964 resultados para spray irrigation
Resumo:
CD66b is a member of the carcinoembryonic antigen family, which mediates the adhesion between neutrophils and to endothelial cells. Allergen-specific immunotherapy is widely used to treat allergic diseases, and the molecular mechanisms underlying this therapy are poorly understood. The present work was undertaken to analyze A) the in vitro effect of allergens and immunotherapy on cell-surface CD66b expression of neutrophils from patients with allergic asthma and rhinitis and B) the in vivo effect of immunotherapy on cell-surface CD66b expression of neutrophils from nasal lavage fluid during the spring season. Myeloperoxidase expression and activity was also analyzed in nasal lavage fluid as a general marker of neutrophil activation. RESULTS CD66b cell-surface expression is upregulated in vitro in response to allergens, and significantly reduced by immunotherapy (p<0.001). Myeloperoxidase activity in nasal lavage fluid was also significantly reduced by immunotherapy, as were the neutrophil cell-surface expression of CD66b and myeloperoxidase (p<0.001). Interestingly, CD66b expression was higher in neutrophils from nasal lavage fluid than those from peripheral blood, and immunotherapy reduced the number of CD66+MPO+ cells in nasal lavage fluid. Thus, immunotherapy positive effects might, at least in part, be mediated by the negative regulation of the CD66b and myeloperoxidase activity in human neutrophils.
Resumo:
La station touristique représente un espace urbain consacré principalement au tourisme, tout en comprenant également une population résidente permanente. Du point de vue de la gestion des réseaux urbains de l'eau, cette caractéristique induit pour ce type de lieu des usages propres à tout espace urbain mais également des spécificités liées à la forte fluctuation saisonnière de la population résidente ou encore à la présence d'usages particuliers tels que l'irrigation des golfs, la production de neige artificielle ou le thermalisme. Dès lors, la planification de l'approvisionnement est délicate et peu prévisible. Ces difficultés sont renforcées par le fait que les concentrations temporelles de la demande coïncident généralement avec des périodes de stress hydrique notable. Dans le cas de stations balnéaires, les pics de fréquentation interviennent en général durant l'été lorsque la ressource en eau est peu disponible. Le problème est similaire dans les stations touristiques de montagne où l'eau est généralement indisponible car stockée sous forme de neige durant les mois de forte fréquentation. De plus, ces difficultés sont souvent renforcées par la localisation géographique des stations touristiques, fréquemment situées dans des espaces sensibles du point de vue de la ressource en eau, avec des situations de pénuries temporelles, voire structurelles. Ces problématiques propres à la plupart des stations touristiques mènent souvent à de fortes rivalités entre, d'une part, les différents usages touristiques de la ressource, et d'autre part, les usages autochtones et touristiques. Les particularités liées au tourisme tendent ainsi à renforcer les rivalités entre différents types de secteurs d'activité (approvisionnement en eau potable, tourisme, hydroélectricité, enneigement artificiel, irrigation, etc.). Ces différents usages de la ressource mis en concurrence nécessitent dès lors la mise en oeuvre de réglementations structurées à travers des politiques publiques ainsi que des droits de propriété et selon des composantes nationales, régionales et locales ; soit un cadre institutionnel que nous proposons d'appeler Régime Institutionnel de Ressource (RIR) (Knoepfel et al. 2001, 2007). A travers cette thèse de doctorat, nous répondons à différentes questions de recherche. Nous tentons d'abord de comprendre comment ces différents RIR sont-ils mis en oeuvre dans le cadre d'espaces touristiques ? Comment ceux-ci sont-ils concrétisés par les acteurs et quels sont leurs effets en termes de durabilité technique, environnementale, sociale et économique des réseaux urbains de l'eau ? Nous questionnons ensuite les effets du tourisme sur la gestion des infrastructures de réseau à l'échelle de la station touristique et de son bassin versant et nous interrogeons sur les effets du tourisme en termes de gestion