1,600 research outputs found
Bilateral and Unilateral Asymmetries of Strength and Flexibility in Young Elite Sailors: Windsurfing, Optimist and Laser Classes
In sport sailing, performance is related to the sailor’s ability to maintain the stability of
the boat, and the boat class determines the variables involved in such ability. In monohull-type
vessels, such as the Optimist and Laser classes, the flexibility of the hip joint is a key performance
factor. In the Windsurfing class, performance is determined by the strength of the flexors of the
fingers and elbows. The performance of the sailor may be a ected by asymmetries in the strength
and flexibility of the muscles and joints involved in technical actions. The objective of this study
was to evaluate asymmetries in strength and flexibility in young sailors. Thirty-three young sailors
(ten girls) from the Windsurfing, Optimist and Laser classes were assessed for manual strength
and flexibility, by dynamometry and straight leg lift tests, respectively. The symmetry index and
the functional asymmetry of compression force were calculated. The results showed no di erences
between sailors according to gender. The sailors of the Laser class obtained the highest levels
of manual strength, whereas those of the Windsurfing class showed the highest flexibility levels.
The girls’ group andWindsurfing class had the highest percentage of sailors with strength asymmetry,
whereas, the sailors of the Optimist class presented a greater percentage of asymmetry in flexibility.
There were no di erences in upper limb strength and lower limb flexibility between the dominant
and non-dominant sides
Dynamics of a Self-interacting Scalar Field Trapped in the Braneworld for a Wide Variety of Self-interaction Potentials
We apply the dynamical systems tools to study the linear dynamics of a
self-interacting scalar field trapped in the braneworld, for a wide variety of
self-interaction potentials. We focus on Randall-Sundrum (RS) and on
Dvali-Gabadadze-Porrati (DGP) braneworld models exclusively. These models are
complementary to each other: while the RS brane produces ultra-violet (UV)
corrections to general relativity, the DGP braneworld modifies Einstein's
theory at large scales, i. e., produces infra-red (IR) modifications of general
relativity. This study of the asymptotic properties of both braneworld models,
shows -- in the phase space -- the way the dynamics of a scalar field trapped
in the brane departs from standard general relativity behaviour.Comment: 12 pages, 5 figures and 5 table
Temporal characterization of the requests to Wikipedia
This paper presents an empirical study about the temporal patterns
characterizing the requests submitted by users to Wikipedia.
The study is based on the analysis of the log lines registered by the
Wikimedia Foundation Squid servers after having sent the appropriate
content in response to users' requests. The
analysis has been conducted regarding the ten most visited editions of
Wikipedia and has involved more than 14,000 million log lines
corresponding to the traffic of the entire year 2009. The conducted methodology
has mainly consisted in the parsing and filtering
of users' requests according to the study directives. As a result, relevant information
fields have been finally stored in a database for persistence and further
characterization. In this way, we, first, assessed, whether the traffic to Wikipedia could serve
as a reliable estimator of the overall traffic to all the Wikimedia Foundation
projects. Our subsequent analysis of the temporal evolutions corresponding to
the different types of requests to Wikipedia revealed interesting differences
and similarities among them that can be related to the users' attention to the Encyclopedia.
In addition, we have performed separated characterizations of each Wikipedia edition
to compare their respective evolutions over time
A quantitative examination of the impact of featured articles in Wikipedia
This paper presents a quantitative examination of the impact of the presentation of featured articles as quality content in the main page of several Wikipedia editions. Moreover, the paper also presents the analysis performed to determine the number of visits received by the articles promoted to the featured status. We have analyzed the visits not only in the month when articles awarded the promotion or were included in the main page, but also in the previous and following ones. The main aim for this is to assess the attention attracted by the featured content and the different dynamics exhibited by each community of users in respect to the promotion process. The main results of this paper are twofold: it shows how to extract relevant information related to the use of Wikipedia, which is an emerging research topic, and it analyzes whether the featured articles mechanism achieve to attract more attention
The circular economy as a philosophy of the green economy as a strategy for social responsibility
[Resumo] O seguinte artigo mostra a importancia que ha ir adquirindo o coidado do medio ambiente por parte das organizacións industriais, xa que cada vez os recursos da natureza se volven máis escasos ao ser extraÃdos-procesados-usados-eliminados, polo que xurdiu unha filosofÃa chamada economÃa verde, que é a combinación de actividades económicas, pero sen danar ao medio ambiente. É aquà onde xorde o modelo de economÃa circular, como un sistema que busca a fabricación de produtos máis resistentes ou a recolección de materias primas a través da reciclaxe para a súa reutilización, o que representa unha forma de desenvolvemento sostible que mantén a responsabilidade social por parte das empresas.[Abstract] The following article shows the importance that has been acquiring the care to the environment by industrial organizations, given that the resources of nature are increasingly scarce when they are extracted - processed - used - refused, therefore it has emerged a philosophy called green economy, which is the combination of economic activities but without damaging the environment. It is here that the circular economy model emerges as a system that seeks the manufacture of more resistant products or the collection of raw materials through recycling for its reutilization, which represents a way of sustainable development that maintains the social responsibility from companie
Knowledge and preferences of substitution treatment of patients with chronic kidney disease
Several modalities of renal replacement therapy (RRT) are available for the treatment of end-stage renal disease (ESRD). Patients are likely to face complex medical decisions regarding the type of medical therapy they wish to pursue. A prospective, observational, descriptive and cross-sectional survey case series study was carried out in patients with grade 3-5 chronic kidney disease at the General Hospital ‘Dr. Miguel Silva’ without starting renal replacement therapy. We used descriptive statistics to evaluate the frequency of the categorical variables and measures of central tendency and dispersion for the quantitative variables. The total number of patients included was 20, with a mean age of 54.40±15.93 years and an age range between 24 and 78 years; 55% of the patients evaluated obtained a ‘good’ level of knowledge regarding the types of RRT (HD, PD and renal transplantation). All patients received pre-dialysis information before starting the survey. PD was the preferred RRT modality (45%), followed by kidney transplantation (35%) and finally HD (20%). The patient's level of knowledge regarding his chronic kidney disease allows him to make an informed decision about the choice of the ideal treatment. The most preferred renal replacement therapy for previously educated chronic kidney disease patients is peritoneal dialysis. The distance from the hemodialysis center to your home and work activity are important factors in choosing the type of RRT
Gold-Catalyzed Reaction of propargyl Esters and alkynylsilanes: Synthesis of vinylallene derivatives thorugh a Twofold 1,2-Rearrangement
The reaction of propargyl esters with alkynylsilanes under gold catalysis provides vinylallene derivatives through consecutive [1,2]-acyloxy/[1,2]-silyl rearrangements. Good yields, full atom-economy, broad substrate scope, easy scale-up and low catalyst loadings are salient features of this novel transformation. Density Functional Theory (DFT) calculations suggest a reaction mechanism involving initial [1,2]-acyloxy rearrangement to generate a gold vinylcarbene intermediate which upon regioselective attack of the alkynylsilane affords a vinyl cation which undergoes a type II-dyotropic rearrangement involving the silyl group and the metal fragment. Preliminary results on the enantioselective version of this transformation are also disclose
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