804 resultados para the self


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OBJECTIVES: HLA-B*5701 is a major histocompatibility complex class I allele associated with an immunologically-mediated hypersensitivity reaction to abacavir. The objectives of this study were to evaluate HLA-B*5701 prevalence among European, HIV-1-infected patients and to compare the local and central laboratory screening results. METHODS: Data were combined from six multicentre, prospective studies involving 10 European countries in which HIV-1-infected patients (irrespective of treatment experience or previous HLA-B*5701 screening), >or=18 years of age, were evaluated for HLA-B*5701 carriage, determined by the central and local laboratory methods. RESULTS: A total of 9720 patients from 272 centres were included in the analysis. The overall estimate of HLA-B*5701 prevalence in Europe was 4.98%, with country-specific estimates ranging from 1.53 to 7.75%. HLA-B*5701 prevalence was highest in the self-reported white population (6.49%) and lowest in the black population (0.39%). Local laboratory results had a high specificity (99.9%) and sensitivity (99.2%) when compared with the central laboratory results. CONCLUSION: This study supports data from previous studies regarding the prevalence of HLA-B*5701 in the HIV population and the variation of HLA-B*5701 prevalence between different racial groups. The high specificity and sensitivity of local laboratory results, suggests that clinicians can be confident in using local laboratories for pretreatment HLA-B*5701 screening. However, it is essential that local laboratories participate in HLA-B*5701-specific quality assurance programs to maintain 100% sensitivity. In HIV-infected patients, pretreatment HLA-B*5701 screening may allow more informed decisions regarding abacavir use and has the potential to significantly reduce the frequency of abacavir-related hypersensitivity reactions and costs associated with managing these reactions.

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The present study is an integral part of a broader study focused on the design and implementation of self-cleaning culverts, i.e., configurations that prevent the formation of sediment deposits after culvert construction or cleaning. Sediment deposition at culverts is influenced by many factors, including the size and characteristics of material of which the channel is composed, the hydraulic characteristics generated under different hydrology events, the culvert geometry design, channel transition design, and the vegetation around the channel. The multitude of combinations produced by this set of variables makes the investigation of practical situations a complex undertaking. In addition to the considerations above, the field and analytical observations have revealed flow complexities affecting the flow and sediment transport through culverts that further increase the dimensions of the investigation. The flow complexities investigated in this study entail: flow non-uniformity in the areas of transition to and from the culvert, flow unsteadiness due to the flood wave propagation through the channel, and the asynchronous correlation between the flow and sediment hydrographs resulting from storm events. To date, the literature contains no systematic studies on sediment transport through multi-box culverts or investigations on the adverse effects of sediment deposition at culverts. Moreover, there is limited knowledge about the non-uniform, unsteady sediment transport in channels of variable geometry. Furthermore, there are few readily useable (inexpensive and practical) numerical models that can reliably simulate flow and sediment transport in such complex situations. Given the current state of knowledge, the main goal of the present study is to investigate the above flow complexities in order to provide the needed insights for a series of ongoing culvert studies. The research was phased so that field observations were conducted first to understand the culvert behavior in Iowa landscape. Modeling through complementary hydraulic model and numerical experiments was subsequently carried out to gain the practical knowledge for the development of the self-cleaning culvert designs.

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Spermatogenesis relies on the precise regulation of the self-renewal and differentiation of spermatogonia to provide a continuous supply of differentiating germ cells. The understanding of the cellular pathways regulating this equilibrium remains unfortunately incomplete. This investigation aimed to elucidate the testicular and ovarian functions of the glucocorticoid-induced leucine zipper protein (GILZ) encoded by the X-linked Tsc22d3 (Gilz) gene. We found that GILZ is specifically expressed in the cytoplasm of proliferating spermatogonia and preleptotene spermatocytes. While Gilz mutant female mice were fully fertile, constitutive or male germ cell-specific ablation of Gilz led to sterility due to a complete absence of post-meiotic germ cells and mature spermatozoa. Alterations were observed as early as postnatal day 5 during the first spermatogenic wave and included extensive apoptosis at the spermatogonial level and meiotic arrest in the mid-late zygotene stage. Overall, these data emphasize the essential role played by GILZ in mediating spermatogonial survival and spermatogenesis.

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Respiratory motion is a major source of artifacts in cardiac magnetic resonance imaging (MRI). Free-breathing techniques with pencil-beam navigators efficiently suppress respiratory motion and minimize the need for patient cooperation. However, the correlation between the measured navigator position and the actual position of the heart may be adversely affected by hysteretic effects, navigator position, and temporal delays between the navigators and the image acquisition. In addition, irregular breathing patterns during navigator-gated scanning may result in low scan efficiency and prolonged scan time. The purpose of this study was to develop and implement a self-navigated, free-breathing, whole-heart 3D coronary MRI technique that would overcome these shortcomings and improve the ease-of-use of coronary MRI. A signal synchronous with respiration was extracted directly from the echoes acquired for imaging, and the motion information was used for retrospective, rigid-body, through-plane motion correction. The images obtained from the self-navigated reconstruction were compared with the results from conventional, prospective, pencil-beam navigator tracking. Image quality was improved in phantom studies using self-navigation, while equivalent results were obtained with both techniques in preliminary in vivo studies.

