376 research outputs found
A Safety Net In The E-Marketplace: The Safe Harbor Principles Offer Comprehensive Privacy Protection Without Stopping Data Flow
In May of 2000, the FTC, under Chairman Robert Pitofsky, concluded that industry self-regulation was not effective in protecting consumer privacy and in a report to Congress the FTC expressed the view that legislation [was] necessary to ensure further implementation of consumer data protection devices
THE EFFECT OF A GREEK TRADITIONAL DANCE PROGRAM ON THE MOTOR COMPETENCE OF CHILDREN WITH AUTISM SPECTRUM DISORDER
It is usual for individuals with autism spectrum disorder (ASD) to demonstrate deficits in motor behavior. Participation in movement programs has been suggested to elicit improvements in their motor competence (MC) level. The aim of the present study was to examine the effect of a Greek traditional dance (GTD) program on the MC of 6-14-year-old children with ASD. The study design included eight participants (two girls, six boys), who were randomly allocated into two equal-sized groups, group A (its members participated only in the regular Physical Education lessons provided by their school) and group B (its members additionally followed an 8-week GTD program of two 40-min sessions per week). Children’s MC was assessed prior and immediately after the completion of the GTD program by the Bruininks- Oseretsky Test of Motor Proficiency (BOT-2 SF). Due to study’s small sample size and participants’ heterogenous ASD characteristics, the results will be interpreted as outcomes of multiple single case studies. Overall, it was observed that the MC of all participants was considerably poor; however, members of group B made greater improvements in both the total BOT-2 point score and most item raw scores compared to those of group A, with balance and body coordination skills presenting the greater improvements. Even though the results of this study stress the positive effect of GTD on the MC of children with ASD, future studies employing wider sample sizes and/or implementing longer programs are required to further confirm its merit.
Article visualizations
Towards a Functional Approach to the Assessment of Daily Life Physical Activity in Children: Are the PAQ-C and Fitbit Flex-2 Technically Adequate?
Considering the need for functional physical activity (PA) measures in PA settings, this study sought to determine the technical adequacy of the Physical Activity Questionnaire for Older Children (PAQ-C) and the Fitbit Flex-2, two instruments with promising features for wide use, using the Actigraph GT3X+ accelerometer as the criterion reference. A total of 218 Greek children (94 boys, 124 girls; mean age = 10.99 ± 1.52 years) volunteered to join in. Participants wore the PA trackers for seven days and completed the PAQ-C. Moreover, a sub-group (n = 60) recompleted the PAQ-C after a week. Results revealed acceptable internal consistency and excellent test–retest reliability for the PAQ-C. Regarding concurrent validity, weak to moderate correlations with PA parameters recorded by the GT3X+ were revealed for the total PAQ-C and were excellent for the Flex-2, while a Bland–Altman plot indicated good agreement. Finally, in alignment with relevant literature, significant gender, but no age, differences were found in participants’ PA records in all the tools applied. The above results support the use of the PAQ-C and the Fitbit Flex-2 in children. Considering that they shed light into different parameters of children’s habitual PA, their combined utilisation, providing comprehensive information, is strongly recommended.This research was supported by the European Union’s HORIZON 2020 Programme (2014–2020) under ID n 777082,
and by the Brazilian Ministry of Science, Technology and Innovation through Rede Nacional de Ensino e Pesquisa (RNP) under Ocariot
Searching for tidal tails - investigating galaxy harassment
Galaxy harassment has been proposed as a physical process that
morphologically transforms low surface density disc galaxies into dwarf
elliptical galaxies in clusters. It has been used to link the observed very
different morphology of distant cluster galaxies (relatively more blue galaxies
with 'disturbed' morphologies) with the relatively large numbers of dwarf
elliptical galaxies found in nearby clusters. One prediction of the harassment
model is that the remnant galaxies should lie on low surface brightness tidal
streams or arcs. We demonstrate in this paper that we have an analysis method
that is sensitive to the detection of arcs down to a surface brightness of 29 B
mag/arcsec^2 and then use this method to search for arcs around 46 Virgo
cluster dwarf elliptical galaxies. We find no evidence for tidal streams or
arcs and consequently no evidence for galaxy harassment as a viable explanation
for the relatively large numbers of dwarf galaxies found in the Virgo cluster.Comment: Accepted for publication in MNRA
Faint dwarf spheroidals in the Fornax Cluster: A flat luminosity function
We have discovered about 70 very faint dwarf galaxies in the Fornax Cluster.
These dSphs candidates follow the same magnitude-surface brightness relation as
their counterparts in the Local Group, and even extend it to fainter limits.
