66 research outputs found
A Search for X-Ray Evidence of a Compact Companion to the Unusual Wolf-Rayet Star HD 50896 (EZ CMa)
We analyze results of a approx.25 ksec ASCA X-ray observation of the unusual Wolf-Rayet star HD 50896 (= EZ CMa). This WN5 star shows optical and ultraviolet variability at a 3.766 day period, which has been interpreted as a possible signature of a compact companion. Our objective was to search for evidence of hard X-rays (greater than or equal to 5 keV) which could be present if the WN5 wind is accreting onto a compact object. The ASCA spectra are dominated by emission below 5 keV and show no significant emission in the harder 5-10 keV range. Weak emission lines are present, and the X-rays arise in an optically thin plasma which spans a range of temperatures from less than or equal to 0.4 keV up to at least approx. 2 keV. Excess X-ray absorption above the interstellar value is present, but the column density is no larger than N(sub H) approx. 10(exp 22)/sq cm. The absorption-corrected X-ray luminosity L(sub x)(0.5 - 10 keV) = 10(exp 32.85) erg/s gives L(sub x)/ L(sub bol) approx. 10(exp -6), a value that is typical of WN stars. No X-ray variability was detected. Our main conclusion is that the X-ray properties of HD 50896 are inconsistent with the behavior expected for wind accretion onto a neutron star or black hole companion. Alternative models based on wind shocks can explain most aspects of the X-ray behavior, and we argue that the hotter plasma near approx. 2 keV could be due to the WR wind shocking onto a normal (nondegenerate) companion
Decreased plasma postheparin lipolytic activity in systemic lupus erythematosus
Plasma postheparin lipolytic activity (PHLA) was measured on 50 patients with systemic lupus erythematosus (SLE). Plasma PHLA was significantly decreased in SLE patients. This decrease was most striking in the acute phase of the disease. There was a close relationship between decreased PHLA and immunologic factors indicative of the acute phase of SLE. These immunologic factors included shaggy antinuclear antibody pattern, low serum complement titer, high DNA antibody titer, mixed cryoglobulin and lumpy glomerular pattern by immunofluorescent staining.</p
Regulatory expression of uncoupling protein 1 and its related genes by endogenous activity of the transforming growth factor‐β family in bovine myogenic cells
Uncoupling protein 1 (UCP1) is responsible for non-shivering thermogenesis, with restricted expression in brown/beige adipocytes in humans and rodents. We have previously shown an unexpected expression of UCP1 in bovine skeletal muscles. This study evaluated factors affecting Ucp1 gene expression in cultured bovine myogenic cells. Myosatellite cells, which were isolated from the bovine musculus longissimus cervicis, were induced to differentiate into myotubes in the presence of 2% horse serum. Previous studies using murine brown/beige adipocytes revealed that Ucp1 expression levels are directly increased by forskolin and all-trans retinoic acid (RA). The transforming growth factor-β (TGF-β)/activin pathway negatively regulated Ucp1 expression, whereas activation of the bone morphogenetic protein (BMP) pathway indirectly increases Ucp1 expression through the stimulation of brown/beige adipogenesis. Neither forskolin nor RA significantly affected Ucp1 mRNA levels in bovine myogenic cells. A-83-01, an inhibitor of the TGF-β/activin pathway, stimulated myogenesis in these cells. A-83-01 significantly increased the expression of some brown fat signature genes such as Pgc-1α, Cox7a1, and Dio2, with a quantitative but not significant increase in the expression of Ucp1. Treatment with LDN-193189, an inhibitor of the BMP pathway, did not affect the differentiation of bovine myosatellite cells. Rather, LDN-193189 increased Ucp1 mRNA levels without modulating the levels of other brown/beige adipocyte-related genes. The current results indicate that the regulation of Ucp1 expression in bovine myogenic cells is distinct from that in murine brown/beige adipocytes, which has been more intensely characterized
Using spin to understand the formation of LIGO's black holes
With the detection of four candidate binary black hole (BBH) mergers by the
Advanced LIGO detectors thus far, it is becoming possible to constrain the
properties of the BBH merger population in order to better understand the
formation of these systems. Black hole (BH) spin orientations are one of the
cleanest discriminators of formation history, with BHs in dynamically formed
binaries in dense stellar environments expected to have spins distributed
isotropically, in contrast to isolated populations where stellar evolution is
expected to induce BH spins preferentially aligned with the orbital angular
momentum. In this work we propose a simple, model-agnostic approach to
characterizing the spin properties of LIGO's BBH population. Using measurements
of the effective spin of the binaries, which is LIGO's best constrained spin
parameter, we introduce a simple parameter to quantify the fraction of the
population that is isotropically distributed, regardless of the spin magnitude
distribution of the population. Once the orientation characteristics of the
population have been determined, we show how measurements of effective spin can
be used to directly constrain the underlying BH spin magnitude distribution.
