953 resultados para Microcirculation - Theses


Relevância:

10.00% 10.00%

Publicador:

Resumo:

DIC.CAT es centra en les contribucions a la ciutadania que realitzen les dones immigrants marroquines, sobre les quals recauen forts estereotips i imatges que, sovint, les vinculen a la passivitat i a la submissió. Partint d'aquest fet, el projecte analitza el paper d'aquetes dones com a generadores de noves formes de ciutadania a Catalunya, a partir de les seves accions en les esferes pública i privada. El projecte contribueix, d'una banda a ampliar el coneixement teòric sobre la noció de ciutadania, incorporant la dimensió del gènere i partint de la realitat multicultural actual; i de l'altra a aprofundir sobre el rol que estan exercint les doens marroquines estudiades, com agents actius de xsocialització i generadores de canvis en els formes d'exercir la ciutadania en la societat catalana. Destaquen les accions que desenvolupen des de la seva quotidianitat en relació a aspectes com el procés de reagrupació, la incorporació al mercat laboral, la transmissio de valores dins la familia, la relació amb la comunitat d'origen, les motivacions, aspiracions o els projectes professionals i personals propis. Alhora, el projecte vincula aquestes accions amb les que desenvolupen des dels espais públics en els que participen, especialment dins l'àmbit associatiu.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The quality of the time dedicated to child care has potential positive effects on children’s life chances. However, the determinants of parental time allocation to child care remain largely unexplored, particularly in context undergoing rapid family change such as Spain. We assess two alternative explanations for differences between parents in the amount of time spent with children. The first, based in the relative resources hypothesis, links variation in time spent with children to the relative attributes (occupation, education or income) of one partner to the other. The second, derived from the social status hypothesis, suggests that variation in time spent with children is attributable to the relative social position of the pair (i.e. higher status couples spend more time with children regardless of within-couple difference).To investigate theses questions, we use a sample of adults (18-50) from the Spanish Time Use Survey (STUS) 2002-2003 (n=7,438). Limiting the analysis to adults who are married or in consensual unions, the STUS allows to assess both the quantity and quality of parental time spent with children. We find little support for the “relative resources hypothesis”. Instead, consistent with the “social status hypothesis”, we find that time spent on child care is attributable to the social position of the couple, regardless of between-parent differences in income of education.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Particle physics studies highly complex processes which cannot be directly observed. Scientific realism claims that we are nevertheless warranted in believing that these processes really occur and that the objects involved in them really exist. This dissertation defends a version of scientific realism, called causal realism, in the context of particle physics. I start by introducing the central theses and arguments in the recent philosophical debate on scientific realism (chapter 1), with a special focus on an important presupposition of the debate, namely common sense realism. Chapter 2 then discusses entity realism, which introduces a crucial element into the debate by emphasizing the importance of experiments in defending scientific realism. Most of the chapter is concerned with Ian Hacking's position, but I also argue that Nancy Cartwright's version of entity realism is ultimately preferable as a basis for further development. In chapter 3,1 take a step back and consider the question whether the realism debate is worth pursuing at all. Arthur Fine has given a negative answer to that question, proposing his natural ontologica! attitude as an alternative to both realism and antirealism. I argue that the debate (in particular the realist side of it) is in fact less vicious than Fine presents it. The second part of my work (chapters 4-6) develops, illustrates and defends causal realism. The key idea is that inference to the best explanation is reliable in some cases, but not in others. Chapter 4 characterizes the difference between these two kinds of cases in terms of three criteria which distinguish causal from theoretical warrant. In order to flesh out this distinction, chapter 5 then applies it to a concrete case from the history of particle physics, the discovery of the neutrino. This case study shows that the distinction between causal and theoretical warrant is crucial for understanding what it means to "directly detect" a new particle. But the distinction is also an effective tool against what I take to be the presently most powerful objection to scientific realism: Kyle Stanford's argument from unconceived alternatives. I respond to this argument in chapter 6, and I illustrate my response with a discussion of Jean Perrin's experimental work concerning the atomic hypothesis. In the final part of the dissertation, I turn to the specific challenges posed to realism by quantum theories. One of these challenges comes from the experimental violations of Bell's inequalities, which indicate a failure of locality in the quantum domain. I show in chapter 7 how causal realism