300 research outputs found
Angular power spectrum of gamma-ray sources for GLAST: blazars and clusters of galaxies
Blazars, a beamed population of active galactic nuclei, radiate high-energy
gamma-rays, and thus are a good target for the Gamma Ray Large Area Space
Telescope (GLAST). As the blazars trace the large-scale structure of the
universe, one may observe spatial clustering of blazars. We calculate the
angular power spectrum of blazars that would be detected by GLAST. We show that
we have the best chance of detecting their clustering at large angular scales,
\theta >~ 10 deg, where shot noise is less important, and the dominant
contribution to the correlation comes from relatively low redshift, z <~ 0.1.
The GLAST can detect the correlation signal, if the blazars detected by GLAST
trace the distribution of low-z quasars observed by optical galaxy surveys,
which have the bias of unity. If the bias of blazars is greater than 1.5, GLAST
will detect the correlation signal unambiguously. We also find that GLAST may
detect spatial clustering of clusters of galaxies in gamma-rays. The shape of
the angular power spectrum is different for blazars and clusters of galaxies;
thus, we can separate these two contributions on the basis of the shape of the
power spectrum.Comment: 14 pages, 10 figures; added references; accepted by MNRA
Women’s impressions of their inpatient birth care as provided by family physicians in the Shizuoka Family Medicine Training Program in Japan
Abstract
Background
Even though Japan faces serious challenges in women’s health care such as a rapidly aging population, attrition of obstetrical providers, and a harsh legal climate, few family medicine residency training programs in Japan include training in obstetrics, and the literature lacks research on women’s views of intra-partum pregnancy care by family physicians.
Findings
In this exploratory study, we conducted semi-structured qualitative interviews with five women who received their admission, intrapartum, delivery and discharge care from family medicine residents in the obstetrics ward of a community training hospital. Four women had vaginal births, and one had a Cesarean section. Three were primiparous, and two multiparous. Their ages ranged from 22–33. They found value in family physician medical knowledge and easy communication style, though despite explanation, some had trouble understanding the family physician’s scope of work. These women identified negative aspects of the hospital environment, and wanted more anticipatory guidance about what to expect physically after birth, but were enthusiastic about seeing a family doctor after discharge.
Conclusions
These results demonstrate the feasibility of family medicine residents providing inpatient birth care in a community hospital, and that patients are receptive to family physicians providing that care as well after discharge. Women’s primary concerns relate mostly to hospital environment issues, and better understanding the care family physicians provide. This illustrates-areas for family physicians to work for improvements.http://deepblue.lib.umich.edu/bitstream/2027.42/112408/1/12930_2012_Article_51.pd
A community-based intervention in middle schools to improve HPV vaccination and cervical cancer screening in Japan
Abstract
Aim
Japan has low rates of cervical cancer screening and Human papilloma virus (HPV) vaccination. This research examines the effectiveness of a family medicine resident-led, intervention in increasing knowledge about HPV and cervical cancer in middle school-girls and increasing knowledge and intention to have cervical cancer screening in their mothers.
Methods
We utilized a pre-test/post-test intervention design in three rural middle schools with 7th grade middle school-girls and their mothers. A school-based activity educated girls about HPV and cervical cancer. A home-based activity utilized a homework assignment for girls and their mothers. Pre/post intervention surveys were completed by the girls and their mothers. Major outcomes included changes in knowledge among girls and mothers and barriers to be screened for cervical cancer among mothers.
Results
Sixty-five students and sixty-three mothers completed the study. Two out five mothers were not in compliance with current screening recommendations. Identified barriers included: embarrassment (79%), poor access (56%), fear of having cancer (52%), and cervical cancer screening being an unknown procedure (46%). Forty-four percent of mothers deemed their daughters to be at risk for cervical cancer. Trusted sources of information included: doctors (97%), newspapers/television (89%), government (79%), the Internet (78%), and friends (62%). Student knowledge scores (7-point scale) improved significantly from pre- to post-intervention (4.8 vs. 5.9, p < 0.001). Knowledge scores (14-point scale) among mothers also significantly improved (11.7 vs. 12.0, p = 0.024).
