57 research outputs found
Fertility knowledge and the timing of first childbearing: a cross-sectional study in Japan
Although fertility educational initiatives have increased in developed countries to prevent infertility and to broaden fertility choices, the relationship between knowledge and behaviour is still poorly understood. In order to investigate the association between fertility knowledge and timing of childbearing, we investigated male and female participants between 35 and 44 years of age who had children (n = 640) from an online survey conducted in Japan in 2013. The age at which participants actually gave birth to or fathered their first child was compared between those who were aware for at least a decade of age-related decline in female fertility (hereinafter, those with past fertility knowledge) and those without. Age at first birth was significantly younger and more narrowly distributed among women with past fertility knowledge than among those without: 28.2 ± 3.4 vs. 29.8 ± 4.6 (mean ± SD). A multivariate linear regression analysis showed that women with past fertility knowledge gave birth to their first child 2.34 [95% confidence interval (CI): 1.09–3.59] years earlier compared to those without such knowledge. No significant relation existed among men. Being informed in young adulthood about the facts of fertility might be related to starting a family at an earlier age, although further longitudinal evaluation will be necessary
Outburst of LS V+44 17 Observed by MAXI and RXTE, and Discovery of a Dip Structure in the Pulse Profile
We report on the first observation of an X-ray outburst of a Be/X-ray binary
pulsar LS V +44 17/RX J0440.9+4431, and the discovery of an absorption dip
structure in the pulse profile. An outburst of this source was discovered by
MAXI GSC in 2010 April. It was the first detection of the transient activity of
LS V +44 17 since the source was identified as a Be/X-ray binary in 1997. From
the data of the follow-up RXTE observation near the peak of the outburst, we
found a narrow dip structure in its pulse profile which was clearer in the
lower energy bands. The pulse-phase-averaged energy spectra in the 3100 keV
band can be fitted with a continuum model containing a power-law function with
an exponential cutoff and a blackbody component, which are modified at low
energy by an absorption component. A weak iron K emission line is also
detected in the spectra. From the pulse-phase-resolved spectroscopy we found
that the absorption column density at the dip phase was much higher than those
in the other phases. The dip was not seen in the subsequent RXTE observations
at lower flux levels. These results suggest that the dip in the pulse profile
originates from the eclipse of the radiation from the neutron star by the
accretion column.Comment: 18 pages, 7 figures, accepted for publication in PAS
Long-term Monitoring of the Black Hole Binary GX 339-4 in the High/Soft State during the 2010 Outburst with MAXI/GSC
We present the results of monitoring the Galactic black hole candidate GX
339-4 with the Monitor of All-sky X-ray Image (MAXI) / Gas Slit Camera (GSC) in
the high/soft state during the outburst in 2010. All the spectra throughout the
8-month period are well reproduced with a model consisting of multi-color disk
(MCD) emission and its Comptonization component, whose fraction is <= 25% in
the total flux. In spite of the flux variability over a factor of 3, the
innermost disk radius is constant at R_in = 61 +/- 2 km for the inclination
angle of i = 46 deg and the distance of d=8 kpc. This R_in value is consistent
with those of the past measurements with Tenma in the high/soft state. Assuming
that the disk extends to the innermost stable circular orbit of a non-spinning
black hole, we estimate the black hole mass to be M = 6.8 +/- 0.2 M_sun for i =
46 deg and d = 8 kpc, which is consistent with that estimated from the Suzaku
observation of the previous low/hard state. Further combined with the mass
function, we obtain the mass constraint of 4.3 M_sun < M < 13.3 M_sun for the
allowed range of d = 6-15 kpc and i < 60 deg. We also discuss the spin
parameter of the black hole in GX 339-4 by applying relativistic accretion disk
models to the Swift/XRT data.Comment: 9 pages, 8 figures, accepted for publication in PASJ (Suzaku+MAXI
special issue
A Spectral Study of the Black Hole Candidate XTE J1752-223 in the High/Soft State with MAXI, Suzaku and Swift
We report on the X-ray spectral analysis of the black hole candidate XTE\
J1752--223 in the 2009--2010 outburst, utilizing data obtained with the
MAXI/Gas Slit Camera (GSC), the Swift/XRT, and Suzaku, which work
complementarily. As already reported by Nakahira et al. (2010) MAXI monitored
the source continuously throughout the entire outburst for about eight months.
