1,686 research outputs found
Using wearables to monitor swimmers’ propulsive force to get real-time feedback and understand its relationship to swimming velocity
Evidence on the role of propulsion compared to drag in swimming, based on experimental
settings, is still lacking. However, higher levels of propulsion seem to lead to faster swimming veloci-
ties. The aim of this study was to understand the variation in a set of kinematic and kinetic variables
between two swimming sections and their relationship to swimming velocity. The sample consisted
of 15 young adult recreational swimmers (8 males: 20.84 ± 2.03 years; 7 females: 20.13 ± 1.90 years).
Maximum swimming velocity and a set of kinematic and kinetic variables were measured during
two consecutive sections of the swimming pool. Differences between sections were measured and
the determinants of swimming velocity were analyzed. Swimming velocity, propulsive force, and the
other kinematic and kinetic variables did not change significantly (p < 0.05) between sections (only
the intra-cyclic fluctuation of swimming velocity decreased significantly, p = 0.005). The modeling
identified the propulsive force, stroke length, and active drag coefficient as the determinants of
swimming velocity. Swimming velocity was determined by the interaction of kinematic and kinetic
variables, specifically propulsive force and active drag coefficientThis research was funded by FCT—Portuguese Foundation for Science and Technology,
grant number UIDB/DTP/04045/2020info:eu-repo/semantics/publishedVersio
The effectiveness of pilates training interventions on older adults’ balance: a systematic review and meta-analysis of randomized controlled trials
Pilates training intervention programs have gained attention as a potential approach to enhancing balance in older adults, thereby reducing the risk of falls. In light of these considerations, this systematic review and meta-analysis aimed to critically evaluate the existing evidence and determine the effect of Pilates training intervention programs on older adults’ balance. Materials and Methods: The literature was searched through the PubMed, Web of Science, and Scopus databases from inception until July 2023. The primary keywords used for the literature search included “elderly” or “older adults” and “pilates training” and “balance”. Results: The systematic review through qualitative analysis showed robust evidence about the efficacy of Pilates intervention programs in improving older adults’ balance. The pooled meta-analysis of static and dynamic balance showed that eight (53%) out of a total fifteen analyzed interventions presented a significant effect of Pilates in improving the participants’ balance, without between-study heterogeneity. In addition, the meta-analysis regarding dynamic balance showed that six (67%) out of nine analyzed interventions presented a significant effect of Pilates in improving the participants’ balance, without heterogeneity between studies. Similarly, the meta-analysis regarding static balance showed that four (50%) out of eight analyzed studies presented significant effects on the older adults’ balance, where moderate between-study heterogeneity was found. Sensitivity analysis showed that three studies reduced the between-study heterogeneity (19, 17.6, and 17%), regressing from moderate to low heterogeneity, p < 0.05. Conclusions: This systematic review and meta-analysis underscores the potential of Pilates training as a valuable intervention to enhance balance in the elderly populationThis work is supported by national funding through the Portuguese Foundation for Science and Technology, I.P., under the project UIDB/04045/2020.info:eu-repo/semantics/publishedVersio
Prospective evaluation of glutamine and phospholipids levels in first degree relatives of patients with Type 1 Diabetes from a multiethnic population
A dysregulation in the metabolism of lipids may be an early marker of autoimmunity in Type 1 Diabetes (T1D). It would be of general importance to identify metabolic patterns that would predict the risk for T1D later in life. The aim of this study was to perform a prospective evaluation of glutamine and phospholipids levels in Brazilian first degree relatives (FDR) of patients with T1D in a mean interval of 5 years
Measuring CMB Polarization with BOOMERANG
BOOMERANG is a balloon-borne telescope designed for long duration (LDB)
flights around Antarctica. The second LDB Flight of BOOMERANG took place in
January 2003. The primary goal of this flight was to measure the polarization
of the CMB. The receiver uses polarization sensitive bolometers at 145 GHz.
Polarizing grids provide polarization sensitivity at 245 and 345 GHz. We
describe the BOOMERANG telescope noting changes made for 2003 LDB flight, and
discuss some of the issues involved in the measurement of polarization with
bolometers. Lastly, we report on the 2003 flight and provide an estimate of the
expected results.Comment: 12 pages, 8 figures, To be published in the proceedings of "The
Cosmic Microwave Background and its Polarization", New Astronomy Reviews,
(eds. S. Hanany and K.A. Olive). Fixed typos, and reformatted citation
Suppressing CMB Quadrupole with a Bounce from Contracting Phase to Inflation
Recent released WMAP data show a low value of quadrupole in the CMB
temperature fluctuations, which confirms the early observations by COBE. In
this paper, a scenario, in which a contracting phase is followed by an
inflationary phase, is constructed. We calculate the perturbation spectrum and
show that this scenario can provide a reasonable explanation for lower CMB
anisotropies on large angular scales.Comment: 5 pages, 3 figure
The Infrared Behaviour of the Pure Yang-Mills Green Functions
We review the infrared properties of the pure Yang-Mills correlators and
discuss recent results concerning the two classes of low-momentum solutions for
them reported in literature; i.e. decoupling and scaling solutions. We will
mainly focuss on the Landau gauge and pay special attention to the results
inferred from the analysis of the Dyson-Schwinger equations of the theory and
from "{\it quenched}" lattice QCD. The results obtained from properly
interplaying both approaches are strongly emphasized.Comment: Final version to be published in FBS (54 pgs., 11 figs., 4 tabs
