154 research outputs found
Spatial Dependence, Social Networks, and Economic Structures in Regional Labor Migration
This study empirically analyzes the determinants of regional labor migration in Japan, where small towns are disappearing due to the shortage of labor. Using spatial models of origin-destination flows and considering network effects of labor and economic structures, we obtain results more consistent with the standard migration theory than previous studies. First, unlike previous studies, we find that migration decisions in Japan are based on economic motivations consistent with economic theories. Particularly, unemployment rates in origins and destinations and income in origins are found to be the determinants of labor migration. Second, we report that network effects, which help reduce migration costs, have encouraged relocation of labor. Third, considering spatial weights based on distance, goods flow, and economic structures, we show that neighbors can be most appropriately defined with economic structures; migration
patterns are alike in regions with similar economic structures
Detection of Polarized Broad Emission in the Seyfert 2 Galaxy Mrk 573
We report the discovery of the scattered emission from a hidden broad-line
region (BLR) in a Seyfert 2 galaxy, Mrk 573, based on our recent
spectropolarimetric observation performed at the Subaru Telescope. This object
has been regarded as a type 2 AGN without a hidden BLR by the previous
observations. However, our high quality spectrum of the polarized flux of Mrk
573 shows prominent broad (~3000 km/s) H_alpha emission, broad weak H_beta
emission, and subtle Fe II multiplet emission. Our new detection of these
indications for the presence of the hidden BLR in the nucleus of Mrk 573 is
thought to be owing to the high signal-to-noise ratio of our data, but the
possibility of a time variation of the scattered BLR emission is also
mentioned. Some diagnostic quantities such as the IRAS color, the radio power,
and the line ratio of the emission from the narrow-line region of Mrk 573 are
consistent with the distributions of such quantities of type 2 AGNs with a
hidden BLR. Mrk 573 is thought to be an object whose level of the AGN activity
is the weakest among the type 2 AGNs with a hidden BLR. In terms of the
systematic differences between the type 2 AGNs with and without a hidden BLR,
we briefly comment on an interesting Seyfert 2 galaxy, Mrk 266SW, which may
possess a hidden BLR but has been treated as a type 2 AGNs without a hidden
BLR.Comment: 9 pages including 6 figures, to appear in The Astronomical Journa
Microsatellite loci in Japanese quail and�cross-species amplification in�chicken and�guinea fowl
In line with the Gifu University's initiative to map the Japanese
quail genome, a total of 100 Japanese quail microsatellite markers
isolated in our laboratory were evaluated in a population of 20
unrelated quails randomly sampled from a colony of wild quail
origin. Ninety-eight markers were polymorphic with an average of 3.7
alleles per locus and a mean heterozygosity of 0.423. To determine the
utility of these markers for comparative genome mapping in
Phasianidae, cross-species amplification of all the markers was tested
with chicken and guinea fowl DNA. Amplification products similar in
size to the orthologous loci in quail were observed in 42 loci in
chicken and 20 loci in guinea fowl. Of the cross-reactive markers,
57.1% in chicken and 55.0% in guinea fowl were polymorphic when tested
in 20 birds from their respective populations. Five of 15 markers that
could cross-amplify Japanese quail, chicken, and guinea fowl DNA were
polymorphic in all three species. Amplification of orthologous loci
was confirmed by sequencing 10 loci each from chicken and guinea fowl
and comparing with them the corresponding quail sequence. The
microsatellite markers reported would serve as a useful resource base
for genetic mapping in quail and comparative mapping in Phasianidae
SDSSp J104433.04012502.2 at is Gravitationally Magnified by an Intervening Galaxy
During the course of our optical deep survey program on L emitters at
in the sky area surrounding the quasar SDSSp
J104433.04012502.2 at , we found that a faint galaxy with (AB)
is located at \timeform{1".9} southwest of the quasar. Its
broad-band color properties from to suggest that the galaxy is
located at a redshift of -- 2.5. This is consistent with no strong
emission line in our optical spectroscopy. Since the counter image of the
quasar cannot be seen in our deep optical images, the magnification factor
seems not to be very high. Our modest estimate is that this quasar is
gravitationally magnified by a factor of 2.Comment: 11 pages, 5 figures, PASJ, in pres
On the Origin of Lyman- Blobs at High Redshift: Kinematic Evidence for a Hyperwind Galaxy at z = 3.1
We present deep optical spectroscopy of an extended Ly emission-line
blob located in an over-dense region at redshift ; `blob 1' of
Steidel et al. (2000). The origin of such Ly blobs has been debated for
some time; two of the most plausible models are (1) that it comes from a
dust-enshrouded, extreme starburst galaxy with a large-scale galactic outflow
(superwind/hyperwind) or (2) that it is the cooling radiation of proto-galaxies
in dark matter halos. Examination of the kinematic properties of the Ly
emission-line gas should allow us to determine its nature. With this
motivation, we performed optical spectroscopy of `blob 1' using the Subaru
Telescope, and found that its kinematic properties can be well explained in
terms of superwind activity.Comment: 12 pages, including 4 figures, accepted for publication in ApJ
Co-morbidity of progressive supranuclear palsy and amyotrophic lateral sclerosis : a clinical-pathological case report
Background: The coexistence of distinct neurodegenerative diseases in single cases has recently attracted greater attention. The phenotypic co-occurrence of progressive supranuclear palsy (PSP) and amyotrophic lateral sclerosis (ALS) has been documented in several cases. That said, the clinicopathological comorbidity of these two diseases has not been demonstrated.
Case presentation: A 77-year-old man presented with gait disturbance for 2 years, consistent with PSP with progressive gait freezing. At 79 years old, he developed muscle weakness compatible with ALS. The disease duration was 5 years after the onset of PSP and 5months after the onset of ALS. Neuropathological findings demonstrated the coexistence of PSP and ALS. Immunohistochemical examination confirmed 4-repeat tauopathy, including globose-type neurofibrillary tangles, tufted astrocytes, and oligodendroglial coiled bodies as well as TAR DNA-binding protein 43 kDa pathology in association with upper and lower motor neuron degeneration. Immunoblotting showed hyperphosphorylated full-length 4-repeat tau bands (64 and 68 kDa) and C-terminal fragments (33 kDa), supporting the diagnosis of PSP and excluding other parkinsonian disorders, such as corticobasal degeneration. Genetic studies showed no abnormalities in genes currently known to be related to ALS or PSP.
Conclusions: Our case demonstrates the clinicopathological comorbidity of PSP and ALS in a sporadic patient. The possibility of multiple proteinopathies should be considered when distinct symptoms develop during the disease course
- …