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Formation Stage (formation + stage)
Selected AbstractsPloidy mosaicism in well-developed nuclear transplants produced by transfer of adult somatic cell nuclei to nonenucleated eggs of medaka (Oryzias latipes)DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 9 2007Elena Kaftanovskaya Chromosomal abnormalities such as ploidy mosaicism have constituted a major obstacle to the successful nuclear transfer of adult somatic cell nuclei in lower vertebrates to date. Euploid mosaicism has been reported previously in well-developed amphibian transplants. Here, we investigated ploidy mosaicisms in well-developed transplants of adult somatic cell nuclei in medaka fish (Oryzias latipes). Donor nuclei from primary cultured cells from the adult caudal fin of a transgenic strain carrying the green fluorescent protein gene (GFP) were transferred to recipient nonenucleated eggs of a wild-type strain to produce 662 transplants. While some of the transplants developed beyond the body formation stage and several hatched, all exhibited varying degrees of abnormal morphology, limited growth and subsequent death. Twenty-one transplants, 19 embryos and two larvae, were selected for chromosomal analysis; all were well-developed 6-day-old or later embryonic stages exhibiting slight morphological abnormalities and the same pattern of GFP expression as that of the donor strain. In addition, all exhibited various levels of euploid mosaicism with haploid-diploid, haploid-triploid or haploid-diploid-triploid chromosome sets. No visible chromosomal abnormalities were observed. Thus, euploid mosaicism similar to that observed in amphibians was confirmed in well-developed nuclear transplants of fish. [source] Functional role of B,-chain N-terminal fragment in the fibrin polymerization processFEBS JOURNAL, Issue 17 2007E. V. Lugovskoy Four mAbs of the IgG1 class to the thrombin-treated N-terminal disulfide knot of fibrin, secreted by various hybridomas, have been selected. Epitopes for two mAbs, I-3C and III-10d, were situated in human fibrin fragment B,15,26, and those for two other mAbs, I-5G and I-3B, were in fragment B,26,36. Three of these mAbs, I-5G, I-3B and III-10D, as well as their Fab-fragments, decreased the maximum rate of fibrin desAA and desAABB polymerization up to 90,95% at a molar ratio of mAb (or Fab-fragment) to fibrin of 1 or 2. The fourth mAb, I-3C, did not influence the fibrin desAABB polymerization and inhibited by 50% the maximum rate of fibrin desAA polymerization. These results suggest that these mAb inhibitors block a longitudinal fibrin polymerization site. As the mAbs retard both fibrin desAABB and fibrin desAA polymerization, one can conclude that the polymerization site does not coincide with polymerization site ,B' (B,15,17). To verify this suggestion, the polymerization inhibitory activity of synthetic peptides B,SARGHRPLDKKREEA(12,26), B,LDKKREEA(19,26), B,APSLRPAPPPI(26,36), B,APSLRPAPPPISGGGYRARPA(26,46) and B,GYRARPA(40,46), which imitate the various sequences in the N-terminal region of the fibrin B,-chain, have been investigated. Peptides B,12,26 and B,26,46, but not B,40,46, B,19,26, and B,26,36, proved to be specific inhibitors of fibrin polymerization. The IC50 values for B,12,26 and B,26,46 were 2.03 × 10,4 and 2.19 × 10,4 m, respectively. Turbidity and electron microscopy data showed that peptides B,12,26 and B,26,46 inhibited the fibrin protofibril formation stage of fibrin polymerization. The conclusion was drawn that fibrin fragment B,12,46 took part in fibrin protofibril formation simultaneously with site ,A' (A,17,19) prior to removal of fibrinopeptide B. A model of the intermolecular connection between fragment B,12,46 of one fibrin desAA molecule and the D-domain of another has been constructed. [source] Cosmic-ray exposure age and heliocentric distance of the parent bodies of enstatite chondrites ALH 85119 and MAC 88136METEORITICS & PLANETARY SCIENCE, Issue 6 2006D. Nakashima These two meteorites contain solar and cosmogenic noble gases. Based on the solar and cosmogenic noble gas compositions, we calculated