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We propose a procedure for analyzing and characterizing complex networks. We apply this to the social network as constructed from email communications within a medium sized university with about 1700 employees. Email networks provide an accurate and nonintrusive description of the flow of information within human organizations. Our results reveal the self-organization of the network into a state where the distribution of community sizes is self-similar. This suggests that a universal mechanism, responsible for emergence of scaling in other self-organized complex systems, as, for instance, river networks, could also be the underlying driving force in the formation and evolution of social networks.

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The influence of the pseudopotential on both the structure and the self-diffusion of liquid rubidium at the melting point has been investigated by means of molecular-dynamics calculations. The model potential considered has been computed from the pseudopotential of Ashcroft, the dielectric function of Geldart and Vosko, and a Born-Mayer term. Four different values for the core radius which enters as input in the pseudopotential have been considered. In this way we have been able to observe and interpret the effect of this contribution on the properties of the liquid.

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BACKGROUND: Recently, a compact cardiopulmonary support (CPS) system designed for quick set-up for example, during emergency cannulation, has been introduced. Traditional rectilinear percutaneous cannulas are standard for remote vascular access with the original design. The present study was designed to assess the potential of performance increase by the introduction of next-generation, self-expanding venous cannulas, which can take advantage of the luminal width of the venous vasculature despite a relatively small access orifice. METHODS: Veno-arterial bypass was established in three bovine experiments (69+/-10 kg). The Lifebridge (Lifebridge GmbH, Munich, Germany) system was connected to the right atrium in a trans-jugular fashion with various venous cannulas; and the oxygenated blood was returned through the carotid artery with a 17 F percutaneous cannula. Two different venous cannulas were studied, and the correlation between the centrifugal pump speed (1500-3900 RPM), flow and the required negative pressure on the venous side was established: (A) Biomedicus 19 F (Medtronic, Tolochenaz, Switzerland); (B) Smart canula 18 F/36 F (Smartcanula LLC, Lausanne, Switzerland). RESULTS: At 1500 RPM, the blood flow was 0.44+/-0.26 l min(-1) for the 19 F rectilinear cannula versus 0.73+/-0.34 l min(-1) for the 18/36 F self-expanding cannula. At 2500 RPM the blood flow was 1.63+/-0.62 l min(-1) for the 19F rectilinear cannula versus 2.13+/-0.34 l min(-1) for the 18/36 F self-expanding cannula. At 3500 RPM, the blood flow was 2.78+/-0.47 l min(-1) for the 19 F rectilinear cannula versus 3.64+/-0.39 l min(-1) for the 18/36 F self-expanding cannula (p<0.01 for 18/36 F vs 19 F). At 1500 RPM, the venous line pressure was 18+/-8 mmHg for the 19F rectilinear cannula versus 19+/-5 mmHg for the 18/36 F self-expanding cannula. At 2500 RPM the venous line pressure accounted for -22+/-32 mmHg for the 19 F rectilinear cannula versus 2+/-5 mmHg for the 18/36 F self-expanding cannula. At 3500 RPM, the venous line pressure was -112+/-42 mmHg for the rectilinear cannula versus 28+/-7 mmHg for the 18/36 F self-expanding cannula (p<0.01 for 18 F/36 F vs 19 F). Conclusions: The negative pressure required to achieve adequate venous drainage with the self-expanding venous cannula accounts for approximately 31% of the pressure necessary with the 19 F rectilinear cannula. In addition, a pump flow of more than 4 l min(-1) can be achieved with the self-expanding design and a well-accepted negative inlet pressure for minimal blood trauma of less than 50 mmHg.

