146 research outputs found
Evolution of the documents related to the study of taekwondo sports performance: a bibliometric review
Abstract: Taekwondo is a Korean martial art, combat sport, and Olympic discipline. Taekwondo competition is characterized as an
individual sport (1X1), single elimination tournament and repechage system. The aim goal of this study is brought of a bibliometric
review regarding the item’s “taekwondo” and “performance”, through identified and published manuscripts on the Web of Science
(WOS) database by December 31, 2022. The bibliometric analysis was used to analyze a data set of 460 WOS-indexed manuscripts
published between 1992 and 2022. Descriptive analysis, citation, authorships, countries, institutionals, and keywords co-occurrence
analyses were conducted into Taekwondo sports performance. The manuscripts founded in the WOS database are inserted on the
categories: “Sports Science” (n = 229), “Hospitality Leisure Sport Tourism” (n = 48), and “Physiology” (n = 32). The authors Kazemi
et al. (2006), Matsushigue et al. (2009), and Paillard (2017) are the must published and cited researchers. The countries with high
number of published manuscripts with the objective of this study are Brazil (n = 83), South Korea (n = 57), and Spain (n = 52). We
found also, five collaboration networks between authors and institutions, found a gap of the thematic relevant researchers. The
authors should have highlighted Franchini, E., (n = 42), and Falco, C., (n = 20). It is recommended to carry out multidimensional
research on Taekwondo sports performance with the aim of establishing collaborations within groups, institutions, and countries.
In this way, the productivity, effectiveness, and quality of research would be increased, as well as international collaboration
networks.info:eu-repo/semantics/publishedVersio
Effects of Orifice Sizes for Uncontrolled Filling Processes in Water Pipelines
[EN] The sizing of air valves during the air expulsion phase in rapid filling processes is crucial for design purposes. Mathematical models have been developed to simulate the behaviour of air valves during filling processes for air expulsion, utilising 1D and 2D schemes. These transient events involve the presence of two fluids with different properties and behaviours (water and air). The effect of air valves under scenarios of controlled filling processes has been studied by various authors; however, the analysis of uncontrolled filling processes using air valves has not yet been considered. In this scenario, water columns reach high velocities, causing part of them to close air valves, which generates an additional peak in air pocket pressure patterns. In this research, a two-dimensional computational fluid dynamics model is developed in OpenFOAM software to simulate the studied situations.Aguirre-Mendoza, AM.; Paternina-Verona, DA.; Oyuela, S.; Coronado-Hernández, OE.; Besharat, M.; Fuertes-Miquel, VS.; Iglesias Rey, PL.... (2022). Effects of Orifice Sizes for Uncontrolled Filling Processes in Water Pipelines. Water. 14(6):1-11. https://doi.org/10.3390/w1406088811114
Election turnout statistics in many countries: similarities, differences, and a diffusive field model for decision-making
We study in details the turnout rate statistics for 77 elections in 11
different countries. We show that the empirical results established in a
previous paper for French elections appear to hold much more generally. We find
in particular that the spatial correlation of turnout rates decay
logarithmically with distance in all cases. This result is quantitatively
reproduced by a decision model that assumes that each voter makes his mind as a
result of three influence terms: one totally idiosyncratic component, one
city-specific term with short-ranged fluctuations in space, and one long-ranged
correlated field which propagates diffusively in space. A detailed analysis
reveals several interesting features: for example, different countries have
different degrees of local heterogeneities and seem to be characterized by a
different propensity for individuals to conform to the cultural norm. We
furthermore find clear signs of herding (i.e. strongly correlated decisions at
the individual level) in some countries, but not in others.Comment: 15 pages, 9 figures, 7 table
Surface Morphology Evolution of Chemical Vapor-Deposited Tungsten Films on Si(100)
Chemical vapor deposition (CVD) is used to prepare research-grade heterostructures and to produce the majority of industrially important thin films.[1] In particular, CVD tungsten films are used for many technological applications.[2,3] In CVD an external source maintains a fixed concentration of reactant molecules at a distance above the film surface.[4] Then, gas diffusion drives the molecules through the diffusion layer[2] towards the film surface. At the film interface a reaction must occur before new material is incorporated into the solid. Kinetic studies show that two growth regimes are usually present in CVD. At a low deposition temperature (low rate, regime I) the kinetics is controlled by the surface reaction, whereas at a high temperature (high rate, regime II), mass transport of reactants to, or reaction products from, the surface is the rate-controlling step.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada
Noise-assisted energy transport in electrical oscillator networks with off-diagonal dynamical disorder
Noise is generally thought as detrimental for energy transport in coupled oscillator networks. However, it has been shown that for certain coherently evolving systems, the presence of noise can enhance, somehow unexpectedly, their transport efficiency; a phenomenon called environment-assisted quantum transport (ENAQT) or dephasing-assisted transport. Here, we report on the experimental observation of such effect in a network of coupled electrical oscillators. We demonstrate that by introducing stochastic fluctuations in one of the couplings of the network, a relative enhancement in the energy transport efficiency of 22.5 ± 3.6% can be observed.Peer ReviewedPostprint (published version
Severe manifestations of SARS-CoV-2 in children and adolescents: from COVID-19 pneumonia to multisystem inflammatory syndrome: a multicentre study in pediatric intensive care units in Spain
Background
Multisystem inflammatory syndrome temporally associated with COVID-19 (MIS-C) has been described as a novel and often severe presentation of SARS-CoV-2 infection in children. We aimed to describe the characteristics of children admitted to Pediatric Intensive Care Units (PICUs) presenting with MIS-C in comparison with those admitted with SARS-CoV-2 infection with other features such as COVID-19 pneumonia.
