Probe walking : development of novel probes for DNA fingerprinting

Thesis--University of Tsukuba, D.M.S.(A), no. 786, 1990. 3. 23Offprint. Originally published in: Human genetics, v. 83, pp. 223-226, 1989Joint authors: Shogo Misawa and Shintaroh UedaIncludes supplementary treatise

An empirical analysis of employment stability, wages and unemployment rates of Japanese labor markets

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Economics, 1999.Includes bibliographical references.This paper carries out an empirical analysis of Japanese labor markets with special attention paid on the comparison with the US labor markets. Chapter 1 studies how employment stability changed by measuring historical five-year retention rates for male regular workers grouped by education level and firm size. It was found that the overall retention rates began to decrease at the current recession after the long period of stability. Owing to the law prohibiting the mandatory retirement before the age of 60, the retention rate from 50-54 years old to 55-59 years old increased. However, the retention rates decreased for younger workers. A comparative study of retention rates between Japan and the US is also carries out. Chapter 2 shows how wage structure changed from 1974 to 93 by a great increase of old and more-educated male workers. Three kinds of wage differential - by age, by education level and by firm size - were examined. It was found that the young and less educated lost the ground most compared with the more educated and old. This finding is qualitatively the same with what happened in the US. The important difference is that the change of wage structure was much smaller in Japan than in the US. A simple supply-demand framework was applied to see how the wage and employment level were determined in the labor market. It was found that demand increase took place favoring senior and more educated workers and it raised the relative wage of more educated and more experienced like in the US. Chapter 3 shows that unemployment rate has been low and stable in Japan for a long time. One reason of this is that employment fluctuation is small. The second important reason is that larger part of employment fluctuation is shared by those who move between employment and out of the labor force without experiencing unemployment compared with the US. Women, teenagers and old share larger part of employment fluctuation, and they are more prone to be discouraged workers than other demographic groups. The unemployment rate is estimated when these discouraged workers are counted as unemployed.by Keiko Ueda.Ph.D

Infrared and hard X-ray diagnostics of AGN identification from the Swift/BAT and AKARI all-sky surveys

We combine data from two all-sky surveys in order to study the connection between the infrared and hard X-ray (>10keV) properties for local active galactic nuclei (AGN). The Swift/Burst Alert Telescope all-sky survey provides an unbiased, flux-limited selection of hard X-ray detected AGN. Cross-correlating the 22-month hard X-ray survey with the AKARI all-sky survey, we studied 158 AGN detected by the AKARI instruments. We find a strong correlation for most AGN between the infrared (9, 18, and 90 micron) and hard X-ray (14-195 keV) luminosities, and quantify the correlation for various subsamples of AGN. Partial correlation analysis confirms the intrinsic correlation after removing the redshift contribution. The correlation for radio galaxies has a slope and normalization identical to that for Seyfert 1s, implying similar hard X-ray/infrared emission processes in both. In contrast, Compton-thick sources show a large deficit in the hard X-ray band, because high gas column densities diminish even their hard X-ray luminosities. We propose two photometric diagnostics for source classification: one is an X-ray luminosity vs. infrared color diagram, in which type 1 radio-loud AGN are well isolated from the others in the sample. The other uses the X-ray vs. infrared color as a useful redshift-independent indicator for identifying Compton-thick AGN. Importantly, Compton-thick AGN and starburst galaxies in composite systems can also be differentiated in this plane based upon their hard X-ray fluxes and dust temperatures. This diagram may be useful as a new indicator to classify objects in new and upcoming surveys such as WISE and NuSTAR.Comment: 17 pages, 5 figures, 5 tables. Accepted for publication in the Astrophysical Journa

Iron promotes oxidative cell death caused by bisretinoids of retina

Intracellular Fe plays a key role in redox active energy and electron transfer. We sought to understand how Fe levels impact the retina, given that retinal pigment epithelial (RPE) cells are also challenged by accumulations of vitamin A aldehyde adducts (bisretinoid lipofuscin) that photogenerate reactive oxygen species and photodecompose into damaging aldehyde- and dicarbonyl-bearing species. In mice treated with the Fe chelator deferiprone (DFP), intracellular Fe levels, as reflected in transferrin receptor mRNA expression, were reduced. DFP-treated albino Abca4−/− and agouti wild-type mice exhibited elevated bisretinoid levels as measured by high-performance liquid chromatography or noninvasively by quantitative fundus autofluorescence. Thinning of the outer nuclear layer, a parameter indicative of the loss of photoreceptor cell viability, was also reduced in DFP-treated albino Abca4−/−. In contrast to the effects of the Fe chelator, mice burdened with increased intracellular Fe in RPE due to deficiency in the Fe export proteins hephaestin and ceruloplasmin, presented with reduced bisretinoid levels. These findings indicate that intracellular Fe promotes bisretinoid oxidation and degradation. This interpretation was supported by experiments showing that DFP decreased the oxidative/degradation of the bisretinoid A2E in the presence of light and reduced cell death in cell-based experiments. Moreover, light-independent oxidation and degradation of A2E by Fenton chemistry products were evidenced by the consumption of A2E, release of dicarbonyls, and generation of oxidized A2E species in cell-free assays