Studies on the relation between heme and nucleic acid syntheses in erythroid cell. 3. Nucleolus of erythroblast, changes in relation with cell specialization

The disappearance of nucleolus has been traced in the rat erythroid cells in relation with the cell specialization under varying conditions, i. e. in anemia with or without treatment by bromouracil and aminopterin. To make the findings more reliable the observations have been made on tissue section as well as on the smeared samples as the nucleolus becomes often indistinct in smeared cell. The results indicate that under anemic condition nucleolus is lost by the late basoplilic stage. Treatment with bromouracil retained the nucleoli and cytoplasmic basophilicity till later stage of cell specialization suggesting some similar mechanism of RNA disintegration both in nucleolus and cytoplasm.</p

Studies on the relation between heme and nucleic acid syntheses in erythroid cell. II. Nucleic acid synthesis in erythroblast of anemic rat treated with aminopterin and bromouracil

With the bone marrow of anemic rats, which had received the repeated injections of phenylhydrazine once a day for three to four days, the effects of aminopterin and bromouracil on the nucleic acid metabolism of erythroblasts were observed in vivo experiment. The injection of aminopterin suppressed DNA synthesis with the lowered labeling index as observed by the incorporation of &#179;H-thymidine into DNA in vitro. But the grain count per cell showed the level similar to that of anemic control. RNA synthesis was not interfered by AP injections. These results indicate that AP mainly suppresses the thymidilate kinase. Bromouracil showed no such effect even on the administration of a large dose. On the basis of the data obtained from the experiment by using AP, a discussion was made on the correlation between DNA synthesis, nuclear function and the cell specialization.</p

The Flying Geese Paradigm: A critical study of its application to East Asian regional development

It is often claimed that what is popularly known as the "flying geese paradigm" of dynamic comparative advantage has accurately depicted the East Asian catching-up process. This paper presents a critical study of the paradigm, as well as its application to the current situation in East Asia economic hierarchy. The paper first presents the various versions of the paradigm, and discusses similarities and differences among them. It then evaluates the application of the paradigm to the East Asian regional development context by identifying major theoretical, conceptual and empirical problems that come with it. It is the author's hope that the arguments presented in this paper will contribute to the further enrichment of future discussions on the East Asian development experience.Flying geese paradigm; East Asia; Catching-up process; product cycle;

THE FLYING GEESE PARADIGM: A CRITICAL STUDY OF ITS APPLICATION TO EAST ASIAN REGIONAL DEVELOPMENT

It is often claimed that what is popularly known as the “flying geese paradigm” of dynamic comparative advantage has accurately depicted the East Asian catching-up process. This paper presents a critical study of the paradigm, as well as its application to the current situation in East Asian economic hierarchy. The paper first presents the various versions of the paradigm, and discusses similarities and differences among them. It then evaluates the application of the paradigm to the East Asian regional development context by identifying major theoretical, conceptual and empirical problems that come with it. It is the author’s hope that the arguments presented in this paper will contribute to the further enrichment of future discussions on the East Asian development experience.

Evidence for Infalling Gas of Low Angular Momentum towards the L1551 NE Keplerian Circumbinary Disk

We report follow-up observations of the Class I binary protostellar system L1551 NE in the C18O (3--2) line with the SMA in its compact and subcompact configurations. Our previous observations at a higher angular resolution in the extended configuration revealed a circumbinary disk exhibiting Keplerian motion. The combined data having more extensive spatial coverage (~140 - 2000 AU) verify the presence of a Keplerian circumbinary disk, and reveals for the first time a distinct low-velocity (~< +-0.5 km s-1 from the systemic velocity) component that displays a velocity gradient along the minor axis of the circumbinary disk. Our simple model that reproduces the main features seen in the Position-Velocity diagrams comprises a circumbinary disk exhibiting Keplerian motion out to a radius of ~300 AU, beyond which the gas exhibits pure infall at a constant velocity of ~0.6 km s-1. The latter is significantly smaller than the expected free-fall velocity of ~2.2 km s-1 onto the L1551 NE protostellar mass of ~0.8 Msun at ~300 AU, suggesting that the infalling gas is decelerated as it moves into regions of high gas pressure in the circumbinary disk. The discontinuity in angular momenta between the outer infalling gas and inner Keplerian circumbinary disk implies an abrupt transition in the effectiveness at which magnetic braking is able to transfer angular momentum outwards, a result perhaps of the different plasma beta and ionization fractions between the outer and inner regions of the circumbinary disk.Comment: 23 pages, 5 figure

Studies on the relation between heme and nucleic acid syntheses in erythroid cell. I. Effects of aminopterin and bromouracil on hemopoiesis and hemoglobin synthesis in anemic rat

For the purpose to see how the suppression of the nucleic acid synthesis disturbs the cell specialization process the author observed the erythroid cell specialization in anemic rats by treating them with aminopterin (AP) and 5-bromouracil (BU). The observations indicate that the AP injection inhibits the mitosis of erythroblast with the acceleration of hemoglobin synthesis and the denucleation. The bromouracil administration scarcely suppressed the mitosis and the appearance of acidophilicity of erythroblast was retarded. Data indicate that the inhibition of mitosis accelerates the specialization or somatic protein synthesis of erythroblast. The acting mechanisms of the medicaments were discussed from the characteristics of these agents as the analogue of the substances related to DNA metabolism.</p

Duration Curves of Logarithmic Normal Distribution Type and Their Applications

A statistical study was made on duration curves mainly of hydrological data, such as rainfalls and river discharges, which are the basis of waterworks planning. New proposals were made covering various fields such as application and reliability as well as fundamental theory and method of estimation, and many theoretical and practical results were obtained