Progress in analytical approaches integrating Livestock and Biodiversity to identify HNV Montados
The World Congress Silvo-Pastoral Systems 2016 aims to gather researchers from different disciplines, practitioners and policy makers at different governance levels that deal with the management and sustainability of silvo-pastoral systems. In this way the congress will create a fertile context to progress through interdisciplinarity research approaches that can help translate scientific knowledge into new adaptive management solutions, and thus bridge from science to practice. The aim is also to gather and compare knowledge from silvo-pastoral systems around the world, which share drought as a limiting factor, so that they can be discussed and evaluated
Tidal Dwarf Galaxies at Intermediate Redshifts
We present the first attempt at measuring the production rate of tidal dwarf
galaxies (TDGs) and estimating their contribution to the overall dwarf
population. Using HST/ACS deep imaging data from GOODS and GEMS surveys in
conjunction with photometric redshifts from COMBO-17 survey, we performed a
morphological analysis for a sample of merging/interacting galaxies in the
Extended Chandra Deep Field South and identified tidal dwarf candidates in the
rest-frame optical bands. We estimated a production rate about 1.4 {\times}
10^{-5} per Gyr per comoving volume for long-lived TDGs with stellar mass 3
{\times} 10^{8-9} solar mass at 0.5<z<1.1. Together with galaxy merger rates
and TDG survival rate from the literature, our results suggest that only a
marginal fraction (less than 10%) of dwarf galaxies in the local universe could
be tidally-originated. TDGs in our sample are on average bluer than their host
galaxies in the optical. Stellar population modelling of optical to
near-infrared spectral energy distributions (SEDs) for two TDGs favors a burst
component with age 400/200 Myr and stellar mass 40%/26% of the total,
indicating that a young stellar population newly formed in TDGs. This is
consistent with the episodic star formation histories found for nearby TDGs.Comment: 9 pages, 5 figures, Accepted for publication in Astrophysics & Space
Scienc
Biological response to pre-mineralized starch based scaffolds for bone tissue engineering
It is known that calcium-phosphate (Ca-P) coatings are able not only to improve the bone
bonding behaviour of polymeric materials, but at the same time play a positive role on
enhancing cell adhesion and inducing the differentiation of osteoprogenitor cells. Recently
an innovative biomimetic methodology, in which a sodium silicate gel was used as a
nucleative agent, was proposed as an alternative to the currently available biomimetic
coating methodologies. This methodology is especially adequate for coating biodegradable
porous scaffolds. In the present work we evaluated the influence of the referred to
treatment on the mechanical properties of 50/50 (wt%) blend of corn starch/ethylene-vinyl
alcohol (SEVA-C) based scaffolds. These Ca-P coated scaffolds presented a compressive
modulus of 224.6 ± 20.6 and a compressive strength of 24.2 ± 2.20. Cytotoxicity evaluation
was performed according ISO/EN 10993 part 5 guidelines and showed that the biomimetic
treatment did not have any deleterious effect on L929 cells and did not inhibit cell growth.
Direct contact assays were done by using a cell line of human osteoblast like cells (SaOS-2).
3 Ă— 105 cells were seeded per scaffold and allowed to grow for two weeks at 37 â—¦C in a
humidified atmosphere containing 5% CO2. Total protein quantification and scanning
electron microscopy (SEM) observation showed that cells were able to grow in the
pre-mineralized scaffolds. Furthermore cell viability assays (MTS test) also show that cells
remain viable after two weeks in culture. Finally, protein expression studies showed that
after two weeks osteopontin and collagen type I were being expressed by SaOS-2 cells
seeded on the pre-mineralized scaffolds. Moreover, alkaline phosphatase (ALP) activity was
higher in the supernatants collected from the pre-mineralized samples, when compared to
the control samples (non Ca-P coated). This may indicate that a faster mineralization of the
ECM produced on the pre-mineralized samples was occurring. Consequently, biomimetic
pre-mineralization of starch based scaffolds can be a useful route for applying these
materials on bone tissue engineering
Cosmological parameters from SDSS and WMAP
We measure cosmological parameters using the three-dimensional power spectrum
P(k) from over 200,000 galaxies in the Sloan Digital Sky Survey (SDSS) in
combination with WMAP and other data. Our results are consistent with a
``vanilla'' flat adiabatic Lambda-CDM model without tilt (n=1), running tilt,
tensor modes or massive neutrinos. Adding SDSS information more than halves the
WMAP-only error bars on some parameters, tightening 1 sigma constraints on the
Hubble parameter from h~0.74+0.18-0.07 to h~0.70+0.04-0.03, on the matter
density from Omega_m~0.25+/-0.10 to Omega_m~0.30+/-0.04 (1 sigma) and on
neutrino masses from <11 eV to <0.6 eV (95%). SDSS helps even more when
dropping prior assumptions about curvature, neutrinos, tensor modes and the
equation of state. Our results are in substantial agreement with the joint
analysis of WMAP and the 2dF Galaxy Redshift Survey, which is an impressive
consistency check with independent redshift survey data and analysis
techniques. In this paper, we place particular emphasis on clarifying the
physical origin of the constraints, i.e., what we do and do not know when using
different data sets and prior assumptions. For instance, dropping the
assumption that space is perfectly flat, the WMAP-only constraint on the
measured age of the Universe tightens from t0~16.3+2.3-1.8 Gyr to
t0~14.1+1.0-0.9 Gyr by adding SDSS and SN Ia data. Including tensors, running
tilt, neutrino mass and equation of state in the list of free parameters, many
constraints are still quite weak, but future cosmological measurements from
SDSS and other sources should allow these to be substantially tightened.Comment: Minor revisions to match accepted PRD version. SDSS data and ppt
figures available at http://www.hep.upenn.edu/~max/sdsspars.htm
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