heliocentric distances, parent body exposure ages, and space exposure ages of the two meteorites. The parent body exposure ages are longer than 6.7 Ma for ALH 85119 and longer than 8.7 Ma for MAC 88136. The space exposure ages are shorter than 2.2 Ma for ALH 85119 and shorter than 3.9 Ma for MAC 88136. The estimated heliocentric distances are more than 1.1 AU for ALH 85119 and 1.3 AU for MAC 88136. Derived heliocentric distances indicate the locations of parent bodies in the past when constituents of the meteorites were exposed to the Sun. From the mineralogy and chemistry of E chondrites, it is believed that E chondrites formed in regions within 1.4 AU from the Sun. The heliocentric distances of the two E chondrite parent bodies are not different from the formation regions of E chondrites. This may imply that heliocentric distances of E chondrites have been relatively constant from their formation stage to the stage of exposure to the solar wind. [source] Magnaporthe grisea interactions with the model grass Brachypodium distachyon closely resemble those with rice (Oryza sativa)MOLECULAR PLANT PATHOLOGY, Issue 4 2004ANDREW P. M. ROUTLEDGE SUMMARY Germplasm of Brachypodium distachyon was inoculated with Magnaporthe grisea using either rice- (Guy11) or grass-adapted (FAG1.1.1, PA19w-06, PA31v-01) host-limited forms of the fungus, and interactions with varying degrees of susceptibility and resistance were identified. Ecotype ABR5 was resistant to each M. grisea strain whereas ABR1 was susceptible to all but P31vi-01. Mendelian segregation in ABR1 × ABR5 crosses suggested that a single dominant resistance gene conferred resistance to Guy11. Microscopic analyses revealed that the aetiology of Guy11 fungal development and disease progression in ABR1 closely resembled that of rice infections. In ABR5, Guy11 pathogenesis was first suppressed at 48 h post-inoculation, at the secondary hyphal formation stage and was coincident with cytoplasmic granulation. Resistance to strains PA31v-01 and FAG1.1.1 was associated with a localized cell death with little callose deposition. 3,3-Diaminobenzidine staining indicated the elicitation of cell death in B. distachyon was preceded by oxidative stress in the interacting epidermal cells and the underlying mesophyll cells. Northern blot hybridization using probes for barley genes (PR1, PR5 and PAL) indicated that each was more rapidly expressed in ABR5 challenged with Guy11 although the B. distachyon defence genes BD1 and BD8 were more quickly induced in ABR1. Such data show that B. distachyon is an appropriate host for functional genomic investigations into M. grisea pathology and plant responses. [source] Coalition-Targeted Duvergerian Voting: How Expectations Affect Voter Choice under Proportional RepresentationAMERICAN JOURNAL OF POLITICAL SCIENCE, Issue 2 2009Matias A. Bargsted Inspired by analyses of majoritarian systems, students of consensual polities have analyzed strategic voting due to barriers to party success, namely, district magnitude and threshold. Given the prevalence of coalition governments in proportional systems, we analyze a type of strategic voting seldom studied: how expected coalition composition affects voter choice. We identify Duvergerian behavior by voters targeted at the coalition formation stage. We contend that when voters perceive their preferred party as unlikely to participate in the coalition, they often desert it and instead support the lesser of evils among those they perceive as viable coalition partners. We demonstrate our argument using data on coalition expectations from the 2006 Israeli elections. We find an appreciable albeit differential effect of coalition expectations on voter choice. Importantly, results hold controlling for ideological and coalition preferences. Lastly, we explore a broad cross-national comparison, showing that there is less, not more, proximity voting where coalitions are prevalent. [source] cDNA cloning and expression analysis of the myosin heavy chain (MYH) gene of the mandarin fish Siniperca kneriAQUACULTURE RESEARCH, Issue 4 2009Jianshe Zhang Abstract In this study, we applied RT-PCR and cDNA