807 resultados para Hold


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The principle of equal political representation can be undermined by differences in economic resources among citizens. Poor citizens are likely to hold policy preferences that differ from those of richer citizens. At the same time, their lack of resources can have as a consequence that these preferences are not taken into consideration by their representatives. Focusing on the case of the Swiss Parliament and using survey data on the opinions of citizens and MPs in the 2007-2011 legislature, this study investigates whether the income of citizens systematically affects the proximity of their policy preferences with stances of their representatives. It demonstrates that on economic issues MPs hold preferences that are generally less in favour of the state's intervention in the economy than the median citizen and that relatively poor citizens are less well represented as compared to citizens with high incomes. This remains true when taking into account only the opinions of the most knowledgeable citizens among these groups as well as when the focus is only on those who turned out to vote.

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It has been long stated that there are profound analogies between fracture experiments and earthquakes; however, few works attempt a complete characterization of the parallelisms between these so separate phenomena. We study the Acoustic Emission events produced during the compression of Vycor (SiO&sub&2&/sub&). The Gutenberg-Richter law, the modified Omori's law, and the law of aftershock productivity hold for a minimum of 5 decades, are independent of the compression rate, and keep stationary for all the duration of the experiments. The waiting-time distribution fulfills a unified scaling law with a power-law exponent close to 2.45 for long times, which is explained in terms of the temporal variations of the activity rate.

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OBJECTIVE: An inverse relationship between blood pressure (BP) and cognitive function has been found in adults, but limited data are available in adolescents and young adults. We examined the prospective relation between BP and cognitive function in adolescence. METHODS: We examined the association between BP measured at the ages of 12-15 years in school surveys and cognitive endpoints measured in the Seychelles Child Development Study at ages 17 (n = 407) and 19 (n = 429) years, respectively. We evaluated multiple domains of cognition based on subtests of the Cambridge Neurological Test Automated Battery (CANTAB), the Woodcock Johnson Test of Scholastic Achievement (WJTA), the Finger Tapping test (FT) and the Kaufman Brief Intelligence Test (K-BIT). We used age, sex and height-specific z-scores of SBP, DBP and mean arterial pressure (MAP). RESULTS: Six out of the 21 cognitive endpoints tested were associated with BP. However, none of these associations were found to hold for both males and females or for different subtests within the same neurodevelopmental domain or for both SBP and DBP. Most of these associations disappeared when analyses were adjusted for selected potential confounding factors such as socio-economic status, birth weight, gestational age, BMI, alcohol consumption, blood glucose, and total n-3 and n-6 polyunsaturated fats. CONCLUSIONS: Our findings do not support a consistent association between BP and subsequent performance on tests assessing various cognitive domains in adolescents.

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Background: Chronic venous insufficiency (CVI) represents a major global health problem with increasing prevalence and morbidity. CVI is due to an incompetence of the venous valves, which causes venous reflux and distal venous hypertension. Several studies have focused on the replacement of diseased venous valves using xeno- and allogenic transplants, so far with moderate success due to immunologic and thromboembolic complications. Autologous cell-derived tissue-engineered venous valves (TEVVs) based on fully biodegradable scaffolds could overcome these limitations by providing non-immunogenic, non-thrombogenic constructs with remodeling and growth potential. Methods: Tri- and bicuspid venous valves (n=27) based on polyglycolic acid-poly-4-hydroxybutyrate composite scaffolds, integrated into self-expandable nitinol stents, were engineered from autologous ovine bone-marrow-derived mesenchymal stem cells (BM-MSCs) and endothelialized. After in vitro conditioning in a (flow) pulse duplicator system, the TEVVs were crimped (n=18) and experimentally delivered (n=7). The effects of crimping on the tissue-engineered constructs were investigated using histology, immunohistochemistry, scanning electron microscopy, grating interferometry (GI), and planar fluorescence reflectance imaging. Results: The generated TEVVs showed layered tissue formation with increasing collagen and glycosaminoglycan levels dependent on the duration of in vitro conditioning. After crimping no effects were found on the MSC level in scanning electron microscopy analysis, GI, histology, and extracellular matrix analysis. However, substantial endothelial cell loss was detected after the crimping procedure, which could be reduced by increasing the static conditioning phase. Conclusions: Autologous living small-diameter TEVVs can be successfully fabricated from ovine BM-MSCs using a (flow) pulse duplicator conditioning approach. These constructs hold the potential to overcome the limitations of currently used non-autologous replacement materials and may open new therapeutic concepts for the treatment of CVI in the future.

