992 resultados para Re-introduction


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Projecte de recerca elaborat a partir d’una estada al Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy entre setembre i desembre 2007. Els materials monocristal•lins tungstats dobles de potassi i terra rara, KRE(WO4)2, a partir d'ara KREW, són en l'actualitat un material competitiu com a material actiu per sistemes de làser d'estat sòlid. Aquests materials monoclínics són fàcils de dopar amb altres densitats de ions lantànid, Ln3+, i a més presenten unes seccions eficaces d'absorció i d'emissió, molt elevades. Dins d’aquesta família, destaca el KLuW; degut als seus millors resultats com a material làser. Durant aquesta estada d’un mes al laboratori Max Born de Berlin, s’han realitzat les mesures de conductivitat tèrmica d’aquest material, per tal de obtenir el seu tensor de segon ordre de conductivitat tèrmica. El bombeig òptic dels materials làser d’estat sòlid genera calor com a resultat de la termalització en els multiplets, de les relaxacions no-radiatives i de les absorcions residuals (defectes, impureses). Per tant, el coneixement de les propietats tèrmiques de qualsevol material actiu és essencial pel disseny de la cavitat làser i l’avaluació de la funció làser, especialment en règims d’altes potències(...)

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This paper examines the impact of salt iodization in Switzerland in the 1920s and 1930s on schooling outcomes. Iodine deficiency in utero causes mental retardation, and correcting the deficiency is expected to increase the productivity of a population by increasing its cognitive ability. The exogenous increase in cognitive ability brought about by the iodization program is also useful in the context of disentangling the effects of innate ability and education in later-life outcomes. I identify the impact of iodization in three ways: first, in a differences-in-differences framework, I exploit geographic variation in iodine deficiency, as well as the fact that the nationwide campaign to decrease iodine deficiency began in 1922. Second, I use spatial and temporal variation in the introduction of iodized salt across Swiss cantons, and examine whether the level of iodized salt sales at the time of one’s birth affected one’s educational attainment. Third, I employ a fuzzy regression discontinuity design and use jumps in sales of iodized salt across Swiss cantons to identify the effect of iodization, by comparing outcomes for those born right before and right after these sudden changes in the treatment environment. These approaches indicate that the eradication of iodine deficiency in previously deficient areas increased the schooling of the population significantly. The effects are larger for females than for males, which is consistent with medical evidence showing that women are more likely to be affected by iodine deficiency disorders than men.

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Background: Beryllium (Be) is increasingly used worldwide for numerous industrial applications. Occupational exposure to Be may lead to Be sensitization (BeS), a CD4-mediated immune response. BeS may progress to chronic beryllium disease (CBD), a granulomatous lung disorder closely resembling sarcoidosis. The recognition of CBD requires detection of Be exposure at occupational history, and detection of BeS on blood or BAL lymphocytes. Since methods for CBD detection are not routinely available in Switzerland, we hypothesized that CBD cases are not recognized but misdiagnosis as sarcoidosis. Objective: To present an ongoing Swiss study screening patients with sarcoidosis in search of Be exposure, BeS, and CBD. Methods: Both a prospective and a retrospective cohort are being studied. In the prospective cohort, the main steps include: 1) recruitment of 100 consecutive patients with newly diagnosed pulmonary sarcoidosis at 2 centers (Lausanne, Bern). 2) screening for possible occupational Be exposure by self-administered patient questionnaire. 3) standardized detailed occupational interview and clinical visit by occupational health specialist. If step 3 is positive, then 4) blood and BAL sampling for detection of BeS by specifically developed Elispot assay and CFSE flow cytometry, with subsequent comparison to the classical Be lymphocyte proliferation test. If step 4 is positive, then 5) review of medical records and diagnostic revision from sarcoidosis to CBD. 6) appropriate measures for exposure cessation and case reporting to SUVA as occupational disease. The retrospective cohort will include 400 patients with previously diagnosed pulmonary sarcoidosis, either treated or untreated, recruited through the SIOLD Registries. Steps 2 to 5 will be peformed as above, except for a) end of study after step 2 if screening questionnaire does not reveal Be exposure, and b) step 4 done on blood sample only (BAL not needed). Current status: Self-administered screening questionnaire and tools for standardized occupational interview have been developed. BeS testing has been implemented and undergoes validation. Inclusions in the prospective phase have started at both study sites. The retrospective phase is in preparation. Conclusion: The current study status allows to conclude to technical feasibility of the project. The prospective phase if this study is funded by the SUVA. The SIOLD Registries are supported by the Swiss Pulmonary League.

