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Sample records for cdnas exhibits homology

  1. Three cDNAs encoding vitellogenin homologs from Antarctic copepod, Tigriopus kingsejongensis: Cloning and transcriptional analysis in different maturation stages, temperatures, and putative reproductive hormones.

    Science.gov (United States)

    Lee, Soo Rin; Lee, Ji-Hyun; Kim, Ah Ran; Kim, Sanghee; Park, Hyun; Baek, Hea Ja; Kim, Hyun-Woo

    2016-02-01

    Three full-length cDNAs encoding lipoprotein homologs were identified in Tigriopus kingsejongensis, a newly identified copepod from Antarctica. Structural and transcriptional analyses revealed homology with two vitellogenin-like proteins, Tik-Vg1 and Tik-Vg2, which were 1855 and 1795 amino acids in length, respectively, along with a third protein, Tik-MEP, which produced a 1517-residue protein with similarity to a melanin engaging protein (MEP) in insects Phylogenetic analysis showed that Vgs in Maxillopods including two Tik-Vgs belong to the arthropod vitellogenin-like clade, which includes clottable proteins (CPs) in decapod crustaceans and vitellogenins in insects. Tik-MEP clustered together with insect MEPs, which appear to have evolved before the apoB-like and arthropod Vg-like clades. Interestingly, no genes orthologous to those found in the apoB clade were identified in Maxillopoda, suggesting that functions of large lipid transfer proteins (LLTPs) in reproduction and lipid metabolism may be different from those in insect and decapod crustaceans. As suggested by phylogenetic analyses, the two Tik-Vgs belonging to the arthropod Vg-like clade appear to play major roles in oocyte maturation, while Vgs belonging to the apoB clade function primarily in the reproduction of decapod crustaceans. Transcriptional analysis of Tik-Vg expression revealed a 24-fold increase in mature and ovigerous females compared with immature female, whereas expression of Tik-MEP remained low through all reproductive stages. Acute temperature changes did not affect the transcription of Tik-Vg genes, whereas Tik-MEP appeared to be affected by temperature change. Among the three hormones thought to be involved in molting and reproduction in arthropods, only farnesoic acid (FA) induced transcription of the two Tik-Vg genes. Regardless of developmental stage and hormone treatment, Tik-Vg1 and Tik-Vg2 exhibited a strong positive correlation in expression, suggesting that expression of these

  2. Homologous Recombination Defective Arabidopsis Mutants Exhibit Enhanced Sensitivity to Abscisic Acid.

    Directory of Open Access Journals (Sweden)

    Sujit Roy

    Full Text Available Abscisic acid (ABA acts as an important plant hormone in regulating various aspects of plant growth and developmental processes particularly under abiotic stress conditions. An increased ABA level in plant cells inhibits DNA replication and cell division, causing plant growth retardation. In this study, we have investigated the effects of ABA on the growth responses of some major loss-of-function mutants of DNA double-stand break (DSB repair genes in Arabidopsis during seed germination and early stages of seedling growth for understanding the role of ABA in the induction of genome instability in plants. A comparative analysis of ABA sensitivity of wild-type Arabidopsis and the knockout mutant lines related to DSB sensors, including atatm, atatr, the non-homologous end joining (NHEJ pathway genes, and mutants related to homologous recombination (HR pathway genes showed relatively enhanced sensitivity of atatr and HR-related mutants to ABA treatment. The expression levels of HR-related genes were increased in wild-type Arabidopsis (Col-0 during seed germination and early stages of seedling growth. Immunoblotting experiments detected phosphorylation of histone H2AX in wild-type (Col-0 and DSB repair gene mutants after ABA treatment, indicating the activation of DNA damage response due to ABA treatment. Analyses of DSB repair kinetics using comet assay under neutral condition have revealed comparatively slower DSB repair activity in HR mutants. Overall, our results have provided comprehensive information on the possible effect of ABA on DNA repair machinery in plants and also indicated potential functional involvement of HR pathway in repairing ABA induced DNA damage in Arabidopsis.

  3. Plants experiencing chronic internal exposure to ionizing radiation exhibit higher frequency of homologous recombination than acutely irradiated plants

    Energy Technology Data Exchange (ETDEWEB)

    Kovalchuk, O.; Kovalchuk, I.; Hohn, B. [Friedrich Miescher Institute, P.O. Box 2543, CH-4002 Basel (Switzerland); Arkhipov, A. [Chernobyl Scientific and Technical Center of International Research, Shkolnaya Str. 6, 255620 Chernobyl (Ukraine); Barylyak, I.; Karachov, I. [Ukrainian Scientific Genetics Center, Popudrenko Str. 50, 253660 Kiev (Ukraine); Titov, V. [Ivano-Frankivsk State Medical Academy, Galitska Str.2, 284000 Ivano-Frankivsk (Ukraine)

    2000-04-03

    Ionizing radiation (IR) is a known mutagen responsible for causing DNA strand breaks in all living organisms. Strand breaks thus created can be repaired by different mechanisms, including homologous recombination (HR), one of the key mechanisms maintaining genome stability [A. Britt, DNA damage and repair in plants, Annu. Rev. Plant. Phys. Plant Mol. Biol., 45 (1996) 75-100; H. Puchta, B. Hohn, From centiMorgans to basepairs: homologous recombination in plants, Trends Plant Sci., 1 (1996) 340-348.]. Acute or chronic exposure to IR may have different influences on the genome integrity. Although in a radioactively contaminated environment plants are mostly exposed to chronic pollution, evaluation of both kinds of influences is important. Estimation of the frequency of HR in the exposed plants may serve as an indication of genome stability. We used previously generated Arabidopsis thaliana and Nicotiana tabacum plants, transgenic for non-active versions of the {beta}-glucoronidase gene (uidA) [P. Swoboda, S. Gal, B. Hohn, H. Puchta, Intrachromosomal homologous recombination in whole plants, EMBO J., 13 (1994) 484-489; H. Puchta, P. Swoboda, B. Hohn, Induction of homologous DNA recombination in whole plants, Plant, 7 (1995) 203-210.] serving as a recombination substrate, to study the influence of acute and chronic exposure to IR on the level of HR as example of genome stability in plants. Exposure of seeds and seedlings to 0.1 to 10.0 Gy 60Co resulted in increased HR frequency, although the effect was more pronounced in seedlings. For the study of the influence of chronic exposure to IR, plants were grown on two chemically different types of soils, each artificially contaminated with equal amounts of 137Cs. We observed a strong and significant correlation between the frequency of HR in plants, the radioactivity of the soil samples and the doses of radiation absorbed by plants (in all cases r0.9, n=6, P<0.05). In addition, we noted that plants grown in soils with

  4. Exhibition

    CERN Document Server

    Staff Association

    2017-01-01

    A Look of Hope Islam Mahmoud Sweity From 19 to 30 June 2017 CERN Meyrin, Main Building Islam Mahmoud Sweity Islam Mahmoud Sweity was born in 1997 at Beit Awwa, Palestine. She is currently following a course to get an Art diploma of Painting at the college of Fine Arts at An-Najah National University under the supervision of Esmat Al As'aad. Her portraits, landscapes and still life paintings are full of life and shining colours. Charged of emotional empathy they catch the attention of the viewer and are reminding us that life is beautiful and worth living in spite of all difficulties we have to go through. She participated in many exhibitions and has exposed her drawings in 2015 at CERN and in France in the framework of the exhibition "The Origin“, and in 2017 in the Former Yugoslav Republic of Macedonia, Palestina and Jordan. In this exhibition the oil paintings made in the past year will be presented. For more information : staff.association@cern.ch | T&eacu...

  5. Exhibition

    CERN Multimedia

    Staff Association

    2016-01-01

    Encounters Hanne Blitz From February 1st to 12th 2016 CERN Meyrin, Main Building What is our reaction to a first encounter with a tourist attraction? Contemporary Dutch painter Hanne Blitz captures visitors' responses to art and architecture, sweeping vistas and symbolic memorials. Encounters, a series of oil paintings curated specially for this CERN exhibition, depicts tourists visiting cultural highlights around the world. A thought-provoking journey not to be missed, and a tip of the hat to CERN's large Hadron Collider.

  6. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Sintropie Flavio Pellegrini From 13 to 24 March 2017 CERN Meyrin, Main Building Energia imprigionata - Flavio Pellegrini. The exhibition is composed by eleven wood artworks with the expression of movement as theme. The artworks are the result of harmonics math applied to sculpture. The powerful black colour is dominated by the light source, generating reflexes and modulations. The result is a continuous variation of perspective visions. The works generate, at a first approach, an emotion of mystery and incomprehension, only a deeper contemplation lets one discover entangling and mutative details, evidencing the elegance of the lines and letting the meaning emerge. For more information : staff.association@cern.ch | Tél: 022 766 37 38

  7. Embryonic stem cells deficient for Brca2 or Blm exhibit divergent genotoxic profiles that support opposing activities during homologous recombination

    Energy Technology Data Exchange (ETDEWEB)

    Marple, Teresa [Department of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive San Antonio, TX 78245-3207 (United States); Kim, Tae Moon [Department of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive San Antonio, TX 78245-3207 (United States); Hasty, Paul [Department of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive San Antonio, TX 78245-3207 (United States)]. E-mail: hastye@uthscsa.edu

    2006-12-01

    The breast cancer susceptibility protein, Brca2 and the RecQ helicase, Blm (Bloom syndrome mutated) are tumor suppressors that maintain genome integrity, at least in part, through homologous recombination (HR). Brca2 facilitates HR by interacting with Rad51 in multiple regions, the BRC motifs encoded by exon 11 and a single domain encoded by exon 27; however, the exact importance of these regions is not fully understood. Blm also interacts with Rad51 and appears to suppress HR in most circumstances; however, its yeast homologue Sgs1 facilitates HR in response to some genotoxins. To better understand the biological importance of these two proteins, we performed a genotoxic screen on mouse embryonic stem (ES) cells impaired for either Brca2 or Blm to establish their genotoxic profiles (a cellular dose-response to a wide range of agents). This is the first side-by-side comparison of these two proteins in an identical genetic background. We compared cells deleted for Brca2 exon 27 to cells reduced for Blm expression and find that the Brca2- and Blm-impaired cells exhibit genotoxic profiles that reflect opposing activities during HR. Cells deleted for Brca2 exon 27 are hypersensitive to {gamma}-radiation, streptonigrin, mitomycin C and camptothecin and mildly resistant to ICRF-193 which is similar to HR defective cells null for Rad54. By contrast, Blm-impaired cells are hypersensitive to ICRF-193, mildly resistant to camptothecin and mitomycin C and more strongly resistant to hydroxyurea. These divergent profiles support the notion that Brca2 and Blm perform opposing functions during HR in mouse ES cells.

  8. Cloning and Functional Analysis of cDNAs with Open Reading Frames for 300 Previously Undefined Genes Expressed in CD34+ Hematopoietic Stem/Progenitor Cells

    Science.gov (United States)

    Zhang, Qing-Hua; Ye, Min; Wu, Xin-Yan; Ren, Shuang-Xi; Zhao, Meng; Zhao, Chun-Jun; Fu, Gang; Shen, Yu; Fan, Hui-Yong; Lu, Gang; Zhong, Ming; Xu, Xiang-Ru; Han, Ze-Guang; Zhang, Ji-Wang; Tao, Jiong; Huang, Qiu-Hua; Zhou, Jun; Hu, Geng-Xi; Gu, Jian; Chen, Sai-Juan; Chen, Zhu

    2000-01-01

    Three hundred cDNAs containing putatively entire open reading frames (ORFs) for previously undefined genes were obtained from CD34+ hematopoietic stem/progenitor cells (HSPCs), based on EST cataloging, clone sequencing, in silico cloning, and rapid amplification of cDNA ends (RACE). The cDNA sizes ranged from 360 to 3496 bp and their ORFs coded for peptides of 58–752 amino acids. Public database search indicated that 225 cDNAs exhibited sequence similarities to genes identified across a variety of species. Homology analysis led to the recognition of 50 basic structural motifs/domains among these cDNAs. Genomic exon–intron organization could be established in 243 genes by integration of cDNA data with genome sequence information. Interestingly, a new gene named as HSPC070 on 3p was found to share a sequence of 105bp in 3′ UTR with RAF gene in reversed transcription orientation. Chromosomal localizations were obtained using electronic mapping for 192 genes and with radiation hybrid (RH) for 38 genes. Macroarray technique was applied to screen the gene expression patterns in five hematopoietic cell lines (NB4, HL60, U937, K562, and Jurkat) and a number of genes with differential expression were found. The resource work has provided a wide range of information useful not only for expression genomics and annotation of genomic DNA sequence, but also for further research on the function of genes involved in hematopoietic development and differentiation. [The sequence data described in this paper have been submitted to the GenBank data library under the accession nos. listed in Table 1, pp 1548–1552.] PMID:11042152

  9. Cloning of two individual cDNAS encoding 9-cis-epoxycarotenoid dioxygenase from Gentiana lutea, their tissue-specific expression and physiological effect in transgenic tobacco.

    Science.gov (United States)

    Zhu, Changfu; Kauder, Friedrich; Römer, Susanne; Sandmann, Gerhard

    2007-02-01

    Two 9-cis-epoxycarotenoid dioxygenase (NCED) cDNAs have been cloned from a petal library of Gentiana lutea. Both cDNAs carry a putative transit sequence for chloroplast import and differ mainly in their length and the 5'-flanking regions. GlNCED1 was evolutionary closely related to Arabidopsis thaliana NCED6 whereas GlNCED2 showed highest homology to tomato NCED1 and A. thaliana NCED3. The amounts of GlNCED2 transcript were below Northern detection in G. lutea. In contrast, GlNCED1 was specifically expressed at higher levels in developing flowers when petals start appearing. By genetic engineering of tobacco with coding regions of either gene under a constitutive promoter, their function was further analyzed. Although mRNA of both genes was detectable in the corresponding transgenic plants, a physiological effect was only found for GlNCED1 but not for GlNCED2. In germination experiments of GlNCED1 transgenic lines, delayed radicle formation and cotyledon appearance were observed. However, the transformants exhibited no improved tolerance against desiccation stress. In contrast to other plants with over-expressed NCEDs, prolonged delay of seed germination is the only abscisic-acid-related phenotypic effect in the GlNCED1 transgenic lines.

  10. Coding sequence of human rho cDNAs clone 6 and clone 9

    Energy Technology Data Exchange (ETDEWEB)

    Chardin, P; Madaule, P; Tavitian, A

    1988-03-25

    The authors have isolated human cDNAs including the complete coding sequence for two rho proteins corresponding to the incomplete isolates previously described as clone 6 and clone 9. The deduced a.a. sequences, when compared to the a.a. sequence deduced from clone 12 cDNA, show that there are in human at least three highly homologous rho genes. They suggest that clone 12 be named rhoA, clone 6 : rhoB and clone 9 : rhoC. RhoA, B and C proteins display approx. 30% a.a. identity with ras proteins,. mainly clustered in four highly homologous internal regions corresponding to the GTP binding site; however at least one significant difference is found; the 3 rho proteins have an Alanine in position corresponding to ras Glycine 13, suggesting that rho and ras proteins might have slightly different biochemical properties.

  11. Molecular cloning of cDNAs which are highly overexpressed in mitoxantrone-resistant cells

    DEFF Research Database (Denmark)

    Miyake, K; Mickley, L; Litman, Thomas

    1999-01-01

    mitoxantrone-resistant S1-M1-80 human colon carcinoma cells was screened by differential hybridization. Two cDNAs of different lengths were isolated and designated MXR1 and MXR2. Sequencing revealed a high degree of homology for the cDNAs with Expressed Sequence Tag sequences previously identified as belonging...... to an ATP binding cassette transporter. Homology to the Drosophila white gene and its homologues was found for the predicted amino acid sequence. Using either cDNA as a probe in a Northern analysis demonstrated high levels of expression in the S1-M1-80 cells and in the human breast cancer subline, MCF-7 Ad......Vp3000. Levels were lower in earlier steps of selection, and in partial revertants. The gene is amplified 10-12-fold in the MCF-7 AdVp3000 cells, but not in the S1-M1-80 cells These studies are consistent with the identification of a new ATP binding cassette transporter, which is overexpressed...

  12. Cloning of cDNAs encoding new peptides of the dermaseptin-family.

    Science.gov (United States)

    Wechselberger, C

    1998-10-14

    Dermaseptins are a group of basic (lysine-rich) peptides, 27-34 amino acids in length and involved in the defense of frog skin against microbial invasion. By using a degenerated oligonucleotide primer binding to the 5'-untranslated region of previously characterized cDNAs of these peptides, it was possible to identify new members of the dermaseptin family in the South American frogs Agalychnis annae and Pachymedusa dacnicolor. Amino acid alignment and secondary structure prediction reveals, that only five of the deduced peptides can be supposed to be also functional homologs to the known dermaseptins from Phyllomedusa bicolor and Phyllomedusa sauvagei. The remaining six peptides described in this paper have not been isolated and characterized yet.

  13. Cloning and molecular characterization of the cDNAs encoding the variable regions of an anti-CD20 monoclonal antibody.

    Science.gov (United States)

    Shanehbandi, Dariush; Majidi, Jafar; Kazemi, Tohid; Baradaran, Behzad; Aghebati-Maleki, Leili

    2017-01-01

    CD20-based targeting of B-cells in hematologic malignancies and autoimmune disorders is associated with outstanding clinical outcomes. Isolation and characterization of VH and VL cDNAs encoding the variable regions of the heavy and light chains of monoclonal antibodies (MAb) is necessary to produce next generation MAbs and their derivatives such as bispecific antibodies (bsAb) and single-chain variable fragments (scFv). This study was aimed at cloning and characterization of the VH and VL cDNAs from a hybridoma cell line producing an anti-CD20 MAb. VH and VL fragments were amplified, cloned and characterized. Furthermore, amino acid sequences of VH, VL and corresponding complementarity-determining regions (CDR) were determined and compared with those of four approved MAbs including Rituximab (RTX), Ibritumomab tiuxetan, Ofatumumab and GA101. The cloned VH and VL cDNAs were found to be functional and follow a consensus pattern. Amino acid sequences corresponding to the VH and VL fragments also indicated noticeable homologies to those of RTX and Ibritumomab. Furthermore, amino acid sequences of the relating CDRs had remarkable similarities to their counterparts in RTX and Ibritumomab. Successful recovery of VH and VL fragments encourages the development of novel CD20 targeting bsAbs, scFvs, antibody conjugates and T-cells armed with chimeric antigen receptors.

  14. Persistent homology of complex networks

    International Nuclear Information System (INIS)

    Horak, Danijela; Maletić, Slobodan; Rajković, Milan

    2009-01-01

    Long-lived topological features are distinguished from short-lived ones (considered as topological noise) in simplicial complexes constructed from complex networks. A new topological invariant, persistent homology, is determined and presented as a parameterized version of a Betti number. Complex networks with distinct degree distributions exhibit distinct persistent topological features. Persistent topological attributes, shown to be related to the robust quality of networks, also reflect the deficiency in certain connectivity properties of networks. Random networks, networks with exponential connectivity distribution and scale-free networks were considered for homological persistency analysis

  15. Cloning and characterization of cDNAs encoding the complete sequence of decay-accelerating factor of human complement

    International Nuclear Information System (INIS)

    Medof, M.E.; Lublin, D.M.; Holers, V.M.; Ayers, D.J.; Getty, R.R.; Leykam, J.F.; Atkinson, J.P.; Tykocinski, M.L.

    1987-01-01

    cDNAs encoding the complement decay-accelerating factor (DAF) were isolated from HeLa and differentiated HL-60 λgt cDNA libraries by screening with a codon preference oligonucleotide corresponding to DAF NH 2 -terminal amino acids 3-14. The composite cDNA sequence showed a 347-amino acid protein preceded by an NH 2 -terminal leader peptide sequence. The translated sequence beginning at the DAF NH 2 terminus encodes four contiguous ≅ 61-amino acid long repetitive units of internal homology. The repetitive regions contain four conserved cysteines, one proline, one glycine, one glycine/alanine, four leucines/isoleucines/valines, one serine, three tyrosines/phenylalanines, and on tryptophan and show striking homology to similar regions previously identified in factor B, C2, C4 binding protein, factor H, C1r, factor XIII, interleukin 2 receptor, and serum β 2 -glycoprotein I. The consensus repeats are attached to a 70-amino acid long segment rich in serine and threonine (potential O-glycosylation sites), which is in turn followed by a stretch of hydrophobic amino acids. RNA blot analysis of HeLa and HL-60 RNA revealed three DAF mRNA species of 3.1, 2.7, and 2.0 kilobases. The results indicate that portions of the DAF gene may have evolved from a DNA element common to the above proteins, that DAF cDNA predicts a COOH-terminal anchoring polypeptide, and that distinct species of DAF message are elaborated in cells

  16. Technology Exhibition

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1979-09-15

    Linked to the 25th Anniversary celebrations, an exhibition of some of CERN's technological achievements was opened on 22 June. Set up in a new 600 m{sup 2} Exhibition Hall on the CERN site, the exhibition is divided into eight technology areas — magnets, vacuum, computers and data handling, survey and alignment, radiation protection, beam monitoring and handling, detectors, and workshop techniques.

  17. Immersive Exhibitions

    DEFF Research Database (Denmark)

    Achiam, Marianne

    2015-01-01

    The immersive exhibition is a specialized exhibition genre in museums, which creates the illusion of time and place by representing key characteristics of a reference world and by integrating the visitor in this three-dimensionally reconstructed world (Mortensen 2010). A successful representation...... of the reference world depends on three criteria: whether the exhibition is staged as a coherent whole with all the displayed objects supporting the representation, whether the visitor is integrated as a component of the exhibition, and whether the content and message of the exhibition become dramatized...

  18. Immunoselection of cDNAs to avian intestinal calcium binding protein 28K and a novel calmodulin-like protein: assessment of mRNA regulation by the Vitamin D hormone

    International Nuclear Information System (INIS)

    Mangelsdorf, D.J.; Komm, B.S.; McDonnell, D.P.; Pike, J.W.; Haussler, M.R.

    1987-01-01

    Calcium's role in a variety of cellular processes has been well documented. The storage, distribution, and delivery of calcium are regulated by a family of binding proteins including troponin C, calmodulin, parvalbumin, and vitamin D dependent calcium binding protein (CaBP-28), all of which have evolved from a common ancestral gene. To evaluate vitamin D regulation of gene transcription, a CaBP-28 cDNA (767 base pairs) was isolated from a chicken intestine λgt11 library utilizing a polyvalent CaBP-28 antibody as a probe. Coincident with the identification of the CaBP-28 cDNA, a group of cDNAs also was isolated (with the anti-CaBP-28 antibody) that demonstrated 84% nucleotide homology and 99% deduced amino acid homology with chicken brain calmodulin (CaM). This new CaM-like cDNA was named neoCaM. There is little nucleotide homology between the CaBP-28 cDNA and neoCaM. The CaBP-28 cDNA hybridizes with three transcripts of 2000, 2900, and 3300 bases which are dramatically induced by 1,25-dihydroxyvitamin D 3 [1,25(OH) 2 D 3 ], while the neoCaM cDNA recognizes three distinct (from CaBP-28) transcripts. Two of these mRNAs are 1400 and 1800 bases as described for brain CaM, but another large 4000-base transcript is detected with neoCaM. Neither the CaM nor the neoCaM transcript reveals any modulation by 1,25(OH) 2 D 3 . Herein, the authors discuss the possible significance of not only the isolation of both cDNAs with a single antibody but also the relation of neoCaM to other well-characterized CaM cDNAs

  19. Exhibit Engineering

    DEFF Research Database (Denmark)

    Mortensen, Marianne Foss

    Science museums define the objectives of their exhibitions in terms of visitor learning outcomes. Yet, exhibit designers lack theoretical and empirical research findings on which to base the creation of such educational environments. Here, this shortcoming is addressed through the development...... of tools and processes to guide the design of educational science exhibits. The guiding paradigm for this development is design-based research, which is characterised by an iterative cycle of design, enactment, and analysis. In the design phase, an educational intervention is planned and carried out based...... on the generation of theoretical ideas for exhibit design is offered in a fourth and parallel research undertaking, namely the application of the notion of cultural border-crossing to a hypothetical case of exhibit design....

  20. Pure homology of algebraic varieties

    OpenAIRE

    Weber, Andrzej

    2003-01-01

    We show that for a complete complex algebraic variety the pure component of homology coincides with the image of intersection homology. Therefore pure homology is topologically invariant. To obtain slightly more general results we introduce "image homology" for noncomplete varieties.

  1. Lectures on functor homology

    CERN Document Server

    Touzé, Antoine

    2015-01-01

    This book features a series of lectures that explores three different fields in which functor homology (short for homological algebra in functor categories) has recently played a significant role. For each of these applications, the functor viewpoint provides both essential insights and new methods for tackling difficult mathematical problems. In the lectures by Aurélien Djament, polynomial functors appear as coefficients in the homology of infinite families of classical groups, e.g. general linear groups or symplectic groups, and their stabilization. Djament’s theorem states that this stable homology can be computed using only the homology with trivial coefficients and the manageable functor homology. The series includes an intriguing development of Scorichenko’s unpublished results. The lectures by Wilberd van der Kallen lead to the solution of the general cohomological finite generation problem, extending Hilbert’s fourteenth problem and its solution to the context of cohomology. The focus here is o...

  2. Expression of cDNAs in human Natural Killer cell lines by retroviral transduction.

    Science.gov (United States)

    Miah, S M Shahjahan; Campbell, Kerry S

    2010-01-01

    Human NK-like cell lines are difficult to transfect using standard mammalian expression vectors and conventional transfection protocols, but they are susceptible to retroviral transduction as a means to introduce cDNAs. Our laboratory has exploited this technique to study a number of receptors in human NK cell lines. The method utilizes a bicistronic retroviral vector that co-expresses either drug resistance or enhanced green fluorescent protein (EGFP) in parallel with the gene of interest. After a single infection with recombinant retrovirus, transduced NK cells can be sorted for expression of EGFP or the transduced cell surface marker. Alternatively, cells expressing the transduced cDNAs can be selected for by treatment with neomycin, puromycin, or hygromycin. Using this method, the sorted/selected cells uniformly express the gene of interest and the expression is stable for many weeks of culture.

  3. Homological stabilizer codes

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Jonas T., E-mail: jonastyleranderson@gmail.com

    2013-03-15

    In this paper we define homological stabilizer codes on qubits which encompass codes such as Kitaev's toric code and the topological color codes. These codes are defined solely by the graphs they reside on. This feature allows us to use properties of topological graph theory to determine the graphs which are suitable as homological stabilizer codes. We then show that all toric codes are equivalent to homological stabilizer codes on 4-valent graphs. We show that the topological color codes and toric codes correspond to two distinct classes of graphs. We define the notion of label set equivalencies and show that under a small set of constraints the only homological stabilizer codes without local logical operators are equivalent to Kitaev's toric code or to the topological color codes. - Highlights: Black-Right-Pointing-Pointer We show that Kitaev's toric codes are equivalent to homological stabilizer codes on 4-valent graphs. Black-Right-Pointing-Pointer We show that toric codes and color codes correspond to homological stabilizer codes on distinct graphs. Black-Right-Pointing-Pointer We find and classify all 2D homological stabilizer codes. Black-Right-Pointing-Pointer We find optimal codes among the homological stabilizer codes.

  4. Human Exhibitions

    DEFF Research Database (Denmark)

    Andreassen, Rikke

    light on the staging of exhibitions, the daily life of the exhibitees, the wider connections between shows across Europe and the thinking of the time on matters of race, science, gender and sexuality. A window onto contemporary racial understandings, the book presents interviews with the descendants...... of displayed people, connecting the attitudes and science of the past with both our (continued) modern fascination with ‘the exotic’, and contemporary language and popular culture. As such, it will be of interest to scholars of sociology, anthropology and history working in the areas of gender and sexuality...

  5. Riboflavin accumulation and characterization of cDNAs encoding lumazine synthase and riboflavin synthase in bitter melon (Momordica charantia).

    Science.gov (United States)

    Tuan, Pham Anh; Kim, Jae Kwang; Lee, Sanghyun; Chae, Soo Cheon; Park, Sang Un

    2012-12-05

    Riboflavin (vitamin B2) is the universal precursor of the coenzymes flavin mononucleotide and flavin adenine dinucleotide--cofactors that are essential for the activity of a wide variety of metabolic enzymes in animals, plants, and microbes. Using the RACE PCR approach, cDNAs encoding lumazine synthase (McLS) and riboflavin synthase (McRS), which catalyze the last two steps in the riboflavin biosynthetic pathway, were cloned from bitter melon (Momordica charantia), a popular vegetable crop in Asia. Amino acid sequence alignments indicated that McLS and McRS share high sequence identity with other orthologous genes and carry an N-terminal extension, which is reported to be a plastid-targeting sequence. Organ expression analysis using quantitative real-time RT PCR showed that McLS and McRS were constitutively expressed in M. charantia, with the strongest expression levels observed during the last stage of fruit ripening (stage 6). This correlated with the highest level of riboflavin content, which was detected during ripening stage 6 by HPLC analysis. McLS and McRS were highly expressed in the young leaves and flowers, whereas roots exhibited the highest accumulation of riboflavin. The cloning and characterization of McLS and McRS from M. charantia may aid the metabolic engineering of vitamin B2 in crops.

  6. Geometric homology revisited

    OpenAIRE

    Ruffino, Fabio Ferrari

    2013-01-01

    Given a cohomology theory, there is a well-known abstract way to define the dual homology theory using the theory of spectra. In [4] the author provides a more geometric construction of the homology theory, using a generalization of the bordism groups. Such a generalization involves in its definition the vector bundle modification, which is a particular case of the Gysin map. In this paper we provide a more natural variant of that construction, which replaces the vector bundle modification wi...

  7. Human mast cell tryptase: Multiple cDNAs and genes reveal a multigene serine protease family

    International Nuclear Information System (INIS)

    Vanderslice, P.; Ballinger, S.M.; Tam, E.K.; Goldstein, S.M.; Craik, C.S.; Caughey, G.H.

    1990-01-01

    Three different cDNAs and a gene encoding human skin mast cell tryptase have been cloned and sequenced in their entirety. The deduced amino acid sequences reveal a 30-amino acid prepropeptide followed by a 245-amino acid catalytic domain. The C-terminal undecapeptide of the human preprosequence is identical in dog tryptase and appears to be part of a prosequence unique among serine proteases. The differences among the three human tryptase catalytic domains include the loss of a consensus N-glycosylation site in one cDNA, which may explain some of the heterogeneity in size and susceptibility to deglycosylation seen in tryptase preparations. All three tryptase cDNAs are distinct from a recently reported cDNA obtained from a human lung mast cell library. A skin tryptase cDNA was used to isolate a human tryptase gene, the exons of which match one of the skin-derived cDNAs. The organization of the ∼1.8-kilobase-pair tryptase gene is unique and is not closely related to that of any other mast cell or leukocyte serine protease. The 5' regulatory regions of the gene share features with those of other serine proteases, including mast cell chymase, but are unusual in being separated from the protein-coding sequence by an intron. High-stringency hybridization of a human genomic DNA blot with a fragment of the tryptase gene confirms the presence of multiple tryptase genes. These findings provide genetic evidence that human mast cell tryptases are the products of a multigene family

  8. Investigating homology between proteins using energetic profiles.

    Science.gov (United States)

    Wrabl, James O; Hilser, Vincent J

    2010-03-26

    Accumulated experimental observations demonstrate that protein stability is often preserved upon conservative point mutation. In contrast, less is known about the effects of large sequence or structure changes on the stability of a particular fold. Almost completely unknown is the degree to which stability of different regions of a protein is generally preserved throughout evolution. In this work, these questions are addressed through thermodynamic analysis of a large representative sample of protein fold space based on remote, yet accepted, homology. More than 3,000 proteins were computationally analyzed using the structural-thermodynamic algorithm COREX/BEST. Estimated position-specific stability (i.e., local Gibbs free energy of folding) and its component enthalpy and entropy were quantitatively compared between all proteins in the sample according to all-vs.-all pairwise structural alignment. It was discovered that the local stabilities of homologous pairs were significantly more correlated than those of non-homologous pairs, indicating that local stability was indeed generally conserved throughout evolution. However, the position-specific enthalpy and entropy underlying stability were less correlated, suggesting that the overall regional stability of a protein was more important than the thermodynamic mechanism utilized to achieve that stability. Finally, two different types of statistically exceptional evolutionary structure-thermodynamic relationships were noted. First, many homologous proteins contained regions of similar thermodynamics despite localized structure change, suggesting a thermodynamic mechanism enabling evolutionary fold change. Second, some homologous proteins with extremely similar structures nonetheless exhibited different local stabilities, a phenomenon previously observed experimentally in this laboratory. These two observations, in conjunction with the principal conclusion that homologous proteins generally conserved local stability, may

  9. Investigating homology between proteins using energetic profiles.

    Directory of Open Access Journals (Sweden)

    James O Wrabl

    2010-03-01

    Full Text Available Accumulated experimental observations demonstrate that protein stability is often preserved upon conservative point mutation. In contrast, less is known about the effects of large sequence or structure changes on the stability of a particular fold. Almost completely unknown is the degree to which stability of different regions of a protein is generally preserved throughout evolution. In this work, these questions are addressed through thermodynamic analysis of a large representative sample of protein fold space based on remote, yet accepted, homology. More than 3,000 proteins were computationally analyzed using the structural-thermodynamic algorithm COREX/BEST. Estimated position-specific stability (i.e., local Gibbs free energy of folding and its component enthalpy and entropy were quantitatively compared between all proteins in the sample according to all-vs.-all pairwise structural alignment. It was discovered that the local stabilities of homologous pairs were significantly more correlated than those of non-homologous pairs, indicating that local stability was indeed generally conserved throughout evolution. However, the position-specific enthalpy and entropy underlying stability were less correlated, suggesting that the overall regional stability of a protein was more important than the thermodynamic mechanism utilized to achieve that stability. Finally, two different types of statistically exceptional evolutionary structure-thermodynamic relationships were noted. First, many homologous proteins contained regions of similar thermodynamics despite localized structure change, suggesting a thermodynamic mechanism enabling evolutionary fold change. Second, some homologous proteins with extremely similar structures nonetheless exhibited different local stabilities, a phenomenon previously observed experimentally in this laboratory. These two observations, in conjunction with the principal conclusion that homologous proteins generally conserved

  10. Identification and characterization of the donkey CSN1S2 I and II cDNAs

    Directory of Open Access Journals (Sweden)

    Davide Nicodemo

    2010-04-01

    Full Text Available The αs2 casein, encoded by the CSN1S2 gene, is one of the three Calcium sensitive caseins present in the milk of ruminants of zootechnical interest and in the milk of Equidae species (horse and donkey. In the present study, we cloned, sequenced and analysed two different donkey CSN1S2 cDNAs that we called CSN1S2 I and CSN1S2 II. The first, which spans over a fragment of 1016 nt, is constituted by 19 exons and encodes for a predicted protein (called αs2-I of 221 aminoacids; the second, of which we determined the entire sequence (16 exons, encodes for a predicted peptide (called αs2-II of 168 aminoacids. Alternative splicing and genetic markers are reported for both genes.

  11. Characterization of cDNAs encoding human pyruvate dehydrogenase α subunit

    International Nuclear Information System (INIS)

    Ho, Lap; Wexler, I.D.; Liu, Techung; Thekkumkara, T.J.; Patel, M.S.

    1989-01-01

    A cDNA clone (1,423 base pairs) comprising the entire coding region of the precursor form of the α subunit of pyruvate dehydrogenase (E 1 α) has been isolated from a human liver cDNA library in phage λgt11. The first 29 amino acids deduced from the open reading frame correspond to a typical mitochondrial targeting leader sequence. The remaining 361 amino acids, starting at the N terminus with phenylalanine, represent the mature mitochondrial E 1 α peptide. The cDNA has 43 base pairs in the 5' untranslated region and 210 base pairs in the 3' untranslated region, including a polyadenylylation signal and a short poly(A) tract. The nucleotide sequence of human liver E 1 α cDNA was confirmed by the nucleotide sequences of three overlapping fragments generated from human liver and fibroblast RNA by reverse transcription and DNA amplification by the polymerase chain reaction. This consensus nucleotide sequence of human liver E 1 α cDNA resolves existing discrepancies among three previously reported human E 1 α cDNAs and provides the unambiguous reference sequence needed for the characterization of genetic mutations in pyruvate dehydrogenase-deficient patients

  12. Human Chromosome 21: Mapping of the chromosomes and cloning of cDNAs

    Energy Technology Data Exchange (ETDEWEB)

    Antonarakis, S.E.

    1991-09-01

    The objective of the research funded by DOE grant DE-FG02-89ER60857 from 6/15/89 to 8/31/91 was to contribute to the physical mapping of human chromosome 21 (HC21) by cloning large fragments of DNA into Yeast Artificial Chromosomes (YACs) and identify YACs that map on HC21. A total of 54 sequence tagged sites (STS) have been developed and mapped in our laboratory to HC21 and can be used as initial reference points for YAC identification and construction of overlapping clones. A small YAC library was constructed which is HC21 specific. DNA from somatic cell hybrid WAV17 or from flow-sorted HC21 was partially digested with EcoRI, ligated into vectors PJS97, PJS98, and YACs have been obtained with average size insert of more than 300 kb. This library has been deposited in D. Patterson's lab for the Joint YAC screening effort. Additional YAC libraries from ICI Pharmaceuticals or from Los Alamos National Laboratories have been screened with several STS and positive YACs have been identified. Work in progress includes screening of YAC libraries in order to construct overlapping clones, characterization of the cloning ends of YACs, characterization of additional STS and cloning of HC21 specific cDNAs. 15 refs., 2 figs., 5 tabs.

  13. cDNAs for the synthesis of cyclic carotenoids in petals of Gentiana lutea and their regulation during flower development.

    Science.gov (United States)

    Zhu, Changfu; Yamamura, Saburo; Nishihara, Masashiro; Koiwa, Hiroyuki; Sandmann, Gerhard

    2003-02-20

    cDNAs encoding lycopene epsilon -cyclase, lycopene beta-cyclase, beta-carotene hydroxylase and zeaxanthin epoxidase were isolated from a Gentiana lutea petal cDNA library. The function of all cDNAs was analyzed by complementation in Escherichia coli. Transcript levels during different stages of flower development of G. lutea were determined and compared to the carotenoid composition. Expression of all genes increased by a factor of up to 2, with the exception of the lycopene epsilon -cyclase gene. The transcript amount of the latter was strongly decreased. These results indicate that during flower development, carotenoid formation is enhanced. Moreover, metabolites are shifted away from the biosynthetic branch to lutein and are channeled into beta-carotene and derivatives.

  14. Signal sequence and keyword trap in silico for selection of full-length human cDNAs encoding secretion or membrane proteins from oligo-capped cDNA libraries.

    Science.gov (United States)

    Otsuki, Tetsuji; Ota, Toshio; Nishikawa, Tetsuo; Hayashi, Koji; Suzuki, Yutaka; Yamamoto, Jun-ichi; Wakamatsu, Ai; Kimura, Kouichi; Sakamoto, Katsuhiko; Hatano, Naoto; Kawai, Yuri; Ishii, Shizuko; Saito, Kaoru; Kojima, Shin-ichi; Sugiyama, Tomoyasu; Ono, Tetsuyoshi; Okano, Kazunori; Yoshikawa, Yoko; Aotsuka, Satoshi; Sasaki, Naokazu; Hattori, Atsushi; Okumura, Koji; Nagai, Keiichi; Sugano, Sumio; Isogai, Takao

    2005-01-01

    We have developed an in silico method of selection of human full-length cDNAs encoding secretion or membrane proteins from oligo-capped cDNA libraries. Fullness rates were increased to about 80% by combination of the oligo-capping method and ATGpr, software for prediction of translation start point and the coding potential. Then, using 5'-end single-pass sequences, cDNAs having the signal sequence were selected by PSORT ('signal sequence trap'). We also applied 'secretion or membrane protein-related keyword trap' based on the result of BLAST search against the SWISS-PROT database for the cDNAs which could not be selected by PSORT. Using the above procedures, 789 cDNAs were primarily selected and subjected to full-length sequencing, and 334 of these cDNAs were finally selected as novel. Most of the cDNAs (295 cDNAs: 88.3%) were predicted to encode secretion or membrane proteins. In particular, 165(80.5%) of the 205 cDNAs selected by PSORT were predicted to have signal sequences, while 70 (54.2%) of the 129 cDNAs selected by 'keyword trap' preserved the secretion or membrane protein-related keywords. Many important cDNAs were obtained, including transporters, receptors, and ligands, involved in significant cellular functions. Thus, an efficient method of selecting secretion or membrane protein-encoding cDNAs was developed by combining the above four procedures.

  15. Characterization and comparison of fatty acyl Delta6 desaturase cDNAs from freshwater and marine teleost fish species.

    Science.gov (United States)

    Zheng, X; Seiliez, I; Hastings, N; Tocher, D R; Panserat, S; Dickson, C A; Bergot, P; Teale, A J

    2004-10-01

    Fish are the most important dietary source of the n-3 highly unsaturated fatty acids (HUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), that have particularly important roles in human nutrition reflecting their roles in critical physiological processes. The objective of the study described here was to clone, functionally characterize and compare expressed fatty acid desaturase genes involved in the production of EPA and DHA in freshwater and marine teleost fish species. Putative fatty acid desaturase cDNAs were isolated and cloned from common carp (Cyprinus carpio) and turbot (Psetta maximus). The enzymic activities of the products of these cDNAs, together with those of cDNAs previously cloned from rainbow trout (Oncorhynchus mykiss) and gilthead sea bream (Sparus aurata), were determined by heterologous expression in the yeast Saccharomyces cerevisiae. The carp and turbot desaturase cDNAs included open reading frames (ORFs) of 1335 and 1338 base pairs, respectively, specifying proteins of 444 and 445 amino acids. The protein sequences possessed all the characteristic features of microsomal fatty acid desaturases, including three histidine boxes, two transmembrane regions, and N-terminal cytochrome b(5) domains containing the haem-binding motif, HPGG. Functional expression showed all four fish cDNAs encode basically unifunctional Delta6 fatty acid desaturase enzymes responsible for the first and rate-limiting step in the biosynthesis of HUFA from 18:3n-3 and 18:2n-6. All the fish desaturases were more active towards the n-3 substrate with 59.5%, 31.5%, 23.1% and 7.0% of 18:3n-3 being converted to 18:4n-3 in the case of turbot, trout, sea bream and carp, respectively. The enzymes also showed very low, probably physiologically insignificant, levels of Delta5 desaturase activity, but none of the products showed Delta4 desaturase activity. The cloning and characterization of desaturases from these fish is an important advance, as they are species in which

  16. Chemical shift homology in proteins

    International Nuclear Information System (INIS)

    Potts, Barbara C.M.; Chazin, Walter J.

    1998-01-01

    The degree of chemical shift similarity for homologous proteins has been determined from a chemical shift database of over 50 proteins representing a variety of families and folds, and spanning a wide range of sequence homologies. After sequence alignment, the similarity of the secondary chemical shifts of C α protons was examined as a function of amino acid sequence identity for 37 pairs of structurally homologous proteins. A correlation between sequence identity and secondary chemical shift rmsd was observed. Important insights are provided by examining the sequence identity of homologous proteins versus percentage of secondary chemical shifts that fall within 0.1 and 0.3 ppm thresholds. These results begin to establish practical guidelines for the extent of chemical shift similarity to expect among structurally homologous proteins

  17. Mod two homology and cohomology

    CERN Document Server

    Hausmann, Jean-Claude

    2014-01-01

    Cohomology and homology modulo 2 helps the reader grasp more readily the basics of a major tool in algebraic topology. Compared to a more general approach to (co)homology this refreshing approach has many pedagogical advantages: It leads more quickly to the essentials of the subject, An absence of signs and orientation considerations simplifies the theory, Computations and advanced applications can be presented at an earlier stage, Simple geometrical interpretations of (co)chains. Mod 2 (co)homology was developed in the first quarter of the twentieth century as an alternative to integral homology, before both became particular cases of (co)homology with arbitrary coefficients. The first chapters of this book may serve as a basis for a graduate-level introductory course to (co)homology. Simplicial and singular mod 2 (co)homology are introduced, with their products and Steenrod squares, as well as equivariant cohomology. Classical applications include Brouwer's fixed point theorem, Poincaré duality, Borsuk-Ula...

  18. Compositional Homology and Creative Thinking

    Directory of Open Access Journals (Sweden)

    Salvatore Tedesco

    2015-05-01

    Full Text Available The concept of homology is the most solid theoretical basis elaborated by the morphological thinking during its history. The enucleation of some general criteria for the interpretation of homology is today a fundamental tool for life sciences, and for restoring their own opening to the question of qualitative innovation that arose so powerfully in the original Darwinian project. The aim of this paper is to verify the possible uses of the concept of compositional homology in order to provide of an adequate understanding of the dynamics of creative thinking.

  19. Britain exhibition at CERN

    CERN Multimedia

    Bertin; CERN PhotoLab

    1969-01-01

    The United Kingdom inaugurated the Industrial Exhibitions in 1968, and it wasn't till 1971 that other countries staged exhibitions at CERN. This photo was taken in 1969, at the second British exhibition, where 16 companies were present.

  20. Digital collections and exhibits

    CERN Document Server

    Denzer, Juan

    2015-01-01

    Today's libraries are taking advantage of cutting-edge technologies such as flat panel displays using touch, sound, and hands-free motions to design amazing exhibits using everything from simple computer hardware to advanced technologies such as the Microsoft Kinect. Libraries of all types are striving to add new interactive experiences for their patrons through exciting digital exhibits, both online and off. Digital Collections and Exhibits takes away the mystery of designing stunning digital exhibits to spotlight library trea

  1. Exhibiting Epistemic Objects

    DEFF Research Database (Denmark)

    Tybjerg, Karin

    2017-01-01

    of exhibiting epistemic objects that utilize their knowledge-generating potential and allow them to continue to stimulate curiosity and generate knowledge in the exhibition. The epistemic potential of the objects can then be made to work together with the function of the exhibition as a knowledge-generating set...

  2. Discrimination? - Exhibition of posters

    OpenAIRE

    Jakimovska, Jana

    2017-01-01

    Participation in the exhibition with the students form the Art Academy. The exhibition consisted of 15 posters tackling the subjects of hate speech and discrimination. The exhibition happened thanks to the invitation of the Faculty of Law at UGD, and it was a part of a larger event of launching books on the aforementioned subjects.

  3. Cytochrome P450c17 (steroid 17α-hydroxylase/17,20 lyase): cloning of human adrenal and testis cDNAs indicates the same gene is expressed in both tissues

    International Nuclear Information System (INIS)

    Chung, B.; Picado-Leonard, J.; Haniu, M.; Bienkowski, M.; Hall, P.F.; Shively, J.E.; Miller, W.L.

    1987-01-01

    P450c17 is the single enzyme mediating both 17α-hydroxylase (steroid 17α-monooxygenase, EC 1.14.99.9) and 17,20 lyase activities in the synthesis of steroid hormones. It has been suggested that different P450c17 isozymes mediate these activities in the adrenal gland and testis. The authors sequenced 423 of the 509 amino acids (83%) of the porcine adrenal enzyme; based on this partial sequence, a 128-fold degenerate 17-mer was synthesized and used to screen a porcine adrenal cDNA library. This yielded a 380-base cloned cDNA, which in turn was used to isolate several human adrenal cDNAs. The longest of these, λ hac 17-2, is 1754 base pairs long and includes the full-length coding region, the complete 3'-untranslated region, and 41 bases of the 5'-untranslated region. This cDNA encodes a protein of 508 amino acids having a predicted molecular weight of 57,379.82. High-stringency screening of a human testicular cDNA library yielded a partial clone containing 1303 identical bases. RNA gel blots and nuclease S1-protection experiments confirm that the adrenal and testicular P450c17 mRNAs are indistinguishable. These data indicate that the testis possesses a P450c17 identical to that in the adrenal. The human amino acid sequence is 66.7% homologous to the corresponding regions of the porcine sequence, and the human cDNA and amino acid sequences are 80.1 and 70.3% homologous, respectively, to bovine adrenal P450c17 cDNA. Both comparisons indicate that a central region comprising amino acid residues 160-268 is hypervariable among these species of P450c17

  4. Homological stability of diffeomorphism groups

    DEFF Research Database (Denmark)

    Berglund, Alexander; Madsen, Ib Henning

    2013-01-01

    In this paper we prove a stability theorem for block diffeomorphisms of 2d -dimensional manifolds that are connected sums of S d ×S d . Combining this with a recent theorem of S. Galatius and O. Randal-Williams and Morlet’s lemma of disjunction, we determine the homology of the classifying space ...

  5. Induction of intrachromosomal homologous recombination in whole plants

    International Nuclear Information System (INIS)

    Puchta, H.; Swoboda, P.; Hohn, B.

    1995-01-01

    The influence of different factors on frequencies of intrachromosomal homologous recombination in whole Arabidopsis thaliana and tobacco plants was analyzed using a disrupted β-glucuronidase marker gene. Recombination frequencies were enhanced several fold by DNA damaging agents like UV-light or MMS (methyl methanesulfonate). Applying 3-methoxybenzamide (3-MB), an inhibitor of poly(ADP)ribose polymerase (PARP), an enzyme that is postulated to be involved in DNA repair, enhanced homologous recombination frequencies strongly. These findings indicate that homologous recombination is involved in DNA repair and can (at least partially) compensate for other DNA repair pathways. Indications that recombination in plants can be induced by environmental stress factors that are not likely to be involved in DNA metabolism were also found; Arabidopsis plants growing in a medium containing 0.1 M NaCl exhibited elevated recombination frequencies. The possible general effects of ‘environmental’ challenges on genome flexibility are discussed. (author)

  6. Cloning and sequencing of cDNAs specifying a novel class of phosphoribosyl diphosphate synthase in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Krath, Britta N.; Eriksen, Tina A.; Poulsen, Tim S.

    1999-01-01

    cDNAs specifying four active phosphoribosyl diphosphate synthase isozymes were isolated from an Arabidopsis thaliana cDNA library. In contrast to other phosphoribosyl diphosphate synthases the activity of two of the A. thaliana isozymes are independent of Pi. Amino acid sequence comparison and ph...

  7. Exhibition; Image display agency

    International Nuclear Information System (INIS)

    Normazlin Ismail

    2008-01-01

    This article touches on the role of Malaysian Nuclear Agency as nuclear research institutions to promote, develop and encourage the peaceful uses of nuclear technology in its agricultural, medical, manufacturing, industrial, health and environment for the development of the country running successfully. Maturity of Malaysian Nuclear Agency in dealing with nuclear technology that are very competitive and globalization cannot be denied. On this basis Malaysian Nuclear Agency was given the responsibility to strengthen the nuclear technology in Malaysia. One way is through an exhibition featuring the research, discoveries and new technology products of the nuclear technology. Through this exhibition is to promote the nuclear technology and introduce the image of the agency in the public eye. This article also states a number of exhibits entered by the Malaysian Nuclear Agency and achievements during the last exhibition. Authors hope that the exhibition can be intensified further in the future.

  8. Homological algebra in -abelian categories

    Indian Academy of Sciences (India)

    Deren Luo

    2017-08-16

    Aug 16, 2017 ... Homological algebra in n-abelian categories. 627. We recall the Comparison lemma, together with its dual, plays a central role in the sequel. Lemma 2.1 [13, Comparison lemma 2.1]. Let C be an additive category and X ∈ Ch. ≥0(C) a complex such that for all k ≥ 0the morphism dk+1. X is a weak cokernel ...

  9. Rational Homological Stability for Automorphisms of Manifolds

    DEFF Research Database (Denmark)

    Grey, Matthias

    In this thesis we prove rational homological stability for the classifying spaces of the homotopy automorphisms and block di↵eomorphisms of iterated connected sums of products of spheres of a certain connectivity.The results in particular apply to the manifolds       Npg,q  = (#g(Sp x Sq)) - int...... with coefficients in the homology of the universal covering, which is studied using rational homology theory. The result for the block di↵eomorphisms is deduced from the homological stability for the homotopy automorphisms upon using Surgery theory. Themain theorems of this thesis extend the homological stability...

  10. Council Chamber exhibition

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    To complete the revamp of CERN’s Council Chamber, a new exhibition is being installed just in time for the June Council meetings.   Panels will showcase highlights of CERN’s history, using some of the content prepared for the exhibitions marking 50 years of the PS, which were displayed in the main building last November. The previous photo exhibition in the Council Chamber stopped at the 1970s. To avoid the new panels becoming quickly out of date, photos are grouped together around specific infrastructures, rather than following a classic time-line. “We have put the focus on the accelerators – the world-class facilities that CERN has been offering researchers over the years, from the well-known large colliders to the lesser-known smaller facilities,” says Emma Sanders, who worked on the content. The new exhibition will be featured in a future issue of the Bulletin with photos and an interview with Fabienne Marcastel, designer of the exhibit...

  11. EXHIBITION: Accelerated Particles

    CERN Multimedia

    2004-01-01

    An exhibition of plastic arts and two evenings of performances by sound and visual artists as part of CERN's 50th anniversary celebrations. Fifty candles for CERN, an international laboratory renowned for fundamental research, is a cause for celebration. Since March this year, Geneva and neighbouring parts of France have been the venues for a wealth of small and large-scale events, which will continue until November. Given CERN's location in the commune of Meyrin, the ForuMeyrin is hosting exhibitions of plastic arts and performances entitled: Accelerated Particles. Several works will be exhibited and performed in two 'salons'. Salon des matières: An exhibition of plastic arts From Tues 12 October to Wed 3 November 2004 Tuesdays to Fridays: 16:00 to 19:00 Saturdays: 14:00 to 18:00 Exhibition open late on performance nights, entrance free Salon des particules: Musical and visual performances Tues 12 and Mon 25 October from 20:00 to 23:00 Preview evening for both events: Tues 12 October from 18:...

  12. Kuranishi homology and Kuranishi cohomology

    OpenAIRE

    Joyce, Dominic

    2007-01-01

    A Kuranishi space is a topological space with a Kuranishi structure, defined by Fukaya and Ono. Kuranishi structures occur naturally on moduli spaces of J-holomorphic curves in symplectic geometry. Let Y be an orbifold and R a commutative ring or Q-algebra. We define two kinds of Kuranishi homology KH_*(Y;R). The chain complex KC_*(Y;R) defining KH_*(Y;R) is spanned over R by [X,f,G], for X a compact oriented Kuranishi space with corners, f : X --> Y smooth, and G "gauge-fixing data" which ma...

  13. Clustering evolving proteins into homologous families.

    Science.gov (United States)

    Chan, Cheong Xin; Mahbob, Maisarah; Ragan, Mark A

    2013-04-08

    Clustering sequences into groups of putative homologs (families) is a critical first step in many areas of comparative biology and bioinformatics. The performance of clustering approaches in delineating biologically meaningful families depends strongly on characteristics of the data, including content bias and degree of divergence. New, highly scalable methods have recently been introduced to cluster the very large datasets being generated by next-generation sequencing technologies. However, there has been little systematic investigation of how characteristics of the data impact the performance of these approaches. Using clusters from a manually curated dataset as reference, we examined the performance of a widely used graph-based Markov clustering algorithm (MCL) and a greedy heuristic approach (UCLUST) in delineating protein families coded by three sets of bacterial genomes of different G+C content. Both MCL and UCLUST generated clusters that are comparable to the reference sets at specific parameter settings, although UCLUST tends to under-cluster compositionally biased sequences (G+C content 33% and 66%). Using simulated data, we sought to assess the individual effects of sequence divergence, rate heterogeneity, and underlying G+C content. Performance decreased with increasing sequence divergence, decreasing among-site rate variation, and increasing G+C bias. Two MCL-based methods recovered the simulated families more accurately than did UCLUST. MCL using local alignment distances is more robust across the investigated range of sequence features than are greedy heuristics using distances based on global alignment. Our results demonstrate that sequence divergence, rate heterogeneity and content bias can individually and in combination affect the accuracy with which MCL and UCLUST can recover homologous protein families. For application to data that are more divergent, and exhibit higher among-site rate variation and/or content bias, MCL may often be the better

  14. Multiscale analysis of nonlinear systems using computational homology

    Energy Technology Data Exchange (ETDEWEB)

    Konstantin Mischaikow; Michael Schatz; William Kalies; Thomas Wanner

    2010-05-24

    This is a collaborative project between the principal investigators. However, as is to be expected, different PIs have greater focus on different aspects of the project. This report lists these major directions of research which were pursued during the funding period: (1) Computational Homology in Fluids - For the computational homology effort in thermal convection, the focus of the work during the first two years of the funding period included: (1) A clear demonstration that homology can sensitively detect the presence or absence of an important flow symmetry, (2) An investigation of homology as a probe for flow dynamics, and (3) The construction of a new convection apparatus for probing the effects of large-aspect-ratio. (2) Computational Homology in Cardiac Dynamics - We have initiated an effort to test the use of homology in characterizing data from both laboratory experiments and numerical simulations of arrhythmia in the heart. Recently, the use of high speed, high sensitivity digital imaging in conjunction with voltage sensitive fluorescent dyes has enabled researchers to visualize electrical activity on the surface of cardiac tissue, both in vitro and in vivo. (3) Magnetohydrodynamics - A new research direction is to use computational homology to analyze results of large scale simulations of 2D turbulence in the presence of magnetic fields. Such simulations are relevant to the dynamics of black hole accretion disks. The complex flow patterns from simulations exhibit strong qualitative changes as a function of magnetic field strength. Efforts to characterize the pattern changes using Fourier methods and wavelet analysis have been unsuccessful. (4) Granular Flow - two experts in the area of granular media are studying 2D model experiments of earthquake dynamics where the stress fields can be measured; these stress fields from complex patterns of 'force chains' that may be amenable to analysis using computational homology. (5) Microstructure

  15. Multiscale analysis of nonlinear systems using computational homology

    Energy Technology Data Exchange (ETDEWEB)

    Konstantin Mischaikow, Rutgers University/Georgia Institute of Technology, Michael Schatz, Georgia Institute of Technology, William Kalies, Florida Atlantic University, Thomas Wanner,George Mason University

    2010-05-19

    This is a collaborative project between the principal investigators. However, as is to be expected, different PIs have greater focus on different aspects of the project. This report lists these major directions of research which were pursued during the funding period: (1) Computational Homology in Fluids - For the computational homology effort in thermal convection, the focus of the work during the first two years of the funding period included: (1) A clear demonstration that homology can sensitively detect the presence or absence of an important flow symmetry, (2) An investigation of homology as a probe for flow dynamics, and (3) The construction of a new convection apparatus for probing the effects of large-aspect-ratio. (2) Computational Homology in Cardiac Dynamics - We have initiated an effort to test the use of homology in characterizing data from both laboratory experiments and numerical simulations of arrhythmia in the heart. Recently, the use of high speed, high sensitivity digital imaging in conjunction with voltage sensitive fluorescent dyes has enabled researchers to visualize electrical activity on the surface of cardiac tissue, both in vitro and in vivo. (3) Magnetohydrodynamics - A new research direction is to use computational homology to analyze results of large scale simulations of 2D turbulence in the presence of magnetic fields. Such simulations are relevant to the dynamics of black hole accretion disks. The complex flow patterns from simulations exhibit strong qualitative changes as a function of magnetic field strength. Efforts to characterize the pattern changes using Fourier methods and wavelet analysis have been unsuccessful. (4) Granular Flow - two experts in the area of granular media are studying 2D model experiments of earthquake dynamics where the stress fields can be measured; these stress fields from complex patterns of 'force chains' that may be amenable to analysis using computational homology. (5) Microstructure

  16. EXHIBITION: Accelerated Particles

    CERN Multimedia

    2004-01-01

    http://www.cern.ch/cern50/ An exhibition of plastic arts and two evenings of performances by sound and visual artists as part of CERN's fiftieth anniversary celebrations. The fiftieth anniversary of a world famous organization like CERN, an international laboratory specializing in fundamental research, is a cause for celebration. Since March this year, Geneva and neighbouring parts of France have been the venues for a wealth of small and large-scale events, which will continue until November. Given CERN's location in the commune of Meyrin, the ForuMeyrin is hosting two "salons" consisting of an exhibition of plastic arts and evenings of music and visual arts performances with the collective title of "Accelerated Particles". Several works will be exhibited and performed. Salon des matières: An exhibition of plastic arts Until Wednesday 3 November 2004. Tuesdays to Fridays: 4.00 p.m. to 7.00 p.m. Saturdays: 2.00 p.m. to 6.00 p.m. Doors open late on the evening of the performances. Salon des ...

