92 research outputs found
Structural characteristics of the redox-sensing coiled coil in the voltage-gated H^+ channel
This research was originally published in Journal of Biological Chemistry. Yuichiro Fujiwara, Kohei Takeshita, Atsushi Nakagawa and Yasushi Okamura. Structural characteristics of the redox-sensing coiled coil in the voltage-gated H^+ channel. Journal of Biological Chemistry. 2013; 288, 17968-17975. © the American Society for Biochemistry and Molecular Biology
Pareto index induced from the scale of companies
Employing profits data of Japanese companies in 2002 and 2003, we confirm
that Pareto's law and the Pareto index are derived from the law of detailed
balance and Gibrat's law. The last two laws are observed beyond the region
where Pareto's law holds. By classifying companies into job categories, we find
that companies in a small scale job category have more possibilities of growing
than those in a large scale job category. This kinematically explains that the
Pareto index for the companies in the small scale job class is larger than that
for the companies in the large scale job class.Comment: 14 pages, 11 figure
Effective gene collection from the metatranscriptome of marine microorganisms
<p>Abstract</p> <p>Background</p> <p>Metagenomic studies, accelerated by the evolution of sequencing technologies and the rapid development of genomic analysis methods, can reveal genetic diversity and biodiversity in various samples including those of uncultured or unknown species. This approach, however, cannot be used to identify active functional genes under actual environmental conditions. Metatranscriptomics, which is similar in approach to metagenomics except that it utilizes RNA samples, is a powerful tool for the transcriptomic study of environmental samples. Unlike metagenomic studies, metatranscriptomic studies have not been popular to date due to problems with reliability, repeatability, redundancy and cost performance. Here, we propose a normalized metatranscriptomic method that is suitable for the collection of genes from samples as a platform for comparative transcriptomics.</p> <p>Results</p> <p>We constructed two libraries, one non-normalized and the other normalized library, from samples of marine microorganisms taken during daylight hours from Hiroshima bay in Japan. We sequenced 0.6M reads for each sample on a Roche GS FLX, and obtained 0.2M genes after quality control and assembly. A comparison of the two libraries showed that the number of unique genes was larger in the normalized library than in the non-normalized library. Functional analysis of genes revealed that a small number of gene groups, ribosomal RNA genes and chloroplast genes, were dominant in both libraries. Taxonomic distribution analysis of the libraries suggests that Stramenopiles form a major taxon that includes diatoms. The normalization technique thus increases unique genes, functional categories of genes, and taxonomic richness.</p> <p>Conclusions</p> <p>Normalization of the marine metatranscriptome could be useful in increasing the number of genes collected, and in reducing redundancies among highly expressed genes. Gene collection through the normalization method was effective in providing a foundation for comparative transcriptomic analysis.</p
The uniqueness of company size distribution function from tent-shaped growth rate distribution
We report the proof that the extension of Gibrat's law in the middle scale
region is unique and the probability distribution function (pdf) is also
uniquely derived from the extended Gibrat's law and the law of detailed
balance. In the proof, two approximations are employed. The pdf of growth rate
is described as tent-shaped exponential functions and the value of the origin
of the growth rate distribution is constant. These approximations are confirmed
in profits data of Japanese companies 2003 and 2004. The resultant profits pdf
fits with the empirical data with high accuracy. This guarantees the validity
of the approximations.Comment: 6 pages, 5 figure
Crystal structure of lipoate-protein ligase A from Escherichia coli : Determination of the lipoic acid-binding site
This research was originally published in Journal of Biological Chemistry. Kazuko Fujiwara, Sachiko Toma, Kazuko Okamura-Ikeda, Yutaro Motokawa, Atsushi Nakagawa and Hisaaki Taniguchi. Crystal structure of lipoate-protein ligase A from Escherichia coli : Determination of the lipoic acid-binding site. Journal of Biological Chemistry. 2005; 280, 33645-33651. © the American Society for Biochemistry and Molecular Biology
Pareto law and Pareto index in the income distribution of Japanese companies
In order to study the phenomenon in detail that income distribution follows
Pareto law, we analyze the database of high income companies in Japan. We find
a quantitative relation between the average capital of the companies and the
Pareto index. The larger the average capital becomes, the smaller the Pareto
