of the Swiss public pay-as-you-go, old-age insurance and many other branches of the welfare policies? Who knows these caisses de compensation that channel the monies dedicated to the financing of the Welfare state ? The main objective of this research is to understand the reasons why Swiss employers do implement such welfare policies that they usually reject for political reasons. In order to solve this puzzle, this research investigates half of a century of the connected histories of welfare policies and employers' collective action. It also investigates, based on public and private archive records, how employers founded the first caisses in the Interwar period, and imposed them to organize the main developments of the Welfare state during the Second World War. The research also underlines how employers defended their caisses de compensation against those questioning the rationality of this fragmented system aiming to implement one single set of public welfare through one hundred competing private and public caisses de compensation. This research highlights two main results. On the one hand, it helps to improve our understanding of the history of the welfare policies in Switzerland. Underlining the role of the caisses de compensation helps to highlight the importance of the interplay of public and private actors regarding social polices. On the other hand, this research charts a pioneering history of Swiss' employers' collective action regarding labor issues. Because they could not prevent all public welfare policy, employers achieved a form of stranglehold (mainmise) on the welfare State. Halfway between social policy and employers' associations' history, this research try to reveal how their caisses de compensation helped them in this objective.
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L’estudi examina les relacions entre (1) les xarxes socials personals de la població immigrant resident a Barcelona i (2) les seves identitats culturals múltiples. L’objectiu principal de l’estudi és entendre com el contingut i l’estructura de les relacions socials dels immigrants facilita o dificulta (1) tenir un sentiment de pertinença a les noves cultures d’acollida, la catalana i la espanyola, i (2) la integració d’aquestes noves identitats socioculturals amb la seva identitat d’origen en una nova identitat bicultural cohesiva. El nostre plantejament inicial era que els immigrants amb xarxes socials més diverses des del punt de vista de la seva composició cultural tindrien més recursos socials i experiències cognitives més diverses , factors que afavoreixen les identificacions múltiples i la participació cívica. Els resultats de l’estudi mostren que el grau d’identificació dels participants amb la seva cultura ètnica o d’origen és força alt i, en certa mesura, més alt en comparació amb les cultures d’acollida ( catalana, cívica i espanyola). Tanmateix, el vincle dels participants amb les cultures d’acollida (p. ex., la cultura catalana) és prou rellevant per a indicar una orientació bicultural (catalana i ètnica). Les anàlisis de correlacions revelen que sentir-se català no impedeix sentir-se part de la comunitat etnocultural d’origen. A més, existeix una interrelació entre l'orientació cultural catalana i la identificació amb les comunitats cíviques locals. De la mateixa manera, tenir competències en llengua catalana no va en detriment de les competències en llengua castellana. Les anàlisis també mostren que factors com l’orientació cultural catalana, l’ús del català i la identificació amb la cultura catalana tenen una correlació positiva amb el grau de chohesio de la indentitat bicultural, afavoreixen el benestar psicològic i disminueixen l’estrès aculturatiu. L’anàlisi de les xarxes socials mostra que la identificació amb la cultura catalana, l’orientació cultural catalana i la integració de la identitat són factors clau per tenir xarxes socials més diverses des del punt de vista ètnic i lingüístic, amb menys membres del col•lectiu d’origen, i amb subgrups o “cliques” culturalment més heterogenis. La identificació espanyola també prediu, en mesura més reduïda, la diversitat de les xarxes. Els nostres resultats contribueixen a la recerca actual i les teories sobre interculturalitat i identitat cultural.
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Restricted Hartree-Fock 6-31G calculations of electrical and mechanical anharmonicity contributions to the longitudinal vibrational second hyperpolarizability have been carried out for eight homologous series of conjugated oligomers - polyacetylene, polyyne, polydiacetylene, polybutatriene, polycumulene, polysilane, polymethineimine, and polypyrrole. To draw conclusions about the limiting infinite polymer behavior, chains containing up to 12 heavy atoms along the conjugated backbone were considered. In general, the vibrational hyperpolarizabilities are substantial in comparison with their static electronic counterparts for the dc-Kerr and degenerate four-wave mixing processes (as well as for static fields) but not for electric field-induced second harmonic generation or third harmonic generation. Anharmonicity terms due to nuclear relaxation are important for the dc-Kerr effect (and for the static hyperpolarizability) in the σ-conjugated polymer, polysilane, as well as the nonplanar π systems polymethineimine and polypyrrole. Restricting polypyrrole to be planar, as it is in the crystal phase, causes these anharmonic terms to become negligible. When the same restriction is applied to polymethineimine the effect is reduced but remains quantitatively significant due to the first-order contribution. We conclude that anharmonicity associated with nuclear relaxation can be ignored, for semiquantitative purposes, in planar π-conjugated polymers. The role of zero-point vibrational averaging remains to be evaluated
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We present a method for analyzing the curvature (second derivatives) of the conical intersection hyperline at an optimized critical point. Our method uses the projected Hessians of the degenerate states after elimination of the two branching space coordinates, and is equivalent to a frequency calculation on a single Born-Oppenheimer potential-energy surface. Based on the projected Hessians, we develop an equation for the energy as a function of a set of curvilinear coordinates where the degeneracy is preserved to second order (i.e., the conical intersection hyperline). The curvature of the potential-energy surface in these coordinates is the curvature of the conical intersection hyperline itself, and thus determines whether one has a minimum or saddle point on the hyperline. The equation used to classify optimized conical intersection points depends in a simple way on the first- and second-order degeneracy splittings calculated at these points. As an example, for fulvene, we show that the two optimized conical intersection points of C2v symmetry are saddle points on the intersection hyperline. Accordingly, there are further intersection points of lower energy, and one of C2 symmetry - presented here for the first time - is found to be the global minimum in the intersection space