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AIMS: Managing patients with alcohol dependence includes assessment for heavy drinking, typically by asking patients. Some recommend biomarkers to detect heavy drinking but evidence of accuracy is limited. METHODS: Among people with dependence, we assessed the performance of disialo-carbohydrate-deficient transferrin (%dCDT, ≥1.7%), gamma-glutamyltransferase (GGT, ≥66 U/l), either %dCDT or GGT positive, and breath alcohol (> 0) for identifying 3 self-reported heavy drinking levels: any heavy drinking (≥4 drinks/day or >7 drinks/week for women, ≥5 drinks/day or >14 drinks/week for men), recurrent (≥5 drinks/day on ≥5 days) and persistent heavy drinking (≥5 drinks/day on ≥7 consecutive days). Subjects (n = 402) with dependence and current heavy drinking were referred to primary care and assessed 6 months later with biomarkers and validated self-reported calendar method assessment of past 30-day alcohol use. RESULTS: The self-reported prevalence of any, recurrent and persistent heavy drinking was 54, 34 and 17%. Sensitivity of %dCDT for detecting any, recurrent and persistent self-reported heavy drinking was 41, 53 and 66%. Specificity was 96, 90 and 84%, respectively. %dCDT had higher sensitivity than GGT and breath test for each alcohol use level but was not adequately sensitive to detect heavy drinking (missing 34-59% of the cases). Either %dCDT or GGT positive improved sensitivity but not to satisfactory levels, and specificity decreased. Neither a breath test nor GGT was sufficiently sensitive (both tests missed 70-80% of cases). CONCLUSIONS: Although biomarkers may provide some useful information, their sensitivity is low the incremental value over self-report in clinical settings is questionable.

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Human-Computer Interaction (HCI) is a challenging discipline that is currently concerned with the design, implementation and evaluation of interactive systems for human use, as well as the study of major phenomena surrounding them. Indeed, interdisciplinary communities formed by scientists, university teachers and students, people coming from the industry and customers related to HCI are emerging in different parts of the world. In particular, this article overviews the HCI community in the Ibero-American context, which involves hundreds of millions of people working or studying in HCI, whose cultural background is primarily associated with the Spanish and Portuguese languages and cultures, regardless of ethnic and geographical differences. Our final goal is to improve the visibility of this particular HCI community, enhancing the self awareness of its members and their individual motivation and future exchanges.

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Background: Diverse projects and guidelines to assist hospitals towards the attainment of comprehensive smoke-free policies have been developed. In 2006, Spain government passed a new smoking ban that reinforce tobacco control policies and banned completely smoking in hospitals. This study assesses the progression of tobacco control policies in the Catalan Network of Smokefree Hospitals before and after a comprehensive national smoking ban. Methods: We used the Self-Audit Questionnaire of the European Network for Smoke-free Hospitals to score the compliance of 9 policy standards (global score = 102). We used two crosssectional surveys to evaluate tobacco control policies before (2005) and after the implementation of a national smoking ban (2007) in 32 hospitals of Catalonia, Spain. We compared the means of the overall score in 2005 and 2007 according to the type of hospital, the number of beds, the prevalence of tobacco consumption, and the number of years as a smoke-free hospital. Results: The mean of the implementation score of tobacco control policies was 52.4 (95% CI:45.4-59.5) in 2005 and 71.6 (95% CI: 67.0-76.2) in 2007 with an increase of 36.7% (p < 0.01). The hospitals with greater improvement were general hospitals (48% increase; p < 0.01), hospitals with > 300 beds (41.1% increase; p < 0.01), hospitals with employees' tobacco consumption prevalence 35-39% (72.2% increase; p < 0.05) and hospitals that had recently implemented smoke-free policies (74.2% increase; p < 0.01). Conclusion: The national smoking ban appears to increase tobacco control activities in hospitals combined with other non-bylaw initiatives such as the Smoke-free Hospital Network.

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Background: Diverse projects and guidelines to assist hospitals towards the attainment of comprehensive smoke-free policies have been developed. In 2006, Spain government passed a new smoking ban that reinforce tobacco control policies and banned completely smoking in hospitals. This study assesses the progression of tobacco control policies in the Catalan Network of Smokefree Hospitals before and after a comprehensive national smoking ban. Methods: We used the Self-Audit Questionnaire of the European Network for Smoke-free Hospitals to score the compliance of 9 policy standards (global score = 102). We used two crosssectional surveys to evaluate tobacco control policies before (2005) and after the implementation of a national smoking ban (2007) in 32 hospitals of Catalonia, Spain. We compared the means of the overall score in 2005 and 2007 according to the type of hospital, the number of beds, the prevalence of tobacco consumption, and the number of years as a smoke-free hospital. Results: The mean of the implementation score of tobacco control policies was 52.4 (95% CI:45.4-59.5) in 2005 and 71.6 (95% CI: 67.0-76.2) in 2007 with an increase of 36.7% (p < 0.01). The hospitals with greater improvement were general hospitals (48% increase; p < 0.01), hospitals with > 300 beds (41.1% increase; p < 0.01), hospitals with employees' tobacco consumption prevalence 35-39% (72.2% increase; p < 0.05) and hospitals that had recently implemented smoke-free policies (74.2% increase; p < 0.01). Conclusion: The national smoking ban appears to increase tobacco control activities in hospitals combined with other non-bylaw initiatives such as the Smoke-free Hospital Network.