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INTRODUCTION: Therapeutic hypothermia (TH) is often used to treat out-of-hospital cardiac arrest (OHCA) patients who also often simultaneously receive insulin for stress-induced hyperglycaemia. However, the impact of TH on systemic metabolism and insulin resistance in critical illness is unknown. This study analyses the impact of TH on metabolism, including the evolution of insulin sensitivity (SI) and its variability, in patients with coma after OHCA. METHODS: This study uses a clinically validated, model-based measure of SI. Insulin sensitivity was identified hourly using retrospective data from 200 post-cardiac arrest patients (8,522 hours) treated with TH, shortly after admission to the intensive care unit (ICU). Blood glucose and body temperature readings were taken every one to two hours. Data were divided into three periods: 1) cool (T <35°C); 2) an idle period of two hours as normothermia was re-established; and 3) warm (T >37°C). A maximum of 24 hours each for the cool and warm periods was considered. The impact of each condition on SI is analysed per cohort and per patient for both level and hour-to-hour variability, between periods and in six-hour blocks. RESULTS: Cohort and per-patient median SI levels increase consistently by 35% to 70% and 26% to 59% (P <0.001) respectively from cool to warm. Conversely, cohort and per-patient SI variability decreased by 11.1% to 33.6% (P <0.001) for the first 12 hours of treatment. However, SI variability increases between the 18th and 30th hours over the cool to warm transition, before continuing to decrease afterward. CONCLUSIONS: OCHA patients treated with TH have significantly lower and more variable SI during the cool period, compared to the later warm period. As treatment continues, SI level rises, and variability decreases consistently except for a large, significant increase during the cool to warm transition. These results demonstrate increased resistance to insulin during mild induced hypothermia. Our study might have important implications for glycaemic control during targeted temperature management.

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We analyse both theoretically and empirically, the factors that influence the amount of humanitarian aid which countries receive when they are struck by natural disasters. Our investigation particularly distinguishes between immediate disaster relief which helps the survival of victims and long term humanitarian aid given towards reconstruction and rehabilitation. The theoretical model is able to make predictions as well as explain some of the peculiarities in the empirical results. The empirical analysis, making use of some useful data sources, show that both short and long term humanitarian aid increase with number of people killed, financial loss and level of corruption, while GDP per capita has no effect. Number of people affected had no effect on short term aid, but significantly increased long term aid. Both types of aid increased if the natural disaster was an earthquake, tsunami or drought. In addition, short term aid increases in response to a flood while long term aid increases in response to storms.

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Starting from the observation that ghosts are strikingly recurrent and prominent figures in late-twentieth African diasporic literature, this dissertation proposes to account for this presence by exploring its various functions. It argues that, beyond the poetic function the ghost performs as metaphor, it also does cultural, theoretical and political work that is significant to the African diaspora in its dealings with issues of history, memory and identity. Toni Morrison's Beloved (1987) serves as a guide for introducing the many forms, qualities and significations of the ghost, which are then explored and analyzed in four chapters that look at Fred D'Aguiar's Feeding the Ghosts (1998), Gloria Naylor's Mama Day (1988), Paule Marshall's Praisesong for the Widow (1983) and a selection of novels, short stories and poetry by Michelle Cliff. Moving thematically through these texts, the discussion shifts from history through memory to identity as it examines how the ghost trope allows the writers to revisit sites of trauma; revise historical narratives that are constituted and perpetuated by exclusions and invisibilities; creatively and critically repossess a past marked by violence, dislocation and alienation and reclaim the diasporic culture it contributed to shaping; destabilize and deconstruct the hegemonic, normative categories and boundaries that delimit race or sexuality and envision other, less limited and limiting definitions of identity. These diverse and interrelated concerns are identified and theorized as participating in a project of "re-vision," a critical project that constitutes an epistemological as much as a political gesture. The author-based structure allows for a detailed analysis of the texts and highlights the distinctive shapes the ghost takes and the particular concerns it serves to address in each writer's literary and political project. However, using the ghost as a guide into these texts, taken collectively, also throws into relief new connections between them and sheds light on the complex ways in which the interplay of history, memory and identity positions them as products of and contributions to an African diasporic (literary) culture. If it insists on the cultural specificity of African diasporic ghosts, tracing its origins to African cultures and spiritualities, the argument also follows gothic studies' common view that ghosts in literary and cultural productions-like other related figures of the living dead-respond to particular conditions and anxieties. Considering the historical and political context in which the texts under study were produced, the dissertation makes connections between the ghosts in them and African diasporic people's disillusionment with the broken promises of the civil rights movement in the United States and of postcolonial independence in the Caribbean. It reads the texts' theoretical concerns and narrative qualities alongside the contestation of traditional historiography by black and postcolonial studies as well as the broader challenge to conventional notions such as truth, reality, meaning, power or identity by poststructuralism, postcolonialism or queer theory. Drawing on these various theoretical approaches and critical tools to elucidate the ghost's deconstructive power for African diasporic writers' concerns, this work ultimately offers a contribution to "speciality studies," which is currently emerging as a new field of scholarship in cultural theory.

