Fertilization between rotifer Brachionus plicatilis strains at different temperatures     

Tomonari  KOTANI  Atsushi  HAGIWARA 《Fisheries Science》2003,69(5):1078-1080

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Tissue-dependent somaclonal mutation frequencies and spectra enhanced by ion beam irradiation in chrysanthemum     

Masachika Okamura  Yoshihiro Hase  Yoshiya Furusawa  Atsushi Tanaka 《Euphytica》2015,202(3):333-343

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Effects of Organo-mineral Complexes on Flocculation, Settlement and Vertical Distribution of Bioelements in Soil Suspensions     

Atsushi Suetsugu  Takashi Sato  Yoshihiro Kaneta  Atsushi Sato 《Soil Science and Plant Nutrition》2005,51(3):323-331

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Structural unit of xylans from sugi (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) and hinoki (<Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis>)     

Takashi Yamasaki  Ayumi Enomoto  Atsushi Kato  Tadashi Ishii  Kazumasa Shimizu 《Journal of Wood Science》2011,57(1):76-84

Arabinoglucuronoxylans (AGXs) isolated from the holocellulose of sugi (Cryptomeria japonica) and hinoki (Chamaecyparis obtusa) contained one 4-O-methyl-d-glucopyranosyluronic acid (4-O-Me-d-GlcAp) residue per 6.2 d-xylopyranose (d-Xylp) residues and one 4-O-Me-d-GlcAp residue per 3.8 d-Xylp residues. These AGXs were subjected to partial acid hydrolysis. Analyses by size exclusion chromatography and electrospray-ionization mass spectroscopy of the neutral sugar fractions in the hydrolysates showed the presence of xylooligosaccharides having a degree of polymerization of 2-8 in addition to d-Xyl, suggesting that the AGXs from sugi and hinoki contained unsubstituted chains consisting of at least eight d-Xyl residues. The acidic sugars in the hydrolysates were separated into two series of aldouronic acids composed of 4-O-Me-d-GlcAp and d-Xylp by ion-exchange chromatography. The first series included aldouronic acids from aldobiouronic acid (4-O-Me-d-GlcAp-Xyl) to aldopentaouronic acids (4-O-Me-d-GlcAp-Xyl₄). The second series were aldouronic acids composed of two 4-O-Me-d-GlcAp residues and 2-4 d-Xyl residues. In these acidic sugars, the uronic acid side chains were located on two contiguous d-Xyl residues. These facts indicated that AGXs from sugi and hinoki had a structural unit containing two 4-O-Me-d-GlcAp residues on two contiguous d-Xyl residues as well as AGXs from spruce and larch.  相似文献   

Why invest in minor projects in sub-Saharan Africa? An exploration of the scale economy and diseconomy of irrigation projects     

Hitoshi Fujiie  Atsushi Maruyama  Masako Fujiie  Michiko Takagaki  Douglas J. Merrey  Masao Kikuchi 《Irrigation and Drainage Systems》2011,25(1):39-60

It is well-known that major irrigation projects have a strong scale economy, handicapping irrigation development in sub-Saharan Africa (SSA) because of the difficulty in formulating large-scale projects. Using project-level investment cost and performance data of major and minor irrigation projects, this paper examines the causes of the economy of scale phenomenon. We find that strong scale economy exists not only for major but also for minor projects, i.e., small- and micro-scale, projects. This is largely because of the existence of indivisible overhead costs such as high-opportunity-cost human resources for planning, designing and engineering management and supervision. We also find that large differences between major and minor projects in the absolute level of overhead as well as construction costs creates a strong scale diseconomy and results in better performance of minor projects. The advantage of minor projects holds even when their higher risk associated with the water source is taken into consideration. We argue that there is an urgent need to promote irrigation development in SSA through developing minor projects, and to reduce the heavy burden of overhead costs by developing the capacity of human resources at the national, local and farmer levels in the fields of irrigation engineering, irrigation agronomy, institutional development, and micro water management technologies.  相似文献   

The Physcomitrella genome reveals evolutionary insights into the conquest of land by plants     

Rensing SA  Lang D  Zimmer AD  Terry A  Salamov A  Shapiro H  Nishiyama T  Perroud PF  Lindquist EA  Kamisugi Y  Tanahashi T  Sakakibara K  Fujita T  Oishi K  Shin-I T  Kuroki Y  Toyoda A  Suzuki Y  Hashimoto S  Yamaguchi K  Sugano S  Kohara Y  Fujiyama A  Anterola A  Aoki S  Ashton N  Barbazuk WB  Barker E  Bennetzen JL  Blankenship R  Cho SH  Dutcher SK  Estelle M  Fawcett JA  Gundlach H  Hanada K  Heyl A  Hicks KA  Hughes J  Lohr M  Mayer K  Melkozernov A  Murata T  Nelson DR  Pils B  Prigge M  Reiss B  Renner T  Rombauts S  Rushton PJ 《Science (New York, N.Y.)》2008,319(5859):64-69

