579 research outputs found
Temperature Response Comparison of Controlled and Field Environments for Four Tropical Grasses
Tropical grasses are cultivated mostly as annuals in the warm region of SW Japan. They have a long-term sowing time after harvesting temperate Italian ryegrass. We compared the early growth of tropical grasses in a controlled environment vs. field data at 2 sowing times to determine their temperate response
Gastric Inflammatory Fibroid Polyp Treated by Endoscopic Submucosal Dissection
The endoscopic examination of a 64-year-old male patient revealed a gastric submucosal tumor in the anterior wall of the gastric antrum. The lesion increased in diameter to 25 mm and was resected completely with endoscopic submucosal dissection (ESD). Histological examination of the submucosal tumor gave a diagnosis of an inflammatory fibroid polyp (IFP). It is suggested that ESD may be an effective and safe therapy for gastric submucosal tumors
Submillimeter detection of the Sunyaev -- Zel'dovich effect toward the most luminous X-ray cluster at z=0.45
We report on the detection of the Sunyaev -- Zel'dovich (SZ) signals toward
the most luminous X-ray cluster RXJ1347-1145 at Nobeyama Radio Observatory (21
and 43 GHz) and at James Clerk Maxwell Telescope (350 GHz). In particular the
latter is the first successful detection of the SZ temperature increment in the
submillimeter band which resolved the profile of a cluster of galaxies. Both
the observed spectral dependence and the radial profile of the SZ signals are
fully consistent with those expected from the X-ray observation of the cluster.
The combined analysis of 21GHz and 350GHz data reproduces the temperature and
core-radius of the cluster determined with the ROSAT and ASCA satellites when
we adopt the slope of the density profile from the X-ray observations.
Therefore our present data provide the strongest and most convincing case for
the detection of the submillimeter SZ signal from the cluster, as well as in
the Rayleigh -- Jeans regime. We also discuss briefly the cosmological
implications of the present results.Comment: 11 pages, The Astrophysical Journal (Letters), in pres
Galactic Wind in the Nearby Starburst Galaxy NGC 253 Observed with the Kyoto3DII Fabry-Perot Mode
We have observed the central region of the nearby starburst galaxy NGC 253
with the Kyoto Tridimensional Spectrograph II (Kyoto3DII) Fabry-Perot mode in
order to investigate the properties of its galactic wind. Since this galaxy has
a large inclination, it is easy to observe its galactic wind. We produced the
Ha, [N II]6583, and [S II]6716,6731 images, as well as those line ratio maps.
The [N II]/Ha ratio in the galactic wind region is larger than those in H II
regions in the galactic disk. The [N II]/Ha ratio in the southeastern filament,
a part of the galactic wind, is the largest and reaches about 1.5. These large
[N II]/Ha ratios are explained by shock ionization/excitation. Using the [S
II]/Ha ratio map, we spatially separate the galactic wind region from the
starburst region. The kinetic energy of the galactic wind can be sufficiently
supplied by supernovae in a starburst region in the galactic center. The shape
of the galactic wind and the line ratio maps are non-axisymmetric about the
galactic minor axis, which is also seen in M82. In the [N II]6583/[S
II]6716,6731 map, the positions with large ratios coincide with the positions
of star clusters found in the Hubble Space Telescope (HST) observation. This
means that intense star formation causes strong nitrogen enrichment in these
regions. Our unique data of the line ratio maps including [S II] lines have
demonstrated their effectiveness for clearly distinguishing between shocked gas
regions and starburst regions, determining the extent of galactic wind and its
mass and kinetic energy, and discovering regions with enhanced nitrogen
abundance.Comment: 22 pages, 5 figures, 1 table, accepted for publication in Ap
Correlated Alterations in Serotonergic and Dopaminergic Modulations at the Hippocampal Mossy Fiber Synapse in Mice Lacking Dysbindin
