143 research outputs found
Body weight and the medial longitudinal foot arch : high-arched foot, a hidden problem?
This study had two objectives. First, to determine the prevalence of hollow (high-arched) and flat foot among primary school children in Cracow (Poland). Second, to evaluate the relationship between the type of medial longitudinal arch (MLA; determined by the Clarke’s angle) and degree of fatness. The prevalence of underweight, overweight, and obesity was determined by means of IOTF cut-offs with respect to age and gender. A sample of 1,115 children (564 boys and 551 girls) aged between 3 and 13 years was analyzed. In all age groups, regardless of gender, high-arched foot was diagnosed in the majority of children. A distinct increase in the number of children with high-arched foot was observed between 7- and 8-year olds. Regardless of the gender, high-arched foot was more common among underweight children. In the group of obese children, the biggest differences were attributed to gender. High-arched foot was the most frequently observed among boys. In all gender and obesity level groups, the flat foot was more common among boys than among girls. Conclusions: High-arched foot is the most common foot defect among children 3–13 years old regardless of gender. Flat foot is least frequently observed in children 3–13 years old. A statistic correlation between MLA and adiposity is observed. Stronger correlation is observed among girls
The Absolute Magnitude of RRc Variables From Statistical Parallax
We present the first definitive measurement of the absolute magnitude of RR
Lyrae c-type variable stars (RRc) determined purely from statistical parallax.
We use a sample of 247 RRc selected from the All Sky Automated Survey (ASAS)
for which high-quality light curves, photometry and proper motions are
available. We obtain high-resolution echelle spectra for these objects to
determine radial velocities and abundances as part of the Carnegie RR Lyrae
Survey (CARRS). We find that M_(V,RRc) = 0.52 +/- 0.11 at a mean metallicity of
[Fe/H] = -1.59. This is to be compared with previous estimates for RRab stars
(M_(V,RRab) = 0.75 +/- 0.13 and the only direct measurement of an RRc absolute
magnitude (RZ Cephei, M_(V, RRc) = 0.27 +/- 0.17). We find the bulk velocity of
the halo to be (W_pi, W_theta, W_z) = (10.9,34.9,7.2) km/s in the radial,
rotational and vertical directions with dispersions (sigma_(W_pi),
sigma_(W_theta), sigma_(W_z)) = (154.7, 103.6, 93.8) km/s. For the disk, we
find (W_pi, W_theta, W_z) = (8.5, 213.2, -22.1) km/s with dispersions
(sigma_(W_pi), sigma_(W_theta), sigma_(W_z)) = (63.5, 49.6, 51.3) km/s.
Finally, we suggest that UCAC2 proper motion errors may be overestimated by
about 25%Comment: Submitted to ApJ. 11 pages including 6 figure
Ethics of cadaveric organ procurement and allocation (II).
Transplant Proc. 2003 May;35(3):1219-20.
Ethics of cadaveric organ procurement and allocation (II).
Michałowicz B, Rev K Szczygieł, Safjan M, Rzepliński A, Land W, Norton de Matos A, Sister B Chyrowicz, Rev W Bołoz, Yussim A, Wichrowski M.
PMID: 12947911 [PubMed - indexed for MEDLINE
Discovery and Observations of ASASSN-13db, an EX Lupi-Type Accretion Event on a Low-Mass T Tauri Star
We discuss ASASSN-13db, an EX Lupi-type ("EXor") accretion event on the young
stellar object (YSO) SDSS J051011.01032826.2 (hereafter SDSSJ0510)
discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN). Using
archival photometric data of SDSSJ0510 we construct a pre-outburst spectral
energy distribution (SED) and find that it is consistent with a low-mass class
II YSO near the Orion star forming region ( pc). We present
follow-up photometric and spectroscopic observations of the source after the
5.4 magnitude outburst that began in September 2013 and ended
in early 2014. These data indicate an increase in temperature and luminosity
consistent with an accretion rate of yr,
three or more orders of magnitude greater than in quiescence. Spectroscopic
observations show a forest of narrow emission lines dominated by neutral
metallic lines from Fe I and some low-ionization lines. The properties of
ASASSN-13db are similar to those of the EXor prototype EX Lupi during its
strongest observed outburst in late 2008.Comment: 14 pages, 4 figures, 1 table. Updated May 2014 to reflect changes in
the final version published in ApJL. Photometric data presented in this
submission are included as ancillary files. For a brief video explaining this
paper, see http://youtu.be/yRCCrNJnvt
Discovery of the 2010 Eruption and the Pre-Eruption Light Curve for Recurrent Nova U Scorpii
We report the discovery by B. G. Harris and S. Dvorak on JD 2455224.9385
(2010 Jan 28.4385 UT) of the predicted eruption of the recurrent nova U Scorpii
(U Sco). We also report on 815 magnitudes (and 16 useful limits) on the
pre-eruption light curve in the UBVRI and Sloan r' and i' bands from 2000.4 up
to 9 hours before the peak of the January 2010 eruption. We found no
significant long-term variations, though we did find frequent fast variations
(flickering) with amplitudes up to 0.4 mag. We show that U Sco did not have any
rises or dips with amplitude greater than 0.2 mag on timescales from one day to
one year before the eruption. We find that the peak of this eruption occurred
at JD 2455224.69+-0.07 and the start of the rise was at JD 2455224.32+-0.12.
