91 research outputs found

    The first determination of the actinide Th abundance for a red giant of the Ursa Minor dwarf galaxy

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    The Thorium abundance for the red giant COS82 in the Ursa Minor dwarf spheroidal galaxy is determined based on a high resolution spectrum. This is the first detection of actinides in an extra Galactic object. A detailed abundance pattern is determined for 12 other neutron-capture elements from the atomic number 39 to 68. These elements are significantly over-abundant with respect to other metals like Fe (> 1 dex) and their abundance pattern agrees well with those of the r-process-enhanced, very metal-poor stars known in the Galactic halo, while the metallicity of this object ([Fe/H] ~ -1.5) is much higher than these field stars ([Fe/H] ~ -3.0). The results indicate that the mechanism and the astrophysical site that are responsible for neutron-capture elements in COS82 is similar to that for field r-process-enhanced stars, while the condition of low mass star formation is quite different. An estimate of the age of this object based on the Th abundance ratio is discussed.Comment: 5 pages, 2 figures, 1 table, to appear in PAS

    The Effects of Self-directed Home Exercise with Serial Telephone Contacts on Physical Functions and Quality of Life in Elderly People at High Risk of Locomotor Dysfunction

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    Exercise is essential for maintaining quality of life (QOL) in elderly individuals. However, adherence to exercise programs is low. Here, we assessed the effectiveness of a self-directed home exercise program with serial telephone contacts to encourage exercise adherence among elderly individuals at high risk of locomotor dysfunction. We recruited community-dwelling adults (ァ65 years) in Niigata, Japan, who were targets of the long-term care prevention project for locomotor dysfunction but did not participate in the government-sponsored prevention programs. The study was conducted from November 2011 to October 2012. Participants received exercise instruction and performed exercises independently for 3 months with serial telephone contacts. The single-leg stance and five-times sit-to-stand tests were used to assess physical function. The SF-8 was used to measure health-related QOL. Ninety-seven participants were enrolled in the study, representing 2.5オ of eligible people;87 completed the intervention. Scores from physical function tests were significantly improved by the intervention, as were 7 of eight SF-8 subscales. Adherence was 85.4オ for the single-leg standing exercise and 82.1オ for squatting. Thus, self-directed home exercise with serial telephone contacts improved physical function and health-related QOL, representing a promising model for preventing the need for long-term care due to locomotor dysfunction

    Proteasome-dependent decrease in Akt by growth factors in vascular smooth muscle cells

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    AbstractAkt is activated by growth factors to regulate various aspects of vascular smooth muscle cell function. Platelet-derived growth factor (PDGF) and insulin-like growth factor-1 activated Akt in vascular smooth muscle cells with a rapid reduction of total Akt protein that lasted for several hours. The downregulation of Akt required phosphatidylinositol 3-kinase activity, but not intrinsic Akt activity. The downregulation of Akt was abrogated by MG-132, a proteasome inhibitor, but not by inhibitors of calpain or cathepsins. Akt was found in ubiquitin immune complex after PDGF treatment. Proteasome-dependent degradation of Akt may provide a counter-regulatory mechanism against overactivation of Akt

    Quantification of Local Morphodynamics and Local GTPase Activity by Edge Evolution Tracking

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    Advances in time-lapse fluorescence microscopy have enabled us to directly observe dynamic cellular phenomena. Although the techniques themselves have promoted the understanding of dynamic cellular functions, the vast number of images acquired has generated a need for automated processing tools to extract statistical information. A problem underlying the analysis of time-lapse cell images is the lack of rigorous methods to extract morphodynamic properties. Here, we propose an algorithm called edge evolution tracking (EET) to quantify the relationship between local morphological changes and local fluorescence intensities around a cell edge using time-lapse microscopy images. This algorithm enables us to trace the local edge extension and contraction by defining subdivided edges and their corresponding positions in successive frames. Thus, this algorithm enables the investigation of cross-correlations between local morphological changes and local intensity of fluorescent signals by considering the time shifts. By applying EET to fluorescence resonance energy transfer images of the Rho-family GTPases Rac1, Cdc42, and RhoA, we examined the cross-correlation between the local area difference and GTPase activity. The calculated correlations changed with time-shifts as expected, but surprisingly, the peak of the correlation coefficients appeared with a 6–8 min time shift of morphological changes and preceded the Rac1 or Cdc42 activities. Our method enables the quantification of the dynamics of local morphological change and local protein activity and statistical investigation of the relationship between them by considering time shifts in the relationship. Thus, this algorithm extends the value of time-lapse imaging data to better understand dynamics of cellular function

    Chemical Abundances in the Secondary Star of the Black Hole Binary V4641 Sagittarii (SAX J1819.3-2525)

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    We report on detailed spectroscopic studies performed for the secondary star in the black hole binary (micro-quasar) V4641 Sgr in order to examine its surface chemical composition and to see if its surface shows any signature of pollution by ejecta from a supernova explosion. High-resolution spectra of V4641 Sgr observed in the quiescent state in the blue-visual region are compared with those of the two bright well-studied B9 stars (14 Cyg and ν\nu Cap) observed with the same instrument. The effective temperature of V4641 Sgr (10500 ±\pm 200 K) is estimated from the strengths of He~{\sc i} lines, while its rotational velocity, v\it v sin i\it i (95 ±\pm 10 km s1{}^{-1}), is estimated from the profile of the Mg~{\sc ii} line at 4481 \AA. We obtain abundances of 10 elements and find definite over-abundances of N (by 0.8 dex or more) and Na (by 0.8 dex) in V4641 Sgr. From line-by-line comparisons of eight other elements (C, O, Mg, Al, Si, Ti, Cr, and Fe) between V4641 Sgr and the two reference stars, we conclude that there is no apparent difference in the abundances of these elements between V4641 Sgr and the two normal late B-type stars, which have been reported to have solar abundances. An evolutionary model of a massive close binary system has been constructed to explain the abundances observed in V4641 Sgr. The model suggests that the progenitor of the black hole forming supernova was as massive as ~ 35 Msun on the main-sequence and, after becoming a ~ 10 Msun He star, underwent "dark" explosion which ejected only N and Na-rich outer layer of the He star without radioactive 56^{56}Ni.Comment: 13 pages, 14 figures. Accepted for publication in the PASJ: Publications of the Astronomical Society of Japa

