1,974 research outputs found

    Institutions and Growth in Europe. CEPS Working Document No. 421, April 2016

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    This paper provides empirical evidence in support of the view that the quality of institutions is an important determinant of long-term growth of European countries. When also taking into account the initial level of GDP per capita and government debt, cross-country institutional differences can explain to a great extent the relative long-term GDP performance of European countries. It also shows that an initial government debt level above a threshold (e.g. 60-70%) coupled with institutional quality below the EU average tends to be associated with particularly poor long-term real growth performance. Interestingly, the detrimental effect of high debt levels on long-term growth seems cushioned by the presence of very sound institutions. This might be because good institutions help to alleviate the debt problem in various ways, e.g. by ensuring sufficient fiscal consolidation in the longer-run, allowing for better use of government expenditures and promoting sustainable growth, social fairness and more efficient tax administration. The quality of national institutions seems to enhance the long-term GDP performance across a large sample of countries, also including OECD countries outside Europe. The paper offers some evidence that, in the presence of good institutions, conditions for catching-up seem generally good also for euro-area and fixed exchange rate countries. Looking at sub-groupings, it seems that sound institutions may be particularly important for long-term growth in the countries where the exchange rate tool is no longer available (and where also sovereign debt is high), and less so in the countries with flexible exchange rate regimes. However, this result is preliminary and requires further research. The empirical findings on the importance of institutions are robust to various measures of output growth, different measures of institutional indicators, different sample sizes, different country groupings and to the inclusion of additional control variables. Overall, the results tend to support the call for structural reforms in general and reforms enhancing the efficiency of public administration and regulation, the rule of law and the fight against rent-seeking and corruption in particular

    A quality assurance phantom for electronic portal imaging devices

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    Electronic portal imaging device (EPID) plays an important role in radiation therapy portal imaging, geometric and dosimetric verification. Consistent image quality and stable radiation response is necessary for proper utilization that requires routine quality assurance (QA). A commercial ‘EPID QC’ phantom weighing 3.8 kg with a dimension of 25 × 25 × 4.8 cm3 is used for EPID QA. This device has five essential tools to measure the geometric accuracy, signal‐to‐noise ratio (SNR), dose linearity, and the low‐ and the high‐contrast resolutions. It is aligned with beam divergence to measure the imaging and geometric parameters in both X and Y directions, and can be used as a baseline check for routine QA. The low‐contrast tool consists of a series of holes with various diameters and depths in an aluminum slab, very similar to the Las Vegas phantom. The high‐resolution contrast tool provides the modulation transfer function (MTF) in both the x‐ and y‐dimensions to measure the focal spot of linear accelerator that is important for imaging and small field dosimetry. The device is tested in different institutions with various amorphous silicon imagers including Elekta, Siemens and Varian units. Images of the QA phantom were acquired at 95.2 cm source‐skin‐distance (SSD) in the range 1–15 MU for a 26 × 26 cm2 field and phantom surface is set normal to the beam direction when gantry is at 0° and 90°. The epidSoft is a software program provided with the EPID QA phantom for analysis of the data. The preliminary results using the phantom on the tested EPID showed very good low‐contrast resolution and high resolution, and an MTF (0.5) in the range of 0.3–0.4 lp/mm. All imagers also exhibit satisfactory geometric accuracy, dose linearity and SNR, and are independent of MU and spatial orientations. The epidSoft maintains an image analysis record and provides a graph of the temporal variations in imaging parameters. In conclusion, this device is simple to use and provides testing on basic and advanced imaging parameters for daily QA on any imager used in clinical practice

    Institutions, public debt and growth in Europe

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    This paper provides empirical evidence that supports the view that the quality of institutions is an important determinant of long-term growth in European countries. It shows that an initial high government debt level coupled with institutional quality below the EU average tends to be associated with particularly poor longterm real growth performance. Interestingly, the detrimental effect of high debt levels on long-term growth seems cushioned by the presence of very sound institutions. The paper offers some evidence that sound institutions may be particularly important for long-term growth in countries in which the exchange rate tool is no longer available and less so in countries with flexible exchange rate regimes. The empirical findings on the importance of institutions are robust to various measures of output growth, different measures of institutional indicators, different sample sizes, different country groupings and to the inclusions of additional control variables

    Исследование влияния динамических режимов нагружения на вибрационные характеристики узлов трения вращательного и возвратно-вращательного действия

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    Цель работы – определение влияния вибрационной составляющей на точность воспроизведения динамических законов нагружения и триботехнические характеристики узла трения при его испытании на автоматизированном триботехническом комплексе. В процессе исследования проводились: аналитический обзор существующих методов и аппаратно-программного обеспечение для исследования и анализа виброакустических сигналов, построение математической модели узла скоростного динамического нагружения, разработка комплекса контрольно-измерительного оборудования, разработка программного обеспечения, определение способов крепления и мест установки первичных вибропреобразователей, а также анализ виброакустических сигналов.During the process of writing the graduate qualification work, the following tasks have been achived: 1.Integrated instrument development for the investigation of vibroacoustics; 2. Compiling a numerical scheme; 3. Software development for the imagery of vibroacoustics; 4. Investigation of vibroacoustics

    Interpreting Quality of Life after Brain Injury (QOLIBRI) scores: Cross-walk with the Short Form-36