Dysbindin-1 (dystrobrevin-binding protein 1, DTNBP1) is one of the promising schizophrenia susceptibility genes. Dysbindin protein is abundantly expressed in synaptic regions of the hippocampus, including the terminal field of the mossy fibers, and this hippocampal expression of dysbindin is strongly reduced in patients with schizophrenia. In the present study, we examined the functional role of dysbindin in hippocampal mossy fiber-CA3 synaptic transmission and its modulation using the sandy mouse, a spontaneous mutant with deletion in the dysbindin gene. Electrophysiological recordings were made in hippocampal slices prepared from adult male sandy mice and their wild-type littermates. Basic properties of the mossy fiber synaptic transmission in the mutant mice were generally normal except for slightly reduced frequency facilitation. Serotonin and dopamine, two major neuromodulators implicated in the pathophysiology of schizophrenia, can potentiate mossy fiber synaptic transmission probably via an increase in cAMP levels. Synaptic potentiation induced by serotonin and dopamine was very variable in magnitude in the mutant mice, with some mice showing prominent enhancement as compared with the wild-type mice. In addition, the magnitude of potentiation induced by these monoamines significantly correlated with each other in the mutant mice, indicating that a subpopulation of sandy mice has marked hypersensitivity to both serotonin and dopamine. While direct activation of the cAMP cascade by forskolin induced robust synaptic potentiation in both wild-type and mutant mice, this forskolin-induced potentaition correlated in magnitude with the serotonin-induced potentiation only in the mutant mice, suggesting a possible change in coupling of receptor activation to downstream signaling. These results suggest that the dysbindin deficiency could be an essential genetic factor that causes synaptic hypersensitivity to dopamine and serotonin. The altered monoaminergic modulation at the mossy fiber synapse could be a candidate pathophysiological basis for impairment of hippocampus-dependent brain functions in schizophrenia
Mice with cleavage-resistant N-cadherin exhibit synapse anomaly in the hippocampus and outperformance in spatial learning tasks
N-cadherin is a homophilic cell adhesion molecule that stabilizes excitatory synapses, by connecting pre- and post-synaptic termini. Upon NMDA receptor (NMDAR) activation by glutamate, membrane-proximal domains of N-cadherin are cleaved serially by a-disintegrin-and-metalloprotease 10 (ADAM10) and then presenilin 1(PS1, catalytic subunit of the γ-secretase complex). To assess the physiological significance of the initial N-cadherin cleavage, we engineer the mouse genome to create a knock-in allele with tandem missense mutations in the mouse N-cadherin/Cadherin-2 gene (Cdh2 R714G, I715D, or GD) that confers resistance on proteolysis by ADAM10 (GD mice). GD mice showed a better performance in the radial maze test, with significantly less revisiting errors after intervals of 30 and 300 s than WT, and a tendency for enhanced freezing in fear conditioning. Interestingly, GD mice reveal higher complexity in the tufts of thorny excrescence in the CA3 region of the hippocampus. Fine morphometry with serial section transmission electron microscopy (ssTEM) and three-dimensional (3D) reconstruction reveals significantly higher synaptic density, significantly smaller PSD area, and normal dendritic spine volume in GD mice. This knock-in mouse has provided in vivo evidence that ADAM10-mediated cleavage is a critical step in N-cadherin shedding and degradation and involved in the structure and function of glutamatergic synapses, which affect the memory function
"Dark" GRB 080325 in a Dusty Massive Galaxy at z ~ 2
We present optical and near infrared observations of GRB 080325 classified as
a "Dark GRB". Near-infrared observations with Subaru/MOIRCS provided a clear
detection of afterglow in Ks band, although no optical counterpart was
reported. The flux ratio of rest-wavelength optical to X-ray bands of the
afterglow indicates that the dust extinction along the line of sight to the
afterglow is Av = 2.7 - 10 mag. This large extinction is probably the major
reason for optical faintness of GRB 080325. The J - Ks color of the host
galaxy, (J - Ks = 1.3 in AB magnitude), is significantly redder than those for
typical GRB hosts previously identified. In addition to J and Ks bands, optical
images in B, Rc, i', and z' bands with Subaru/Suprime-Cam were obtained at
about one year after the burst, and a photometric redshift of the host is
estimated to be z_{photo} = 1.9. The host luminosity is comparable to L^{*} at
z \sim 2 in contrast to the sub-L^{*} property of typical GRB hosts at lower
redshifts. The best-fit stellar population synthesis model for the host shows
that a large dust extinction (Av = 0.8 mag) attributes to the red nature of the
host and that the host galaxy is massive (M_{*} = 7.0 \times 10^{10} Msun)
which is one of the most massive GRB hosts previously identified. By assuming
that the mass-metallicity relation for star-forming galaxies at z \sim 2 is
applicable for the GRB host, this large stellar mass suggests the high
metallicity environment around GRB 080325, consistent with inferred large
extinction.Comment: 22 pages, 10 figures, accepted for publication in The Astrophysical
Journa
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