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Strategies for expanding hematopoietic stem cells (HSCs) include coculture with cells that recapitulate their natural microenvironment, such as bone marrow stromal stem/progenitor cells (BMSCs). Plastic-adherent BMSCs may be insufficient to preserve primitive HSCs. Here, we describe a method of isolating and culturing human BMSCs as nonadherent mesenchymal spheres. Human mesenspheres were derived from CD45- CD31- CD71- CD146+ CD105+ nestin+ cells but could also be simply grown from fetal and adult BM CD45--enriched cells. Human mesenspheres robustly differentiated into mesenchymal lineages. In culture conditions where they displayed a relatively undifferentiated phenotype, with decreased adherence to plastic and increased self-renewal, they promoted enhanced expansion of cord blood CD34+ cells through secreted soluble factors. Expanded HSCs were serially transplantable in immunodeficient mice and significantly increased long-term human hematopoietic engraftment. These results pave the way for culture techniques that preserve the self-renewal of human BMSCs and their ability to support functional HSCs.

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The local thermodynamics of a system with long-range interactions in d dimensions is studied using the mean-field approximation. Long-range interactions are introduced through pair interaction potentials that decay as a power law in the interparticle distance. We compute the local entropy, Helmholtz free energy, and grand potential per particle in the microcanonical, canonical, and grand canonical ensembles, respectively. From the local entropy per particle we obtain the local equation of state of the system by using the condition of local thermodynamic equilibrium. This local equation of state has the form of the ideal gas equation of state, but with the density depending on the potential characterizing long-range interactions. By volume integration of the relation between the different thermodynamic potentials at the local level, we find the corresponding equation satisfied by the potentials at the global level. It is shown that the potential energy enters as a thermodynamic variable that modifies the global thermodynamic potentials. As a result, we find a generalized Gibbs-Duhem equation that relates the potential energy to the temperature, pressure, and chemical potential. For the marginal case where the power of the decaying interaction potential is equal to the dimension of the space, the usual Gibbs-Duhem equation is recovered. As examples of the application of this equation, we consider spatially uniform interaction potentials and the self-gravitating gas. We also point out a close relationship with the thermodynamics of small systems.

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This paper analyses the effects of manipulating the cognitive complexity of L2 oral tasks on language production. It specifically focuses on self-repairs, which are taken as a measure of accuracy since they denote both attention to form and an attempt at being accurate. By means of a repeated measures de- sign, 42 lower-intermediate students were asked to perform three different tasks types (a narrative, and instruction-giving task, and a decision-making task) for which two degrees of cognitive complexity were established. The narrative task was manipulated along +/− Here-and-Now, an instruction-giving task ma- nipulated along +/− elements, and the decision-making task which is manipu- lated along +/− reasoning demands. Repeated measures ANOVAs are used for the calculation of differences between degrees of complexity and among task types. One-way ANOVA are used to detect potential differences between low- proficiency and high-proficiency participants. Results show an overall effect of Task Complexity on self-repairs behavior across task types, with different be- haviors existing among the three task types. No differences are found between the self-repair behavior between low and high proficiency groups. Results are discussed in the light of theories of cognition and L2 performance (Robin- son 2001a, 2001b, 2003, 2005, 2007), L1 and L2 language production models (Levelt 1989, 1993; Kormos 2000, 2006), and attention during L2 performance (Skehan 1998; Robinson, 2002).

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Tässä diplomityössä on perehdytty kaaoksen ja oppivan organisaation mekaniikkaan ja olemukseen. Niitä on sovellettu uuden tuotteen saattamiseen logistiikan toimitusketjuun Nokia Oyj:n Networks toimialaryhmässä. Samalla on pyritty löytämään ratkaisuja toiminnan parantamiseksi. Kaaosjohtaminen tarjoaa prosessijohtamista täydentävän tavan mallintaa muutosta ja selittää sen aikaansaamia ilmiöitä. Näiden kahden viitekehyksen avulla on pyritty pureutumaan laajaan ja moniulotteiseen ongelmakenttään. Muotoaan hakevassa organisaatiossa kaaoksen elementit ovat voimakkaasti läsnä. Kaaoksen hallintaan liittyy saumattomasti itseorganisoituminen ja oppiminen. Oppinen ei ole organisaatiolle yhtä luontainen kyky kuin se on yksilölle. Se vaatii organisaation jäseniltä oman roolinsa tiedostamista ja tiedon jakamista. Organisaation tavoitteet saattavat yksilön näkökulmasta tuntua joskus epäkonkreettisilta ja samalla muutokset hallitsemattomilta. Markkinoiden ja teknologian muuttuminen on ollut erityisen nopeaa telekommunikaatioalalla. Näissä olosuhteissa on tärkeää pyrkiä oppivaan organisaatioon, joka tukee organisaation toimintaa läpi muutoksen.