can further our understanding of quantum non-locality by taking account of some recent experimental results. Another challenge to realism in quantum mechanics comes from delayed-choice experiments, which seem to imply that certain aspects of what happens in an experiment can be influenced by later choices of the experimenter. Chapter 8 analyzes these experiments and argues that they do not warrant the antirealist conclusions which some commentators draw from them. It pays particular attention to the case of delayed-choice entanglement swapping and the corresponding question whether entanglement is a real physical relation. In chapter 9,1 finally address relativistic quantum theories. It is often claimed that these theories are incompatible with a particle ontology, and this calls into question causal realism's commitment to localizable and countable entities. I defend the commitments of causal realism against these objections, and I conclude with some remarks connecting the interpretation of quantum field theory to more general metaphysical issues confronting causal realism.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective To analyze the methodological aspects used for the preparation of terminology subsets of the International Classification for Nursing Practice (ICNP®), in dissertations and theses in the Brazilian nursing. Method This is an integrative review of the Brazilian dissertations and theses defended in the period from 2007 to 2013, which were included seven dissertations. Results The increasing production of studies on the theme by Brazilian nurses shows a concern for a unified language for the profession. However, the results demonstrate the lack of uniformity in the conduct of studies, especially in relation to the stages of content validation. The initiatives of some authors to systematize alternative methods for creating these subsets also stood out. Conclusion We suggest the development of new terminology subsets, following standards of methodological rigor, as well as its application and validation by the selected clientele, to ensure greater reliability of results and desired changes for the profession.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Inventories on necrophagous insects carried out in Brazil encompass mostly species from the southeastern and central-western regions of the country. This review aims to produce the first checklist of necrophagous Diptera and Coleoptera species of forensic relevance in northeastern Brazil, an area that concentrates high rates of homicides. We performed a literature survey on scientific articles, theses and dissertations regarding necrophagous insect species in the region, and contacted scientists who develop research on forensic entomology. Fifty-two species of Diptera belonging to eight families with previous record of necrophagy were reported in the region: Sarcophagidae, Calliphoridae, Muscidae, Fanniidae, Piophilidae, Phoridae, Anthomyiidae and Stratiomyidae. Coleopteran species from six families of forensic relevance were registered, although taxonomical identification remained superficial. Bait traps were the most frequent methodology used, followed by collection on animal carcasses. Seven Dipteran species from two families were registered on human cadavers. All species had been previously reported in other Brazilian states and/or other countries, although none has been effectively used in legal procedures in the region. The status of research on forensic entomology in northeastern Brazil is incipient, and the checklist produced here contributes to the knowledge on the local diversity of necrophagous insects.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Lake Banyoles is the second largest lake in the Iberian Peninsula and due to this relative uniqueness, its peculiar geological origin, and its considerable age attracted the early attention of the late Professor Ramon Margalef. One of the first papers by Margalef was on the biota of Lake Banyoles and two of the first four Ph.D. theses that he supervised were about the limnology of this lake. Unfortunately, the uniqueness of this lake also implied that it was the first place of introduction into the Iberian Peninsula of several exotic fish species, early in the XXth Century and nowadays the lake fish assemblage is dominated by invasive species, and some native ones have been extirpated. Although the limnological studies in Lake Banyoles were pioneering within the Iberian Peninsula, studies on fish ecology of the lake did not start until 1989. Thereafter, four Ph.D. theses have been completed on different aspects of the fish assemblages of Lake Banyoles. The aim of this paper is to provide a short overview of this research, largely brought about by the considerable limnological information previously available for this lake, thanks to the insightful, pioneering work of Professor Margalef