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Black-blood MR coronary vessel wall imaging may become a powerful tool for the quantitative and noninvasive assessment of atherosclerosis and positive arterial remodeling. Although dual-inversion recovery is currently the gold standard, optimal lumen-to-vessel wall contrast is sometimes difficult to obtain, and the time window available for imaging is limited due to competing requirements between blood signal nulling time and period of minimal myocardial motion. Further, atherosclerosis is a spatially heterogeneous disease, and imaging at multiple anatomic levels of the coronary circulation is mandatory. However, this requirement of enhanced volumetric coverage comes at the expense of scanning time. Phase-sensitive inversion recovery has shown to be very valuable for enhancing tissue-tissue contrast and for making inversion recovery imaging less sensitive to tissue signal nulling time. This work enables multislice black-blood coronary vessel wall imaging in a single breath hold by extending phase-sensitive inversion recovery to phase-sensitive dual-inversion recovery, by combining it with spiral imaging and yet relaxing constraints related to blood signal nulling time and period of minimal myocardial motion.

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Many firms around the world are managed and partially owned by entrepreneurs. These entrepreneurs hold under diversified portfolios and, therefore, bear idiosyncratic risk in addition to systematic risk. To compensate the additional risk borne, they extract private benefits. In this paper, we analyse how an entrepreneur's overconfidence affects the market performance of the firm, through the channel of private benefits. We show that two dimensions of overconfidence, namely overestimation of future cash-flows and underestimation of idiosyncratic risk (called miscalibration), have opposite effects on the private benefits extracted by the entrepreneur. As a consequence, firms managed and partially owned by overconfident entrepreneurs can deliver overperformance or underperformance, depending on the prevalence of overestimation or miscalibration of the beliefs of the entrepreneur.

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In the present study, complementary spatial modulation of magnetization (CSPAMM) myocardial tagging was extended with an interleaved spiral imaging sequence. The use of a spiral sequence enables the acquisition of grid-tagged images with a tagline distance as low as 4 mm in a single breath-hold. Alternatively, a high temporal resolution of 77 frames per second was obtained with 8-mm grid spacing. Ten healthy adult subjects were studied. With this new approach, high-quality images can be obtained and the tags persist throughout the entire cardiac cycle.

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Discussions at the inaugural meeting of a Trans-European Pedagogic Research Group for Anatomical Sciences highlighted the fact that there exist considerable variations in the legal and ethical frameworks throughout Europe concerning body bequests for anatomical examination. Such differences appear to reflect cultural and religious variations as well as different legal and constitutional frameworks. For example, there are different views concerning the "ownership" of cadavers and concerning the need (perceived by different societies and national politicians) for legislation specifically related to anatomical dissection. Furthermore, there are different views concerning the acceptability of using unclaimed bodies that have not given informed consent. Given that in Europe there have been a series of controversial anatomical exhibitions and also a public (televised) dissection/autopsy, and given that the commercial sale or transport of anatomical material across national boundaries is strongly debated, it would seem appropriate to "harmonise" the situation (at least in the European Union). This paper summarises the legal situation in a variety of European countries and suggests examples of good practice. In particular, it recommends that all countries should adopt clear legal frameworks to regulate the acceptance of donations for medical education and research. It stresses the need for informed consent, with donors being given clear information upon which to base their decision, intentions to bequest being made by the donor before death and encourages donors to discuss their wishes to bequeath with relatives prior to death. Departments are encouraged, where they feel it appropriate, to hold Services of Thanksgiving and Commemoration for those who have donated their bodies. Finally, there needs to be legislation to regulate transport of bodies or body parts across national borders and a discouragement of any moves towards commercialisation in relation to bequests.

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This paper analyzes the implications of pre-trade transpareny on market performance. We find that transparency increases the precision held by agents, however we show that this increase in precision may not be due to prices themselves. In competitive markets, transparency increases market liquidity and reduces price volatility, whereas these results may not hold under imperfect competition. More importantly, market depth and volatility might be positively related with proper priors. Moreover, we study the incentives for liquidity traders to engage in sunshine trading. We obtain that the choice of sunshine/dark trading for a noise trader is independent of his order size, being the traders with higher liquidity needs more interested in sunshine trading, as long as this practice is desirable. Key words: Market Microstructure, Transparency, Prior Information, Market Quality, Sunshine Trading

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In schizophrenia, a developmental redox dysregulation constitutes one 'hub' on which converge genetic impairments of glutathione synthesis and environmental vulnerability factors generating oxidative stress. Their timing at critical periods of neurodevelopment could play a decisive role in inducing impairment of neural connectivity and synchronization as observed in schizophrenia. In experimental models, such redox dysregulation induces anomalies strikingly similar to those observed in patients. This is mediated by hypoactive NMDA receptors, impairment of fast-spiking parvalbumin GABA interneurons and deficit in myelination. A treatment restoring the redox balance without side effects yields improvements of negative symptoms in chronic patients. Novel interventions based on these mechanisms if applied in early phases of the disease hold great therapeutic promise.