Methods
A multicentric prospective national registry including 47 PICUs was carried out. Data from children admitted with confirmed SARS-CoV-2 infection or fulfilling MIS-C criteria (with or without SARS-CoV-2 PCR confirmation) were collected. Clinical, laboratory and therapeutic features between MIS-C and non-MIS-C patients were compared.
Results
Seventy-four children were recruited. Sixty-one percent met MIS-C definition. MIS-C patients were older than non-MIS-C patients (p = 0.002): 9.4 years (IQR 5.5–11.8) vs 3.4 years (IQR 0.4–9.4). A higher proportion of them had no previous medical history of interest (88.2% vs 51.7%, p = 0.005). Non-MIS-C patients presented more frequently with respiratory distress (60.7% vs 13.3%, p < 0.001). MIS-C patients showed higher prevalence of fever (95.6% vs 64.3%, p < 0.001), diarrhea (66.7% vs 11.5%, p < 0.001), vomits (71.1% vs 23.1%, p = 0.001), fatigue (65.9% vs 36%, p = 0.016), shock (84.4% vs 13.8%, p < 0.001) and cardiac dysfunction (53.3% vs 10.3%, p = 0.001). MIS-C group had a lower lymphocyte count (p < 0.001) and LDH (p = 0.001) but higher neutrophil count (p = 0.045), neutrophil/lymphocyte ratio (p < 0.001), C-reactive protein (p < 0.001) and procalcitonin (p < 0.001). Patients in the MIS-C group were less likely to receive invasive ventilation (13.3% vs 41.4%, p = 0.005) but were more often treated with vasoactive drugs (66.7% vs 24.1%, p < 0.001), corticosteroids (80% vs 44.8%, p = 0.003) and immunoglobulins (51.1% vs 6.9%, p < 0.001). Most patients were discharged from PICU by the end of data collection with a median length of stay of 5 days (IQR 2.5–8 days) in the MIS-C group. Three patients died, none of them belonged to the MIS-C group.
Conclusions
MIS-C seems to be the most frequent presentation among critically ill children with SARS-CoV-2 infection. MIS-C patients are older and usually healthy. They show a higher prevalence of gastrointestinal symptoms and shock and are more likely to receive vasoactive drugs and immunomodulators and less likely to need mechanical ventilation than non-MIS-C patients
Prognostic Value of Serum Paraprotein Response Kinetics in Patients With Newly Diagnosed Multiple Myeloma
Response kinetics is not well-established as a prognostic marker in multiple myeloma (MM). We developed a mathematical model to assess the prognostic value of serum monoclonal component (MC) response kinetics during 6 induction cycles in 373 newly diagnosed MM patients. The model calculated a resistance parameter that reflects the stagnation in the response after an initial descent, dividing the patients into two kinetics categories with significantly different progression-free survival (PFS). Introduction: Response kinetics is a well-established prognostic marker in acute lymphoblastic leukemia. The situation is not clear in multiple myeloma (MM) despite having a biomarker for response monitoring (monoclonal component [MC]). Materials and Methods: We developed a mathematical model to assess the prognostic value of serum MC response kinetics during 6 induction cycles, in 373 NDMM transplanted patients treated in the GEM2012Menos65 clinical trial. The model calculated a resistance parameter that reflects the stagnation in the response after an initial descent. Results: Two patient subgroups were defined based on low and high resistance, that respectively captured sensitive and refractory kinetics, with progression-free survival (PFS) at 5 years of 72% and 59% (HR 0.64, 95% CI 0.44-0.93; P =.02). Resistance significantly correlated with depth of response measured after consolidation (80.9% CR and 68.4% minimal residual disease negativity in patients with sensitive vs. 31% and 20% in those with refractory kinetics). Furthermore, it modulated the impact of reaching CR after consolidation; thus, within CR patients those with refractory kinetics had significantly shorter PFS than those with sensitive kinetics (median 54 months vs. NR; P =.02). Minimal residual disease negativity abrogated this effect. Our study also questions the benefit of rapid responders compared to late responders (5-year PFS 59.7% vs. 76.5%, respectively [P <.002]). Of note, 85% of patients considered as late responders were classified as having sensitive kinetics. Conclusion: This semi-mechanistic modeling of M-component kinetics could be of great value to identify patients at risk of early treatment failure, who may benefit from early rescue intervention strategies. (C) 2022 The Authors. Published by Elsevier Inc
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