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Ara que ja ningú qüestiona les publicacions digitals, l'accés obert o els repositoris de tipus institucional o temàtic, cal co-mençar a treballar en els temes de preservació. Som responsables d'assegurar l'accés i l'ús futurs dels documents digitals, hagin nascut en format digital o siguin fruit dels projectes de digitalització. En aquest article es parla sobre la preservació digital i els tipus de continguts, així com els conceptes, tipologies, costos i usos de l'anomenat «núvol». També es mostra un exemple de núvol privat, la preservació de tesis doctorals del TDX i es comenta una experiència de núvol públic, el DuraCloud.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: The objectives of the present study were to evaluate Aids prevention in drug users attending low threshold centres providing sterile injection equipment in Switzerland, to identify the characteristics of these users, and to monitor the progress of indicators of drug-related harm. METHODS: This paper presents results from a cross-sectional survey carried out in 1994. RESULTS: The mean age of attenders was 28 years, and women represented 27% of the sample. 75% of attenders used a combination of hard drugs (heroin and cocaine). Mean duration of heroin consumption was 8 years, and of cocaine 7 years; 76% of attenders had a fixed abode, but only 34% had stable employment; 45% were being treated with methadone; 9% had shared their injection material in the last 6 months; 24% always used condoms in the case of a stable relationship, and 71% in casual relationships. In a cluster analysis constructed on the basis of multiple correspondence analysis, two distinct profiles of users emerge: highly marginalised users with a high level of consumption (21%); irregular users, better integrated socially, of which the majority are under methadone treatment (79%). CONCLUSION: Theses centres play a major role in Aids prevention. Nevertheless, efforts to improve the hygiene conditions of drug injection in Switzerland should be pursued and extended. At the same time, prevention of HIV sexual transmissions should be reinforced.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Rapport de synthèse : Introduction: la prévalence de l'insuffisance rénale chronique (IRC) augmente et malgré les traitements de remplacement rénal telle que la transplantation ou la dialyse, la mortalité chez des patients atteints d'une IRC reste très élevée. Les maladies cardiovasculaires sont la cause principale de mortalité chez ces patients, et le risque de décès dú à une complication cardiovasculaire est chez eux accru de 10 à 20 fois par rapport à la population générale. Méme si les facteurs de risque cardiovasculaires «traditionnels », principalement l'hypertension artérielle et le diabète sont très prévalents chez les patients avec IRC, ils sont insuffisants pour expliquer l'excès de mortalité cardiovasculaire. D'autres facteurs de risques « nontraditionnels » comme l'accumulation du diméthylarginine asymétrique (ADMA), un inhibiteur endogène de la synthase d'oxyde d'azote (NO), semblent aussi être importants. Chez les patients avec IRC, des taux élevés d'ADMA sont un puissant facteur prédictif indépendant de la mortalité cardiovasculaire. Il a également été démontré chez des souris que l'ADMA peut étre une cause directe de dysfonction endothéliale. Cette dernière joue un rôle primordial dans le développement de l'athérosclérose, cause principale des complications cardiovasculaires. Le but du présent travail est de tester l'hypothèse qu'une réduction du taux d'ADMA après une séance unique d'hémodialyse améliore la dysfonction endothéliale. Méthodes: la dysfonction endothéliale peut être évaluée dans les microvaisseaux de la péan de façon non invasive par fluxmétrie laser Doppler. La vasodilatation cutanée induite par un échauffement local de 34° à 41 °C (hyperémie thermique) est connue pour être dépendante de la production endothéliale de NO et a été utilisée dans plusieurs études cliniques pour évaluer la dysfonction endothéliale. Nous avons recruté 24 patients traités par hémodialyse chronique et également 24 sujets contrôles du même âge et sexe. Chez les patients dialysés, l'hyperémie thermique est mesuré une fois directement avant une séance d'hémodialyse, et une fois directement après une autre séance, toutes deux distantes de 2 à 7 jours. En même temps, les taux plasmatiques d'ADMA sont mesurés par la méthode de spectrométrie de masse en tandem. Chez les sujets contrôle, l'hyperémie thermique est également mesurée à deux reprises, à un intervalle de 2 à 7 jours comme chez les patients dialysés et les taux d'ADMA sont déterminés qu'une seule fois. Résultats: chez les patients dialysés, les réactions d'hyperémie thermique étaient superposables avant et après dialyse, mais moindre que chez les sujets contrôles. Par contre, les taux d'ADMA étaient plus élevés avant qu'après dialysé. Les taux d'ADMA après dialyse étaient similaires aux taux chez les sujets contrôles. Conclusion: cette étude montre que la vasodilatation dépendante de la production endothéliale de NO dans la microcirculation cutanée n'est pas influencée par les taux plasmatiques d'ADMA chez les patients dialysés. Ces résultats suggèrent que d'autres mécanismes sont responsables de la dysfonction endothéliale chez ces patients. Ceci met en question le concept que l'accumulation d'ADMA est un facteur causal du risque cardiovasculaire élevé et suggère que l'ADMA est juste un marqueur du milieu très athérogénique causé par l'IRC.