All the MAXI/GSC energy spectra in the high/soft state lasting for 2 months are
well represented by a multi-color disk plus power-law model. The innermost disk
temperature changed from 0.7 keV to 0.4 keV and the disk flux
decreased by an order of magnitude. Nevertheless, the innermost radius is
constant at 41 km, where is the
source distance in units of 3.5 kpc and the inclination. The multi-color
disk parameters obtained with the MAXI/GSC are consistent with those with the
Swift/XRT and Suzaku. The Suzaku data also suggests a possibility that the disk
emission is slightly Comptonized, which could account for broad iron-K features
reported previously. Assuming that the obtained innermost radius represents the
innermost stable circular orbit for a non-rotating black hole, we estimate the
mass of the black hole to be 5.510.28 , where the correction for the stress-free inner boundary condition
and color hardening factor of 1.7 are taken into account. If the inclination is
less than 49 as suggested from the radio monitoring of transient jets
and the soft-to-hard transition in 2010 April occurred at 1--4% of Eddignton
luminosity, the fitting of the Suzaku spectra with a relativistic
accretion-disk model derives constraints on the mass and the distance to be
3.1--55 and 2.3--22 {\rm kpc}, respectively. This confirms that the
compact object in XTE J1752--223 is a black hole.Comment: 12 pages including 7 figures and 4 tables, accepted for publication
in PAS
A Large X-ray Flare from a Single Weak-lined T Tauri Star TWA-7 Detected with MAXI GSC
We present a large X-ray flare from a nearby weak-lined T Tauri star TWA-7
detected with the Gas Slit Camera (GSC) on the Monitor of All-sky X-ray Image
(MAXI). The GSC captured X-ray flaring from TWA-7 with a flux of
ergs cm s in 2--20 keV band during the scan
transit starting at UT 2010-09-07 18:24:30.The estimated X-ray luminosity at
the scan in the energy band is 3 ergs s,indicating that
the event is among the largest X-ray flares fromT Tauri stars.Since MAXI GSC
monitors a target only during a scan transit of about a minute per 92 min
orbital cycle, the luminosity at the flare peak might have been higher than
that detected. At the scan transit, we observed a high X-ray-to-bolometric
luminosity ratio, log = ; i.e., the
X-ray luminosity is comparable to the bolometric luminosity. Since TWA-7 has
neither an accreting disk nor a binary companion, the observed event implies
that none of those are essential to generate such big flares in T Tauri stars.Comment: 4 pages, 2 figures, 1 table accepted for publication in PAS
Peculiarly Narrow SED of GRB 090926B with MAXI and Fermi/GBM
The monitor of all-sky X-ray image (MAXI) Gas Slit Camera (GSC) on the
International Space Station (ISS) detected a gamma-ray burst (GRB) on 2009,
September 26, GRB\,090926B. This GRB had extremely hard spectra in the X-ray
energy range. Joint spectral fitting with the Gamma-ray Burst Monitor on the
Fermi Gamma-ray Space Telescope shows that this burst has peculiarly narrow
spectral energy distribution and is represented by Comptonized blackbody model.
This spectrum can be interpreted as photospheric emission from the low
baryon-load GRB fireball. Calculating the parameter of fireball, we found the
size of the base of the flow cm and Lorentz factor of the plasma , where is a ratio between the total fireball energy and
the energy in the blackbody component of the gamma-ray emission. This is
factor of a few larger, and the Lorentz factor of 110 is smaller by also factor
of a few than other bursts that have blackbody components in the spectra.Comment: 7 pages, 6 figure
Help-seeking intentions for early signs of mental illness and their associated factors: comparison across four kinds of health problems
Abstract Background Failure and delay in initial treatment contact for mental disorders has been recognized as an important public health problem. According to the concept of mental health literacy, recognition of symptoms is crucial to making decisions to seek or not seek professional help. The aims of this study were to investigate the types of health problems for which Japanese adults intend to seek help, their preferred sources of help, and the factors associated with help-seeking intentions. Methods A cross-sectional web-based survey was conducted in June 2014 among Japanese adults aged 20–59 years. A total of 3308 eligible respondents were included in this study. Help-seeking intentions were measured by listing potential sources of help (including ‘would not receive help’) and asking which ones would be chosen in four health conditions indicated by irritability, dizziness, insomnia, and depressed mood, respectively. Results In the case of dizziness, 85.9 % of the participants reported a positive help-seeking intention and 42.7 % gave first priority to seeking help from formal sources. These percentages were smaller in the cases of insomnia (75.4 and 25.0 %), depressed mood (74.9 and 18.7 %), and irritability (72.9 and 0.9 %). Multiple logistic regression analysis revealed that the factors significantly associated with help-seeking intentions were almost identical across the four health problems. In particular, perception of family and friends regarding help-seeking, psychiatric history, contact with people with mental illness, better health literacy, and neighborhood communicativeness were significantly associated with the overall help-seeking intention and also the help-seeking intention from formal sources for all the problems of dizziness, insomnia, and depressed mood. Conclusions The majority of participants indicated their intentions to seek help, but psychological problems (insomnia and depressed mood) were less likely to induce help-seeking intentions than a physical problem (dizziness). Besides developing health literacy skills, community-based interventions for creating a friendly approachable atmosphere and facilitating daily interactions with family, friends, and neighbors may be worth considering as a possible public health strategy for encouraging help-seeking whether for psychological or physical problems
- …