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The behaviour of a new elastoplastic shear link dissipator has been analysed in the first part of this paper. The second part describes experimental and numerical studies for a SDOF non-standard dual system protected with shear dissipators. High and intermediate stiff deal systems with this Device have presented smaller values of the shear base force and the interstory drift when compared to linear and elastic systems response. It has been appreciated that most of introduced energy is dissipated when a low ratio between the main frame stiffness and dissipation system stiffness is hold. It has been also observed that a higher ratio between the dissipator yielding force and the total mass drives to a more reduced structural response. Finally is has been appreciated than the absorbed energy might be predicted using the velocity pseudo-spectra and an effective fundamental period, that has been defined by using the minimum secant stiffness of dual system

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Estudi realitzat a partir d’una estada al Laboratoire d’études sur les monothéismes (UMR 8584, Centre national de la recherche scientifique / École pratique des hautes études / Université Paris IV-Sorbonne), França, entre 2010 i 2011. Anàlisi de la crisi estructural que afectà a l’església gal•la entre el darrer quart del segle IV i el primer del segle VI, crisi causada per la cristianització a gran escala de les elits aristocràtiques gal•loromanes i per la reivindicació per part d’aquest estament de la translació a l’esfera de la jerarquia institucional de l’Església de la seva preeminència econòmica i social. Aquest procés implicà l’aparició d’algunes interpretacions del “fet existencial cristià” que tractaven de legitimar en el plànol teòric la presa del control de les comunitats cristianes per part de la noblesa senatorial. En relació a aquest últim punt, s’ha donat particular rellevància a l’anomenada “controvèrsia semipelagiana” a Provença, amb especial èmfasi en dos punts: a) la relació entre l’oposició a la teologia agustiniana de la gràcia en alguns cercles monàstics provençals –Marsella, Lérins– i l’emergència en aquests ambients d’una literatura autobiogràfica en la que la reflexió sobre els conceptes de uocatio divina i conuersio a l’ascetisme cristià està estretament vinculada a un esforç teòric de redefinició i reorientació de l’ethos aristocràtic; i b) la relació entre els punts teològics debatuts en aquesta controvèrsia i les concepcions eclesiològiques dels pensadors que hi prengueren part –entengui’s aquí per eclesiologia la definició teòrica dels límits i dels fonaments de la “comunitat cristiana”, amb especial incidència en aquest cas en els plantejaments sobre el rol que l’aristòcrata havia d’exercir en aquestes noves comunitats “transversals”–. Aquest projecte bianual ha posat de manifest la inexistència d’una “teologia semipelagiana”, ateses les antagòniques concepcions eclesiològiques dels autors tradicionalment associats a aquesta corrent de pensament: Cassià entén la comunitat cristiana com una elit ascètica en la que els criteris “laics” d’estratificació social queden suspesos, i rebutja –en la teoria i en la pràctica– que aquesta elit hagi d’assumir el lideratge de la comunitat de fidels seglars; en els autors del cercle de Lérins, en canvi, l’oposició a la teologia agustiniana de la gràcia és inspirada per l’esforç d’importar a tota la comunitat cristiana els ideals monàstics, quelcom que fou també una via de legitimació de l’autoritat dels monjos-bisbes d’origen aristocràtic sorgits del cenobi de Lérins.

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Richer and healthier agents tend to hold riskier portfolios and spend proportionally less on health expenditures. Potential explanations include health and wealth effects on preferences, expected longevity or disposable total wealth. Using HRS data, we perform a structural estimation of a dynamic model of consumption, portfolio and health expenditure choices with recursive utility, as well as health-dependent income and mortality risk. Our estimates of the deep parameters highlight the importance of health capital, mortality risk control, convex health and mortality adjustment costs and binding liquidity constraints to rationalize the stylized facts. They also provide new perspectives on expected longevity and on the values of life and health.

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The generation of induced pluripotent stem (iPS) cells has enabled the derivation of patient-specific pluripotent cells andprovided valuable experimental platforms to model human disease. Patient-specific iPS cells are also thought to hold greattherapeutic potential, although direct evidence for this is still lacking. Here we show that, on correction of the genetic defect,somatic cells from Fanconi anaemia patients can be reprogrammed to pluripotency to generate patient-specific iPS cells. These cell lines appear indistinguishable from human embryonic stem cells and iPS cells from healthy individuals. Most importantly, we show that corrected Fanconi-anaemia-specific iPS cells can give rise to haematopoietic progenitors of the myeloid and erythroid lineages that are phenotypically normal, that is, disease-free. These data offer proof-of-concept that iPS cell technology can be used for the generation of disease-corrected, patient-specific cells with potential value for cell therapy applications.

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In the context of fading channels it is well established that, with a constrained transmit power, the bit rates achievable by signals that are not peaky vanish as the bandwidth grows without bound. Stepping back from the limit, we characterize the highest bit rate achievable by such non-peaky signals and the approximate bandwidth where that apex occurs. As it turns out, the gap between the highest rate achievable without peakedness and the infinite-bandwidth capacity (with unconstrained peakedness) is small for virtually all settings of interest to wireless communications. Thus, although strictly achieving capacity in wideband fading channels does require signal peakedness, bit rates not far from capacity can be achieved with conventional signaling formats that do not exhibit the serious practical drawbacks associated with peakedness. In addition, we show that the asymptotic decay of bit rate in the absence of peakedness usually takes hold at bandwidths so large that wideband fading models are called into question. Rather, ultrawideband models ought to be used.