des eaux urbaines. Nous portons notre attention sur deux stations touristiques situées dans deux contextes institutionnels différents (Crans-Montana en Suisse et Morzine-Avoriaz en France) et y étudions trois types de régimes institutionnels en particulier : la régie directe (gestion publique), l'affermage (gestion déléguée) et la gestion privée des infrastructures. Les résultats de cette thèse de doctorat indiquent tout d'abord dans quelle mesure le tourisme modifie de façon significative la perception et les modalités de gestion de la ressource en eau et des infrastructures. Ils montrent ensuite que l'espace fonctionnel de la gestion de ces infrastructures correspond rarement aux limites du réseau hydrographique naturel et quelles en sont les implications en termes de durabilité. Enfin, la comparaison de différents régimes institutionnels révèle les forces et les faiblesses de chaque modèle de gestion dans le cas spécifique des stations touristiques et également les différentes solutions adoptées localement pour la mise en oeuvre d'un arrangement institutionnel permettant un usage plus ou moins durable des infrastructures de réseau et du réseau hydrographique naturel. - Tourism resort represents an urban area mainly dedicated to tourism while including at the same time a permanent residential population. From the point of view of urban water networks, this characteristic induces a strong seasonal fluctuation of residential population and involves special water uses such as golf irrigation, production of artificial snow or functioning of thermal baths. Therefore, water supply planning can be tricky and difficult to predict. These difficulties are reinforced by the fact that temporary concentrations of water demand coïncidé generally with periods of water stress. In the case of seaside resorts, frequenting peaks arise in general during summer when water resource is less available. The problem is similar in mountainous tourist resorts where water is generally unavailable as it is stored as snow during months of highest frequenting. Furthermore, these difficulties are often reinforced by resorts' geographical localisations, which are often situated in sensitive areas in terms of temporary or structural water shortages. These problematic issues often lead to strong rivalries between tourists' water uses on the one hand, and between locals and tourists uses on the other hand. Thus, features of tourism tend to reinforce rivalries between different sectors of activity (supply of drinking water, tourism, hydroelectricity, artificial snow, irrigation, etc.). These different and competing water uses need the implementation of rules structured through public policies and property rights and through national, regional and local legal components; We propose to call this framework as an Institutional Resource Regime (IRR) (Knoepfel et al. 2001, 2007, 2009). Through this PhD thesis, we answer different research questions. We firstly aim to understand how those different IRR are implemented within tourism spaces? How do actors materialize them and what are their effects in term of technical, environmental, social and economical sustainability of urban water networks? We then, investigate effects of tourism on water networks infrastructures' management at the scale of the tourist resort and its river basin. We focus our attention on two tourist resorts situated within two different institutional contexts (Crans-Montana, Switzerland and Morzine-Avoriaz, France) and study three types of institutional regime in particular: public, delegated and private management of infrastructures. Results of this PhD thesis indicate firstly how tourism modifies in a significant way the perception and management modalities of water resource and infrastructures. Results also show that functional space of infrastructures management rarely matches with the limits of the natural river basin and indicates what it means in terms of sustainability. Finally, the comparison of different institutional regimes reveals the strengths and weakness of each management model in the specific case of tourist resorts and shows the different solutions in locally implementing an institutional arrangement for a more or less sustainable management of network infrastructures and natural water system.