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PURPOSE: To introduce a new k-space traversal strategy for segmented three-dimensional echo planar imaging (3D EPI) that encodes two partitions per radiofrequency excitation, effectively reducing the number excitations used to acquire a 3D EPI dataset by half. METHODS: The strategy was evaluated in the context of functional MRI applications for: image quality compared with segmented 3D EPI, temporal signal-to-noise ratio (tSNR) (the ability to detect resting state networks compared with multislice two-dimensional (2D) EPI and segmented 3D EPI, and temporal resolution (the ability to separate cardiac- and respiration-related fluctuations from the desired blood oxygen level-dependent signal of interest). RESULTS: Whole brain images with a nominal voxel size of 2 mm isotropic could be acquired with a temporal resolution under half a second using traditional parallel imaging acceleration up to 4× in the partition-encode direction and using novel data acquisition speed-up of 2× with a 32-channel coil. With 8× data acquisition speed-up in the partition-encode direction, 3D reduced excitations (RE)-EPI produced acceptable image quality without introduction of noticeable additional artifacts. Due to increased tSNR and better characterization of physiological fluctuations, the new strategy allowed detection of more resting state networks compared with multislice 2D-EPI and segmented 3D EPI. CONCLUSION: 3D RE-EPI resulted in significant increases in temporal resolution for whole brain acquisitions and in improved physiological noise characterization compared with 2D-EPI and segmented 3D EPI. Magn Reson Med 72:786-792, 2014. © 2013 Wiley Periodicals, Inc.

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The mature ooxysts of six new species of Caryospora are described from the faeces of Brazilian snakes. They are differentiated from other species previously recorded from reptiles, largely on the size and shape of the oocyst and sporocyst, structure of the oocyst wall, and presence or absence of a polar body. C. paraensis n. sp., and C. carajasensis n. sp., are from the "false coral", Oxyrhopus petola digitalis; C. pseustesi n. sp., from the "egg-eater", Pseustes sulphureus sulphureus; C. epicratesi n. sp., from the "red boa", Epicrates cenchria cenchria; and C. micruri n. sp., and C. constancieae n. sp., from the "coral snake", Micrurus spixii spixii. A re-description is given of C. jararacae Carini, 1939, from the "jararaca" Bothrops atrox, embodying some additional morphological features.

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The idea of Chineseness as a geographic, cultural-specific and ethnically-charged concept, and the pivotal role assumed by memory linger throughout the writings of most authors hailing from Chinese community in Southeast Asia. Among these communities, being the Malaysian Chinese the more prolific in terms of number of writers and pieces of literature produced, this paper deals specifically with it. Its focus is put on the literature produced by Malaysian Chinese authors residing in Taiwan, which topic constitutes an important part of the first chapter, and on one of its main representatives, Ng Kim Chew, to whom chapter two and three are fully dedicated. A literary analysis of one of his short stories, Huo yu tu, will allow the reader to have a first-hand experience, through excerpts from the original text, of the importance of Chineseness and memory in the literary production of Ng and of many authors sharing with him similar life and literary experiences. I started this research from the assumption that these authors make large use of their own memories and memories from their own community in their writing as a way to re-tie themselves to the Chineseness they left in their places of origin. However in the case of Ng Kim Chew, the analysis of his works led be to theorizing that the identity he is imbued with, if there is one, is not Chinese, nor Malaysian, but purely and distinctively Malaysian-Chinese. This paper can also serve as an introduction for the general public to the field of Sinophone literature from Southeast Asia and to promote wider and innovative paths of research within the realm of Chinese studies that go beyond China proper.

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