cloning techniques to clone myosin heavy chain (MYH) cDNA from muscle tissues of the mandarin fish Siniperca kneri. The cDNA was determined to be of 6987 base pairs in length, encoding a peptide of 1937 amino acids (Genbank accession no. EF446616). A search of encoded protein sequences in the NCBI conserved domain database indicated the presence of all known protein domains for MYH proteins, i.e. the myosin motor domain in the N-terminal region, the DIL domain at the C-terminus, and the ATPase domain. The MYH gene and its protein were expressed predominantly in muscle tissues and weakly in cardiac tissues. Developmentally, the MYH gene was first expressed in the muscle formation stage and continued later on. Our work provided a novel mypsin heavy chain gene sequence in fish biology and the results indicate that the MYH gene and the protein it encodes are important for the growth and development of the mandarin fish, as well as its muscle characterization. [source] Tectonic Evolution of the Middle Frontal Area of the Longmen Mountain Thrust Belt, Western Sichuan Basin, ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 1 2009Wenzheng JIN Abstract: By analyzing the balanced cross sections and subsidence history of the Longmen Mountain thrust belt, China, we concluded that it had experienced five tectonic stages: (1) the formation stage (T3x) of the miniature of Longmen Mountain, early Indosinian movement, and Anxian tectonic movement created the Longmen Mountain; (2) the stable tectonic stage (J1) where weaker tectonic movement resulted in the Longmen Mountain thrust belt being slightly uplifted and slightly subsiding the foreland basin; (3) the intense tectonic stage (J2.3), namely the early Yanshan movement; (4) continuous tectonic movement (K-E), namely the late Yanshan movement and early Himalayan movement; and (5) the formation of Longmen Mountain (N-Q), namely the late Himalayan movement. During those tectonic deformation stages, the Anxian movement and Himalayan movement played important roles in the Longmen Mountain's formation. The Himalayan movement affected Longmen Mountain the most; the strata thrust intensively and were eroded severely. There are some klippes in the middle part of the Longmen Mountain thrust belt because a few nappes were pushed southeastward in later tectonic deformation. [source] Particle size effect on the film-forming process of PS/PBA composite latexesPOLYMER COMPOSITES, Issue 9 2010aziye U In this work, the effect of hard particle size and blend ratio on the film formation behavior of hard polystyrene (PS) and soft poly(n -butyl acrylate) (PBA) latex blends was studied by means of steady-state fluorescence and UV,visible techniques in conjunction with atomic force microscopy. Three different sets of latexes were synthesized: PBA latex (diameter 97 nm), pyrene (P)-labeled large PS (LgPS; diameter 900 nm), and small PS (SmPS; diameter 320 nm). Two different series of latex blends (LgPS/PBA and SmPS/PBA) were prepared with varying blend composition at room temperature separately. Films were then annealed at elevated temperatures above glass transition (Tg) temperature of PS. Fluorescence intensity (IP) from P and photon transmission intensity (Itr) were measured after each annealing step to monitor the stages of film formation. The results showed that a significant change occurred in IP and Itr at a certain critical weight fraction (Rc) of PBA. Below Rc, two distinct film formation stages, which are named as void closure and interdiffusion, were seen. However, at PBA concentrations nearer to or above Rc, no film formation can be achieved. Comparing to the LgPS/PBA, the sintering process of SmPS/PBA particles occurred at much lower temperatures. Film formation stages for R < Rc were modeled, and related activation energies were calculated. Void closure (,H) and interdiffusion (,E) activation energies for SmPS/PBA were also found smaller in comparing with LgPS/PBA series. However, ,H and ,E values were not changed much with the blend composition for both series. POLYM. COMPOS., 31:1637,1652, 2010. © 2009 Society of Plastics Engineers [source] | |||||||||||||