  17. Identification of the reptilian prolactin and its receptor cDNAs in the leopard gecko, Eublepharis macularius.

    Science.gov (United States)

    Kato, Keisuke; Ikemoto, Tadahiro; Park, Min Kyun

    2005-02-14

    In spite of their physiological significance, there is no available information about the nucleotide sequences of prolactin (PRL) and its receptor in reptilian species. In order to fill this gap, PRL and its receptor cDNAs were identified in a reptilian species, the leopard gecko Eublepharis macularius. The deduced leopard gecko PRL polypeptide showed high identities with the corresponding polypeptides of other reptiles. The leopard gecko PRL receptor (PRLR) was estimated to have tandem repeated regions in its extracellular domain, which had been originally found in avian PRLR. Molecular phylogenetic analysis suggests that these tandem repeated regions were generated by the duplication of the extracellular region in the latest common ancestor among reptiles and birds. In addition, tissue distributions of PRL and PRLR in the leopard gecko were examined by the reverse transcription-polymerase chain reaction (RT-PCR). PRLR mRNA was detected in all tissues examined and highly expressed in the whole brain, pituitary, intestine, kidney, ovary, oviduct and testis. Whereas, PRL mRNA was expressed in the whole brain, pituitary, ovary and testis. The co-expressions of PRL and its receptor in some extrapituitary organs suggest that PRL acts as an autocrine/paracrine factor in such organs of the leopard gecko.

  18. Dermatoxin and phylloxin from the waxy monkey frog, Phyllomedusa sauvagei: cloning of precursor cDNAs and structural characterization from lyophilized skin secretion.

    Science.gov (United States)

    Chen, Tianbao; Walker, Brian; Zhou, Mei; Shaw, Chris

    2005-07-15

    Amphibian skin is a morphologically, biochemically and physiologically complex organ that performs the wide range of functions necessary for amphibian survival. Here we describe the primary structures of representatives of two novel classes of amphibian skin antimicrobials, dermatoxin and phylloxin, from the skin secretion of Phyllomedusa sauvagei, deduced from their respective precursor encoding cDNAs cloned from a lyophilized skin secretion library. A degenerate primer, designed to a highly conserved domain in the 5'-untranslated region of analogous peptide precursor cDNAs from Phyllomedusa bicolor, was employed in a 3'-RACE reaction. Peptides with molecular masses coincident with precursor-deduced mature toxin peptides were identified in LC/MS fractions of skin secretion and primary structures were confirmed by MS/MS fragmentation. This integrated experimental approach can thus rapidly expedite the primary structural characterization of amphibian skin peptides in a manner that circumvents specimen sacrifice whilst preserving robustness of scientific data.

  19. International Space Station exhibit

    Science.gov (United States)

    2000-01-01

    The International Space Station (ISS) exhibit in StenniSphere at John C. Stennis Space Center in Hancock County, Miss., gives visitors an up-close look at the largest international peacetime project in history. Step inside a module of the ISS and glimpse how astronauts will live and work in space. Currently, 16 countries contribute resources and hardware to the ISS. When complete, the orbiting research facility will be larger than a football field.

  20. Upcycling CERN Exhibitions

    CERN Multimedia

    Katarina Anthony

    2015-01-01

    Summer is coming - and with it, a new Microcosm exhibition showcasing CERN (see here). But while the new exhibit is preparing to enchant visitors, many have been asking about the site's former content. Will it simply be out with the old and in with the new? Not as such!   The plasma ball from Microcosm is now on display at the LHCb site. As Microcosm's new content is moving in, its old content is moving up. From LHCb to IdeaSquare, former Microcosm displays and objects are being installed across the CERN site. "Microcosm featured many elements that were well suited to life outside of the exhibition," says Emma Sanders, Microcosm project leader in the EDU group. "We didn't want this popular content to go to waste, and so set out to find them new homes across CERN." The LHCb experiment has received a number of Microcosm favourites, including the Rutherford experiment, the cosmic ray display and the Thomson experiment. "We&...

  1. Molecular cloning and expression analysis of a cDNAs encoding androgenic gland hormone precursors from two Porcellionidae species, Porcellio scaber and P. dilatatus

    OpenAIRE

    Ohira, Tsuyoshi; Hasegawa, Yuriko; Okuno, Atsuro; Nagasawa, Hiromichi

    2003-01-01

    Male sexual characteristics in Crustacea are induced by androgenic gland hormone (AGH), which is produced by the male-specific androgenic gland. Recently, AGH in the terrestrial isopod Armadillidium vulgare was characterized and its cDNA cloned, the first example in which the structure of AGH was elucidated. We report here the molecular cloning of cDNAs encoding AGH precursors from two additional terrestrial isopods, Porcellio scaber and P. dilatatus. cDNA fragments encoding Porcellio scaber ...

  2. Persistent homology and string vacua

    Energy Technology Data Exchange (ETDEWEB)

    Cirafici, Michele [Center for Mathematical Analysis, Geometry and Dynamical Systems,Instituto Superior Técnico, Universidade de Lisboa,Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Institut des Hautes Études Scientifiques,Le Bois-Marie, 35 route de Chartres, F-91440 Bures-sur-Yvette (France)

    2016-03-08

    We use methods from topological data analysis to study the topological features of certain distributions of string vacua. Topological data analysis is a multi-scale approach used to analyze the topological features of a dataset by identifying which homological characteristics persist over a long range of scales. We apply these techniques in several contexts. We analyze N=2 vacua by focusing on certain distributions of Calabi-Yau varieties and Landau-Ginzburg models. We then turn to flux compactifications and discuss how we can use topological data analysis to extract physical information. Finally we apply these techniques to certain phenomenologically realistic heterotic models. We discuss the possibility of characterizing string vacua using the topological properties of their distributions.

  3. Equivariant ordinary homology and cohomology

    CERN Document Server

    Costenoble, Steven R

    2016-01-01

    Filling a gap in the literature, this book takes the reader to the frontiers of equivariant topology, the study of objects with specified symmetries. The discussion is motivated by reference to a list of instructive “toy” examples and calculations in what is a relatively unexplored field. The authors also provide a reading path for the first-time reader less interested in working through sophisticated machinery but still desiring a rigorous understanding of the main concepts. The subject’s classical counterparts, ordinary homology and cohomology, dating back to the work of Henri Poincaré in topology, are calculational and theoretical tools which are important in many parts of mathematics and theoretical physics, particularly in the study of manifolds. Similarly powerful tools have been lacking, however, in the context of equivariant topology. Aimed at advanced graduate students and researchers in algebraic topology and related fields, the book assumes knowledge of basic algebraic topology and group act...

  4. Online Exhibits & Concept Maps

    Science.gov (United States)

    Douma, M.

    2009-12-01

    Presenting the complexity of geosciences to the public via the Internet poses a number of challenges. For example, utilizing various - and sometimes redundant - Web 2.0 tools can quickly devour limited time. Do you tweet? Do you write press releases? Do you create an exhibit or concept map? The presentation will provide participants with a context for utilizing Web 2.0 tools by briefly highlighting methods of online scientific communication across several dimensions. It will address issues of: * breadth and depth (e.g. from narrow topics to well-rounded views), * presentation methods (e.g. from text to multimedia, from momentary to enduring), * sources and audiences (e.g. for experts or for the public, content developed by producers to that developed by users), * content display (e.g. from linear to non-linear, from instructive to entertaining), * barriers to entry (e.g. from an incumbent advantage to neophyte accessible, from amateur to professional), * cost and reach (e.g. from cheap to expensive), and * impact (e.g. the amount learned, from anonymity to brand awareness). Against this backdrop, the presentation will provide an overview of two methods of online information dissemination, exhibits and concept maps, using the WebExhibits online museum (www.webexhibits.org) and SpicyNodes information visualization tool (www.spicynodes.org) as examples, with tips on how geoscientists can use either to communicate their science. Richly interactive online exhibits can serve to engage a large audience, appeal to visitors with multiple learning styles, prompt exploration and discovery, and present a topic’s breadth and depth. WebExhibits, which was among the first online museums, delivers interactive information, virtual experiments, and hands-on activities to the public. While large, multidisciplinary exhibits on topics like “Color Vision and Art” or “Calendars Through the Ages” require teams of scholars, user interface experts, professional writers and editors

  5. Homology in Electromagnetic Boundary Value Problems

    Directory of Open Access Journals (Sweden)

    Pellikka Matti

    2010-01-01

    Full Text Available We discuss how homology computation can be exploited in computational electromagnetism. We represent various cellular mesh reduction techniques, which enable the computation of generators of homology spaces in an acceptable time. Furthermore, we show how the generators can be used for setting up and analysis of an electromagnetic boundary value problem. The aim is to provide a rationale for homology computation in electromagnetic modeling software.

  6. Mobile exhibition in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1960-04-15

    Since January this year, a mobile atomic energy exhibition has been touring the principal cities of Mexico. In organizing this exhibition, the National Nuclear Energy Commission of Mexico was assisted by the International Atomic Energy Agency which has placed its second mobile radioisotope laboratory at the disposal of the Mexican authorities. In many States of the Republic, the visit of the mobile laboratory has given a powerful impetus to atomic training and research. Universities have made use of the laboratory for the training of young scientists in the basic isotope techniques. As a sequel to the work initiated with its aid, some universities are planning to start regular training courses in this field. The laboratory, which is a gift to the Agency from the United States, has been put to its first assignment in Mexico. It will shortly be sent to Argentina for a period of six months for use in training courses. IAEA's first mobile radioisotope unit, also donated by the United States, has been used for training purposes in Austria, the Federal Republic of Germany, Greece and Yugoslavia, and has now been sent to the Far East

  7. Mobile exhibition in Mexico

    International Nuclear Information System (INIS)

    1960-01-01

    Since January this year, a mobile atomic energy exhibition has been touring the principal cities of Mexico. In organizing this exhibition, the National Nuclear Energy Commission of Mexico was assisted by the International Atomic Energy Agency which has placed its second mobile radioisotope laboratory at the disposal of the Mexican authorities. In many States of the Republic, the visit of the mobile laboratory has given a powerful impetus to atomic training and research. Universities have made use of the laboratory for the training of young scientists in the basic isotope techniques. As a sequel to the work initiated with its aid, some universities are planning to start regular training courses in this field. The laboratory, which is a gift to the Agency from the United States, has been put to its first assignment in Mexico. It will shortly be sent to Argentina for a period of six months for use in training courses. IAEA's first mobile radioisotope unit, also donated by the United States, has been used for training purposes in Austria, the Federal Republic of Germany, Greece and Yugoslavia, and has now been sent to the Far East

  8. Anniversary Exhibition. Nechvolodov.

    Directory of Open Access Journals (Sweden)

    - -

    2006-03-01

    Full Text Available On the 10th of August, 2005 in Tartu (the second biggest educational and cultural city in Estonia Stanislav Nechvolodov's exhibition was opened to show the 5-year cycle of his work, traditional for the author and his admirers. At the opening ceremony Nechvolodov said that the exhibition was the last one and appointed on his 70th anniversary.The architectural and building society in Irkutsk remembers Stanislav Nechvolodov as an architect working on dwelling and civil buildings in 1960-70s. Below are some extracts from the Estonian press.«Postimees» newspaper, December 1993. The interview «Expressionistic naturalist, conservative Nechvolodov» by journalist Eric Linnumyagi. He asks about all the details and describes the troubles experienced by Nechvolodov during the perestroika period in Estonia, for example: the Tartu University refused to install the sculpture of Socrat, the art school refused to engage him as an instructor, the sculpture of Socrat moved to Vrotzlav, Poland, and Nechvolodov moved to Poland to read lectures there.«Tartu» newspaper, November 2000. Mats Oun, artist, says in the article «Nechvolodov: a man of Renaissance»: «Nechvolodov works in Estonia, his works are placed in many local and foreign museums. Regardless some insignificant faults, he deserves a high estimation, and his manysided open exhibition can be an example for other artists. He is a man of Renaissance».

  9. Homotopic Chain Maps Have Equal s-Homology and d-Homology

    Directory of Open Access Journals (Sweden)

    M. Z. Kazemi-Baneh

    2016-01-01

    Full Text Available The homotopy of chain maps on preabelian categories is investigated and the equality of standard homologies and d-homologies of homotopic chain maps is established. As a special case, if X and Y are the same homotopy type, then their nth d-homology R-modules are isomorphic, and if X is a contractible space, then its nth d-homology R-modules for n≠0 are trivial.

  10. Relative K-homology and normal operators

    DEFF Research Database (Denmark)

    Manuilov, Vladimir; Thomsen, Klaus

    2009-01-01

    -term exact sequence which generalizes the excision six-term exact sequence in the first variable of KK-theory. Subsequently we investigate the relative K-homology which arises from the group of relative extensions by specializing to abelian $C^*$-algebras. It turns out that this relative K-homology carries...

  11. Lectures on homology with internal symmetries

    International Nuclear Information System (INIS)

    Solovyov, Yu.

    1993-09-01

    Homology with internal symmetries is a natural generalization of cyclic homology introduced, independently, by Connes and Tsygan, which has turned out to be a very useful tool in a number of problems of algebra, geometry topology, analysis and mathematical physics. It suffices to say cycling homology and cohomology are successfully applied in the index theory of elliptic operators on foliations, in the description of the homotopy type of pseudoisotopy spaces, in the theory of characteristic classes in algebraic K-theory. They are also applied in noncommutative differential geometry and in the cohomology of Lie algebras, the branches of mathematics which brought them to life in the first place. Essentially, we consider dihedral homology, which was successfully applied for the description of the homology type of groups of homeomorphisms and diffeomorphisms of simply connected manifolds. (author). 27 refs

  12. Slow Replication Fork Velocity of Homologous Recombination-Defective Cells Results from Endogenous Oxidative Stress

    Science.gov (United States)

    Magdalou, Indiana; Machon, Christelle; Dardillac, Elodie; Técher, Hervé; Guitton, Jérôme; Debatisse, Michelle; Lopez, Bernard S.

    2016-01-01

    Replications forks are routinely hindered by different endogenous stresses. Because homologous recombination plays a pivotal role in the reactivation of arrested replication forks, defects in homologous recombination reveal the initial endogenous stress(es). Homologous recombination-defective cells consistently exhibit a spontaneously reduced replication speed, leading to mitotic extra centrosomes. Here, we identify oxidative stress as a major endogenous source of replication speed deceleration in homologous recombination-defective cells. The treatment of homologous recombination-defective cells with the antioxidant N-acetyl-cysteine or the maintenance of the cells at low O2 levels (3%) rescues both the replication fork speed, as monitored by single-molecule analysis (molecular combing), and the associated mitotic extra centrosome frequency. Reciprocally, the exposure of wild-type cells to H2O2 reduces the replication fork speed and generates mitotic extra centrosomes. Supplying deoxynucleotide precursors to H2O2-exposed cells rescued the replication speed. Remarkably, treatment with N-acetyl-cysteine strongly expanded the nucleotide pool, accounting for the replication speed rescue. Remarkably, homologous recombination-defective cells exhibit a high level of endogenous reactive oxygen species. Consistently, homologous recombination-defective cells accumulate spontaneous γH2AX or XRCC1 foci that are abolished by treatment with N-acetyl-cysteine or maintenance at 3% O2. Finally, oxidative stress stimulated homologous recombination, which is suppressed by supplying deoxynucleotide precursors. Therefore, the cellular redox status strongly impacts genome duplication and transmission. Oxidative stress should generate replication stress through different mechanisms, including DNA damage and nucleotide pool imbalance. These data highlight the intricacy of endogenous replication and oxidative stresses, which are both evoked during tumorigenesis and senescence initiation

  13. Slow Replication Fork Velocity of Homologous Recombination-Defective Cells Results from Endogenous Oxidative Stress.

    Directory of Open Access Journals (Sweden)

    Therese Wilhelm

    2016-05-01

    Full Text Available Replications forks are routinely hindered by different endogenous stresses. Because homologous recombination plays a pivotal role in the reactivation of arrested replication forks, defects in homologous recombination reveal the initial endogenous stress(es. Homologous recombination-defective cells consistently exhibit a spontaneously reduced replication speed, leading to mitotic extra centrosomes. Here, we identify oxidative stress as a major endogenous source of replication speed deceleration in homologous recombination-defective cells. The treatment of homologous recombination-defective cells with the antioxidant N-acetyl-cysteine or the maintenance of the cells at low O2 levels (3% rescues both the replication fork speed, as monitored by single-molecule analysis (molecular combing, and the associated mitotic extra centrosome frequency. Reciprocally, the exposure of wild-type cells to H2O2 reduces the replication fork speed and generates mitotic extra centrosomes. Supplying deoxynucleotide precursors to H2O2-exposed cells rescued the replication speed. Remarkably, treatment with N-acetyl-cysteine strongly expanded the nucleotide pool, accounting for the replication speed rescue. Remarkably, homologous recombination-defective cells exhibit a high level of endogenous reactive oxygen species. Consistently, homologous recombination-defective cells accumulate spontaneous γH2AX or XRCC1 foci that are abolished by treatment with N-acetyl-cysteine or maintenance at 3% O2. Finally, oxidative stress stimulated homologous recombination, which is suppressed by supplying deoxynucleotide precursors. Therefore, the cellular redox status strongly impacts genome duplication and transmission. Oxidative stress should generate replication stress through different mechanisms, including DNA damage and nucleotide pool imbalance. These data highlight the intricacy of endogenous replication and oxidative stresses, which are both evoked during tumorigenesis and

  14. Slow Replication Fork Velocity of Homologous Recombination-Defective Cells Results from Endogenous Oxidative Stress.

    Science.gov (United States)

    Wilhelm, Therese; Ragu, Sandrine; Magdalou, Indiana; Machon, Christelle; Dardillac, Elodie; Técher, Hervé; Guitton, Jérôme; Debatisse, Michelle; Lopez, Bernard S

    2016-05-01

    Replications forks are routinely hindered by different endogenous stresses. Because homologous recombination plays a pivotal role in the reactivation of arrested replication forks, defects in homologous recombination reveal the initial endogenous stress(es). Homologous recombination-defective cells consistently exhibit a spontaneously reduced replication speed, leading to mitotic extra centrosomes. Here, we identify oxidative stress as a major endogenous source of replication speed deceleration in homologous recombination-defective cells. The treatment of homologous recombination-defective cells with the antioxidant N-acetyl-cysteine or the maintenance of the cells at low O2 levels (3%) rescues both the replication fork speed, as monitored by single-molecule analysis (molecular combing), and the associated mitotic extra centrosome frequency. Reciprocally, the exposure of wild-type cells to H2O2 reduces the replication fork speed and generates mitotic extra centrosomes. Supplying deoxynucleotide precursors to H2O2-exposed cells rescued the replication speed. Remarkably, treatment with N-acetyl-cysteine strongly expanded the nucleotide pool, accounting for the replication speed rescue. Remarkably, homologous recombination-defective cells exhibit a high level of endogenous reactive oxygen species. Consistently, homologous recombination-defective cells accumulate spontaneous γH2AX or XRCC1 foci that are abolished by treatment with N-acetyl-cysteine or maintenance at 3% O2. Finally, oxidative stress stimulated homologous recombination, which is suppressed by supplying deoxynucleotide precursors. Therefore, the cellular redox status strongly impacts genome duplication and transmission. Oxidative stress should generate replication stress through different mechanisms, including DNA damage and nucleotide pool imbalance. These data highlight the intricacy of endogenous replication and oxidative stresses, which are both evoked during tumorigenesis and senescence initiation

  15. cDNAs encoding [D-Ala2]deltorphin precursors from skin of Phyllomedusa bicolor also contain genetic information for three dermorphin-related opioid peptides.

    OpenAIRE

    Richter, K; Egger, R; Negri, L; Corsi, R; Severini, C; Kreil, G

    1990-01-01

    We present the structure of four precursors for [D-Ala2]deltorphins I and II as deduced from cDNAs cloned from skin of the frog Phyllomedusa bicolor. These contain the genetic information for one copy of [D-Ala2]deltorphin II and zero, one, or three copies of [D-Ala2]deltorphin I. In each case, the D-alanine of the end product is encoded by a normal GCG codon for L-alanine. In addition, the existence of three peptides related to dermorphin was predicted from the amino acid sequence of the pre...

  16. Preserved irradiated homologous cartilage for orbital reconstruction

    International Nuclear Information System (INIS)

    Linberg, J.V.; Anderson, R.L.; Edwards, J.J.; Panje, W.R.; Bardach, J.

    1980-01-01

    Human costal cartilage is an excellent implant material for orbital and periorbital reconstruction because of its light weight, strength, homogeneous consistency and the ease with which it can be carved. Its use has been limited by the necessity of a separate surgical procedure to obtain the material. Preserved irradiated homologous cartilage has been shown to have almost all the autogenous cartilage and is convenient to use. Preserved irradiated homologous cartilage transplants do not elicit rejection reactions, resist infection and rarely undergo absorption

  17. Dualities in persistent (co)homology

    International Nuclear Information System (INIS)

    De Silva, Vin; Morozov, Dmitriy; Vejdemo-Johansson, Mikael

    2011-01-01

    We consider sequences of absolute and relative homology and cohomology groups that arise naturally for a filtered cell complex. We establish algebraic relationships between their persistence modules, and show that they contain equivalent information. We explain how one can use the existing algorithm for persistent homology to process any of the four modules, and relate it to a recently introduced persistent cohomology algorithm. We present experimental evidence for the practical efficiency of the latter algorithm

  18. Sequence of cDNAs for mammalian H2A. Z, an evolutionarily diverged but highly conserved basal histone H2A isoprotein species

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, C L; Bonner, W M

    1988-02-11

    The nucleotide sequences of cDNAs for the evolutionarily diverged but highly conserved basal H2A isoprotein, H2A.Z, have been determined for the rat, cow, and human. As a basal histone, H2A.Z is synthesized throughout the cell cycle at a constant rate, unlinked to DNA replication, and at a much lower rate in quiescent cells. Each of the cDNA isolates encodes the entire H2A.Z polypeptide. The human isolate is about 1.0 kilobases long. It contains a coding region of 387 nucleotides flanked by 106 nucleotides of 5'UTR and 376 nucleotides of 3'UTR, which contains a polyadenylation signal followed by a poly A tail. The bovine and rat cDNAs have 97 and 94% nucleotide positional identity to the human cDNA in the coding region and 98% in the proximal 376 nucleotides of the 3'UTR which includes the polyadenylation signal. A potential stem-forming sequence imbedded in a direct repeat is found centered at 261 nucleotides into the 3'UTR. Each of the cDNA clones could be transcribed and translated in vitro to yield H2A.Z protein. The mammalian H2A.Z cDNA coding sequences are approximately 80% similar to those in chicken and 75% to those in sea urchin.

  19. Exhibition

    CERN Multimedia

    Staff Association

    2014-01-01

    Energie sombre, matière noire J.-J. Dalmais - J. Maréchal Du 11 au 27 novembre 2014, CERN Meyrin, Bâtiment principal A l’image des particules atomiques qui ont tissé des liens pour créer la matière, deux artistes haut bugistes croisent leurs regards et conjuguent leurs expressions singulières pour faire naître une vision commune de l’univers, produit des forces primordiales. Les sculptures de Jean-Jacques Dalmais et les peintures de Jacki Maréchal se rencontrent pour la première fois et se racontent par un enrichissement mutuel la belle histoire de la Vie. Dialogue magique des œuvres en mouvement qui questionnent en écho l’énergie sombre et la matière noire. Cette harmonieuse confluence de jeux de miroir et de résonnance illumine de poésie et de sobriété l’espace expos&...

  20. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Gaïa Manuella Cany Du 10 au 28 avril 2017 CERN Meyrin, Bâtiment principal Oiseau - Manuella Cany. Tableaux abstraits inspirés de vues satellites ou photos prises du ciel. Certains sont à la frontière du figuratif alors que d'autres permettent de laisser libre cours à son imagination. Aux détails infinis, ces tableaux sont faits pour être vus de loin et de près grâce à une attention toute particulière apportée aux effets de matières et aux couleurs le long de volutes tantôt nuancées tantôt contrastées.   Pour plus d’informations : staff.association@cern.ch | Tél: 022 766 37 38

  1. Exhibition

    CERN Document Server

    Staff Association

    2018-01-01

    En dehors des frontières Maxence Piquet Du 2 au 11 mai 2018 | CERN Meyrin, Bâtiment principal Exposition de peinture d'un artiste autodidacte Maxence Piquet (signature artiste M-P), avec différentes techniques (acrylique, huile, fusain, collage...) et sur différents supports. Un art souvent brut et parfois provoquant, avec des touches expressionnistes et cubistes principale origine de son art. Des œuvres souvent vivent et colorées... Cette exposition est la première en dehors d ses frontières Lorraine et a pour but de faire voyager son art au regard du plus grand nombre . Pour plus d’informations et demandes d’accès : staff.association@cern.ch | Tél: 022 766 37 38

  2. Exhibition

    CERN Multimedia

    Staff Association

    2016-01-01

    The Elementary Particles of Painting Alfonso Fratteggiani Bianchi and Ermanno Imbergamo From September 26 to October 7, 2016 CERN Meyrin, Main Building With intentions similar to those of CERN physicists, the artist Alfonso Fratteggiani Bianchi investigates the color pigment, studying its interaction with light and with the support on which it is deposited. He creates monochrome paintings by spreading the color pigment in the pure state on stones, without using glue or any other type of adhesive. With intentions similar to artists, the physicist Ermanno Imbergamo investigates the use of luminescent wavelength shifters, materials commonly used in Particle Physics, for art. He creates other monochrome artworks, which disclose further aspects of interaction among light, color pigments and support. For more information: staff.association@cern.ch | Tel: 022 767 28 19

  3. Exhibition

    CERN Multimedia

    Staff Association

    2016-01-01

    COLORATION Sandra Duchêne From September 5 to 16, 2016 CERN Meyrin, Main Building La recherche de l’Universel. Après tout ! C’est de l’Amour ! What else to say ? …La couleur, l’ENERGIE de la vie…

  4. Exhibition

    CERN Multimedia

    Staff Association

    2014-01-01

      Parallels vision Astronomical subjects which evoke extrasensory kinetic visions Alberto Di Fabio From 8 to 10 October, CERN Meyrin, Main Building In the framework of Italy@cern, the Staff Association presents Alberto Di Fabio. Di Fabio’s work is inspired by the fundamental laws of the physical world, as well as organic elements and their interrelation. His paintings and works on paper merge the worlds of art and science, depicting natural forms and biological structures in vivid colour and imaginative detail. For all additional information: staff.association@cern.ch | Tel: 022 767 28 19

  5. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Le Point Isabelle Gailland Du 20 février au 3 mars 2017 CERN Meyrin, Bâtiment principal La Diagonale - Isabelle Gailland. Au départ, un toujours même point minuscule posé au centre de ce que la toile est un espace. Une réplique d'autres points, condensés, alignés, isolés, disséminés construiront dans leur extension, la ligne. Ces lignes, croisées, courbées, déviées, prolongées, seront la structure contenant et séparant la matière des couleurs. La rotation de chaque toile en cours d'exécution va offrir un accès illimité à la non-forme et à la forme. Le point final sera l'ouverture sur différents points de vue de ce que le point et la ligne sont devenus une représentation pour l'œil et l'im...

  6. Exhibition

    CERN Multimedia

    Staff Association

    2018-01-01

    La danse mécanique Daria Grigoryeva Du 22 mai au 1er juin 2018 | CERN Meyrin, Bâtiment principal La danse mécanique est une métaphore large. La mécanique établit les règles et les limites, les frontières dans lesquelles la vie et la créativité peuvent se développer. La musique est « mathématique », une poupée mécanique se tourne toujours dans la même direction, selon les règles prescrites par la nature les fleurs fleurissent au printemps. Même s'ils ne le voulaient pas. La participation à la "danse mécanique" est prédéterminée et inévitable. Il ne reste plus qu'à comprendre comment le faire "magnifiquement". En tout, il y a une signification cachée et un...

  7. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Still Life Jérémy Bajulaz Du 25 septembre au 6 octobre 2017 CERN Meyrin, Main Building (Aubergine - Jérémy Bajulaz) Né en 1991 en Haute-Savoie, France. Diplômé de l'Ecole Emile Cohl à Lyon, Jérémy Bajulaz intègre en 2014 le programme d'artiste en résidence au Centre Genevois de Gravure Contemporaine. C'est là que son travail prendra corps, autour de la lumière et de ses vibrations aux travers de sujets comme le portrait et la nature morte, dans le souci de l'observation; le regard prenant une place importante dans le processus créatif. Lauréat 2017 du VII Premio AAAC, son travail a été présenté dans de nombreuses expositions collectives, en 2015 au Bâtiment d’Art Contemporain de Genève, en 2016 au 89e Salon de Lyon et du ...

  8. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Œuvres recentes Fabienne Wyler Du 6 au 17 février 2017 CERN Meyrin, Bâtiment principal L'escalier du diable B - aquarelle, encre de Chine XLV - Fabienne Wyler. En relation avec certains procédés d’écriture contemporaine (par ex. Webern ou certaines musiques conçues par ordinateur), les compositions picturales de Fabienne Wyler s’élaborent à partir de « modules » (groupes de quadrangles) qu’elle reproduit en leur faisant subir toutes sortes de transformations et de déplacements : étirements, renversements, rotations, effet miroir, transpositions, déphasages, superpositions, etc., et ceci à toutes les échelles. Au fil des œuvres sont apparues des séries intitulées, Bifurcations, Intermittences, Attracteurs étranges, Polyrythmies. Ces titres ont un lien &e...

  9. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Les vibrantes Patrick Robbe-Grillet Du 30 octobre au 10 novembre 2017 CERN Meyrin, Main Building Patrick Robbe-Grillet - Feux d'artifices Qui est Patrick Robbe-Grillet ? Artiste Franco-Suisse, né en 1968 à Genève. En recherche du sentiment de paix, autodidacte, après un séjour en Chine en 2000, puis au Japon en 2002, suivi d’un long questionnement, il trouve sa voie dans la peinture, élément libérateur de sa créativité et expression de sa sensibilité à fleur de peau. « La Chine m’a enseigné les courbes, les nuances. Le Japon, la ligne droite, la rigueur. » Vous avez su rendre visible l'invisible ! - commentaire de Monsieur Fawaz Gruosi Pour plus d’informations et demandes d’accès : staff.association@cern.ch | Tél : 022 766 37 38

  10. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    La couleur des jours oriSio Du 2 au 12 mai 2017 CERN Meyrin, Bâtiment principal oriSio - Motus Suite à un fort intérêt pour la Chine et une curiosité pour un médium très ancien, la laque ! Je réinterprète cet art à travers un style abstrait. Je présente ici des laques sur aluminium, travaillés au plasma et ensuite colorés à l’aide de pigments pour l’essentiel. Mes œuvres je les veux brutes, déchirées, évanescentes, gondolées, voire trouées mais avec une belle approche de profondeur de la couleur.   Pour plus d’informations : staff.association@cern.ch | Tél: 022 766 37 38

  11. Exhibition

    CERN Multimedia

    Staff Association

    2011-01-01

    Jan Hladky, physicien de l'Institut de Physique de l'Académie des Sciences de la République tchèque, et membre de la collaboration Alice, expose ses œuvres au Bâtiment principal du 20 avril au 6 mai. Son exposition est dédiée aux victimes du séisme de Sendai. Des copies de ses œuvres seront mises en vente et les sommes récoltées seront versées au profit des victimes.

  12. Exhibition

    CERN Multimedia

    Staff Association

    2016-01-01

    La mosaïque ou quand détruire permet de construire Lauren Decamps Du 28 novembre au 9 décembre 2016 CERN Meyrin, Bâtiment principal Paysage d'Amsterdam - Lauren Decamps On ne doit jamais rien détruire qu'on ne soit sûr de pouvoir remplacer aussi avantageusement " écrivait Plutarque dans ses Œuvres morales du 1er siècle après JC. L'artiste mosaïste Lauren Decamps adhère à cette idée et tente à sa manière de donner une nouvelle vie à ses matériaux en les taillant puis les réassemblant, créant ainsi des œuvres abstraites et figuratives.

  13. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Firmament des toiles Joëlle Lalagüe Du 6 au 16 juin 2017 CERN Meyrin, Bâtiment principal Phylaë Voyage - Joëlle Lalagüe. Each picture is an invitation for a cosmic trip. This is a whispering of soul, which comes from origins. A symphony of the world, some notes of love, a harmony for us to fly to infinity. Pour plus d’informations et demandes d'accès : staff.association@cern.ch | Tél: 022 766 37 38

  14. Exhibition

    CERN Multimedia

    Staff Association

    2018-01-01

    Univers Du 9 au 20 avril 2018 | CERN Meyrin, Bâtiment principal Stéphanie Cousin Obsédée par les rêves, les mondes surréalistes et insolites, je m’empare de formes provenant des mes propres travaux photographiques ou d’images que je modifie et mixe. Je fais évoluer mes univers oniriques de femmes-animaux ainsi que mes espaces et natures imaginaires. Avec ma démarche artistique, je cherche à mettre en images nos rêves et nos cauchemars, l’irréel et le surréel, le mystique et les affres de notre inconscient. Je cherche à représenter tout ce qui sommeille au plus profond de nous-même à l’aide de symboles, parfois en utilisant des images de cultures ancestrales. Photographie-collage, je cherche à ajouter quelques notes à la définition de la photographie du 21iè...

  15. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Harmonie Nathalie Lenoir Du 4 au 15 septembre 2017 CERN Meyrin, Bâtiment principal Peindre est un langage. Le tracé du pinceau sur le lin en est l'expression. A qui appartient un tableau en définitive ? A celui qui l'a peint ? A celui qui le regarde ? A celui qui l'emporte ? La peinture est une émotion partagée... Laissez-vous projeter de l'autre côté de la toile, prenez un moment pour rêver, en harmonie avec les éléments, parce-que la peinture parle à votre âme… Pour plus d’informations et demandes d’accès : staff.association@cern.ch | Tél : 022 766 37 38

  16. Exhibition

    CERN Multimedia

    Staff Association

    2018-01-01

    Cosmos KOLI Du 15 au 26 janvier 2018 CERN Meyrin, Main Building (Nébuleuse d'Orion- KOLI) KOLI, Artiste confirmé, diplômé de l’Académie de Beaux Arts de Tirana, depuis 26 ans en Suisse, où il a participé à maintes expositions collectives et organisé 10 expositions privées avec  beaucoup de succès, s’exprime actuellement dans un bonheur de couleur et de matières qui côtoient des hautes sphères… le cosmos ! Gagnant d’un premier prix lors d’une exposition collective organisée par le consulat Italien, il s’est installé au bord du lac dans le canton de Vaud où il vit depuis maintenant déjà 13 ans. www.kolicreation.com Pour plus d’informations et demandes d’accès : staff.association@cern.ch | T&eacut...

  17. Exhibition at the AAA library

    DEFF Research Database (Denmark)

    2013-01-01

    Sonnesgade 11 The exhibition at the AAA library presents selected work produced by students prior to the exhibition of installations in project and praxis constructing an archive at Sonnesgade 11. The exhibition at Sonnesgade 11 was the culmination of collaboration with SLETH architects and studio...

  18. Homological methods, representation theory, and cluster algebras

    CERN Document Server

    Trepode, Sonia

    2018-01-01

    This text presents six mini-courses, all devoted to interactions between representation theory of algebras, homological algebra, and the new ever-expanding theory of cluster algebras. The interplay between the topics discussed in this text will continue to grow and this collection of courses stands as a partial testimony to this new development. The courses are useful for any mathematician who would like to learn more about this rapidly developing field; the primary aim is to engage graduate students and young researchers. Prerequisites include knowledge of some noncommutative algebra or homological algebra. Homological algebra has always been considered as one of the main tools in the study of finite-dimensional algebras. The strong relationship with cluster algebras is more recent and has quickly established itself as one of the important highlights of today’s mathematical landscape. This connection has been fruitful to both areas—representation theory provides a categorification of cluster algebras, wh...

  19. A homology theory for smale spaces

    CERN Document Server

    Putnam, Ian F

    2014-01-01

    The author develops a homology theory for Smale spaces, which include the basics sets for an Axiom A diffeomorphism. It is based on two ingredients. The first is an improved version of Bowen's result that every such system is the image of a shift of finite type under a finite-to-one factor map. The second is Krieger's dimension group invariant for shifts of finite type. He proves a Lefschetz formula which relates the number of periodic points of the system for a given period to trace data from the action of the dynamics on the homology groups. The existence of such a theory was proposed by Bowen in the 1970s.

  20. Characterization of cDNAs encoding human leukosialin and localization of the leukosialin gene to chromosome 16

    International Nuclear Information System (INIS)

    Pallant, A.; Eskenazi, A.; Frelinger, J.G.; Mattei, M.G.; Fournier, R.E.K.; Carlsson, S.R.; Fukuda, M.

    1989-01-01

    The authors describe the isolation and characterization of cDNA clones encoding human leukosialin, a major sialoglycoprotein of human leukocytes. Leukosialin is very closely related or identical to the sialophorin molecule, which is involved in T-cell proliferation and whose expression is altered in Wiskott-Aldrich syndrome (WAS), an X-chromosome-linked immunodeficiency disease. Using a rabbit antiserum to leukosialin, a cDNA clone was isolated from a λgt11 cDNA library constructed from human peripheral blood cells. The λgt11 clone was used to isolate longer cDNA clones that correspond to the entire coding sequence of leukosialin. DNA sequence analysis reveals three domains in the predicted mature protein. The extracellular domain is enriched for Ser, Thr, and Pro and contains four contiguous 18-amino acid repeats. The transmembrane and intracellular domains of the human leukosialin molecule are highly homologous to the rat W3/13 molecule. RNA gel blot analysis reveals two polyadenylylated species of 2.3 and 8 kilobases. Southern blot analysis suggests that human leukosialin is a single-copy gene. Analysis of monochromosomal cell hybrids indicates that the leukosialin gene is not X chromosome linked and in situ hybridization shows leukosialin is located on chromosome 16. These findings demonstrate that the primary mutation in WAS is not a defect in the structural gene for leukosialin

  1. Differential expression of two flavonoid 3'-hydroxylase cDNAs involved in biosynthesis of anthocyanin pigments and 3-deoxyanthocyanidin phytoalexins in sorghum.

    Science.gov (United States)

    Shih, Chun-Hat; Chu, Ivan K; Yip, Wing Kin; Lo, Clive

    2006-10-01

    Three unique sorghum flavonoid 3'-hydroxylase (F3'H) cDNAs (SbF3'H1, SbF3'H2 and SbF3'H3) were discovered through bioinformatics analysis. Their encoded proteins showed >60% identity to the Arabidopsis TT7 (F3'H) protein. Overexpression of SbF3'H1 or SbF3'H2 restored the ability of tt7 mutants to produce 3'-hydroxylated flavonoids, establishing their roles as functional F3'H enzymes. In sorghum mesocotyls, SbF3'H1 expression was involved in light-specific anthocyanin accumulation while SbF3'H2 expression was involved in pathogen-specific 3-deoxyanthocyanidin synthesis. No SbF3'H3 expression was detected in all tissues examined. The sorghum mesocotyls represent a good system for investigation of differential regulation of F3'H genes/alleles responding to different external stimuli.

  2. cDNAs encoding [D-Ala2]deltorphin precursors from skin of Phyllomedusa bicolor also contain genetic information for three dermorphin-related opioid peptides.

    Science.gov (United States)

    Richter, K; Egger, R; Negri, L; Corsi, R; Severini, C; Kreil, G

    1990-06-01

    We present the structure of four precursors for [D-Ala2]deltorphins I and II as deduced from cDNAs cloned from skin of the frog Phyllomedusa bicolor. These contain the genetic information for one copy of [D-Ala2]deltorphin II and zero, one, or three copies of [D-Ala2]deltorphin I. In each case, the D-alanine of the end product is encoded by a normal GCG codon for L-alanine. In addition, the existence of three peptides related to dermorphin was predicted from the amino acid sequence of the precursors. These peptides were synthesized with a D-alanine in position 2 and their pharmacological properties were tested. Two of them, [Lys7]dermorphin-OH and [Trp4,Asn7]dermorphin-OH, were found to have roughly the same affinity and selectivity for mu-type opioid receptors as dermorphin.

  3. Identities among actin-encoding cDNAs of the Nile tilapia (Oreochromis niloticus and other eukaryote species revealed by nucleotide and amino acid sequence analyses

    Directory of Open Access Journals (Sweden)

    Andréia B. Poletto

    2008-01-01

    Full Text Available Actin-encoding cDNAs of Nile tilapia (Oreochromis niloticus were isolated by RT-PCR using total RNA samples of different tissues and further characterized by nucleotide sequencing and in silico amino acid (aa sequence analysis. Comparisons among the actin gene sequences of O. niloticus and those of other species evidenced that the isolated genes present a high similarity to other fish and other vertebrate actin genes. The highest nucleotide resemblance was observed between O. niloticus and O. mossambicus a-actin and b-actin genes. Analysis of the predicted aa sequences revealed two distinct types of cytoplasmic actins, one cardiac muscle actin type and one skeletal muscle actin type that were expressed in different tissues of Nile tilapia. The evolutionary relationships between the Nile tilapia actin genes and diverse other organisms is discussed.

  4. Homology and cohomology of Rees semigroup algebras

    DEFF Research Database (Denmark)

    Grønbæk, Niels; Gourdeau, Frédéric; White, Michael C.

    2011-01-01

    Let S by a Rees semigroup, and let 1¹(S) be its convolution semigroup algebra. Using Morita equivalence we show that bounded Hochschild homology and cohomology of l¹(S) is isomorphic to those of the underlying discrete group algebra....

  5. Induction of homologous recombination in Saccharomyces cerevisiae.

    Science.gov (United States)

    Simon, J R; Moore, P D

    1988-09-01

    We have investigated the effects of UV irradiation of Saccharomyces cerevisiae in order to distinguish whether UV-induced recombination results from the induction of enzymes required for homologous recombination, or the production of substrate sites for recombination containing regions of DNA damage. We utilized split-dose experiments to investigate the induction of proteins required for survival, gene conversion, and mutation in a diploid strain of S. cerevisiae. We demonstrate that inducing doses of UV irradiation followed by a 6 h period of incubation render the cells resistant to challenge doses of UV irradiation. The effects of inducing and challenge doses of UV irradiation upon interchromosomal gene conversion and mutation are strictly additive. Using the yeast URA3 gene cloned in non-replicating single- and double-stranded plasmid vectors that integrate into chromosomal genes upon transformation, we show that UV irradiation of haploid yeast cells and homologous plasmid DNA sequences each stimulate homologous recombination approximately two-fold, and that these effects are additive. Non-specific DNA damage has little effect on the stimulation of homologous recombination, as shown by studies in which UV-irradiated heterologous DNA was included in transformation/recombination experiments. We further demonstrate that the effect of competing single- and double-stranded heterologous DNA sequences differs in UV-irradiated and unirradiated cells, suggesting an induction of recombinational machinery in UV-irradiated S. cerevisiae cells.

  6. Threading homology through algebra selected patterns

    CERN Document Server

    Boffi, Giandomenico

    2006-01-01

    Aimed at graduate students and researchers in mathematics, this book takes homological themes, such as Koszul complexes and their generalizations, and shows how these can be used to clarify certain problems in selected parts of algebra, as well as their success in solving a number of them.

  7. Cell biology of homologous recombination in yeast

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine Valerie; Rothstein, Rodney; Lisby, Michael

    2011-01-01

    Homologous recombination is an important pathway for error-free repair of DNA lesions, such as single- and double-strand breaks, and for rescue of collapsed replication forks. Here, we describe protocols for live cell imaging of single-lesion recombination events in the yeast Saccharomyces...

  8. The World of Virtual Exhibitions

    Directory of Open Access Journals (Sweden)

    Irena Eiselt

    2013-09-01

    Full Text Available EXTENDED ABSTRACTSpecial collections of the National and University Library (NUK hide a lot of items of precious value. The Slovenian cultural heritage is stored on paper or on other media as a part of the library’s Manuscripts, Incunabula and Rare Books Collection, Old Prints Collection, Maps and Pictorial Collection, Music Collection, Ephemera Collection, Serials Collection, and Slovenian Diaspora Publications Collection. Only a small part of the treasures is temporary revealed to the public on special exhibitions. The idea of virtual exhibitions of library treasures was born in 2005. The library aimed to exhibit precious items of special collections of high historical or artistic value. In 2008 the first two virtual exhibitions were created in-house offering access to the rich collections of old postcards of Ljubljana at the beginning of 20th century kept in the Maps and Pictorial Collection of NUK. They were soon followed by other virtual exhibitions. At the beginning they were organised in the same way as physical exhibitions, afterwards different programs were used for creation of special effects (for ex. 3D wall. About two years ago it was decided that the creation of virtual exhibitions will be simplified. Files of digitised and borndigital library materials in jpg format are imported to MS PowerPoint 2010. Each jpg file is now formatted by adding a frame, a description … to the slides which are saved as jpg files. The last step is the import of jpg files into Cooliris application used for NUK web exhibitions. In the paper the virtual exhibition design and creation, the technical point of view and criteria for the selection of exhibition content are explained following the example of the virtual exhibitions the Old Postcards of Ljubljana, Photo Ateliers in Slovenia, a collection of photographs Four Seasons by Fran Krašovec and photos of Post-Earthquake Ljubljana in 1895.

  9. Polar representation of centrifugal pump homologous curves

    International Nuclear Information System (INIS)

    Veloso, Marcelo Antonio; Mattos, Joao Roberto Loureiro de

    2008-01-01

    Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic parameters: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. Any one of these quantities can be expressed as a function of any two others. The curves showing the relationships between these four variables are called the pump characteristic curves, also referred to as four-quadrant curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, the four-quadrant configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the polar form appears as the simplest way to represent the homologous curves. In the polar method, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a

  10. Parametric representation of centrifugal pump homologous curves

    International Nuclear Information System (INIS)

    Veloso, Marcelo A.; Mattos, Joao R.L. de

    2015-01-01

    Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic quantities: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. The curves showing the relationships between these four variables are called the pump characteristic curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, this configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the parametric form appears as the simplest way to deal with the homologous curves. In this approach, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a pressurized water reactor (PWR) are transformed to the parametric form. (author)

  11. On discrete symmetries and torsion homology in F-theory

    Energy Technology Data Exchange (ETDEWEB)

    Mayrhofer, Christoph [Arnold-Sommerfeld-Center, Ludwig-Maximilians-Universität München,München (Germany); Palti, Eran; Till, Oskar; Weigand, Timo [Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg,Heidelberg (Germany)

    2015-06-04

    We study the relation between discrete gauge symmetries in F-theory compactifications and torsion homology on the associated Calabi-Yau manifold. Focusing on the simplest example of a ℤ{sub 2} symmetry, we show that there are two physically distinct ways that such a discrete gauge symmetry can arise. First, compactifications of M-Theory on Calabi-Yau threefolds which support a genus-one fibration with a bi-section are known to be dual to six-dimensional F-theory vacua with a ℤ{sub 2} gauge symmetry. We show that the resulting five-dimensional theories do not have a ℤ{sub 2} symmetry but that the latter emerges only in the F-theory decompactification limit. Accordingly the genus-one fibred Calabi-Yau manifolds do not exhibit torsion in homology. Associated to the bi-section fibration is a Jacobian fibration which does support a section. Compactifying on these related but distinct varieties does lead to a ℤ{sub 2} symmetry in five dimensions and, accordingly, we find explicitly an associated torsion cycle. We identify the expected particle and membrane system of the discrete symmetry in terms of wrapped M2 and M5 branes and present a field-theory description of the physics for both cases in terms of circle reductions of six-dimensional theories. Our results and methods generalise straightforwardly to larger discrete symmetries and to four-dimensional compactifications.

  12. Development and homology of the incisor teeth in the rabbit

    International Nuclear Information System (INIS)

    Muylle, S.; Simoens, P.; Lauwers, H.

    1996-01-01

    The morphology and development of the incisors were investigated stercomicroscopically, radiographically and by means of serial histologic sections in fetal, juvenile and adult New Zealand White rabbits. A vestigial and a major incisor develop on both sides of the upper and of the lower jaw, while a diphyodont minor incisor is located caudal to the major incisor on both sides of the upper jaw. The present study describes a unique case of incisor polyodontia in an adult wild rabbit, that exhibited all the characteristics of a typical atavistic dentition. From these observations it was deduced that the vestigial and the major incisors in the rabbit are monophyodont and correspond to the first and second incisors respectively, while the minor diphyodont incisor in the upper jaw is homologous with the third incisor

  13. Evidence of accelerated evolution and ectodermal-specific expression of presumptive BDS toxin cDNAs from Anemonia viridis.

    Science.gov (United States)

    Nicosia, Aldo; Maggio, Teresa; Mazzola, Salvatore; Cuttitta, Angela

    2013-10-30

    Anemonia viridis is a widespread and extensively studied Mediterranean species of sea anemone from which a large number of polypeptide toxins, such as blood depressing substances (BDS) peptides, have been isolated. The first members of this class, BDS-1 and BDS-2, are polypeptides belonging to the β-defensin fold family and were initially described for their antihypertensive and antiviral activities. BDS-1 and BDS-2 are 43 amino acid peptides characterised by three disulfide bonds that act as neurotoxins affecting Kv3.1, Kv3.2 and Kv3.4 channel gating kinetics. In addition, BDS-1 inactivates the Nav1.7 and Nav1.3 channels. The development of a large dataset of A. viridis expressed sequence tags (ESTs) and the identification of 13 putative BDS-like cDNA sequences has attracted interest, especially as scientific and diagnostic tools. A comparison of BDS cDNA sequences showed that the untranslated regions are more conserved than the protein-coding regions. Moreover, the KA/KS ratios calculated for all pairwise comparisons showed values greater than 1, suggesting mechanisms of accelerated evolution. The structures of the BDS homologs were predicted by molecular modelling. All toxins possess similar 3D structures that consist of a triple-stranded antiparallel β-sheet and an additional small antiparallel β-sheet located downstream of the cleavage/maturation site; however, the orientation of the triple-stranded β-sheet appears to differ among the toxins. To characterise the spatial expression profile of the putative BDS cDNA sequences, tissue-specific cDNA libraries, enriched for BDS transcripts, were constructed. In addition, the proper amplification of ectodermal or endodermal markers ensured the tissue specificity of each library. Sequencing randomly selected clones from each library revealed ectodermal-specific expression of ten BDS transcripts, while transcripts of BDS-8, BDS-13, BDS-14 and BDS-15 failed to be retrieved, likely due to under-representation in our

  14. Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis

    Directory of Open Access Journals (Sweden)

    Aldo Nicosia

    2013-10-01

    Full Text Available Anemonia viridis is a widespread and extensively studied Mediterranean species of sea anemone from which a large number of polypeptide toxins, such as blood depressing substances (BDS peptides, have been isolated. The first members of this class, BDS-1 and BDS-2, are polypeptides belonging to the β-defensin fold family and were initially described for their antihypertensive and antiviral activities. BDS-1 and BDS-2 are 43 amino acid peptides characterised by three disulfide bonds that act as neurotoxins affecting Kv3.1, Kv3.2 and Kv3.4 channel gating kinetics. In addition, BDS-1 inactivates the Nav1.7 and Nav1.3 channels. The development of a large dataset of A. viridis expressed sequence tags (ESTs and the identification of 13 putative BDS-like cDNA sequences has attracted interest, especially as scientific and diagnostic tools. A comparison of BDS cDNA sequences showed that the untranslated regions are more conserved than the protein-coding regions. Moreover, the KA/KS ratios calculated for all pairwise comparisons showed values greater than 1, suggesting mechanisms of accelerated evolution. The structures of the BDS homologs were predicted by molecular modelling. All toxins possess similar 3D structures that consist of a triple-stranded antiparallel β-sheet and an additional small antiparallel β-sheet located downstream of the cleavage/maturation site; however, the orientation of the triple-stranded β-sheet appears to differ among the toxins. To characterise the spatial expression profile of the putative BDS cDNA sequences, tissue-specific cDNA libraries, enriched for BDS transcripts, were constructed. In addition, the proper amplification of ectodermal or endodermal markers ensured the tissue specificity of each library. Sequencing randomly selected clones from each library revealed ectodermal-specific expression of ten BDS transcripts, while transcripts of BDS-8, BDS-13, BDS-14 and BDS-15 failed to be retrieved, likely due to under

  15. Photowalk Exhibition opens at Microcosm

    CERN Document Server

    Katarina Anthony

    2011-01-01

    The winning photographs from the 2010 Global Particle Physics Photowalk competition will go on display at Microcosm from 11 February to 2 April. The exhibition is part of a global photography event taking place over three continents, with Photowalk exhibitions opening simultaneously at Fermilab in the US, KEK in Japan and here at CERN.   DESY wire chamber - First place people's choice; second place global jury competition. Photographer: Hans-Peter Hildebrandt  If you were one of the 1,300 photography lovers who voted in last year’s Photowalk competition, this exhibition is your chance to see the winning entries in print. The exhibition will take place in the downstairs gallery of Microcosm, overlooking the garden. 15 photographs will be on display, with each of the laboratories that participated in Photowalk represented by their 3 winning entries. Among them will be the “people’s choice” sunburst photo of a particle detector at DESY (Photo 1), and...

  16. Globe exhibit wins international acclaim

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    The Globe’s “Universe of Particles” exhibition has recently received four prestigious awards for its avant-garde design. This external praise is great encouragement for the CERN exhibitions currently on the drawing board.   The Universe of Particles exhibition has won 4 awards for its avant-garde design. Back in 2008, the design company Atelier Brückner was presented with a challenge: to design the layout of a new permanent exhibition for CERN, one that would epitomize both the Organization and its research. The brief was concise but complex: the exhibit had to be symbolic of the Organization, use modern technology, engage and immerse visitors, and, preferably, use touch-screen technology. With the help of IArt, an interactive technology firm, and based on the content provided by CERN’s Education Group, Atelier Brückner developed the “Universe of Particles” exhibit as it is today. Its principal concept centred on the s...

  17. Greenhouse Earth: A Traveling Exhibition

    International Nuclear Information System (INIS)

    Booth, W.H.; Caesar, S.

    1992-09-01

    The Franklin Institute Science Museum provided an exhibit entitled the Greenhouse Earth: A Traveling Exhibition. This 3500 square-foot exhibit on global climate change was developed in collaboration with the Association of Science-Technology Centers. The exhibit opened at The Franklin Institute on February 14, 1992, welcoming 291,000 visitors over its three-month stay. During its three-year tour, Greenhouse Earth will travel to ten US cities, reaching two million visitors. Greenhouse Earth aims to deepen public understanding of the scientific issues of global warming and the conservation measures that can be taken to slow its effects. The exhibit features hands-on exhibitry, interactive computer programs and videos, a theater production, a ''demonstration cart,'' guided tours, and lectures. supplemental educational programs at the Institute included a teachers preview, a symposium on climate change, and a ''satellite field trip.'' The development of Greenhouse Earth included front-end and formative evaluation procedures. Evaluation includes interviews with visitors, prototypes, and summative surveys for participating museums. During its stay in Philadelphia, Greenhouse Earth was covered by the local and national press, with reviews in print and broadcast media. Greenhouse Earth is the first large-scale museum exhibit to address global climate change

  18. Homologation Reaction of Ketones with Diazo Compounds.

    Science.gov (United States)

    Candeias, Nuno R; Paterna, Roberta; Gois, Pedro M P

    2016-03-09

    This review covers the addition of diazo compounds to ketones to afford homologated ketones, either in the presence or in the absence of promoters or catalysts. Reactions with diazoalkanes, aryldiazomethanes, trimethylsilyldiazomethane, α-diazo esters, and disubstituted diazo compounds are covered, commenting on the complex regiochemistry of the reaction and the nature of the catalysts and promoters. The recent reports on the enantioselective version of ketone homologation reactions are gathered in one section, followed by reports on the use of cyclic ketones ring expansion in total synthesis. Although the first reports of this reaction appeared in the literature almost one century ago, the recent achievements, in particular, for the asymmetric version, forecast the development of new breakthroughs in the synthetically valuable field of diazo chemistry.

  19. Homological mirror symmetry and tropical geometry

    CERN Document Server

    Catanese, Fabrizio; Kontsevich, Maxim; Pantev, Tony; Soibelman, Yan; Zharkov, Ilia

    2014-01-01

    The relationship between Tropical Geometry and Mirror Symmetry goes back to the work of Kontsevich and Y. Soibelman (2000), who applied methods of non-archimedean geometry (in particular, tropical curves) to Homological Mirror Symmetry. In combination with the subsequent work of Mikhalkin on the “tropical” approach to Gromov-Witten theory, and the work of Gross and Siebert, Tropical Geometry has now become a powerful tool. Homological Mirror Symmetry is the area of mathematics concentrated around several categorical equivalences connecting symplectic and holomorphic (or algebraic) geometry. The central ideas first appeared in the work of Maxim Kontsevich (1993). Roughly speaking, the subject can be approached in two ways: either one uses Lagrangian torus fibrations of Calabi-Yau manifolds (the so-called Strominger-Yau-Zaslow picture, further developed by Kontsevich and Soibelman) or one uses Lefschetz fibrations of symplectic manifolds (suggested by Kontsevich and further developed by Seidel). Tropical Ge...

  20. Homological stability for unordered configuration spaces

    DEFF Research Database (Denmark)

    Randal-Williams, Oscar

    2013-01-01

    This paper consists of two related parts. In the first part we give a self-contained proof of homological stability for the spaces C_n(M;X) of configurations of n unordered points in a connected open manifold M with labels in a path-connected space X, with the best possible integral stability range...... of the spaces C_n(M) can be considered stable when M is a closed manifold. In this case there are no stabilisation maps, but one may still ask if the dimensions of the homology groups over some field stabilise with n. We prove that this is true when M is odd-dimensional, or when the field is F_2 or Q...

  1. Regulation of homologous recombination in eukaryotes

    OpenAIRE

    Heyer, Wolf-Dietrich; Ehmsen, Kirk T.; Liu, Jie

    2010-01-01

    Homologous recombination is required for accurate chromosome segregation during the first meiotic division and constitutes a key repair and tolerance pathway for complex DNA damage including DNA double-stranded breaks, interstrand crosslinks, and DNA gaps. In addition, recombination and replication are inextricably linked, as recombination recovers stalled and broken replication forks enabling the evolution of larger genomes/replicons. Defects in recombination lead to genomic instability and ...

  2. Khovanov homology of graph-links

    Energy Technology Data Exchange (ETDEWEB)

    Nikonov, Igor M [M. V. Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow (Russian Federation)

    2012-08-31

    Graph-links arise as the intersection graphs of turning chord diagrams of links. Speaking informally, graph-links provide a combinatorial description of links up to mutations. Many link invariants can be reformulated in the language of graph-links. Khovanov homology, a well-known and useful knot invariant, is defined for graph-links in this paper (in the case of the ground field of characteristic two). Bibliography: 14 titles.

  3. Quandle and Biquandle Homology Calculation in R

    Directory of Open Access Journals (Sweden)

    Roger Fenn

    2018-01-01

    Full Text Available In knot theory several knot invariants have been found over the last decades. This paper concerns itself with invariants of several of those invariants, namely the Homology of racks, quandles, biracks and biquandles. The software described in this paper calculates the rack, quandle and degenerate homology groups of racks and biracks. It works for any rack/quandle with finite elements where there are homology coefficients in 'Z'k. The up and down actions can be given either as a function of the elements of 'Z'k or provided as a matrix. When calculating a rack, the down action should coincide with the identity map. We have provided actions for both the general dihedral quandle and the group quandle over 'S'3. We also provide a second function to test if a set with a given action (or with both actions gives rise to a quandle or biquandle. The program is provided as an R package and can be found at https://github.com/ansgarwenzel/quhomology.   AMS subject classification: 57M27; 57M25

  4. Several aspects of some techniques avoiding homologous blood transfusions

    NARCIS (Netherlands)

    E.C.S.M. van Woerkens (Liesbeth)

    1998-01-01

    textabstractThe use of homologous blood products during anesthesia and surgery is not without risks. Complications due to homologous blood transfusions include transfusion reactions, isosensitization, transmission of infections (including HIV, hepatitis, CMV) and immunosuppression (resuiting in

  5. Computing Homology Group Generators of Images Using Irregular Graph Pyramids

    OpenAIRE

    Peltier , Samuel; Ion , Adrian; Haxhimusa , Yll; Kropatsch , Walter; Damiand , Guillaume

    2007-01-01

    International audience; We introduce a method for computing homology groups and their generators of a 2D image, using a hierarchical structure i.e. irregular graph pyramid. Starting from an image, a hierarchy of the image is built, by two operations that preserve homology of each region. Instead of computing homology generators in the base where the number of entities (cells) is large, we first reduce the number of cells by a graph pyramid. Then homology generators are computed efficiently on...

  6. Exhibition - Mathematics, A Beautiful Elsewhere

    CERN Multimedia

    2011-01-01

    From 21 October 2011 to 18 March 2012, the Fondation Cartier pour l’art contemporain will present the exhibition Mathematics: A Beautiful Elsewhere, an exhibition developed in association with the Institut des Hautes Études Scientifiques (IHÉS) and under the patronage of UNESCO. For this unprecedented event, the foundation invited mathematicians to work with artists with whom it has previously worked to create an exhibition that allows visitors to see, hear, do, interpret and think about mathematics. By bringing mathematics into its premises, the Fondation Cartier is itself undergoing the “sudden change of scenery” described by mathematician Alexandre Grothendieck. More information is available here. Fondation Cartier pour l’art contemporain 261, boulevard Raspail 75014 Paris http://fondation.cartier.com Private Visit For professors, researchers and all the staff of Mathematics departments...

  7. Glutathione reductase in leaves of cowpea: cloning of two cDNAs, expression and enzymatic activity under progressive drought stress, desiccation and abscisic acid treatment.

    Science.gov (United States)

    Contour-Ansel, Dominique; Torres-Franklin, Maria Lucia; Cruz DE Carvalho, Maria Helena; D'Arcy-Lameta, Agnès; Zuily-Fodil, Yasmine

    2006-12-01

    Reactive oxygen species are frequently produced when plants are exposed to abiotic stresses. Among the detoxication systems, two enzymes, ascorbate peroxidase and glutathione reductase (GR) play key roles. GR has also a central role in keeping the reduced glutathione pool during stress thus allowing the adjustments on the cellular redox reactions. The aim of this work was to study the variations in cytosolic and dual-targeted GR gene expression in the leaves of cowpea plants submitted to progressive drought, rapid desiccation and application of exogenous abscisic acid (ABA). Two cowpea (Vigna unguiculata) cultivars, one drought-resistant ('EPACE-1'), the other drought-sensitive ('1183') were submitted to progressive drought stress by withholding irrigation. Cut-off leaves were air-dried or treated with exogenous ABA. Two GR cDNAs, one cytosolic, the other dual-targeted to chloroplasts and mitochondria were isolated by PCR and cloned in plasmid vectors. Reverse-transcription PCR was used to study the variations in GR gene expression. Two new cDNAs encoding a putative dual-targeted and a cytosolic GR were cloned and sequenced from leaves of V. unguiculata. Drought stress induced an up-regulation of the expression of the cytosolic GR gene directly related to the intensity of the stress in both cultivars. The expression of dual-targeted GR was up-regulated by the drought treatment in the susceptible cultivar only. Under a fast desiccation, the '1183' cultivar responded later than the 'EPACE-1', although in 'EPACE-1' it was the cytosolic isoform which responded and in '1183' the dual-targeted one. Exogenous ABA enhanced significantly the activity and expression levels of GR in both cultivars after treatment for 24 h. These results demonstrate a noticeable activation in both cultivars of the antioxidant metabolism under a progressive water stress, which involves both GR genes in the case of the susceptible cultivar. Under a fast desiccation, the susceptible cultivar

  8. Large-scale analysis of full-length cDNAs from the tomato (Solanum lycopersicum) cultivar Micro-Tom, a reference system for the Solanaceae genomics.

    Science.gov (United States)

    Aoki, Koh; Yano, Kentaro; Suzuki, Ayako; Kawamura, Shingo; Sakurai, Nozomu; Suda, Kunihiro; Kurabayashi, Atsushi; Suzuki, Tatsuya; Tsugane, Taneaki; Watanabe, Manabu; Ooga, Kazuhide; Torii, Maiko; Narita, Takanori; Shin-I, Tadasu; Kohara, Yuji; Yamamoto, Naoki; Takahashi, Hideki; Watanabe, Yuichiro; Egusa, Mayumi; Kodama, Motoichiro; Ichinose, Yuki; Kikuchi, Mari; Fukushima, Sumire; Okabe, Akiko; Arie, Tsutomu; Sato, Yuko; Yazawa, Katsumi; Satoh, Shinobu; Omura, Toshikazu; Ezura, Hiroshi; Shibata, Daisuke

    2010-03-30

    The Solanaceae family includes several economically important vegetable crops. The tomato (Solanum lycopersicum) is regarded as a model plant of the Solanaceae family. Recently, a number of tomato resources have been developed in parallel with the ongoing tomato genome sequencing project. In particular, a miniature cultivar, Micro-Tom, is regarded as a model system in tomato genomics, and a number of genomics resources in the Micro-Tom-background, such as ESTs and mutagenized lines, have been established by an international alliance. To accelerate the progress in tomato genomics, we developed a collection of fully-sequenced 13,227 Micro-Tom full-length cDNAs. By checking redundant sequences, coding sequences, and chimeric sequences, a set of 11,502 non-redundant full-length cDNAs (nrFLcDNAs) was generated. Analysis of untranslated regions demonstrated that tomato has longer 5'- and 3'-untranslated regions than most other plants but rice. Classification of functions of proteins predicted from the coding sequences demonstrated that nrFLcDNAs covered a broad range of functions. A comparison of nrFLcDNAs with genes of sixteen plants facilitated the identification of tomato genes that are not found in other plants, most of which did not have known protein domains. Mapping of the nrFLcDNAs onto currently available tomato genome sequences facilitated prediction of exon-intron structure. Introns of tomato genes were longer than those of Arabidopsis and rice. According to a comparison of exon sequences between the nrFLcDNAs and the tomato genome sequences, the frequency of nucleotide mismatch in exons between Micro-Tom and the genome-sequencing cultivar (Heinz 1706) was estimated to be 0.061%. The collection of Micro-Tom nrFLcDNAs generated in this study will serve as a valuable genomic tool for plant biologists to bridge the gap between basic and applied studies. The nrFLcDNA sequences will help annotation of the tomato whole-genome sequence and aid in tomato functional

  9. Inconsistencies of genome annotations in apicomplexan parasites revealed by 5'-end-one-pass and full-length sequences of oligo-capped cDNAs

    Directory of Open Access Journals (Sweden)

    Sugano Sumio

    2009-07-01

    Full Text Available Abstract Background Apicomplexan parasites are causative agents of various diseases including malaria and have been targets of extensive genomic sequencing. We generated 5'-EST collections for six apicomplexa parasites using our full-length oligo-capping cDNA library method. To improve upon the current genome annotations, as well as to validate the importance for physical cDNA clone resources, we generated a large-scale collection of full-length cDNAs for several apicomplexa parasites. Results In this study, we used a total of 61,056 5'-end-single-pass cDNA sequences from Plasmodium falciparum, P. vivax, P. yoelii, P. berghei, Cryptosporidium parvum, and Toxoplasma gondii. We compared these partially sequenced cDNA sequences with the currently annotated gene models and observed significant inconsistencies between the two datasets. In particular, we found that on average 14% of the exons in the current gene models were not supported by any cDNA evidence, and that 16% of the current gene models may contain at least one mis-annotation and should be re-evaluated. We also identified a large number of transcripts that had been previously unidentified. For 732 cDNAs in T. gondii, the entire sequences were determined in order to evaluate the annotated gene models at the complete full-length transcript level. We found that 41% of the T. gondii gene models contained at least one inconsistency. We also identified and confirmed by RT-PCR 140 previously unidentified transcripts found in the intergenic regions of the current gene annotations. We show that the majority of these discrepancies are due to questionable predictions of one or two extra exons in the upstream or downstream regions of the genes. Conclusion Our data indicates that the current gene models are likely to still be incomplete and have much room for improvement. Our unique full-length cDNA information is especially useful for further refinement of the annotations for the genomes of

  10. Large-scale analysis of full-length cDNAs from the tomato (Solanum lycopersicum cultivar Micro-Tom, a reference system for the Solanaceae genomics

    Directory of Open Access Journals (Sweden)

    Kikuchi Mari

    2010-03-01

    Full Text Available Abstract Background The Solanaceae family includes several economically important vegetable crops. The tomato (Solanum lycopersicum is regarded as a model plant of the Solanaceae family. Recently, a number of tomato resources have been developed in parallel with the ongoing tomato genome sequencing project. In particular, a miniature cultivar, Micro-Tom, is regarded as a model system in tomato genomics, and a number of genomics resources in the Micro-Tom-background, such as ESTs and mutagenized lines, have been established by an international alliance. Results To accelerate the progress in tomato genomics, we developed a collection of fully-sequenced 13,227 Micro-Tom full-length cDNAs. By checking redundant sequences, coding sequences, and chimeric sequences, a set of 11,502 non-redundant full-length cDNAs (nrFLcDNAs was generated. Analysis of untranslated regions demonstrated that tomato has longer 5'- and 3'-untranslated regions than most other plants but rice. Classification of functions of proteins predicted from the coding sequences demonstrated that nrFLcDNAs covered a broad range of functions. A comparison of nrFLcDNAs with genes of sixteen plants facilitated the identification of tomato genes that are not found in other plants, most of which did not have known protein domains. Mapping of the nrFLcDNAs onto currently available tomato genome sequences facilitated prediction of exon-intron structure. Introns of tomato genes were longer than those of Arabidopsis and rice. According to a comparison of exon sequences between the nrFLcDNAs and the tomato genome sequences, the frequency of nucleotide mismatch in exons between Micro-Tom and the genome-sequencing cultivar (Heinz 1706 was estimated to be 0.061%. Conclusion The collection of Micro-Tom nrFLcDNAs generated in this study will serve as a valuable genomic tool for plant biologists to bridge the gap between basic and applied studies. The nrFLcDNA sequences will help annotation of the

  11. Learning from Exhibitions: Chuck Close.

    Science.gov (United States)

    Johnson, Mark M.

    1998-01-01

    Discusses the artwork of Chuck Close, who is well known for his over-sized portraits of fellow artists and anonymous sitters, and the exhibition of his work that premiered at New York's Museum of Modern Art before traveling to other cities in the United States. (CMK)

  12. A novel rat genomic simple repeat DNA with RNA-homology shows triplex (H-DNA)-like structure and tissue-specific RNA expression

    International Nuclear Information System (INIS)

    Dey, Indranil; Rath, Pramod C.

    2005-01-01

    Mammalian genome contains a wide variety of repetitive DNA sequences of relatively unknown function. We report a novel 227 bp simple repeat DNA (3.3 DNA) with a d {(GA) 7 A (AG) 7 } dinucleotide mirror repeat from the rat (Rattus norvegicus) genome. 3.3 DNA showed 75-85% homology with several eukaryotic mRNAs due to (GA/CU) n dinucleotide repeats by nBlast search and a dispersed distribution in the rat genome by Southern blot hybridization with [ 32 P]3.3 DNA. The d {(GA) 7 A (AG) 7 } mirror repeat formed a triplex (H-DNA)-like structure in vitro. Two large RNAs of 9.1 and 7.5 kb were detected by [ 32 P]3.3 DNA in rat brain by Northern blot hybridization indicating expression of such simple sequence repeats at RNA level in vivo. Further, several cDNAs were isolated from a rat cDNA library by [ 32 P]3.3 DNA probe. Three such cDNAs showed tissue-specific RNA expression in rat. pRT 4.1 cDNA showed strong expression of a 2.39 kb RNA in brain and spleen, pRT 5.5 cDNA showed strong expression of a 2.8 kb RNA in brain and a 3.9 kb RNA in lungs, and pRT 11.4 cDNA showed weak expression of a 2.4 kb RNA in lungs. Thus, genomic simple sequence repeats containing d (GA/CT) n dinucleotides are transcriptionally expressed and regulated in rat tissues. Such d (GA/CT) n dinucleotide repeats may form structural elements (e.g., triplex) which may be sites for functional regulation of genomic coding sequences as well as RNAs. This may be a general function of such transcriptionally active simple sequence repeats widely dispersed in mammalian genome

  13. A PHF8 homolog in C. elegans promotes DNA repair via homologous recombination.

    Directory of Open Access Journals (Sweden)

    Changrim Lee

    Full Text Available PHF8 is a JmjC domain-containing histone demethylase, defects in which are associated with X-linked mental retardation. In this study, we examined the roles of two PHF8 homologs, JMJD-1.1 and JMJD-1.2, in the model organism C. elegans in response to DNA damage. A deletion mutation in either of the genes led to hypersensitivity to interstrand DNA crosslinks (ICLs, while only mutation of jmjd-1.1 resulted in hypersensitivity to double-strand DNA breaks (DSBs. In response to ICLs, JMJD-1.1 did not affect the focus formation of FCD-2, a homolog of FANCD2, a key protein in the Fanconi anemia pathway. However, the dynamic behavior of RPA-1 and RAD-51 was affected by the mutation: the accumulations of both proteins at ICLs appeared normal, but their subsequent disappearance was retarded, suggesting that later steps of homologous recombination were defective. Similar changes in the dynamic behavior of RPA-1 and RAD-51 were seen in response to DSBs, supporting a role of JMJD-1.1 in homologous recombination. Such a role was also supported by our finding that the hypersensitivity of jmjd-1.1 worms to ICLs was rescued by knockdown of lig-4, a homolog of Ligase 4 active in nonhomologous end-joining. The hypersensitivity of jmjd-1.1 worms to ICLs was increased by rad-54 knockdown, suggesting that JMJD-1.1 acts in parallel with RAD-54 in modulating chromatin structure. Indeed, the level of histone H3 Lys9 tri-methylation, a marker of heterochromatin, was higher in jmjd-1.1 cells than in wild-type cells. We conclude that the histone demethylase JMJD-1.1 influences homologous recombination either by relaxing heterochromatin structure or by indirectly regulating the expression of multiple genes affecting DNA repair.

  14. Hochschild Homology and Cohomology of Klein Surfaces

    Directory of Open Access Journals (Sweden)

    Frédéric Butin

    2008-09-01

    Full Text Available Within the framework of deformation quantization, a first step towards the study of star-products is the calculation of Hochschild cohomology. The aim of this article is precisely to determine the Hochschild homology and cohomology in two cases of algebraic varieties. On the one hand, we consider singular curves of the plane; here we recover, in a different way, a result proved by Fronsdal and make it more precise. On the other hand, we are interested in Klein surfaces. The use of a complex suggested by Kontsevich and the help of Groebner bases allow us to solve the problem.

  15. Homology in vertebrates bone mineral structure

    International Nuclear Information System (INIS)

    Batdehmbehrehl, G.; Chultehm, D.; Sangaa, D.

    1999-01-01

    Using the neutron diffraction method a domination of low crystal syngonic (sp. gr. P63/m) phase Ca 5 [PO 4 ] 3 (OH, F, Cl) in bull and sheep bones as well as in the fossil dinosaur bone has been established and crystal phases in all the bones have identical structure (homology). The result becomes to be an important contribution to fundamental science such as biological evolution and to be useful in medical practice and solution of radiobiological problems connected with vertebrates and man. (author)

  16. Homological Perturbation Theory for Nonperturbative Integrals

    Science.gov (United States)

    Johnson-Freyd, Theo

    2015-11-01

    We use the homological perturbation lemma to produce explicit formulas computing the class in the twisted de Rham complex represented by an arbitrary polynomial. This is a non-asymptotic version of the method of Feynman diagrams. In particular, we explain that phenomena usually thought of as particular to asymptotic integrals in fact also occur exactly: integrals of the type appearing in quantum field theory can be reduced in a totally algebraic fashion to integrals over an Euler-Lagrange locus, provided this locus is understood in the scheme-theoretic sense, so that imaginary critical points and multiplicities of degenerate critical points contribute.

  17. Two RNAs or DNAs May Artificially Fuse Together at a Short Homologous Sequence (SHS) during Reverse Transcription or Polymerase Chain Reactions, and Thus Reporting an SHS-Containing Chimeric RNA Requires Extra Caution

    Science.gov (United States)

    Xie, Bingkun; Yang, Wei; Ouyang, Yongchang; Chen, Lichan; Jiang, Hesheng; Liao, Yuying; Liao, D. Joshua

    2016-01-01

    Tens of thousands of chimeric RNAs have been reported. Most of them contain a short homologous sequence (SHS) at the joining site of the two partner genes but are not associated with a fusion gene. We hypothesize that many of these chimeras may be technical artifacts derived from SHS-caused mis-priming in reverse transcription (RT) or polymerase chain reactions (PCR). We cloned six chimeric complementary DNAs (cDNAs) formed by human mitochondrial (mt) 16S rRNA sequences at an SHS, which were similar to several expression sequence tags (ESTs).These chimeras, which could not be detected with cDNA protection assay, were likely formed because some regions of the 16S rRNA are reversely complementary to another region to form an SHS, which allows the downstream sequence to loop back and anneal at the SHS to prime the synthesis of its complementary strand, yielding a palindromic sequence that can form a hairpin-like structure.We identified a 16S rRNA that ended at the 4th nucleotide(nt) of the mt-tRNA-leu was dominant and thus should be the wild type. We also cloned a mouse Bcl2-Nek9 chimeric cDNA that contained a 5-nt unmatchable sequence between the two partners, contained two copies of the reverse primer in the same direction but did not contain the forward primer, making it unclear how this Bcl2-Nek9 was formed and amplified. Moreover, a cDNA was amplified because one primer has 4 nts matched to the template, suggesting that there may be many more artificial cDNAs than we have realized, because the nuclear and mt genomes have many more 4-nt than 5-nt or longer homologues. Altogether, the chimeric cDNAs we cloned are good examples suggesting that many cDNAs may be artifacts due to SHS-caused mis-priming and thus greater caution should be taken when new sequence is obtained from a technique involving DNA polymerization. PMID:27148738

  18. Cloning of the anhidrotic ectodermal dysplasia gene: Identification of cDNAs associated with CpG islands mapped near translocation breakpoint in two female patients

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, A.K.; Schlessinger, D. [Washington Univ. School of Medicine, St. Louis, MO (United States); Kere, J. [Univ. of Helsinki (Finland)] [and others

    1994-09-01

    The gene for the X chromosomal developmental disorder anhidrotic ectodermal dysplasia (EDA) has been mapped to Xq12-q13 by linkage analysis and is expressed in a few females with chromosomal translocations involving band Xq12-q13. A yeast artificial chromosome (YAC) contig (2.0 Mb) spanning two translocation breakpoints has been assembled by sequence-tagged site (STS)-based chromosomal walking. The two translocation breakpoints (X:autosome translocations from the affected female patients) have been mapped less than 60 kb apart within a YAC contig. Unique probes and intragenic STSs (mapped between the two translocations) have been developed and a somatic cell hybrid carrying the translocated X chromosome from the AK patient has been analyzed by isolating unique probes that span the breakpoint. Several STSs made from intragenic sequences have been found to be conserved in mouse, hamster and monkey, but we have detected no mRNAs in a number of tissues tested. However, a probe and STS developed from the DNA spanning the AK breakpoint is conserved in mouse, hamster and monkey, and we have detected expressed sequences in skin cells and cDNA libraries. In addition, unique sequences have been obtained from two CpG islands in the region that maps proximal to the breakpoints. cDNAs containing these sequences are being studied as candidates for the gene affected in the etiology of EDA.

  19. Expression profiles of defence related cDNAs in oil palm (Elaeis guineensis Jacq.) inoculated with mycorrhizae and Trichoderma harzianum Rifai T32.

    Science.gov (United States)

    Tan, Yung-Chie; Wong, Mui-Yun; Ho, Chai-Ling

    2015-11-01

    Basal stem rot is one of the major diseases of oil palm (Elaies guineensis Jacq.) caused by pathogenic Ganoderma species. Trichoderma and mycorrhizae were proposed to be able to reduce the disease severity. However, their roles in improving oil palm defence system by possibly inducing defence-related genes in the host are not well characterized. To better understand that, transcript profiles of eleven putative defence-related cDNAs in the roots of oil palm inoculated with Trichoderma harzianum T32 and mycorrhizae at different time points were studied. Transcripts encoding putative Bowman-Birk protease inhibitor (EgBBI2) and defensin (EgDFS) increased more than 2 fold in mycorrhizae-treated roots at 6 weeks post inoculation (wpi) compared to those in controls. Transcripts encoding putative dehydrin (EgDHN), glycine-rich RNA binding protein (EgGRRBP), isoflavone reductase (EgIFR), type 2 ribosome inactivating protein (EgT2RIP), and EgDFS increased in the oil palm roots treated with T. harzianum at 6 and/or 12 wpi compared to those in the controls. Some of these genes were also expressed in oil palm roots treated with Ganoderma boninense. This study provides an insight of some defence-related genes induced by Trichoderma and mycorrhizae, and their roles as potential agents to boost the plant defence system. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  20. Molecular cloning of skin peptide precursor-encoding cDNAs from tibial gland secretion of the Giant Monkey Frog, Phyllomedusa bicolor (Hylidae, Anura).

    Science.gov (United States)

    König, Enrico; Clark, Valerie C; Shaw, Chris; Bininda-Emonds, Olaf R P

    2012-12-01

    The skins of phyllomedusine frogs have long been considered as being tremendously rich sources of bioactive peptides. Previous studies of both peptides and cloning of their precursor encoding cDNAs have relied upon methanolic skin extracts or the dissected skins of recently deceased specimens and have not considered the different glands in isolation. We therefore focused our attention on the tibial gland of the Giant Monkey Frog, Phyllomedusa bicolor and constructed a cDNA library from the skin secretion that was obtained via mechanical stimulation of this macrogland. Using shotgun cloning, four precursors encoding host-defense peptides were identified: two archetypal dermaseptins, a phyllokinin and a phylloseptin that is new for this species but has been recently described from the Waxy Monkey Leaf Frog, Phyllomedusa sauvagii. Our study is the first to report defensive peptides specifically isolated from anuran tibial glands, confirming the hypothesis that these glands also contribute to chemical defense. Moreover, the discovery of novel compounds for this otherwise very well characterized species suggests that this largely neglected gland might possess a different cocktail of secretions from glands elsewhere in the same animal. We will also discuss some evolutionary implications of our findings with respect to the adaptive plasticity of secretory glands. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Function of Rad51 paralogs in eukaryotic homologous recombinational repair

    International Nuclear Information System (INIS)

    Liu, N.; Skowronek, K.

    2003-01-01

    Full text: Homologous recombinational repair (HRR) is an important mechanism for maintaining genetic integrity and cancer prevention by accurately repair of DNA double strand breaks induced by environmental insults or occurred in DNA replication. A critical step in HRR is the polymerization of Rad51 on single stranded DNA to form nuclear protein filaments, the later conduct DNA strand paring and exchange between homologous strands. A number of proteins, including replication protein A (RPA), Rad52 and Rad51 paralogs, are suggested to modulate or facilitate the process of Rad51 filament formation. Five Rad51 paralogs, namely XRCC2, XRCC3, Rad51B, Rad51C and Rad51D have been identified in eucaryotic cells. These proteins show distant protein sequence identity to Rad51, to yeast Rad51 paralogs (Rad55 and Rad57) and to each other. Hamster or chicken mutants of Rad51 paralogs exhibit hypersensitivity to a variety of DNA damaging agents, especially cross-linking agents, and are defective in assembly of Rad51 onto HRR site after DNA damage. Recent data from our and other labs showed that Rad51 paralogs constitute two distinct complexes in cell extracts, one contains XRCC2, Rad51B, Rad51C and Rad51D, and the other contains Rad51C and XRCC3. Rad51C is involved in both complexes. Our results also showed that XRCC3-Rad51C complex interacts with Rad51 in vivo. Furthermore, overexpression of Rad52 can partially suppress the hypersensitivity of XRCC2 mutant irs1 to ionizing radiation and corrected the defects in Rad51 focus formation. These results suggest that XRCC2 and other Rad51 paralogs play a mediator function to Rad51 in the early stage of HRR

  2. Mobile Technologies in Museum Exhibitions

    OpenAIRE

    Sandra Medić; Nataša Pavlović

    2014-01-01

    In order to be up–to–date and give visitors a memorable and unique experience, museums are including usage of digital technologies in their exhibitions. Even though museums in Serbia are very important part of tourism offer, they still have traditional settings that are poorly interpreted. The majority of them have a scientific and historical review which is unattractive for various target groups of visitors and for museums it’s important to continually try out new ways in interpretation of t...

  3. A New Exhibition in Microcosm

    CERN Document Server

    2000-01-01

    Sebastien Pelletier explains states of matter to an enthusiastic group of youngsters during the opening of a new exhibition in Microcosm last week. The Fun with Physics workshop will be offered to all 13-14 year olds in school groups visiting CERN this year. The new Microcosm contents have been developed in collaboration with the local teaching community, and cover particles and the forces that act between them.

  4. "Big Science" exhibition at Balexert

    CERN Multimedia

    2008-01-01

    CERN is going out to meet those members of the general public who were unable to attend the recent Open Day. The Laboratory will be taking its "Big Science" exhibition from the Globe of Science and Innovation to the Balexert shopping centre from 19 to 31 May 2008. The exhibition, which shows the LHC and its experiments through the eyes of a photographer, features around thirty spectacular photographs measuring 4.5 metres high and 2.5 metres wide. Welcomed and guided around the exhibition by CERN volunteers, shoppers at Balexert will also have the opportunity to discover LHC components on display and watch films. "Fun with Physics" workshops will be held at certain times of the day. Main hall of the Balexert shopping centre, ground floor, from 9.00 a.m. to 7.00 p.m. Monday to Friday and from 10 a.m. to 6 p.m. on the two Saturdays. Call for volunteers All members of the CERN personnel are invited to enrol as volunteers to help welcom...

  5. Mobile Technologies in Museum Exhibitions

    Directory of Open Access Journals (Sweden)

    Sandra Medić

    2014-10-01

    Full Text Available In order to be up–to–date and give visitors a memorable and unique experience, museums are including usage of digital technologies in their exhibitions. Even though museums in Serbia are very important part of tourism offer, they still have traditional settings that are poorly interpreted. The majority of them have a scientific and historical review which is unattractive for various target groups of visitors and for museums it’s important to continually try out new ways in interpretation of their settings. Because technology continues to rapidly change the way we communicate, cultural institutions should adapt to new ways of communication with their visitors. This paper examines mobile technologies that can be used in museums to give visitors a different experience and transfer the knowledge innovatively. In that way it will be presented the modern concept of presentation of museum exhibitions, focusing on usage of mobile devices through mobile applications and QR codes. The paper provides the broad understanding of usage mobile technologies in museum exhibitions with its advantages and limitations. The research results can help the museums management to improve interpretation and communication with visitors and enrich the visitor experience.

  6. SANSparallel: interactive homology search against Uniprot.

    Science.gov (United States)

    Somervuo, Panu; Holm, Liisa

    2015-07-01

    Proteins evolve by mutations and natural selection. The network of sequence similarities is a rich source for mining homologous relationships that inform on protein structure and function. There are many servers available to browse the network of homology relationships but one has to wait up to a minute for results. The SANSparallel webserver provides protein sequence database searches with immediate response and professional alignment visualization by third-party software. The output is a list, pairwise alignment or stacked alignment of sequence-similar proteins from Uniprot, UniRef90/50, Swissprot or Protein Data Bank. The stacked alignments are viewed in Jalview or as sequence logos. The database search uses the suffix array neighborhood search (SANS) method, which has been re-implemented as a client-server, improved and parallelized. The method is extremely fast and as sensitive as BLAST above 50% sequence identity. Benchmarks show that the method is highly competitive compared to previously published fast database search programs: UBLAST, DIAMOND, LAST, LAMBDA, RAPSEARCH2 and BLAT. The web server can be accessed interactively or programmatically at http://ekhidna2.biocenter.helsinki.fi/cgi-bin/sans/sans.cgi. It can be used to make protein functional annotation pipelines more efficient, and it is useful in interactive exploration of the detailed evidence supporting the annotation of particular proteins of interest. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  7. Homologous Recombination—Experimental Systems, Analysis and Significance

    Science.gov (United States)

    Kuzminov, Andrei

    2014-01-01

    Homologous recombination is the most complex of all recombination events that shape genomes and produce material for evolution. Homologous recombination events are exchanges between DNA molecules in the lengthy regions of shared identity, catalyzed by a group of dedicated enzymes. There is a variety of experimental systems in E. coli and Salmonella to detect homologous recombination events of several different kinds. Genetic analysis of homologous recombination reveals three separate phases of this process: pre-synapsis (the early phase), synapsis (homologous strand exchange) and post-synapsis (the late phase). In E. coli, there are at least two independent pathway of the early phase and at least two independent pathways of the late phase. All this complexity is incongruent with the originally ascribed role of homologous recombination as accelerator of genome evolution: there is simply not enough duplication and repetition in enterobacterial genomes for homologous recombination to have a detectable evolutionary role, and therefore not enough selection to maintain such a complexity. At the same time, the mechanisms of homologous recombination are uniquely suited for repair of complex DNA lesions called chromosomal lesions. In fact, the two major classes of chromosomal lesions are recognized and processed by the two individual pathways at the early phase of homologous recombination. It follows, therefore, that homologous recombination events are occasional reflections of the continual recombinational repair, made possible in cases of natural or artificial genome redundancy. PMID:26442506

  8. Contemporary Developments in Cinema Exhibition

    OpenAIRE

    Hanson, Stuart

    2014-01-01

    he work offered for this PhD by Published Works charts the history of cinema exhibition in Britain from the late 1950s to the present. At the start of this period, cinemagoing as a form of public entertainment entered a long period of decline that was only arrested with the development and growth of multiplex cinemas in the 1980s and 1990s. Despite these changes, the feature film itself remained a culturally and commercially valuable artefact, though increasingly this meant the Hollywood fil...

  9. Construction of a novel kind of expression plasmid by homologous recombination in Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    CHEN; Xiangling

    2005-01-01

    [1]Brunelli, J. P., Pall, M. L., A series of yeast vectors for expression of cDNAs and other DNA sequences, Yeast, 1993, 9: 1299―1308.[2]Sikorski, R. S., Hieter, P., A system of shuttle vectors and yeast host strains designed for efficient manipulation of DNA in Saccharomyces cerevisiae, Genetics, 1989, 122: 19―27.[3]Bonneaud, N., Ozier-Kalogerogoulos, O., Li, G. et al., A family of low and high copy replicative, integrative and single-stranded S. cerevisiae /E. coli shuttle vector, Yeast, 1991, 7: 609―615.[4]Huo, K. K., Yu, L. L., Chen, X. J., Li, Y. Y., A stable vector for high-level expression and secretion of human interferon alpha A in yeast, Science in China, Ser. B, 1993, 36(5): 557―567.[5]Zhou, Z. X., Yuan, H. Y., He, W. et al., Expression of the modified HBsAg gene SA-28 directed by a constitutive promoter, Journal of Fudan university (Natural Science), 2000, 39(3): 264―268.[6]Paques, F., Haber, J. E., Multiple pathways of recombination induces by double-strand breaks in Saccharomyces cerevisiae, Microbiology and Molecular Biology Reviews, 1999, 63(2): 349―404.[7]Martin, K., Damage-induced recombination in the yeast Saccharomyces cerevisiae, Mutation Research, 2000, 451: 91―105.[8]Alira, S., Tomoko, O., Homologous recombination and the roles of double-strand breaks, TIBS, 1995, 20: 387―391.[9]Patrick, S., Kelly, M. T., Stephen, V. K., Recombination factor of Saccharomyces cerevisiae, Mutation Research, 2000, 451: 257―275.[10]Manivasakam, P., Weber, S. C., McElver, J., Schiestl, R. H., Micro-homology mediated PCR targeting in Saccharomyces cerevisiae, Nucleic Acids Res., 1995, 23(14): 2799―2800.[11]Baudin, A., Lacroute, F., Cullin, C., A simple and efficient method for direct gene deletion in Saccharomyces cerevisiae, Nucleic Acids Res., 1993, 21(14): 3329―3330.[12]Hua, S. B., Qiu, M., Chan, E., Zhu, L., Luo, Y., Minimum length of sequence homology required for in vivo cloning by homolo-gous recombination in yeast, Plasmid, 1997, 38

  10. Collaborative virtual environments art exhibition

    Science.gov (United States)

    Dolinsky, Margaret; Anstey, Josephine; Pape, Dave E.; Aguilera, Julieta C.; Kostis, Helen-Nicole; Tsoupikova, Daria

    2005-03-01

    This panel presentation will exhibit artwork developed in CAVEs and discuss how art methodologies enhance the science of VR through collaboration, interaction and aesthetics. Artists and scientists work alongside one another to expand scientific research and artistic expression and are motivated by exhibiting collaborative virtual environments. Looking towards the arts, such as painting and sculpture, computer graphics captures a visual tradition. Virtual reality expands this tradition to not only what we face, but to what surrounds us and even what responds to our body and its gestures. Art making that once was isolated to the static frame and an optimal point of view is now out and about, in fully immersive mode within CAVEs. Art knowledge is a guide to how the aesthetics of 2D and 3D worlds affect, transform, and influence the social, intellectual and physical condition of the human body through attention to psychology, spiritual thinking, education, and cognition. The psychological interacts with the physical in the virtual in such a way that each facilitates, enhances and extends the other, culminating in a "go together" world. Attention to sharing art experience across high-speed networks introduces a dimension of liveliness and aliveness when we "become virtual" in real time with others.

  11. Acetylcholine Receptor: Complex of Homologous Subunits

    Science.gov (United States)

    Raftery, Michael A.; Hunkapiller, Michael W.; Strader, Catherine D.; Hood, Leroy E.

    1980-06-01

    The acetylcholine receptor from the electric ray Torpedo californica is composed of five subunits; two are identical and the other three are structurally related to them. Microsequence analysis of the four polypeptides demonstrates amino acid homology among the subunits. Further sequence analysis of both membrane-bound and Triton-solubilized, chromatographically purified receptor gave the stoichiometry of the four subunits (40,000:50,000:60,000:65,000 daltons) as 2:1:1:1, indicating that this protein is a pentameric complex with a molecular weight of 255,000 daltons. Genealogical analysis suggests that divergence from a common ancestral gene occurred early in the evolution of the receptor. This shared ancestry argues that each of the four subunits plays a functional role in the receptor's physiological action.

  12. Regulation of Homologous Recombination by SUMOylation

    DEFF Research Database (Denmark)

    Pinela da Silva, Sonia Cristina

    factors such as the homologous recombination (HR) machinery. HR constitutes the main DSB repair pathway in Saccharomyces cerevisiae and despite being largely considered an error-free process and essential for genome stability, uncontrolled recombination can lead to loss of heterozygosity, translocations......, deletions, and genome rearrangements that can lead to cell death or cancer in humans. The post-translational modification by SUMO (small ubiquitinlike modifier) has proven to be an important regulator of HR and genome integrity, but the molecular mechanisms responsible for these roles are still unclear....... In this study I present new insights for the role of SUMOylation in regulating HR by dissecting the role of SUMO in the interaction between the central HR-mediator protein Rad52 and its paralogue Rad59 and the outcome of recombination. This data provides evidence for the importance of SUMO in promoting protein...

  13. Homological mirror symmetry. New developments and perspectives

    International Nuclear Information System (INIS)

    Kapustin, Anton; Kreuzer, Maximilian; Schlesinger, Karl-Georg

    2009-01-01

    Homological Mirror Symmetry, the study of dualities of certain quantum field theories in a mathematically rigorous form, has developed into a flourishing subject on its own over the past years. The present volume bridges a gap in the literature by providing a set of lectures and reviews that both introduce and representatively review the state-of-the art in the field from different perspectives. With contributions by K. Fukaya, M. Herbst, K. Hori, M. Huang, A. Kapustin, L. Katzarkov, A. Klemm, M. Kontsevich, D. Page, S. Quackenbush, E. Sharpe, P. Seidel, I. Smith and Y. Soibelman, this volume will be a reference on the topic for everyone starting to work or actively working on mathematical aspects of quantum field theory. (orig.)

  14. HOMOLOGOUS CYCLONES IN THE QUIET SUN

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xinting; Zhang, Jun; Li, Ting; Zhang, Yuzong; Yang, Shuhong, E-mail: yxt27272@mail.ustc.edu.cn, E-mail: zjun@nao.cas.cn, E-mail: liting@nao.cas.cn, E-mail: yuzong@nao.cas.cn, E-mail: shuhongyang@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2014-02-20

    Through observations with the Solar Dynamics Observatory Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager, we tracked one rotating network magnetic field (RNF) near the solar equator. It lasted for more than 100 hr, from 2013 February 23 to 28. During its evolution, three cyclones were found to be rooted in this structure. Each cyclone event lasted for about 8 to 10 hr. While near the polar region, another RNF was investigated. It lasted for a shorter time (∼70 hr), from 2013 July 7 to 9. There were two cyclones rooted in the RNF and each lasted for 8 and 11 hr, respectively. For the two given examples, the cyclones have a similar dynamic evolution, and thus we put forward a new term: homologous cyclones. The detected brightening in AIA 171 Å maps indicates the release of energy, which is potentially available to heat the corona.

  15. Modeling Non-homologous End Joining

    Science.gov (United States)

    Li, Yongfeng

    2013-01-01

    Non-homologous end joining (NHEJ) is the dominant DNA double strand break (DSB) repair pathway and involves several NHEJ proteins such as Ku, DNA-PKcs, XRCC4, Ligase IV and so on. Once DSBs are generated, Ku is first recruited to the DNA end, followed by other NHEJ proteins for DNA end processing and ligation. Because of the direct ligation of break ends without the need for a homologous template, NHEJ turns out to be an error-prone but efficient repair pathway. Some mechanisms have been proposed of how the efficiency of NHEJ repair is affected. The type of DNA damage is an important factor of NHEJ repair. For instance, the length of DNA fragment may determine the recruitment efficiency of NHEJ protein such as Ku [1], or the complexity of the DNA breaks [2] is accounted for the choice of NHEJ proteins and subpathway of NHEJ repair. On the other hand, the chromatin structure also plays a role of the accessibility of NHEJ protein to the DNA damage site. In this talk, some mathematical models of NHEJ, that consist of series of biochemical reactions complying with the laws of chemical reaction (e.g. mass action, etc.), will be introduced. By mathematical and numerical analysis and parameter estimation, the models are able to capture the qualitative biological features and show good agreement with experimental data. As conclusions, from the viewpoint of modeling, how the NHEJ proteins are recruited will be first discussed for connection between the classical sequential model [4] and recently proposed two-phase model [5]. Then how the NHEJ repair pathway is affected, by the length of DNA fragment [6], the complexity of DNA damage [7] and the chromatin structure [8], will be addressed

  16. More on homological supersymmetric quantum mechanics

    Science.gov (United States)

    Behtash, Alireza

    2018-03-01

    In this work, we first solve complex Morse flow equations for the simplest case of a bosonic harmonic oscillator to discuss localization in the context of Picard-Lefschetz theory. We briefly touch on the exact non-BPS solutions of the bosonized supersymmetric quantum mechanics on algebraic geometric grounds and report that their complex phases can be accessed through the cohomology of WKB 1-form of the underlying singular spectral curve subject to necessary cohomological corrections for nonzero genus. Motivated by Picard-Lefschetz theory, we write down a general formula for the index of N =4 quantum mechanics with background R -symmetry gauge fields. We conjecture that certain symmetries of the refined Witten index and singularities of the moduli space may be used to determine the correct intersection coefficients. A few examples, where this conjecture holds, are shown in both linear and closed quivers with rank-one quiver gauge groups. The R -anomaly removal along the "Morsified" relative homology cycles also called "Lefschetz thimbles" is shown to lead to the appearance of Stokes lines. We show that the Fayet-Iliopoulos parameters appear in the intersection coefficients for the relative homology of the quiver quantum mechanics resulting from dimensional reduction of 2 d N =(2 ,2 ) gauge theory on a circle and explicitly calculate integrals along the Lefschetz thimbles in N =4 C Pk -1 model. The Stokes jumping of coefficients and its relation to wall crossing phenomena is briefly discussed. We also find that the notion of "on-the-wall" index is related to the invariant Lefschetz thimbles under Stokes phenomena. An implication of the Lefschetz thimbles in constructing knots from quiver quantum mechanics is indicated.

  17. Cloning and expression analysis of cDNAs for ABA 8'-hydroxylase during sweet cherry fruit maturation and under stress conditions.

    Science.gov (United States)

    Ren, Jie; Sun, Liang; Wu, Jiefang; Zhao, Shengli; Wang, Canlei; Wang, Yanping; Ji, Kai; Leng, Ping

    2010-11-15

    Abscisic acid (ABA) plays a key role in various aspects of plant growth and development, including adaptation to environmental stress and fruit maturation in sweet cherry fruit. In higher plants, the level of ABA is determined by synthesis and catabolism. In order to gain insight into ABA synthesis and catabolism in sweet cherry fruit during maturation and under stress conditions, four cDNAs of PacCYP707A1 -PacCYP707A4 for 8'-hydroxylase, a key enzyme in the oxidative catabolism of ABA, and one cDNA of PacNCED1 for 9-cis-epoxycarotenoid dioxygenase, a key enzyme in the ABA biosynthetic pathway, were isolated from sweet cherry fruit (Prunus avium L.). The timing and pattern of PacNCED1 expression was coincident with that of ABA accumulation, which was correlated to maturation of sweet cherry fruit. All four PacCYP707As were expressed at varying intensities throughout fruit development and appeared to play overlapping roles in ABA catabolism throughout sweet cherry fruit development. The application of ABA enhanced the expression of PacCYP707A1 -PacCYP707A3 as well as PacNCED1, but downregulated the PacCYP707A4 transcript level. Expressions of PacCYP707A1, PacCYP707A3 and PacNCED1 were strongly increased by water stress. No significant differences in PacCYP707A2 and PacCYP707A4 expression were observed between dehydrated and control fruits. The results suggest that endogenous ABA content is modulated by a dynamic balance between biosynthesis and catabolism, which are regulated by PacNCED1 and PacCYP707As transcripts, respectively, during fruit maturation and under stress conditions. Copyright © 2010 Elsevier GmbH. All rights reserved.

  18. K-homology and K-cohomology constructions of relations

    International Nuclear Information System (INIS)

    Abd El-Sattar, A. Dabbour; Bayoumy, F.M.

    1990-08-01

    One of the important homology (cohomology) theories, based on systems of covering of the space, is the homology (cohomology) theory of relations. In the present work, by using the idea of K-homology and K-cohomology groups different varieties of the Dowker's theory are introduced and studied. These constructions are defined on the category of pairs of topological spaces and over a pair of coefficient groups. (author). 14 refs

  19. A local homology theory for linearly compact modules

    International Nuclear Information System (INIS)

    Nguyen Tu Cuong; Tran Tuan Nam

    2004-11-01

    We introduce a local homology theory for linearly modules which is in some sense dual to the local cohomology theory of A. Grothendieck. Some basic properties of local homology modules are shown such as: the vanishing and non-vanishing, the noetherianness of local homology modules. By using duality, we extend some well-known results in theory of local cohomology of A. Grothendieck. (author)

  20. On (co)homology of Frobenius Poisson algebras

    OpenAIRE

    Zhu, Can; Van Oystaeyen, Fred; ZHANG, Yinhuo

    2014-01-01

    In this paper, we study Poisson (co)homology of a Frobenius Poisson algebra. More precisely, we show that there exists a duality between Poisson homology and Poisson cohomology of Frobenius Poisson algebras, similar to that between Hochschild homology and Hochschild cohomology of Frobenius algebras. Then we use the non-degenerate bilinear form on a unimodular Frobenius Poisson algebra to construct a Batalin-Vilkovisky structure on the Poisson cohomology ring making it into a Batalin-Vilkovisk...

  1. A geometric model for Hochschild homology of Soergel bimodules

    DEFF Research Database (Denmark)

    Webster, Ben; Williamson, Geordie

    2008-01-01

    An important step in the calculation of the triply graded link homology of Khovanov and Rozansky is the determination of the Hochschild homology of Soergel bimodules for SL(n). We present a geometric model for this Hochschild homology for any simple group G, as B–equivariant intersection cohomology...... on generators whose degree is explicitly determined by the geometry of the orbit closure, and to describe its Hilbert series, proving a conjecture of Jacob Rasmussen....

  2. Heteromorphic Sex Chromosomes: Navigating Meiosis without a Homologous Partner

    OpenAIRE

    Checchi, Paula M.; Engebrecht, JoAnne

    2011-01-01

    Accurate chromosome segregation during meiosis relies on homology between the maternal and paternal chromosomes. Yet by definition, sex chromosomes of the heterogametic sex lack a homologous partner. Recent studies in a number of systems have shed light on the unique meiotic behavior of heteromorphic sex chromosomes, and highlight both the commonalities and differences in divergent species. During meiotic prophase, the homology-dependent processes of pairing, synapsis, and recombination have ...

  3. Enrico Fermi exhibition at CERN

    CERN Multimedia

    2002-01-01

    A touring exhibition celebrating the centenary of Enrico Fermi's birth in 1901 will be on display at CERN (Main Building, Mezzanine) from 12-27 September. You are cordially invited to the opening celebration on Thursday 12 September at 16:00 (Main Building, Council Chamber), which will include speechs from: Luciano Maiani Welcome and Introduction Arnaldo Stefanini Celebrating Fermi's Centenary in Documents and Pictures Antonino Zichichi The New 'Centro Enrico Fermi' at Via Panisperna Ugo Amaldi Fermi at Via Panisperna and the birth of Nuclear Medicine Jack Steinberger Fermi in Chicago Valentin Telegdi A Close-up of Fermi and the screening of a documentary video about Fermi: Scienziati a Pisa: Enrico Fermi (Scientists at Pisa: Enrico Fermi) created by Francesco Andreotti for La Limonaia from early film, photographs and sound recordings (In Italian, with English subtitles - c. 30 mins). This will be followed by an aperitif on the Mezz...

  4. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Colored Kauffman homology and super-A-polynomials

    International Nuclear Information System (INIS)

    Nawata, Satoshi; Ramadevi, P.; Zodinmawia

    2014-01-01

    We study the structural properties of colored Kauffman homologies of knots. Quadruple-gradings play an essential role in revealing the differential structure of colored Kauffman homology. Using the differential structure, the Kauffman homologies carrying the symmetric tensor products of the vector representation for the trefoil and the figure-eight are determined. In addition, making use of relations from representation theory, we also obtain the HOMFLY homologies colored by rectangular Young tableaux with two rows for these knots. Furthermore, the notion of super-A-polynomials is extended in order to encompass two-parameter deformations of PSL(2,ℂ) character varieties

  6. Sequence homology at the breakpoint and clinical phenotype of mitochondrial DNA deletion syndromes.

    Science.gov (United States)

    Sadikovic, Bekim; Wang, Jing; El-Hattab, Ayman W; Landsverk, Megan; Douglas, Ganka; Brundage, Ellen K; Craigen, William J; Schmitt, Eric S; Wong, Lee-Jun C

    2010-12-20

    Mitochondrial DNA (mtDNA) deletions are a common cause of mitochondrial disorders. Large mtDNA deletions can lead to a broad spectrum of clinical features with different age of onset, ranging from mild mitochondrial myopathies (MM), progressive external ophthalmoplegia (PEO), and Kearns-Sayre syndrome (KSS), to severe Pearson syndrome. The aim of this study is to investigate the molecular signatures surrounding the deletion breakpoints and their association with the clinical phenotype and age at onset. MtDNA deletions in 67 patients were characterized using array comparative genomic hybridization (aCGH) followed by PCR-sequencing of the deletion junctions. Sequence homology including both perfect and imperfect short repeats flanking the deletion regions were analyzed and correlated with clinical features and patients' age group. In all age groups, there was a significant increase in sequence homology flanking the deletion compared to mtDNA background. The youngest patient group (deletion distribution in size and locations, with a significantly lower sequence homology flanking the deletion, and the highest percentage of deletion mutant heteroplasmy. The older age groups showed rather discrete pattern of deletions with 44% of all patients over 6 years old carrying the most common 5 kb mtDNA deletion, which was found mostly in muscle specimens (22/41). Only 15% (3/20) of the young patients (deletion, which is usually present in blood rather than muscle. This group of patients predominantly (16 out of 17) exhibit multisystem disorder and/or Pearson syndrome, while older patients had predominantly neuromuscular manifestations including KSS, PEO, and MM. In conclusion, sequence homology at the deletion flanking regions is a consistent feature of mtDNA deletions. Decreased levels of sequence homology and increased levels of deletion mutant heteroplasmy appear to correlate with earlier onset and more severe disease with multisystem involvement.

  7. EU Climate Change Exhibition Held

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>On April 25, the CPAFFC, the China-EU Association (CEUA) and the Delegation of the European Commission to China jointly held the opening ceremony for the EU Exhibition on Climate Change in the CPAFFC. He Luli, former vice chairperson of the NPC Standing Committee and honorary president of the CEUA, Jose Manuel Barroso, president of the European Commission, and Li Jianping, vice president of the CPAFFC, attended the opening ceremony and made speeches. Honorary President He Luli highly praised the achievements made by China and the EU in their longtime cooperation of mutual benefits in various fields including environmental protection. She said, for many years China and EU have both committed to the development of all-round strategic partnership and establishment of a multi-level mechanism of political dialogue. She expressed, with increasing enthusiasm the CEUA would continue to actively carry out nongovernmental exchanges between China and the EU, and promote cooperation between the two sides in the fields of economy, society, environmental protection, science and technology, culture, etc.

  8. Characterization of four plasma membrane aquaporins in tulip petals: a putative homolog is regulated by phosphorylation.

    Science.gov (United States)

    Azad, Abul Kalam; Katsuhara, Maki; Sawa, Yoshihiro; Ishikawa, Takahiro; Shibata, Hitoshi

    2008-08-01

    We suggested previously that temperature-dependent tulip (Tulipa gesneriana) petal movement that is concomitant with water transport is regulated by reversible phosphorylation of an unidentified plasma membrane intrinsic protein (PIP). In this study, four full-length cDNAs of PIPs from tulip petals were identified and cloned. Two PIPs, namely TgPIP1;1 and TgPIP1;2, are members of the PIP1 subfamily, and the remaining two PIPs, namely TgPIP2;1 and TgPIP2;2, belong to the PIP2 subfamily of aquaporins and were named according to the nomenclature of PIP genes in plants. Of these four homologs, only TgPIP2;2 displayed significant water channel activity in the heterologous expression assay using Xenopus laevis oocytes. The water channel activity of this functional isoform was abolished by mercury and was affected by inhibitors of protein kinase and protein phosphatase. Using a site-directed mutagenesis approach to substitute several serine residues with alanine, and assessing water channel activity using the methylotrophic yeast Pichia pastoris expression assay, we showed that Ser35, Ser116 and Ser274 are the putative phosphorylation sites of TgPIP2;2. Real-time reverse transcription-PCR analysis revealed that the transcript levels of TgPIP1;1 and TgPIP1;2 in tulip petals, stems, leaves, bulbs and roots are very low when compared with those of TgPIP2;1 and TgPIP2;2. The transcript level of TgPIP2;1 is negligible in roots, and TgPIP2;2 is ubiquitously expressed in all organs with significant transcript levels. From the data reported herein, we suggest that TgPIP2;2 might be modulated by phosphorylation and dephosphorylation for regulating water channel activity, and may play a role in transcellular water transport in all tulip organs.

  9. CBH1 homologs and varian CBH1 cellulase

    Energy Technology Data Exchange (ETDEWEB)

    Goedegebuur, Frits; Gualfetti, Peter; Mitchinson, Colin; Neefe, Paulien

    2014-07-01

    Disclosed are a number of homologs and variants of Hypocrea jecorina Cel7A (formerly Trichoderma reesei cellobiohydrolase I or CBH1), nucleic acids encoding the same and methods for producing the same. The homologs and variant cellulases have the amino acid sequence of a glycosyl hydrolase of family 7A wherein one or more amino acid residues are substituted and/or deleted.

  10. The Causes of Quasi-homologous CMEs

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lijuan; Wang, Yuming; Liu, Rui; Zhou, Zhenjun; Liu, Jiajia; Liu, Kai; Shen, Chenglong; Zhang, Quanhao [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei, Anhui, 230026 (China); Temmer, M.; Thalmann, J. K.; Veronig, A. M., E-mail: ymwang@ustc.edu.cn, E-mail: ljliu@mail.ustc.edu.cn [Institute of Physics/IGAM, University of Graz, Universitätsplatz 5/II, A-8010 Graz (Austria)

    2017-08-01

    In this paper, we identified the magnetic source locations of 142 quasi-homologous (QH) coronal mass ejections (CMEs), of which 121 are from solar cycle (SC) 23 and 21 from SC 24. Among those CMEs, 63% originated from the same source location as their predecessor (defined as S-type), while 37% originated from a different location within the same active region as their predecessor (defined as D-type). Their distinctly different waiting time distributions, peaking around 7.5 and 1.5 hr for S- and D-type CMEs, suggest that they might involve different physical mechanisms with different characteristic timescales. Through detailed analysis based on nonlinear force-free coronal magnetic field modeling of two exemplary cases, we propose that the S-type QH CMES might involve a recurring energy release process from the same source location (by magnetic free energy replenishment), whereas the D-type QH CMEs can happen when a flux tube system is disturbed by a nearby CME.

  11. Torus actions, combinatorial topology, and homological algebra

    International Nuclear Information System (INIS)

    Bukhshtaber, V M; Panov, T E

    2000-01-01

    This paper is a survey of new results and open problems connected with fundamental combinatorial concepts, including polytopes, simplicial complexes, cubical complexes, and arrangements of subspaces. Attention is concentrated on simplicial and cubical subdivisions of manifolds, and especially on spheres. Important constructions are described that enable one to study these combinatorial objects by using commutative and homological algebra. The proposed approach to combinatorial problems is based on the theory of moment-angle complexes recently developed by the authors. The crucial construction assigns to each simplicial complex K with m vertices a T m -space Z K with special bigraded cellular decomposition. In the framework of this theory, well-known non-singular toric varieties arise as orbit spaces of maximally free actions of subtori on moment-angle complexes corresponding to simplicial spheres. It is shown that diverse invariants of simplicial complexes and related combinatorial-geometric objects can be expressed in terms of bigraded cohomology rings of the corresponding moment-angle complexes. Finally, it is shown that the new relationships between combinatorics, geometry, and topology lead to solutions of some well-known topological problems

  12. Statistical Inference for Porous Materials using Persistent Homology.

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Chul [Univ. of Georgia, Athens, GA (United States); Heath, Jason E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mitchell, Scott A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-12-01

    We propose a porous materials analysis pipeline using persistent homology. We rst compute persistent homology of binarized 3D images of sampled material subvolumes. For each image we compute sets of homology intervals, which are represented as summary graphics called persistence diagrams. We convert persistence diagrams into image vectors in order to analyze the similarity of the homology of the material images using the mature tools for image analysis. Each image is treated as a vector and we compute its principal components to extract features. We t a statistical model using the loadings of principal components to estimate material porosity, permeability, anisotropy, and tortuosity. We also propose an adaptive version of the structural similarity index (SSIM), a similarity metric for images, as a measure to determine the statistical representative elementary volumes (sREV) for persistence homology. Thus we provide a capability for making a statistical inference of the uid ow and transport properties of porous materials based on their geometry and connectivity.

  13. Low-Threshold Lasing from 2D Homologous Organic-Inorganic Hybrid Ruddlesden-Popper Perovskite Single Crystals.

    Science.gov (United States)

    Raghavan, Chinnambedu Murugesan; Chen, Tzu-Pei; Li, Shao-Sian; Chen, Wei-Liang; Lo, Chao-Yuan; Liao, Yu-Ming; Haider, Golam; Lin, Cheng-Chieh; Chen, Chia-Chun; Sankar, Raman; Chang, Yu-Ming; Chou, Fang-Cheng; Chen, Chun-Wei

    2018-05-09

    Organic-inorganic hybrid two-dimensional (2D) perovskites have recently attracted great attention in optical and optoelectronic applications due to their inherent natural quantum-well structure. We report the growth of high-quality millimeter-sized single crystals belonging to homologous two-dimensional (2D) hybrid organic-inorganic Ruddelsden-Popper perovskites (RPPs) of (BA) 2 (MA) n-1 Pb n I 3 n+1 ( n = 1, 2, and 3) by a slow evaporation at a constant-temperature (SECT) solution-growth strategy. The as-grown 2D hybrid perovskite single crystals exhibit excellent crystallinity, phase purity, and spectral uniformity. Low-threshold lasing behaviors with different emission wavelengths at room temperature have been observed from the homologous 2D hybrid RPP single crystals. Our result demonstrates that solution-growth homologous organic-inorganic hybrid 2D perovskite single crystals open up a new window as a promising candidate for optical gain media.

  14. Cloning of cDNAs coding for the heavy chain region and connecting region of human factor V, a blood coagulation factor with four types of internal repeats

    International Nuclear Information System (INIS)

    Kane, W.H.; Ichinose, A.; Hagen, F.S.; Davie, E.W.

    1987-01-01

    Human factor V is a high molecular weight plasma glycoprotein that participates as a cofactor in the conversion of prothrombin to thrombin by factor X/sub a/. Prior to its participation in the coagulation cascade, factor V is converted to factor V/sub a/ by thrombin generating a heavy chain and a light chain, and these two chains are held together by calcium ions. A connecting region originally located between the heavy and light chains is liberated during the activation reaction. In a previous study, a cDNA of 2970 nucleotides that codes for the carboxyl-terminal 938 amino acids of factor V was isolated and characterized from a Hep G2 cDNA library. This cDNA has been used to obtain additional clones from Hep G2 and human liver cDNA libraries. Furthermore, a Hep G2 cDNA library prepared with an oligonucleotide from the 5' end of these cDNAs was screened to obtain overlapping cDNA clones that code for the amino-terminal region of the molecule. The composite sequence of these clones spans 6911 nucleotides and is consistent with the size of the factor V message present in Hep G2 cells (approximately 7 kilobases). The cDNA codes for a leader sequence of 28 amino acids and a mature protein of 2196 amino acids. The amino acid sequence predicted from the cDNA was in complete agreement with 139 amino acid residues that were identified by Edman degradation of cyanogen bromide peptides isolated from the heavy chain region and connecting region of plasma factor V. The domain structure of human factor V is similar to that previously reported for human coagulation factor VIII. Two types of tandem repeats (17 and 9 amino acids) have also been identified in the connecting region of factor V. The present data indicate that the amino acid sequence in the heavy and light chain regions of factor V is ∼ 40% identical with the corresponding regions of factor VIII

  15. Homologous series of induced early mutants in indican rice. Pt.1. The production of homologous series of early mutants

    International Nuclear Information System (INIS)

    Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

    1999-01-01

    The percentage of homologous series of early mutants induced from the same Indican rice variety were almost the same (1.37%∼1.64%) in 1983∼1993, but the ones from the different eco-typical varieties were different. The early variety was 0.73%, the mid variety was 1.51%, and the late variety was 1.97%. The percentage of homologous series of early mutants from the varieties with the same pedigree and relationship were similar, but the one from the cog nation were lower than those from distant varieties. There are basic laws and characters in the homologous series of early mutants: 1. The inhibited phenotype is the basic of the homologous series of early mutants; 2. The production of the homologous series of early mutants is closely related with the growing period of the parent; 3. The parallel mutation of the stem and leaves are simultaneously happened with the variation of early or late maturing; 4. The occurrence of the homologous series of early mutants is in a state of imbalance. According to the law of parallel variability, the production of homologous series of early mutants can be predicted as long as the parents' classification of plant, pedigree and ecological type are identified. Therefore, the early breeding can be guided by the law of homologous series of early mutants

  16. Productive Homologous and Non-homologous Recombination of Hepatitis C Virus in Cell Culture

    Science.gov (United States)

    Li, Yi-Ping; Mikkelsen, Lotte S.; Gottwein, Judith M.; Bukh, Jens

    2013-01-01

    Genetic recombination is an important mechanism for increasing diversity of RNA viruses, and constitutes a viral escape mechanism to host immune responses and to treatment with antiviral compounds. Although rare, epidemiologically important hepatitis C virus (HCV) recombinants have been reported. In addition, recombination is an important regulatory mechanism of cytopathogenicity for the related pestiviruses. Here we describe recombination of HCV RNA in cell culture leading to production of infectious virus. Initially, hepatoma cells were co-transfected with a replicating JFH1ΔE1E2 genome (genotype 2a) lacking functional envelope genes and strain J6 (2a), which has functional envelope genes but does not replicate in culture. After an initial decrease in the number of HCV positive cells, infection spread after 13–36 days. Sequencing of recovered viruses revealed non-homologous recombinants with J6 sequence from the 5′ end to the NS2–NS3 region followed by JFH1 sequence from Core to the 3′ end. These recombinants carried duplicated sequence of up to 2400 nucleotides. HCV replication was not required for recombination, as recombinants were observed in most experiments even when two replication incompetent genomes were co-transfected. Reverse genetic studies verified the viability of representative recombinants. After serial passage, subsequent recombination events reducing or eliminating the duplicated region were observed for some but not all recombinants. Furthermore, we found that inter-genotypic recombination could occur, but at a lower frequency than intra-genotypic recombination. Productive recombination of attenuated HCV genomes depended on expression of all HCV proteins and tolerated duplicated sequence. In general, no strong site specificity was observed. Non-homologous recombination was observed in most cases, while few homologous events were identified. A better understanding of HCV recombination could help identification of natural recombinants

  17. Productive homologous and non-homologous recombination of hepatitis C virus in cell culture

    DEFF Research Database (Denmark)

    Scheel, Troels K H; Galli, Andrea; Li, Yi-Ping

    2013-01-01

    . In addition, recombination is an important regulatory mechanism of cytopathogenicity for the related pestiviruses. Here we describe recombination of HCV RNA in cell culture leading to production of infectious virus. Initially, hepatoma cells were co-transfected with a replicating JFH1ΔE1E2 genome (genotype 2a......) lacking functional envelope genes and strain J6 (2a), which has functional envelope genes but does not replicate in culture. After an initial decrease in the number of HCV positive cells, infection spread after 13-36 days. Sequencing of recovered viruses revealed non-homologous recombinants with J6...

  18. Detecting false positive sequence homology: a machine learning approach.

    Science.gov (United States)

    Fujimoto, M Stanley; Suvorov, Anton; Jensen, Nicholas O; Clement, Mark J; Bybee, Seth M

    2016-02-24

    Accurate detection of homologous relationships of biological sequences (DNA or amino acid) amongst organisms is an important and often difficult task that is essential to various evolutionary studies, ranging from building phylogenies to predicting functional gene annotations. There are many existing heuristic tools, most commonly based on bidirectional BLAST searches that are used to identify homologous genes and combine them into two fundamentally distinct classes: orthologs and paralogs. Due to only using heuristic filtering based on significance score cutoffs and having no cluster post-processing tools available, these methods can often produce multiple clusters constituting unrelated (non-homologous) sequences. Therefore sequencing data extracted from incomplete genome/transcriptome assemblies originated from low coverage sequencing or produced by de novo processes without a reference genome are susceptible to high false positive rates of homology detection. In this paper we develop biologically informative features that can be extracted from multiple sequence alignments of putative homologous genes (orthologs and paralogs) and further utilized in context of guided experimentation to verify false positive outcomes. We demonstrate that our machine learning method trained on both known homology clusters obtained from OrthoDB and randomly generated sequence alignments (non-homologs), successfully determines apparent false positives inferred by heuristic algorithms especially among proteomes recovered from low-coverage RNA-seq data. Almost ~42 % and ~25 % of predicted putative homologies by InParanoid and HaMStR respectively were classified as false positives on experimental data set. Our process increases the quality of output from other clustering algorithms by providing a novel post-processing method that is both fast and efficient at removing low quality clusters of putative homologous genes recovered by heuristic-based approaches.

  19. AaeAP1 and AaeAP2: novel antimicrobial peptides from the venom of the scorpion, Androctonus aeneas: structural characterisation, molecular cloning of biosynthetic precursor-encoding cDNAs and engineering of analogues with enhanced antimicrobial and anticancer activities.

    Science.gov (United States)

    Du, Qiang; Hou, Xiaojuan; Wang, Lei; Zhang, Yingqi; Xi, Xinping; Wang, Hui; Zhou, Mei; Duan, Jinao; Wei, Minjie; Chen, Tianbao; Shaw, Chris

    2015-01-23

    The main functions of the abundant polypeptide toxins present in scorpion venoms are the debilitation of arthropod prey or defence against predators. These effects are achieved mainly through the blocking of an array of ion channel types within the membranes of excitable cells. However, while these ion channel-blocking toxins are tightly-folded by multiple disulphide bridges between cysteine residues, there are additional groups of peptides in the venoms that are devoid of cysteine residues. These non-disulphide bridged peptides are the subject of much research interest, and among these are peptides that exhibit antimicrobial activity. Here, we describe two novel non-disulphide-bridged antimicrobial peptides that are present in the venom of the North African scorpion, Androctonus aeneas. The cDNAs encoding the biosynthetic precursors of both peptides were cloned from a venom-derived cDNA library using 3'- and 5'-RACE strategies. Both translated precursors contained open-reading frames of 74 amino acid residues, each encoding one copy of a putative novel nonadecapeptide, whose primary structures were FLFSLIPSVIAGLVSAIRN and FLFSLIPSAIAGLVSAIRN, respectively. Both peptides were C-terminally amidated. Synthetic versions of each natural peptide displayed broad-spectrum antimicrobial activities, but were devoid of antiproliferative activity against human cancer cell lines. However, synthetic analogues of each peptide, engineered for enhanced cationicity and amphipathicity, exhibited increases in antimicrobial potency and acquired antiproliferative activity against a range of human cancer cell lines. These data clearly illustrate the potential that natural peptide templates provide towards the design of synthetic analogues for therapeutic exploitation.

  20. AaeAP1 and AaeAP2: Novel Antimicrobial Peptides from the Venom of the Scorpion, Androctonus aeneas: Structural Characterisation, Molecular Cloning of Biosynthetic Precursor-Encoding cDNAs and Engineering of Analogues with Enhanced Antimicrobial and Anticancer Activities

    Directory of Open Access Journals (Sweden)

    Qiang Du

    2015-01-01

    Full Text Available The main functions of the abundant polypeptide toxins present in scorpion venoms are the debilitation of arthropod prey or defence against predators. These effects are achieved mainly through the blocking of an array of ion channel types within the membranes of excitable cells. However, while these ion channel-blocking toxins are tightly-folded by multiple disulphide bridges between cysteine residues, there are additional groups of peptides in the venoms that are devoid of cysteine residues. These non-disulphide bridged peptides are the subject of much research interest, and among these are peptides that exhibit antimicrobial activity. Here, we describe two novel non-disulphide-bridged antimicrobial peptides that are present in the venom of the North African scorpion, Androctonus aeneas. The cDNAs encoding the biosynthetic precursors of both peptides were cloned from a venom-derived cDNA library using 3'- and 5'-RACE strategies. Both translated precursors contained open-reading frames of 74 amino acid residues, each encoding one copy of a putative novel nonadecapeptide, whose primary structures were FLFSLIPSVIAGLVSAIRN and FLFSLIPSAIAGLVSAIRN, respectively. Both peptides were C-terminally amidated. Synthetic versions of each natural peptide displayed broad-spectrum antimicrobial activities, but were devoid of antiproliferative activity against human cancer cell lines. However, synthetic analogues of each peptide, engineered for enhanced cationicity and amphipathicity, exhibited increases in antimicrobial potency and acquired antiproliferative activity against a range of human cancer cell lines. These data clearly illustrate the potential that natural peptide templates provide towards the design of synthetic analogues for therapeutic exploitation.

  1. Intron loss from the NADH dehydrogenase subunit 4 gene of lettuce mitochondrial DNA: evidence for homologous recombination of a cDNA intermediate.

    Science.gov (United States)

    Geiss, K T; Abbas, G M; Makaroff, C A

    1994-04-01

    The mitochondrial gene coding for subunit 4 of the NADH dehydrogenase complex I (nad4) has been isolated and characterized from lettuce, Lactuca sativa. Analysis of nad4 genes in a number of plants by Southern hybridization had previously suggested that the intron content varied between species. Characterization of the lettuce gene confirms this observation. Lettuce nad4 contains two exons and one group IIA intron, whereas previously sequenced nad4 genes from turnip and wheat contain three group IIA introns. Northern analysis identified a transcript of 1600 nucleotides, which represents the mature nad4 mRNA and a primary transcript of 3200 nucleotides. Sequence analysis of lettuce and turnip nad4 cDNAs was used to confirm the intron/exon border sequences and to examine RNA editing patterns. Editing is observed at the 5' and 3' ends of the lettuce transcript, but is absent from sequences that correspond to exons two, three and the 5' end of exon four in turnip and wheat. In contrast, turnip transcripts are highly edited in this region, suggesting that homologous recombination of an edited and spliced cDNA intermediate was involved in the loss of introns two and three from an ancestral lettuce nad4 gene.

  2. The K-homology of nets of C∗-algebras

    Science.gov (United States)

    Ruzzi, Giuseppe; Vasselli, Ezio

    2014-12-01

    Let X be a space, intended as a possibly curved space-time, and A a precosheaf of C∗-algebras on X. Motivated by algebraic quantum field theory, we study the Kasparov and Θ-summable K-homology of A interpreting them in terms of the holonomy equivariant K-homology of the associated C∗-dynamical system. This yields a characteristic class for K-homology cycles of A with values in the odd cohomology of X, that we interpret as a generalized statistical dimension.

  3. Seed coat development in Velloziaceae: primary homology assessment and insights on seed coat evolution.

    Science.gov (United States)

    Sousa-Baena, Mariane S; de Menezes, Nanuza L

    2014-09-01

    • Seed coat characteristics have historically been used to infer taxonomic relationships and are a potential source of characters for phylogenetic reconstruction. In particular, seed coat morphoanatomy has never been studied in detail in Velloziaceae. One character based on seed surface microsculpture has been used in phylogenies, but was excluded from recent studies owing to problems in primary homology. This work aimed to clarify the origin and general composition of seed coat cell layers in Velloziaceae and to propose hypotheses of primary homology among seed characters.• Seed coat development of 24 Velloziaceae species, comprising nine genera, and one species of Pandanaceae (outgroup) was studied using standard anatomical methods. Developmental data were interpreted in the light of a recently published phylogeny.• Eight types of seed coat were identified. Whereas the most common type has four distinct cell layers (two-layered tegmen and testa), we encountered much more variation in seed coat composition than previously reported, the analysis of which revealed some potential synapomorphies. For instance, an exotesta with spiral thickenings may be a synapomorphy of Barbacenia.• Our results showed that the character states previously used in phylogenies are not based on homologous layers and that the same state was misattributed to species exhibiting quite different seed coats. This study is a first step toward a better understanding of seed coat structure evolution in Velloziaceae. © 2014 Botanical Society of America, Inc.

  4. Crotacetin, a novel snake venom C-type lectin, is homolog of convulxin

    Directory of Open Access Journals (Sweden)

    G. Rádis-Baptista

    2005-12-01

    Full Text Available Snake venom (sv C-type lectins encompass a group of hemorrhagic toxins, which are able to interfere with hemostasis. They share significant similarity in their primary structures with C-type lectins of other animals, and also present a conserved carbohydrate recognition domain (CRD. A very well studied sv C-type lectin is the heterodimeric toxin, convulxin (CVX, from the venoms of South American rattlesnakes, Crotalus durissus terrificus and C. d. cascavella. It consists of two subunits, alfa (CVXalpha , 13.9 kDa and beta (CVXbeta , 12.6 kDa, joined by inter and intra-chain disulfide bounds, and is arranged in a tetrameric alpha4beta4 conformation. Convulxin is able to activate platelet and induce their aggregation by acting via p62/GPVI collagen receptor. Several cDNA precursors, homolog of CVX subunits, were cloned by PCR homology screening. As determined by computational analysis, one of them, named crotacetin beta subunit, was predicted as a polypeptide with a tridimensional conformation very similar to other subunits of convulxin-like snake toxins. Crotacetin was purified from C. durissus venoms by gel permeation and reverse phase high performance liquid chromatography. The heterodimeric crotacetin is expressed in the venoms of several C. durissus subspecies, but it is prevalent in the venom of C. durissus cascavella. As inferred from homology modeling, crotacetin induces platelet aggregation but noticeably exhibits antimicrobial activity against Gram-positive and Gram-negative bacteria.

  5. Computational integration of homolog and pathway gene module expression reveals general stemness signatures.

    Directory of Open Access Journals (Sweden)

    Martina Koeva

    Full Text Available The stemness hypothesis states that all stem cells use common mechanisms to regulate self-renewal and multi-lineage potential. However, gene expression meta-analyses at the single gene level have failed to identify a significant number of genes selectively expressed by a broad range of stem cell types. We hypothesized that stemness may be regulated by modules of homologs. While the expression of any single gene within a module may vary from one stem cell type to the next, it is possible that the expression of the module as a whole is required so that the expression of different, yet functionally-synonymous, homologs is needed in different stem cells. Thus, we developed a computational method to test for stem cell-specific gene expression patterns from a comprehensive collection of 49 murine datasets covering 12 different stem cell types. We identified 40 individual genes and 224 stemness modules with reproducible and specific up-regulation across multiple stem cell types. The stemness modules included families regulating chromatin remodeling, DNA repair, and Wnt signaling. Strikingly, the majority of modules represent evolutionarily related homologs. Moreover, a score based on the discovered modules could accurately distinguish stem cell-like populations from other cell types in both normal and cancer tissues. This scoring system revealed that both mouse and human metastatic populations exhibit higher stemness indices than non-metastatic populations, providing further evidence for a stem cell-driven component underlying the transformation to metastatic disease.

  6. The Arabidopsis thaliana homolog of the helicase RTEL1 plays multiple roles in preserving genome stability.

    Science.gov (United States)

    Recker, Julia; Knoll, Alexander; Puchta, Holger

    2014-12-01

    In humans, mutations in the DNA helicase Regulator of Telomere Elongation Helicase1 (RTEL1) lead to Hoyeraal-Hreidarsson syndrome, a severe, multisystem disorder. Here, we demonstrate that the RTEL1 homolog in Arabidopsis thaliana plays multiple roles in preserving genome stability. RTEL1 suppresses homologous recombination in a pathway parallel to that of the DNA translocase FANCM. Cytological analyses of root meristems indicate that RTEL1 is involved in processing DNA replication intermediates independently from FANCM and the nuclease MUS81. Moreover, RTEL1 is involved in interstrand and intrastrand DNA cross-link repair independently from FANCM and (in intrastrand cross-link repair) parallel to MUS81. RTEL1 contributes to telomere homeostasis; the concurrent loss of RTEL1 and the telomerase TERT leads to rapid, severe telomere shortening, which occurs much more rapidly than it does in the single-mutant line tert, resulting in developmental arrest after four generations. The double mutant rtel1-1 recq4A-4 exhibits massive growth defects, indicating that this RecQ family helicase, which is also involved in the suppression of homologous recombination and the repair of DNA lesions, can partially replace RTEL1 in the processing of DNA intermediates. The requirement for RTEL1 in multiple pathways to preserve genome stability in plants can be explained by its putative role in the destabilization of DNA loop structures, such as D-loops and T-loops. © 2014 American Society of Plant Biologists. All rights reserved.

  7. Resolving RAD51C function in late stages of homologous recombination

    Directory of Open Access Journals (Sweden)

    Kuznetsov Sergey G

    2007-06-01

    Full Text Available Abstract DNA double strand breaks are efficiently repaired by homologous recombination. One of the last steps of this process is resolution of Holliday junctions that are formed at the sites of genetic exchange between homologous DNA. Although various resolvases with Holliday junctions processing activity have been identified in bacteriophages, bacteria and archaebacteria, eukaryotic resolvases have been elusive. Recent biochemical evidence has revealed that RAD51C and XRCC3, members of the RAD51-like protein family, are involved in Holliday junction resolution in mammalian cells. However, purified recombinant RAD51C and XRCC3 proteins have not shown any Holliday junction resolution activity. In addition, these proteins did not reveal the presence of a nuclease domain, which raises doubts about their ability to function as a resolvase. Furthermore, oocytes from infertile Rad51C mutant mice exhibit precocious separation of sister chromatids at metaphase II, a phenotype that reflects a defect in sister chromatid cohesion, not a lack of Holliday junction resolution. Here we discuss a model to explain how a Holliday junction resolution defect can lead to sister chromatid separation in mouse oocytes. We also describe other recent in vitro and in vivo evidence supporting a late role for RAD51C in homologous recombination in mammalian cells, which is likely to be resolution of the Holliday junction.

  8. Physical properties of layered homologous RE-B-C(N) compounds

    International Nuclear Information System (INIS)

    Mori, Takao; Zhang Fuxiang; Leithe-Jasper, Andreas

    2004-01-01

    Physical properties of a series of homologous RE-B-C(N) B 12 cluster compounds REB 17 CN, REB 22 C 2 N, and REB 28.5 C 4 (RE=Er,Ho) were investigated. The structures of the compounds are layer-like along the c-axis, with rare earth and B 6 octahedral layers separated by B 12 icosahedral and C-B-C chain layers whose number increases successively from two B 12 layers for the REB 17 CN compound to four for the REB 28.5 C 4 compound. The rare earth atoms are configured in two triangular flat layers which are stacked on top of one another in AB stacking where the nearest-neighbor rare earth directions are the three atoms forming a triangle in the adjacent layer. The series of homologous compounds exhibit a spin glass transition with T f shifting in correspondence with variations of the basal plane lattice constants, consistent with the magnetic interaction being effective in the basal planes. The isothermal remanent magnetization shows a stretched exponential decay I m (t)∝ exp[-Ct -(1-n) ]. Exponents determined for the different homologous compounds were scaled as a function of T r =T/T f and found to follow the empirical dependency determined for typical spin glasses. It is indicated that a mixture of disorder originating from the partial occupancy of the rare earth sites and frustration of interactions due to the unique configuration is responsible for the manifestation of spin glass transitions in these homologous systems

  9. Homology of normal chains and cohomology of charges

    CERN Document Server

    Pauw, Th De; Pfeffer, W F

    2017-01-01

    The authors consider a category of pairs of compact metric spaces and Lipschitz maps where the pairs satisfy a linearly isoperimetric condition related to the solvability of the Plateau problem with partially free boundary. It includes properly all pairs of compact Lipschitz neighborhood retracts of a large class of Banach spaces. On this category the authors define homology and cohomology functors with real coefficients which satisfy the Eilenberg-Steenrod axioms, but reflect the metric properties of the underlying spaces. As an example they show that the zero-dimensional homology of a space in our category is trivial if and only if the space is path connected by arcs of finite length. The homology and cohomology of a pair are, respectively, locally convex and Banach spaces that are in duality. Ignoring the topological structures, the homology and cohomology extend to all pairs of compact metric spaces. For locally acyclic spaces, the authors establish a natural isomorphism between their cohomology and the �...

  10. Generalized local homology and cohomology for linearly compact modules

    International Nuclear Information System (INIS)

    Tran Tuan Nam

    2006-07-01

    We study generalized local homology for linearly compact modules. By duality, we get some properties of generalized local cohomology modules and extend well-known properties of local cohomology of A. Grothendieck. (author)

  11. On the homology and the cohomology of certain polycyclic groups

    International Nuclear Information System (INIS)

    Majumdar, S.

    1987-10-01

    The homology and the cohomology of infinite non-abelian split extensions of cyclic groups by cyclic groups have been computed through construction of nice free resolutions for these groups. (author). 16 refs

  12. Inhibitory Effect of Berberine on Zeste Homolog 2 (Ezh2 ...

    African Journals Online (AJOL)

    homolog 2 (Ezh2) expressions in KYSE450 human esophageal cancer cells. Methods: ... of the AXL receptor kinase. The results of ... effects of estrogen receptor antagonists on ..... protein EZH2 is involved in progression of prostate cancer.

  13. Matrix factorizations and homological mirror symmetry on the torus

    International Nuclear Information System (INIS)

    Knapp, Johanna; Omer, Harun

    2007-01-01

    We consider matrix factorizations and homological mirror symmetry on the torus T 2 using a Landau-Ginzburg description. We identify the basic matrix factorizations of the Landau-Ginzburg superpotential and compute the full spectrum taking into account the explicit dependence on bulk and boundary moduli. We verify homological mirror symmetry by comparing three-point functions in the A-model and the B-model

  14. Regulation of homologous recombination at telomeres in budding yeast

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine; Lisby, Michael

    2010-01-01

    Homologous recombination is suppressed at normal length telomere sequences. In contrast, telomere recombination is allowed when telomeres erode in the absence of telomerase activity or as a consequence of nucleolytic degradation or incomplete replication. Here, we review the mechanisms that contr...... that contribute to regulating mitotic homologous recombination at telomeres and the role of these mechanisms in signalling short telomeres in the budding yeast Saccharomyces cerevisiae....

  15. Zeroth Poisson Homology, Foliated Cohomology and Perfect Poisson Manifolds

    Science.gov (United States)

    Martínez-Torres, David; Miranda, Eva

    2018-01-01

    We prove that, for compact regular Poisson manifolds, the zeroth homology group is isomorphic to the top foliated cohomology group, and we give some applications. In particular, we show that, for regular unimodular Poisson manifolds, top Poisson and foliated cohomology groups are isomorphic. Inspired by the symplectic setting, we define what a perfect Poisson manifold is. We use these Poisson homology computations to provide families of perfect Poisson manifolds.

  16. Differential effects of NAA and 2,4-D in reducing floret abscission in cestrum (Cestrum elegans) cut flowers are associated with their differential activation of Aux/IAA homologous genes.

    Science.gov (United States)

    Abebie, Bekele; Lers, Amnon; Philosoph-Hadas, Sonia; Goren, Raphael; Riov, Joseph; Meir, Shimon

    2008-01-01

    A previous study showed that the relative effectiveness of 2,4-dichlorophenoxyacetic acid (2,4-D) compared with that of 1-naphthaleneacetic acid (NAA) in reducing floret bud abscission in cestrum (Cestrum elegans) cut flowers was due to its acropetal transport. The aim of the present study was to examine if the differential effect of these auxins on floret abscission is reflected in the expression of Aux/IAA genes in the floret abscission zone (AZ). cDNAs were isolated by PCR-based cloning from the floret AZ of auxin-treated cut flowers. The expression patterns of the cDNAs in various tissues and the effect of indole-3-acetic acid (IAA), applied with or without cycloheximide, on their expression in the floret AZ were examined by northern blot analysis. The regulation of transcript accumulation in the floret AZ in response to NAA or 2,4-D was measured by real-time PCR during auxin pulsing of cut flowers and vase life, concomitantly with floret abscission. Six isolated cDNAs were identified to represent Aux/IAA homologous genes, designated as Cestrum elegans (Ce)-IAA1 to Ce-IAA6. Four Ce-IAA genes were characterized as early auxin-responsive genes (ARGs), and two (Ce-IAA1 and Ce-IAA5) as late ARGs. Only Ce-IAA5 was AZ-specific in floret buds. A temporal regulation of Ce-IAA transcript levels in the floret AZ was found, with 2,4-D inducing higher expression levels than NAA in floret buds. These Ce-IAA expression levels were negatively correlated with floret abscission. The differential transport characteristics of NAA and 2,4-D in cestrum cut flowers were reflected in differential activation of the Ce-IAA genes identified in the floret AZ. Therefore, Aux/IAA genes can be used as molecular markers to measure auxin activity, which reflects free auxin level in the AZ. Two of the identified genes, Ce-IAA1 and Ce-IAA5, may also have a regulatory role in abscission.

  17. Photovoltaic Effect of 2D Homologous Perovskites

    International Nuclear Information System (INIS)

    Jung, Mi-Hee

    2017-01-01

    Highlights: • The mixed perovskite was prepared by exposure of MAI gas on the BAPbI_4 film. • The increased dimensional perovskite shows a smaller band gap than 2D perovskite. • The mixed perovskite system shows the vertical crystal orientation. • The mixed perovskite cell exhibits the higher Jsc and FF than 2D perovskite cell. - Abstract: The controlled growth of mixed dimensional perovskite structures, (C_6H_5CH_2NH_2)(CH_3NH_3)_n_-_1Pb_nI_3_n_+_1, through the introduction of CH_3NH_3I molecule vapor into the two-dimensional perovskite C_6H_5CH_2NH_3PbI_4 structure and its application in photovoltaic devices is reported. The dimensionality of (C_6H_5CH_2NH_2)(CH_3NH_3)_n_-_1Pb_nI_3_n_+_1 is controlled using the exposure time to the CH_3NH_3I vapor on the C_6H_5CH_2NH_3PbI_4 perovskite film. As the stacking of the lead iodide lattice increases, the crystallographic planes of the inorganic perovskite compound exhibit vertical growth in order to facilitate efficient charge transport. Furthermore, the devices have a smaller band gap, which offers broader absorption and the potential to increase the photocurrent density in the solar cell. As a result, the photovoltaic device based on the (C_6H_5CH_2NH_2)(CH_3NH_3)_n_-_1Pb_nI_3_n_+_1 perovskite exhibits a power conversion efficiency of 5.43% with a short circuit current density of 14.49 mA cm"−"2, an open circuit voltage of 0.85 V, and a fill factor of 44.30 for the best power conversion efficiency under AM 1.5G solar irradiation (100 mW cm"−"2), which is significantly higher than the 0.34% of the pure two-dimensional BAPbI_4 perovskite-based solar cell.

  18. Artefacts and the performance of an exhibition

    DEFF Research Database (Denmark)

    Svabo, Connie

    2008-01-01

    The article explores the role of mediating artefacts in children's encounters with a museum of natural history. Using actor network theory it explores how a specific artefact shapes the way users relate to exhibited objects and how the artefact guides users' movements in the exhibition....... The mediated performance of an exhibition is explored through an empirical case....

  19. Affordances and distributed cognition in museum exhibitions

    DEFF Research Database (Denmark)

    Achiam, Marianne; May, Michael; Marandino, Martha

    2014-01-01

    consistent framework. Here, we invoke the notions of affordance and distributed cognition to explain in a coherent way how visitors interact with exhibits and exhibit spaces and make meaning from those interactions, and we exemplify our points using observations of twelve visitors to exhibits at a natural...... history museum. We show how differences in exhibit characteristics give rise to differences in the interpretive strategies used by visitors in their meaning-making process, and conclude by discussing how the notions of affordance and distributed cognition can be used in an exhibit design perspective....

  20. The assembly of MreB, a prokaryotic homolog of actin.

    Science.gov (United States)

    Esue, Osigwe; Cordero, Maria; Wirtz, Denis; Tseng, Yiider

    2005-01-28

    MreB, a major component of the bacterial cytoskeleton, exhibits high structural homology to its eukaryotic counterpart actin. Live cell microscopy studies suggest that MreB molecules organize into large filamentous spirals that support the cell membrane and play a key shape-determining function. However, the basic properties of MreB filament assembly remain unknown. Here, we studied the assembly of Thermotoga maritima MreB triggered by ATP in vitro and compared it to the well-studied assembly of actin. These studies show that MreB filament ultrastructure and polymerization depend crucially on temperature as well as the ions present on solution. At the optimal growth temperature of T. maritima, MreB assembly proceeded much faster than that of actin, without nucleation (or nucleation is highly favorable and fast) and with little or no contribution from filament end-to-end annealing. MreB exhibited rates of ATP hydrolysis and phosphate release similar to that of F-actin, however, with a critical concentration of approximately 3 nm, which is approximately 100-fold lower than that of actin. Furthermore, MreB assembled into filamentous bundles that have the ability to spontaneously form ring-like structures without auxiliary proteins. These findings suggest that despite high structural homology, MreB and actin display significantly different assembly properties.

  1. RPA homologs and ssDNA processing during meiotic recombination.

    Science.gov (United States)

    Ribeiro, Jonathan; Abby, Emilie; Livera, Gabriel; Martini, Emmanuelle

    2016-06-01

    Meiotic homologous recombination is a specialized process that involves homologous chromosome pairing and strand exchange to guarantee proper chromosome segregation and genetic diversity. The formation and repair of DNA double-strand breaks (DSBs) during meiotic recombination differs from those during mitotic recombination in that the homologous chromosome rather than the sister chromatid is the preferred repair template. The processing of single-stranded DNA (ssDNA) formed on intermediate recombination structures is central to driving the specific outcomes of DSB repair during meiosis. Replication protein A (RPA) is the main ssDNA-binding protein complex involved in DNA metabolism. However, the existence of RPA orthologs in plants and the recent discovery of meiosis specific with OB domains (MEIOB), a widely conserved meiosis-specific RPA1 paralog, strongly suggest that multiple RPA complexes evolved and specialized to subdivide their roles during DNA metabolism. Here we review ssDNA formation and maturation during mitotic and meiotic recombination underlying the meiotic specific features. We describe and discuss the existence and properties of MEIOB and multiple RPA subunits in plants and highlight how they can provide meiosis-specific fates to ssDNA processing during homologous recombination. Understanding the functions of these RPA homologs and how they interact with the canonical RPA subunits is of major interest in the fields of meiosis and DNA repair.

  2. The OGCleaner: filtering false-positive homology clusters.

    Science.gov (United States)

    Fujimoto, M Stanley; Suvorov, Anton; Jensen, Nicholas O; Clement, Mark J; Snell, Quinn; Bybee, Seth M

    2017-01-01

    Detecting homologous sequences in organisms is an essential step in protein structure and function prediction, gene annotation and phylogenetic tree construction. Heuristic methods are often employed for quality control of putative homology clusters. These heuristics, however, usually only apply to pairwise sequence comparison and do not examine clusters as a whole. We present the Orthology Group Cleaner (the OGCleaner), a tool designed for filtering putative orthology groups as homology or non-homology clusters by considering all sequences in a cluster. The OGCleaner relies on high-quality orthologous groups identified in OrthoDB to train machine learning algorithms that are able to distinguish between true-positive and false-positive homology groups. This package aims to improve the quality of phylogenetic tree construction especially in instances of lower-quality transcriptome assemblies. https://github.com/byucsl/ogcleaner CONTACT: sfujimoto@gmail.comSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Primary homologies of the circumorbital bones of snakes.

    Science.gov (United States)

    Palci, Alessandro; Caldwell, Michael W

    2013-09-01

    Some snakes have two circumorbital ossifications that in the current literature are usually referred to as the postorbital and supraorbital. We review the arguments that have been proposed to justify this interpretation and provide counter-arguments that reject those conjectures of primary homology based on the observation of 32 species of lizards and 81 species of snakes (both extant and fossil). We present similarity arguments, both topological and structural, for reinterpretation of the primary homologies of the dorsal and posterior orbital ossifications of snakes. Applying the test of similarity, we conclude that the posterior orbital ossification of snakes is topologically consistent as the homolog of the lacertilian jugal, and that the dorsal orbital ossification present in some snakes (e.g., pythons, Loxocemus, and Calabaria) is the homolog of the lacertilian postfrontal. We therefore propose that the terms postorbital and supraorbital should be abandoned as reference language for the circumorbital bones of snakes, and be replaced with the terms jugal and postfrontal, respectively. The primary homology claim for the snake "postorbital" fails the test of similarity, while the term "supraorbital" is an unnecessary and inaccurate application of the concept of a neomorphic ossification, for an element that passes the test of similarity as a postfrontal. This reinterpretation of the circumorbital bones of snakes is bound to have important repercussions for future phylogenetic analyses and consequently for our understanding of the origin and evolution of snakes. Copyright © 2013 Wiley Periodicals, Inc.

  4. Investigating Design Research Landscapes through Exhibition

    DEFF Research Database (Denmark)

    Jönsson, Li; Hansen, Flemming Tvede; Mäkelä, Maarit

    2013-01-01

    What characterizes a design research exhibition compared to a traditional design and art exhibition? How do you show the very materialities of the design experiments as a means for communicating knowledge of research and of practice? How do you present, review and utilize such an exhibition......? With those questions in mind, the intention and challenge for the Nordes 2013 Design Research Exhibition was to expand on current notions of staging research enquires in design research conference contexts. Artefacts, installations, performances, and other materialities that relate to the theme...... of the conference - Experiments in Design Research – were displayed as tools to express and communicate different design research enquires. Through this paper we will describe the Nordes exhibition as a specific case that renders questions visible in relation to how to utilize a design research exhibition...

  5. Superconductive microstrip exhibiting negative differential resistivity

    International Nuclear Information System (INIS)

    Huebener, R.P.; Gallus, D.E.

    1975-01-01

    A device capable of exhibiting negative differential electrical resistivity over a range of values of current and voltage is formed by vapor-depositing a thin layer of a material capable of exhibiting superconductivity on an insulating substrate, establishing electrical connections at opposite ends of the deposited strip, and cooling the alloy into its superconducting range. The device will exhibit negative differential resistivity when biased in the current-induced resistive state

  6. The tumor suppressor homolog in fission yeast, myh1+, displays a strong interaction with the checkpoint gene rad1+

    International Nuclear Information System (INIS)

    Jansson, Kristina; Warringer, Jonas; Farewell, Anne; Park, Han-Oh; Hoe, Kwang-Lae; Kim, Dong-Uk; Hayles, Jacqueline; Sunnerhagen, Per

    2008-01-01

    The DNA glycosylase MutY is strongly conserved in evolution, and homologs are found in most eukaryotes and prokaryotes examined. This protein is implicated in repair of oxidative DNA damage, in particular adenine mispaired opposite 7,8-dihydro-8-oxoguanine. Previous investigations in Escherichia coli, fission yeast, and mammalian cells show an association of mutations in MutY homologs with a mutator phenotype and carcinogenesis. Eukaryotic MutY homologs physically associate with several proteins with a role in replication, DNA repair, and checkpoint signaling, specifically the trimeric 9-1-1 complex. In a genetic investigation of the fission yeast MutY homolog, myh1 + , we show that the myh1 mutation confers a moderately increased UV sensitivity alone and in combination with mutations in several DNA repair genes. The myh1 rad1, and to a lesser degree myh1 rad9, double mutants display a synthetic interaction resulting in enhanced sensitivity to DNA damaging agents and hydroxyurea. UV irradiation of myh1 rad1 double mutants results in severe chromosome segregation defects and visible DNA fragmentation, and a failure to activate the checkpoint. Additionally, myh1 rad1 double mutants exhibit morphological defects in the absence of DNA damaging agents. We also found a moderate suppression of the slow growth and UV sensitivity of rhp51 mutants by the myh1 mutation. Our results implicate fission yeast Myh1 in repair of a wider range of DNA damage than previously thought, and functionally link it to the checkpoint pathway

  7. Cloning of cDNAs that encode human mast cell carboxypeptidase A, and comparison of the protein with mouse mast cell carboxypeptidase A and rat pancreatic carboxypeptidases

    International Nuclear Information System (INIS)

    Reynolds, D.S.; Gurley, D.S.; Stevens, R.L.; Austen, K.F.; Serafin, W.E.; Sugarbaker, D.J.

    1989-01-01

    Human skin and lung mast cells and rodent peritoneal cells contain a carboxypeptidase in their secretory granules. The authors have screened human lung cDNA libraries with a mouse mast cell carboxypeptidase A (MC-CPA) cDNA probe to isolate a near-full-length cDNA that encodes human MC-CPA. The 5' end of the human MC-CPA transcript was defined by direct mRNA sequencing and by isolation and partial sequencing of the human MC-CPA gene. Human MC-CPA is predicted to be translated as a 417 amino acid preproenzyme which includes a 15 amino acid signal peptide and a 94-amino acid activation peptide. The mature human MC-CPA enzyme has a predicted size of 36.1 kDa, a net positive charge of 16 at neutral pH, and 86% amino acid sequence identity with mouse MC-CPA. DNA blot analyses showed that human MC-CPA mRNA is transcribed from a single locus in the human genome. Comparison of the human MC-CPA with mouse MC-CPA and with three rat pancreatic carboxypeptidases shows that these enzymes are encoded by distinct but homologous genes

  8. [Analysis of DNA-DNA homologies in obligate methylotrophic bacteria].

    Science.gov (United States)

    Doronina, N V; Govorukhina, N I; Lysenko, A M; Trotsenko, Iu A

    1988-01-01

    The genotypic affinity of 19 bacterial strains obligately dependent on methanol or methylamine as carbon and energy sources was studied by techniques of molecular DNA hybridization. The high homology level (35-88%) between motile strain Methylophilus methanolovorus V-1447D and nonmotile strain Methylobacillus sp. VSB-792 as well as other motile strains (Pseudomonas methanolica ATCC 21704, Methylomonas methanolica NRRL 5458, Pseudomonas sp. W6, strain A3) indicates that all of them belong to one genus. Rather high level of homology (62-63%) was found between Methylobacillus glycogenes ATCC 29475 and Pseudomonas insueta ATCC 21276 and strain G-10. The motile strain Methylophilus methylotrophus NCIB 10515 has a low homology (below 20%) to other of the studied obligate methylobacteria. Therefore, at least two genetically different genera of obligate methylobacteria can be distinguished, namely Methylophilus and Methylobacillus, the latter being represented by both motile and nonmotile forms.

  9. Khovanov homology for virtual knots with arbitrary coefficients

    International Nuclear Information System (INIS)

    Manturov, Vassily O

    2007-01-01

    The Khovanov homology theory over an arbitrary coefficient ring is extended to the case of virtual knots. We introduce a complex which is well-defined in the virtual case and is homotopy equivalent to the original Khovanov complex in the classical case. Unlike Khovanov's original construction, our definition of the complex does not use any additional prescription of signs to the edges of a cube. Moreover, our method enables us to construct a Khovanov homology theory for 'twisted virtual knots' in the sense of Bourgoin and Viro (including knots in three-dimensional projective space). We generalize a number of results of Khovanov homology theory (the Wehrli complex, minimality problems, Frobenius extensions) to virtual knots with non-orientable atoms

  10. Homology groups for particles on one-connected graphs

    Science.gov (United States)

    MaciÄ Żek, Tomasz; Sawicki, Adam

    2017-06-01

    We present a mathematical framework for describing the topology of configuration spaces for particles on one-connected graphs. In particular, we compute the homology groups over integers for different classes of one-connected graphs. Our approach is based on some fundamental combinatorial properties of the configuration spaces, Mayer-Vietoris sequences for different parts of configuration spaces, and some limited use of discrete Morse theory. As one of the results, we derive the closed-form formulae for ranks of the homology groups for indistinguishable particles on tree graphs. We also give a detailed discussion of the second homology group of the configuration space of both distinguishable and indistinguishable particles. Our motivation is the search for new kinds of quantum statistics.

  11. A Heuristic for Improving Transmedia Exhibition Experience

    DEFF Research Database (Denmark)

    Selvadurai, Vashanth; Rosenstand, Claus Andreas Foss

    2017-01-01

    in the scientific field of designing transmedia experience in an exhibition context that links the pre- and post-activities to the actual visit (during-activities). The result of this study is a preliminary heuristic for establishing a relation between the platform and content complexity in transmedia exhibitions....

  12. Memory and Mourning: An Exhibit History

    Science.gov (United States)

    Eberle, Scott G.

    2005-01-01

    Mounted by the Strong Museum in Rochester, New York, in 1993, and traveling nationally thereafter, the exhibit Memory and Mourning provided historical and contemporary perspectives to help museum guests explore their own reactions to loss and grief. In the process the exhibit's development team encountered a range of philosophical, historical,…

  13. Let's play game exhibitions : A curator's perspective

    NARCIS (Netherlands)

    de Vos, Jesse; Glas, M.A.J.|info:eu-repo/dai/nl/330981447; van Vught, J.F.|info:eu-repo/dai/nl/413532682

    2017-01-01

    The Netherlands Institute for Sound and Vision is home to The Experience, a museum exhibiting the history of media in the Netherlands. For ten months in 2016 and 2017, The Experience hosted a temporary exhibition entitled Let’s YouTube . During the Let’s YouTube game month, we programmed a ten-day

  14. Science Fiction Exhibits as STEM Gateways

    Science.gov (United States)

    Robie, Samantha

    Women continue to hold less than a quarter of all STEM jobs in the United States, prompting many museums to develop programs and exhibits with the express goal of interesting young girls in scientific fields. At the same time, a number of recent museum exhibits have harnessed the popularity of pop culture and science fiction in order to interest general audiences in STEM subject matter, as well as using the exhibits as springboards to expand or shift mission goals and focus. Because science fiction appears to be successful at raising interest in STEM fields, it may be an effective way to garner the interest of young girls in STEM in particular. This research seeks to describe the ways in which museums are currently using science fiction exhibits to interest young girls in STEM fields and careers. Research focused on four institutions across the country hosting three separate exhibits, and included staff interviews and content analysis of exhibit descriptions, promotional materials, a summative evaluation and supplementary exhibit productions. In some ways, science fiction exhibits do serve young girls, primarily through the inclusion of female role models, staff awareness, and prototype testing to ensure interactives are attractive to girls as well as to boys. However, STEM appears to be underutilized, which may be partly due to a concern within the field that the outcome of targeting a specific gender could be construed as "stereotyping".

  15. Khovanov-Rozansky Graph Homology and Composition Product

    DEFF Research Database (Denmark)

    Wagner, Emmanuel

    2008-01-01

    In analogy with a recursive formula for the HOMFLY-PT polynomial of links given by Jaeger, we give a recursive formula for the graph polynomial introduced by Kauffman and Vogel. We show how this formula extends to the Khovanov–Rozansky graph homology.......In analogy with a recursive formula for the HOMFLY-PT polynomial of links given by Jaeger, we give a recursive formula for the graph polynomial introduced by Kauffman and Vogel. We show how this formula extends to the Khovanov–Rozansky graph homology....

  16. Macdonald operators and homological invariants of the colored Hopf link

    International Nuclear Information System (INIS)

    Awata, Hidetoshi; Kanno, Hiroaki

    2011-01-01

    Using a power sum (boson) realization for the Macdonald operators, we investigate the Gukov, Iqbal, Kozcaz and Vafa (GIKV) proposal for the homological invariants of the colored Hopf link, which include Khovanov-Rozansky homology as a special case. We prove the polynomiality of the invariants obtained by GIKV's proposal for arbitrary representations. We derive a closed formula of the invariants of the colored Hopf link for antisymmetric representations. We argue that a little amendment of GIKV's proposal is required to make all the coefficients of the polynomial non-negative integers. (paper)

  17. The Culture of Exhibitions and Conservation

    Directory of Open Access Journals (Sweden)

    Dimitrios Doumas

    2013-11-01

    Full Text Available The article reflects on temporary exhibitions from a theoretical as well as practical perspective. Regarded as a particularly effective mass-communication medium, exhibitions have a dual nature: they are scholarly undertakings, bringing off a curator’s vision and, simultaneously, they are projects with economic implications that need to be well managed and administered. The role of conservation in the making of temporary exhibitions, either in-house or touring, is here discussed in relation to how work is planned and prioritized as well as how time is managed and staff is allocated. Reference to weaknesses that lessen the crucial input of conservation in the decision-making process is also made. Much of the debate, which focuses on art exhibitions, concerns practicalities encountered in a private museum that extend from the very early stages of selecting objects for display to the mounting of an exhibition.

  18. Holland at CERN – Industrial exhibition

    CERN Multimedia

    GS Department

    2010-01-01

    Sponsored by EVD, an agency of the Dutch Ministry of the Economy From 8 to 11 November 2010 Industrial Exhibition Administration Building Bldg. 61 9-00 - 17-30 Twenty seven companies will present their latest technology at the industrial exhibition "Holland at CERN". Dutch industry will exhibit products and technologies which are related to the field of particle physics. Individual interviews will take place directly at the stands in the Main Building. The firms will contact relevant users/technicians but any user wishing to make contact with a particular firm is welcome to use the contact details which are available from each departmental secretariat or at the following URL: http://gs-dep.web.cern.ch/gs-dep/groups/sem/ls/Industrial_Exhibitions.htm#Industrial_exhibitions You will find the list of exhibitors below. LIST OF EXHIBITORS: Schelde Exotech Vernooy BV Triumph Group INCAA Computers DeMaCo Holland bv TNO Science & Industry Janssen Precision Engi...

  19. A mini-exhibition with maximum content

    CERN Multimedia

    Laëtitia Pedroso

    2011-01-01

    The University of Budapest has been hosting a CERN mini-exhibition since 8 May. While smaller than the main travelling exhibition it has a number of major advantages: its compact design alleviates transport difficulties and makes it easier to find suitable venues in the Member States. Its content can be updated almost instantaneously and it will become even more interactive and high-tech as time goes by.   The exhibition on display in Budapest. The purpose of CERN's new mini-exhibition is to be more interactive and easier to install. Due to its size, the main travelling exhibition cannot be moved around quickly, which is why it stays in the same country for 4 to 6 months. But this means a long waiting list for the other Member States. To solve this problem, the Education Group has designed a new exhibition, which is smaller and thus easier to install. Smaller maybe, but no less rich in content, as the new exhibition conveys exactly the same messages as its larger counterpart. However, in the slimm...

  20. Topological Hochschild homology and the Bass trace conjecture

    DEFF Research Database (Denmark)

    Berrick, A. J.; Hesselholt, Lars

    2015-01-01

    We use the methods of topological Hochschild homology to shed new light on groups satisfying the Bass trace conjecture. Factorization of the Hattori–Stallings rank map through the Bökstedt–Hsiang–Madsen cyclotomic trace map leads to Linnell's restriction on such groups. As a new consequence...

  1. The homological content of the Jones representations at $q = -1$

    DEFF Research Database (Denmark)

    Egsgaard, Jens Kristian; Fuglede Jørgensen, Søren

    We generalize a discovery of Kasahara and show that the Jones representations of braid groups, when evaluated at $q = -1$, are related to the action on homology of a branched double cover of the underlying punctured disk. As an application, we prove for a large family of pseudo-Anosov mapping...

  2. Topological quantum information, virtual Jones polynomials and Khovanov homology

    International Nuclear Information System (INIS)

    Kauffman, Louis H

    2011-01-01

    In this paper, we give a quantum statistical interpretation of the bracket polynomial state sum 〈K〉, the Jones polynomial V K (t) and virtual knot theory versions of the Jones polynomial, including the arrow polynomial. We use these quantum mechanical interpretations to give new quantum algorithms for these Jones polynomials. In those cases where the Khovanov homology is defined, the Hilbert space C(K) of our model is isomorphic with the chain complex for Khovanov homology with coefficients in the complex numbers. There is a natural unitary transformation U:C(K) → C(K) such that 〈K〉 = Trace(U), where 〈K〉 denotes the evaluation of the state sum model for the corresponding polynomial. We show that for the Khovanov boundary operator ∂:C(K) → C(K), we have the relationship ∂U + U∂ = 0. Consequently, the operator U acts on the Khovanov homology, and we obtain a direct relationship between the Khovanov homology and this quantum algorithm for the Jones polynomial. (paper)

  3. Homology of the open moduli space of curves

    DEFF Research Database (Denmark)

    Madsen, Ib Henning

    2012-01-01

    This is a survey on the proof of a generalized version of the Mumford conjecture obtained in joint work with M. Weiss stating that a certain map between some classifying spaces which a priori have different natures induces an isomorphism at the level of integral homology. We also discuss our proo...

  4. On the Cogosvili functor generated by a homology

    International Nuclear Information System (INIS)

    Abd El-Satter, A. Dabbour; Mahmoud, S.

    1991-09-01

    In the present work we discuss the Cogosvili functor generated by a homology, and study the construction of the corresponding groups and their induced homomorphisms. Moreover, we investigate the properties of this functor and prove that the set of such functors are isomorphic to the Bauer homotopy theory. (author). 19 refs

  5. Multiresolution persistent homology for excessively large biomolecular datasets

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Kelin; Zhao, Zhixiong [Department of Mathematics, Michigan State University, East Lansing, Michigan 48824 (United States); Wei, Guo-Wei, E-mail: wei@math.msu.edu [Department of Mathematics, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824 (United States)

    2015-10-07

    Although persistent homology has emerged as a promising tool for the topological simplification of complex data, it is computationally intractable for large datasets. We introduce multiresolution persistent homology to handle excessively large datasets. We match the resolution with the scale of interest so as to represent large scale datasets with appropriate resolution. We utilize flexibility-rigidity index to access the topological connectivity of the data set and define a rigidity density for the filtration analysis. By appropriately tuning the resolution of the rigidity density, we are able to focus the topological lens on the scale of interest. The proposed multiresolution topological analysis is validated by a hexagonal fractal image which has three distinct scales. We further demonstrate the proposed method for extracting topological fingerprints from DNA molecules. In particular, the topological persistence of a virus capsid with 273 780 atoms is successfully analyzed which would otherwise be inaccessible to the normal point cloud method and unreliable by using coarse-grained multiscale persistent homology. The proposed method has also been successfully applied to the protein domain classification, which is the first time that persistent homology is used for practical protein domain analysis, to our knowledge. The proposed multiresolution topological method has potential applications in arbitrary data sets, such as social networks, biological networks, and graphs.

  6. Human Fanconi anemia monoubiquitination pathway promotes homologous DNA repair.

    Science.gov (United States)

    Nakanishi, Koji; Yang, Yun-Gui; Pierce, Andrew J; Taniguchi, Toshiyasu; Digweed, Martin; D'Andrea, Alan D; Wang, Zhao-Qi; Jasin, Maria

    2005-01-25

    Fanconi anemia (FA) is a recessive disorder characterized by congenital abnormalities, progressive bone-marrow failure, and cancer susceptibility. Cells from FA patients are hypersensitive to agents that produce DNA crosslinks and, after treatment with these agents, have pronounced chromosome breakage and other cytogenetic abnormalities. Eight FANC genes have been cloned, and the encoded proteins interact in a common cellular pathway. DNA-damaging agents activate the monoubiquitination of FANCD2, resulting in its targeting to nuclear foci that also contain BRCA1 and BRCA2/FANCD1, proteins involved in homology-directed DNA repair. Given the interaction of the FANC proteins with BRCA1 and BRCA2, we tested whether cells from FA patients (groups A, G, and D2) and mouse Fanca-/- cells with a targeted mutation are impaired for this repair pathway. We find that both the upstream (FANCA and FANCG) and downstream (FANCD2) FA pathway components promote homology-directed repair of chromosomal double-strand breaks (DSBs). The FANCD2 monoubiquitination site is critical for normal levels of repair, whereas the ATM phosphorylation site is not. The defect in these cells, however, is mild, differentiating them from BRCA1 and BRCA2 mutant cells. Surprisingly, we provide evidence that these proteins, like BRCA1 but unlike BRCA2, promote a second DSB repair pathway involving homology, i.e., single-strand annealing. These results suggest an early role for the FANC proteins in homologous DSB repair pathway choice.

  7. France at CERN – Industrial exhibition

    CERN Multimedia

    FP Department

    2012-01-01

    Industrial Exhibition Administration Building Bldg 61 – 1st Floor Tuesday 27 March: 9 a.m. – 5.30 p.m. Wednesday 28 March: 9 a.m. – 2 p.m.   About thirty French companies are presenting their latest technological advances during the industrial exhibition "France at CERN", featuring products and technologies specifically related to CERN activities. Individual B2B meetings can be organized with the sales and technical representatives of participating firms and will take place at either the companies’ exhibition stands or in conference rooms in the Main Building. Individuals wishing to make contact with one or more companies must use the contact details available from each secretariat of department or by using this link. B2B meetings will be coordinated by UBIFRANCE. You will also find the list of exhibiting and participating companies online here. This event is sponsored by the French subsidiary of RS Components, the most important distri...

  8. High Quality Virtual Reality for Architectural Exhibitions

    DEFF Research Database (Denmark)

    Kreutzberg, Anette

    2016-01-01

    This paper will summarise the findings from creating and implementing a visually high quality Virtual Reality (VR) experiment as part of an international architecture exhibition. It was the aim to represent the architectural spatial qualities as well as the atmosphere created from combining natural...... and artificial lighting in a prominent not yet built project. The outcome is twofold: Findings concerning the integration of VR in an exhibition space and findings concerning the experience of the virtual space itself. In the exhibition, an important aspect was the unmanned exhibition space, requiring the VR...... experience to be self-explanatory. Observations of different visitor reactions to the unmanned VR experience compared with visitor reactions at guided tours with personal instructions are evaluated. Data on perception of realism, spatial quality and light in the VR model were collected with qualitative...

  9. Medan Convention & Exhibition Center (Arsitektur Ekspresionisme)

    OpenAIRE

    Iskandar, Nurul Auni

    2015-01-01

    Medan is one of the third largest city in Indonesia, which is currently being developed, and a city with lots of activities. In the city of Medan has a high investment opportunities for a convention, because of its strategic position in Southeast Asia and also supported by the facility and the potential for tourism in North Sumatra, Medan city has the potential for industrial MICE (Meeting, Incentive, Conference, Exhibition). The construction of Medan Convention & Exhibition Cente...

  10. The presentation of energy topics at exhibitions

    International Nuclear Information System (INIS)

    Moergeli, H.P.

    1984-01-01

    The author examines the problems confronting an electricity supply company when trying to communicate its energy policy to the general public at exhibitions and fairs. The company has to convey a message of reliable power supplies, increasing demand, the advantages of nuclear energy, the safe storage of radioactive waste and the need for new generating plants. The author describes some of the displays being used to attract the public to the Bern Power Stations stand at the Bern Exhibition 1984. (R.S.)

  11. An Astrobiology Microbes Exhibit and Education Module

    Science.gov (United States)

    Lindstrom, Marilyn M.; Allen, Jaclyn S.; Stocco, Karen; Tobola, Kay; Olendzenski, Lorraine

    2001-01-01

    Telling the story of NASA-sponsored scientific research to the public in exhibits is best done by partnerships of scientists and museum professionals. Likewise, preparing classroom activities and training teachers to use them should be done by teams of teachers and scientists. Here we describe how we used such partnerships to develop a new astrobiology augmentation to the Microbes! traveling exhibit and a companion education module. "Additional information is contained in the original extended abstract."

  12. Protein backbone angle restraints from searching a database for chemical shift and sequence homology

    Energy Technology Data Exchange (ETDEWEB)

    Cornilescu, Gabriel; Delaglio, Frank; Bax, Ad [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)

    1999-03-15

    Chemical shifts of backbone atoms in proteins are exquisitely sensitive to local conformation, and homologous proteins show quite similar patterns of secondary chemical shifts. The inverse of this relation is used to search a database for triplets of adjacent residues with secondary chemical shifts and sequence similarity which provide the best match to the query triplet of interest. The database contains 13C{alpha}, 13C{beta}, 13C', 1H{alpha} and 15N chemical shifts for 20 proteins for which a high resolution X-ray structure is available. The computer program TALOS was developed to search this database for strings of residues with chemical shift and residue type homology. The relative importance of the weighting factors attached to the secondary chemical shifts of the five types of resonances relative to that of sequence similarity was optimized empirically. TALOS yields the 10 triplets which have the closest similarity in secondary chemical shift and amino acid sequence to those of the query sequence. If the central residues in these 10 triplets exhibit similar {phi} and {psi} backbone angles, their averages can reliably be used as angular restraints for the protein whose structure is being studied. Tests carried out for proteins of known structure indicate that the root-mean-square difference (rmsd) between the output of TALOS and the X-ray derived backbone angles is about 15 deg. Approximately 3% of the predictions made by TALOS are found to be in error.

  13. Systematic trends in photonic reagent induced reactions in a homologous chemical family.

    Science.gov (United States)

    Tibbetts, Katharine Moore; Xing, Xi; Rabitz, Herschel

    2013-08-29

    The growing use of ultrafast laser pulses to induce chemical reactions prompts consideration of these pulses as "photonic reagents" in analogy to chemical reagents. This work explores the prospect that photonic reagents may affect systematic trends in dissociative ionization reactions of a homologous family of halomethanes, much as systematic outcomes are often observed for reactions between homologous families of chemical reagents and chemical substrates. The experiments in this work with photonic reagents of varying pulse energy and linear spectral chirp reveal systematic correlations between observable ion yields and the following set of natural variables describing the substrate molecules: the ionization energy of the parent molecule, the appearance energy of each fragment ion, and the relative strength of carbon-halogen bonds in molecules containing two different halogens. The results suggest that reactions induced by photonic reagents exhibit systematic behavior analogous to that observed in reactions driven by chemical reagents, which provides a basis to consider empirical "rules" for predicting the outcomes of photonic reagent induced reactions.

  14. A homologous radioimmunoassay for canine prolactin: plasma levels huring the reproductive cycle

    International Nuclear Information System (INIS)

    Coster, R. De; Beerens, D.; Mey, J. De; Beckers, J.-F.

    1983-01-01

    A method is described for the purification of canine prolactin, involving preparative isoelectrofocusing. Canine prolactin has a molecular weight of 23 000 daltons, an isoelectric point of 5.7 and exhibits a high degree of homogeneity in polyacrylamide gels stained by means of a silver method. A specific, homologous radioimmunoassay is described using the Bolton-Hunter method for preparation of the labelled ligand, with a sensitivity of 0.1 ng/tube. Basal plasma prolactin levels of 2-4 ng/ml obtained through the oestrous cycle remained fairly constant but a rise of 9 ng/ml was found at the end of dioestrus in non-pregnant bitches. Level also rose 30 days after mating to reach a peak of about 50 ng/ml near parturition and during early lactation. (author)

  15. Turning energy around: an interactive exhibition experience

    Directory of Open Access Journals (Sweden)

    Sarah Kellberg

    2018-05-01

    Full Text Available A transition from the fossil-fuel driven to a sustainable energy system is an enormous global challenge: climate change and finite resources require countries all over the world to change their way of producing, transporting and using energy. The Energiewende (energy transition will require major changes in the current energy supply system in Germany – but also worldwide. These changes will not only affect the technical sector but will also include ecological questions, social issues and political matters. Whether any transition is going to favour large scale solutions or decentralised technologies depends on local situations and global interconnections, and above all on a democratic process. Hence energy transition succeeds or fails with the acceptance and participation of society. To deal with this overwhelmingly complex topic and its multi-layered dependencies, the Deutsches Museum has designed an exhibition providing visitors with background knowledge about the necessities and challenges of energy transition, unpicking the links between the different technical, economic and social challenges. The exhibition accomplishes the task with an engaging and facilitating approach while taking into account the highly emotive aspects of energy transition as a societal issue. This paper presents the concept of the travelling exhibition energie.wenden, relating it to the Deutsches Museum´s tradition of exhibitions as well as to the challenge of how to deal with socio-scientific topics in scientific exhibitions.

  16. CERN exhibition a big hit in Bulgaria

    CERN Multimedia

    2005-01-01

    The first CERN exhibition in Bulgaria attracted many visitors. In the first ever CERN exhibition to be held in Bulgaria, over 1,400 visitors, many of them students and young physicists, visited the 10-day event in Sofia. The CERN mini-exhibition took place at the National Earth and Mankind Museum between 8 and 17 November. Permanently staffed by young physicists from Sofia University, there were exhibits on display about research activities at CERN, as well as four additional posters describing Bulgaria's participation. The inauguration took place on the morning of 8 November in the presence of the Vice-Minister for Science and Education, Mrs. Vanya Dobreva, and some 200 guests. A series of short speeches were followed by a visit to the exhibition. CERN's representative at the event, Ray Lewis, was then asked by Professor Matey Mateev, President of the Union of Physicists in Bulgaria, to say a few words on behalf of the Organization. Numerous journalists were also present at the inauguration. A painting enti...

  17. Education or business? - exhibition of human corpses

    Directory of Open Access Journals (Sweden)

    Grzegorz Wróbel

    2017-09-01

    Full Text Available Exhibition "BODY WORLDS" which are presented exhibits of human remains are presented all over the world and are a major problem for the modern man, as presented on the preparations of the human not only serve scientific research, are not transferred to the medical schools to educate future doctors, but they were made available to the general public in the form of commercial and ambiguous. The aim of this study was to assess the ethical commercialization of human corpses "BODY WORLDS" exhibitions. Individual approach to the problems presented the dignity and value of human remains after death, of course, strongly related to the professed worldview. In the exhibits can be seen in both the scientific interest anatomical structures, as well as desecrated human remains or beautiful by its functional perfection of the body, understood also in terms of art. The question of ethics determines the right to decide for themselves, on the other hand, allows you to protect bodily integrity even after death. "BODY WORLDS" exhibition goes for the moral and ethical boundaries. In terms of people Gunther von Hagens for plastination of human remains which became a very profitable business, and its current activities defined as "plastination business" should be firmly said about the lack of moral principles.

  18. The exploration of the exhibition informatization

    Science.gov (United States)

    Zhang, Jiankang

    2017-06-01

    The construction and management of exhibition informatization is the main task and choke point during the process of Chinese exhibition industry’s transformation and promotion. There are three key points expected to realize a breakthrough during the construction of Chinese exhibition informatization, and the three aspects respectively are adopting service outsourcing to construct and maintain the database, adopting advanced chest card technology to collect various kinds of information, developing statistics analysis to maintain good cutomer relations. The success of Chinese exhibition informatization mainly calls for mature suppliers who can provide construction and maintenance of database, the proven technology, a sense of data security, advanced chest card technology, the ability of data mining and analysis and the ability to improve the exhibition service basing on the commercial information got from the data analysis. Several data security measures are expected to apply during the process of system developing, including the measures of the terminal data security, the internet data security, the media data security, the storage data security and the application data security. The informatization of this process is based on the chest card designing. At present, there are several types of chest card technology: bar code chest card; two-dimension code card; magnetic stripe chest card; smart-chip chest card. The information got from the exhibition data will help the organizers to make relevant service strategies, quantify the accumulated indexes of the customers, and improve the level of the customer’s satisfaction and loyalty, what’s more, the information can also provide more additional services like the commercial trips, VIP ceremonial reception.

  19. Exhibits in libraries a practical guide

    CERN Document Server

    Brown, Mary E

    2005-01-01

    "Ccomprehensive...detailed"--Booklist; "thoroughly reseached...highly recommended"--Journal of Access Services. Library exhibits are more than entertainment for patrons. They can inspire and educate, stimulate an interest that can be explored in a book, or attract visitors who otherwise wouldn't stop by. Displays are also an opportunity for a library to put its creative foot forward or help patrons navigate the facility itself. This comprehensive "how-to" includes everything a librarian or staff member needs to know to put on an exhibit, from hatching ideas to evaluating the end result. Illustrations and photographs show practical methods of planning, labeling and displaying.

  20. Intersection spaces, spatial homology truncation, and string theory

    CERN Document Server

    Banagl, Markus

    2010-01-01

    Intersection cohomology assigns groups which satisfy a generalized form of Poincaré duality over the rationals to a stratified singular space. The present monograph introduces a method that assigns to certain classes of stratified spaces cell complexes, called intersection spaces, whose ordinary rational homology satisfies generalized Poincaré duality. The cornerstone of the method is a process of spatial homology truncation, whose functoriality properties are analyzed in detail. The material on truncation is autonomous and may be of independent interest to homotopy theorists. The cohomology of intersection spaces is not isomorphic to intersection cohomology and possesses algebraic features such as perversity-internal cup-products and cohomology operations that are not generally available for intersection cohomology. A mirror-symmetric interpretation, as well as applications to string theory concerning massless D-branes arising in type IIB theory during a Calabi-Yau conifold transition, are discussed.

  1. A homology sound-based algorithm for speech signal interference

    Science.gov (United States)

    Jiang, Yi-jiao; Chen, Hou-jin; Li, Ju-peng; Zhang, Zhan-song

    2015-12-01

    Aiming at secure analog speech communication, a homology sound-based algorithm for speech signal interference is proposed in this paper. We first split speech signal into phonetic fragments by a short-term energy method and establish an interference noise cache library with the phonetic fragments. Then we implement the homology sound interference by mixing the randomly selected interferential fragments and the original speech in real time. The computer simulation results indicated that the interference produced by this algorithm has advantages of real time, randomness, and high correlation with the original signal, comparing with the traditional noise interference methods such as white noise interference. After further studies, the proposed algorithm may be readily used in secure speech communication.

  2. The endless tale of non-homologous end-joining.

    Science.gov (United States)

    Weterings, Eric; Chen, David J

    2008-01-01

    DNA double-strand breaks (DSBs) are introduced in cells by ionizing radiation and reactive oxygen species. In addition, they are commonly generated during V(D)J recombination, an essential aspect of the developing immune system. Failure to effectively repair these DSBs can result in chromosome breakage, cell death, onset of cancer, and defects in the immune system of higher vertebrates. Fortunately, all mammalian cells possess two enzymatic pathways that mediate the repair of DSBs: homologous recombination and non-homologous end-joining (NHEJ). The NHEJ process utilizes enzymes that capture both ends of the broken DNA molecule, bring them together in a synaptic DNA-protein complex, and finally repair the DNA break. In this review, all the known enzymes that play a role in the NHEJ process are discussed and a working model for the co-operation of these enzymes during DSB repair is presented.

  3. Homology and isomorphism: Bourdieu in conversation with New Institutionalism.

    Science.gov (United States)

    Wang, Yingyao

    2016-06-01

    Bourdieusian Field Theory (BFT) provided decisive inspiration for the early conceptual formulation of New Institutionalism (NI). This paper attempts to reinvigorate the stalled intellectual dialogue between NI and BFT by comparing NI's concept of isomorphism with BFT's notion of homology. I argue that Bourdieu's understanding of domination-oriented social action, transposable habitus, and a non-linear causality, embodied in his neglected concept of homology, provides an alternative theorization of field-level convergence to New Institutionalism's central idea of institutional isomorphism. To showcase how BFT can be useful for organizational research, I postulate a habitus-informed and field-conditioned theory of transference to enrich NI's spin-off thesis of 'diffusion'. I propose that while NI can benefit from BFT's potential of bringing social structure back into organizational research, BFT can enrich its social analysis by borrowing from NI's elaboration of the symbolic system of organizations. © London School of Economics and Political Science 2016.

  4. RTEL1 maintains genomic stability by suppressing homologous recombination.

    Science.gov (United States)

    Barber, Louise J; Youds, Jillian L; Ward, Jordan D; McIlwraith, Michael J; O'Neil, Nigel J; Petalcorin, Mark I R; Martin, Julie S; Collis, Spencer J; Cantor, Sharon B; Auclair, Melissa; Tissenbaum, Heidi; West, Stephen C; Rose, Ann M; Boulton, Simon J

    2008-10-17

    Homologous recombination (HR) is an important conserved process for DNA repair and ensures maintenance of genome integrity. Inappropriate HR causes gross chromosomal rearrangements and tumorigenesis in mammals. In yeast, the Srs2 helicase eliminates inappropriate recombination events, but the functional equivalent of Srs2 in higher eukaryotes has been elusive. Here, we identify C. elegans RTEL-1 as a functional analog of Srs2 and describe its vertebrate counterpart, RTEL1, which is required for genome stability and tumor avoidance. We find that rtel-1 mutant worms and RTEL1-depleted human cells share characteristic phenotypes with yeast srs2 mutants: lethality upon deletion of the sgs1/BLM homolog, hyperrecombination, and DNA damage sensitivity. In vitro, purified human RTEL1 antagonizes HR by promoting the disassembly of D loop recombination intermediates in a reaction dependent upon ATP hydrolysis. We propose that loss of HR control after deregulation of RTEL1 may be a critical event that drives genome instability and cancer.

  5. FastBLAST: homology relationships for millions of proteins.

    Directory of Open Access Journals (Sweden)

    Morgan N Price

    Full Text Available BACKGROUND: All-versus-all BLAST, which searches for homologous pairs of sequences in a database of proteins, is used to identify potential orthologs, to find new protein families, and to provide rapid access to these homology relationships. As DNA sequencing accelerates and data sets grow, all-versus-all BLAST has become computationally demanding. METHODOLOGY/PRINCIPAL FINDINGS: We present FastBLAST, a heuristic replacement for all-versus-all BLAST that relies on alignments of proteins to known families, obtained from tools such as PSI-BLAST and HMMer. FastBLAST avoids most of the work of all-versus-all BLAST by taking advantage of these alignments and by clustering similar sequences. FastBLAST runs in two stages: the first stage identifies additional families and aligns them, and the second stage quickly identifies the homologs of a query sequence, based on the alignments of the families, before generating pairwise alignments. On 6.53 million proteins from the non-redundant Genbank database ("NR", FastBLAST identifies new families 25 times faster than all-versus-all BLAST. Once the first stage is completed, FastBLAST identifies homologs for the average query in less than 5 seconds (8.6 times faster than BLAST and gives nearly identical results. For hits above 70 bits, FastBLAST identifies 98% of the top 3,250 hits per query. CONCLUSIONS/SIGNIFICANCE: FastBLAST enables research groups that do not have supercomputers to analyze large protein sequence data sets. FastBLAST is open source software and is available at http://microbesonline.org/fastblast.

  6. How do exhibition visitors describe aesthetic qualities?

    DEFF Research Database (Denmark)

    Thomsen, Bente Dahl; Ravn, Anders Peter

    2007-01-01

    In this investigation, visitors to an art and design exhibition have used an interactive computer program to express the qualities they consider important for an art or design object (artefact). They have then used the program with their individually selected qualities to assess the artefacts. In...

  7. CERN exhibition wins yet another design prize

    CERN Multimedia

    Joannah Caborn Wengler

    2012-01-01

    The “Universe of Particles” exhibition in CERN’s Globe wins the silver design prize from the German direct business communications association FAMAB.   Not only do tens of thousands of people visit the “Universe of Particles” exhibition each year, but juries for design prizes are crossing its threshold more and more frequently too. In 2011 alone it claimed 8 awards, including winning outright the 2011 Annual Multimedia award, the iF Communication Design for Corporate Architecture award and the Modern Decoration Media award (the Bulletin already reported on some of these in July 2011). The FAMAB award is the latest to join the prestigious list. The jury of FAMAB’s “ADAM 2011” award was particularly impressed by the hands-on nature of the exhibition, which encourages visitors to get interested in science. They also appreciated the way that the space in the Globe is not just a container for the exhibits, but itself ...

  8. 49 CFR 250.2 - Required exhibits.

    Science.gov (United States)

    2010-10-01

    ... carried; and identification of the ten most important industries served. (6) As Exhibit 6, statement as to... application for the financing has been made, evidencing that they have declined the financing unless guaranteed by the Secretary or specifying the terms upon which they will undertake the financing without such...

  9. CCPIT Machinery Exhibition Succeeded in Kuala Lumpur

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ From August 18 to 20, 2005, China Council for the Promotion of International Trade(CCPIT) held China Machinery and Electronics Trade Exhibition, CME 2005 in Kuala Lumpur, the capital of Malaysia on behalf of China, a good job has been done.

  10. CCPIT Machinery Exhibition Succeeded in Kuala Lumpur

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

      From August 18 to 20, 2005, China Council for the Promotion of International Trade(CCPIT) held China Machinery and Electronics Trade Exhibition, CME 2005 in Kuala Lumpur, the capital of Malaysia on behalf of China, a good job has been done.……

  11. Comic Strips to Accompany Science Museum Exhibits

    Science.gov (United States)

    Chung, Beom Sun; Park, Eun-mi; Kim, Sang-Hee; Cho, Sook-kyoung; Chung, Min Suk

    2016-01-01

    Science museums make the effort to create exhibits with amusing explanations. However, existing explanation signs with lengthy text are not appealing, and as such, visitors do not pay attention to them. In contrast, conspicuous comic strips composed of simple drawings and humors can attract science museum visitors. This study attempted to reveal…

  12. 18 CFR 50.7 - Applications: exhibits.

    Science.gov (United States)

    2010-04-01

    ... systems, including the special protective systems' automatic switching or load shedding system; and (ii... transfer capability (NITC); system protection; and system stability. (3) A stability analysis including... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Applications: exhibits...

  13. Homologous Recombination in Protozoan Parasites and Recombinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Andrew A. Kelso

    2017-09-01

    Full Text Available Homologous recombination (HR is a DNA double-strand break (DSB repair pathway that utilizes a homologous template to fully repair the damaged DNA. HR is critical to maintain genome stability and to ensure genetic diversity during meiosis. A specialized class of enzymes known as recombinases facilitate the exchange of genetic information between sister chromatids or homologous chromosomes with the help of numerous protein accessory factors. The majority of the HR machinery is highly conserved among eukaryotes. In many protozoan parasites, HR is an essential DSB repair pathway that allows these organisms to adapt to environmental conditions and evade host immune systems through genetic recombination. Therefore, small molecule inhibitors, capable of disrupting HR in protozoan parasites, represent potential therapeutic options. A number of small molecule inhibitors were identified that disrupt the activities of the human recombinase RAD51. Recent studies have examined the effect of two of these molecules on the Entamoeba recombinases. Here, we discuss the current understandings of HR in the protozoan parasites Trypanosoma, Leishmania, Plasmodium, and Entamoeba, and we review the small molecule inhibitors known to disrupt human RAD51 activity.

  14. Phenylbutyrate inhibits homologous recombination induced by camptothecin and methyl methanesulfonate.

    Science.gov (United States)

    Kaiser, Gitte S; Germann, Susanne M; Westergaard, Tine; Lisby, Michael

    2011-08-01

    Homologous recombination is accompanied by extensive changes to chromatin organization at the site of DNA damage. Some of these changes are mediated through acetylation/deacetylation of histones. Here, we show that recombinational repair of DNA damage induced by the anti-cancer drug camptothecin (CPT) and the alkylating agent methyl methanesulfonate (MMS) is blocked by sodium phenylbutyrate (PBA) in the budding yeast Saccharomyces cerevisiae. In particular, PBA suppresses CPT- and MMS-induced genetic recombination as well as DNA double-strand break repair during mating-type interconversion. Treatment with PBA is accompanied by a dramatic reduction in histone H4 lysine 8 acetylation. Live cell imaging of homologous recombination proteins indicates that repair of CPT-induced DNA damage is redirected to a non-recombinogenic pathway in the presence of PBA without loss in cell viability. In contrast, the suppression of MMS-induced recombination by PBA is accompanied by a dramatic loss in cell viability. Taken together, our results demonstrate that PBA inhibits DNA damage-induced homologous recombination likely by mediating changes in chromatin acetylation. Moreover, the combination of PBA with genotoxic agents can lead to different cell fates depending on the type of DNA damage inflicted. 2011 Elsevier B.V. All rights reserved.

  15. Membrane and Protein Interactions of the Pleckstrin Homology Domain Superfamily

    Directory of Open Access Journals (Sweden)

    Marc Lenoir

    2015-10-01

    Full Text Available The human genome encodes about 285 proteins that contain at least one annotated pleckstrin homology (PH domain. As the first phosphoinositide binding module domain to be discovered, the PH domain recruits diverse protein architectures to cellular membranes. PH domains constitute one of the largest protein superfamilies, and have diverged to regulate many different signaling proteins and modules such as Dbl homology (DH and Tec homology (TH domains. The ligands of approximately 70 PH domains have been validated by binding assays and complexed structures, allowing meaningful extrapolation across the entire superfamily. Here the Membrane Optimal Docking Area (MODA program is used at a genome-wide level to identify all membrane docking PH structures and map their lipid-binding determinants. In addition to the linear sequence motifs which are employed for phosphoinositide recognition, the three dimensional structural features that allow peripheral membrane domains to approach and insert into the bilayer are pinpointed and can be predicted ab initio. The analysis shows that conserved structural surfaces distinguish which PH domains associate with membrane from those that do not. Moreover, the results indicate that lipid-binding PH domains can be classified into different functional subgroups based on the type of membrane insertion elements they project towards the bilayer.

  16. Prefiltering Model for Homology Detection Algorithms on GPU.

    Science.gov (United States)

    Retamosa, Germán; de Pedro, Luis; González, Ivan; Tamames, Javier

    2016-01-01

    Homology detection has evolved over the time from heavy algorithms based on dynamic programming approaches to lightweight alternatives based on different heuristic models. However, the main problem with these algorithms is that they use complex statistical models, which makes it difficult to achieve a relevant speedup and find exact matches with the original results. Thus, their acceleration is essential. The aim of this article was to prefilter a sequence database. To make this work, we have implemented a groundbreaking heuristic model based on NVIDIA's graphics processing units (GPUs) and multicore processors. Depending on the sensitivity settings, this makes it possible to quickly reduce the sequence database by factors between 50% and 95%, while rejecting no significant sequences. Furthermore, this prefiltering application can be used together with multiple homology detection algorithms as a part of a next-generation sequencing system. Extensive performance and accuracy tests have been carried out in the Spanish National Centre for Biotechnology (NCB). The results show that GPU hardware can accelerate the execution times of former homology detection applications, such as National Centre for Biotechnology Information (NCBI), Basic Local Alignment Search Tool for Proteins (BLASTP), up to a factor of 4.

  17. Membrane and Protein Interactions of the Pleckstrin Homology Domain Superfamily.

    Science.gov (United States)

    Lenoir, Marc; Kufareva, Irina; Abagyan, Ruben; Overduin, Michael

    2015-10-23

    The human genome encodes about 285 proteins that contain at least one annotated pleckstrin homology (PH) domain. As the first phosphoinositide binding module domain to be discovered, the PH domain recruits diverse protein architectures to cellular membranes. PH domains constitute one of the largest protein superfamilies, and have diverged to regulate many different signaling proteins and modules such as Dbl homology (DH) and Tec homology (TH) domains. The ligands of approximately 70 PH domains have been validated by binding assays and complexed structures, allowing meaningful extrapolation across the entire superfamily. Here the Membrane Optimal Docking Area (MODA) program is used at a genome-wide level to identify all membrane docking PH structures and map their lipid-binding determinants. In addition to the linear sequence motifs which are employed for phosphoinositide recognition, the three dimensional structural features that allow peripheral membrane domains to approach and insert into the bilayer are pinpointed and can be predicted ab initio. The analysis shows that conserved structural surfaces distinguish which PH domains associate with membrane from those that do not. Moreover, the results indicate that lipid-binding PH domains can be classified into different functional subgroups based on the type of membrane insertion elements they project towards the bilayer.

  18. Microarrays for global expression constructed with a low redundancy set of 27,500 sequenced cDNAs representing an array of developmental stages and physiological conditions of the soybean plant

    Directory of Open Access Journals (Sweden)

    Retzel Ernest

    2004-09-01

    Full Text Available Abstract Background Microarrays are an important tool with which to examine coordinated gene expression. Soybean (Glycine max is one of the most economically valuable crop species in the world food supply. In order to accelerate both gene discovery as well as hypothesis-driven research in soybean, global expression resources needed to be developed. The applications of microarray for determining patterns of expression in different tissues or during conditional treatments by dual labeling of the mRNAs are unlimited. In addition, discovery of the molecular basis of traits through examination of naturally occurring variation in hundreds of mutant lines could be enhanced by the construction and use of soybean cDNA microarrays. Results We report the construction and analysis of a low redundancy 'unigene' set of 27,513 clones that represent a variety of soybean cDNA libraries made from a wide array of source tissue and organ systems, developmental stages, and stress or pathogen-challenged plants. The set was assembled from the 5' sequence data of the cDNA clones using cluster analysis programs. The selected clones were then physically reracked and sequenced at the 3' end. In order to increase gene discovery from immature cotyledon libraries that contain abundant mRNAs representing storage protein gene families, we utilized a high density filter normalization approach to preferentially select more weakly expressed cDNAs. All 27,513 cDNA inserts were amplified by polymerase chain reaction. The amplified products, along with some repetitively spotted control or 'choice' clones, were used to produce three 9,728-element microarrays that have been used to examine tissue specific gene expression and global expression in mutant isolines. Conclusions Global expression studies will be greatly aided by the availability of the sequence-validated and low redundancy cDNA sets described in this report. These cDNAs and ESTs represent a wide array of developmental

  19. Membrane-Tethered Delta-Like 1 Homolog (DLK1) Restricts Adipose Tissue Size By Inhibiting Preadipocyte Proliferation

    DEFF Research Database (Denmark)

    Mortensen, Sussi B; Jensen, Charlotte H; Schneider, Mikael

    2012-01-01

    Adipocyte renewal from preadipocytes has been shown to occur throughout life and to contribute to obesity, yet very little is known about the molecular circuits that control preadipocyte expansion. The soluble form of the preadipocyte factor (also known as pref-1) delta-like 1 homolog (DLK1(S...... in vivo. Here, we demonstrate for the first time that only membrane-bound DLK1 (DLK1(M)) exhibits a substantial repression effect on preadipocyte proliferation. Thus, by independently manipulating DLK1 isoform levels, we established that DLK1(M) inhibits G1-to-S-phase cell cycle progression and thereby...

  20. The Arabidopsis thaliana Homolog of the Helicase RTEL1 Plays Multiple Roles in Preserving Genome Stability[C][W

    Science.gov (United States)

    Recker, Julia; Knoll, Alexander; Puchta, Holger

    2014-01-01

    In humans, mutations in the DNA helicase Regulator of Telomere Elongation Helicase1 (RTEL1) lead to Hoyeraal-Hreidarsson syndrome, a severe, multisystem disorder. Here, we demonstrate that the RTEL1 homolog in Arabidopsis thaliana plays multiple roles in preserving genome stability. RTEL1 suppresses homologous recombination in a pathway parallel to that of the DNA translocase FANCM. Cytological analyses of root meristems indicate that RTEL1 is involved in processing DNA replication intermediates independently from FANCM and the nuclease MUS81. Moreover, RTEL1 is involved in interstrand and intrastrand DNA cross-link repair independently from FANCM and (in intrastrand cross-link repair) parallel to MUS81. RTEL1 contributes to telomere homeostasis; the concurrent loss of RTEL1 and the telomerase TERT leads to rapid, severe telomere shortening, which occurs much more rapidly than it does in the single-mutant line tert, resulting in developmental arrest after four generations. The double mutant rtel1-1 recq4A-4 exhibits massive growth defects, indicating that this RecQ family helicase, which is also involved in the suppression of homologous recombination and the repair of DNA lesions, can partially replace RTEL1 in the processing of DNA intermediates. The requirement for RTEL1 in multiple pathways to preserve genome stability in plants can be explained by its putative role in the destabilization of DNA loop structures, such as D-loops and T-loops. PMID:25516598

  1. Travelling CERN Exhibition ''When Energy Becomes Matter''

    International Nuclear Information System (INIS)

    2001-01-01

    Full text: The European Laboratory for Nuclear Research (CERN) and the H. Niewodniczanski Institute of Nuclear Physics together with the Institute of Physics of the Jagiellonian University and the University of Mining and Metallurgy, and under the auspices of the Polish National Atomic Energy Agency organized in the Museum of Nature in Cracow from October 16 till December 16, 2000 the exhibition ''When Energy Becomes Matter''. The Office of the ''Festival Cracow 2000'' was the main sponsor of that event. The exhibition was a part of the F estival Cracow 2000'' called ''Festival of Youngsters Cracow 2000''. Invitations, posters and information leaflets were sent to more than 3000 schools in southern Poland. The exhibition was divided into four specially designed quadrants. In the first the visitor was informed what kind of scales are in use to describe the Universe and the atom. The second introduced elementary particles via the cosmic ray demonstrations. Particle acceleration was demonstrated with the help of a TV set. The third segment was devoted to the Large Hadron Collider and its experiments: CMS, ATLAS, ALICE and LHCb. The last segment was an attempt to explain what are quarks, leptons and intermediate bosons. In addition it was also explained what is antimatter and why symmetry is broken in Nature. In one of the rooms we arranged the cinema where five movies was continuously presented. Thanks to the Cracow TV it was possible to prepare Polish translations of the films: B ack to creation , P owers of ten , L HC - time machine , S tars underground , and G eneva event . Another attraction of the exhibition was the Internet room equipped with the help of Polish Telecommunication. The exhibition was open seven days per week from 10 to 17 h. During the working days every 20 minutes a new group of about 25-30 people was visiting the exhibition. Each group was guided by students and PhD students from our Institute, Jagiellonian University and University of Mining

  2. Genetic selection and DNA sequences of 4.5S RNA homologs

    DEFF Research Database (Denmark)

    Brown, S; Thon, G; Tolentino, E

    1989-01-01

    A general strategy for cloning the functional homologs of an Escherichia coli gene was used to clone homologs of 4.5S RNA from other bacteria. The genes encoding these homologs were selected by their ability to complement a deletion of the gene for 4.5S RNA. DNA sequences of the regions encoding...

  3. Study on homologous series of induced early mutants in Indica rice Ⅱ. the relationship between the homologous series of early mutants induced and the ecotype in Indica rice

    International Nuclear Information System (INIS)

    Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

    2001-01-01

    The induced mutation in light sensitivity of the Indica rice leads to induction of the homologous series of early mutants along with the variation of ecological character and the ecoclimate. The induction of mutants was closely related to the ecotype of Indica rice, the homologous series of early mutants in different level were derived from the different ecotype of the Indica rice, otherwise, the similar homologous series of early mutants were derived from the same ecotypic variety. The induction of the early ecotypic variety derived from the homologous series of early mutants provides the basis and possibility for accelerating the development of the new cultivars. (authors)

  4. LHC INAUGURATION, LHC Fest highlights: exhibition time!

    CERN Multimedia

    2008-01-01

    David Gross, one of the twenty-one Nobel Laureates who have participated in the project.Tuesday 21 October 2008 Accelerating Nobels Colliding Charm, Atomic Cuisine, The Good Anomaly, A Quark Somewhere on the White Paper, Wire Proliferation, A Tale of Two Liquids … these are just some of the titles given to artworks by Physics Nobel Laureates who agreed to make drawings of their prize-winning discoveries (more or less reluctantly) during a special photo session. Science photographer Volker Steger made portraits of Physics Nobel Laureates and before the photo sessions he asked them to make a drawing of their most important discovery. The result is "Accelerating Nobels", an exhibition that combines unusual portraits of and original drawings by twenty-one Nobel laureates in physics whose work is closely related to CERN and the LHC. This exhibition will be one of the highlights of the LHC celebrations on 21 October in the SM18 hall b...

  5. Exhibition: Women and Sciences by Fiami

    CERN Multimedia

    Globe Info

    2011-01-01

    The 19-panel exhibition is on display at CERN's Microcosm from Monday to Saturday from 10.00 a.m. to 5.00 p.m.   Marie Curie won the Nobel Prize for Chemistry one hundred years ago. She is the only woman ever to win two Nobel Prizes, which is a testament to her remarkable work. But throughout history, women have played a role in science either in their own right or alongside other scientists. In this special exhibition, the comic-strip artist Fiami takes a look back at the relationship between women and science through his portraits of Mileva Einstein, Marie-Anne Lavoisier and, of course, Marie Curie. Fiami has recently published an entire album devoted to Marie Curie. Texts in French All ages - Entrance free Femmes et Sciences is on display at Microcosm: From Wednesday 21 September 2011 to Tuesday 20 December 2011.

  6. Kuala Namu Convention And Exhibition Centre

    OpenAIRE

    Gustriana, Trisna

    2017-01-01

    Aerotropolis area development that is expected to accommodate the development of business and commercial appeal and this is the chance for the designer to be able to take advantage of the situation and condition of land as well as possible. So that the revolutionary changes but is able to embrace all stakeholders is the solution needed to development Aerotropolis. Kuala Namu's Convention and Exhibition Center is expected to be a solution for regional development of Kuala Namu a...

  7. 22nd Annual Logistics Conference and Exhibition

    Science.gov (United States)

    2006-04-20

    Bill” Kenwell, Vice President, Sales and Marketing, Maersk 5:30pm-7:30pm Reception in Exhibit Hall Wednesday, April 19, 2006 7:00am-5:30pm...some commercial sales of our products, services and platforms. We provide surface, air, and undersea applications on more than 460 programs for US...diagnostic system & process • Seamless B2B integration with maintenance systems Enabled By… EOATM Overview Sensor Data Maintenance Logs Repair Data Expert

  8. The Factory of the Future, Group Exhibition

    OpenAIRE

    Dean, Lionel T.

    2016-01-01

    3D Printing, The factory of the future, Lieu du Design (centre for Design), Paris This exhibition dedicated entirely to 3D printing technology was billed as “the first in France wholly devoted to exploring the interdisciplinary and multifaceted topic of 3D printing technology and its undeniable influence on everything from industry, to economics, to creative and social issues, demonstrated to the public through achievements in the fields of 3D design, 3D printed architecture, 3D printed fa...

  9. Brazilian air traffic controllers exhibit excessive sleepiness.

    Science.gov (United States)

    Ribas, Valdenilson Ribeiro; de Almeida, Cláudia Ângela Vilela; Martins, Hugo André de Lima; Alves, Carlos Frederico de Oliveira; Alves, Marcos José Pinheiro Cândido; Carneiro, Severino Marcos de Oliveira; Ribas, Valéria Ribeiro; de Vasconcelos, Carlos Augusto Carvalho; Sougey, Everton Botelho; de Castro, Raul Manhães

    2011-01-01

    Excessive sleepiness (ES) is an increased tendency to initiate involuntary sleep for naps at inappropriate times. The objective of this study was to assess ES in air traffic controllers (ATCo). 45 flight protection professionals were evaluated, comprising 30 ATCo, subdivided into ATCo with ten or more years in the profession (ATCo≥10, n=15) and ATCo with less than ten years in the profession (ATCoair traffic controllers exhibit excessive sleepiness.

  10. Naval Meteorology and Oceanography Command exhibit entrance

    Science.gov (United States)

    2000-01-01

    StenniSphere at NASA's John C. Stennis Space Center in Hancock County, Miss., invites visitors to discover why America comes to Stennis Space Center before going into space. Designed to entertain while educating, StenniSphere includes informative displays and exhibits from NASA and other agencies located at Stennis, such as this one from the Naval Meteorology and Oceanography Command. Visitors can 'travel' three-dimensionally under the sea and check on the weather back home in the Weather Center.

  11. Naval Meteorology and Oceanography Command exhibit

    Science.gov (United States)

    2000-01-01

    Designed to entertain while educating, StenniSphere at the John C. Stennis Space Center in Hancock County, Miss., includes informative displays and exhibits from NASA and other agencies located at Stennis, such as this one from the Naval Meteorology and Oceanography Command. Visitors can 'travel' three-dimensionally under the sea and check on the weather back home in the Weather Center. StenniSphere is open free of charge from 9 a.m. to 5 p.m. daily.

  12. Exhibition: Linus Pauling and the Twentieth Century

    CERN Document Server

    2003-01-01

    On April 28 the exhibit Linus Pauling and the Twentieth Century organised by UNIDIR (United Nations Institute for Disarmament Research) and SGI (Soka Gakkai International) as well as with the contributions of CERN and the University of Geneva, opened at the United Nations Office of Geneva. Linus Pauling is the only person to date to have won two unshared Nobel Prizes: Chemistry in 1954 and Peace in 1962. The first was awarded for his landmark research on the nature of the chemical bond and its application in understanding the structure of complex substances. The second one acknowledged his courageous protest against atmospheric nuclear testing and his championship of international peace. The exhibit, for audience of all ages, traces seven decades of Linus Pauling's life and influence on the 20th century. Before starting its European tour at the UNESCO headquarters in Paris, the exhibit opened in 1998 in San Francisco and then travelled within the United-States and to Japan with an attendance of more than one...

  13. Exhibition: Linus Pauling and the Twentieth Century

    CERN Document Server

    2003-01-01

    On April 28 the exhibit Linus Pauling and the Twentieth Century organised by UNIDIR (United Nations Institute for Disarmament Research) and SGI (Soka Gakkai International) as well as with the contributions of CERN and the University of Geneva, opens at the United Nations Office of Geneva. Linus Pauling is the only person to date to have won two unshared Nobel Prizes: Chemistry in 1954 and Peace in 1962. The first was awarded for his landmark research on the nature of the chemical bond and its application in understanding the structure of complex substances. The second one acknowledged his courageous protest against atmospheric nuclear testing and his championship of international peace. The exhibit, for all ages' audiences, traces seven decades of Linus Pauling's life and influence on the 20th century. Before starting its European tour at the UNESCO headquarters in Paris, the exhibit opened in 1998 in San Francisco and then travelled within the United-States and to Japan with an attendance of more than one m...

  14. Bumblebees exhibit the memory spacing effect

    Science.gov (United States)

    Toda, Nicholas R. T.; Song, Jeremy; Nieh, James C.

    2009-10-01

    Associative learning is key to how bees recognize and return to rewarding floral resources. It thus plays a major role in pollinator floral constancy and plant gene flow. Honeybees are the primary model for pollinator associative learning, but bumblebees play an important ecological role in a wider range of habitats, and their associative learning abilities are less well understood. We assayed learning with the proboscis extension reflex (PER), using a novel method for restraining bees (capsules) designed to improve bumblebee learning. We present the first results demonstrating that bumblebees exhibit the memory spacing effect. They improve their associative learning of odor and nectar reward by exhibiting increased memory acquisition, a component of long-term memory formation, when the time interval between rewarding trials is increased. Bombus impatiens forager memory acquisition (average discrimination index values) improved by 129% and 65% at inter-trial intervals (ITI) of 5 and 3 min, respectively, as compared to an ITI of 1 min. Memory acquisition rate also increased with increasing ITI. Encapsulation significantly increases olfactory memory acquisition. Ten times more foragers exhibited at least one PER response during training in capsules as compared to traditional PER harnesses. Thus, a novel conditioning assay, encapsulation, enabled us to improve bumblebee-learning acquisition and demonstrate that spaced learning results in better memory consolidation. Such spaced learning likely plays a role in forming long-term memories of rewarding floral resources.

  15. Exhibition: Dialogue between Science and religion

    CERN Multimedia

    2001-01-01

    Can the theory of the Big Bang reached by physicists and the concept of creation beloved of religion ever be reconciled? The two approaches have at least one point in common: they do not provide a final answer to the mysteries of the birth of the Universe. And this means that dialogue is alays possible between the two. It is to show the potential of such an exchange that Geneva's Société Evangélique organization is opening an exhibition under the title 'Big Bang and Creation', at the Planète Charmilles shopping centre, to run from 19 to 30 March. View of the 'Big Bang and Creation' exhibition. The exhibition is divided into three sections, showing the views of the scientist and those of the believer without setting them up in opposition to one another. In the first section, under a representation of the vault of heaven, the visitor will discover the different ideas explaining the birth of the Universe: Genesis and the Big Bang, and the different dominant theories ...

  16. Art exhibit focuses on African astronomy

    Science.gov (United States)

    Showstack, Randy

    2012-07-01

    Connections between Africans and astronomy are the focus of a new exhibition in the National Museum of African Art in Washington, D. C. "African Cosmos: Stellar Arts," which includes artwork, cultural items, and scientific displays from ancient to contemporary times, is the first major exhibit "that brings together arts and science focused on Africa's contribution to keen observations of the heavens over time," curator Christine Mullen Kreamer said at a 20 June news briefing. Among the exhibit's nearly 100 objects are an ancient Egyptian mummy board that includes a representation of the sky goddess Nut, sculptures by the Dogon people of Mali depicting figures in relation to the cosmos, a video that uses data from two square degrees of the Hubble Space Telescope Cosmic Evolution Survey, and a nearly floor-to-ceiling "Rainbow Serpent" constructed of plastic containers by Benin artist Hazoume. An untitled acrylic painting (Figure 1) by South African Gavin Jantjes evokes a myth of the Khoi San people of southern Africa, as it portrays a girl throwing evening fire embers into the night sky, where they remained as the Milky Way.

  17. Isolation of Nicotiana plumbaginifolia cDNAs encoding isoforms of serine acetyltransferase and O-acetylserine (thiol) lyase in a yeast two-hybrid system with Escherichia coli cysE and cysK genes as baits.

    Science.gov (United States)

    Liszewska, Frantz; Gaganidze, Dali; Sirko, Agnieszka

    2005-01-01

    We applied the yeast two-hybrid system for screening of a cDNA library of Nicotiana plumbaginifolia for clones encoding plant proteins interacting with two proteins of Escherichia coli: serine acetyltransferase (SAT, the product of cysE gene) and O-acetylserine (thiol)lyase A, also termed cysteine synthase (OASTL-A, the product of cysK gene). Two plant cDNA clones were identified when using the cysE gene as a bait. These clones encode a probable cytosolic isoform of OASTL and an organellar isoform of SAT, respectively, as indicated by evolutionary trees. The second clone, encoding SAT, was identified independently also as a "prey" when using cysK as a bait. Our results reveal the possibility of applying the two-hybrid system for cloning of plant cDNAs encoding enzymes of the cysteine synthase complex in the two-hybrid system. Additionally, using genome walking sequences located upstream of the sat1 cDNA were identified. Subsequently, in silico analyses were performed aiming towards identification of the potential signal peptide and possible location of the deduced mature protein encoded by sat1.

  18. p53 regulates the repair of DNA double-strand breaks by both homologous and non-homologous recombination

    International Nuclear Information System (INIS)

    Willers, H.; Powell, S.N.; Dahm-Daphi, J.

    2003-01-01

    Full text: p53 is known to suppress spontaneous homologous recombination (HR), while its role in non-homologous recombination (NHR) remains to be clarified. Here, we sought to determine the influence of p53 on the repair of chromosomal double-strand breaks (DSBs) by HR or NHR using specially designed recombination substrates that integrate into the genome. Isogenic mouse fibroblast pairs with or without expression of exogenous p53 protein were utilized. A reporter plasmid carrying a mutated XGPRT gene was chromosomally integrated and DSBs were generated within the plasmid by the I-SceI endonuclease. Subsequent homology-mediated repair from an episomal donor resulted in XGPRT reconstitution and cellular resistance to a selection antibiotic. Analogously, the repair of chromosomal I-SceI breaks by NHR using another novel reporter plasmid restored XGPRT translation. For p53-null cells, the mean frequency of I-SceI break repair via HR was 5.5 x 10 -4 . The p53-Val135 mutant, which previously has been shown to suppress spontaneous HR by 14-fold employing the same cell system and reporter gene, only caused a 2- to 3-fold suppression of break-induced HR. In contrast, a dramatic effect of p53 on repair via NHR was found. Preliminary sequence analysis indicated that there was at least a 1000-fold reduction of illegitimate repair events resulting in loss of sequence at the break sites. The observed effects were mediated by p53 mutants defective in regulation of the cell-cycle and apoptosis. The main findings were: (1) p53 virtually blocked illegitimate rejoining of chromosomal ends. (2) The suppression of homologous DSB repair was less pronounced than the inhibition of spontaneous HR. We hypothesize that p53 allows to a certain extent error-free homology-dependent repair to proceed, while blocking error-prone NHR. The data support and extent a previous model, in which p53 maintains genomic stability by regulating recombination independently of its transactivation function

  19. Homologous mechanisms of visuospatial working memory maintenance in macaque and human: Properties and sources

    Science.gov (United States)

    Reinhart, Robert M.G.; Heitz, Richard P.; Purcell, Braden A.; Weigand, Pauline K.; Schall, Jeffrey D.; Woodman, Geoffrey F.

    2012-01-01

    Although areas of frontal cortex are thought to be critical for maintaining information in visuospatial working memory, the event-related potential (ERP) index of maintenance is found over posterior cortex in humans. In the present study, we reconcile these seemingly contradictory findings. Here we show that macaque monkeys and humans exhibit the same posterior ERP signature of working memory maintenance that predicts the precision of the memory-based behavioral responses. In addition, we show that the specific pattern of rhythmic oscillations in the alpha band, recently demonstrated to underlie the human visual working memory ERP component, is also present in monkeys. Next, we concurrently recorded intracranial local field potentials from two prefrontal and another frontal cortical area to determine their contribution to the surface potential indexing maintenance. The local fields in the two prefrontal areas, but not the cortex immediately posterior, exhibited amplitude modulations, timing, and relationships to behavior indicating that they contribute to the generation of the surface ERP component measured from the distal posterior electrodes. Rhythmic neural activity in the theta and gamma bands during maintenance provided converging support for the engagement of the same brain regions. These findings demonstrate that nonhuman primates have homologous electrophysiological signatures of visuospatial working memory to those of humans and that a distributed neural network, including frontal areas, underlies the posterior ERP index of visuospatial working memory maintenance. PMID:22649249

  20. Structural insights into the anti-HIV activity of the Oscillatoria agardhii agglutinin homolog lectin family.

    Science.gov (United States)

    Koharudin, Leonardus M I; Kollipara, Sireesha; Aiken, Christopher; Gronenborn, Angela M

    2012-09-28

    Oscillatoria agardhii agglutinin homolog (OAAH) proteins belong to a recently discovered lectin family. All members contain a sequence repeat of ~66 amino acids, with the number of repeats varying among different family members. Apart from data for the founding member OAA, neither three-dimensional structures, information about carbohydrate binding specificities, nor antiviral activity data have been available up to now for any other members of the OAAH family. To elucidate the structural basis for the antiviral mechanism of OAAHs, we determined the crystal structures of Pseudomonas fluorescens and Myxococcus xanthus lectins. Both proteins exhibit the same fold, resembling the founding family member, OAA, with minor differences in loop conformations. Carbohydrate binding studies by NMR and x-ray structures of glycan-lectin complexes reveal that the number of sugar binding sites corresponds to the number of sequence repeats in each protein. As for OAA, tight and specific binding to α3,α6-mannopentaose was observed. All the OAAH proteins described here exhibit potent anti-HIV activity at comparable levels. Altogether, our results provide structural details of the protein-carbohydrate interaction for this novel lectin family and insights into the molecular basis of their HIV inactivation properties.

  1. Library exhibits and programs boost science education

    Science.gov (United States)

    Dusenbery, Paul B.; Curtis, Lisa

    2012-05-01

    Science museums let visitors explore and discover, but for many families there are barriers—such as cost or distance—that prevent them from visiting museums and experiencing hands-on science, technology, engineering, and mathematics (STEM) learning. Now educators are reaching underserved audiences by developing STEM exhibits and programs for public libraries. With more than 16,000 outlets in the United States, public libraries serve almost every community in the country. Nationwide, they receive about 1.5 billion visits per year, and they offer their services for free.

  2. The colocalization transition of homologous chromosomes at meiosis

    Science.gov (United States)

    Nicodemi, Mario; Panning, Barbara; Prisco, Antonella

    2008-06-01

    Meiosis is the specialized cell division required in sexual reproduction. During its early stages, in the mother cell nucleus, homologous chromosomes recognize each other and colocalize in a crucial step that remains one of the most mysterious of meiosis. Starting from recent discoveries on the system molecular components and interactions, we discuss a statistical mechanics model of chromosome early pairing. Binding molecules mediate long-distance interaction of special DNA recognition sequences and, if their concentration exceeds a critical threshold, they induce a spontaneous colocalization transition of chromosomes, otherwise independently diffusing.

  3. Homology and cohomology of a class of polycyclic groups

    International Nuclear Information System (INIS)

    Majumdar, S.

    1984-11-01

    The homology and the cohomology of the class of polycyclic groups G given by generators h 1 , h 2 ,..., hsub(n+1) and relations h 2 -1 h 1 h 2 =h 1 sup(m 1 ),h 3 -1 h 2 h 3 =h 2 sup(m 2 ),..., hsub(n+1) -1 hsub(n) hsub(n+1)=hsub(n)sup(msub(n)) are determined through the construction of a suitable free ZG resolution for the trivial ZG module Z. (author)

  4. Colour pattern homology and evolution in Vanessa butterflies (Nymphalidae: Nymphalini): eyespot characters.

    Science.gov (United States)

    Abbasi, R; Marcus, J M

    2015-11-01

    Ocelli are serially repeated colour patterns on the wings of many butterflies. Eyespots are elaborate ocelli that function in predator avoidance and deterrence as well as in mate choice. A phylogenetic approach was used to study ocelli and eyespot evolution in Vanessa butterflies, a genus exhibiting diverse phenotypes among these serial homologs. Forty-four morphological characters based on eyespot number, arrangement, shape and the number of elements in each eyespot were defined and scored. Ocelli from eight wing cells on the dorsal and ventral surfaces of the forewing and hindwing were evaluated. The evolution of these characters was traced over a phylogeny of Vanessa based on 7750 DNA base pairs from 10 genes. Our reconstruction predicts that the ancestral Vanessa had 5 serially arranged ocelli on all four wing surfaces. The ancestral state on the dorsal forewing and ventral hindwing was ocelli arranged in two heterogeneous groups. On the dorsal hindwing, the ancestral state was either homogenous or ocelli arranged in two heterogeneous groups. On the ventral forewing, we determined that the ancestral state was organized into three heterogeneous groups. In Vanessa, almost all ocelli are individuated and capable of independent evolution relative to other colour patterns except for the ocelli in cells -1 and 0 on the dorsal and ventral forewings, which appear to be constrained to evolve in parallel. The genus Vanessa is a good model system for the study of serial homology and the interaction of selective forces with developmental architecture to produce diversity in butterfly colour patterns. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  5. Homology-Directed Recombination for Enhanced Engineering of Chimeric Antigen Receptor T Cells

    Directory of Open Access Journals (Sweden)

    Malika Hale

    2017-03-01

    Full Text Available Gene editing by homology-directed recombination (HDR can be used to couple delivery of a therapeutic gene cassette with targeted genomic modifications to generate engineered human T cells with clinically useful profiles. Here, we explore the functionality of therapeutic cassettes delivered by these means and test the flexibility of this approach to clinically relevant alleles. Because CCR5-negative T cells are resistant to HIV-1 infection, CCR5-negative anti-CD19 chimeric antigen receptor (CAR T cells could be used to treat patients with HIV-associated B cell malignancies. We show that targeted delivery of an anti-CD19 CAR cassette to the CCR5 locus using a recombinant AAV homology template and an engineered megaTAL nuclease results in T cells that are functionally equivalent, in both in vitro and in vivo tumor models, to CAR T cells generated by random integration using lentiviral delivery. With the goal of developing off-the-shelf CAR T cell therapies, we next targeted CARs to the T cell receptor alpha constant (TRAC locus by HDR, producing TCR-negative anti-CD19 CAR and anti-B cell maturation antigen (BCMA CAR T cells. These novel cell products exhibited in vitro cytolytic activity against both tumor cell lines and primary cell targets. Our combined results indicate that high-efficiency HDR delivery of therapeutic genes may provide a flexible and robust method that can extend the clinical utility of cell therapeutics.

  6. dyschronic, a Drosophila homolog of a deaf-blindness gene, regulates circadian output and Slowpoke channels.

    Directory of Open Access Journals (Sweden)

    James E C Jepson

    Full Text Available Many aspects of behavior and physiology are under circadian control. In Drosophila, the molecular clock that regulates rhythmic patterns of behavior has been extensively characterized. In contrast, genetic loci involved in linking the clock to alterations in motor activity have remained elusive. In a forward-genetic screen, we uncovered a new component of the circadian output pathway, which we have termed dyschronic (dysc. dysc mutants exhibit arrhythmic locomotor behavior, yet their eclosion rhythms are normal and clock protein cycling remains intact. Intriguingly, dysc is the closest Drosophila homolog of whirlin, a gene linked to type II Usher syndrome, the leading cause of deaf-blindness in humans. Whirlin and other Usher proteins are expressed in the mammalian central nervous system, yet their function in the CNS has not been investigated. We show that DYSC is expressed in major neuronal tracts and regulates expression of the calcium-activated potassium channel SLOWPOKE (SLO, an ion channel also required in the circadian output pathway. SLO and DYSC are co-localized in the brain and control each other's expression post-transcriptionally. Co-immunoprecipitation experiments demonstrate they form a complex, suggesting they regulate each other through protein-protein interaction. Furthermore, electrophysiological recordings of neurons in the adult brain show that SLO-dependent currents are greatly reduced in dysc mutants. Our work identifies a Drosophila homolog of a deaf-blindness gene as a new component of the circadian output pathway and an important regulator of ion channel expression, and suggests novel roles for Usher proteins in the mammalian nervous system.

  7. Cloning and characterization of a functional human homolog of Escherichia coli endonuclease III

    Science.gov (United States)

    Aspinwall, Richard; Rothwell, Dominic G.; Roldan-Arjona, Teresa; Anselmino, Catherine; Ward, Christopher J.; Cheadle, Jeremy P.; Sampson, Julian R.; Lindahl, Tomas; Harris, Peter C.; Hickson, Ian D.

    1997-01-01

    Repair of oxidative damage to DNA bases is essential to prevent mutations and cell death. Endonuclease III is the major DNA glycosylase activity in Escherichia coli that catalyzes the excision of pyrimidines damaged by ring opening or ring saturation, and it also possesses an associated lyase activity that incises the DNA backbone adjacent to apurinic/apyrimidinic sites. During analysis of the area adjacent to the human tuberous sclerosis gene (TSC2) in chromosome region 16p13.3, we identified a gene, OCTS3, that encodes a 1-kb transcript. Analysis of OCTS3 cDNA clones revealed an open reading frame encoding a predicted protein of 34.3 kDa that shares extensive sequence similarity with E. coli endonuclease III and a related enzyme from Schizosaccharomyces pombe, including a conserved active site region and an iron/sulfur domain. The product of the OCTS3 gene was therefore designated hNTH1 (human endonuclease III homolog 1). The hNTH1 protein was overexpressed in E. coli and purified to apparent homogeneity. The recombinant protein had spectral properties indicative of the presence of an iron/sulfur cluster, and exhibited DNA glycosylase activity on double-stranded polydeoxyribonucleotides containing urea and thymine glycol residues, as well as an apurinic/apyrimidinic lyase activity. Our data indicate that hNTH1 is a structural and functional homolog of E. coli endonuclease III, and that this class of enzymes, for repair of oxidatively damaged pyrimidines in DNA, is highly conserved in evolution from microorganisms to human cells. PMID:8990169

  8. Radiation-related information at science exhibitions

    Energy Technology Data Exchange (ETDEWEB)

    Bannai, Tadaaki [Inst. for Environmental Sciences, Rokkasho, Aomori (Japan)

    1999-09-01

    The aim of the present report was to promote an efficient utilization of science museums providing with educational information concerning radiations. Investigations were made on radiation-related materials exhibited at 38 museums including PR event sites between April 1996 and July 1998 mainly located on Kanto and Tohoku area in Japan. The investigation concerned as to whether the displays on radiation-related material (cosmic rays, X-rays, etc) existed or not, and as to the background of the display as well. As the result, 14 locations had no relevant displays, 10 of them not having things about atomic energy at all. The locations belonging to electricity company mostly had displays related to radiations and atomic energy power generation. A spark chamber was exhibited at 9 locations and a cloud chamber at 3 locations, but only one location among them displayed both. Displays on the actual use of X-radiation were found at 4 locations. Needs to prepare further improved displays exist at the sites visited. (S. Ohno)

  9. CERN Inspires Art in Major New Exhibition

    CERN Document Server

    2001-01-01

    Signatures of the Invisible, an exhibition inspired by CERN, opened at the Atlantis Gallery in London on Thursday, 1 March before going on a world tour. The fruit of a close collaboration between CERN and the London Institute, the exhibition brings together works from many leading European contemporary artists. White wooden boxes on a grey floor... the lids opened, unveiling brilliant white light from a bunch of optical fibres carefully stuck together in the shape of a square. Another holds a treasure of lead glass surrounded by enigmatic black mirrors. What's it all about? Signatures of the Invisible, that's what, a joint project organised by the London Institute, one of the world's largest college of art, and our Laboratory. Damien Foresy from the EST workshop putting finishing touches to the spinning tops of French artist Jérôme Basserode. Monica Sand's boxes are just one of the many works based around materials used in particle detection at CERN that was admired at the opening o...

  10. Children's drawings exhibited in the Globe

    CERN Multimedia

    Elizabeth Roe

    2010-01-01

    "Draw Me A Physicist" has been a success. Members of the public visiting the exhibition in the Globe of Science and Innovation have praised the scientific and creative balance the children of neighbouring France and the Canton of Geneva have obtained through their visit to CERN.   The Draw Me a Physicist exhibition in the Globe For a six-month period 9 to 11-year olds from the Pays de Gex, Meyrin, Satigny and Vernier have been able to enjoy a balance between science and art, through drawing and defining their interpretations of a physicist. In May, eight pairs of drawings from each participating class were selected by the schools to be displayed on the second floor of the Globe. Since the images have been put up, the viewers have enjoyed the contrast between the "before" pictures of vibrant Albert Einsteins to the "after" pictures of casual people sitting in an office. The large room in the Globe has been transformed from a hollow shell int...

  11. Exhibiting the Human/Exhibiting the Cyborg: “Who Am I?”

    Directory of Open Access Journals (Sweden)

    Sophia C. Vackimes

    2013-08-01

    Full Text Available The role of the museum in shaping our relationship to science and technology, particularly cyborgization, is illuminated by a close examination of the Who Am I permanent exhibition in the Wellcome Wing of the Science Museum of London. This innovative exhibition raises real questions both about the human-technology-science relationship but also about museography. In the context of the history and current practices of museums engaging contemporary technological developments the evidence suggest that even as the Who am I? exhibit did break somewhat from previous approaches, especially the didactic presentation of the socially useful, it has not changed the feld as a whole.

  12. Impact of homologous recombination on individual cellular radiosensitivity

    International Nuclear Information System (INIS)

    Koch, Kerstin; Wrona, Agnieszka; Dikomey, Ekkehard; Borgmann, Kerstin

    2009-01-01

    Purpose: Individual radiosensitivity as measured with in vitro irradiated lymphocytes using metaphase analysis can predict the risk of normal tissue effects after radiotherapy. This parameter is considered to be primarily determined by the cellular repair capacity of DNA double-strand breaks (DSBs). It is now tested to which extent this capacity also depends on homologous recombination (HR), which is a pathway available when cells are in S/G2 phase. Methods: Experiments were performed with CHO K1 cells, in which HR was suppressed via knock-down of RAD51 using RNA interference (RNAi). RAD51 was measured via western and foci formation, cell survival by colony forming, DSBs by γH2AX foci formation, and chromosomal damage using PCC, G0 or G2 assay. Results: In quiescent G1 cells DSB repair is completed 6 h after irradiation. But there is still a substantial fraction of non-repaired DSBs. Most of these DSBs are repaired when G1 cells are stimulated into cell cycle. Suppression of HR by down-regulation of RAD51 did not affect this repair. In contrast, repair was inhibited when cells were irradiated in late S/G2. In line with these data down-regulation of HR did affect survival of cells irradiated in late S/G2, but not in G1. Conclusions: Individual radiosensitivity as measured for G0/1 cells using metaphase analysis does not depend on homologous recombination

  13. Structural analysis of zwitterionic liquids vs. homologous ionic liquids

    Science.gov (United States)

    Wu, Boning; Kuroda, Kosuke; Takahashi, Kenji; Castner, Edward W.

    2018-05-01

    Zwitterionic liquids (Zw-ILs) have been developed that are homologous to monovalent ionic liquids (ILs) and show great promise for controlled dissolution of cellulosic biomass. Using both high energy X-ray scattering and atomistic molecular simulations, this article compares the bulk liquid structural properties for novel Zw-ILs with their homologous ILs. It is shown that the significant localization of the charges on Zw-ILs leads to charge ordering similar to that observed for conventional ionic liquids with monovalent anions and cations. A low-intensity first sharp diffraction peak in the liquid structure factor S(q) is observed for both the Zw-IL and the IL. This is unexpected since both the Zw-IL and IL have a 2-(2-methoxyethoxy)ethyl (diether) functional group on the cationic imidazolium ring and ether functional groups are known to suppress this peak. Detailed analyses show that this intermediate range order in the liquid structure arises for slightly different reasons in the Zw-IL vs. the IL. For the Zw-IL, the ether tails in the liquid are shown to aggregate into nanoscale domains.

  14. Gimeracil sensitizes cells to radiation via inhibition of homologous recombination

    International Nuclear Information System (INIS)

    Takagi, Masaru; Sakata, Koh-ichi; Someya, Masanori; Tauchi, Hiroshi; Iijima, Kenta; Matsumoto, Yoshihisa; Torigoe, Toshihiko; Takahashi, Akari; Hareyama, Masato; Fukushima, Masakazu

    2010-01-01

    Background and purpose: 5-Chloro-2,4-dihydroxypyridine (Gimeracil) is a component of an oral fluoropyrimidine derivative S-1. Gimeracil is originally added to S-1 to yield prolonged 5-FU concentrations in tumor tissues by inhibiting dihydropyrimidine dehydrogenase, which degrades 5-FU. We found that Gimeracil by itself had the radiosensitizing effect. Methods and materials: We used various cell lines deficient in non-homologous end-joining (NHEJ) or homologous recombination (HR) as well as DLD-1 and HeLa in clonogenic assay. γ-H2AX focus formation and SCneo assay was performed to examine the effects of Gimeracil on DNA double strand break (DSB) repair mechanisms. Results: Results of γ-H2AX focus assay indicated that Gimeracil inhibited DNA DSB repair. It did not sensitize cells deficient in HR but sensitized those deficient in NHEJ. In SCneo assay, Gimeracil reduced the frequency of neo-positive clones. Additionally, it sensitized the cells in S-phase more than in G0/G1. Conclusions: Gimeracil inhibits HR. Because HR plays key roles in the repair of DSBH caused by radiotherapy, Gimeracil may enhance the efficacy of radiotherapy through the suppression of HR-mediated DNA repair pathways.

  15. Protein homology model refinement by large-scale energy optimization.

    Science.gov (United States)

    Park, Hahnbeom; Ovchinnikov, Sergey; Kim, David E; DiMaio, Frank; Baker, David

    2018-03-20

    Proteins fold to their lowest free-energy structures, and hence the most straightforward way to increase the accuracy of a partially incorrect protein structure model is to search for the lowest-energy nearby structure. This direct approach has met with little success for two reasons: first, energy function inaccuracies can lead to false energy minima, resulting in model degradation rather than improvement; and second, even with an accurate energy function, the search problem is formidable because the energy only drops considerably in the immediate vicinity of the global minimum, and there are a very large number of degrees of freedom. Here we describe a large-scale energy optimization-based refinement method that incorporates advances in both search and energy function accuracy that can substantially improve the accuracy of low-resolution homology models. The method refined low-resolution homology models into correct folds for 50 of 84 diverse protein families and generated improved models in recent blind structure prediction experiments. Analyses of the basis for these improvements reveal contributions from both the improvements in conformational sampling techniques and the energy function.

  16. HOMOLOGY MODELING AND MOLECULAR DYNAMICS STUDY OF MYCOBACTERIUM TUBERCULOSIS UREASE

    Directory of Open Access Journals (Sweden)

    Lisnyak Yu. V.

    2017-10-01

    Full Text Available Introduction. M. tuberculosis urease (MTU is an attractive target for chemotherapeutic intervention in tuberculosis by designing new safe and efficient enzyme inhibitors. A prerequisite for designing such inhibitors is an understanding of urease's three-dimensional (3D structure organization. 3D structure of M. tuberculosis urease is unknown. When experimental three-dimensional structure of a protein is not known, homology modeling, the most commonly used computational structure prediction method, is the technique of choice. This paper aimed to build a 3D-structure of M. tuberculosis urease by homology modeling and to study its stability by molecular dynamics simulations. Materials and methods. To build MTU model, five high-resolution X-ray structures of bacterial ureases with three-subunit composition (2KAU, 5G4H, 4UBP, 4СEU, and 4EPB have been selected as templates. For each template five stochastic alignments were created and for each alignment, a three-dimensional model was built. Then, each model was energy minimized and the models were ranked by quality Z-score. The MTU model with highest quality estimation amongst 25 potential models was selected. To further improve structure quality the model was refined by short molecular dynamics simulation that resulted in 20 snapshots which were rated according to their energy and the quality Z-score. The best scoring model having minimum energy was chosen as a final homology model of 3D structure for M. tuberculosis. The final model of MTU was also validated by using PDBsum and QMEAN servers. These checks confirmed good quality of MTU homology model. Results and discussion. Homology model of MTU is a nonamer (homotrimer of heterotrimers, (αβγ3 consisting of 2349 residues. In MTU heterotrimer, sub-units α, β, and γ tightly interact with each other at a surface of approximately 3000 Å2. Sub-unit α contains the enzyme active site with two Ni atoms coordinated by amino acid residues His347, His

  17. Shape-Memory PVDF Exhibiting Switchable Piezoelectricity.

    Science.gov (United States)

    Hoeher, Robin; Raidt, Thomas; Novak, Nikola; Katzenberg, Frank; Tiller, Joerg C

    2015-12-01

    In this study, a material is designed which combines the properties of shape-memory and electroactive polymers. This is achieved by covalent cross-linking of polyvinylidene fluoride. The resulting polymer network exhibits excellent shape-memory properties with a storable strain of 200%, and fixity as well as recovery values of 100%. Programming upon rolling induces the transformation from the nonelectroactive α-phase to the piezoelectric β-phase. The highest β-phase content is found to be 83% for a programming strain of 200% affording a d33 value of -30 pm V(-1). This is in good accordance with literature known values for piezoelectric properties. Thermal triggering this material does not only result in a shape change but also renders the material nonelectroactive. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Applied Gamification in Self-guided Exhibitions

    DEFF Research Database (Denmark)

    Vistisen, Peter; Selvadurai, Vashanth; Krishnasamy, Rameshnath Kala

    2018-01-01

    This paper contributes to the current understanding of applied digital gamification by providing insights from two design cases from the Danish aqua zoo, the North Sea Oceanarium, concerned with self-facilitated exhibitions. Grounded in a short review of the current state of art, we provide two...... empirical case examples, concerning a mobile augmented reality design and an Instagram service. Analyzing the design process behind these cases, we identify some of the challenges arising from applying gamification in practice, and whether these insights verify, extents or contradicts current examples...... of applied gamification research. Specifically, the cases provide insights to the challenge of on-boarding visitors into participating and using the designed products during their visit. In both cases, providing certain incentives for using the app or participating in the Instagram challenge, seemed...

  19. Exhibiting health and medicine as culture

    DEFF Research Database (Denmark)

    Whiteley, Louise; Tybjerg, Karin; Pedersen, Bente Vinge

    2017-01-01

    -being of their visitors, we instead focus on how museums should communicate about health and medicine. Methods: The paper describes three examples of exhibitions at Medical Museion that attempt to display medicine as culture, and draws out three of the key strategies they employ. Results: The three key strategies are: (1......Introduction: This paper discusses the potential role of medical museums in public engagement with health and medicine, based on the work of Medical Museion at the University of Copenhagen. Rather than asking whether cultural venues such as museums can directly improve the well......: There is increasing emphasis on the need for health communication to recognize people’s multiple, lived cultures. We argue that we should also recognize that medical research and practice is itself a form of culture, and as such is multiple and historically shifting. This paper demonstrates that museums are an ideal...

  20. The coordination office at SIREME 2008 exhibition

    International Nuclear Information System (INIS)

    Grotz, Claudia; Cassin, Fabrice; Evrard, Aurelien; Froeding, Veronique; Galaup, Serge; Kaelble, Laure; Persem, Melanie; Regnier, Yannick; )

    2008-01-01

    The French-German office for Renewable energies (OFAEnR) organised several presentations at the occasion of the SIREME International exhibition of renewable energies and energy management. This document brings together these presentations (slides) dealing with: 1 - The new German Renewable Energy Sources Act (EEG) and its impact on wind energy (Claudia Grotz); 2 - Consequences of the July 10, 2006 wind energy tariff bylaw cancelling (Fabrice Cassin); 3 - Wind energy trajectory in France and Germany: a political perspective (Aurelien Evrard); 4 - The wind energy development areas (Veronique Froeding); 5 - A commitment at the heart of our business: renewable energy sources (Serge Galaup); 6 - The wind energy coordination office (Laure Kaelble); 7 - New challenges of the German wind energy market (Melanie Persem); 8 - An industry - a qualification standard (Yannick Regnier)

  1. The Road Transport world exhibition in Paris

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Following the agreement between French and German professionals of automobile and industrial vehicle, the Road Transport world exhibition will take place alternatively in Paris and Hanover. The 1995 meeting has taken place in Paris (September 15-21) and about 20 countries were represented. Road transport is the principal way of goods transportation in France and represent 88% of the traffic explained in tons gross and 70% in tons km. The petroleum dependence of the transportation sector is becoming a worrying problem as the gasoline and diesel fuels taxes will be discussed in the 1996 financial laws project. According to the last ''Worldwide energetic perspectives'' report published by the IEA, in 2010 the transportation sector could absorb more than 60% of the worldwide petroleum consumption. This increase represents a challenge to the petroleum industry to increase the energetic efficiency of the vehicle fuels and the production of diesel fuels, and conversely to reduce the pollution effluents. (J.S.). 4 tabs

  2. Application of an imaging system to a museum exhibition for developing interactive exhibitions

    Science.gov (United States)

    Miyata, Kimiyoshi; Inoue, Yuka; Takiguchi, Takahiro; Tsumura, Norimichi; Nakaguchi, Toshiya; Miyake, Yoichi

    2009-10-01

    In the National Museum of Japanese History, 215,759 artifacts are stored and used for research and exhibitions. In museums, due to the limitation of space in the galleries, a guidance system is required to satisfy visitors' needs and to enhance their understanding of the artifacts. We introduce one exhibition using imaging technology to improve visitors' understanding of a kimono (traditional Japanese clothing) exhibition. In the imaging technology introduced, one data projector, one display with touch panel interface, and magnifiers were used as exhibition tools together with a real kimono. The validity of this exhibition method was confirmed by results from a visitors' interview survey. Second, to further develop the interactive guidance system, an augmented reality system that consisted of cooperation between the projector and a digital video camera was also examined. A white paper board in the observer's hand was used as a projection screen and also as an interface to control the images projected on the board. The basic performance of the proposed system was confirmed; however continuous development was necessary for applying the system to actual exhibitions.

  3. Homologous stress adaptation, antibiotic resistance, and biofilm forming ability of Salmonella enterica serovar Heidelberg (ATCC8326) on different food-contact surfaces following exposure to sub-lethal chlorine concentrations

    Science.gov (United States)

    Salmonella enterica serovar Heidelberg (American Type Culture Collection; ATCC 8326) was examined for the ability to adapt to the homologous stress of chlorine through exposure to increasing chlorine concentrations (25 ppm daily increments) in tryptic soy broth (TSB). The tested strain exhibited an ...

  4. Homologous recombination and non-homologous end-joining repair pathways in bovine embryos with different developmental competence

    International Nuclear Information System (INIS)

    Henrique Barreta, Marcos; Garziera Gasperin, Bernardo; Braga Rissi, Vitor; Cesaro, Matheus Pedrotti de; Ferreira, Rogério; Oliveira, João Francisco de; Gonçalves, Paulo Bayard Dias; Bordignon, Vilceu

    2012-01-01

    This study investigated the expression of genes controlling homologous recombination (HR), and non-homologous end-joining (NHEJ) DNA-repair pathways in bovine embryos of different developmental potential. It also evaluated whether bovine embryos can respond to DNA double-strand breaks (DSBs) induced with ultraviolet irradiation by regulating expression of genes involved in HR and NHEJ repair pathways. Embryos with high, intermediate or low developmental competence were selected based on the cleavage time after in vitro insemination and were removed from in vitro culture before (36 h), during (72 h) and after (96 h) the expected period of embryonic genome activation. All studied genes were expressed before, during and after the genome activation period regardless the developmental competence of the embryos. Higher mRNA expression of 53BP1 and RAD52 was found before genome activation in embryos with low developmental competence. Expression of 53BP1, RAD51 and KU70 was downregulated at 72 h and upregulated at 168 h post-insemination in response to DSBs induced by ultraviolet irradiation. In conclusion, important genes controlling HR and NHEJ DNA-repair pathways are expressed in bovine embryos, however genes participating in these pathways are only regulated after the period of embryo genome activation in response to ultraviolet-induced DSBs.

  5. Homologous recombination and non-homologous end-joining repair pathways in bovine embryos with different developmental competence

    Energy Technology Data Exchange (ETDEWEB)

    Henrique Barreta, Marcos [Universidade Federal de Santa Catarina, Campus Universitario de Curitibanos, Curitibanos, SC (Brazil); Laboratorio de Biotecnologia e Reproducao Animal-BioRep, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Garziera Gasperin, Bernardo; Braga Rissi, Vitor; Cesaro, Matheus Pedrotti de [Laboratorio de Biotecnologia e Reproducao Animal-BioRep, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Ferreira, Rogerio [Centro de Educacao Superior do Oeste-Universidade do Estado de Santa Catarina, Chapeco, SC (Brazil); Oliveira, Joao Francisco de; Goncalves, Paulo Bayard Dias [Laboratorio de Biotecnologia e Reproducao Animal-BioRep, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Bordignon, Vilceu, E-mail: vilceu.bordignon@mcgill.ca [Department of Animal Science, McGill University, Ste-Anne-De-Bellevue, QC (Canada)

    2012-10-01

    This study investigated the expression of genes controlling homologous recombination (HR), and non-homologous end-joining (NHEJ) DNA-repair pathways in bovine embryos of different developmental potential. It also evaluated whether bovine embryos can respond to DNA double-strand breaks (DSBs) induced with ultraviolet irradiation by regulating expression of genes involved in HR and NHEJ repair pathways. Embryos with high, intermediate or low developmental competence were selected based on the cleavage time after in vitro insemination and were removed from in vitro culture before (36 h), during (72 h) and after (96 h) the expected period of embryonic genome activation. All studied genes were expressed before, during and after the genome activation period regardless the developmental competence of the embryos. Higher mRNA expression of 53BP1 and RAD52 was found before genome activation in embryos with low developmental competence. Expression of 53BP1, RAD51 and KU70 was downregulated at 72 h and upregulated at 168 h post-insemination in response to DSBs induced by ultraviolet irradiation. In conclusion, important genes controlling HR and NHEJ DNA-repair pathways are expressed in bovine embryos, however genes participating in these pathways are only regulated after the period of embryo genome activation in response to ultraviolet-induced DSBs.

  6. Exhibition of Stochastic Resonance in Vestibular Perception

    Science.gov (United States)

    Galvan-Garza, R. C.; Clark, T. K.; Merfeld, D. M.; Bloomberg, J. J.; Oman, C. M.; Mulavara, A. P.

    2016-01-01

    Astronauts experience sensorimotor changes during spaceflight, particularly during G-transitions. Post flight sensorimotor changes include spatial disorientation, along with postural and gait instability that may degrade operational capabilities of the astronauts and endanger the crew. A sensorimotor countermeasure that mitigates these effects would improve crewmember safety and decrease risk. The goal of this research is to investigate the potential use of stochastic vestibular stimulation (SVS) as a technology to improve sensorimotor function. We hypothesize that low levels of SVS will improve sensorimotor perception through the phenomenon of stochastic resonance (SR), when the response of a nonlinear system to a weak input signal is enhanced by the application of a particular nonzero level of noise. This study aims to advance the development of SVS as a potential countermeasure by 1) demonstrating the exhibition of stochastic resonance in vestibular perception, a vital component of sensorimotor function, 2) investigating the repeatability of SR exhibition, and 3) determining the relative contribution of the semicircular canals (SCC) and otolith (OTO) organs to vestibular perceptual SR. A constant current stimulator was used to deliver bilateral bipolar SVS via electrodes placed on each of the mastoid processes, as previously done. Vestibular perceptual motion recognition thresholds were measured using a 6-degree of freedom MOOG platform and a 150 trial 3-down/1-up staircase procedure. In the first test session, we measured vestibular perceptual thresholds in upright roll-tilt at 0.2 Hz (SCC+OTO) with SVS ranging from 0-700 µA. In a second test session a week later, we re-measured roll-tilt thresholds with 0, optimal (from test session 1), and 1500 µA SVS levels. A subset of these subjects, plus naive subjects, participated in two additional test sessions in which we measured thresholds in supine roll-rotation at 0.2 Hz (SCC) and upright y-translation at 1 Hz

  7. Electrochemically synthesized amorphous and crystalline nanowires: dissimilar nanomechanical behavior in comparison with homologous flat films

    Science.gov (United States)

    Zeeshan, M. A.; Esqué-de Los Ojos, D.; Castro-Hartmann, P.; Guerrero, M.; Nogués, J.; Suriñach, S.; Baró, M. D.; Nelson, B. J.; Pané, S.; Pellicer, E.; Sort, J.

    2016-01-01

    The effects of constrained sample dimensions on the mechanical behavior of crystalline materials have been extensively investigated. However, there is no clear understanding of these effects in nano-sized amorphous samples. Herein, nanoindentation together with finite element simulations are used to compare the properties of crystalline and glassy CoNi(Re)P electrodeposited nanowires (φ ~ 100 nm) with films (3 μm thick) of analogous composition and structure. The results reveal that amorphous nanowires exhibit a larger hardness, lower Young's modulus and higher plasticity index than glassy films. Conversely, the very large hardness and higher Young's modulus of crystalline nanowires are accompanied by a decrease in plasticity with respect to the homologous crystalline films. Remarkably, proper interpretation of the mechanical properties of the nanowires requires taking the curved geometry of the indented surface and sink-in effects into account. These findings are of high relevance for optimizing the performance of new, mechanically-robust, nanoscale materials for increasingly complex miniaturized devices.The effects of constrained sample dimensions on the mechanical behavior of crystalline materials have been extensively investigated. However, there is no clear understanding of these effects in nano-sized amorphous samples. Herein, nanoindentation together with finite element simulations are used to compare the properties of crystalline and glassy CoNi(Re)P electrodeposited nanowires (φ ~ 100 nm) with films (3 μm thick) of analogous composition and structure. The results reveal that amorphous nanowires exhibit a larger hardness, lower Young's modulus and higher plasticity index than glassy films. Conversely, the very large hardness and higher Young's modulus of crystalline nanowires are accompanied by a decrease in plasticity with respect to the homologous crystalline films. Remarkably, proper interpretation of the mechanical properties of the nanowires

  8. Dynamics of Cellular Proliferation during 'Acute Homologous Disease' in Mice

    Energy Technology Data Exchange (ETDEWEB)

    Vitale, B.; Silobrcic, V.; Jurin, M.; Matosic, M.; Tomazic, Vesna [Laboratory for Transplantation and Tumour Immunology, Department of Biology, Institute Ruder Boskovic, Zagreb, Yugoslavia (Croatia)

    1968-08-15

    CBA mice, lethally irradiated and injected with 20 x 10{sup 6} bone-marrow cells derived from C57BL donors, develop a chronic form of 'homologous disease' and die between 20 and 40 days after treatment. If 10 x 10{sup 6} lymph node cells are added to the bone-marrow suspension, all recipients develop 'acute' homologous disease and die 6 to 10 days after irradiation. Different parameters of the disease were systematically observed. Among them, changes in spleen weight indicated early cell proliferation, which reached its maximum on day 4 and progressively decreased later on. Chromosomal analysis showed that all dividing cells in the spleen were of donor origin. Their number decreased concomitantly with the shrinkage and devastation of the organ, which started on day 6. The period of devastation of the spleen fully corresponds to the time in which all animals die. The use of cyclophosphamide in the treatment of 'acute' homologous disease transformed the disease into a chronic form with a mortality very similar to that obtained when only bone-marrow cells were injected. Among other effects, treatment with cyclophosphamide prevented early proliferation of donor cells in the spleen, and delayed spleen weight increase for about 10 days. After that period spleen weight increased, reaching its maximum on day 12. At first only donor type cells could be detected, but towards the end of the period in which spleen weight increase was registered host type cells appeared among the cells in mitosis. Their number gradually increased, and in some cases the majority or all of the dividing cells were of the host type. After a transitional decrease in spleen weight, another peak in cellular proliferation consisting of either host or donor or both types of cells was observed about day 30. In spite of the observed irregularities in the origin of dividing cells, all animals died by day 40 after application of cyclophosphamide. The relationship between proliferation of injected lymph node

  9. VIRTUAL EXHIBITION AND FRUITION OF ARCHAEOLOGICAL FINDS

    Directory of Open Access Journals (Sweden)

    A. M. Manferdini

    2012-09-01

    Full Text Available During the last two decades, since digital technologies have become more sophisticated in acquiring real data and building faithful copies of them, their improvements have suggested interesting applications in the field of valorisation of Historical, Cultural and Artistic Heritage, with significant consequences in the share and widespread of knowledge. But although several technologies and methodologies for 3d digitization have recently been developed and improved, the lack of a standard procedure and the costs connected to their use still doesn't encourage the systematic digital acquisition of wide collections and heritage. The aim of this paper is to show the state of the art of a project whose aim is to provide a methodology and a procedure to create digital reproductions of artefacts for Institutions called to preserve, manage and enhance the fruition of archaeological finds inside museums or through digital exhibitions. Our project’s aim is to find the most suitable procedure to digitally acquire archaeo logical artefacts that usually have small dimensions and have very complex and detailed surfaces. Within our methodology, particular attention has been paid to the use of widely shared and open-source visualization systems that enhance the involvement of the user by emphasizing three-dimensional characteristics of artefacts through virtual reality.

  10. Caffeine suppresses homologous recombination through interference with RAD51-mediated joint molecule formation

    Science.gov (United States)

    Zelensky, Alex N.; Sanchez, Humberto; Ristic, Dejan; Vidic, Iztok; van Rossum-Fikkert, Sari E.; Essers, Jeroen; Wyman, Claire; Kanaar, Roland

    2013-01-01

    Caffeine is a widely used inhibitor of the protein kinases that play a central role in the DNA damage response. We used chemical inhibitors and genetically deficient mouse embryonic stem cell lines to study the role of DNA damage response in stable integration of the transfected DNA and found that caffeine rapidly, efficiently and reversibly inhibited homologous integration of the transfected DNA as measured by several homologous recombination-mediated gene-targeting assays. Biochemical and structural biology experiments revealed that caffeine interfered with a pivotal step in homologous recombination, homologous joint molecule formation, through increasing interactions of the RAD51 nucleoprotein filament with non-homologous DNA. Our results suggest that recombination pathways dependent on extensive homology search are caffeine-sensitive and stress the importance of considering direct checkpoint-independent mechanisms in the interpretation of the effects of caffeine on DNA repair. PMID:23666627

  11. Future trypanosomatid phylogenies: refined homologies, supertrees and networks

    Directory of Open Access Journals (Sweden)

    Stothard JR

    2000-01-01

    Full Text Available There has been good progress in inferring the evolutionary relationships within trypanosomes from DNA data as until relatively recently, many relationships have remained rather speculative. Ongoing molecular studies have provided data that have adequately shown Trypanosoma to be monophyletic and, rather surprisingly, that there are sharply contrasting levels of genetic variation within and between the major trypanosomatid groups. There are still, however, areas of research that could benefit from further development and resolution that broadly fall upon three questions. Are the current statements of evolutionary homology within ribosomal small sub-unit genes in need of refinement? Can the published phylograms be expanded upon to form `supertrees' depicting further relationships? Does a bifurcating tree structure impose an untenable dogma upon trypanosomatid phylogeny where hybridisation or reticulate evolutionary steps have played a part? This article briefly addresses these three questions and, in so doing, hopes to stimulate further interest in the molecular evolution of the group.

  12. Development and characterization of a homologous radioimmunoassay for equine prolactin

    International Nuclear Information System (INIS)

    Roser, J.F.; Chang, Y.S.; Papkoff, H.; Li, C.H.

    1984-01-01

    A specific and sensitive homologous radioimmunoassay has been developed for equine prolactin, suitable for measuring prolactin concentrations in serum of horses. The sensitivity of the assay ranged from 0.4 to 0.6 ng/ml and the intra- and inter-assay coefficients of variation averaged 6.9 and 15.4%, respectively, for five doses of hormone. Cross-reactivity with other mammalian and nonmammalian prolactins and growth hormones was less than 20 and 0.3%, respectively. Cross-reactivity with equine growth hormone was less than 0.07%. Equine serum and pituitary extracts showed parallel dilution-response curves with equine prolactin. The percentage recovery of exogenous equine prolactin in serum was 89%. Preliminary analysis of several physiological samples (stallions, pregnant, and nonpregnant mares) yielded values from 0.6 to 12.0 ng/ml

  13. Identification of rodent homologs of hepatitis C virus and pegiviruses

    DEFF Research Database (Denmark)

    Kapoor, Amit; Simmonds, Peter; Scheel, Troels K H

    2013-01-01

    UNLABELLED: Hepatitis C virus (HCV) and human pegivirus (HPgV or GB virus C) are globally distributed and infect 2 to 5% of the human population. The lack of tractable-animal models for these viruses, in particular for HCV, has hampered the study of infection, transmission, virulence, immunity...... into the origins of human infections and enhances our ability to study their pathogenesis and explore preventive and therapeutic interventions. Horses are the only reported host of nonprimate homologs of hepatitis C virus (HCV). Here, we report the discovery of HCV-like viruses in wild rodents. The majority of HCV...... of small-animal models for HCV, the most common infectious cause of liver failure and hepatocellular carcinoma after hepatitis B virus, and help to explore the health relevance of the highly prevalent human pegiviruses....

  14. The tedious task of finding homologous noncoding RNA genes

    DEFF Research Database (Denmark)

    Menzel, Karl Peter; Gorodkin, Jan; Stadler, Peter F

    2009-01-01

    User-driven in silico RNA homology search is still a nontrivial task. In part, this is the consequence of a limited precision of the computational tools in spite of recent exciting progress in this area, and to a certain extent, computational costs are still problematic in practice. An important......, and as we argue here, dominating issue is the dependence on good curated (secondary) structural alignments of the RNAs. These are often hard to obtain, not so much because of an inherent limitation in the available data, but because they require substantial manual curation, an effort that is rarely...... acknowledged. Here, we qualitatively describe a realistic scenario for what a "regular user" (i.e., a nonexpert in a particular RNA family) can do in practice, and what kind of results are likely to be achieved. Despite the indisputable advances in computational RNA biology, the conclusion is discouraging...

  15. On the homology of the shoulder girdle in turtles.

    Science.gov (United States)

    Nagashima, Hiroshi; Sugahara, Fumiaki; Takechi, Masaki; Sato, Noboru; Kuratani, Shigeru

    2015-05-01

    The shoulder girdle in turtles is encapsulated in the shell and has a triradiate morphology. Due to its unique configuration among amniotes, many theories have been proposed about the skeletal identities of the projections for the past two centuries. Although the dorsal ramus represents the scapular blade, the ventral two rami remain uncertain. In particular, the ventrorostral process has been compared to a clavicle, an acromion, and a procoracoid based on its morphology, its connectivity to the rest of the skeleton and to muscles, as well as with its ossification center, cell lineage, and gene expression. In making these comparisons, the shoulder girdle skeleton of anurans has often been used as a reference. This review traces the history of the debate on the homology of the shoulder girdle in turtles. And based on the integrative aspects of developmental biology, comparative morphology, and paleontology, we suggest acromion and procoracoid identities for the two ventral processes. © 2014 Wiley Periodicals, Inc.

  16. Homology of yeast photoreactivating gene fragment with human genomic digests

    International Nuclear Information System (INIS)

    Meechan, P.J.; Milam, K.M.; Cleaver, J.E.

    1984-01-01

    Enzymatic photoreactivation of UV-induced DNA lesions has been demonstrated for a variety of prokaryotic and eukaryotic organisms. Its presence in placental mammals, however, has not been clearly established. The authors attempted to resolve this question by assaying for the presence (or absence) of sequences in human DNA complimentary to a fragment of the photoreactivating gene from S. cerevisiae that has recently been cloned. In another study, DNA from human, chick E. coli and yeast cells was digested with either HindIII of BglII, electrophoresed on a 0.5% agarose gel, transferred (Southern blot) to a nylon membrane and probed for homology against a Sau3A restriction fragment from S. cerevisiae that compliments phr/sup -/ cells. Hybridization to human DNA digests was observed only under relatively non-stringent conditions indicating the gene is not conserved in placental mammals. These results are correlated with current literature data concerning photoreactivating enzymes

  17. Internal and External Reconnection Series Homologous Solar Flares

    Science.gov (United States)

    Sterling, Alphonse C.; Moore, Ronald L.

    2001-01-01

    Using data from the extreme ultraviolet imaging telescope (EIT) on SOHO and the soft X-ray telescope (SXT) on Yohkoh, we examine a series of morphologically homologous solar flares occurring in National Oceanic and Atmospheric Administration (NOAA) active region 8210 over May 1-2, 1998. An emerging flux region (EFR) impacted against a sunspot to the west and next to a coronal hole to the east is the source of the repeated flaring. An SXT sigmoid parallels the EFR's neutral line at the site of the initial flaring in soft X rays. In EIT each flaring episode begins with the formation of a crinkle pattern external to the EFR. These EIT crinkles move out from, and then in toward, the EFR with velocities approx. 20 km/ s. A shrinking and expansion of the width of the coronal hole coincides with the crinkle activity, and generation and evolution of a postflare loop system begins near the time of crinkle formation. Using a schematic based on magnetograms of the region, we suggest that these observations are consistent with the standard reconnection-based model for solar eruptions but are modified by the presence of the additional magnetic fields of the sunspot and coronal hole. In the schematic, internal reconnection begins inside of the EFR-associated fields, unleashing a flare, postflare loops, and a coronal mass ejection (CME). External reconnection, first occurring between the escaping CME and the coronal hole field and second occurring between fields formed as a result of the first external reconnection, results in the EIT crinkles and changes in the coronal hole boundary. By the end of the second external reconnection, the initial setup is reinstated; thus the sequence can repeat, resulting in morphologically homologous eruptions. Our inferred magnetic topology is similar to that suggested in the "breakout model" of eruptions although we cannot determine if our eruptions are released primarily by the breakout mechanism (external reconnection) or, alternatively

  18. DNA damage, homology-directed repair, and DNA methylation.

    Directory of Open Access Journals (Sweden)

    Concetta Cuozzo

    2007-07-01

    Full Text Available To explore the link between DNA damage and gene silencing, we induced a DNA double-strand break in the genome of Hela or mouse embryonic stem (ES cells using I-SceI restriction endonuclease. The I-SceI site lies within one copy of two inactivated tandem repeated green fluorescent protein (GFP genes (DR-GFP. A total of 2%-4% of the cells generated a functional GFP by homology-directed repair (HR and gene conversion. However, approximately 50% of these recombinants expressed GFP poorly. Silencing was rapid and associated with HR and DNA methylation of the recombinant gene, since it was prevented in Hela cells by 5-aza-2'-deoxycytidine. ES cells deficient in DNA methyl transferase 1 yielded as many recombinants as wild-type cells, but most of these recombinants expressed GFP robustly. Half of the HR DNA molecules were de novo methylated, principally downstream to the double-strand break, and half were undermethylated relative to the uncut DNA. Methylation of the repaired gene was independent of the methylation status of the converting template. The methylation pattern of recombinant molecules derived from pools of cells carrying DR-GFP at different loci, or from an individual clone carrying DR-GFP at a single locus, was comparable. ClustalW analysis of the sequenced GFP molecules in Hela and ES cells distinguished recombinant and nonrecombinant DNA solely on the basis of their methylation profile and indicated that HR superimposed novel methylation profiles on top of the old patterns. Chromatin immunoprecipitation and RNA analysis revealed that DNA methyl transferase 1 was bound specifically to HR GFP DNA and that methylation of the repaired segment contributed to the silencing of GFP expression. Taken together, our data support a mechanistic link between HR and DNA methylation and suggest that DNA methylation in eukaryotes marks homologous recombined segments.

  19. Oral Region Homologies in Paleozoic Crinoids and Other Plesiomorphic Pentaradial Echinoderms

    OpenAIRE

    Kammer, Thomas W.; Sumrall, Colin D.; Zamora, Samuel; Ausich, William I.; Deline, Bradley

    2013-01-01

    The phylogenetic relationships between major groups of plesiomorphic pentaradial echinoderms, the Paleozoic crinoids, blastozoans, and edrioasteroids, are poorly understood because of a lack of widely recognized homologies. Here, we present newly recognized oral region homologies, based on the Universal Elemental Homology model for skeletal plates, in a wide range of fossil taxa. The oral region of echinoderms is mainly composed of the axial, or ambulacral, skeleton, which apparently evolved ...

  20. 77 FR 31420 - Culturally Significant Objects Imported for Exhibition

    Science.gov (United States)

    2012-05-25

    ... also determine that the exhibition or display of the exhibit objects at The Museum of Modern Art, New...: Game Plan'' imported from abroad for temporary exhibition within the United States, are of cultural...

  1. Characterization of Catalase from Psychrotolerant Psychrobacter piscatorii T-3 Exhibiting High Catalase Activity

    Science.gov (United States)

    Kimoto, Hideyuki; Yoshimune, Kazuaki; Matsuyma, Hidetoshi; Yumoto, Isao

    2012-01-01

    A psychrotolerant bacterium, strain T-3 (identified as Psychrobacter piscatorii), that exhibited an extraordinarily high catalase activity was isolated from the drain pool of a plant that uses H2O2 as a bleaching agent. Its cell extract exhibited a catalase activity (19,700 U·mg protein−1) that was higher than that of Micrococcus luteus used for industrial catalase production. Catalase was approximately 10% of the total proteins in the cell extract of the strain. The catalase (PktA) was purified homogeneously by only two purification steps, anion exchange and hydrophobic chromatographies. The purified catalase exhibited higher catalytic efficiency and higher sensitivity of activity at high temperatures than M. luteus catalase. The deduced amino acid sequence showed the highest homology with catalase of Psycrobacter cryohalolentis, a psychrotolelant bacterium obtained from Siberian permafrost. These findings suggest that the characteristics of the PktA molecule reflected the taxonomic relationship of the isolate as well as the environmental conditions (low temperatures and high concentrations of H2O2) under which the bacterium survives. Strain T-3 efficiently produces a catalase (PktA) at a higher rate than Exiguobacterium oxidotolerans, which produces a very strong activity of catalase (EktA) at a moderate rate, in order to adapt to high concentration of H2O2. PMID:22408420

  2. Homologous series of induced early mutants in Indica rice. Pt.3: The relationship between the induction of homologous series of early mutants and its different pedigree

    International Nuclear Information System (INIS)

    Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

    2002-01-01

    The percentage of homologous series of early mutants (PHSEM) induced by irradiation was closely related to its pedigree. This study showed that PHSEM for varieties with the same pedigree were similar, and there were three different level of dominance (high, low and normal) in the homologous series induced from different pedigree. The PHSEM for varieties derived form distant-relative-parents were higher than that derived from close-relative-parents. There was the dominance pedigree for the induction of homologous series of early mutants. IR8(Peta x DGWG), IR127 (Cpslo x Sigadis) and IR24 (IR8 x IR127) were dominant pedigree, and varieties derived from them could be easily induced the homologous series of early mutants

  3. Multi-Homologous Recombination-Based Gene Manipulation in the Rice Pathogen Fusarium fujikuroi

    Directory of Open Access Journals (Sweden)

    In Sun Hwang

    2016-06-01

    Full Text Available Gene disruption by homologous recombination is widely used to investigate and analyze the function of genes in Fusarium fujikuroi, a fungus that causes bakanae disease and root rot symptoms in rice. To generate gene deletion constructs, the use of conventional cloning methods, which rely on restriction enzymes and ligases, has had limited success due to a lack of unique restriction enzyme sites. Although strategies that avoid the use of restriction enzymes have been employed to overcome this issue, these methods require complicated PCR steps or are frequently inefficient. Here, we introduce a cloning system that utilizes multi-fragment assembly by In-Fusion to generate a gene disruption construct. This method utilizes DNA fragment fusion and requires only one PCR step and one reaction for construction. Using this strategy, a gene disruption construct for Fusarium cyclin C1 (FCC1 , which is associated with fumonisin B1 biosynthesis, was successfully created and used for fungal transformation. In vivo and in vitro experiments using confirmed fcc1 mutants suggest that fumonisin production is closely related to disease symptoms exhibited by F. fujikuroi strain B14. Taken together, this multi-fragment assembly method represents a simpler and a more convenient process for targeted gene disruption in fungi.

  4. A multidimensional strategy to detect polypharmacological targets in the absence of structural and sequence homology.

    Science.gov (United States)

    Durrant, Jacob D; Amaro, Rommie E; Xie, Lei; Urbaniak, Michael D; Ferguson, Michael A J; Haapalainen, Antti; Chen, Zhijun; Di Guilmi, Anne Marie; Wunder, Frank; Bourne, Philip E; McCammon, J Andrew

    2010-01-22

    Conventional drug design embraces the "one gene, one drug, one disease" philosophy. Polypharmacology, which focuses on multi-target drugs, has emerged as a new paradigm in drug discovery. The rational design of drugs that act via polypharmacological mechanisms can produce compounds that exhibit increased therapeutic potency and against which resistance is less likely to develop. Additionally, identifying multiple protein targets is also critical for side-effect prediction. One third of potential therapeutic compounds fail in clinical trials or are later removed from the market due to unacceptable side effects often caused by off-target binding. In the current work, we introduce a multidimensional strategy for the identification of secondary targets of known small-molecule inhibitors in the absence of global structural and sequence homology with the primary target protein. To demonstrate the utility of the strategy, we identify several targets of 4,5-dihydroxy-3-(1-naphthyldiazenyl)-2,7-naphthalenedisulfonic acid, a known micromolar inhibitor of Trypanosoma brucei RNA editing ligase 1. As it is capable of identifying potential secondary targets, the strategy described here may play a useful role in future efforts to reduce drug side effects and/or to increase polypharmacology.

  5. Widespread presence of human BOULE homologs among animals and conservation of their ancient reproductive function.

    Directory of Open Access Journals (Sweden)

    Chirag Shah

    2010-07-01

    Full Text Available Sex-specific traits that lead to the production of dimorphic gametes, sperm in males and eggs in females, are fundamental for sexual reproduction and accordingly widespread among animals. Yet the sex-biased genes that underlie these sex-specific traits are under strong selective pressure, and as a result of adaptive evolution they often become divergent. Indeed out of hundreds of male or female fertility genes identified in diverse organisms, only a very small number of them are implicated specifically in reproduction in more than one lineage. Few genes have exhibited a sex-biased, reproductive-specific requirement beyond a given phylum, raising the question of whether any sex-specific gametogenesis factors could be conserved and whether gametogenesis might have evolved multiple times. Here we describe a metazoan origin of a conserved human reproductive protein, BOULE, and its prevalence from primitive basal metazoans to chordates. We found that BOULE homologs are present in the genomes of representative species of each of the major lineages of metazoans and exhibit reproductive-specific expression in all species examined, with a preponderance of male-biased expression. Examination of Boule evolution within insect and mammalian lineages revealed little evidence for accelerated evolution, unlike most reproductive genes. Instead, purifying selection was the major force behind Boule evolution. Furthermore, loss of function of mammalian Boule resulted in male-specific infertility and a global arrest of sperm development remarkably similar to the phenotype in an insect boule mutation. This work demonstrates the conservation of a reproductive protein throughout eumetazoa, its predominant testis-biased expression in diverse bilaterian species, and conservation of a male gametogenic requirement in mice. This shows an ancient gametogenesis requirement for Boule among Bilateria and supports a model of a common origin of spermatogenesis.

  6. Damping at high homologous temperature in pure Cd, In, Pb, and Sn

    International Nuclear Information System (INIS)

    Cook, L.S.; Lakes, R.S.

    1995-01-01

    Typically, if a material possesses the stiffness necessary to be considered a structural material, its damping is low. Conversely, materials with high damping usually do not possess the stiffness necessary to be considered a structural material. Candidate materials for the high stiffness-low damping phase exist in abundance, whereas candidate materials for the moderate stiffness-high damping phase remain to be identified. One possible class of candidate materials for the moderate stiffness-high damping phase is metals at high homologous temperatures. Shear moduli of the specimens at 100 Hz are as follows: 4.1 GPa for indium, 5.7 GPa for lead, 15.7 GPa for tin, and 20.7 GPa for cadmium. Considering the behavior typical of metals, one may think of In and Pb as relatively compliant, while Sn and Cd could be called moderately stiff. The results are of some technological interest in view of the utility of materials with moderately high stiffness and damping. The combination of moderate stiffness and reasonably high loss tangent makes Cd the most promising metal tested with respect to technological applications. The shear modulus of Cd was highest of the metals tested (and very near that of aluminum (G = 27 GPa), which exhibits a loss tangent of about 0.001 at room temperature). The loss tangent of Cd at audio-frequencies was as high or higher than that of the other metals. In addition, frequency dependence of loss tangent was not as large as that observed in the other metals. No clear pattern relating damping to melting point emerged. An understanding in terms of viscoelastic mechanisms is not forthcoming at this time. Among the metal studied, cadmium exhibited a substantial loss tangent of 0.03 to 0.04 over much of the audio range, combined with a moderate stiffness, G = 20.7 GPa

  7. Homologous desensitization of adenylate cyclase: the role of β-adrenergic receptor phosphorylation and dephosphorylation

    International Nuclear Information System (INIS)

    Sibley, D.R.; Strasser, R.H.; Daniel, K.; Lefkowitz, R.J.

    1986-01-01

    The authors utilized the frog erythrocyte (FE) as a β-adreneric receptor (βAR) model system in which to study homologous desensitization. Preincubation with isoproterenol (ISO) leads to a 50% decline in ISO-stimulated adenylate cyclase (AC) activity without significant changes in basal, PGE 1 -, NaF-, GppNHp-, forskolin-, or MnCl 2 -stimulated AC activities. ISO treatment also induces the sequestration of βAR from the cell surface as evidenced by a 35% decline in [ 3 H]CGP-12177 binding sites on the surface of intact FE. Treatment of intact FE with ISO also promotes βAR phosphorylation to 2 mol PO 4 /mol of βAR. At 25 0 C, the time courses of ISO-induced AC desensitization, βAR sequestration and βAR phosphorylation are identical occurring without a lag and exhibiting a t 1/2 of 30 min and a maximal response at 2.5 hrs. The sequestered βAR can be partially recovered upon cell lysis in a light membrane fraction (LMF), separable from the plasma membranes using sucrose gradients or differential centrifugation. βAR phosphorylation is reversed in the sequestered LMF exhibiting a PO 4 /βAR stoichiometry of 0.7 mol/mol - similar to that observed under basal conditions. These data suggest that phosphorylation of βAR in the plasma membrane promotes their translocation away from the cell surface into a sequestered membrane domain where the phosphorylation is reversed, thus, enabling the return of βAR back to the cell surface and recoupling with AC

  8. Insights into hydrocarbon formation by nitrogenase cofactor homologs.

    Science.gov (United States)

    Lee, Chi Chung; Hu, Yilin; Ribbe, Markus W

    2015-04-14

    The L-cluster is an all-iron homolog of nitrogenase cofactors. Driven by europium(II) diethylenetriaminepentaacetate [Eu(II)-DTPA], the isolated L-cluster is capable of ATP-independent reduction of CO and CN(-) to C1 to C4 and C1 to C6 hydrocarbons, respectively. Compared to its cofactor homologs, the L-cluster generates considerably more CH4 from the reduction of CO and CN(-), which could be explained by the presence of a "free" Fe atom that is "unmasked" by homocitrate as an additional site for methanation. Moreover, the elevated CH4 formation is accompanied by a decrease in the amount of longer hydrocarbons and/or the lengths of the hydrocarbon products, illustrating a competition between CH4 formation/release and C-C coupling/chain extension. These observations suggest the possibility of designing simpler synthetic clusters for hydrocarbon formation while establishing the L-cluster as a platform for mechanistic investigations of CO and CN(-) reduction without complications originating from the heterometal and homocitrate components. Nitrogenase is a metalloenzyme that is highly complex in structure and uniquely versatile in function. It catalyzes two reactions that parallel two important industrial processes: the reduction of nitrogen to ammonia, which parallels the Haber-Bosch process in ammonia production, and the reduction of carbon monoxide to hydrocarbons, which parallels the Fischer-Tropsch process in fuel production. Thus, the significance of nitrogenase can be appreciated from the perspective of the useful products it generates: (i) ammonia, the "fixed" nitrogen that is essential for the existence of the entire human population; and (ii) hydrocarbons, the "recycled" carbon fuel that could be used to directly address the worldwide energy shortage. This article provides initial insights into the catalytic characteristics of various nitrogenase cofactors in hydrocarbon formation. The reported assay system provides a useful tool for mechanistic

  9. Homologous Basal Ganglia Network Models in Physiological and Parkinsonian Conditions

    Directory of Open Access Journals (Sweden)

    Jyotika Bahuguna

    2017-08-01

    Full Text Available The classical model of basal ganglia has been refined in recent years with discoveries of subpopulations within a nucleus and previously unknown projections. One such discovery is the presence of subpopulations of arkypallidal and prototypical neurons in external globus pallidus, which was previously considered to be a primarily homogeneous nucleus. Developing a computational model of these multiple interconnected nuclei is challenging, because the strengths of the connections are largely unknown. We therefore use a genetic algorithm to search for the unknown connectivity parameters in a firing rate model. We apply a binary cost function derived from empirical firing rate and phase relationship data for the physiological and Parkinsonian conditions. Our approach generates ensembles of over 1,000 configurations, or homologies, for each condition, with broad distributions for many of the parameter values and overlap between the two conditions. However, the resulting effective weights of connections from or to prototypical and arkypallidal neurons are consistent with the experimental data. We investigate the significance of the weight variability by manipulating the parameters individually and cumulatively, and conclude that the correlation observed between the parameters is necessary for generating the dynamics of the two conditions. We then investigate the response of the networks to a transient cortical stimulus, and demonstrate that networks classified as physiological effectively suppress activity in the internal globus pallidus, and are not susceptible to oscillations, whereas parkinsonian networks show the opposite tendency. Thus, we conclude that the rates and phase relationships observed in the globus pallidus are predictive of experimentally observed higher level dynamical features of the physiological and parkinsonian basal ganglia, and that the multiplicity of solutions generated by our method may well be indicative of a natural

  10. Studies of Flerovium and Element 115 Homologs with Macrocyclic Extractants

    Energy Technology Data Exchange (ETDEWEB)

    Despotopulos, John D. [Univ. of Nevada, Las Vegas, NV (United States)

    2015-03-12

    Study of the chemistry of the heaviest elements, Z ≥ 104, poses a unique challenge due to their low production cross-sections and short half-lives. Chemistry also must be studied on the one-atom-at-a-time scale, requiring automated, fast, and very efficient chemical schemes. Recent studies of the chemical behavior of copernicium (Cn, element 112) and flerovium (Fl, element 114) together with the discovery of isotopes of these elements with half-lives suitable for chemical studies have spurred a renewed interest in the development of rapid systems designed to study the chemical properties of elements with Z ≥ 114. This dissertation explores both extraction chromatography and solvent extraction as methods for development of a rapid chemical separation scheme for the homologs of flerovium (Pb, Sn, Hg) and element 115 (Bi, Sb), with the goal of developing a chemical scheme that, in the future, can be applied to on-line chemistry of both Fl and element 115. Carrier-free radionuclides, used in these studies, of the homologs of Fl and element 115 were obtained by proton activation of high-purity metal foils at the Lawrence Livermore National Laboratory (LLNL) Center for Accelerator Mass Spectrometry (CAMS): natIn(p,n)113Sn, natSn(p,n)124Sb, and Au(p,n)197m,gHg. The carrier-free activity was separated from the foils by novel separation schemes based on ion exchange and extraction chromatography techniques. Carrier-free Pb and Bi isotopes were obtained from development of a novel generator based on cation exchange chromatography using the 232U parent to generate 212Pb and 212Bi. Macrocyclic extractants, specifically crown ethers and their derivatives, were chosen for these studies; crown ethers show high selectivity for metal ions. Finally. a potential chemical system for Fl was established based on the Eichrom Pb resin, and insight to an improved system based on thiacrown ethers is

  11. Combined HQSAR, topomer CoMFA, homology modeling and docking studies on triazole derivatives as SGLT2 inhibitors.

    Science.gov (United States)

    Yu, Shuling; Yuan, Jintao; Zhang, Yi; Gao, Shufang; Gan, Ying; Han, Meng; Chen, Yuewen; Zhou, Qiaoqiao; Shi, Jiahua

    2017-06-01

    Sodium-glucose cotransporter 2 (SGLT2) is a promising target for diabetes therapy. We aimed to develop computational approaches to identify structural features for more potential SGLT2 inhibitors. In this work, 46 triazole derivatives as SGLT2 inhibitors were studied using a combination of several approaches, including hologram quantitative structure-activity relationships (HQSAR), topomer comparative molecular field analysis (CoMFA), homology modeling, and molecular docking. HQSAR and topomer CoMFA were used to construct models. Molecular docking was conducted to investigate the interaction of triazole derivatives and homology modeling of SGLT2, as well as to validate the results of the HQSAR and topomer CoMFA models. The most effective HQSAR and topomer CoMFA models exhibited noncross-validated correlation coefficients of 0.928 and 0.891 for the training set, respectively. External predictions were made successfully on a test set and then compared with previously reported models. The graphical results of HQSAR and topomer CoMFA were proven to be consistent with the binding mode of the inhibitors and SGLT2 from molecular docking. The models and docking provided important insights into the design of potent inhibitors for SGLT2.

  12. Chronic exposure to sublethal doses of radiation mimetic ZeocinTM selects for clones deficient in homologous recombination

    International Nuclear Information System (INIS)

    Delacote, Fabien; Deriano, Ludovic; Lambert, Sarah; Bertrand, Pascale; Saintigny, Yannick; Lopez, Bernard S.

    2007-01-01

    DNA double-strand breaks (DSBs) are highly toxic lesions leading to genome variability/instability. The balance between homologous recombination (HR) and non-homologous end-joining (NHEJ), two alternative DSB repair systems, is essential to ensure genome maintenance in mammalian cells. Here, we transfected CHO hamster cells with the pcDNA TM 3.1/Zeo plasmid, and selected transfectants with Zeocin TM , a bleomycin analog which produces DSBs. Despite the presence of a Zeocin TM resistance gene in pcDNA TM 3.1/Zeo, Zeocin TM induced 8-10 γ-H2AX foci per cell. This shows that the Zeocin TM resistance gene failed to fully detoxify cells treated with Zeocin TM , and that during selection cells were submitted to a chronic sublethal DSB stress. Selected clones show decreases in both spontaneous and induced intrachromosomal HR. In contrast, in an in vitro assay, these clones show an increase in NHEJ products specific to the KU86 pathway. We selected cells, in the absence of pcDNA TM 3.1/Zeo, with low and sublethal doses of Zeocin TM , producing a mean 8-10 γ-H2AX foci per cell. Newly selected clones exhibited similar phenotypes: HR decrease accompanied by an increase in KU86-dependent NHEJ efficiency. Thus chronic exposure to sublethal numbers of DSBs selects cells whose HR versus NHEJ balance is altered. This may well have implications for radio- and chemotherapy, and for management of environmental hazards

  13. Novel inhibitors induce large conformational changes of GAB1 pleckstrin homology domain and kill breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Lu Chen

    2015-01-01

    Full Text Available The Grb2-associated binding protein 1 (GAB1 integrates signals from different signaling pathways and is over-expressed in many cancers, therefore representing a new therapeutic target. In the present study, we aim to target the pleckstrin homology (PH domain of GAB1 for cancer treatment. Using homology models we derived, high-throughput virtual screening of five million compounds resulted in five hits which exhibited strong binding affinities to GAB1 PH domain. Our prediction of ligand binding affinities is also in agreement with the experimental KD values. Furthermore, molecular dynamics studies showed that GAB1 PH domain underwent large conformational changes upon ligand binding. Moreover, these hits inhibited the phosphorylation of GAB1 and demonstrated potent, tumor-specific cytotoxicity against MDA-MB-231 and T47D breast cancer cell lines. This effort represents the discovery of first-in-class GAB1 PH domain inhibitors with potential for targeted breast cancer therapy and provides novel insights into structure-based approaches to targeting this protein.

  14. 77 FR 31909 - Culturally Significant Objects Imported for Exhibition

    Science.gov (United States)

    2012-05-30

    ... exhibition ``50th Anniversary Remembrance of the Tragedy at Orly,'' imported from abroad by the High Museum of Art for temporary exhibition within the United States, is of cultural significance. The object is... exhibition or display of the exhibit object at the High Museum of Art in Atlanta, Georgia from on or about...

  15. Temporary and Travelling Exhibitions. Museums and Monuments, X.

    Science.gov (United States)

    Daifuku, Hiroshi; And Others

    The permanent exhibition, the most typical form of museum exhibition, has failed to attract repeated visitation, since visitors quickly become familiar with the objects shown. The temporary exhibition evolved as a result for the need of repeated visitation. The temporary exhibition, set up for a period of one to six months, introduces fresh…

  16. Designing immersion exhibits as border-crossing environments

    DEFF Research Database (Denmark)

    Mortensen, Marianne Foss

    2010-01-01

    be applied to achieve an understanding of the immersion exhibit form. The argument proceeds by demonstrating how the characteristics of immersion exhibits, and visitors to them, classify them as microcultures, and examining the implications of this for exhibit design using a hypothetical immersion exhibit...

  17. Topological data analysis as a morphometric method: using persistent homology to demarcate a leaf morphospace

    Science.gov (United States)

    Current morphometric methods that comprehensively measure shape cannot compare the disparate leaf shapes found in flowering plants and are sensitive to processing artifacts. Here we describe a persistent homology approach to measuring shape. Persistent homology is a topological method (concerned wit...

  18. Homology building as a means to define antigenic epitopes on dihydrofolate reductase (DHFR) from Plasmodium falciparum

    DEFF Research Database (Denmark)

    Alifrangis, Michael; Christensen, Inge T; Jørgensen, Flemming S

    2004-01-01

    in the gene coding for Pf-DHFR. Furthermore, we wanted to study the potential use of homology models in general and of Pf-DHFR in particular in predicting antigenic malarial surface epitopes. METHODS: A homology model of Pf-DHFR domain was employed to define an epitope for the development of site...

  19. Homologous Recombination as a Replication Fork Escort: Fork-Protection and Recovery

    Directory of Open Access Journals (Sweden)

    Audrey Costes

    2012-12-01

    Full Text Available Homologous recombination is a universal mechanism that allows DNA repair and ensures the efficiency of DNA replication. The substrate initiating the process of homologous recombination is a single-stranded DNA that promotes a strand exchange reaction resulting in a genetic exchange that promotes genetic diversity and DNA repair. The molecular mechanisms by which homologous recombination repairs a double-strand break have been extensively studied and are now well characterized. However, the mechanisms by which homologous recombination contribute to DNA replication in eukaryotes remains poorly understood. Studies in bacteria have identified multiple roles for the machinery of homologous recombination at replication forks. Here, we review our understanding of the molecular pathways involving the homologous recombination machinery to support the robustness of DNA replication. In addition to its role in fork-recovery and in rebuilding a functional replication fork apparatus, homologous recombination may also act as a fork-protection mechanism. We discuss that some of the fork-escort functions of homologous recombination might be achieved by loading of the recombination machinery at inactivated forks without a need for a strand exchange step; as well as the consequence of such a model for the stability of eukaryotic genomes.

  20. Density parameter estimation for finding clusters of homologous proteins-tracing actinobacterial pathogenicity lifestyles

    DEFF Research Database (Denmark)

    Röttger, Richard; Kalaghatgi, Prabhav; Sun, Peng

    2013-01-01

    Homology detection is a long-standing challenge in computational biology. To tackle this problem, typically all-versus-all BLAST results are coupled with data partitioning approaches resulting in clusters of putative homologous proteins. One of the main problems, however, has been widely neglecte...

  1. Split dose recovery studies using homologous recombination deficient gene knockout chicken B lymphocyte cells

    International Nuclear Information System (INIS)

    Rao, B.S.S.; Tano, Kaori; Utsumi, Hiroshi; Takeda, Shunichi

    2007-01-01

    To understand the role of proteins involved in double strand breaks (DSB) repair modulating sublethal damage (SLD) recovery, chicken B lymphoma (DT 40) cell lines either proficient or deficient in RAD52, XRCC2, XRCC3, RAD51C and RAD51D were subjected to fractionated irradiation and their survival curves charted. Survival curves of both WT DT40 and RAD52 -/- cells had a big shoulder while all the other cells exhibited small shoulders. However, at the higher doses of radiation, RAD51C -/- cells displayed hypersensitivity comparable to the data obtained for the homologous recombination deficient RAD54 -/- cells. Repair of SLD was measured as an increase in survival after a split dose irradiation with an interval of incubation between the radiation doses. All the cell lines (parental DT40 and genetic knockout cell lines viz., RAD52 -/- , XRCC2 -/- XRCC3 -/- RAD51C -/- and RAD51D -/- ) used in this study demonstrated a typical split-dose recovery capacity with a specific peak, which varied depending on the cell type. The maximum survival of WT DT40 and RAD52 -/- was reached at about 1-2 hours after the first dose of radiation and then decreased to a minimum thereafter (5 h). The increase in the survival peaked once again by about 8 hours. The survival trends observed in XRCC2 -/- , XRCC3 -/- , RAD51C -/- and RAD51D -/- knockout cells were also similar, except for the difference in the initial delay of a peak survival for RAD51D -/- and lower survival ratios. The second phase of increase in the survival in these cell lines was much slower in XRCC2 -/- , XRCC3 -/- , RAD51C -/- nd RAD51D -/- and further delayed when compared with that of RAD52 -/- and parental DT40 cells suggesting a dependence on their cell cycle kinetics. This study demonstrates that the participation of RAD52, XRCC2, XRCC3, RAD51C and RAD51D in the DSB repair via homologous recombination is of less importance in comparison to RAD54, as RAD54 deficient cells demonstrated complete absence of SLD recovery

  2. Radio-sensitization of WRN helicase deficient cancer cells by targeting homologous recombination pathway

    International Nuclear Information System (INIS)

    Gupta, Pooja; Saha, Bhaskar; Patro, Birija Sankar; Chattopadhyay, Subrata

    2016-01-01

    Ionizing radiation (IR) induced DNA double-strand breaks (DSBs) are primarily repaired by non-homologous end joining (NHEJ). However, it is well established that a subset DSBs which are accumulated in IR-induced G2 phase are dependent on homologous recombination (HR). DNA repair deficient tumor cells have been shown to accumulate high levels of DNA damage. Consequently, these cells become hyperdependent on DNA damage response pathways, including the CHK1-kinase-mediated HR-repair. These observations suggest that DNA repair deficient tumors should exhibit increased radio-sensitivity under HR inhibition. Genetic defects leading to functional loss of werner (WRN) protein is associated with genomic instability and increased cancer incidence. WRN function is known to be abrogated in several human cancer cells due to hypermethylation of CpGisland-promoter and transcriptional silencing of WRN gene. In the current investigation, using isogenic pairs of cell lines differing only in the WRN function, we showed that WRN-deficient cell lines were hyper-radiosensitive to CHK1 pharmacologic inhibition. Here, we found that unrepaired DSB was drastically increased in WRN-deficient cells vis-à-vis WRN-proficient cells in response to IR and CHK1 inhibitor (CHK1i). Our results revealed a marginal role of NHEJ pathway accountable for the radio-sensitivity of WRN-deficient cells. Interestingly, silencing CTIP, a HR protein required for RAD51 loading, significantly abrogated the CHK1i-mediated radiosensitivity in WRN-deficient cells. Silencing of WRN or CTIP individually led to no significant difference in the extent of DNA end resection, as required during HR pathway. Imperatively, our results revealed that WRN and CTIP together play a complementary role in executing DNA end resection during HR-mediated repair of IR induced DSBs. Altogether, our data indicated that inhibition of IR-induced HR pathway at RAD51 loading, but not at DSB end resection, make the WRN-deficient cancer cells

  3. Failure of homologous synapsis and sex-specific reproduction problems

    Directory of Open Access Journals (Sweden)

    Hiroki eKurahashi

    2012-06-01

    Full Text Available The prophase of meiosis I ensures the correct segregation of chromosomes to each daughter cell. This includes the pairing, synapsis and recombination of homologous chromosomes. A subset of chromosomal abnormalities, including translocation and inversion, disturbs these processes, resulting in the failure to complete synapsis. This activates the meiotic pachytene checkpoint, and the gametes are fated to undergo cell cycle arrest and subsequent apoptosis. Spermatogenic cells appear to be more vulnerable to the pachytene checkpoint, and male carriers of chromosomal abnormalities are more susceptible to infertility. In contrast, oocytes tend to bypass the checkpoint and instead generate other problems, such as chromosome imbalance that often leads to recurrent pregnancy loss in female carriers. Recent advances in genetic manipulation technologies have increased our knowledge about the pachytene checkpoint and surveillance systems that detect chromosomal synapsis. This review focuses on the consequences of synapsis failure in humans and provides an overview of the mechanisms involved. We also discuss the sexual dimorphism of the involved pathways that leads to the differences in reproductive outcomes between males and females.

  4. Concerning the dynamic instability of actin homolog ParM

    International Nuclear Information System (INIS)

    Popp, David; Yamamoto, Akihiro; Iwasa, Mitsusada; Narita, Akihiro; Maeda, Kayo; Maeda, Yuichiro

    2007-01-01

    Using in vitro TIRF- and electron-microscopy, we reinvestigated the dynamics of native ParM, a prokaryotic DNA segregation protein and actin homolog. In contrast to a previous study, which used a cysteine ParM mutant, we find that the polymerization process of wild type ATP-ParM filaments consists of a polymerization phase and a subsequent steady state phase, which is dynamically unstable, like that of microtubules. We find that the apparent bidirectional polymerization of ParM, is not due to the intrinsic nature of this filament, but results from ParM forming randomly oriented bundles in the presence of crowding agents. Our results imply, that in the bacterium, ParM filaments spontaneously form bipolar bundles. Due to their intrinsic dynamic instability, ParM bundles can efficiently 'search' the cytoplasmic lumen for DNA, bind it equally well at the bipolar ends and segregate it approximately symmetrically, by the insertion of ParM subunits at either end

  5. Homologous radioimmunoassay for human epidermal growth factor (urogastrone)

    International Nuclear Information System (INIS)

    Dailey, G.E.; Kraus, J.W.; Orth, D.N.

    1978-01-01

    Epidermal growth factor (EGF), a polypeptide hormone originally discovered in the mouse submaxillary gland, stimulates growth in a variety of tissues in several species. This hormone has recently been identified in human urine. A homologous RIA for human EGF (RIA-hEGF) has been developed. In general, levels were similar to those recently reported using a heterologous RIA system. Twenty-four-hour urinary excretion of RIA-hEGF by normal adult males and females was 63.0 +- 3.0 and 52.0 +- 3.5 (mean +- SE) μg/total vol, or 29.7 +- 1.1 and 39.8 +- 1.7 μg/g creatinine, respectively. Excretion by females taking oral contraceptives was significantly greater (60.1 +- 2.7 μg/g creatinine; P 0.05). Several of those with very low values had histories of alcohol abuse. Excretion by patients with Cushing's syndrome was normal. Patients with psoriasis or recovering from major burns excreted both abnormally high and abnormally low levels of RIA-hEGF, with no obvious correlation to their clinical condition. There was no apparent diurnal or postprandial variation in urinary RIA-hEGF excretion by normal subjects. An excellent linear correlation was observed between RIA-hEGF and creatinine concentrations in each urine sample for each subject, suggesting that RIA-hEGF concentration in a random urine sample provides a valid index of 24-h RIA-hEGF excretion

  6. A persistent homology approach to collective behavior in insect swarms

    Science.gov (United States)

    Sinhuber, Michael; Ouellette, Nicholas T.

    Various animals from birds and fish to insects tend to form aggregates, displaying self-organized collective swarming behavior. Due to their frequent occurrence in nature and their implications for engineered, collective systems, these systems have been investigated and modeled thoroughly for decades. Common approaches range from modeling them with coupled differential equations on the individual level up to continuum approaches. We present an alternative, topology-based approach for describing swarming behavior at the macroscale rather than the microscale. We study laboratory swarms of Chironomus riparius, a flying, non-biting midge. To obtain the time-resolved three-dimensional trajectories of individual insects, we use a multi-camera stereoimaging and particle-tracking setup. To investigate the swarming behavior in a topological sense, we employ a persistent homology approach to identify persisting structures and features in the insect swarm that elude a direct, ensemble-averaging approach. We are able to identify features of sub-clusters in the swarm that show behavior distinct from that of the remaining swarm members. The coexistence of sub-swarms with different features resembles some non-biological systems such as active colloids or even thermodynamic systems.

  7. A somatic origin of homologous Robertsonian translocations and isochromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, W.P.; Bernasconi, F.; Schinzel, A.A. (Univ. of Zurich (Switzerland)); Basaran, S.; Yueksel-Apak, M. (Univ. of Istanbul (Turkey)); Neri, G. (Universita Cattolica, Rome (Italy)); Serville, F. (Hopital d' Enfants Pellegrin, Bordeaux (France)); Balicek, P.; Haluza, R. (Univ. Hospital of Hradeck Kralove, Hradec Kralove (Czech Republic)); Farah, L.M.S. (Escuola Paulista de Medicina, Sao Paulo (Brazil)) (and others)

    1994-02-01

    One t(14q 14q), three t(15q 15q), two t(21q21q), and two t(22q22q) nonmosaic, apparently balanced, de novo Robertsonian translocation cases were investigated with polymorphic markers to establish the origin of the translocated chromosomes. Four cases had results indicative of an isochromosome: one t(14q14q) case with mild mental retardation and maternal uniparental disomy (UPD) for chromosome 14, one t(15q15q) case with the Prader-Willi syndrome and UPD(15), a phenotypically normal carrier of t(22q22q) with maternal UPD(22), and a phenotypically normal t(21q21q) case of paternal UPD(21). All UPD cases showed complete homozygosity throughout the involved chromosome, which is supportive of a postmeiotic origin. In the remaining four cases, maternal and paternal inheritance of the involved chromosome was found, which unambiguously implies a somatic origin. One t(15q15q) female had a child with a ring chromosome 15, which was also of probable postmeiotic origin as recombination between grandparental haplotypes had occurred prior to ring formation. UPD might be expected to result from de novo Robertsonian translocations of meiotic origin; however, all de novo homologous translocation cases, so far reported, with UPD of chromosomes 14, 15, 21, or 22 have been isochromosomes. These data provide the first direct evidence that nonmosaic Robertsonian translocations, as well as isochromosomes, are commonly the result of a mitotic exchange. 75 refs., 1 fig., 4 tabs.

  8. Dilogarithm identities in conformal field theory and group homology

    International Nuclear Information System (INIS)

    Dupont, J.L.

    1994-01-01

    Recently, Rogers' dilogarithm identities have attracted much attention in the setting of conformal field theory as well as lattice model calculations. One of the connecting threads is an identity of Richmond-Szekeres that appeared in the computation of central charges in conformal field theory. We show that the Richmond-Szekeres identity and its extension by Kirillov-Reshetikhin (equivalent to an identity found earlier by Lewin) can be interpreted as a lift of a generator of the third integral homology of a finite cyclic subgroup sitting inside the projective special linear group of all 2x2 real matrices viewed as a discrete group. This connection allows us to clarify a few of the assertions and conjectures stated in the work of Nahm-Recknagel-Terhoven concerning the role of algebraic K-theory and Thurston's program on hyperbolic 3-manifolds. Specifically, it is not related to hyperbolic 3-manifolds as suggested but is more appropriately related to the group manifold of the universal covering group of the projective special linear group of all 2x2 real matrices viewed as a topological group. This also resolves the weaker version of the conjecture as formulated by Kirillov. We end with a summary of a number of open conjectures on the mathematical side. (orig.)

  9. Predictive factors for homologous transfusion during paediatric scoliosis surgery.

    Science.gov (United States)

    Dupuis, Claire; Michelet, Daphné; Hilly, Julie; Diallo, Thierno; Vidal, Christophe; Delivet, Honorine; Nivoche, Yves; Mazda, Keyvan; Dahmani, Souhayl

    2015-12-01

    Blood saving strategies during paediatric spinal surgery often include recombinant erythropoietin (rEPO) and antifibrinolytic therapy (AFT). The goal of this study was to investigate additional preventive factors involved in the risk of blood transfusion. This prospective study was designed with the aim of identifying factors associated with the perioperative (defined as the intraoperative and the first postoperative day) probability of homologous red cell transfusion during scoliosis surgery in children operated during a one year period in our institution. The predictors analysed were: age, weight less than the 3rd percentile (W 255 minutes. ROC analysis for the latter model found an area under the curve of 0.9 (95% confidence interval: 0.8-0.97). The accuracy of the model was 92.3% (97.4% for non-transfusion and 69.2% for transfusion). Multivariate sensitivity analysis excluding patients with no preoperative administration of EPO found similar results. The current results indicate that optimising nutritional status might prevent allogenic blood transfusion and requires further investigation. Copyright © 2015 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.

  10. Homology among tet determinants in conjugative elements of streptococci

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.D.; Hazum, S.; Guild, W.R.

    1981-10-01

    A mutation to tetracycline sensitivity in a resistant strain of Streptococcus pneumoniae was shown by several criteria to be due to a point mutation in the conjugative o(cat-tet) element found in the chromosomes of strains derived from BM6001, a clinical strain resistant to tetracycline and chloramphenicol. Strains carrying the mutation were transformed back to tetracycline resistance with the high efficiency of a point marker by donor deoxyribonucleic acids from its ancestral strain and from nine other clinical isolates of pneumococcus and by deoxyribonucleic acids from Group D Streptococcus faecalis and Group B Streptococcus agalactiae strains that also carry conjugative tet elements in their chromosomes. It was not transformed to resistance by tet plasmid deoxyribonucleic acids from either gram-negative or gram-positive species, except for one that carried transposon TN916, the conjugative tet element present in the chromosomes of some S. faecalis strains. The results showed that the tet determinants in conjugative elements of several streptococcal species share a high degree of deoxyribonucleic acid sequence homology and suggested that they differ from other tet genes.

  11. Surface structure evolution in a homologous series of ionic liquids.

    Science.gov (United States)

    Haddad, Julia; Pontoni, Diego; Murphy, Bridget M; Festersen, Sven; Runge, Benjamin; Magnussen, Olaf M; Steinrück, Hans-Georg; Reichert, Harald; Ocko, Benjamin M; Deutsch, Moshe

    2018-02-06

    Interfaces of room temperature ionic liquids (RTILs) are important for both applications and basic science and are therefore intensely studied. However, the evolution of their interface structure with the cation's alkyl chain length [Formula: see text] from Coulomb to van der Waals interaction domination has not yet been studied for even a single broad homologous RTIL series. We present here such a study of the liquid-air interface for [Formula: see text], using angstrom-resolution X-ray methods. For [Formula: see text], a typical "simple liquid" monotonic surface-normal electron density profile [Formula: see text] is obtained, like those of water and organic solvents. For [Formula: see text], increasingly more pronounced nanoscale self-segregation of the molecules' charged moieties and apolar chains yields surface layering with alternating regions of headgroups and chains. The layering decays into the bulk over a few, to a few tens, of nanometers. The layering periods and decay lengths, their linear [Formula: see text] dependence, and slopes are discussed within two models, one with partial-chain interdigitation and the other with liquid-like chains. No surface-parallel long-range order is found within the surface layer. For [Formula: see text], a different surface phase is observed above melting. Our results also impact general liquid-phase issues like supramolecular self-aggregation and bulk-surface structure relations.

  12. Creating Virtual Exhibitions for Educational and Cultural Development

    Directory of Open Access Journals (Sweden)

    Gabriela DUMITRESCU

    2014-01-01

    Full Text Available The paper presents different tools and mechanisms to implement a virtual exhibition in different cultural areas, such as museums and libraries. Quality characteristics of virtual exhibitions are identified and described. The possibility to create native mobile applications for virtual exhibitions presentation is analyzed. The functional flow of creating a virtual exhibition is presented and discussed. The Seals - History Treasure exhibition is presented and significant historical documents are revealed.

  13. Divergent Roles of RPA Homologs of the Model Archaeon Halobacterium salinarum in Survival of DNA Damage.

    Science.gov (United States)

    Evans, Jessica J; Gygli, Patrick E; McCaskill, Julienne; DeVeaux, Linda C

    2018-04-20

    The haloarchaea are unusual in possessing genes for multiple homologs to the ubiquitous single-stranded DNA binding protein (SSB or replication protein A, RPA) found in all three domains of life. Halobacterium salinarum contains five homologs: two are eukaryotic in organization, two are prokaryotic and are encoded on the minichromosomes, and one is uniquely euryarchaeal. Radiation-resistant mutants previously isolated show upregulation of one of the eukaryotic-type RPA genes. Here, we have created deletions in the five RPA operons. These deletion mutants were exposed to DNA-damaging conditions: ionizing radiation, UV radiation, and mitomycin C. Deletion of the euryarchaeal homolog, although not lethal as in Haloferax volcanii , causes severe sensitivity to all of these agents. Deletion of the other RPA/SSB homologs imparts a variable sensitivity to these DNA-damaging agents, suggesting that the different RPA homologs have specialized roles depending on the type of genomic insult encountered.

  14. PCR artifact in testing for homologous recombination in genomic editing in zebrafish.

    Directory of Open Access Journals (Sweden)

    Minho Won

    Full Text Available We report a PCR-induced artifact in testing for homologous recombination in zebrafish. We attempted to replace the lnx2a gene with a donor cassette, mediated by a TALEN induced double stranded cut. The donor construct was flanked with homology arms of about 1 kb at the 5' and 3' ends. Injected embryos (G0 were raised and outcrossed to wild type fish. A fraction of the progeny appeared to have undergone the desired homologous recombination, as tested by PCR using primer pairs extending from genomic DNA outside the homology region to a site within the donor cassette. However, Southern blots revealed that no recombination had taken place. We conclude that recombination happened during PCR in vitro between the donor integrated elsewhere in the genome and the lnx2a locus. We conclude that PCR alone may be insufficient to verify homologous recombination in genome editing experiments in zebrafish.

  15. A sensitive short read homology search tool for paired-end read sequencing data.

    Science.gov (United States)

    Techa-Angkoon, Prapaporn; Sun, Yanni; Lei, Jikai

    2017-10-16

    Homology search is still a significant step in functional analysis for genomic data. Profile Hidden Markov Model-based homology search has been widely used in protein domain analysis in many different species. In particular, with the fast accumulation of transcriptomic data of non-model species and metagenomic data, profile homology search is widely adopted in integrated pipelines for functional analysis. While the state-of-the-art tool HMMER has achieved high sensitivity and accuracy in domain annotation, the sensitivity of HMMER on short reads declines rapidly. The low sensitivity on short read homology search can lead to inaccurate domain composition and abundance computation. Our experimental results showed that half of the reads were missed by HMMER for a RNA-Seq dataset. Thus, there is a need for better methods to improve the homology search performance for short reads. We introduce a profile homology search tool named Short-Pair that is designed for short paired-end reads. By using an approximate Bayesian approach employing distribution of fragment lengths and alignment scores, Short-Pair can retrieve the missing end and determine true domains. In particular, Short-Pair increases the accuracy in aligning short reads that are part of remote homologs. We applied Short-Pair to a RNA-Seq dataset and a metagenomic dataset and quantified its sensitivity and accuracy on homology search. The experimental results show that Short-Pair can achieve better overall performance than the state-of-the-art methodology of profile homology search. Short-Pair is best used for next-generation sequencing (NGS) data that lack reference genomes. It provides a complementary paired-end read homology search tool to HMMER. The source code is freely available at https://sourceforge.net/projects/short-pair/ .

  16. The Fanconi anemia group A protein modulates homologous repair of DNA double-strand breaks in mammalian cells.

    Science.gov (United States)

    Yang, Yun-Gui; Herceg, Zdenko; Nakanishi, Koji; Demuth, Ilja; Piccoli, Colette; Michelon, Jocelyne; Hildebrand, Gabriele; Jasin, Maria; Digweed, Martin; Wang, Zhao-Qi

    2005-10-01

    Fanconi anemia (FA) cells exhibit hypersensitivity to DNA interstrand cross-links (ICLs) and high levels of chromosome instability. FA gene products have been shown to functionally or physically interact with BRCA1, RAD51 and the MRE11/RAD50/NBS1 complex, suggesting that the FA complex may be involved in the repair of DNA double-strand breaks (DSBs). Here, we have investigated specifically the function of the FA group A protein (FANCA) in the repair of DSBs in mammalian cells. We show that the targeted deletion of Fanca exons 37-39 generates a null for Fanca in mice and abolishes ubiquitination of Fancd2, the downstream effector of the FA complex. Cells lacking Fanca exhibit increased chromosomal aberrations and attenuated accumulation of Brca1 and Rad51 foci in response to DNA damage. The absence of Fanca greatly reduces gene-targeting efficiency in mouse embryonic stem (ES) cells and compromises the survival of fibroblast cells in response to ICL agent treatment. Fanca-null cells exhibit compromised homology-directed repair (HDR) of DSBs, particularly affecting the single-strand annealing pathway. These data identify the Fanca protein as an integral component in the early step of HDR of DSBs and thereby minimizing the genomic instability.

  17. Hepatic receptors for homologous growth hormone in the eel

    International Nuclear Information System (INIS)

    Hirano, T.

    1991-01-01

    The specific binding of 125I-labeled eel growth hormone (eGH) to liver membranes of the eel was examined. The specific binding to the 10,000g pellet was greater than that to the 600g pellet. The specific binding was linear up to about 100 mg fresh tissue, and was saturable with increasing amounts of membrane. The specific binding was pH-, temperature-, and time-dependent, with the optimum pH at 7.4, and greater specific binding was obtained at 15 and 25 degrees than at 35 degrees. Scatchard analysis of liver binding gave an association constant of 1.1 x 10(9) M-1 and a capacity of 105 fmol/mg protein. The receptor preparation was highly specific for GHs. Natural and recombinant eel GHs as well as recombinant salmon GH competed equally with 125I-eGH for the receptor sites of the 10,000g liver membrane. Ovine GH was more potent in displacing the labeled eGH than the homologous eel hormone. Tilapia GH and ovine prolactin (PRL) were needed in greater amounts (40 times) than eGH to displace the labeled eGH. Salmon and tilapia PRLs were still less potent (500 times) than eGH. There was no displacement with eel PRL. No significant change in the specific binding was seen 1 week after hypophysectomy, whereas injection of eGH into the hypophysectomized eel caused a significant reduction after 24 hr. The binding to the membrane fractions from gills, kidney, muscle, intestine, and brain was low and exclusively nonspecific, indicating the presence of specific GH receptors predominantly in the liver

  18. Original Mycobacterial Sin, a consequence of highly homologous antigens?

    Science.gov (United States)

    Jenkins, A O; Michel, A; Rutten, V

    2017-05-01

    The role of antigens shared between Mycobacteria in in-vivo cross-reactive immune responses in host animals, have been reported to be responsible for reduced BCG vaccination efficacy as well reduced specificity of routine immunological diagnostic tests. This presents with significant disease control challenges in humans and animals. The present review highlights the results of previous studies on the effect of pre-sensitization to environmental mycobacteria on either pathogenic mycobacteria and/or M. bovis BCG, in experimental animals. It also takes an in-depth view into assessing the genetic similarities and relationships between atypical mycobacteria and Mycobacterium tuberculosis complex (MTBC) and how they might explain the immunological imprint of environmental mycobacteria in directing the hosts' immune response upon subsequent exposure to other classes of mycobacteria. The outcome of this review suggests that genetic closeness between particular atypical mycobacteria and MTBC usually indicate a higher level of homology for certain shared protective antigens. This ultimately results in a higher level of cross reactive immune responses as compared with other atypical mycobacteria that are further away genetically. This would explain the different effects of environmental mycobacteria on MTBC that have been reported in the different studies. In other words the direction of the host immune system in response to exposure to MTBC would depend on the type of environmental mycobacteria that was encountered in the initial exposure. We also explain these mycobacterial interactions in the context of the phenomenon of "Original Mycobacterial Sin". The effects of these inevitable mycobacterial interactions on field diagnosis and control by vaccination and how to circumvent them are discussed. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Structural analysis of the Csk homologous kinase CHK

    International Nuclear Information System (INIS)

    Mulhern, T.; Chong, Y.-P.; Cheng, H.-C.

    2003-01-01

    Full text: CHK (Csk homologous kinase) is an intracellular protein tyrosine kinase, which is highly expressed in the haematopoietic system and the brain. The in vivo role of CHK is to specifically phosphorylate and deactivate the Src family of protein tyrosine kinases. The members of the Src family: Src, Blk, Fyn, Fgr, Hck, Lck, Lyn, Yes and Yrk are major players in numerous cell signalling pathways and exquisitely tuned control of Src family activity is fundamental to many processes in normal cells (reviewed in Lowell and Soriano, 1996). For example, the Src family kinase Fyn is highly expressed in the brain and its activity is vital for memory and learning. In the haematopoietic system, the Src family kinase Hck controls cytoskeletal reorganization, cell motility and immunologic activation. While the Csk family enzymes are closely related to the Src proteins (∼37% identity), the x-ray crystal structures of Src (Xu et al., 1997) and Csk (Ogawa et al., 2002) do display several important differences. Unlike Src, the Csk the SH2 and SH3 domains do not bind intramolecular ligands and they adopt a strikingly different disposition to that observed in Src. Another interesting feature is that the linkers between the SH3 and SH2 domains and between the SH2 and kinase domains, are in intimate contact with the N-lobe of kinase and both appear to play important roles in regulation of the kinase activity. However, the structural and functional basis of how this can be altered is still unclear. We describe the results of biochemical analyses of CHK mediated deactivation of Hck, which suggest that in addition to direct tail-phosphorylation, protein-protein interactions are important. We also describe heteronuclear NMR studies of the structure and ligand binding properties of the CHK SH2 and SH3 domains with a particular emphasis on the transmission of regulatory signals from the ligand binding sites to the interdomain linkers

  20. A content-oriented model for science exhibit engineering

    DEFF Research Database (Denmark)

    Achiam, Marianne

    2013-01-01

    Recently, science museums have begun to review their educational purposes and redesign their pedagogies. At the most basic level, this entails accounting for the performance of individual exhibits, and indeed, in some cases, research indicates shortcomings in exhibit design: While often successful......: as a means to operationalize the link between exhibit features and visitor activities; and as a template to transform scientists’ practices in the research context into visitors’ activities in the exhibit context. The resulting model of science exhibit engineering is presented and exemplified, and its...... implications for science exhibit design are discussed at three levels: the design product, the design process, and the design methodology....

  1. Studies of flerovium and element 115 homologs with macrocyclic extractants

    Science.gov (United States)

    Despotopulos, John Dustin

    Study of the chemistry of the heaviest elements, Z ? 104, poses a unique challenge due to their low production cross-sections and short half-lives. Chemistry also must be studied on the one-atom-at-a-time scale, requiring automated, fast, and very efficient chemical schemes. Recent studies of the chemical behavior of copernicium (Cn, element 112) and flerovium (Fl, element 114) together with the discovery of isotopes of these elements with half-lives suitable for chemical studies have spurred a renewed interest in the development of rapid systems designed to study the chemical properties of elements with Z ≥ 114. This dissertation explores both extraction chromatography and solvent extraction as methods for development of a rapid chemical separation scheme for the homologs of flerovium (Pb, Sn, Hg) and element 115 (Bi, Sb), with the goal of developing a chemical scheme that, in the future, can be applied to on-line chemistry of both Fl and element 115. Macrocyclic extractants, specifically crown ethers and their derivatives, were chosen for these studies. Carrier-free radionuclides, used in these studies, of the homologs of Fl and element 115 were obtained by proton activation of high purity metal foils at the Lawrence Livermore National Laboratory (LLNL) Center for Accelerator Mass Spectrometry (CAMS): natIn(p,n)113Sn, natSn(p,n)124Sb, and Au(p,n)197m,gHg. The carrier-free activity was separated from the foils by novel separation schemes based on ion exchange and extraction chromatography techniques. Carrier-free Pb and Bi isotopes were obtained from development of a novel generator based on cation exchange chromatography using the 232U parent to generate 212Pb and 212Bi. Crown ethers show high selectivity for metal ions based on their size compared to the negatively charged cavity of the ether. Extraction by crown ethers occur based on electrostatic ion-dipole interactions between the negatively charged ring atoms (oxygen, sulfur, etc.) and the positively

  2. [Sequence analysis of LEAFY homologous gene from Dendrobium moniliforme and application for identification of medicinal Dendrobium].

    Science.gov (United States)

    Xing, Wen-Rui; Hou, Bei-Wei; Guan, Jing-Jiao; Luo, Jing; Ding, Xiao-Yu

    2013-04-01

    The LEAFY (LFY) homologous gene of Dendrobium moniliforme (L.) Sw. was cloned by new primers which were designed based on the conservative region of known sequences of orchid LEAFY gene. Partial LFY homologous gene was cloned by common PCR, then we got the complete LFY homologous gene Den LFY by Tail-PCR. The complete sequence of DenLFY gene was 3 575 bp which contained three exons and two introns. Using BLAST method, comparison analysis among the exon of LFY homologous gene indicted that the DenLFY gene had high identity with orchids LFY homologous, including the related fragment of PhalLFY (84%) in Phalaenopsis hybrid cultivar, LFY homologous gene in Oncidium (90%) and in other orchid (over 80%). Using MP analysis, Dendrobium is found to be the sister to Oncidium and Phalaenopsis. Homologous analysis demonstrated that the C-terminal amino acids were highly conserved. When the exons and introns were separately considered, exons and the sequence of amino acid were good markers for the function research of DenLFY gene. The second intron can be used in authentication research of Dendrobium based on the length polymorphism between Dendrobium moniliforme and Dendrobium officinale.

  3. K-theory and periodic cyclic homology of some noncompact quantum algebras

    International Nuclear Information System (INIS)

    Do Ngoc Diep; Kuku, Aderemi O.

    2003-07-01

    We prove in this paper that the periodic cyclic homology of the quantized algebras of functions on coadjoint orbits of connected and simply connected Lie group, are isomorphic to the periodic cyclic homology of the quantized algebras of functions on coadjoint orbits of compact maximal subgroups, without localization. Some noncompact quantum groups and algebras were constructed and their irreducible representations were classified in recent works of Do Ngoc Diep and Nguyen Viet Hai [DH1]-[DH2] and Do Due Hanh [DD] by using deformation quantization. In this paper we compute their K-groups, periodic cyclic homology groups and their Chern characters. (author)

  4. 76 FR 68808 - Culturally Significant Objects Imported for Exhibition

    Science.gov (United States)

    2011-11-07

    ... also determine that the exhibition or display of the exhibit objects at the Onassis Cultural Center... Century AD,'' imported from abroad for temporary exhibition within the United States, are of cultural... Cultural Affairs, Department of State. [FR Doc. 2011-28805 Filed 11-4-11; 8:45 am] BILLING CODE 4710-05-P ...

  5. 78 FR 7849 - Culturally Significant Objects Imported for Exhibition

    Science.gov (United States)

    2013-02-04

    ... Century,'' imported from abroad for temporary exhibition within the United States, are of cultural... also determine that the exhibition or display of the exhibit objects at The Yale Center for British Art..., Bureau of Educational and Cultural Affairs, Department of State. [FR Doc. 2013-02401 Filed 2-1-13; 8:45...

  6. A Salamander Tale: Effective Exhibits and Attitude Change

    Science.gov (United States)

    Rollins, Jeffrey; Watson, Sunnie Lee

    2017-01-01

    Little information exists regarding intention behind the design and development of Extension outreach and educational exhibits. An evaluation of response to the exhibit "A Salamander Tale" indicates that the methods used to develop the exhibit resulted in an effective way to present information to an adult audience. Survey questions were…

  7. Cloning and characterization of WRKY gene homologs in Chieh-qua (Benincasa hispida Cogn. var. Chieh-qua How) and their expression in response to fusaric acid treatment.

    Science.gov (United States)

    Mao, Yizhou; Jiang, Biao; Peng, Qingwu; Liu, Wenrui; Lin, Yue; Xie, Dasen; He, Xiaoming; Li, Shaoshan

    2017-05-01

    The WRKY transcription factors play an important role in plant resistance for biotic and abiotic stresses. In the present study, we cloned 10 WRKY gene homologs (CqWRKY) in Chieh-qua (Benincasa hispida Cogn. var. Chieh-qua) using the rapid-amplification of cDNA ends (RACE) or homology-based cloning methods. We characterized the structure of these CqWRKY genes. Phylogenetic analysis of these sequences with cucumber homologs suggested possible structural conservation of these genes among cucurbit crops. We examined the expression levels of these genes in response to fusaric acid (FA) treatment between resistant and susceptible Chieh-qua lines with quantitative real-time PCR. All genes could be upregulated upon FA treatment, but four CqWRKY genes exhibited differential expression between resistant and susceptible lines before and after FA application. CqWRKY31 seemed to be a positive regulator while CqWRKY1, CqWRKY23 and CqWRKY53 were negative regulators of fusaric resistance. This is the first report of characterization of WRKY family genes in Chieh-qua. The results may also be useful in breeding Chieh-qua for Fusarium wilt resistance.

  8. Synergistic interactions between RAD5, RAD16, and RAD54, three partially homologous yeast DNA repair genes each in a different repair pathway

    International Nuclear Information System (INIS)

    Glassner, B.J.; Mortimer, R.K.

    1994-01-01

    Considerable homology has recently been noted between the proteins encoded by the RAD5, RAD16 and RAD54 genes of Saccharomyces cerevisiae. These genes are members of the RAD6, RAD3 and RAD50 epistasis groups, respectively, which correspond to the three major DNA repair pathways in yeast. These proteins also share homology with other eucaryotic proteins, including those encoded by SNF2 and MO1 of yeast, brahma and lodestar of Drosophila and the human ERCC6 gene. The homology shares features with known helicases, suggesting a newly identified helicase subfamily. We have constructed a series of congenic single-, double- and triple-deletion mutants involving RAD5, RAD16 and RAD54 to examine the interactions between these genes. Each deletion mutation alone has only a moderate effect on survival after exposure to UV radiation. Each pairwise-double mutant exhibits marked synergism. The triple-deletion mutant displays further synergism. These results confirm the assignment of the RAD54 gene to the RAD50 epistasis group and suggest that the RAD16 gene plays a larger role in DNA repair after exposure to UV radiation than has been suggested previously. Additionally, the proteins encoded by RAD5, RAD16, and RAD54 may compete for the same substrate after damage induced by UV radiation, possibly at an early step in their respective pathways. 49 refs., 6 figs., 2 tabs

  9. Homologous recombination in Arabidopsis seeds along the track of energetic carbon ions

    International Nuclear Information System (INIS)

    Wang Ting; Li Fanghua; Liu Qingfang; Bian Po; Wang Jufang; Wu Yuejin; Wu Lijun; Li Wenjian

    2012-01-01

    Heavy ion irradiation has been used as radiotherapy of deep-seated tumors, and is also an inevitable health concern for astronauts in space mission. Unlike photons such as X-rays and γ-rays, a high linear energy transfer (LET) heavy ion has a varying energy distribution along its track. Therefore, it is important to determine the correlation of biological effects with the Bragg curve energy distribution of heavy ions. In this study, a continuous biological tissue equivalent was constructed using a layered cylinder of Arabidopsis seeds, which was irradiated with carbon ions of 87.5 MeV/nucleon. The position of energy loss peak in the seed pool was determined with CR-39 track detectors. The mutagenic effect in vivo along the path of carbon ions was investigated with the seeds in each layer as an assay unit, which corresponded to a given position in physical Bragg curve. Homologous recombination frequency (HRF), expression level of AtRAD54 gene, germination rate of seeds, and survival rate of young seedlings were used as checking endpoints, respectively. Our results showed that Arabidopsis S0 and S1 plants exhibited significant increases in HRF compared to their controls, and the expression level of AtRAD54 gene in S0 plants was significantly up-regulated. The depth-biological effect curves for HRF and the expression of AtRAD54 gene were not consistent with the physical Bragg curve. Differently, the depth-biological effect curves for the developmental endpoints matched generally with the physical Bragg curve. The results suggested a different response pattern of various types of biological events to heavy ion irradiation. It is also interesting that except for HRF in S0 plants, the depth-biological effect curves for each biological endpoint were similar for 5 Gy and 30 Gy of carbon irradiation.

  10. Homologous recombination in Arabidopsis seeds along the track of energetic carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ting [University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026 (China); Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Li Fanghua [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Liu Qingfang [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Bian Po, E-mail: bianpo@ipp.ac.cn [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Wang Jufang [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Wu Yuejin; Wu Lijun [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Li Wenjian [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China)

    2012-09-01

    Heavy ion irradiation has been used as radiotherapy of deep-seated tumors, and is also an inevitable health concern for astronauts in space mission. Unlike photons such as X-rays and {gamma}-rays, a high linear energy transfer (LET) heavy ion has a varying energy distribution along its track. Therefore, it is important to determine the correlation of biological effects with the Bragg curve energy distribution of heavy ions. In this study, a continuous biological tissue equivalent was constructed using a layered cylinder of Arabidopsis seeds, which was irradiated with carbon ions of 87.5 MeV/nucleon. The position of energy loss peak in the seed pool was determined with CR-39 track detectors. The mutagenic effect in vivo along the path of carbon ions was investigated with the seeds in each layer as an assay unit, which corresponded to a given position in physical Bragg curve. Homologous recombination frequency (HRF), expression level of AtRAD54 gene, germination rate of seeds, and survival rate of young seedlings were used as checking endpoints, respectively. Our results showed that Arabidopsis S0 and S1 plants exhibited significant increases in HRF compared to their controls, and the expression level of AtRAD54 gene in S0 plants was significantly up-regulated. The depth-biological effect curves for HRF and the expression of AtRAD54 gene were not consistent with the physical Bragg curve. Differently, the depth-biological effect curves for the developmental endpoints matched generally with the physical Bragg curve. The results suggested a different response pattern of various types of biological events to heavy ion irradiation. It is also interesting that except for HRF in S0 plants, the depth-biological effect curves for each biological endpoint were similar for 5 Gy and 30 Gy of carbon irradiation.

  11. Creation of metal-independent hyperthermophilic L-arabinose isomerase by homologous recombination.

    Science.gov (United States)

    Hong, Young-Ho; Lee, Dong-Woo; Pyun, Yu-Ryang; Lee, Sung Haeng

    2011-12-28

    Hyperthermophilic L-arabinose isomerases (AIs) are useful in the commercial production of D-tagatose as a low-calorie bulk sweetener. Their catalysis and thermostability are highly dependent on metals, which is a major drawback in food applications. To study the role of metal ions in the thermostability and catalysis of hyperthermophilic AI, four enzyme chimeras were generated by PCR-based hybridization to replace the variable N- and C-terminal regions of hyperthermophilic Thermotoga maritima AI (TMAI) and thermophilic Geobacillus stearothermophilus AI (GSAI) with those of the homologous mesophilic Bacillus halodurans AI (BHAI). Unlike Mn(2+)-dependent TMAI, the GSAI- and TMAI-based hybrids with the 72 C-terminal residues of BHAI were not metal-dependent for catalytic activity. By contrast, the catalytic activities of the TMAI- and GSAI-based hybrids containing the N-terminus (residues 1-89) of BHAI were significantly enhanced by metals, but their thermostabilities were poor even in the presence of Mn(2+), indicating that the effects of metals on catalysis and thermostability involve different structural regions. Moreover, in contrast to the C-terminal truncate (Δ20 residues) of GSAI, the N-terminal truncate (Δ7 residues) exhibited no activity due to loss of its native structure. The data thus strongly suggest that the metal dependence of the catalysis and thermostability of hyperthermophilic AIs evolved separately to optimize their activity and thermostability at elevated temperatures. This may provide effective target regions for engineering, thereby meeting industrial demands for the production of d-tagatose.

  12. Evolution of Metapostnotum in Flat Wasps (Hymenoptera, Bethylidae: Implications for Homology Assessments in Chrysidoidea.

    Directory of Open Access Journals (Sweden)

    Ricardo Kawada

    Full Text Available Some authors in the past based their conclusions about the limits of the metapostnotum of Chrysidoidea based on the position of the mesophragmo-metaphragmal muscle, rather than aspects of the skeleton and musculature associated with the metapectal-propodeal complex. The latter character system suggests another interpretation of the metapostnotum delimitation. Given this scenario, the main goal of this work is to present a new perspective on the metapostnotum in Chrysidoidea, especially Bethylidae, helping to resolve questions related to the evolution of the metapostnotum. This is based on homologies established by associating of insertion points of ph2-ph3 and ph3-T2 muscles with the delimitation of the respective sclerite the muscles insert into. Our results indicate that, according the position of the metaphragmal muscles, the metapostnotum in Bethylidae is medially expanded in the propodeal disc and has different forms of configuration. Internally, the limits of the metapostnotum can be tracked by the shape of the mesopostnotum, and vice versa. Thus, the anteromedian area of the propodeal disc sensu Evans was reinterpreted in the current study as the metapostnotum. In conjunction with associated structures, we provide evidence to clarify the relationships between the families within Chrysidoidea, although certain families like Embolemidae, Dryinidae and Chrysididae exhibit extreme modifications of the condition found in Aculeata, as observed in Bethylidae. We review the terminology used to describe anatomical features on the metapectal-propodeal complex in Bethylidae in general, and provide a list of recommended terms in accordance with the online Hymenoptera Anatomy Ontology. The morphology of the studied subfamilies are illustrated. Studies that focus on a single structure, across a larger number of taxa, are more insightful and present specific questions that can contribute to broader issues, thus providing a better understanding of the

  13. Overexpression of the homologous lanosterol synthase gene in ganoderic acid biosynthesis in Ganoderma lingzhi.

    Science.gov (United States)

    Zhang, De-Huai; Li, Na; Yu, Xuya; Zhao, Peng; Li, Tao; Xu, Jun-Wei

    2017-02-01

    Ganoderic acids (GAs) in Ganoderma lingzhi exhibit anticancer and antimetastatic activities. GA yields can be potentially improved by manipulating G. lingzhi through genetic engineering. In this study, a putative lanosterol synthase (LS) gene was cloned and overexpressed in G. lingzhi. Results showed that its overexpression (OE) increased the ganoderic acid (GA) content and the accumulation of lanosterol and ergosterol in a submerged G. lingzhi culture. The maximum contents of GA-O, GA-Mk, GA-T, GA-S, GA-Mf, and GA-Me in transgenic strains were 46.6 ± 4.8, 24.3 ± 3.5, 69.8 ± 8.2, 28.9 ± 1.4, 15.4 ± 1.2, and 26.7 ± 3.1 μg/100 mg dry weight, respectively, these values being 6.1-, 2.2-, 3.2-, 4.8-, 2.0-, and 1.9-times higher than those in wild-type strains. In addition, accumulated amounts of lanosterol and ergosterol in transgenic strains were 2.3 and 1.4-fold higher than those in the control strains, respectively. The transcription level of LS was also increased by more than five times in the presence of the G. lingzhi glyceraldehyde-3-phosphate dehydrogenase gene promoter, whereas transcription levels of 3-hydroxy-3-methylglutaryl coenzyme A enzyme and squalene synthase did not change significantly in transgenic strains. This study demonstrated that OE of the homologous LS gene can enhance lanosterol accumulation. A large precursor supply promotes GA biosynthesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Digital Natives: Creating Emergent Exhibitions through Digital Technologies

    DEFF Research Database (Denmark)

    Smith, Rachel Charlotte; Iversen, Ole Sejer; Dindler, Christian

    2011-01-01

    . In this way, digital technology can contribute to the creation of emergent exhibitions in which the exhibition is created in dialogue between audiences and the museum. We present experiences from a current research project, the Digital Natives exhibition, in which digital technology was designed......Digital Technology can support the creation of dialogical spaces in the museum, both playful and reflective, that allow audiences to engage in the ongoing construction and reproduction of cultural heritage creating novel connections between self and others and between past, present and future...... as an integral part of the exhibition to encourage dialogue between audiences and the exhibition materials and thereby investigate how the exhibition emerge as a result of this dialogic co-construction inside the exhibition space. In short, the opportunities offered by digital technologies prompts us to consider...

  15. The tumor suppressor homolog in fission yeast, myh1{sup +}, displays a strong interaction with the checkpoint gene rad1{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Kristina; Warringer, Jonas; Farewell, Anne [Department of Cell and Molecular Biology, Lundberg Laboratory, Goeteborg University, P.O. Box 462, Goeteborg SE-405 30 (Sweden); Park, Han-Oh [Bioneer Corporation, 49-3, Munpyeong-dong, Daedeok-gu, Daejon 306-220 (Korea, Republic of); Hoe, Kwang-Lae; Kim, Dong-Uk [Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yusong, Daejeon (Korea, Republic of); Hayles, Jacqueline [Cell Cycle Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln' s Inn Fields, London WC2A 3PX (United Kingdom); Sunnerhagen, Per [Department of Cell and Molecular Biology, Lundberg Laboratory, Goeteborg University, P.O. Box 462, Goeteborg SE-405 30 (Sweden)], E-mail: per.sunnerhagen@cmb.gu.se

    2008-09-26

    The DNA glycosylase MutY is strongly conserved in evolution, and homologs are found in most eukaryotes and prokaryotes examined. This protein is implicated in repair of oxidative DNA damage, in particular adenine mispaired opposite 7,8-dihydro-8-oxoguanine. Previous investigations in Escherichia coli, fission yeast, and mammalian cells show an association of mutations in MutY homologs with a mutator phenotype and carcinogenesis. Eukaryotic MutY homologs physically associate with several proteins with a role in replication, DNA repair, and checkpoint signaling, specifically the trimeric 9-1-1 complex. In a genetic investigation of the fission yeast MutY homolog, myh1{sup +}, we show that the myh1 mutation confers a moderately increased UV sensitivity alone and in combination with mutations in several DNA repair genes. The myh1 rad1, and to a lesser degree myh1 rad9, double mutants display a synthetic interaction resulting in enhanced sensitivity to DNA damaging agents and hydroxyurea. UV irradiation of myh1 rad1 double mutants results in severe chromosome segregation defects and visible DNA fragmentation, and a failure to activate the checkpoint. Additionally, myh1 rad1 double mutants exhibit morphological defects in the absence of DNA damaging agents. We also found a moderate suppression of the slow growth and UV sensitivity of rhp51 mutants by the myh1 mutation. Our results implicate fission yeast Myh1 in repair of a wider range of DNA damage than previously thought, and functionally link it to the checkpoint pathway.

  16. An Approach for Zika Virus Inhibition Using Homology Structure of the Envelope Protein

    Czech Academy of Sciences Publication Activity Database

    Fernando, S.; Fernando, T.; Štefánik, M.; Eyer, Luděk; Růžek, Daniel

    2016-01-01

    Roč. 58, č. 12 (2016), s. 801-806 ISSN 1073-6085 Institutional support: RVO:60077344 Keywords : Zika virus * homology model * druggability * drug discovery Subject RIV: EE - Microbiology, Virology Impact factor: 1.634, year: 2016

  17. Regulation of homologous recombination repair protein Rad51 by Ku70

    International Nuclear Information System (INIS)

    Du Liqing; Liu Qiang; Wang Yan; Xu Chang; Cao Jia; Fu Yue; Chen Fenghua; Fan Feiyue

    2013-01-01

    Objective: To explore the regulative effect of non-homologous end joining (NHEJ)protein Ku70 on homologous recombination repair protein Rad51, and to investigate the synergistic mechanism of homologous recombination repair in combination with NHEJ. Methods: Observed Rad51 protein expression after transfect Ku70 small interfering RNA or Ku70 plasmid DNA into tumor cells using Western blot. Results: Expression of Rad51 was obviously reduced after pretreated with Ku70 small interfering RNA. And with the increasing expression of Ku70 protein after transfection of Ku70 plasmid DNA PGCsi3.0-hKu70 into tumor cell lines, the Rad51 protein expression was increased. Conclusion: Ku70 protein has regulating effect on gene expression of Rad51, and it might participate in the collaboration between homologous recombination repair and NHEJ. (authors)

  18. Single-cell template strand sequencing by Strand-seq enables the characterization of individual homologs

    NARCIS (Netherlands)

    Sanders, Ashley D; Falconer, Ester; Hills, Mark; Spierings, Diana C J; Lansdorp, Peter M.

    The ability to distinguish between genome sequences of homologous chromosomes in single cells is important for studies of copy-neutral genomic rearrangements (such as inversions and translocations), building chromosome-length haplotypes, refining genome assemblies, mapping sister chromatid exchange

  19. Integration of vectors by homologous recombination in the plant pathogen Glomerella cingulata.

    Science.gov (United States)

    Rikkerink, E H; Solon, S L; Crowhurst, R N; Templeton, M D

    1994-03-01

    An homologous transformation system has been developed for the plant pathogenic fungus Glomerella cingulata (Colletotrichum gloeosporioides). A transformation vector containing the G. cingulata gpdA promoter fused to the hygromycin phosphotransferase gene was constructed. Southern analyses indicated that this vector integrated at single sites in most transformants. A novel method of PCR amplification across the recombination junction point indicated that the integration event occurred by homologous recombination in more than 95% of the transformants. Deletion studies demonstrated that 505 bp (the minimum length of homologous promoter DNA analysed which was still capable of promoter function) was sufficient to target integration events. Homologous integration of the vector resulted in duplication of the gdpA promoter region. When transformants were grown without selective pressure, a high incidence of vector excision by recombination between the duplicated regions was evident. The significance of these recombination characteristics is discussed with reference to the feasibility of performing gene disruption experiments.

  20. CPHmodels-3.0--remote homology modeling using structure-guided sequence profiles

    DEFF Research Database (Denmark)

    Nielsen, Morten; Lundegaard, Claus; Lund, Ole

    2010-01-01

    CPHmodels-3.0 is a web server predicting protein 3D structure by use of single template homology modeling. The server employs a hybrid of the scoring functions of CPHmodels-2.0 and a novel remote homology-modeling algorithm. A query sequence is first attempted modeled using the fast CPHmodels-2.......0 profile-profile scoring function suitable for close homology modeling. The new computational costly remote homology-modeling algorithm is only engaged provided that no suitable PDB template is identified in the initial search. CPHmodels-3.0 was benchmarked in the CASP8 competition and produced models.......3 A. These performance values place the CPHmodels-3.0 method in the group of high performing 3D prediction tools. Beside its accuracy, one of the important features of the method is its speed. For most queries, the response time of the server is...

  1. Competition between replicative and translesion polymerases during homologous recombination repair in Drosophila.

    Directory of Open Access Journals (Sweden)

    Daniel P Kane

    Full Text Available In metazoans, the mechanism by which DNA is synthesized during homologous recombination repair of double-strand breaks is poorly understood. Specifically, the identities of the polymerase(s that carry out repair synthesis and how they are recruited to repair sites are unclear. Here, we have investigated the roles of several different polymerases during homologous recombination repair in Drosophila melanogaster. Using a gap repair assay, we found that homologous recombination is impaired in Drosophila lacking DNA polymerase zeta and, to a lesser extent, polymerase eta. In addition, the Pol32 protein, part of the polymerase delta complex, is needed for repair requiring extensive synthesis. Loss of Rev1, which interacts with multiple translesion polymerases, results in increased synthesis during gap repair. Together, our findings support a model in which translesion polymerases and the polymerase delta complex compete during homologous recombination repair. In addition, they establish Rev1 as a crucial factor that regulates the extent of repair synthesis.

  2. On some homological functors of a Bieberbach group with symmetric point group

    Science.gov (United States)

    Ting, Tan Yee; Idrus, Nor'ashiqin Mohd; Masri, Rohaidah; Ladi, Nor Fadzilah Abdul

    2017-05-01

    Bieberbach groups with symmetric point group are polycyclic. The properties of the groups can be explored by computing their homological functors. In this paper, some homological functors of a Bieberbach group with symmetric point group, such as the Schur multiplier and the G-trivial subgroup of the nonabelian tensor square, are generalized up to finite dimension and are represented in the form of direct product of cyclic groups.

  3. Double Strand Break Repair, one mechanism can hide another: Alternative non-homologous end joining

    International Nuclear Information System (INIS)

    Rass, E.; Grabarz, A.; Bertrand, P.; Lopez, B.S.

    2012-01-01

    DNA double strand breaks are major cytotoxic lesions encountered by the cells. They can be induced by ionizing radiation or endogenous stress and can lead to genetic instability. Two mechanisms compete for the repair of DNA double strand breaks: homologous recombination and non-homologous end joining (NHEJ). Homologous recombination requires DNA sequences homology and is initiated by single strand resection. Recently, advances have been made concerning the major steps and proteins involved in resection. NHEJ, in contrast, does not require sequence homology. The existence of a DNA double strand break repair mechanism, independent of KU and ligase IV, the key proteins of the canonical non homologous end joining pathway, has been revealed lately and named alternative non homologous end joining. The hallmarks of this highly mutagenic pathway are deletions at repair junctions and frequent use of distal micro-homologies. This mechanism is also initiated by a single strand resection of the break. The aim of this review is firstly to present recent data on single strand resection, and secondly the alternative NHEJ pathway, including a discussion on the fidelity of NHEJ. Based on current knowledge, canonical NHEJ does not appear as an intrinsically mutagenic mechanism, but in contrast, as a conservative one. The structure of broken DNA ends actually dictates the quality repair of the alternative NHEJ and seems the actual responsible for the mutagenesis attributed beforehand to the canonical NHEJ. The existence of this novel DNA double strand breaks repair mechanism needs to be taken into account in the development of radiosensitizing strategies in order to optimise the efficiency of radiotherapy. (authors)

  4. Somatic association of telocentric chromosomes carrying homologous centromeres in common wheat.

    Science.gov (United States)

    Mello-Sampayo, T

    1973-01-01

    Measurements of distances between telocentric chromosomes, either homologous or representing the opposite arms of a metacentric chromosome (complementary telocentrics), were made at metaphase in root tip cells of common wheat carrying two homologous pairs of complementary telocentrics of chromosome 1 B or 6 B (double ditelosomic 1 B or 6 B). The aim was to elucidate the relative locations of the telocentric chromosomes within the cell. The data obtained strongly suggest that all four telocentrics of chromosome 1 B or 6 B are spacially and simultaneously co-associated. In plants carrying two complementary (6 B (S) and 6 B (L)) and a non-related (5 B (L)) telocentric, only the complementary chromosomes were found to be somatically associated. It is thought, therefore, that the somatic association of chromosomes may involve more than two chromosomes in the same association and, since complementary telocentrics are as much associated as homologous, that the homology between centromeres (probably the only homologous region that exists between complementary telocentrics) is a very important condition for somatic association of chromosomes. The spacial arrangement of chromosomes was studied at anaphase and prophase and the polar orientation of chromosomes at prophase was found to resemble anaphase orientation. This was taken as good evidence for the maintenance of the chromosome arrangement - the Rabl orientation - and of the peripheral location of the centromere and its association with the nuclear membrane. Within this general arrangement homologous telocentric chromosomes were frequently seen to have their centromeres associated or directed towards each other. The role of the centromere in somatic association as a spindle fibre attachment and chromosome binder is discussed. It is suggested that for non-homologous chromosomes to become associated in root tips, the only requirement needed should be the homology of centromeres such as exists between complementary

  5. Recovery of arrested replication forks by homologous recombination is error-prone.

    Directory of Open Access Journals (Sweden)

    Ismail Iraqui

    Full Text Available Homologous recombination is a universal mechanism that allows repair of DNA and provides support for DNA replication. Homologous recombination is therefore a major pathway that suppresses non-homology-mediated genome instability. Here, we report that recovery of impeded replication forks by homologous recombination is error-prone. Using a fork-arrest-based assay in fission yeast, we demonstrate that a single collapsed fork can cause mutations and large-scale genomic changes, including deletions and translocations. Fork-arrest-induced gross chromosomal rearrangements are mediated by inappropriate ectopic recombination events at the site of collapsed forks. Inverted repeats near the site of fork collapse stimulate large-scale genomic changes up to 1,500 times over spontaneous events. We also show that the high accuracy of DNA replication during S-phase is impaired by impediments to fork progression, since fork-arrest-induced mutation is due to erroneous DNA synthesis during recovery of replication forks. The mutations caused are small insertions/duplications between short tandem repeats (micro-homology indicative of replication slippage. Our data establish that collapsed forks, but not stalled forks, recovered by homologous recombination are prone to replication slippage. The inaccuracy of DNA synthesis does not rely on PCNA ubiquitination or trans-lesion-synthesis DNA polymerases, and it is not counteracted by mismatch repair. We propose that deletions/insertions, mediated by micro-homology, leading to copy number variations during replication stress may arise by progression of error-prone replication forks restarted by homologous recombination.

  6. Csk Homologous Kinase, a Potential Regulator of CXCR4-mediated Breast Cancer Cell Metastasis

    Science.gov (United States)

    2010-08-31

    SH2 ) and SH3 domains and lacks the consensus tyrosine phosphorylation and myristylation sites found in Src family kinases . CHK has been shown to...0350 TITLE: Csk Homologous Kinase , a Potential Regulator of CXCR4-mediated Breast Cancer Cell Metastasis PRINCIPAL INVESTIGATOR: Byeong-Chel...1 AUG 2009 - 31 JUL 2010 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-09-1-0350 Csk Homologous Kinase , a Potential Regulator

  7. GLASSgo – Automated and Reliable Detection of sRNA Homologs From a Single Input Sequence

    Directory of Open Access Journals (Sweden)

    Steffen C. Lott

    2018-04-01

    Full Text Available Bacterial small RNAs (sRNAs are important post-transcriptional regulators of gene expression. The functional and evolutionary characterization of sRNAs requires the identification of homologs, which is frequently challenging due to their heterogeneity, short length and partly, little sequence conservation. We developed the GLobal Automatic Small RNA Search go (GLASSgo algorithm to identify sRNA homologs in complex genomic databases starting from a single sequence. GLASSgo combines an iterative BLAST strategy with pairwise identity filtering and a graph-based clustering method that utilizes RNA secondary structure information. We tested the specificity, sensitivity and runtime of GLASSgo, BLAST and the combination RNAlien/cmsearch in a typical use case scenario on 40 bacterial sRNA families. The sensitivity of the tested methods was similar, while the specificity of GLASSgo and RNAlien/cmsearch was significantly higher than that of BLAST. GLASSgo was on average ∼87 times faster than RNAlien/cmsearch, and only ∼7.5 times slower than BLAST, which shows that GLASSgo optimizes the trade-off between speed and accuracy in the task of finding sRNA homologs. GLASSgo is fully automated, whereas BLAST often recovers only parts of homologs and RNAlien/cmsearch requires extensive additional bioinformatic work to get a comprehensive set of homologs. GLASSgo is available as an easy-to-use web server to find homologous sRNAs in large databases.

  8. Effects of polymerization and nucleotide identity on the conformational dynamics of the bacterial actin homolog MreB.

    Science.gov (United States)

    Colavin, Alexandre; Hsin, Jen; Huang, Kerwyn Casey

    2014-03-04

    The assembly of protein filaments drives many cellular processes, from nucleoid segregation, growth, and division in single cells to muscle contraction in animals. In eukaryotes, shape and motility are regulated through cycles of polymerization and depolymerization of actin cytoskeletal networks. In bacteria, the actin homolog MreB forms filaments that coordinate the cell-wall synthesis machinery to regulate rod-shaped growth and contribute to cellular stiffness through unknown mechanisms. Like actin, MreB is an ATPase and requires ATP to polymerize, and polymerization promotes nucleotide hydrolysis. However, it is unclear whether other similarities exist between MreB and actin because the two proteins share low sequence identity and have distinct cellular roles. Here, we use all-atom molecular dynamics simulations to reveal surprising parallels between MreB and actin structural dynamics. We observe that MreB exhibits actin-like polymerization-dependent structural changes, wherein polymerization induces flattening of MreB subunits, which restructures the nucleotide-binding pocket to favor hydrolysis. MreB filaments exhibited nucleotide-dependent intersubunit bending, with hydrolyzed polymers favoring a straighter conformation. We use steered simulations to demonstrate a coupling between intersubunit bending and the degree of flattening of each subunit, suggesting cooperative bending along a filament. Taken together, our results provide molecular-scale insight into the diversity of structural states of MreB and the relationships among polymerization, hydrolysis, and filament properties, which may be applicable to other members of the broad actin family.

  9. CERN exhibition attracts over 100,000 visitors in Belgrade

    CERN Multimedia

    Antonella Del Rosso

    2012-01-01

    “This must be an 'all-time record',” says Ray Lewis, CERN travelling exhibition manager. “In all my time with the various permanent and travelling exhibitions that have taken place locally and within our Member States I have never experienced such figures.”   Zarko Obradovic (left), Serbian Minister of Education, Science and Technology, and Rolf Heuer (right), CERN Director-General, at the CERN travelling exhibition in Belgrade. Indeed, in approximately 20 days of exhibition time about 120,000 people, mainly school visiters and the general public, visited the 100 m2 CERN mini-exhibition. It was set up in the centre of Belgrade in October, in association with the meeting of the Restricted European Committee for Future Accelerators (RECFA). After attending the RECFA meeting, CERN's Director-General Rofl Heuer opened the CERN exhibition on the evening of 19 October. Lectures about CERN were held every afternoon, and two public de...

  10. Maintaining students’ Speaking Fluency through Exhibition Examination in Sociolinguistic Studies

    Directory of Open Access Journals (Sweden)

    Khusnul Qhotimah Yuliatuty

    2013-07-01

    Full Text Available Using exhibition for the final project in Sociolinguistic study is really interesting for Universitas Siswa Bangsa Internasional students, especially for 2011 English Department students. Exhibition becomes interesting because this is the new thing to conduct the final project for English Department students’ cohort 2011 at Universitas Siswa Bangsa Internasional. The lecturer divides the students into pairs and each pairs should master one content or topic in Sociolinguistic study.  The students will do the exhibition about the topic that they get in a pairs. The lecturer also gives the students rubric sheet to fill by the visitors. The exhibition will make the students prepare themselves well because they will face many questions about the content which will be delivered by them. Beside, this exhibition also maintains students’ fluency in speaking English because they will explain and answer the questions from visitors with English. This paper tries to focus on how exhibition examination can maintain students’ fluency in speaking English.

  11. The Eugenides Foundation Interactive Exhibition of Science and Technology

    Science.gov (United States)

    Kontogiannis, Ioannis

    2010-01-01

    The Interactive Exhibition of Science and Technology is installed in an area of 1200 m2 at the Eugenides Foundation. 65 interactive exhibits, designed by the "Cites des Science et de l' Industrie" are organised in themes, stimulate the visitors' mind and provoke scientific thinking. Parallel activities take place inside the exhibition, such as live science demonstrations, performed by young scientists. Extra material such as news bulletins (short news, science comics and portraits), educational paths and treasure-hunting based games, all available online as well, are prepared on a monthly basis and provided along with the visit to the exhibition. Through these exhibits and activities, scientific facts are made simple and easy to comprehend using modern presentation tools. We present details on how this exhibition acts complementary to the science education provided by schools, making it a highly sophisticated educational tool.

  12. Students-exhibits interaction at a science center

    Science.gov (United States)

    Botelho, Agostinho; Morais, Ana M.

    2006-12-01

    In this study we investigate students' learning during their interaction with two exhibits at a science center. Specifically, we analyze both students' procedures when interacting with exhibits and their understanding of the scientific concepts presented therein. Bernstein's theory of pedagogic discourse (1990, 2000) provided the sociological foundation to assess the exhibit-student interaction and allowed analysis of the influence of the characteristics of students, exhibits, and interactions on students' learning. Eight students (ages 12ndash;13 years of age) with distinct sociological characteristics participated in the study. Several findings emerged from the results. First, the characteristics of the students, exhibits, and interactions appeared to influence student learning. Second, to most students, what they did interactively (procedures) seems not to have had any direct consequence on what they learned (concept understanding). Third, the data analysis suggest an important role for designers and teachers in overcoming the limitations of exhibit-student interaction.

  13. Bioaugmentation with endophytic bacterium E6S homologous to Achromobacter piechaudii enhances metal rhizoaccumulation in host Sedum plumbizincicola

    Directory of Open Access Journals (Sweden)

    Ying eMa

    2016-02-01

    Full Text Available Application of hyperaccumulator–endophyte symbiotic systems is a potential approach to improve phytoremediation efficiency, since some beneficial endophytic bacteria are able to detoxify heavy metals, alter metal solubility in soil and facilitate plant growth. The objective of this study was to isolate multi-metal resistant and plant beneficial endophytic bacteria and to evaluate their role in enhancing plant growth and metal accumulation/translocation. The metal resistant endophytic bacterial strain E6S was isolated from stems of the Zn/Cd hyperaccumulator plant Sedum plumbizincicola growing in metalliferous mine soils using Dworkin and Foster salts minimal agar medium with 1-aminocyclopropane-1-carboxylate (ACC as the sole nitrogen source, and identified as homologous to Achromobacter piechaudii based on morphological and biochemical characteristics, partial 16S rDNA sequence and phylogenetic analysis. Strain E6S showed high level of resistance to various metals (Cd, Zn and Pb. Besides utilizing ACC, strain E6S exhibited plant beneficial traits, such as solubilization of phosphate and production of indole-3-acetic acid. Inoculation with E6S significantly increased the bioavailability of Cd, Zn and Pb in soil. In addition, bacterial cells bound considerable amounts of metal ions in the following order: Zn ˃ Cd ˃ Pb. Inoculation of E6S significantly stimulated plant biomass, uptake and bioaccumulation of Cd, Zn and Pb. However, E6S greatly reduced the root to shoot translocation of Cd and Zn, indicating that bacterial inoculation assisted the host plant to uptake and store heavy metals in its root system. Inoculation with the endophytic bacterium E6S homologous to A. piechaudii can improve phytostabilization of metalliferous soils due to its effective ability to enhance in situ metal rhizoaccumulation in plants.

  14. Homology-guided mutational analysis reveals the functional requirements for antinociceptive specificity of collapsin response mediator protein 2-derived peptides.

    Science.gov (United States)

    Moutal, Aubin; Li, Wennan; Wang, Yue; Ju, Weina; Luo, Shizhen; Cai, Song; François-Moutal, Liberty; Perez-Miller, Samantha; Hu, Jackie; Dustrude, Erik T; Vanderah, Todd W; Gokhale, Vijay; Khanna, May; Khanna, Rajesh

    2017-02-05

    N-type voltage-gated calcium (Ca v 2.2) channels are critical determinants of increased neuronal excitability and neurotransmission accompanying persistent neuropathic pain. Although Ca v 2.2 channel antagonists are recommended as first-line treatment for neuropathic pain, calcium-current blocking gabapentinoids inadequately alleviate chronic pain symptoms and often exhibit numerous side effects. Collapsin response mediator protein 2 (CRMP2) targets Ca v 2.2 channels to the sensory neuron membrane and allosterically modulates their function. A 15-amino-acid peptide (CBD3), derived from CRMP2, disrupts the functional protein-protein interaction between CRMP2 and Ca v 2.2 channels to inhibit calcium influx, transmitter release and acute, inflammatory and neuropathic pain. Here, we have mapped the minimal domain of CBD3 necessary for its antinociceptive potential. Truncated as well as homology-guided mutant versions of CBD3 were generated and assessed using depolarization-evoked calcium influx in rat dorsal root ganglion neurons, binding between CRMP2 and Ca v 2.2 channels, whole-cell voltage clamp electrophysiology and behavioural effects in two models of experimental pain: post-surgical pain and HIV-induced sensory neuropathy induced by the viral glycoprotein 120. The first six amino acids within CBD3 accounted for all in vitro activity and antinociception. Spinal administration of a prototypical peptide (TAT-CBD3-L5M) reversed pain behaviours. Homology-guided mutational analyses of these six amino acids identified at least two residues, Ala1 and Arg4, as being critical for antinociception in two pain models. These results identify an antinociceptive scaffold core in CBD3 that can be used for development of low MW mimetics of CBD3. © 2017 The British Pharmacological Society.

  15. Exterior Site Occupancy Infers Chloride-Induced Proton Gating in a Prokaryotic Homolog of the ClC Chloride Channel

    Science.gov (United States)

    Bostick, David L.; Berkowitz, Max L.

    2004-01-01

    The ClC family of anion channels mediates the efficient, selective permeation of Cl− across the biological membranes of living cells under the driving force of an electrochemical gradient. In some eukaryotes, these channels are known to exhibit a unique gating mechanism, which appears to be triggered by the permeant Cl− anion. We infer details of this gating mechanism by studying the free energetics of Cl− occupancy in the pore of a prokaryotic ClC homolog. These free energetics were gleaned from 30 ns of molecular dynamics simulation on an ∼133,000-atom system consisting of a hydrated membrane embedded StClC transporter. The binding sites for Cl− in the transporter were determined for the cases where the putative gating residue, Glu148, was protonated and unprotonated. When the glutamate gate is protonated, Cl− favorably occupies an exterior site, Sext, to form a queue of anions in the pore. However, when the glutamate gate is unprotonated, Cl− cannot occupy this site nor, consequently, pass through the pore. An additional, previously undetected, site was found in the pore near the outer membrane that exists regardless of the protonation state of Glu148. Although this suggests that, for the prokaryotic homolog, protonation of Glu148 may be the first step in transporting Cl− at the expense of H+ transport in the opposite direction, an evolutionary argument might suggest that Cl− opens the ClC gate in eukaryotic channels by inducing the conserved glutamate's protonation. During an additional 20 ns free dynamics simulation, the newly discovered outermost site, Sout, and the innermost site, Sint, were seen to allow spontaneous exchange of Cl− ions with the bulk electrolyte while under depolarization conditions. PMID:15345547

  16. Evolution and virulence contributions of the autotransporter proteins YapJ and YapK of Yersinia pestis CO92 and their homologs in Y. pseudotuberculosis IP32953.

    Science.gov (United States)

    Lenz, Jonathan D; Temple, Brenda R S; Miller, Virginia L

    2012-10-01

    Yersinia pestis, the causative agent of plague, evolved from the gastrointestinal pathogen Yersinia pseudotuberculosis. Both species have numerous type Va autotransporters, most of which appear to be highly conserved. In Y. pestis CO92, the autotransporter genes yapK and yapJ share a high level of sequence identity. By comparing yapK and yapJ to three homologous genes in Y. pseudotuberculosis IP32953 (YPTB0365, YPTB3285, and YPTB3286), we show that yapK is conserved in Y. pseudotuberculosis, while yapJ is unique to Y. pestis. All of these autotransporters exhibit >96% identity in the C terminus of the protein and identities ranging from 58 to 72% in their N termini. By extending this analysis to include homologous sequences from numerous Y. pestis and Y. pseudotuberculosis strains, we determined that these autotransporters cluster into a YapK (YPTB3285) class and a YapJ (YPTB3286) class. The YPTB3286-like gene of most Y. pestis strains appears to be inactivated, perhaps in favor of maintaining yapJ. Since autotransporters are important for virulence in many bacterial pathogens, including Y. pestis, any change in autotransporter content should be considered for its impact on virulence. Using established mouse models of Y. pestis infection, we demonstrated that despite the high level of sequence identity, yapK is distinct from yapJ in its contribution to disseminated Y. pestis infection. In addition, a mutant lacking both of these genes exhibits an additive attenuation, suggesting nonredundant roles for yapJ and yapK in systemic Y. pestis infection. However, the deletion of the homologous genes in Y. pseudotuberculosis does not seem to impact the virulence of this organism in orogastric or systemic infection models.

  17. Creating National Narrative: The Red Guard Art Exhibitions and the National Exhibitions in the Chinese Cultural Revolution 1966 - 1976

    Directory of Open Access Journals (Sweden)

    Winnie Tsang

    2014-06-01

    Full Text Available The artistic development in China experienced drastic changes during the Cultural Revolution from 1966 to 1976. Traditional Chinese art was denounced, whereas propaganda art became predominant in shaping the public’s loyalty towards the Communist Party and the country. Two major groups of art exhibitions emerged during the Revolution—the unofficial Red Guard art exhibitions organized by student activists in collaboration with local communes and art schools between 1966 and 1968, and the state-run national exhibitions from 1972 to 1975. These exhibitions were significant to this period because they were held frequently in the capital city Beijing and occasionally elsewhere, and through art they presented unique revolutionary beliefs to the Chinese people in a public setting. While the Red Guard art exhibitions and the national exhibitions certainly created different national narratives, I argue that the national exhibitions were in fact an attempt to revise the national narrative created by the Red Guard art exhibitions in order to re-establish a more utopian, consistent, and official national narrative. This paper unravels the intricate relationship between the two groups of exhibitions by comparing their exhibition venues, ideological focuses, work selection and quality editing. 

  18. High frequency of phylogenetically diverse reductive dehalogenase-homologous genes in deep subseafloor sedimentary metagenomes

    Directory of Open Access Journals (Sweden)

    Mikihiko eKawai

    2014-03-01

    Full Text Available Marine subsurface sediments on the Pacific margin harbor diverse microbial communities even at depths of several hundreds meters below the seafloor (mbsf or more. Previous PCR-based molecular analysis showed the presence of diverse reductive dehalogenase gene (rdhA homologs in marine subsurface sediment, suggesting that anaerobic respiration of organohalides is one of the possible energy-yielding pathways in the organic-rich sedimentary habitat. However, primer-independent molecular characterization of rdhA has remained to be demonstrated. Here, we studied the diversity and frequency of rdhA homologs by metagenomic analysis of five different depth horizons (0.8, 5.1, 18.6, 48.5 and 107.0 mbsf at Site C9001 off the Shimokita Peninsula of Japan. From all metagenomic pools, remarkably diverse rdhA-homologous sequences, some of which are affiliated with novel clusters, were observed with high frequency. As a comparison, we also examined frequency of dissimilatory sulfite reductase genes (dsrAB, key functional genes for microbial sulfate reduction. The dsrAB were also widely observed in the metagenomic pools whereas the frequency of dsrAB genes was generally smaller than that of rdhA-homologous genes. The phylogenetic composition of rdhA-homologous genes was similar among the five depth horizons. Our metagenomic data revealed that subseafloor rdhA homologs are more diverse than previously identified from PCR-based molecular studies. Spatial distribution of similar rdhA homologs across wide depositional ages indicates that the heterotrophic metabolic processes mediated by the genes can be ecologically important, functioning in the organic-rich subseafloor sedimentary biosphere.

  19. Partial amino acid sequence of apolipoprotein(a) shows that it is homologous to plasminogen

    International Nuclear Information System (INIS)

    Eaton, D.L.; Fless, G.M.; Kohr, W.J.; McLean, J.W.; Xu, Q.T.; Miller, C.G.; Lawn, R.M.; Scanu, A.M.

    1987-01-01

    Apolipoprotein(a) [apo(a)] is a glycoprotein with M/sub r/ ∼ 280,000 that is disulfide linked to apolipoprotein B in lipoprotein(a) particles. Elevated plasma levels of lipoprotein(a) are correlated with atherosclerosis. Partial amino acid sequence of apo(a) shows that it has striking homology to plasminogen. Plasminogen is a plasma serine protease zymogen that consists of five homologous and tandemly repeated domains called kringles and a trypsin-like protease domain. The amino-terminal sequence obtained for apo(a) is homologous to the beginning of kringle 4 but not the amino terminus of plasminogen. Apo(a) was subjected to limited proteolysis by trypsin or V8 protease, and fragments generated were isolated and sequenced. Sequences obtained from several of these fragments are highly (77-100%) homologous to plasminogen residues 391-421, which reside within kringle 4. Analysis of these internal apo(a) sequences revealed that apo(a) may contain at least two kringle 4-like domains. A sequence obtained from another tryptic fragment also shows homology to the end of kringle 4 and the beginning of kringle 5. Sequence data obtained from the two tryptic fragments shows homology with the protease domain of plasminogen. One of these sequences is homologous to the sequences surrounding the activation site of plasminogen. Plasminogen is activated by the cleavage of a specific arginine residue by urokinase and tissue plasminogen activator; however, the corresponding site in apo(a) is a serine that would not be cleaved by tissue plasminogen activator or urokinase. Using a plasmin-specific assay, no proteolytic activity could be demonstrated for lipoprotein(a) particles. These results suggest that apo(a) contains kringle-like domains and an inactive protease domain

  20. Exhibition at CERN's Globe of Science and Innovation

    CERN Multimedia

    Claudia Marcelloni

    2006-01-01

    Here we see pictures of displays at one of the exhibitions held at the Globe of Science and Innovation taken in September 2006. Located opposite the main CERN site, the Globe houses many public exhibitions throughout the year covering many topics from astronomy to particle physics.

  1. Designing Art Exhibitions in an Educational Virtual World

    Science.gov (United States)

    Julian, June; Crooks, Julian

    2011-01-01

    Demonstrating the multiple features of the Cerulean Gallery in Second Life, this research report showcases several exemplar exhibits created by students, artists, and museums. Located in The Educational Media Center, a Second Life teaching and social space, the Cerulean Gallery exhibits functioned as case studies that tested its effectiveness as…

  2. 7 CFR Exhibit A to Subpart Jj of... - Agreement Form

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Agreement Form A Exhibit A to Subpart JJ of Part 2045...) ADMINISTRATIVE REGULATIONS GENERAL Rural Development-Utilization of Gratuitous Services Pt. 2045, Subpt. JJ, Exh. A Exhibit A to Subpart JJ of Part 2045—Agreement Form for utilization of employees of (official...

  3. Perspectives on ... Multiculturalism and Library Exhibits: Sites of Contested Representation

    Science.gov (United States)

    Reece, Gwendolyn J.

    2005-01-01

    This article analyzes a multicultural library exhibit presenting the Palestinian/Israeli conflict as a site of contested representation. Qualitative methodology is used to interrogate the exhibit and its audience reception. Drawing on insights from critical pedagogy, implications for libraries arising from this case study are given and suggestions…

  4. Informing the Development of Science Exhibitions through Educational Research

    Science.gov (United States)

    Laherto, Antti

    2013-01-01

    This paper calls for greater use of educational research in the development of science exhibitions. During the past few decades, museums and science centres throughout the world have placed increasing emphasis on their educational function. Although exhibitions are the primary means of promoting visitors' learning, educational research is not…

  5. 75 FR 6079 - Culturally Significant Objects Imported for Exhibition

    Science.gov (United States)

    2010-02-05

    ... cultural significance. The objects are imported pursuant to loan agreements with the foreign owners or custodians. I also determine that the exhibition or display of the exhibit objects at the Yale Center for... Professional and Cultural Exchanges, Bureau of Educational and Cultural Affairs, Department of State. [FR Doc...

  6. 7 CFR Exhibit A to Subpart B of... - [Reserved

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false [Reserved] A Exhibit A to Subpart B of Part 1900 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS... REGULATIONS GENERAL Adverse Decisions and Administrative Appeals Exhibit A to Subpart B of Part 1900 [Reserved] ...

  7. 19 CFR 212.11 - Net worth exhibit.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Net worth exhibit. 212.11 Section 212.11 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 212.11 Net worth exhibit...

  8. Outreach to Science Faculty and Students through Research Exhibitions

    Science.gov (United States)

    Chan, Tina; Hebblethwaite, Chris

    2014-01-01

    Penfield Library at the State University of New York at Oswego (SUNY Oswego) has a gallery exhibit space near the front entrance that is used to showcase student-faculty research and art class projects. This article features the library's outreach efforts to science faculty and students through research exhibitions. The library held an exhibition…

  9. Modelling the Future: Exhibitions and the Materiality of Education

    Science.gov (United States)

    Lawn, Martin, Ed.

    2009-01-01

    The role of World Exhibitions in the 19th and early 20th centuries was to confirm a relation between the nation state and modernity. As a display about industries, inventions and identities, the Exhibition, in a sense, put entire nations into an elevated, viewable space. It is a significant element in modernity as comparisons can be made, progress…

  10. CERN Industrials Exhibitions - Over 30 Years of Tradition

    CERN Multimedia

    2001-01-01

    Industrial exhibitions have been part of the CERN landscape for 33 years. At least once each year several companies from the same country come to CERN to present their products and services. Now, a new scheme of one-day visits is giving potential exhibitors at CERN a lighter option. The United Kingdom inaugurated the Industrial Exhibitions in 1968, and it wasn't till 1971 that other countries staged exhibitions at CERN. This photo was taken in 1969, at the second British exhibition, where 16 companies were present. Four years after joining CERN, Poland inaugurated its first exhibition at CERN in 1995 in the presence of the former Director-General Chris Llewellyn-Smith. Almost all the Member States have held industrial exhibitions at the Organization. May '68 wasn't only revolutionary in Paris. For the very first time, an industrial exhibition took place at CERN. Great Britain was first to come with eight companies and remains until this day the most devoted country to the programme with 17 exhibitions and ...

  11. Presentation and exhibition activities for promoting theexportof transport services

    Directory of Open Access Journals (Sweden)

    Darya Vladimirovna Nesterova

    2012-03-01

    Full Text Available Development of presentation and exhibition activities is considered as an important factor in providing new competitive advantages at the strategic markets for exporting of transportation services. A specific role for exhibition activities as a factor to overcome market failures arose from imperfect information and incomplete markets is displayed. Exhibitions are considered as a true reflection of most market parameters, as a means to get correct information concerning market capacity and its borders, as an instrument to access to new markets. At the firm level presentation and branding activities should be considered as a modern technology (especially it concerns Russian companies which provide to hold up already existed markets and to conquer new ones. Presentation and branding activities are an effective technology to promote company trade-mark, competitive advantages for market demand increasing. Comparative analysis of the main exhibitions on transport and logistics issues is fulfilled on the data basecollected by authors. Data observes geographical distribution of transport exhibition and exhibition facilities development at several regions for the last years. The analyses allow to revealing a geographical structure of the exhibitions and its distribution by type of transport. The most promising and economically favorable exhibition areas for the promotion of Russian transport services are shown.

  12. The AAAI 2006 Mobile Robot Competition and Exhibition

    OpenAIRE

    Rybski, Paul E.; Forbes, Jeffrey; Burhans, Debra; Dodds, Zach; Oh, Paul; Scheutz, Matthias; Avanzato, Bob

    2007-01-01

    The Fifteenth Annual AAAI Robot Competition and Exhibition was held at the Twenty-First National Conference on Artificial Intelligence in Boston, Massachusetts, in July 2006. This article describes the events that were held at the conference, including the Scavenger Hunt, Human Robot Interaction, and Robot Exhibition.

  13. Sponsorship and exhibitions at Nordic science centres and museums

    DEFF Research Database (Denmark)

    Davidsson, Eva; Sørensen, Helene

    2010-01-01

    Science and technology centres (STC) and science museums tend increasingly to rely on external economic support in order to create new exhibitions. But in what ways may the economic situation affect what is presented in their exhibitions? This article aims to explore how staff members consider...

  14. The Signatures of the Invisible exhibition in Geneva

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The artist Paola Pivi with her work at the Signatures of the Invisible exhibition in Geneva during February 2002. This piece with needles suspended on nylon thread 'detects' people as they approach. The exhibition was for art inspired by research carried out at CERN.

  15. Cellulase enzyme: Homology modeling, binding site identification and molecular docking

    Science.gov (United States)

    Selvam, K.; Senbagam, D.; Selvankumar, T.; Sudhakar, C.; Kamala-Kannan, S.; Senthilkumar, B.; Govarthanan, M.

    2017-12-01

    Cellulase is an enzyme that degrades the linear polysaccharide like cellulose into glucose by breaking the β-1,4- glycosidic bonds. These enzymes are the third largest enzymes with a great potential towards the ethanol production and play a vital role in degrading the biomass. The production of ethanol depends upon the ability of the cellulose to utilize the wide range of substrates. In this study, the 3D structure of cellulase from Acinetobacter sp. was modeled by using Modeler 9v9 and validated by Ramachandran plot. The accuracy of the predicted 3D structure was checked using Ramachandran plot analysis showed that 81.1% in the favored region, compatibility of an atomic model (3D) with amino acid sequence (1D) for the model was observed as 78.21% and 49.395% for Verify 3D and ERRAT at SAVES server. As the binding efficacy with the substrate might suggests the choice of the substrate as carbon and nitrogen sources, the cellobiose, cellotetraose, cellotetriose and laminaribiose were employed in the docking studies. The docking of cellobiose, cellotetraose, cellotetriose and laminaribiose with cellulase exhibited the binding energy of -6.1523 kJ/mol, -7.8759 kJ/mol,-6.1590 kJ/mol and -6.7185 kJ/mol, respectively. These docking studies revealed that cellulase has the greater potential towards the cellotetraose as a substrate for the high yield of ethanol.

  16. Displaying lives: the narrative of objects in biographical exhibitions

    Directory of Open Access Journals (Sweden)

    Caterina Albano

    2007-03-01

    Full Text Available Biographical exhibitions are a museum practice that asks for critical consideration. Grounding the argument in critical theory, social studies and museum theory, the article explores the narrative function of objects in biographical exhibitions by addressing the social significance of objects in relation to biography and their relevance when presented into an exhibition display. Central is the concept of objects as ‘biographical relics’ that are culturally fetishized in biographical narratives. This raises questions about biographical reliability and the cultural role that such objects plays in exhibition narratives as bearers of reality and as metonymical icons of the biographical subject. The article considers examples of biographical exhibitions of diverse figures such as Gregor Mendel, Madame de Pompadour and Roland Barthes, and the role that personal items, but also portraits and photographs, play in them.

  17. CERN’s travelling exhibition goes to Austria

    CERN Multimedia

    Mélissa Lanaro

    2011-01-01

    Since April 2009 CERN’s travelling exhibition has been touring through some of the Organization's Member States. After Italy and Denmark it has been on show since February at Austria’s Hartberg Ökopark, a very popular science museum situated some one hundred kilometres from Vienna. To coincide with the CERN exhibition, Austria’s scientific community has organised a series of events for the general public which have had marked success. The exhibition's next destination will be Portugal and preparations are already underway to ensure that it is another resounding success   The travelling exhibition was designed in collaboration with the University of Geneva, as part of the celebrations for its 450th anniversary, and has already notched up a good number of kilometres as it travels from country to country. “In 2010 the exhibition already had around 55,000 visitors,” explains Rolf Landua, who heads the Education Group. Since its inauguration ...

  18. Genetically encoded fluorescent voltage sensors using the voltage-sensing domain of Nematostella and Danio phosphatases exhibit fast kinetics.

    Science.gov (United States)

    Baker, Bradley J; Jin, Lei; Han, Zhou; Cohen, Lawrence B; Popovic, Marko; Platisa, Jelena; Pieribone, Vincent

    2012-07-15

    A substantial increase in the speed of the optical response of genetically encoded fluorescent protein voltage sensors (FP voltage sensors) was achieved by using the voltage-sensing phosphatase genes of Nematostella vectensis and Danio rerio. A potential N. vectensis voltage-sensing phosphatase was identified in silico. The voltage-sensing domain (S1-S4) of the N. vectensis homolog was used to create an FP voltage sensor called Nema. By replacing the phosphatase with a cerulean/citrine FRET pair, a new FP voltage sensor was synthesized with fast off kinetics (Tau(off)voltage-sensing phosphatase homolog, designated Zahra and Zahra 2, exhibited fast on and off kinetics within 2ms of the time constants observed with the organic voltage-sensitive dye, di4-ANEPPS. Mutagenesis of the S4 region of the Danio FP voltage sensor shifted the voltage dependence to more negative potentials but did not noticeably affect the kinetics of the optical signal. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Genetically-encoded fluorescent voltage sensors using the voltage-sensing domain of Nematostella and Danio phosphatases exhibit fast kinetics

    Science.gov (United States)

    Baker, Bradley J.; Jin, Lei; Han, Zhou; Cohen, Lawrence B.; Popovic, Marko; Platisa, Jelena; Pieribone, Vincent

    2012-01-01

    A substantial increase in the speed of the optical response of genetically-encoded Fluorescent Protein voltage sensors (FP voltage sensors) was achieved by using the voltage-sensing phosphatase genes of Nematostella vectensis and Danio rerio. A potential N. vectensis voltage-sensing phosphatase was identified in silico. The voltage-sensing domain (S1–S4) of the N. vectensis homolog was used to create an FP voltage sensor called Nema. By replacing the phosphatase with a cerulean/citrine FRET pair, a new FP voltage sensor was synthesized with fast off kinetics (Tauoff voltage-sensing phosphatase homolog, designated Zahra and Zahra 2, exhibited fast on and off kinetics within 2 msec of the time constants observed with the organic voltage-sensitive dye, di4-ANEPPS. Mutagenesis of the S4 region of the Danio FP voltage sensor shifted the voltage dependence to more negative potentials but did not noticeably affect the kinetics of the optical signal. PMID:22634212

  20. Structure-based design of an osteoclast-selective, nonpeptide Src homology 2 inhibitor with in vivo antiresorptive activity

    Science.gov (United States)

    Shakespeare, William; Yang, Michael; Bohacek, Regine; Cerasoli, Franklin; Stebbins, Karin; Sundaramoorthi, Raji; Azimioara, Mihai; Vu, Chi; Pradeepan, Selvi; Metcalf, Chester; Haraldson, Chad; Merry, Taylor; Dalgarno, David; Narula, Surinder; Hatada, Marcos; Lu, Xiaode; van Schravendijk, Marie Rose; Adams, Susan; Violette, Shelia; Smith, Jeremy; Guan, Wei; Bartlett, Catherine; Herson, Jay; Iuliucci, John; Weigele, Manfred; Sawyer, Tomi

    2000-01-01

    Targeted disruption of the pp60src (Src) gene has implicated this tyrosine kinase in osteoclast-mediated bone resorption and as a therapeutic target for the treatment of osteoporosis and other bone-related diseases. Herein we describe the discovery of a nonpeptide inhibitor (AP22408) of Src that demonstrates in vivo antiresorptive activity. Based on a cocrystal structure of the noncatalytic Src homology 2 (SH2) domain of Src complexed with citrate [in the phosphotyrosine (pTyr) binding pocket], we designed 3′,4′-diphosphonophenylalanine (Dpp) as a pTyr mimic. In addition to its design to bind Src SH2, the Dpp moiety exhibits bone-targeting properties that confer osteoclast selectivity, hence minimizing possible undesired effects on other cells that have Src-dependent activities. The chemical structure AP22408 also illustrates a bicyclic template to replace the post-pTyr sequence of cognate Src SH2 phosphopeptides such as Ac-pTyr-Glu-Glu-Ile (1). An x-ray structure of AP22408 complexed with Lck (S164C) SH2 confirmed molecular interactions of both the Dpp and bicyclic template of AP22408 as predicted from molecular modeling. Relative to the cognate phosphopeptide, AP22408 exhibits significantly increased Src SH2 binding affinity (IC50 = 0.30 μM for AP22408 and 5.5 μM for 1). Furthermore, AP22408 inhibits rabbit osteoclast-mediated resorption of dentine in a cellular assay, exhibits bone-targeting properties based on a hydroxyapatite adsorption assay, and demonstrates in vivo antiresorptive activity in a parathyroid hormone-induced rat model. PMID:10944210

  1. Assembly and dynamics of the bacteriophage T4 homologous recombination machinery

    Directory of Open Access Journals (Sweden)

    Morrical Scott W

    2010-12-01

    Full Text Available Abstract Homologous recombination (HR, a process involving the physical exchange of strands between homologous or nearly homologous DNA molecules, is critical for maintaining the genetic diversity and genome stability of species. Bacteriophage T4 is one of the classic systems for studies of homologous recombination. T4 uses HR for high-frequency genetic exchanges, for homology-directed DNA repair (HDR processes including DNA double-strand break repair, and for the initiation of DNA replication (RDR. T4 recombination proteins are expressed at high levels during T4 infection in E. coli, and share strong sequence, structural, and/or functional conservation with their counterparts in cellular organisms. Biochemical studies of T4 recombination have provided key insights on DNA strand exchange mechanisms, on the structure and function of recombination proteins, and on the coordination of recombination and DNA synthesis activities during RDR and HDR. Recent years have seen the development of detailed biochemical models for the assembly and dynamics of presynaptic filaments in the T4 recombination system, for the atomic structure of T4 UvsX recombinase, and for the roles of DNA helicases in T4 recombination. The goal of this chapter is to review these recent advances and their implications for HR and HDR mechanisms in all organisms.

  2. Regulation of Rad51-Mediated Homologous Recombination by BRCA2, DSS1 and RAD52

    DEFF Research Database (Denmark)

    Rants, Louise Olthaver Juhl

    Homologous recombination (HR) provides a mechanism to restore integrity and maintain stability of the genetic material. HR is a major pathway for repair of DNA double-strand breaks (DSB), recovery of broken replication forks and generation of meiotic crossovers. The defining step in HR is homolog......Homologous recombination (HR) provides a mechanism to restore integrity and maintain stability of the genetic material. HR is a major pathway for repair of DNA double-strand breaks (DSB), recovery of broken replication forks and generation of meiotic crossovers. The defining step in HR...... is homologous strand exchange directed by the RecA-related recombinase Rad51. BRCA2 participates in HR by mediating Rad51 homology-directed repair. Both BRCA2 and Rad51 are essential for HR, DNA repair, and the maintenance of genome stability. In the present study, we seek to understand the mechanism of BRCA2...... with RAD52-mediated repair at sites of CPT-induced DNA damage. The synthetic lethality approach using RAD52 small molecule inhibitors in brca-deficient cancers is a promising therapeutic strategy for cancer treatment....

  3. MsDpo4—a DinB Homolog from Mycobacterium smegmatis—Is an Error-Prone DNA Polymerase That Can Promote G:T and T:G Mismatches

    Directory of Open Access Journals (Sweden)

    Amit Sharma

    2012-01-01

    Full Text Available Error-prone DNA synthesis in prokaryotes imparts plasticity to the genome to allow for evolution in unfavorable environmental conditions, and this phenomenon is termed adaptive mutagenesis. At a molecular level, adaptive mutagenesis is mediated by upregulating the expression of specialized error-prone DNA polymerases that generally belong to the Y-family, such as the polypeptide product of the dinB gene in case of E. coli. However, unlike E. coli, it has been seen that expression of the homologs of dinB in Mycobacterium tuberculosis are not upregulated under conditions of stress. These studies suggest that DinB homologs in Mycobacteria might not be able to promote mismatches and participate in adaptive mutagenesis. We show that a representative homolog from Mycobacterium smegmatis (MsDpo4 can carry out template-dependent nucleotide incorporation and therefore is a DNA polymerase. In addition, it is seen that MsDpo4 is also capable of misincorporation with a significant ability to promote G:T and T:G mismatches. The frequency of misincorporation for these two mismatches is similar to that exhibited by archaeal and prokaryotic homologs. Overall, our data show that MsDpo4 has the capacity to facilitate transition mutations and can potentially impart plasticity to the genome.

  4. Rapid Acquisition of Linezolid Resistance in Methicillin-Resistant Staphylococcus aureus: Role of Hypermutation and Homologous Recombination.

    Science.gov (United States)

    Iguchi, Shigekazu; Mizutani, Tomonori; Hiramatsu, Keiichi; Kikuchi, Ken

    2016-01-01

    We previously reported the case of a 64-year-old man with mediastinitis caused by Staphylococcus aureus in which the infecting bacterium acquired linezolid resistance after only 14 days treatment with linezolid. We therefore investigated relevant clinical isolates for possible mechanisms of this rapid acquisition of linezolid resistance. Using clinical S. aureus isolates, we assessed the in vitro mutation rate and performed stepwise selection for linezolid resistance. To investigate homologous recombination, sequences were determined for each of the 23S ribosomal RNA (23S rRNA) loci; analyzed sequences spanned the entirety of each 23S rRNA gene, including domain V, as well as the 16S-23S intergenic spacer regions. We additionally performed next-generation sequencing on clinical strains to identify single-nucleotide polymorphisms compared to the N315 genome. Strains isolated from the patient prior to linezolid exposure (M5-M7) showed higher-level linezolid resistance than N315, and the pre-exposure strain (M2) exhibited more rapid acquisition of linezolid resistance than did N315. However, the mutation rates of these and contemporaneous clinical isolates were similar to those of N315, and the isolates did not exhibit any mutations in hypermutation-related genes. Sequences of the 23S rRNA genes and 16S-23S intergenic spacer regions were identical among the pre- and post-exposure clinical strains. Notably, all of the pre-exposure isolates harbored a recQ missense mutation (Glu69Asp) with respect to N315; such a lesion may have affected short sequence recombination (facilitating, for example, recombination among rrn loci). We hypothesize that this mechanism contributed to rapid acquisition of linezolid resistance. Hypermutation and homologous recombination of the ribosomal RNA genes, including 23S rRNA genes, appear not to have been sources of the accelerated acquisition of linezolid resistance observed in our clinical case. Increased frequency of short sequence

  5. Src-homology 2 domain-containing tyrosine phosphatase 2 promotes oral cancer invasion and metastasis

    Science.gov (United States)

    2014-01-01

    Background Tumor invasion and metastasis represent a major unsolved problem in cancer pathogenesis. Recent studies have indicated the involvement of Src-homology 2 domain-containing tyrosine phosphatase 2 (SHP2) in multiple malignancies; however, the role of SHP2 in oral cancer progression has yet to be elucidated. We propose that SHP2 is involved in the progression of oral cancer toward metastasis. Methods SHP2 expression was evaluated in paired oral cancer tissues by using immunohistochemical staining and real-time reverse transcription polymerase chain reaction. Isogenic highly invasive oral cancer cell lines from their respective low invasive parental lines were established using a Boyden chamber assay, and changes in the hallmarks of the epithelial-mesenchymal transition (EMT) were assessed to evaluate SHP2 function. SHP2 activity in oral cancer cells was reduced using si-RNA knockdown or enforced expression of a catalytically deficient mutant to analyze migratory and invasive ability in vitro and metastasis toward the lung in mice in vivo. Results We observed the significant upregulation of SHP2 in oral cancer tissues and cell lines. Following SHP2 knockdown, the oral cancer cells markedly attenuated migratory and invasion ability. We observed similar results in phosphatase-dead SHP2 C459S mutant expressing cells. Enhanced invasiveness was associated with significant upregulation of E-cadherin, vimentin, Snail/Twist1, and matrix metalloproteinase-2 in the highly invasive clones. In addition, we determined that SHP2 activity is required for the downregulation of phosphorylated ERK1/2, which modulates the downstream effectors, Snail and Twist1 at a transcript level. In lung tissue sections of mice, we observed that HSC3 tumors with SHP2 deletion exhibited significantly reduced metastatic capacity, compared with tumors administered control si-RNA. Conclusions Our data suggest that SHP2 promotes the invasion and metastasis of oral cancer cells. These results

  6. Transcription patterns of genes encoding four metallothionein homologs in Daphnia pulex exposed to copper and cadmium are time- and homolog-dependent

    International Nuclear Information System (INIS)

    Asselman, Jana; Shaw, Joseph R.; Glaholt, Stephen P.; Colbourne, John K.; De Schamphelaere, Karel A.C.

    2013-01-01

    Highlights: •Transcription patterns of 4 metallothionein isoforms in Daphnia pulex. •Under cadmium and copper stress these patterns are time-dependent. •Under cadmium and copper stress these patterns are homolog-dependent. •The results stress the complex regulation of metallothioneins. -- Abstract: Metallothioneins are proteins that play an essential role in metal homeostasis and detoxification in nearly all organisms studied to date. Yet discrepancies between outcomes of chronic and acute exposure experiments hamper the understanding of the regulatory mechanisms of their isoforms following metal exposure. Here, we investigated transcriptional differences among four identified homologs (mt1–mt4) in Daphnia pulex exposed across time to copper and cadmium relative to a control. Transcriptional upregulation of mt1 and mt3 was detected on day four following exposure to cadmium, whereas that of mt2 and mt4 was detected on day two and day eight following exposure to copper. These results confirm temporal and metal-specific differences in the transcriptional induction of genes encoding metallothionein homologs upon metal exposure which should be considered in ecotoxicological monitoring programs of metal-contaminated water bodies. Indeed, the mRNA expression patterns observed here illustrate the complex regulatory system associated with metallothioneins, as these patterns are not only dependent on the metal, but also on exposure time and the homolog studied. Further phylogenetic analysis and analysis of regulatory elements in upstream promoter regions revealed a high degree of similarity between metallothionein genes of Daphnia pulex and Daphnia magna, a species belonging to the same genus. These findings, combined with a limited amount of available expression data for D. magna metallothionein genes, tentatively suggest a potential generalization of the metallothionein response system between these Daphnia species

  7. Transcription patterns of genes encoding four metallothionein homologs in Daphnia pulex exposed to copper and cadmium are time- and homolog-dependent

    Energy Technology Data Exchange (ETDEWEB)

    Asselman, Jana, E-mail: jana.asselman@ugent.be [Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Ghent (Belgium); Shaw, Joseph R.; Glaholt, Stephen P. [The School of Public and Environmental Affairs, Indiana University, Bloomington, IN (United States); Colbourne, John K. [School of Biosciences, The University of Birmingham, Birmingham (United Kingdom); De Schamphelaere, Karel A.C. [Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Ghent (Belgium)

    2013-10-15

    Highlights: •Transcription patterns of 4 metallothionein isoforms in Daphnia pulex. •Under cadmium and copper stress these patterns are time-dependent. •Under cadmium and copper stress these patterns are homolog-dependent. •The results stress the complex regulation of metallothioneins. -- Abstract: Metallothioneins are proteins that play an essential role in metal homeostasis and detoxification in nearly all organisms studied to date. Yet discrepancies between outcomes of chronic and acute exposure experiments hamper the understanding of the regulatory mechanisms of their isoforms following metal exposure. Here, we investigated transcriptional differences among four identified homologs (mt1–mt4) in Daphnia pulex exposed across time to copper and cadmium relative to a control. Transcriptional upregulation of mt1 and mt3 was detected on day four following exposure to cadmium, whereas that of mt2 and mt4 was detected on day two and day eight following exposure to copper. These results confirm temporal and metal-specific differences in the transcriptional induction of genes encoding metallothionein homologs upon metal exposure which should be considered in ecotoxicological monitoring programs of metal-contaminated water bodies. Indeed, the mRNA expression patterns observed here illustrate the complex regulatory system associated with metallothioneins, as these patterns are not only dependent on the metal, but also on exposure time and the homolog studied. Further phylogenetic analysis and analysis of regulatory elements in upstream promoter regions revealed a high degree of similarity between metallothionein genes of Daphnia pulex and Daphnia magna, a species belonging to the same genus. These findings, combined with a limited amount of available expression data for D. magna metallothionein genes, tentatively suggest a potential generalization of the metallothionein response system between these Daphnia species.

  8. Application of Glass Fiber Reinforced Cement in Exhibition Decoration Project

    Science.gov (United States)

    Wang, Yao

    2018-02-01

    Through the study of GRC material and its application field, the aesthetic characteristics and functional characteristics of GRC materials are demonstrated. The decorative application and technology of GRC material in an art exhibition center are highlighted. The design, application and construction technology of GRC curtain wall and ceiling board in the interior and exterior decoration of art exhibition hall are discussed in detail. The unique advantages of GRC materials in exhibition engineering decoration are fully reflected. In practical design application, the application principle and method are summarized, and an application procedure is formed. The research proves that GRC materials in the art of building decoration engineering has an underrated advantage.

  9. Statistical properties of chaotic dynamical systems which exhibit strange attractors

    International Nuclear Information System (INIS)

    Jensen, R.V.; Oberman, C.R.

    1981-07-01

    A path integral method is developed for the calculation of the statistical properties of turbulent dynamical systems. The method is applicable to conservative systems which exhibit a transition to stochasticity as well as dissipative systems which exhibit strange attractors. A specific dissipative mapping is considered in detail which models the dynamics of a Brownian particle in a wave field with a broad frequency spectrum. Results are presented for the low order statistical moments for three turbulent regimes which exhibit strange attractors corresponding to strong, intermediate, and weak collisional damping

  10. Knowledge Generation in Technology-Enhanced Health Exhibitions

    DEFF Research Database (Denmark)

    Magnussen, Rikke; Kharlamov, Nikita; Zachariasssen, Maria

    2016-01-01

    This paper presents results from eye-tracking studies of audience interaction and knowledge generation in the technology-enhanced health promotion exhibition PULSE at a science centre in Copenhagen, Denmark. The main purpose of the study was to understand what types of knowledge audiences build...... in health promotion exhibitions designed to include direct physical interaction. The current study is part of the larger PULSE project, which aims to develop innovative health promotion activities that include a science museum exhibition as a key setting. The primary target group is families with children...

  11. Postmodern Exhibition Discourse: Anthropological Study of an Art Display Case.

    Directory of Open Access Journals (Sweden)

    Marta Wieczorek

    2015-12-01

    Full Text Available The article studies tendencies in contemporary museum exhibitions and art display trends. While analysing current status quo of art in the museum context, it discusses the limitations of curatorial impact on the audience perception of the displayed objects. The paper presents a case study of a permanent museum exhibition with an added performance element. As argued in the article, such approach allows a stratified narrative and provokes a dialogue between the audience, performers, and curators, fully reflecting postmodern polyphonic tendency. The aim of the article is to comment on postmodern trends in museology, the status of the displayed art (object, and contemporary exhibition identity.

  12. Comparative anatomy, evolution, and homologies of tetrapod hindlimb muscles, comparison with forelimb muscles, and deconstruction of the forelimb-hindlimb serial homology hypothesis.

    Science.gov (United States)

    Diogo, Rui; Molnar, Julia

    2014-06-01

    For more than two centuries, the idea that the forelimb and hindlimb are serially homologous structures has been accepted without serious question. This study presents the first detailed analysis of the evolution and homologies of all hindlimb muscles in representatives of each major tetrapod group and proposes a unifying nomenclature for these muscles. These data are compared with information obtained previously about the forelimb muscles of tetrapods and the muscles of other gnathostomes in order to address one of the most central and enigmatic questions in evolutionary and comparative anatomy: why are the pelvic and pectoral appendages of gnathostomes generally so similar to each other? An integrative analysis of the new myological data, combined with a review of recent paleontological, developmental, and genetic works and of older studies, does not support serial homology between the structures of these appendages. For instance, many of the strikingly similar forelimb and hindlimb muscles found in each major extant tetrapod taxon were acquired at different geological times and/or have different embryonic origins. These similar muscles are not serial homologues, but the result of evolutionary parallelism/convergence due to a complex interplay of ontogenetic, functional, topological, and phylogenetic constraints/factors. Copyright © 2014 Wiley Periodicals, Inc.

  13. Biochemical and Structural Analysis of Hormone-sensitive Lipase Homolog EstE7: Insight into the Stabilized Dimerization of HSL-Homolog Proteins

    International Nuclear Information System (INIS)

    Nam, Ki Hyun; Park, Sung Ha; Lee, Won Ho; Hwang, Kwang Yeon

    2010-01-01

    Hormone sensitive lipase (HSL) plays a major role in energy homeostasis and lipid metabolism. Several crystal structures of HSL-homolog proteins have been identified, which has led to a better understanding of its molecular function. HSLhomolog proteins exit as both monomer and dimer, but the biochemical and structural basis for such oligomeric states has not been successfully elucidated. Therefore, we determined the crystal structure of HSL-homolog protein EstE7 from a metagenome library at 2.2 A resolution and characterized the oligomeric states of EstE7 both structurally and biochemically. EstE7 protein prefers the dimeric state in solution, which is supported by its higher enzymatic activity in the dimeric state. In the crystal form, EstE7 protein shows two-types of dimeric interface. Specifically, dimerization via the external β8-strand occurred through tight association between two pseudosymmetric folds via salt bridges, hydrogen bonds and van der Waals interactions. This dimer formation was similar to that of other HSL-homolog protein structures such as AFEST, BEFA, and EstE1. We anticipate that our results will provide insight into the oligomeric state of HSLhomolog proteins

  14. Analysis of ultraviolet and X-ray observations of three homologous solar flares from SMM

    Science.gov (United States)

    Cheng, Chung-Chieh; Pallavicini, Roberto

    1987-01-01

    Three homologous flares observed in the UV lines of Fe XXI and O V and in X-rays from the SMM were studied. It was found that: (1) the homology of the flares was most noticeable in Fe XXI and soft X-ray emissions; (2) the three flares shared many of the same loop footprints which were located in O V bright kernals associated with hard X-ray bursts; and (3) in spite of the strong spatial homology, the temporal evolution in UV and X-ray emissions varied from flare to flare. A comparison between the UV observations and photospheric magnetograms revealed that the basic flare configuration was a complex loop system consisting of many loops or bundles of loops.

  15. Homological Order in Three and Four dimensions: Wilson Algebra, Entanglement Entropy and Twist Defects

    Science.gov (United States)

    Roy, Abhishek; Chen, Xiao; Teo, Jeffrey

    2013-03-01

    We investigate homological orders in two, three and four dimensions by studying Zk toric code models on simplicial, cellular or in general differential complexes. The ground state degeneracy is obtained from Wilson loop and surface operators, and the homological intersection form. We compute these for a series of closed 3 and 4 dimensional manifolds and study the projective representations of mapping class groups (modular transformations). Braiding statistics between point and string excitations in (3+1)-dimensions or between dual string excitations in (4+1)-dimensions are topologically determined by the higher dimensional linking number, and can be understood by an effective topological field theory. An algorithm for calculating entanglemnent entropy of any bipartition of closed manifolds is presented, and its topological signature is completely characterized homologically. Extrinsic twist defects (or disclinations) are studied in 2,3 and 4 dimensions and are shown to carry exotic fusion and braiding properties. Simons Fellowship

  16. Coal and biomass-based chemicals via carbonylation, hydroformylation and homologation reactions

    Energy Technology Data Exchange (ETDEWEB)

    Sunavala, P.D.; Raghunath, B.

    The paper emphasizes the importance of carbonylation, hydroformylation and homologation reactions in the manufacture of organic chemicals (such as acetic acid, acetic anhydride, cellulose acetate, vinyl acetate monomer, aliphatic amines, isocyanates, methanol, ethanol, n-butanol, ethylene glycol, acrylic acid, etc.) from coal and biomass feedstocks. Topics covered are: synthesis of acetic acid; manufacture of acetic anhydride; synthesis of vinyl acetate monomer by carbonylation; synthesis of aliphatic amines by hydroformylation; synthesis of organic diisocyanates; ethanol synthesis by homologation of methanol; synthesis of ethylene glycol via hydroformylation of formaldehyde; synthesis of n- butanol and n-butyraldehyde by propylene formylation; synthesis of acrylic acid; homologation reaction of carboxylic acid esters with ruthenium catalysts; and synthesis of phenyl isocyanate from nitrobenzene by reductive carbonylation. 26 refs.

  17. Current status of grafts and implants in rhinoplasty: Part II. Homologous grafts and allogenic implants.

    Science.gov (United States)

    Sajjadian, Ali; Naghshineh, Nima; Rubinstein, Roee

    2010-03-01

    After reading this article, the participant should be able to: 1. Understand the challenges in restoring volume and structural integrity in rhinoplasty. 2. Identify the appropriate uses of various homologous grafts and allogenic implants in reconstruction, including: (a) freeze-dried acellular allogenic cadaveric dermis grafts, (b) irradiated cartilage grafts, (c) hydroxyapatite mineral matrix, (d) silicone implants, (e) high-density polyethylene implants, (f) polytetrafluoroethylene implants, and (g) injectable filler materials. 3. Identify the advantages and disadvantages of each of these biomaterials. 4. Understand the specific techniques that may aid in the use these grafts or implants. This review specifically addresses the use of homologous grafts and allogenic implants in rhinoplasty. It is important to stress that autologous materials remain the preferred graft material for use in rhinoplasty, owing to their high biocompatibility and low risk of infection and extrusion. However, concerns of donor-site morbidity, graft availability, and graft resorption have motivated the development and use of homologous and allogenic implants.

  18. FBH1 helicase disrupts RAD51 filaments in vitro and modulates homologous recombination in mammalian cells

    DEFF Research Database (Denmark)

    Simandlova, Jitka; Zagelbaum, Jennifer; Payne, Miranda J

    2013-01-01

    Efficient repair of DNA double strand breaks and interstrand cross-links requires the homologous recombination (HR) pathway, a potentially error-free process that utilizes a homologous sequence as a repair template. A key player in HR is RAD51, the eukaryotic ortholog of bacterial RecA protein. RAD......51 can polymerize on DNA to form a nucleoprotein filament that facilitates both the search for the homologous DNA sequences and the subsequent DNA strand invasion required to initiate HR. Because of its pivotal role in HR, RAD51 is subject to numerous positive and negative regulatory influences...... filaments on DNA through its ssDNA translocase function. Consistent with this, a mutant mouse embryonic stem cell line with a deletion in the FBH1 helicase domain fails to limit RAD51 chromatin association and shows hyper-recombination. Our data are consistent with FBH1 restraining RAD51 DNA binding under...

  19. Uptake and Persistence of Homologous and Heterologous Zooxanthellae in the Temperate Sea Anemone Cereus pedunculatus (Pennant).

    Science.gov (United States)

    Davy, S K; Lucas, I A N; Turner, J R

    1997-04-01

    The uptake and persistence of symbiotic dinoflagellates (zooxanthellae) were measured in the temperate sea anemone Cereus pedunculatus (Pennant). Aposymbiotic specimens of C. pedunculatus were inoculated with zooxanthellae freshly isolated from a range of temperate and subtropical Anthozoa. Each inoculate consisted of zooxanthellae from a single host species and was either homologous (zooxanthellae from a host of the same species as the one being inoculated) or heterologous (from a host of a different species than the one being inoculated). The densities of zooxanthellae in host tissues were determined at regular intervals. C. pedunculatus took up homologous and heterologous zooxanthellae to similar degrees, except for zooxanthellae from the temperate Anthopleura ballii, which were taken up to a lesser extent. The densities of all zooxanthellae declined between 4 hours and 4 days after uptake, indicating that zooxanthellae were expelled, digested, or both during this period. The densities of all zooxanthellae increased between 2 and 8 weeks after inoculation, indicating zooxanthella growth. Over the entire 8-week period after uptake, densities of homologous zooxanthellae were always greater than those of heterologous zooxanthellae. Between 8 and 36 weeks after infection, densities of homologous zooxanthellae declined markedly and densities of some heterologous zooxanthellae increased further, resulting in homologous and heterologous zooxanthella densities being the same at 36 weeks. These densities were the same as those in naturally infected C. pedunculatus of similar size. The results suggest that zooxanthellae from a range of host species and environments can establish symbioses with C. pedunculatus and that, over long periods under laboratory conditions, heterologous zooxanthellae may populate C. pedunculatus to the same extent as homologous zooxanthellae.

  20. Long-term use and follow-up of autologous and homologous cartilage graft in rhinoplasty

    Directory of Open Access Journals (Sweden)

    Ghasemali Khorasani

    2016-05-01

    Full Text Available Background: Cartilage grafting is used in rhinoplasty and reconstructive surgeries. Autologous rib and nasal septum cartilage (auto graft is the preferred source of graft material in rhinoplasty, however, homologous cartilage (allograft has been extensively used to correct the nasal framework in nasal deformities. Autologous cartilage graft usage is restricted with complication of operation and limiting availability of tissue for extensive deformities. Alternatively, preserved costal cartilage allograft represents a readily available and easily contoured material. The current study was a formal systematic review of complications associated with autologous versus homologous cartilage grafting in rhinoplasty patients. Methods: In this cohort retrospective study, a total of 124 patients undergone primary or revision rhinoplasty using homologous or autologus grafts with postoperative follow-up ranging from 6 to 60 months were studied. The types of grafts and complications related to the grafts were evaluated. This included evaluation for warping, infection, resorption, mobility and fracture. Results: The total complications related to the cartilage grafts were 7 cases, which included 1 warped in auto graft group, three cases of graft displacement (two in allograft group and one in auto graft group and three fractures in allograft group. No infection and resorption was recorded. Complication rate (confidence interval 0.95 in autologous and homologous group were 1.25(0.4-3.88 and 2.08(0.78-5.55 in 1000 months follow up. There was no statistically significant difference between autologous and homologous group complications. Onset of complication in autologous and homologous group were 51.23(49.27-53.19 and 58.7(54.51-62.91 month respectively (P=0.81. Conclusion: The allograft cartilage has the advantage of avoiding donor-site scar. Moreover, it provides the same benefits as autologous costal cartilage with comparable complication rate. Therefore, it

  1. Non-homologous isofunctional enzymes: a systematic analysis of alternative solutions in enzyme evolution.

    Science.gov (United States)

    Omelchenko, Marina V; Galperin, Michael Y; Wolf, Yuri I; Koonin, Eugene V

    2010-04-30

    Evolutionarily unrelated proteins that catalyze the same biochemical reactions are often referred to as analogous - as opposed to homologous - enzymes. The existence of numerous alternative, non-homologous enzyme isoforms presents an interesting evolutionary problem; it also complicates genome-based reconstruction of the metabolic pathways in a variety of organisms. In 1998, a systematic search for analogous enzymes resulted in the identification of 105 Enzyme Commission (EC) numbers that included two or more proteins without detectable sequence similarity to each other, including 34 EC nodes where proteins were known (or predicted) to have distinct structural folds, indicating independent evolutionary origins. In the past 12 years, many putative non-homologous isofunctional enzymes were identified in newly sequenced genomes. In addition, efforts in structural genomics resulted in a vastly improved structural coverage of proteomes, providing for definitive assessment of (non)homologous relationships between proteins. We report the results of a comprehensive search for non-homologous isofunctional enzymes (NISE) that yielded 185 EC nodes with two or more experimentally characterized - or predicted - structurally unrelated proteins. Of these NISE sets, only 74 were from the original 1998 list. Structural assignments of the NISE show over-representation of proteins with the TIM barrel fold and the nucleotide-binding Rossmann fold. From the functional perspective, the set of NISE is enriched in hydrolases, particularly carbohydrate hydrolases, and in enzymes involved in defense against oxidative stress. These results indicate that at least some of the non-homologous isofunctional enzymes were recruited relatively recently from enzyme families that are active against related substrates and are sufficiently flexible to accommodate changes in substrate specificity.

  2. Simulation methods supporting homologation of Electronic Stability Control in vehicle variants

    Science.gov (United States)

    Lutz, Albert; Schick, Bernhard; Holzmann, Henning; Kochem, Michael; Meyer-Tuve, Harald; Lange, Olav; Mao, Yiqin; Tosolin, Guido

    2017-10-01

    Vehicle simulation has a long tradition in the automotive industry as a powerful supplement to physical vehicle testing. In the field of Electronic Stability Control (ESC) system, the simulation process has been well established to support the ESC development and application by suppliers and Original Equipment Manufacturers (OEMs). The latest regulation of the United Nations Economic Commission for Europe UN/ECE-R 13 allows also for simulation-based homologation. This extends the usage of simulation from ESC development to homologation. This paper gives an overview of simulation methods, as well as processes and tools used for the homologation of ESC in vehicle variants. The paper first describes the generic homologation process according to the European Regulation (UN/ECE-R 13H, UN/ECE-R 13/11) and U.S. Federal Motor Vehicle Safety Standard (FMVSS 126). Subsequently the ESC system is explained as well as the generic application and release process at the supplier and OEM side. Coming up with the simulation methods, the ESC development and application process needs to be adapted for the virtual vehicles. The simulation environment, consisting of vehicle model, ESC model and simulation platform, is explained in detail with some exemplary use-cases. In the final section, examples of simulation-based ESC homologation in vehicle variants are shown for passenger cars, light trucks, heavy trucks and trailers. This paper is targeted to give a state-of-the-art account of the simulation methods supporting the homologation of ESC systems in vehicle variants. However, the described approach and the lessons learned can be used as reference in future for an extended usage of simulation-supported releases of the ESC system up to the development and release of driver assistance systems.

  3. Evolutionary origin and divergence of GnIH and its homologous peptides.

    Science.gov (United States)

    Tsutsui, Kazuyoshi; Osugi, Tomohiro

    2009-03-01

    Probing undiscovered hypothalamic neuropeptides that play important roles in the regulation of pituitary function in vertebrates is essential for the progress of neuroendocrinology. In 2000, we discovered a novel hypothalamic dodecapeptide inhibiting gonadotropin release in quail and termed it gonadotropin-inhibitory hormone (GnIH). GnIH acts on the pituitary and gonadotropin-releasing hormone (GnRH) neurons in the hypothalamus via a novel G protein-coupled receptor for GnIH to inhibit gonadal development and maintenance by decreasing gonadotropin release and synthesis. Similar findings were observed in other avian species. Thus, GnIH is a key factor controlling avian reproduction. To give our findings a broader perspective, we also found GnIH homologous peptides in the hypothalamus of other vertebrates, such as mammals, reptiles, amphibians and teleosts. GnIH and its homologs share a common C-terminal LPXRFamide (X=L or Q) motif. A mammalian GnIH homolog also inhibited gonadotropin release in mammals like the GnIH action in birds. In contrast to higher vertebrates, hypophysiotropic activities of GnIH homologs were different in lower vertebrates. To clarify the evolutionary origin of GnIH and its homologs, we further sought to identify novel LPXRFamide peptides from the brain of sea lamprey and hagfish, two extant groups of the oldest lineage of vertebrates, Agnatha. In these agnathans, LPXRFamide peptide and its cDNA were identified only from the brain of hagfish. Based on these findings over the past decade, this paper summarizes the evolutionary origin and divergence of GnIH and its homologous peptides.

  4. Unimode metamaterials exhibiting negative linear compressibility and negative thermal expansion

    International Nuclear Information System (INIS)

    Dudek, Krzysztof K; