186 research outputs found
Physiological comparison between competitive and beginner high intensity functional training athletes
Introduction: Among high intensity trainings, high intensity functional training (HIFT) represent one of the most recent developments. The aim of the present study was to investigate the differences between a group of competitive (CMP) HIFT athletes and a group of age- and gender-matched beginner (BGN) HIFT athletes, to clarify the physiological characteristics of each group and the reasons for differences. Methods: 10 BGN (32.5 ± 6.2 years) and 10 CMP (29.0 ± 5.4 years) athletes, were included in the study and were evaluated for anthropometry, VO2peak, lactate threshold, isometric and isokinetic leg maximal power and strength, handgrip and maximal anaerobic power. Results: Compared to BGN athletes, CMP reached higher levels of VO2peak (56.1 ± 2.89 ml·kg-1·min-1 CMP vs. 46.5 ± 6.86 ml·kg-1·min-1 BGN; p .006), while anaerobic capacity did not show significant differences (101.8 ± 9.33 kJ CMP vs. 87.0 ± 28.37 kJ BGN; p = .1). Conclusions: CMP athletes showed greater physiological adaptations in aerobic fitness and strength than BGN. Differences may be attributed to the technical skills acquired by CMP and not only to the physiological adaptations induced by the specific training. The lack of differences in anaerobic capacity is likely due to an early and fast improvement in BGN, compared to other parameters
Physiological profile of high intensity functional training athletes
Introduction: High intensity functional trainings (HIFT) are among the most common and popular training modalities. The aim of the present study was to examine the physiological characteristics of a group of HIFT competitive athletes both in a laboratory and field setting. Methods: Twenty HIFT athletes, 10 men (29 ± 5.3 years) and 10 women (30 ± 3.2 years), were evaluated in the laboratory for anthropometric characteristics, VO2peak, lactate threshold, maximal anaerobic power, maximal voluntary isometric and isokinetic strength, and muscle power during a countermovement jump. Athletes were also monitored in the field by measuring VO2 and lactate during a training session. Results: HIFT competitive athletes reached high levels in VO2peak (52.9 ± 5.67 ml·kg-1·min-1 in men; 52.4 ± 6.17 ml·kg-1·min-1 in women), VO2 at lactate threshold (79.7% of VO2peak in men; 74.5% of VO2peak in women), maximal anaerobic power (7.6 ± 1.32 W·kg-1 in men; 5.0 ± 1.13 W·kg-1 in women; p < .05), maximal voluntary knee extension isometric strength (11.7 ± 1.43 N·kg-1 in men; 9.5 ± 2.25 N·kg-1 in women; p < .05) and isokinetic strength (281.4 ± 31.56 N·kg-1 in men; 243.1 ± 44.13 N·kg-1 in women; p < .05), and muscle power during a countermovement jump (54 ± 5.9 W·kg-1 in men; 40 ± 4.8 W·kg-1 in women; p < .05). VO2peak during the on-field training session (50.6 ± 3.82 ml·kg-1·min-1 in men; 51.9 ± 5.76 ml·kg-1·min-1 in women) and lactate production (10.4 ± 0.69 mmol·l-1 in men; 9.7 ± 0.96 mmol·l-1 in women) revealed the high intensity nature of HIFT. Conclusions: Overall, HIFT athletes show exceptional performances in physiological components that are key to many different sports. The lack of specialization in exclusively one domain of physical fitness reveals the comprehensive nature of this training methodology
Physiological comparison between competitive and beginner high intensity functional training athletes
Introduction: Among high intensity trainings, high intensity functional training (HIFT) represent one of the most recent developments. The aim of the present study was to investigate the differences between a group of competitive (CMP) HIFT athletes and a group of age- and gender-matched beginner (BGN) HIFT athletes, to clarify the physiological characteristics of each group and the reasons for differences. Methods: 10 BGN (32.5 ± 6.2 years) and 10 CMP (29.0 ± 5.4 years) athletes, were included in the study and were evaluated for anthropometry, VO2peak, lactate threshold, isometric and isokinetic leg maximal power and strength, handgrip and maximal anaerobic power. Results: Compared to BGN athletes, CMP reached higher levels of VO2peak (56.1 ± 2.89 ml·kg-1·min-1 CMP vs. 46.5 ± 6.86 ml·kg-1·min-1 BGN; p .006), while anaerobic capacity did not show significant differences (101.8 ± 9.33 kJ CMP vs. 87.0 ± 28.37 kJ BGN; p = .1). Conclusions: CMP athletes showed greater physiological adaptations in aerobic fitness and strength than BGN. Differences may be attributed to the technical skills acquired by CMP and not only to the physiological adaptations induced by the specific training. The lack of differences in anaerobic capacity is likely due to an early and fast improvement in BGN, compared to other parameters
Melusin is a new muscle-specific interactor for beta(1) integrin cytoplasmic domain.
Here we describe the isolation and partial characterization of a new muscle-specific protein (Melusin) which interacts with the integrin cytoplasmic domain. The cDNA encoding Melusin was isolated in a two-hybrid screening of a rat neonatal heart library using beta(1)A and beta(1)D integrin cytoplasmic regions as baits. Melusin is a cysteine-rich cytoplasmic protein of 38 kDa, with a stretch of acidic amino acid residues at the extreme carboxyl-terminal end. In addition, putative binding sites for SH3 and SH2 domains are present in the amino-terminal half of the molecule. Chromosomic analysis showed that melusin gene maps at Xq12.1/13 in man and in the synthenic region X band D in mouse. Melusin is expressed in skeletal and cardiac muscles but not in smooth muscles or other tissues. Immunofluorescence analysis showed that Melusin is present in a costamere-like pattern consisting of two rows flanking alpha-actinin at Z line. Its expression is up-regulated during in vitro differentiation of the C2C12 murine myogenic cell line, and it is regulated during in vivo skeletal muscle development. A fragment corresponding to the tail region of Melusin interacted strongly and specifically with beta(1) integrin cytoplasmic domain in a two-hybrid test, but the full-length protein did not. Because the tail region of Melusin contains an acidic amino acid stretch resembling high capacity and low affinity calcium binding domains, we tested the possibility that Ca(2+) regulates Melusin-integrin association. In vitro binding experiments demonstrated that interaction of full-length Melusin with detergent-solubilized integrin heterodimers occurred only in absence of cations, suggesting that it can be regulated by intracellular signals affecting Ca(2+) concentration
All-sky search of NAUTILUS data
A search for periodic gravitational-wave signals from isolated neutron stars
in the NAUTILUS detector data is presented. We have analyzed half a year of
data over the frequency band Hz/s and over the entire sky. We have divided the
data into 2 day stretches and we have analyzed each stretch coherently using
matched filtering. We have imposed a low threshold for the optimal detection
statistic to obtain a set of candidates that are further examined for
coincidences among various data stretches. For some candidates we have also
investigated the change of the signal-to-noise ratio when we increase the
observation time from two to four days. Our analysis has not revealed any
gravitational-wave signals. Therefore we have imposed upper limits on the
dimensionless gravitational-wave amplitude over the parameter space that we
have searched. Depending on frequency, our upper limit ranges from to . We have attempted a statistical
verification of the hypotheses leading to our conclusions. We estimate that our
upper limit is accurate to within 18%.Comment: LaTeX, 12 page
IGEC2: A 17-month search for gravitational wave bursts in 2005-2007
We present here the results of a 515 days long run of the IGEC2 observatory,
consisting of the four resonant mass detectors ALLEGRO, AURIGA, EXPLORER and
NAUTILUS. The reported results are related to the fourfold observation time
from Nov. 6 2005 until Apr. 14 2007, when Allegro ceased its operation. This
period overlapped with the first long term observations performed by the LIGO
interferometric detectors. The IGEC observations aim at the identification of
gravitational wave candidates with high confidence, keeping the false alarm
rate at the level of 1 per century, and high duty cycle, namely 57% with all
four sites and 94% with at least three sites in simultaneous observation. The
network data analysis is based on time coincidence searches over at least three
detectors: the four 3-fold searches and the 4-fold one are combined in a
logical OR. We exchanged data with the usual blind procedure, by applying a
unique confidential time offset to the events in each set of data. The
accidental background was investigated by performing sets of 10^8 coincidence
analyses per each detector configuration on off-source data, obtained by
shifting the time series of each detector. The thresholds of the five searches
were tuned so as to control the overall false alarm rate to 1/century. When the
confidential time shifts was disclosed, no gravitational wave candidate was
found in the on-source data. As an additional output of this search, we make
available to other observatories the list of triple coincidence found below
search thresholds, corresponding to a false alarm rate of 1/month.Comment: 10 pages, 8 figures Accepted for publication on Phys. Rev.
Results of the IGEC-2 search for gravitational wave bursts during 2005
The network of resonant bar detectors of gravitational waves resumed
coordinated observations within the International Gravitational Event
Collaboration (IGEC-2). Four detectors are taking part in this collaboration:
ALLEGRO, AURIGA, EXPLORER and NAUTILUS. We present here the results of the
search for gravitational wave bursts over 6 months during 2005, when IGEC-2 was
the only gravitational wave observatory in operation. The network data analysis
implemented is based on a time coincidence search among AURIGA, EXPLORER and
NAUTILUS, keeping the data from ALLEGRO for follow-up studies. With respect to
the previous IGEC 1997-2000 observations, the amplitude sensitivity of the
detectors to bursts improved by a factor about 3 and the sensitivity bandwidths
are wider, so that the data analysis was tuned considering a larger class of
detectable waveforms. Thanks to the higher duty cycles of the single detectors,
we decided to focus the analysis on three-fold observation, so to ensure the
identification of any single candidate of gravitational waves (gw) with high
statistical confidence. The achieved false detection rate is as low as 1 per
century. No candidates were found.Comment: 10 pages, to be submitted to Phys. Rev.
Virgo calibration and reconstruction of the gravitational wave strain during VSR1
Virgo is a kilometer-length interferometer for gravitational waves detection
located near Pisa. Its first science run, VSR1, occured from May to October
2007. The aims of the calibration are to measure the detector sensitivity and
to reconstruct the time series of the gravitational wave strain h(t). The
absolute length calibration is based on an original non-linear reconstruction
of the differential arm length variations in free swinging Michelson
configurations. It uses the laser wavelength as length standard. This method is
used to calibrate the frequency dependent response of the Virgo mirror
actuators and derive the detector in-loop response and sensitivity within ~5%.
The principle of the strain reconstruction is highlighted and the h(t)
systematic errors are estimated. A photon calibrator is used to check the sign
of h(t). The reconstructed h(t) during VSR1 is valid from 10 Hz up to 10 kHz
with systematic errors estimated to 6% in amplitude. The phase error is
estimated to be 70 mrad below 1.9 kHz and 6 micro-seconds above.Comment: 8 pages, 8 figures, proceedings of Amaldi 8 conference, to be
published in Journal of Physics Conference Series (JPCS). Second release:
correct typo
A Cross-correlation method to search for gravitational wave bursts with AURIGA and Virgo
We present a method to search for transient GWs using a network of detectors
with different spectral and directional sensitivities: the interferometer Virgo
and the bar detector AURIGA. The data analysis method is based on the
measurements of the correlated energy in the network by means of a weighted
cross-correlation. To limit the computational load, this coherent analysis step
is performed around time-frequency coincident triggers selected by an excess
power event trigger generator tuned at low thresholds. The final selection of
GW candidates is performed by a combined cut on the correlated energy and on
the significance as measured by the event trigger generator. The method has
been tested on one day of data of AURIGA and Virgo during September 2005. The
outcomes are compared to the results of a stand-alone time-frequency
coincidence search. We discuss the advantages and the limits of this approach,
in view of a possible future joint search between AURIGA and one
interferometric detector.Comment: 11 pages, 6 figures, submitted to CQG special issue for Amaldi 7
Proceeding
Calibration and sensitivity of the Virgo detector during its second science run
The Virgo detector is a kilometer-length interferometer for gravitational
wave detection located near Pisa (Italy). During its second science run (VSR2)
in 2009, six months of data were accumulated with a sensitivity close to its
design. In this paper, the methods used to determine the parameters for
sensitivity estimation and gravitational wave reconstruction are described. The
main quantities to be calibrated are the frequency response of the mirror
actuation and the sensing of the output power. Focus is also put on their
absolute timing. The monitoring of the calibration data as well as the
parameter estimation with independent techniques are discussed to provide an
estimation of the calibration uncertainties. Finally, the estimation of the
Virgo sensitivity in the frequency-domain is described and typical
sensitivities measured during VSR2 are shown.Comment: 30 pages, 23 figures, 1 table. Published in Classical and Quantum
Gravity (CQG), Corrigendum include
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