We report the draft genome sequence of the model moss Physcomitrella patens and compare its features with those of flowering plants, from which it is separated by more than 400 million years, and unicellular aquatic algae. This comparison reveals genomic changes concomitant with the evolutionary movement to land, including a general increase in gene family complexity; loss of genes associated with aquatic environments (e.g., flagellar arms); acquisition of genes for tolerating terrestrial stresses (e.g., variation in temperature and water availability); and the development of the auxin and abscisic acid signaling pathways for coordinating multicellular growth and dehydration response. The Physcomitrella genome provides a resource for phylogenetic inferences about gene function and for experimental analysis of plant processes through this plant's unique facility for reverse genetics.  相似文献   

Role for piRNAs and noncoding RNA in de novo DNA methylation of the imprinted mouse Rasgrf1 locus     

Watanabe T  Tomizawa S  Mitsuya K  Totoki Y  Yamamoto Y  Kuramochi-Miyagawa S  Iida N  Hoki Y  Murphy PJ  Toyoda A  Gotoh K  Hiura H  Arima T  Fujiyama A  Sado T  Shibata T  Nakano T  Lin H  Ichiyanagi K  Soloway PD  Sasaki H 《Science (New York, N.Y.)》2011,332(6031):848-852

Genomic imprinting causes parental origin-specific monoallelic gene expression through differential DNA methylation established in the parental germ line. However, the mechanisms underlying how specific sequences are selectively methylated are not fully understood. We have found that the components of the PIWI-interacting RNA (piRNA) pathway are required for de novo methylation of the differentially methylated region (DMR) of the imprinted mouse Rasgrf1 locus, but not other paternally imprinted loci. A retrotransposon sequence within a noncoding RNA spanning the DMR was targeted by piRNAs generated from a different locus. A direct repeat in the DMR, which is required for the methylation and imprinting of Rasgrf1, served as a promoter for this RNA. We propose a model in which piRNAs and a target RNA direct the sequence-specific methylation of Rasgrf1.  相似文献   

Regulated fast nucleocytoplasmic shuttling observed by reversible protein highlighting     

Ando R  Mizuno H  Miyawaki A 《Science (New York, N.Y.)》2004,306(5700):1370-1373

The observation of the regulation of fast protein dynamics in a cellular context requires the development of reliable technologies. Here, a signal regulation cascade reliant on the stimulus-dependent acceleration of the bidirectional flow of mitogen-activated protein kinase (extracellular signal-regulated kinase) across the nuclear envelope was visualized by reversible protein highlighting. Light-induced conversion between the bright and dark states of a monomeric fluorescent protein engineered from a novel coral protein was employed. Because of its photochromic properties, the protein could be highlighted, erased, and highlighted again in a nondestructive manner, allowing direct observation of regulated fast nucleocytoplasmic shuttling of key signaling molecules.  相似文献   

Strength properties of glued laminated timber made from edge-glued laminae II: bending,tensile, and compressive strength of glued laminated timber     

Yasushi?HiramatsuEmail author  Kiyohiko?Fujimoto  Atsushi?Miyatake  Kenta?Shindo  Hirofumi?Nagao  Hideo?Kato  Hirofumi?Ido 《Journal of Wood Science》2011,57(1):66-70

The purpose of this study was to investigate the strength properties of glued laminated timber composed of edge-glued laminae and to investigate the influence of edge gluing on the strength properties. Glued laminated timber composed of multiple-grade laminae (symmetrical composition, strength grade E95-F270, 10 laminations) was produced from karamatsu (Larix kaempferi) edge-glued laminae according to the Japanese Agricultural Standard. The bending, tensile, and compressive strengths of the glued laminated timber were measured. The average bending, tensile, and compressive strengths were 33.4, 24.5, and 35.9 MPa, respectively, and these values are almost equal to those of glued laminated timber composed of karamatsu single-piece laminae. It was determined that finger-joints and knots in the edge-glued laminae played a significant role in the failure of specimens. However, the use of glued edge-joints did not appear to affect the failure of specimens.  相似文献   

DNA methylation analysis on satellite I region in blastocysts obtained from somatic cell cloned cattle     

Ken‐ichi YAMANAKA  Masahiro KANEDA  Yasushi INABA  Koji SAITO  Kaiyu KUBOTA  Miki SAKATANI  Satoshi SUGIMURA  Kei IMAI  Shinya WATANABE  Masashi TAKAHASHI 《Animal Science Journal》2011,82(4):523-530

Many observations have been made on cloned embryos and on adult clones by somatic cell nuclear transfer (SCNT), but it is still unclear whether the progeny of cloned animals is presenting normal epigenetic status. Here, in order to accumulate the information for evaluating the normality of cloned cattle, we analyzed the DNA methylation status on satellite I region in blastocysts obtained from cloned cattle. Embryos were produced by artificial insemination (AI) to non‐cloned or cloned dams using semen from non‐cloned or cloned sires. After 7 days of AI, embryos at blastocyst stage were collected by uterine flushing. The DNA methylation levels in embryos obtained by using semen and/or oocytes from cloned cattle were similar to those in in vivo embryos from non‐cloned cattle. In contrast, the DNA methylation levels in SCNT embryos were significantly higher (P < 0.01) than those in in vivo embryos from non‐cloned and cloned cattle, approximately similar to those in somatic cells used as donor cells. Thus, this study provides useful information that epigenetic status may be normal in the progeny of cloned cattle, suggesting the normality of germline cells in cloned cattle.  相似文献