Functional analyses of helix-loop-helix proteins ID1, ID2 and ID3 on neural cell differentiation

Thesis (Ph.D.)--University of Tsukuba, (A), no. 1346, 1995.3.2

Optical Conductivity Study of f Electron States in YbCu2Ge2 at High Pressures to 20 GPa

Optical conductivity [σ(ω)] of YbCu2Ge2 has been measured at external pressures (P) to 20 GPa, to study the P evolution of f electron hybridized states. At P=0, σ(ω) shows a marked mid-infrared (mIR) peak at 0.37 eV, which is due to optical excitations from f14 (Yb2+) state located below the Fermi level. With increasing P, the mIR peak shows significant shifts to lower energy, reaching 0.18 eV at P=20 GPa. This result indicates that the f14 energy level increases toward the Fermi level with P. Such a shift of the f electron level with P has been expected from theoretical considerations, but had never been demonstrated by spectroscopic experiment under high P. The obtained results are also analyzed in terms of the P evolution of the conduction-f electron hybridization

A Chain of Dark Clouds in Projection Against the Galactic Center

In the J, H, and Ks bands survey of the the Galactic Center region over an area of 2deg x 5deg, we have found many dark clouds, among which a distinguished chain of dark clouds can be identified with a quiescent CO cloud. The distances of the clouds is estimated to be 3.2-4.2 kpc, corresponding to the Norma arm by our new method to determine distance to dark clouds using the cumulative number of stars against J-Ks colors. Adopting these estimated distances, the size is about 70 pc in length and the total mass of the cloud is 6x10^4 M_solar. Three compact HII regions harbor in the cloud, indicating that star forming activities are going on at the cores of the quiescent CO cloud on the spiral arm.Comment: 13 pages, 7 figures, accepted for publication in PAS

Visualization of Neural Activity in Insect Brains Using a Conserved Immediate Early Gene, Hr38

Many insects exhibit stereotypic instinctive behavior [1-3], but the underlying neural mechanisms are not well understood due to difficulties in detecting brain activity in freely moving animals. Immediate early genes (IEGs), such as c-fos, whose expression is transiently and rapidly upregulated upon neural activity, are powerful tools for detecting behavior-related neural activity in vertebrates [4, 5]. In insects, however, this powerful approach has not been realized because no conserved IEGs have been identified. Here, we identified Hr38 as a novel IEG that is transiently expressed in the male silkmoth Bombyx mori by female odor stimulation. Using Hr38 expression as an indicator of neural activity, we mapped comprehensive activity patterns of the silkmoth brain in response to female sex pheromones. We found that Hr38 can also be used as a neural activity marker in the fly Drosophila melanogaster. Using Hr38, we constructed a neural activity map of the fly brain that partially overlaps with fruitless (fru)-expressing neurons in response to female stimulation. These findings indicate that Hr38 is a novel and conserved insect neural activity marker gene that will be useful for a wide variety of neuroethologic studies. © 2013 Elsevier Ltd. All rights reserved

A reversible oxygen redox reaction in bulk-type all-solid-state batteries

An all-solid-state lithium battery using inorganic solid electrolytes requires safety assurance and improved energy density, both of which are issues in large-scale applications of lithium-ion batteries. Utilization of high-capacity lithium-excess electrode materials is effective for the further increase in energy density. However, they have never been applied to all-solid-state batteries. Operational difficulty of all-solid-state batteries using them generally lies in the construction of the electrode-electrolyte interface. By the amorphization of Li₂RuO₃ as a lithium-excess model material with Li₂SO₄, here, we have first demonstrated a reversible oxygen redox reaction in all-solid-state batteries. Amorphous nature of the Li₂RuO₃-Li₂SO₄ matrix enables inclusion of active material with high conductivity and ductility for achieving favorable interfaces with charge transfer capabilities, leading to the stable operation of all-solid-state batteries

L-Ascorbate Biosynthesis Involves Carbon Skeleton Rearrangement in the Nematode Caenorhabditis elegans

Ascorbate (AsA) is required as a cofactor and is widely distributed in plants and animals. Recently, it has been suggested that the nematode Caenorhabditis elegans also synthesizes AsA. However, its biosynthetic pathway is still unknown. To further understand AsA biosynthesis in C. elegans, we analyzed the incorporation of the 13C atom into AsA using gas chromatography-mass spectrometry (GC-MS) in worms fed with D-Glc (1-13C)-labeled Escherichia coli. GC-MS analysis revealed that AsA biosynthesis in C. elegans, similarly to that in mammalian systems, involves carbon skeleton rearrangement. The addition of L-gulono-1,4-lactone, an AsA precursor in the mammalian pathway, significantly increased AsA level in C. elegans, whereas the addition of L-galactono-1,4-lactone, an AsA precursor in the plant and Euglena pathway, did not affect AsA level. The suppression of E03H4.3 (an ortholog of gluconolactonase) or the deficiency of F54D5.12 (an ortholog of L-gulono-1,4-lactone oxidase) significantly decreased AsA level in C. elegans. Although N2- and AsA-deficient F54D5.12 knockout mutant worm (tm6671) morphologies and the ratio of collagen to non-collagen protein did not show any significant differences, the mutant worms exhibited increased malondialdehyde levels and reduced lifespan compared with the N2 worms. In conclusion, our findings indicate that the AsA biosynthetic pathway is similar in C. elegans and mammals

