652 research outputs found
Analytic Solutions of the Regge-Wheeler Equation and the Post-Minkowskian Expansion
Analytic solutions of the Regge-Wheeler equation are presented in the form of
series of hypergeometric functions and Coulomb wave functions which have
different regions of convergence. Relations between these solutions are
established. The series solutions are given as the Post-Minkowskian expansion
with respect to a parameter , being the mass of
black hole. This expansion corresponds to the post-Newtonian expansion when
they are applied to the gravitational radiation from a particle in circular
orbit around a black hole. These solutions can also be useful for numerical
computations.Comment: 22 page
Absorption rate of the Kerr-de Sitter black hole and the Kerr-Newman-de Sitter black hole
By using an analytic solution of the Teukolsky equation in the Kerr-de Sitter
and Kerr-Newman-de Sitter geometries, an analytic expression of the absorption
rate formulae for these black holes is calculated.Comment: 11 pages, LaTeX. Several typos are correcte
Analytic Solutions of the Teukolsky Equation and their Low Frequency Expansions
Analytic solutions of the Teukolsky equation in Kerr geometries are presented
in the form of series of hypergeometric functions and Coulomb wave functions.
Relations between these solutions are established. The solutions provide a very
powerful method not only for examining the general properties of solutions and
physical quantities when they are applied to, but also for numerical
computations. The solutions are given in the expansion of a small parameter
, being the mass of black hole, which corresponds
to Post-Minkowski expansion by and to post-Newtonian expansion when they
are applied to the gravitational radiation from a particle in circular orbit
around a black hole. It is expected that these solutions will become a powerful
weapon to construct the theoretical template towards LIGO and VIRGO projects.Comment: 24 pages, minor modification
Analytic Solutions of Teukolsky Equation in Kerr-de Sitter and Kerr-Newman-de Sitter Geometries
The analytic solution of Teukolsky equation in Kerr-de Sitter and
Kerr-Newman-de Sitter geometries is presented and the properties of the
solution are examined. In particular, we show that our solution satisfies the
Teukolsky-Starobinsky identities explicitly and fix the relative normalization
between solutions with the spin weight and .Comment: 24 pages, LaTe
Xk-Related Protein 8 and CED-8 Promote Phosphatidylserine Exposure in Apoptotic Cells
アポトーシス時のリン脂質暴露に関与する因子の同定. 京都大学プレスリリース. 2013-07-12.A classic feature of apoptotic cells is the cell-surface exposure of phosphatidylserine (PtdSer) as an "eat me" signal for engulfment. We show that the Xk-family protein Xkr8 mediates PtdSer exposure in response to apoptotic stimuli. Mouse Xkr8(-/-) cells or human cancer cells in which Xkr8 expression was repressed by hypermethylation failed to expose PtdSer during apoptosis and were inefficiently engulfed by phagocytes. Xkr8 was activated directly by caspases and required a caspase-3 cleavage site for its function. CED-8, the only Caenorhabditis elegans Xk-family homolog, also promoted apoptotic PtdSer exposure and cell-corpse engulfment. Thus, Xk-family proteins have evolutionarily conserved roles in promoting the phagocytosis of dying cells by altering the phospholipid distribution in the plasma membrane
An Analysis of Factors that Exacerbate Asthma, Based on a Japanese Questionnaire
ABSTRACTBackgroundIt is known that a wide variety of factors exacerbate asthma; however, few studies have investigated the factors that exacerbate asthma from a patient's perspective. The aim of this study was to analyze the factors that exacerbate asthma, based on a questionnaire completed by asthma patients in Niigata Prefecture.MethodsBased on questionnaires given to 3085 patients who visited the medical institutes in the Niigata Prefecture monthly from September through October 2006, groups stratified by sex, age, disease type and disease severity, were analyzed for factors contributing to asthma exacerbation, as described in the guideline of the Japanese Society of Allergology.ResultsThe leading exacerbating factor chosen by patients was a change in the weather, followed by smoking, allergen exposure, fatigue, stimulants, and air pollutants. Respiratory infection, widely recognized as a critical factor of severe exacerbation, was ranked seventh. Allergen exposure and air pollutants were prominent in younger individuals, whereas respiratory infection tended to be more common in elderly subjects. Allergen exposure, air pollutants, and exercise were significantly more common in atopic-type patients, in contrast with respiratory infection in non-atopic-type patients. According to multiple regression analysis, poor asthma control during the last one year was associated with changes in the weather, whereas the non-atopic disease type was related to exacerbation by respiratory infection. Current smoking was associated with both factors.ConclusionsMany factors exacerbate asthma, depending on the individual case and his/her background. These data suggest that changes in the weather may be more important factor for patients in asthma exacerbation
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