912 research outputs found
Comment on ``Local dimer-adatom stacking fault structures from 3x3 to 13x13 along Si(111)-7x7 domain boundaries''
Zhao et al. [Phys.Rev.B 58, 13824 (1998)] depicted several atomic structures
of domain boundaries on a Si(111) surface and criticized the article by the
present author and the co-workers. I will point out that their criticism is
incorrect and their structure models have no consistency.Comment: 2 pages. Physical Review B, to appea
Clustering of Emission-line Stars in the W5E HII region
We have made a new survey of emission-line stars in the W5E HII region to
investigate the population of PMS stars near the OB stars by using the Wide
Field Grism Spectrograph 2 (WFGS2). A total of 139 H-alpha emission stars were
detected and their g'i'-photometry was performed. The spatial distribution of
them shows three aggregates, i.e., two aggregates near the bright-rimmed clouds
at the edge of W5E HII region (BRC 13 and BRC 14) and one near the exciting O7V
star. The age and mass of each H-alpha star were estimated from the extinction
corrected color-magnitude diagram and theoretical evolutionary tracks. We
found, for the first time in this region, that the young stars near the
exciting star are systematically older (4 Myr) than those near the edge of the
HII region (1 Myr). This result supports that the formation of stars proceed
sequentially from the center of HII region to the eastern bright rim. We
further suggest a possibility that the birth of low mass stars near the
exciting star of HII region precede the production of massive OB stars in the
pre-existing molecular cloud.Comment: 16 pages, 7 figures, 3 tables, accepted for publication in PAS
Cooperative contributions of Interferon regulatory factor 1 (IRF1) and IRF8 to interferon-γ-mediated cytotoxic effects on oligodendroglial progenitor cells
<p>Abstract</p> <p>Background</p> <p>Administration of exogenous interferon-γ (IFNγ) aggravates the symptoms of multiple sclerosis (MS), whereas interferon-β (IFNβ) is used for treatment of MS patients. We previously demonstrated that IFNγ induces apoptosis of oligodendroglial progenitor cells (OPCs), suggesting that IFNγ is more toxic to OPCs than IFNβ. Thus we hypothesized that a difference in expression profiles between IFNγ-inducible and IFNβ-inducible genes in OPCs would predict the genes responsible for IFNγ-mediated cytotoxic effects on OPCs. We have tested this hypothesis particularly focusing on the interferon regulatory factors (IRFs) well-known transcription factors up-regulated by IFNs.</p> <p>Methods</p> <p>Highly pure primary rat OPC cultures were treated with IFNγ and IFNβ. Cell death and proliferation were assessed by MTT reduction, caspse-3-like proteinase activity, Annexin-V binding, mitochondrial membrane potential, and BrdU-incorporation. Induction of all nine IRFs was comprehensively compared by quantitative PCR between IFNγ-treated and IFNβ-treated OPCs. IRFs more strongly induced by IFNγ than by IFNβ were selected, and tested for their ability to induce OPC apoptosis by overexpression and by inhibition by dominant-negative proteins or small interference RNA either in the presence or absence of IFNγ.</p> <p>Results</p> <p>Unlike IFNγ, IFNβ did not induce apoptosis of OPCs. Among nine IRFs, IRF1 and IRF8 were preferentially up-regulated by IFNγ. In contrast, IRF7 was more robustly induced by IFNβ than by IFNγ. Overexpressed IRF1 elicited apoptosis of OPCs, and a dominant negative IRF1 protein partially protected OPCs from IFNγ-induced apoptosis, indicating a substantial contribution of IRF1 to IFNγ-induced OPC apoptosis. On the other hand, overexpression of IRF8 itself had only marginal proapoptotic effects. However, overexpressed IRF8 enhanced the IFNγ-induced cytotoxicity and the proapoptotic effect of overexpressed IRF1, and down-regulation of IRF8 by siRNA partially but significantly reduced preapoptotic cells after treatment with IFNγ, suggesting that IRF8 cooperatively enhances IFNγ-induced OPC apoptosis.</p> <p>Conclusions</p> <p>This study has identified that IRF1 and IRF8 mediate IFNγ-signaling leading to OPC apoptosis. Therapies targeting at these transcription factors and their target genes could reduce IFNγ-induced OPC loss and thereby enhance remyelination in MS patients.</p
A method to measure a relative transverse velocity of source-lens-observer system using gravitational lensing of gravitational waves
Gravitational waves propagate along null geodesics like light rays in the
geometrical optics approximation, and they may have a chance to suffer from
gravitational lensing by intervening objects, as is the case for
electromagnetic waves. Long wavelength of gravitational waves and compactness
of possible sources may enable us to extract information in the interference
among the lensed images. We point out that the interference term contains
information of relative transverse velocity of the source-lens-observer system,
which may be obtained by possible future space-borne gravitational wave
detectors such as BBO/DECIGO.Comment: 27 pages, 9 figures. Accepted for publication in Physical Review
Neoliberal Capitalism Reconsidered: Reviewing D. Kotz's Recent Work
Re-expanded inequality of distribution of wealth and income in major economies in the era of neoliberalism, as impressively revealed statistically by T. Piketty's Capital in the Twenty-First Century (2014), has globally reactivated a series of political movements demanding revival of democratic socialism for working people. To understand the historical significance and rationality of such a new political tide, we need to cooperate on synthetic critical analyses of neoliberal capitalism. By reviewing D. Kotz's The Rise and Fall of Neoliberal Capitalism (2015), this article would discuss the following topics: (1) characteristic approach of SSA (Social Structure of Accumulation) theory to neoliberalism, (2) the impact of information technology (IT) to the restructure of capital-labor relations, (3) Japan's position in the world of neoliberalism, and (4) alternatives for the future
FROM THE SUBPRIME TO THE SOVEREIGN CRISIS: WHY KEYNESIANISM DOES NOT WORK
This article analyzes the recent global economic crisis in the central capitalist
economies from the viewpoint of Marxian political economy. In the first section, it
examines the so-called sovereign crisis concerning the deepening fiscal crisis of
the states, particularly serious now in the Euro zone. Although there is a structural
problem causing the sovereign crisis in peripheral countries in the Euro zone, the
menace of the sovereign crisis is not limited to this region. Both the US and Japanese
governments also suffer from cumulative state debt in all its features. In the second
section, it emphasizes the significance of the continuity of economic disaster from
the subprime to the sovereign crisis as a structured debt crisis in the financialized
capitalism of our age. This encompasses structural debt crises of labor power, financial
institutions, and the states. In the third section, the article shows why renewed
Keynesian and social democratic policies in 2009-10 could not be maintained, after
restoring economic growth in major economies, but were shifted back to neo-liberal
austerity policies.
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