index becomes. From this relation, we can possibly explain that the Pareto
index of company income distribution hardly changes, while the Pareto index of
personal income distribution changes sharply, from a viewpoint of capital (or
means). We also find a quantitative relation between the lower bound of capital
and the typical scale at which Pareto law breaks. The larger the lower bound of
capital becomes, the larger the typical scale becomes. From this result, the
reason there is a (no) typical scale at which Pareto law breaks in the income
distribution can be understood through (no) constraint, such as the lower bound
of capital or means of companies, in the financial system.Comment: 12 pages, 8 figure
Derivation of the distribution from extended Gibrat's law
Employing profits data of Japanese companies in 2002 and 2003, we identify
the non-Gibrat's law which holds in the middle profits region. From the law of
detailed balance in all regions, Gibrat's law in the high region and the
non-Gibrat's law in the middle region, we kinematically derive the profits
distribution function in the high and middle range uniformly. The distribution
function accurately fits with empirical data without any fitting parameter.Comment: 13 pages, 8 figure
Structural basis for the membrane association of ankyrinG via palmitoylation
Fujiwara, Y., Kondo, H., Shirota, M. et al. Structural basis for the membrane association of ankyrinG via palmitoylation. Sci Rep 6, 23981 (2016) doi:10.1038/srep2398
Shape of Growth Rate Distribution Determines the Type of Non-Gibrat's Property
In this study, the authors examine exhaustive business data on Japanese
firms, which cover nearly all companies in the mid- and large-scale ranges in
terms of firm size, to reach several key findings on profits/sales distribution
and business growth trends. First, detailed balance is observed not only in
profits data but also in sales data. Furthermore, the growth-rate distribution
of sales has wider tails than the linear growth-rate distribution of profits in
log-log scale. On the one hand, in the mid-scale range of profits, the
probability of positive growth decreases and the probability of negative growth
increases symmetrically as the initial value increases. This is called
Non-Gibrat's First Property. On the other hand, in the mid-scale range of
sales, the probability of positive growth decreases as the initial value
increases, while the probability of negative growth hardly changes. This is
called Non-Gibrat's Second Property. Under detailed balance, Non-Gibrat's First
and Second Properties are analytically derived from the linear and quadratic
growth-rate distributions in log-log scale, respectively. In both cases, the
log-normal distribution is inferred from Non-Gibrat's Properties and detailed
balance. These analytic results are verified by empirical data. Consequently,
this clarifies the notion that the difference in shapes between growth-rate
distributions of sales and profits is closely related to the difference between
the two Non-Gibrat's Properties in the mid-scale range.Comment: 22 pages, 17 figure
A functional genomics tool for the Pacific bluefin tuna: Development of a 44K oligonucleotide microarray from whole-genome sequencing data for global transcriptome analysis
AbstractBluefin tunas are one of the most important fishery resources worldwide. Because of high market values, bluefin tuna farming has been rapidly growing during recent years. At present, the most common form of the tuna farming is based on the stocking of wild-caught fish. Therefore, concerns have been raised about the negative impact of the tuna farming on wild stocks. Recently, the Pacific bluefin tuna (PBT), Thunnus orientalis, has succeeded in completing the reproduction cycle under aquaculture conditions, but production bottlenecks remain to be solved because of very little biological information on bluefin tunas. Functional genomics approaches promise to rapidly increase our knowledge on biological processes in the bluefin tuna. Here, we describe the development of the first 44K PBT oligonucleotide microarray (oligo-array), based on whole-genome shotgun (WGS) sequencing and large-scale expressed sequence tags (ESTs) data. In addition, we also introduce an initial 44K PBT oligo-array experiment using in vitro grown peripheral blood leukocytes (PBLs) stimulated with immunostimulants such as lipopolysaccharide (LPS: a cell wall component of Gram-negative bacteria) or polyinosinic:polycytidylic acid (poly I:C: a synthetic mimic of viral infection). This pilot 44K PBT oligo-array analysis successfully addressed distinct immune processes between LPS- and poly I:C- stimulated PBLs. Thus, we expect that this oligo-array will provide an excellent opportunity to analyze global gene expression profiles for a better understanding of diseases and stress, as well as for reproduction, development and influence of nutrition on tuna aquaculture production
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