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    The Quality of Life after Brain Injury (QOLIBRI) instruments are traumatic brain injury-specific assessments of health-related quality of life (HRQoL), with established validity and reliability. The purpose of the study is to help improve the interpretability of the two QOLIBRI summary scores (the QOLIBRI Total score and the QOLBRI Overall Scale score). An analysis was conducted of 761 patients with traumatic brain injury (TBI) that took part in the QOLIBRI validation studies. A cross-walk between QOLIBRI scores and the SF-36 Mental Component Summary norm-based scoring system was performed using geometric mean regression analysis. The exercise supports a previous suggestion that QOLIBRI Total scores < 60 indicate low or impaired HRQoL, and indicate that the corresponding score on the QOLIBRI-OS is <52. The percentage of cases in the sample that fell into the ‘impaired HRQoL’ category were 36% for the Mental Component Summary, 38% for the QOLIBRI Total, and 39% for the QOLIBRI-OS. Relationships between the QOLIBRI scales and the Glasgow Outcome Scale – Extended (GOSE), as a measure of global function, are presented in the form of means and standard deviations that allow comparison with other studies, and data on age and gender are presented for the QOLIBRI-OS. While bearing in mind the potential imprecision of the comparison, the findings provide a framework for evaluating QOLIBRI summary scores in relation to generic HRQoL that improves their interpretability

    Assessment of Health-Related Quality of Life after TBI: Comparison of a Disease-Specific (QOLIBRI) with a Generic (SF-36) Instrument

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    Psychosocial, emotional, and physical problems can emerge after traumatic brain njury (TBI), potentially impacting health-related quality of life (HRQoL). Until now, however, neither the discriminatory power of disease-specific (QOLIBRI) and generic (SF-36) HRQoL nor their correlates have been compared in detail. These aspects as well as some psychometric item characteristics were studied in a sample of 795 TBI survivors. The Shannon H耠 index absolute informativity, as an indicator of an instrument’s power to differentiate between individualswithin a specific group or health state,was investigated. Psychometric performance of the two instruments was predominantly good, generally higher, and more homogenous for the QOLIBRI than for the SF-36 subscales. Notably, the SF-36 “Role Physical,” “Role Emotional,” and “Social Functioning” subscales showed less satisfactory discriminatory power than all other dimensions or the sum scores of both instruments. The absolute informativity of disease-specific as well as generic HRQoL instruments concerning the different groups defined by different correlates differed significantly.When the focus is on how a certain subscale or sum score differentiates between individuals in one specific dimension/health state, the QOLIBRI can be recommended as the preferable instrument.Psychosocial, emotional, and physical problems can emerge after traumatic brain injury (TBI), potentially impacting health-related quality of life (HRQoL). Until now, however, neither the discriminatory power of disease-specific (QOLIBRI) and generic (SF-36) HRQoL nor their correlates have been compared in detail. These aspects as well as some psychometric item characteristics were studied in a sample of 795 TBI survivors. The Shannon H耠 index absolute informativity, as an indicator of an instrument’s power to differentiate between individualswithin a specific group or health state,was investigated. Psychometric performance of the two instruments was predominantly good, generally higher, and more homogenous for the QOLIBRI than for the SF-36 subscales. Notably, the SF-36 “Role Physical,” “Role Emotional,” and “Social Functioning” subscales showed less satisfactory discriminatory power than all other dimensions or the sum scores of both instruments. The absolute informativity of disease-specific as well as generic HRQoL instruments concerning the different groups defined by different correlates differed significantly.When the focus is on how a certain subscale or sum score differentiates between individuals in one specific dimension/health state, the QOLIBRI can be recommended as the preferable instrument.Peer reviewe

    HIVconsv Vaccines and Romidepsin in Early-Treated HIV-1-Infected Individuals: Safety, Immunogenicity and Effect on the Viral Reservoir (Study BCN02)

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    Kick&kill strategies combining drugs aiming to reactivate the viral reservoir with therapeutic vaccines to induce effective cytotoxic immune responses hold potential to achieve a functional cure for HIV-1 infection. Here, we report on an open-label, single-arm, phase I clinical trial, enrolling 15 early-treated HIV-1-infected individuals, testing the combination of the histone deacetylase inhibitor romidepsin as a latency-reversing agent and the MVA.HIVconsv vaccine. Romidepsin treatment resulted in increased histone acetylation, cell-associated HIV-1 RNA, and T-cell activation, which were associated with a marginally significant reduction of the viral reservoir. Vaccinations boosted robust and broad HIVconsv-specific T cells, which were strongly refocused toward conserved regions of the HIV-1 proteome. During a monitored ART interruption phase using plasma viral load over 2,000 copies/ml as a criterium for ART resumption, 23% of individuals showed sustained suppression of viremia up to 32 weeks without evidence for reseeding the viral reservoir. Results from this pilot study show that the combined kick&kill intervention was safe and suggest a role for this strategy in achieving an immune-driven durable viremic control

    Shared genetic background between children and adults with attention deficit/hyperactivity disorder

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    Attention deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by age-inappropriate symptoms of inattention, impulsivity, and hyperactivity that persist into adulthood in the majority of the diagnosed children. Despite several risk factors during childhood predicting the persistence of ADHD symptoms into adulthood, the genetic architecture underlying the trajectory of ADHD over time is still unclear. We set out to study the contribution of common genetic variants to the risk for ADHD across the lifespan by conducting meta-analyses of genome-wide association studies on persistent ADHD in adults and ADHD in childhood separately and jointly, and by comparing the genetic background between them in a total sample of 17,149 cases and 32,411 controls. Our results show nine new independent loci and support a shared contribution of common genetic variants to ADHD in children and adults. No subgroup heterogeneity was observed among children, while this group consists of future remitting and persistent individuals. We report similar patterns of genetic correlation of ADHD with other ADHD-related datasets and different traits and disorders among adults, children, and when combining both groups. These findings confirm that persistent ADHD in adults is a neurodevelopmental disorder and extend the existing hypothesis of a shared genetic architecture underlying ADHD and different traits to a lifespan perspective
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