    A different distribution of corticotropin releasing factor and arginine vasopressin contents in the hypothalamic nuclei after estrogen administration.

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    The distribution of corticotropin releasing factor (CRF) and arginine vasopressin (AVP) in hypothalamic nuclei were examined in control and estrogen-treated female rats. CRF activity was measured using monolayer cultured rat anterior pituitary cells and AVP by radioimmunoassay. Hypothalamic nuclei were punched out according to the method of Palkovits. The distribution of CRF activity in 5 different hypothalamic nuclei was similar to that of AVP in intact female rats. CRF activity in hypothalamic nuclei, pituitary ACTH content and plasma ACTH levels in estrogen-treated rats were not significantly different from those in control rats. However, significant elevation of AVP content was observed in the supraoptic and paraventricular nuclei of estrogen-treated rats. These results indicate that CRF and AVP are distributed in similar hypothalamic nuclei, but that they are not identical.</p

    Evidence for a companion to BM Gem, a silicate carbon star

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    Balmer and Paschen continuum emission as well as Balmer series lines of P Cygni-type profile from H_gamma through H_23 are revealed in the violet spectra of BM Gem, a carbon star associated with an oxygen-rich circumstellar shell (`silicate carbon star') observed with the high dispersion spectrograph (HDS) on the Subaru telescope. The blue-shifted absorption in the Balmer lines indicates the presence of an outflow, the line of sight velocity of which is at least 400 km s^-1, which is the highest outflow velocity observed to date in a carbon star. We argue that the observed unusual features in BM Gem are strong evidence for the presence of a companion, which should form an accretion disk that gives rise to both an ionized gas region and a high velocity, variable outflow. The estimated luminosity of ~0.2 (0.03-0.6) L_sun for the ionized gas can be maintained by a mass accretion rate to a dwarf companion of ~10^-8 M_sun yr^-1, while ~10^-10 M_sun yr^-1 is sufficient for accretion to a white dwarf companion. These accretion rates are feasible for some detached binary configurations on the basis of the Bond-Hoyle type accretion process. We concluded that the carbon star BM Gem is in a detached binary system with a companion of low mass and low luminosity. However, we are unable to determine whether this companion object is a dwarf or a white dwarf. The upper limits for binary separation are 210 AU and 930 AU for a dwarf and a white dwarf, respectively. We also note that the observed features of BM Gem mimic those of Mira (omi Cet), which may suggest actual similarities in their binary configurations and circumstellar structures.Comment: 11 pages, 2 figures, 1 table, accepted for publication in Ap

    Heart Failure-Inducible Gene Therapy Targeting Protein Phosphatase 1 Prevents Progressive Left Ventricular Remodeling

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    BACKGROUND: The targeting of Ca(2+) cycling has emerged as a potential therapy for the treatment of severe heart failure. These approaches include gene therapy directed at overexpressing sarcoplasmic reticulum (SR) Ca(2+) ATPase, or ablation of phospholamban (PLN) and associated protein phosphatase 1 (PP1) protein complexes. We previously reported that PP1β, one of the PP1 catalytic subunits, predominantly suppresses Ca(2+) uptake in the SR among the three PP1 isoforms, thereby contributing to Ca(2+) downregulation in failing hearts. In the present study, we investigated whether heart-failure-inducible PP1β-inhibition by adeno-associated viral-9 (AAV9) vector mediated gene therapy is beneficial for preventing disease progression in genetic cardiomyopathic mice. METHODS: We created an adeno-associated virus 9 (AAV9) vector encoding PP1β short-hairpin RNA (shRNA) or negative control (NC) shRNA. A heart failure inducible gene expression system was employed using the B-type natriuretic protein (BNP) promoter conjugated to emerald-green fluorescence protein (EmGFP) and the shRNA sequence. AAV9 vectors (AAV9-BNP-EmGFP-PP1βshRNA and AAV9-BNP-EmGFP-NCshRNA) were injected into the tail vein (2×10(11) GC/mouse) of muscle LIM protein deficient mice (MLPKO), followed by serial analysis of echocardiography, hemodynamic measurement, biochemical and histological analysis at 3 months. RESULTS: In the MLPKO mice, BNP promoter activity was shown to be increased by detecting both EmGFP expression and the induced reduction of PP1β by 25% in the myocardium. Inducible PP1βshRNA delivery preferentially ameliorated left ventricular diastolic function and mitigated adverse ventricular remodeling. PLN phosphorylation was significantly augmented in the AAV9-BNP-EmGFP-PP1βshRNA injected hearts compared with the AAV9-BNP-EmGFP-NCshRNA group. Furthermore, BNP production was reduced, and cardiac interstitial fibrosis was abrogated at 3 months. CONCLUSION: Heart failure-inducible molecular targeting of PP1β has potential as a novel therapeutic strategy for heart failure
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