Although we find that the majority of the current effective spin measurements
are too small to be informative, with LIGO's four BBH candidates we find a
slight preference for an underlying population with aligned spins over one with
isotropic spins (with an odds ratio of 1.1). We argue that it will be possible
to distinguish symmetric and anti-symmetric populations at high confidence with
tens of additional detections, although mixed populations may take
significantly more detections to disentangle. We also derive preliminary spin
magnitude distributions for LIGO's black holes, under the assumption of aligned
or isotropic populations
Clinical and reproductive outcomes of fertility-sparing surgery in stage I epithelial ovarian cancer.
Genome-wide association study revealed novel loci which aggravate asymptomatic hyperuricaemia into gout
Objective
The first ever genome-wide association study (GWAS) of clinically defined gout cases and asymptomatic hyperuricaemia (AHUA) controls was performed to identify novel gout loci that aggravate AHUA into gout.
Methods
We carried out a GWAS of 945 clinically defined gout cases and 1003 AHUA controls followed by 2 replication studies. In total, 2860 gout cases and 3149 AHUA controls (all Japanese men) were analysed. We also compared the ORs for each locus in the present GWAS (gout vs AHUA) with those in the previous GWAS (gout vs normouricaemia).
Results
This new approach enabled us to identify two novel gout loci (rs7927466 of CNTN5 and rs9952962 of MIR302F) and one suggestive locus (rs12980365 of ZNF724) at the genome-wide significance level (p<5.0×10– 8). The present study also identified the loci of ABCG2, ALDH2 and SLC2A9. One of them, rs671 of ALDH2, was identified as a gout locus by GWAS for the first time. Comparing ORs for each locus in the present versus the previous GWAS revealed three ‘gout vs AHUA GWAS’-specific loci (CNTN5, MIR302F and ZNF724) to be clearly associated with mechanisms of gout development which distinctly differ from the known gout risk loci that basically elevate serum uric acid level.
Conclusions
This meta-analysis is the first to reveal the loci associated with crystal-induced inflammation, the last step in gout development that aggravates AHUA into gout. Our findings should help to elucidate the molecular mechanisms of gout development and assist the prevention of gout attacks in high-risk AHUA individuals
HYPERPLASIA OF BROWN ADIPOSE TISSUE AFTER CHRONIC STIMULATION OF β3-ADRENERGIC RECEPTOR IN RATS
When mammals are exposed to a cold environment for a long time, the capacity of nonshivering thermogenesis by brown adipose tissue (BAT) increases in association with the increased expression of some specific proteins and tissue hyperplasia, which are totally dependent on sympathetic innervation to this tissue. To clarify roles of the β-adrenergic mechanism in BAT hyperplasia, the effects of chronic administration of various β-adrenergic agonists on BAT were examined in rats, especially focusing on some agonists to the β3-adrenoceptor which is present specifically in adipocytes. Chronic administration of noradrenaline or isoproterenol for 7-10 days produced a marked increase in the tissue contents of DNA, total protein, mitochondrial uncoupling protein, and insulinregulatable glucose transporter protein. The trophic effects of noradrenaline and isoproterenol were mimicked by chronic administration of β3-adrenergic agonists, such as CL316,243,BRL 26830A, and ICI D7114. These results suggest that the β3-adrenoceptor plays important roles for hyperplasia of BAT, and thereby increasing in the capacity of thermogenesis
Student loans in Japan: Current problems and possible solutions
The Japanese higher education sector has seen increases in tuition with stagnant household incomes in a society where family support for university students has been the norm. Student loans from the government have grown rapidly to sustain the gradual increase in university enrolments. These time-based repayment loans (TBRLs) have created financial hardship for increasing numbers of loan recipients and their families. There is some evidence that prospective students from low-income households are forgoing a university education to avoid student loan debt. The Japanese government has introduced some measures including grants and a partial income-contingent loan (ICL) scheme to help alleviate these problems.
While the ICL scheme is a positive development, this paper shows that it requires further refinement and broader coverage if it is to adequately address the challenges facing higher education financing in Japan. We show that an affordable and universal ICL system could be introduced in Japan that avoids problems with the current partial income-contingent loan scheme and would help alleviate access issues for those from disadvantaged backgrounds. Importantly, the unique features of the Japanese labor market have to be carefully considered, especially the large gender wage gap for married women. By introducing dynamics into modeling graduate earnings and using carefully selected parameters, we show that it is possible to have a universal ICL which achieves a balance between access and affordable repayment with minimal long-run costs to taxpayers.Lorraine Dearden would like to gratefully acknowledge financial assistance received from the ESRC-funded Centre for the Microeconomic
Analysis of Public Policy at IFS (grant RES-544-28-5001) and the
HEFCE and ESRC funded Centre for Global Higher Education at
UCL–IOE (Grant no. ES/M010082/1). Nobuko Nagase would like to
gratefully acknowledge financial assistance received from the Japan
Society for the Promotion of Science fund (KibanC15K03503), and also
by the Joint Usage and Research Center Programs of the Institute of
Economic Research, Hitotsubashi Universit
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