Morphological Alterations of the Eccrine Sweat Apparatus in Amputated Feet from Diabetes Mellitus Patients

Several physiological studies have demonstrated decreased or absent thermoregulatory sweating in the distal legs and feet of diabetes patients. Such hypohidrosis in diabetes patients is believed to be a clinical symptom of autonomic neuropathy. Thus, the present study sought to clarify the pathogenesis of structural alterations of the eccrine sweat apparatus in diabetes patients. For this study, we enrolled 17 patients with diabetic ulcers/gangrene who underwent amputation of the foot. Specimens were obtained 30mm from the ulcer/gangrene after amputation using a 6-mm trepan, with 12 normal human skin samples obtained from areas adjacent to pigmented nevi or benign skin tumors on the legs or feet to serve as controls. Numbers and morphological abnormalities of eccrine sweat glands and ducts were assessed by light microscopy. The pathogenesis of morphological alterations was examined by electron microscopy and immunoelectron microscopy of type IV collagen. Rates of disappearance of the lumen, shrunken morphology, and irregular outlines of eccrine sweat glands and ducts were significantly higher or more abundant in diabetes patients than in controls (P = 0.0002〜0.0001). Ultrastructurally, we observed prominent thickening of the basement membranes in eccrine sweat glands, admixed cell debris, and narrowing of the lumenal space. The thickened basement membranes resulted in the shrunken morphology and irregular outlines in eccrine sweat glands and ducts. Immunoelectron microscopy showed immunogold labeling for type IV collagen throughout the thickened basement membrane zone. These morphological alterations of the eccrine sweat apparatus in amputated feet from diabetes patients could be caused by diabetic and/or uremic neuropathy, and at least in part by angiopathy

Outcomes of binocular treatment using a Bangerter occlusion film and computer games in patients with intractable unilateral amblyopia

　To report outcomes following binocular treatment using a Bangerter occlusion filter (BF) and computer games in patients with intractable amblyopia.METHODS: Eight patients (4 boys, mean ± SD age: 8.0 ± 0.8 years) with unilateral amblyopia that did not respond to conventional treatments were studied. They were instructed to play action games for one hour a day while wearing spectacles with an adequate level of BF in front of the non-amblyopic eye so that the visual input became the same between the two eyes. They continued this exercise for eight weeks, and we assessed their visual acuity and spatial sensitivity at baseline, and at 4- and 8-week visits. To confirm the maintenance of efficacy after the treatment, we assessed them again at a 12-week visit.　RESULTS: The mean log MAR at distance improved from 0.32 to 0.24 at the 4-week visit (p < 0.05), and appeared to continue up to eight weeks, but returned to the baseline level at the 12-week visit (four weeks after terminating the treatment). There was no significant improvement in the mean log MAR at near. Contrast sensitivity significantly improved only at three cycles/ degree (p < 0.05), and this effect persisted until the 12-week visit. The distance log MAR at the 12-week visit had a significant correlation with the strength of suppression for the amblyopic eye at baseline (r = 0.71, p < 0.05).　CONCLUSIONS: Binocular treatment improved visual function only in terms of contrast sensitivity at low spatial frequency. Patients who have weak suppression may gain some benefit from this treatment

Constraints on the Intracluster Dust Emission in the Coma Cluster of Galaxies

We have undertaken a search for the infrared emission from the intracluster dust in the Coma cluster of galaxies by the Multiband Imaging Photometer for Spitzer. Our observations yield the deepest mid and far-infrared images of a galaxy cluster ever achieved. In each of the three bands, we have not detected a signature of the central excess component in contrast to the previous report on the detection by Infrared Space Observatory (ISO). We still find that the brightness ratio between 70 and 160 microns shows a marginal sign of the central excess, in qualitative agreement with the ISO result. Our analysis suggests that the excess ratio is more likely due to faint infrared sources lying on fluctuating cirrus foreground. Our observations yield the 2 sigma upper limits on the excess emission within 100 kpc of the cluster center as 5 x 10^-3 MJy/sr, 6 x 10^-2 MJy/sr, and 7 x 10^-2 MJy/sr, at 24, 70, and 160 microns, respectively. These values are in agreement with those found in other galaxy clusters and suggest that dust is deficient near the cluster center by more than 3 orders of magnitude compared to the interstellar medium.Comment: 10 pages, 9 figures, minor changes to match version published in Ap