Study on Dynamical process in Boolean Network.

This thesis began with a question about how the human brain works and then two type of Boolean Networks , 1-D Cellular Automata and Associate Memory Model are chosen to explore this question. In the first part of this thesis the computability of 1-D Cellular Automata is studied by inventing a simple model, 3 colored balls model and several logical gates are implemented in its space. Although this model is so simple, by implementing three important logical gates, NOT , AND and OR , 3 colored balls model is proved to be computational universal. Since a common property annihilation is seen in each gate for having computability, the property is also used to prove the computational universality of Elemental Cellular Automata. ln the other part of thesis the probability of errors in the recurrent associate memory model is studied. To study dynamics of the recurrent model, I use the same MDS code as an input and an output and found the probability distribution of the number of extra ones that may appear through associate map. By the probability distribution we found that the number of error is going to decrease when the larger MOS code is used and also by comparing to binomial distribution both results are close and when we choose the larger MDS code the difference of both is getting closer

FeII/MgII Emission Line Ratios of QSOs. II. z>6 Objects

Near-infrared spectra of four QSOs located at $z>6$ are obtained with the OH-airglow suppressor mounted on the Subaru telescope. The FeII/MgII emission-line ratios of these QSOs are examined by the same fitting algorithm as in our previous study of $z<5.3$ QSOs. The fitting results show that two out of the four $z>6$ QSOs have significant FeII emission in their rest-UV spectra, while the other two have almost no FeII features. We also applied our fitting algorithm to more than 10,000 SDSS QSOs and found two trends in the distribution of FeII/MgII against redshift: (1) the upper envelope of the FeII/MgII distribution at $z>3$ shows a probable declination toward high redshift, and (2) the median distribution settles into lower ratios at $z\sim 1.5$ with small scatter compared to the other redshift. We discuss an Fe/Mg abundance evolution of QSOs with a substantial contribution from the diverse nature of the broad-line regions in high-redshift QSOs.Comment: 12 pages, 2 figures. Accepted for publication in ApJ (10 October 2004, v614

Proliferation of adult rat hepatocytes by hepatocyte growth factor is potentiated by both phenylephrine and metaproterenol

ABSTRACT We investigated whether or not beta and alpha adrenergic agonists could affect proliferation of adult rat hepatocytes induced by hepatocyte growth factor (HGF) during the early and late phases of primary culture. Adult rat hepatocytes underwent significant DNA synthesis after culture with 5 ng/ml HGF for 3 h at a low cell density (3.3 ϫ 10 4 cells/cm 2 ). Under these culture conditions, the number of nuclei increased significantly during a subsequent 4-h culture period. Hepatocyte DNA synthesis and proliferation induced by 5 ng/ml HGF was reduced at high cell densities near confluence. A beta adrenergic agonist, metaproterenol (10 Ϫ7 M), and dibutyryl cAMP significantly potentiated hepatocyte DNA synthesis and proliferation at a concentration as low as 10 Ϫ7 M when cultured in combination with 5 ng/ml HGF. Similarly, an alpha-1 adrenergic agonist, phenylephrine (10 Ϫ6 -10 Ϫ4 M) markedly potentiated HGF-induced hepatocyte DNA synthesis and proliferation. The phenylephrine effect was mimicked by a phorbol ester (10 Ϫ6 M), but not by ionomycin (10 Ϫ6 M). The mitogenic effects of HGF were almost completely blocked by simultaneous treatment of hepatocytes with genistein (5 ϫ 10 Ϫ6 M), U-73122 (10 Ϫ6 M), wortmannin (10 Ϫ7 M), sphingosine (3 ϫ 10 Ϫ6 M) and rapamycin (10 ng/ml). These results demonstrate that HGF can rapidly induce proliferation of adult rat hepatocytes in primary culture. However, this effect is dependent on the initial plating density. The comitogenic effects of metaproterenol and phenylephrine may involve both protein kinase A and protein kinase C activation, respectively. The results also suggest that following stimulation with HGF, activation of tyrosine kinase, phosphatidylinositol 3-kinase, phospholipase C and p70 ribosomal protein S6 kinase is essential for hepatocyte proliferation

Design and performance of a F/#-conversion microlens for Prime Focus Spectrograph at Subaru Telescope

The PFS is a multi-object spectrograph fed by 2394 fibers at the prime focus of Subaru telescope. Since the F/# at the prime focus is too fast for the spectrograph, we designed a small concave-plano negative lens to be attached to the tip of each fiber that converts the telescope beam (F/2.2) to F/2.8. We optimized the lens to maximize the number of rays that can be confined inside F/2.8 while maintaining a 1.28 magnification. The microlenses are manufactured by glass molding, and an ultra-broadband AR coating (<1.5% for lambda=0.38-1.26 um) will be applied to the front surface.Comment: 7 pages, 8 figures, SPIE201