From our analysis of the average B-band flux between eruptions, we find that
the total mass accreted between eruptions is consistent with being a constant,
in agreement with a strong prediction of nova trigger theory. The date of the
next eruption can be anticipated with an accuracy of +-5 months by following
the average B-band magnitudes for the next ~10 years, although at this time we
can only predict that the next eruption will be in the year 2020+-2.Comment: Astronomical Journal submitted, 36 pages, 3 figures, full table
Variability of Luminous Stars in the Large Magellanic Cloud Using 10 Years of ASAS Data
Motivated by the detection of a recent outburst of the massive luminous blue
variable LMC-R71, which reached an absolute magnitude M_V = -9.3 mag, we
undertook a systematic study of the optical variability of 1268 massive stars
in the Large Magellanic Cloud, using a recent catalog by Bonanos et al. (2009)
as the input. The ASAS All Star Catalog (Pojmanski 2002) provided well-sampled
light curves of these bright stars spanning 10 years. Combining the two
catalogs resulted in 599 matches, on which we performed a variability search.
We identified 117 variable stars, 38 of which were not known before, despite
their brightness and large amplitude of variation. We found 13 periodic stars
that we classify as eclipsing binary (EB) stars, eight of which are newly
discovered bright, massive eclipsing binaries composed of OB type stars. The
remaining 104 variables are either semi- or non-periodic, the majority (85)
being red supergiants. Most (26) of the newly discovered variables in this
category are also red supergiants with only three B and four O stars.Comment: 23 pages, 10 figures and 3 tables; published in A
Orbital and physical parameters of eclipsing binaries from the ASAS catalogue - IV. A 0.61 + 0.45 M_sun binary in a multiple system
We present the orbital and physical parameters of a newly discovered low-mass
detached eclipsing binary from the All-Sky Automated Survey (ASAS) database:
ASAS J011328-3821.1 A - a member of a visual binary system with the secondary
component separated by about 1.4 seconds of arc. The radial velocities were
calculated from the high-resolution spectra obtained with the 1.9-m
Radcliffe/GIRAFFE, 3.9-m AAT/UCLES and 3.0-m Shane/HamSpec
telescopes/spectrographs on the basis of the TODCOR technique and positions of
H_alpha emission lines. For the analysis we used V and I band photometry
obtained with the 1.0-m Elizabeth and robotic 0.41-m PROMPT telescopes,
supplemented with the publicly available ASAS light curve of the system.
We found that ASAS J011328-3821.1 A is composed of two late-type dwarfs
having masses of M_1 = 0.612 +/- 0.030 M_sun, M_2 = 0.445 +/- 0.019 M_sun and
radii of R_1 = 0.596 +/- 0.020 R_sun, R_2 = 0.445 +/- 0.024 R_sun, both show a
substantial level of activity, which manifests in strong H_alpha and H_beta
emission and the presence of cool spots. The influence of the third light on
the eclipsing pair properties was also evaluated and the photometric properties
of the component B were derived. Comparison with several popular stellar
evolution models shows that the system is on its main sequence evolution stage
and probably is more metal rich than the Sun. We also found several clues which
suggest that the component B itself is a binary composed of two nearly
identical ~0.5 M_sun stars.Comment: 12 pages, 7 figures, 7 tables, to appear in MNRA
Crossing the Gould Belt in the Orion vicinity
We present a study of the large-scale spatial distribution of 6482 RASS X-ray
sources in approximately 5000 deg^2 in the direction of Orion. We examine the
astrophysical properties of a sub-sample of ~100 optical counterparts, using
optical spectroscopy. This sub-sample is used to investigate the space density
of the RASS young star candidates by comparing X-ray number counts with
Galactic model predictions. We characterize the observed sub-sample in terms of
spectral type, lithium content, radial and rotational velocities, as well as
iron abundance. A population synthesis model is then applied to analyze the
stellar content of the RASS in the studied area. We find that stars associated
with the Orion star-forming region do show a high lithium content. A population
of late-type stars with lithium equivalent widths larger than Pleiades stars of
the same spectral type (hence younger than ~70-100 Myr) is found widely spread
over the studied area. Two new young stellar aggregates, namely "X-ray Clump
0534+22" (age~2-10 Myr) and "X-ray Clump 0430-08" (age~2-20 Myr), are also
identified. The spectroscopic follow-up and comparison with Galactic model
predictions reveal that the X-ray selected stellar population in the direction
of Orion is characterized by three distinct components, namely the clustered,
the young dispersed, and the widespread field populations. The clustered
population is mainly associated with regions of recent or ongoing star
formation and correlates spatially with molecular clouds. The dispersed young
population follows a broad lane apparently coinciding spatially with the Gould
Belt, while the widespread population consists primarily of active field stars
older than 100 Myr. We expect the "bi-dimensional" picture emerging from this
study to grow in depth as soon as the distance and the kinematics of the
studied sources will become available from the future Gaia mission.Comment: 17 pages, 13 figures, 4 tables. Accepted for publication in Astronomy
and Astrophysics. Abstract shortene
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