1,823 research outputs found
Electromyographic analysis of the up and down step: comparative dry and water
Electromyographic analysis of the up and down step: comparative dry and water
The aim of the present study was to compare the muscular activity with surface
electromyography of the lower limb and the trunk muscles during up and down step in dry land and into the water environments comparing young and elderly population.
Methods: An analytical cross-sectional inferential study was carried out in order to compare the muscle activation between dry land and aquatic environments. Sixteen non-pathological subjects participated in the present study. Eight muscles were recorded in a telematic and simultaneous manner by immersing the device in water (if necessary) with a sampling frequency of 1000 Hz. The functional task up and down step was performed at a rhythm of 5 repetitions at 25 BPM (measured using a metronome), the height of the step was 18 cm. The task was performed both in dry and in water with the same height of the step and the same rhythm in both environments. The waterline was in one meter, water
temperature was 30°C. Results: In older people, significant differences between dry and water during up step in the distribution of muscle activation were found. Young groups shown significant differences in all muscles analyzed with the exception of the spinal erector. However, for the down step in the group of young people (table 3), significant differences were observerd for all muscles except for the musculature of the trunk and rectus femoris In the aquatic environment, elderly group showed significant differences for the muscle activation compared to the young for all muscles of the thigh and leg except for the tibialis anterior during up step task. However, in the down step in the aquatic environment, only significant differences were obtained in favor of the elderly group in the musculature of the thigh.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
Supervised classification for a family of Gaussian functional models
In the framework of supervised classification (discrimination) for functional
data, it is shown that the optimal classification rule can be explicitly
obtained for a class of Gaussian processes with "triangular" covariance
functions. This explicit knowledge has two practical consequences. First, the
consistency of the well-known nearest neighbors classifier (which is not
guaranteed in the problems with functional data) is established for the
indicated class of processes. Second, and more important, parametric and
nonparametric plug-in classifiers can be obtained by estimating the unknown
elements in the optimal rule. The performance of these new plug-in classifiers
is checked, with positive results, through a simulation study and a real data
example.Comment: 30 pages, 6 figures, 2 table
Onda corta vs. radio online. Radio Exterior de España en la era digital
Fernández Cuesta, Antonio (2013). Onda corta vs. radio online. Radio Exterior
de España en la era digital. En: adComunica. Revista CientÃfica de Estrategias,
Tendencias e Innovación en Comunicación, nº5. Castellón: Asociación para
el Desarrollo de la Comunicación adComunica, Universidad Complutense de
Madrid y Universitat Jaume I, 251-254. DOI: http://dx.doi.org/10.6035/2174-
0992.2013.5.1
Constraints on deviations from CDM within Horndeski gravity
Recent anomalies found in cosmological datasets such as the low multipoles of
the Cosmic Microwave Background or the low redshift amplitude and growth of
clustering measured by e.g., abundance of galaxy clusters and redshift space
distortions in galaxy surveys, have motivated explorations of models beyond
standard CDM. Of particular interest are models where general
relativity (GR) is modified on large cosmological scales. Here we consider
deviations from CDM+GR within the context of Horndeski gravity, which
is the most general theory of gravity with second derivatives in the equations
of motion. We adopt a parametrization in which the four additional Horndeski
functions of time are proportional to the cosmological density of
dark energy . Constraints on this extended parameter space
using a suite of state-of-the art cosmological observations are presented for
the first time. Although the theory is able to accommodate the low multipoles
of the Cosmic Microwave Background and the low amplitude of fluctuations from
redshift space distortions, we find no significant tension with CDM+GR
when performing a global fit to recent cosmological data and thus there is no
evidence against CDM+GR from an analysis of the value of the Bayesian
evidence ratio of the modified gravity models with respect to CDM,
despite introducing extra parameters. The posterior distribution of these extra
parameters that we derive return strong constraints on any possible deviations
from CDM+GR in the context of Horndeski gravity. We illustrate how our
results can be applied to a more general frameworks of modified gravity models.Comment: 22 pages; 4 figures; 9 tables. The constraints have been revised to
match the precision required according to the recently released hi_class
pape
La ciència-ficció com a element d'inspiració de la tecnologia i motivació de l'alumnat
Analitzar la percepció que tenen els alumnes de la ciència ficció i investigar quines són les formes en que es relacionen amb ella. Aquesta anà lisi ha d'orientar en l'ús de material didà ctic per buscar les formes més efectives i assimilables per la major part de l'alumnat. Promoure la curiositat per la ciència ficció com element d'inspiració per a nous reptes i creativitat, tot seguint l'esperit de la 3ª llei d'Arthur C. Clarke: "qualsevol tecnologia suficientment avançada és indistingible de la mà gia". Identificar l'impacte de la tecnologia sobre la forma de vida de les persones, contextualitzant el seu estat en el darrer segle i les tendències més immediates
MTUG: an Instrumented Timed Up and Go Extended Test.
Background
The aim of this study was to, using the inertial sensor found in the iPhone4®, locate in the ten meter Extended Timed Get Up and Go test the series of kinematic variables deriving from accelerometry and from angular velocity and displacement which show the greatest level of precision in order to discriminate between two groups of elderly persons (frail and physically active) compared to the traditionally used variable, namely time.
Methods
This study used the transversal analytical approach in an attempt to locate the series of kinematic variables which showed the highest degree of precision in order to discriminate between two groups. Firstly, the differences between the two groups (frail elderly persons and healthy elderly persons) were analyzed using variance analysis. The statistical significance level was established at p<0.05. Secondly, Receiver Operating Characteristic (ROC) curves were drawn up in order to evaluate the level of precision in the predictive capability of the kinematic variables compared to the traditionally used variable, namely time.
Results
In phases Si-St and T-St-Si, the results indicate that the variables for acceleration showed greater sensitivity in terms of discriminating between the population groups in the study than the angular velocity and displacement data; specifically, they were the minimum acceleration variables in motion axes x, z and y. In sub-phases GG and GC, accelerations in the x axis showed greater discrimination sensitivity between the frail and the controls. For the turning phase, the minimum acceleration variables which obtained area values below the curve greater than for time were the accelerations in the z and y axes.
Conclusions
The readings deriving from acceleration and angular velocity and displacement during the ETGUG test present a higher degree of precision in discrimination capability between a group of frail and a group of physically active elderly persons, in a more sensitive manner than the variable traditionally used in this test, namely time.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tec
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