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Phosphorylation of transcription factors is a rapid and reversible process linking cell signaling and control of gene expression, therefore understanding how it controls the transcription factor functions is one of the challenges of functional genomics. We performed such analysis for the forkhead transcription factor FOXC2 mutated in human hereditary disease lymphedemadistichiasis and important for the development of venous and lymphatic valves and lymphatic collecting vessels. We found that FOXC2 is phosphorylated in a cell-cycle dependent manner on eight evolutionary conserved serine/threonine residues, seven of which are clustered within a 70 amino acid domain. Surprisingly, the mutation of phosphorylation sites or a complete deletion of the domain did not affect the transcriptional activity of FOXC2 in a synthetic reporter assay. However, overexpression of the wild type or phosphorylation-deficient mutant resulted in overlapping but distinct gene expression profiles suggesting that binding of FOXC2 to individual sites under physiological conditions is affected by phosphorylation. To gain a direct insight into the role of FOXC2 phosphorylation, we performed comparative genome-wide location analysis (ChIP-chip) of wild type and phosphorylation-deficient FOXC2 in primary lymphatic endothelial cells. The effect of loss of phosphorylation on FOXC2 binding to genomic sites ranged from no effect to nearly complete inhibition of binding, suggesting a mechanism for how FOXC2 transcriptional program can be differentially regulated depending on FOXC2 phosphorylation status. Based on these results, we propose an extension to the enhanceosome model, where a network of genomic context-dependent DNA-protein and protein-protein interactions not only distinguishes a functional site from a nonphysiological site, but also determines whether binding to the functional site can be regulated by phosphorylation. Moreover, our results indicate that FOXC2 may have different roles in quiescent versus proliferating lymphatic endothelial cells in vivo.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Résumé Il est actuellement reconnu que l'endothélium vasculaire joue un rôle primordial dans la genèse des maladies cardiovasculaires, notamment l'artériosclérose. Dès lors, il est important de pouvoir investiguer la fonction endothéliale en clinique. Pour ce faire, il est particulièrement simple d'examiner la microcirculation cutanée, car celle-ci est très simplement accessible, de manière non-invasive, par fluxmétrie laser-Doppler. Pratiquement, on mesure l'augmentation du flux sanguin dermique en réponse à des stimuli connus pour agir via l'endothélium vasculaire. Les stimuli endothélium-dépendants les plus courants sont l'interruption temporaire du flux sanguin qui est suivie d'une hyperémie réactive, et l'administration transcutanée d'acétylcholine (Ach) par iontophorèse. La iontophorèse consiste à obtenir le transfert d' une substance ionisée, telle l'Ach, par l'application d'un courant électrique de polarité appropriée. L'objectif du présent travail était de déterminer le rôle des prostaglandines dans ces réponse vasodilatatrices dépendante de l'endothélium, rôle actuellement peu clair. 23 jeunes hommes volontaires non fumeurs et en bonne santé habituelle ont été examinés lors de deux visites séparées par 1 à 3 semaines. Lors de chaque visite, l'hyperémie réactive et la réponse vasodilatatrice à l'Ach ont été déterminées dans la peau de l'avant bras après administration soit d'un placebo, soit d'un inhibiteur de la cyclooxygénase (COX, enzyme qui contrôle la synthèse des prostaglandines). Chez certains sujets, l'inhibiteur était de l'acétylsalicylate de lysine (900 mg par voie intraveineuse). Chez d'autres sujets, il s'agissait d'indométhacine. (75 mg par voie orale). Comme la stimulation nociceptive liée au courant iontophorétique peut influencer la réponse à l'Ach, celle-ci a été déterminée en présence et en l'absence d'anesthésie de surface (crème de lidocaine). La réponse à l'Ach a été obtenue pour 4 doses différentes de cet agent (exprimées sous la forme de la densité de charge iontophorétique appliquée : 0.28, 1.4, 7, et 14 millicoulombs par cm2 de peau exposée). Le flux sanguin dermique était mesuré par imagerie laser-Doppler, une variante de la fluxmétrie laser-Doppler classique permettant l'exploration d'une surface de peau de taille arbitraire. Quelle que soit la condition testée, nous n'avons jamais observé la moindre influence de l'inhibition de la COX sur l'hyperémie réactive, ni sur la réponse à l'Ach. Cette dernière était augmentée significativement par l'anesthésie cutanée, que les sujets aient reçu ou non de l'acétylsalicylate de lysine ou de l'indométhacine . Par exemple, la réponses moyenne (±SD) à la plus haute dose d'Ach (testée sur 6 sujets, et exprimée en unités de perfusion, comme il est d'usage en fluxmétrie laser-Doppler ) était la suivante : en l'absence d'anesthésie : acétylsalicylate de lysine 339 ± 105, placebo 344 ± 68 ; avec l'anesthésie : acétylsalicylate de lysine 453 ± 76 , placebo 452 ± 65 (p * 0.001 pour les effets de l'anesthésie). En conclusion, nos résultats infirment une contribution des prostaglandines à l'hyperémie réactive ou à la vasodilatation induite par l'acétylcholine dans la microcirculation cutanée. Dans ce lit vasculaire, l'anesthésie locale accroît la vasodilatation induite par l'acétylcholine par un mécanisme indépendant des prostaglandines.