Search results for "204"
showing 10 items of 5248 documents
Active commuting to school among 36,781 Spanish children and adolescents: A temporal trend study.
2021
This study examines trends in the rates of active commuting to school (ACS) in Spanish children (n = 18 343; 8.93 ± 1.68) and adolescents (n = 18 438; 14.11 ± 1.58) aged 6‐18 years from 2010 to 2017. Given the study period included the economic crisis in Spain (2008‐2013), the second aim of this study was to compare ACS rates during and after the economic crisis. Data were obtained from 28 studies conducted across Spain. The overall trends in ACS were evaluated using multilevel logistic regression analysis. Among Spanish children and adolescents, the rates of ACS to school ranged around 60% between 2010 and 2017. The rates of ACS in Spanish youth did not change significantly during the 2010…
Psoriasis and Its Impact on In-Hospital Outcome in Patients Hospitalized with Acute Kidney Injury
2020
Background: Psoriasis is a chronic inflammatory disease which affects the body far beyond the skin. Whereas there is solid evidence that chronic skin inflammation in psoriasis drives cardiovascular disease, the impact on renal impairment and acute kidney injury (AKI) is still unclear. We aimed to analyze the impact of psoriasis on the in-hospital outcome of patients hospitalized with AKI. Methods: In this retrospective database study, we investigated data on characteristics, comorbidities, and in-hospital outcomes for all hospitalized patients with AKI stratified for concomitant psoriasis, which were collected by the Federal Office of Statistics in Germany between 2005 and 2016. Results: Am…
Parametric sensitivity of a CFD model concerning the hydrodynamics of trickle-bed reactor (TBR)
2016
Abstract The aim of the present study was to investigate the sensitivity of a multiphase Eulerian CFD model with respect to relations defining drag forces between phases. The mean relative error as well as standard deviation of experimental and computed values of pressure gradient and average liquid holdup were used as validation criteria of the model. Comparative basis for simulations was our own data-base obtained in experiments carried out in a TBR operating at a co-current downward gas and liquid flow. Estimated errors showed that the classical equations of Attou et al. (1999) defining the friction factors Fjk approximate experimental values of hydrodynamic parameters with the best agre…
Electronic Energy Meter Based on a Tunnel Magnetoresistive Effect (TMR) Current Sensor
2017
In the present work, the design and microfabrication of a tunneling magnetoresistance (TMR) electrical current sensor is presented. After its physical and electrical characterization, a wattmeter is developed to determine the active power delivered to a load from the AC 50/60 Hz mains line. Experimental results are shown up to 1000 W of power load. A relative uncertainty of less than 1.5% with resistive load and less than 1% with capacitive load was obtained. The described application is an example of how TMR sensing technology can play a relevant role in the management and control of electrical energy.
Prompt Determination of the Mechanical Properties of Industrial Polypropylene Sandwich Pipes
2021
A simple and prompt method to determine the mechanical properties of industrial multilayer extrusion polypropylene pipes for a gravity sewer network is suggested. The engineering formulas included for calculating the permissible thickness and relative position of a foam core in the pipes are based on a linear-elastic approximation and the rule of mixtures. The applicability of the approximation was justified experimentally during investigation of the effective tensile characteristics of single- and multilayer pipes and each layer specimen by using traditional tests and finite-element calculations. The results obtained were used to formulate engineering recommendations for calculations of th…
2020 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation
2020
2020 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation
Application of the Information Bottleneck method to discover user profiles in a Web store
2018
The paper deals with the problem of discovering groups of Web users with similar behavioral patterns on an e-commerce site. We introduce a novel approach to the unsupervised classification of user sessions, based on session attributes related to the user click-stream behavior, to gain insight into characteristics of various user profiles. The approach uses the agglomerative Information Bottleneck (IB) algorithm. Based on log data for a real online store, efficiency of the approach in terms of its ability to differentiate between buying and non-buying sessions was validated, indicating some possible practical applications of the our method. Experiments performed for a number of session sampl…
International Assessment Surveys of Educational Achievement in Developing Countries : Why Education Economists Should Care
2015
International audience; This paper reviews the most known international assessment studies that are conducted in the context of poor countries and highlights the lack of empirical evidence on the degree to which the contents of the tests really match countries' curricula. To illustrate, the paper evaluates the sensitivity of an international testing instrument by comparing the responses of students in two consecutive grades on the same battery of tests. Using propensity score matching to control for student and teacher characteristics, the results show that the tests are not grade sensitive, which raises the question of the validity of many empirical works that are based on similar instrume…
Comparison of inter-trial recovery times for the determination of critical power and W' in cycling
2017
Critical Power (CP) and W’ are often determined using multi-day testing protocols. To investigate this cumbersome testing method, the purpose of this study was to compare the differences between the conventional use of a 24-h inter-trial recovery time with those of 3 h and 30 min for the determination of CP and W’. Methods: 9 moderately trained cyclists performed an incremental test to exhaustion to establish the power output associated with the maximum oxygen uptake (p V O2max), and 3 protocols requiring time-to-exhaustion trials at a constant work-rate performed at 80%, 100% and 105% of p VO2max. Design: Protocol A utilised 24-h inter-trial recovery (CP24/W’24), protocol B utilised 3-h in…
Los saberes en torno a la tuberculosis en Valencia a través de la prensa médica (1882-1914)
2011
Para la realización de este trabajo se ha partido del interés que tiene estudiar la literatura científica que a finales del siglo XIX y principios del XX dedicó una sociedad como la valenciana al tema de la tuberculosis, de primera importancia no solo en la realidad epidemiológica de la época, sino también para la constitución de la ciencia y las prácticas médicas contemporáneas. Se ha abordado el estudio de los saberes en torno a la tuberculosis en Valencia a través de las revistas médicas publicadas en ella entre 1882 y 1914, periodo en el que se descubrió el origen microbiano de la enfermedad y se desarrollaron nuevas técnicas diagnósticas, preventivas y curativas de la infección tubercu…