Resumo:
BACKGROUND: Nicotine dependence is the major obstacle for smokers who want to quit. Guidelines have identified five effective first-line therapies, four nicotine replacement therapies (NRTs)--gum, patch, nasal spray and inhaler--and bupropion. Studying the extent to which these various treatments are cost-effective requires additional research. OBJECTIVES: To determine cost-effectiveness (CE) ratios of pharmacotherapies for nicotine dependence provided by general practitioners (GPs) during routine visits as an adjunct to cessation counselling. METHODS: We used a Markov model to generate two cohorts of one-pack-a-day smokers: (1) the reference cohort received only cessation counselling from a GP during routine office visits; (2) the second cohort received the same counselling plus an offer to use a pharmacological treatment to help them quit smoking. The effectiveness of adjunctive therapy was expressed in terms of the resultant differential in mortality rate between the two cohorts. Data on the effectiveness of therapies came from meta-analyses, and we used odds ratio for quitting as the measure of effectiveness. The costs of pharmacotherapies were based on the cost of the additional time spent by GPs offering, prescribing and following-up treatment, and on the retail prices of the therapies. We used the third-party-payer perspective. Results are expressed as the incremental cost per life-year saved. RESULTS: The cost per life-year saved for only counselling ranged from Euro 385 to Euro 622 for men and from Euro 468 to Euro 796 for women. The CE ratios for the five pharmacological treatments varied from Euro 1768 to Euro 6879 for men, and from Euro 2146 to Euro 8799 for women. Significant variations in CE ratios among the five treatments were primarily due to differences in retail prices. The most cost-effective treatments were bupropion and the patch, and, then, in descending order, the spray, the inhaler and, lastly, gum. Differences in CE between men and women across treatments were due to the shape of their respective mortality curve. The lowest CE ratio in men was for the 45- to 49-year-old group and for women in the 50- to 54-year-old group. Sensitivity analysis showed that changes in treatment efficacy produced effects only for less-well proven treatments (spray, inhaler, and bupropion) and revealed a strong influence of the discount rate and natural quit rate on the CE of pharmacological treatments. CONCLUSION: The CE of first-line treatments for nicotine dependence varied widely with age and sex and was sensitive to the assumption for the natural quit rate. Bupropion and the nicotine patch were the two most cost-effective treatments.
Resumo:
We present the study of the geochemical processes associated with the first successful remediation of a marine shore tailings deposit in a coastal desert environment (Bahia de Ite, in the Atacama Desert of Peru). The remediation approach implemented a wetland on top of the oxidized tailings. The site is characterized by a high hydrauliz gradient produced by agricultural irrigation on upstream gravel terraces that pushed river water (similar to 500 mg/L SO(4)) toward the sea and through the tailings deposit. The geochemical and isotopic (delta(2)H(water) and delta(18)O(water), delta(34)S(sulfate) , delta(18)O(sulfate)) approach applied here revealed that evaporite horizons (anhydrite and halite) in the gravel terraces are the source of increased concentrations of SO(4), Cl, and Na up to similar to 1500 mg/L in the springs at the base of the gravel terraces. Deeper groundwater interacting with underlying marine sequences increased the concentrations of SO(4), Cl, and Na up to 6000 mg/L and increased the alkalinity up to 923 mg/L CaCO(3) eq. in the coastal aquifer. These waters infiltrated into the tailings deposit at the shelf-tailings interface. Nonremediated tailings had a low-pH oxidation zone (pH 1-4) with significant accumulations of efflorescent salts (10-20 cm thick) at the surface because of upward capillary transport of metal cations in the arid climate. Remediated tailings were characterized by neutral pH and reducing conditions (pH similar to 7, Eh similar to 100 mV). As a result, most bivalent metals such as Cu, Zn, and Ni had very low concentrations (around 0.01 mg/L or below detection limit) because of reduction and sorption processes. In contrast, these reducing conditions increased the mobility of iron from two sources in this system: (1) The originally Fe(III)-rich oxidation zone, where Fe(II) was reduced during the remediation process and formed an Fe(II) plume, and (2) reductive dissolution of Fe(III) oxides present in the original shelf lithology formed an Fe-Mn plume at 10-m depth. These two Fe-rich plumes were pushed toward the shoreline where more oxidizing and higher pH conditions triggered the precipitation of Fe(HI)hydroxide coatings on silicates. These coatings acted as a filter for the arsenic, which naturally infiltrated with the river water (similar to 500 mu g/L As natural background) into the tailings deposit.