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The basis set superposition error-free second-order MØller-Plesset perturbation theory of intermolecular interactions was studied. The difficulties of the counterpoise (CP) correction in open-shell systems were also discussed. The calculations were performed by a program which was used for testing the new variants of the theory. It was shown that the CP correction for the diabatic surfaces should be preferred to the adiabatic ones
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BACKGROUND:: Although cell therapy is a promising approach after cerebral cortex lesion, few studies assess quantitatively its behavioral gain in non-human primates. Furthermore, implantations of fetal grafts of exogenous stem cells are limited by safety and ethical issues. OBJECTIVE:: To test in non-human primates the transplantation of autologous adult neural progenitor cortical cells with assessment of functional outcome. METHODS:: Seven adult macaque monkeys were trained to perform a manual dexterity task, before the hand representation in motor cortex was chemically lesioned unilaterally. Five monkeys were used as control, compared to two monkeys subjected to different autologous cells transplantation protocols performed at different time intervals. RESULTS:: After lesion, there was a complete loss of manual dexterity in the contralesional hand. The five "control" monkeys recovered progressively and spontaneously part of their manual dexterity, reaching a unique and definitive plateau of recovery, ranging from 38% to 98% of pre-lesion score after 10 to 120 days. The two "treated" monkeys reached a first spontaneous recovery plateau at about 25 and 40 days post-lesion, representing 35% and 61% of the pre-lesion performance, respectively. In contrast to the controls, a second recovery plateau took place 2-3 months after cell transplantation, corresponding to an additional enhancement of functional recovery, representing 24 and 37% improvement, respectively. CONCLUSIONS:: These pilot data, derived from two monkeys treated differently, suggest that, in the present experimental conditions, autologous adult brain progenitor cell transplantation in non-human primate is safe and promotes enhancement of functional recovery.
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A passive sampling device called Monitor of NICotine or "MoNIC", was constructed and evaluated by IST laboratory for determining nicotine in Environmental Tobacco Smoke (ETS). Vapour nicotine was passively collected on a potassium bisulfate treated glass fibre filter as collection medium. Analysis of amount of nicotine on the treated filter by gas chromatography equipped with Thermoionic-Specific Detector (GCTSD) after liquid-liquid extraction of 1mL of 5N NaOH : 1 mL of n-heptane saturated with NH3 using quinoline as internal standard. Based on nicotine amount of 0.2 mg/cigarette as reference, the inhaled Cigarette Equivalents (CE) by non-smokers can be calculated. Using the detected CE on the badge for nonsmokers, and comparing with amount of nicotine and cotinine level in saliva of both smokers and exposed non-smokers (N=49), we can confirm the use of the CE concept for estimating exposure to ETS. The Valais CIPRET (Center of information and prevention of the addiction to smoking), is going to organize a big campaign on the subject of the passive addiction to smoking entitled "Smoked passive, we suffer from it, we die from it ". This campaign will take place in 2007 and has for objective to inform clearly the population of Valais of the dangerousness of the passive smoke. More than 1'500 MoNIC badges were gracefully distributed to Swiss population to perform a self-monitoring of population exposure level to ETS, expressed in term of CE. Non-stimulated saliva were also collected to determine ETS biomarkers nicotine/cotinine levels of participating volunteers. Preliminary results of different levels of CE in occupational and non-occupational situations in relation with ETS were presented in this study.
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Study report on highways, roads and streets for future years by Iowa Department of Transportation
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Estudi realitzat a partir d’una estada a la University of Oxford, Gran Bretanya, entre 2010 i 2012. Durant l’estada postdoctoral a la University of Oxford s’han efectuat dos estudis relacionats amb l’onomàstica dels faraons d’Egipte i que constitueixen una continuació de l’anàlisi de la titulatura d’Alexandre el Gran realitzada prèviament per l’investigador en la seva recerca doctoral. El primer estudi examina la titulatura faraònica dels emperadors romans en comparació amb la d’Alexandre i, en especial, la significació ideològica i política dels paral•lelismes onomàstics existents entre elles, els quals han estat analitzats en el marc de la imitatio-aemulatio-comparatio Alexandri. Per al cas d’August, s’ha arribat a la conclusió que l’adopció de determinats apel•latius egipcis utilitzats anteriorment per Alexandre pot ser interpretada com un exemple local o estrictament egipci d’imitatio Alexandri, mentre que, en relació amb la resta d’emperadors, atès que les seves titulatures faraòniques es basen o imiten la del primer emperador, aquestes represes han de ser vistes més aviat com un exemple d’imitatio (o comparatio) Augusti. El segon estudi versa sobre la titulatura faraònica egípcia i la tradició annalística. A partir d’una anàlisi comparativa dels protocols onomàstics dels fundadores de cadascuna de les dinasties, s’ha intentat determinar si determinats noms o epítets s’empren de forma recurrent i d’una manera deliberada per tal de senyalar canvis dinàstics, és a dir, noves realitats polítiques. En concret, s’ha pretès establir fins a quin punt determinats recursos onomàstics tenen el seu reflex en la divisió en dinasties de Manetó i, alhora, determinar en quina mesura l’estudi de l’onomàstica faraònica pot contribuir al coneixement de com els egipcis conceptualitzaren i organitzaren el seu propi passat.