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Asbestos is an industrial term to describe some fibrous silicate minerals, which belong to the amphiboles or serpentines group. Six minerals are defined as asbestos including: chrysotile (white asbestos), amosite (grunerite, brown asbestos), crocidolite (riebeckite, blue asbestos), anthophyllite, tremolite and actonolite, but only in their fibrous form. In 1973, the IARC (International Agency for Research on Cancer) classified the asbestos minerals as carcinogenic substances (IARC,1973). The Swiss threshold limit (VME) is 0.01 fibre/ml (SUVA, 2007). Asbestos in Switzerland has been prohibited since 1990, but this doesn't mean we are over asbestos. Up to 20'000 tonnes/year of asbestos was imported between the end of WWII and 1990. Today, all this asbestos is still present in buildings renovated or built during that period of time. During restorations, asbestos fibres can be emitted into the air. The quantification of the emission has to be evaluated accurately. To define the exact risk on workers or on the population is quite hard, as many factors must be considered. The methods to detect asbestos in the air or in materials are still being discussed today. Even though the EPA 600 method (EPA, 1993) has proved itself for the analysis of bulk materials, the method for air analysis is more problematic. In Switzerland, the recommended method is VDI 3492 using a scanning electron microscopy (SEM), but we have encountered many identifications problems with this method. For instance, overloaded filters or long-term exposed filters cannot be analysed. This is why the Institute for Work and Health (IST) has adapted the ISO10312 method: ambient air - determination of asbestos fibres - direct-transfer transmission electron microscopy (TEM) method (ISO, 1995). Quality controls have already be done at a French institute (INRS), which validate our practical experiences. The direct-transfer from MEC's filters on TEM's supports (grids) is a delicate part of the preparation for analysis and requires a lot of trials in the laboratory. IST managed to do proper grid preparations after about two years of development. In addition to the preparation of samples, the micro-analysis (EDX), the micro-diffraction and the morphologic analysis (figure 1.a-c) are also to be mastered. Theses are the three elements, which prove the different features of asbestos identification. The SEM isn't able to associate those three analyses. The TEM is also able to make the difference between artificial and natural fibres that have very similar chemical compositions as well as differentiate types of asbestos. Finally the experiments concluded by IST show that TEM is the best method to quantify and identify asbestos in the air.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

El pasado mes de junio se celebró en Pittsburgh, EE.UU., el duodécimo simposio internacional sobre tesis electrónicas: Electronic Thesis and Dissertations Conference (ETD2009). Fue organizado por Networked Digital Library of Theses and Dissertations (NDLTD). La mayoría de los ponentes explicaron las experiencias de su propia universidad. Además, hubo expertos invitados entre los cuales se pueden destacar Stevan Harnad (Univ. Southampton), Karla Hahn (Association of Research Libraries) y Deanna Marcum (Library of Congress). Estos simposios pretenden promover la adopción, creación, uso, difusión y preservación de las tesis electrónicas. De hecho, el éxito ha sido tal, que algunas universidades ya prescinden de la copia en papel para el depósito y preservación del documento. Un caso reciente es el de la University of Albany cuya nueva política, anunciada durante el simposio, consiste en que a partir de setiembre del 2009 ya no requiere el depósito de una copia impresa de las tesis aprobadas en aquella universidad.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Introduction. The DRIVER I project drew up a detailed report of European repositories based on data gathered in a survey in which Spain's participation was very low. This created a highly distorted image of the implementation of repositories in Spain. This study aims to analyse the current state of Spanish open-access institutional repositories and to describe their characteristics. Method. The data were gathered through a Web survey. The questionnaire was based on that used by DRIVER I: coverage; technical infrastructure and technical issues; institutional policies; services created; and stimulators and inhibitors for establishing, filling and maintaining their digital institutional repositories. Analysis. Data were tabulated and analysed systematically according responses obtained from the questionnaire and grouped by coverage. Results. Responses were obtained from 38 of the 104 institutions contacted, which had 29 institutional repositories. This represents 78.3% of the Spanish repositories according to the BuscaRepositorios directory. Spanish repositories contained mainly full-text materials (journal articles and doctoral theses) together with metadata. The software most used was DSpace, followed by EPrints. The metadata standard most used was Dublin Core. Spanish repositories offered more usage statistics and fewer author-oriented services than the European average. The priorities for the future development of the repositories are the need for clear policies on access to scientific production based on public funding and the need for quality control indicators. Conclusions.This is the first detailed study of Spanish institutional repositories. The key stimulants for establishing, filling and maintaining were, in order of importance, the increase of visibility and citation, the interest of decision-makers, simplicity of use and search services. On the other hand the main inhibitors identified were the absence of policies, the lack of integration with other national and international systems and the lack of awareness efforts among academia.