The faintest dSph candidate in our sample has an absolute magnitude of M_V =
-8.8 mag and a central surface brightness of mu_V = 27 mag/arcsec^2. There
exists a tight color-magnitude relation for the early-type galaxies in Fornax
that extends from the giant to the dwarf regime. The faint-end slope of the
luminosity function of the early-type dwarfs is flat (alpha = -1.1+/-0.1),
contrary to the results obtained by Kambas et al. (2000).Comment: 4 pages, 3 figures, accepted for publication in Astronomy &
Astrophysics (Letters
Potential of the Surface Brightness Fluctuations method to measure distances to dwarf elliptical galaxies in nearby clusters
The potential of the Surface Brightness Fluctuations (SBF) method to
determine the membership of dwarf elliptical galaxies (dEs) in nearby galaxy
clusters is investigated. Extensive simulations for SBF measurements on dEs in
the I-band for various combinations of distance modulus, seeing and integration
time are presented, based on average VLT FORS1 and FORS2 zero points. These
show that for distances up to 20 Mpc (Fornax or Virgo cluster distance),
reliable membership determination of dEs can be obtained down to very faint
magnitudes -10<M_V<-12 mag (25 mag / arcsec^2) within integration times of the
order of 1 hour and with good seeing. Comparing the limiting magnitudes of the
method for the different simulated observing conditions we derive some simple
rules to calculate integration time and seeing needed to reach a determined
limiting magnitude at a given distance modulus for observing conditions
different to the ones adopted in the simulations. Our simulations show a small
offset of the order of 0.15 mag towards measuring too faint SBF. It is shown
that this is due to loss of fluctuation signal when recovering pixel-to-pixel
fluctuations from a seeing convolved image. To check whether our simulations
represent well the behaviour of real data, SBF measurements for a real and
simulated sample of bright Centaurus Cluster dEs are presented. They show that
our simulations are in good agreement with the achievable S/N of SBF
measurements on real galaxies.Comment: 12 pages, 8 figures, accepted by A&A, replaced by version with
non-abridged bottom page limi
Multicolor Photometry Study of the Galaxy Cluster A2589: Dynamics, Luminosity Function and Star Formation History
In this paper we present a multicolor photometry for A2589 () with
15 intermediate bands in the Beijing-Arizona-Taiwan-Connecticut (BATC) system
which covers an optical wavelength range from 3000 \AA\ to 10000 \AA. The
spectral energy distributions (SEDs) for more than 5000 sources are achieved
down to {\it V} 20 mag in about 1 deg field. A2589 has been also
covered by the Sloan Digital Sky Survey (SDSS) in photometric mode only. A
cross-identification of the BATC-detected galaxies with the SDSS photometric
catalog achieves 1199 galaxies brighter than mag, among which 68
member galaxies with known spectroscopic redshifts are found. After combining
the SDSS five-band photometric data and the BATC SEDs, the technique of
photometric redshift is applied to these galaxies for selecting faint member
galaxies. The color-magnitude relation is taken as a further restriction of
early-type cluster galaxies. As a result, 106 galaxies are newly selected as
member galaxies. Spatial distribution of member galaxies shows a north-south
elongation which agrees with the X-ray brightness profile and the orientation
of central cD galaxy, NGC 7647. No substructures are detected on the basis of
positions and radial velocities of cluster galaxies, indicating that A2589 is a
well-relaxed system. The luminosity function of A2589 exhibits a peak at mag and a dip at mag. The low-density outer regions
are the preferred habitat of faint galaxies. With the evolutionary population
synthesis model, PEGASE, the environmental effect on the star formation
properties for 68 spectroscopically confirmed member galaxies is studied. The
outlier faint galaxies tend to have longer time scales of star formation,
shorter mean stellar ages, and lower metallicities of interstellar medium,
which can be interpreted in the context of hierarchical cosmological scenario.Comment: 2011 Accepted to A
The Low Surface Brightness Extent of the Fornax Cluster
We have used a large format CCD camera to survey the nearby Fornax cluster
and its immediate environment for low luminosity low surface brightness
galaxies. Recent observations indicate that these are the most dark matter
dominated galaxies known and so they are likely to be a good tracer of the dark
matter in clusters. We have identified large numbers of these galaxies
consistent with a steep faint end slope of the luminosity function (alpha~ -2)
down to MB ~ -12. These galaxies contribute almost the same amount to the total
cluster light as the brighter galaxies and they have a spatial extent that is
some four times larger. They satisfy two of the important predictions of N-body
hierarchical simulations of structure formation using dark halos. The
luminosity (mass ?) function is steep and the mass distribution is more
extended than that defined by the brighter galaxies. We also find a large
concentration of low surface brightness galaxies around the nearby galaxy
NGC1291.Comment: 16 pages, 6 figure
- …