Conclusions
These data suggest a community-based intervention on a sensitive topic by family medicine residents can be implemented in middle schools, can improve school-girls’ knowledge about HPV and cervical cancer, and can reach their mothers. Additional research could examine whether those intending to be screened receive screening and how to reach women who still resist screening.http://deepblue.lib.umich.edu/bitstream/2027.42/109452/1/12930_2014_Article_13.pd
Effect of Toki-Shakuyaku-San on Regional Cerebral Blood Flow in Patients with Mild Cognitive Impairment and Alzheimer's Disease
The aim of this study was to examine the effect of toki-shakuyaku-san (TSS) on mild cognitive impairment (MCI) and Alzheimer's disease (AD) using single-photon emission computed tomography (SPECT). All subjects were administered TSS (7.5 g/day) for eight weeks. SPECT and evaluations using the Mini Mental State Examination (MMSE), Neuropsychiatric Inventory, and Physical Self-Maintenance Scale were performed before and after treatment with TSS. Three patients with MCI and five patients with AD completed the study. No adverse events occurred during the study period. After treatment with TSS, regional cerebral blood flow (rCBF) in the posterior cingulate was significantly higher than that before treatment. No brain region showed a significant decrease in rCBF. TSS treatment also tended to improve the score for orientation to place on the MMSE. These results suggest that TSS could be useful for treatment of MCI and AD
Contribution to the Extragalactic Gamma-ray Background from the Cascades of Very-high Energy Gamma Rays
As very-high--energy photons propagate through the extragalactic background
light (EBL), they interact with the soft photons and initiate electromagnetic
cascades of lower energy photons and electrons. The collective intensity of a
cosmological population emitting at very-high energies (VHE) will be attenuated
at the highest energies through interactions with the EBL and enhanced at lower
energies by the resulting cascade. We calculate the cascade radiation created
by VHE photons produced by blazars and investigate the effects of cascades on
the collective intensity of blazars and the resulting effects on the
extragalactic gamma-ray background. We find that cascade radiation greatly
enhances the collective intensity from blazars at high energies before turning
over due to attenuation. The prominence of the resulting features depends on
the blazar gamma-ray luminosity function, spectral index distribution, and the
model of the EBL. We additionally calculate the cascade radiation from the
distinct spectral sub-populations of blazars, BL Lacertae objects (BL Lacs) and
flat-spectrum radio quasars (FSRQs), finding that the collective intensity of
BL Lacs is considerably more enhanced by cascade radiation than that of the
FSRQs due to their harder spectra. As such, studies of the blazar contribution
to the EGRB by Fermi will have profound implications for the nature of the EBL,
the evolution of blazars, and blazar spectra.Comment: 2009 Fermi Symposium, eConf Proceedings C09112
Dark matter annihilation or unresolved astrophysical sources? Anisotropy probe of the origin of cosmic gamma-ray background
The origin of the cosmic gamma-ray background (CGB) is a longstanding mystery
in high-energy astrophysics. Possible candidates include ordinary astrophysical
objects such as unresolved blazars, as well as more exotic processes such as
dark matter annihilation. While it would be difficult to distinguish them from
the mean intensity data alone, one can use anisotropy data instead. We
investigate the CGB anisotropy both from unresolved blazars and dark matter
annihilation (including contributions from dark matter substructures), and find
that the angular power spectra from these sources are very different. We then
focus on detectability of dark matter annihilation signals using the anisotropy
data, by treating the unresolved blazar component as a known background. We
find that the dark matter signature should be detectable in the angular power
spectrum of the CGB from two-year all-sky observations with the Gamma Ray Large
Area Space Telescope (GLAST), as long as the dark matter annihilation
contributes to a reasonable fraction, e.g., >~ 0.3, of the CGB at around 10
GeV. We conclude that the anisotropy measurement of the CGB with GLAST should
be a powerful tool for revealing the CGB origin, and potentially for the first
detection of dark matter annihilation.Comment: 17 pages, 8 figures; minor revision; accepted by Physical Review
Contribution from unresolved discrete sources to the Extragalactic Gamma-Ray Background (EGRB)
The origin of the extragalactic gamma-ray background (EGRB) is still an open
question, even after nearly forty years of its discovery. The emission could
originate from either truly diffuse processes or from unresolved point sources.
Although the majority of the 271 point sources detected by EGRET (Energetic
Gamma Ray Experiment Telescope) are unidentified, of the identified sources,
blazars are the dominant candidates. Therefore, unresolved blazars may be
considered the main contributor to the EGRB, and many studies have been carried
out to understand their distribution, evolution and contribution to the EGRB.
Considering that gamma-ray emission comes mostly from jets of blazars and that
the jet emission decreases rapidly with increasing jet to line-of-sight angle,
it is not surprising that EGRET was not able to detect many large inclination
angle active galactic nuclei (AGNs). Though Fermi could only detect a few large
inclination angle AGNs in the first three months' survey, it is expected to
detect many such sources in the near future. Since non-blazar AGNs are expected
to have higher density as compared to blazars, these could also contribute
significantly to the EGRB. In this paper we discuss contributions from
unresolved discrete sources including normal galaxies, starburst galaxies,
blazars and off-axis AGNs to the EGRB.Comment: 11 pages, 4 figures, accepted for publication in RA
The Effect of Blazar Spectral Breaks on the Blazar Contribution to the Extragalactic Gamma-ray Background
The spectral shapes of the contributions of different classes of unresolved
gamma-ray emitters can provide insight into their relative contributions to the
extragalactic gamma-ray background (EGB) and the natures of their spectra at
GeV energies. We calculate the spectral shapes of the contributions to the EGB
arising from BL Lacertae type objects (BL Lacs) and flat-spectrum radio quasars
(FSRQs) assuming blazar spectra can be described as broken power laws. We fit
the resulting total blazar spectral shape to the Fermi Large Area Telescope
measurements of the EGB, finding that the best-fit shape reproduces well the
shape of the Fermi EGB for various break scenarios. We conclude that a scenario
in which the contribution of blazars is dominant cannot be excluded on spectral
grounds alone, even if spectral breaks are shown to be common among Fermi
blazars. We also find that while the observation of a featureless (within
uncertainties) power-law EGB spectrum by Fermi does not necessarily imply a
single class of contributing unresolved sources with featureless individual
spectra, such an observation and the collective spectra of the separate
contributing populations determine the ratios of their contributions. As such,
a comparison with studies including blazar gamma-ray luminosity functions could
have profound implications for the blazar contribution to the EGB, blazar
evolution, and blazar gamma-ray spectra and emission.Comment: 8 pages, emulateapj format; 5 figures; accepted for publication in
Ap
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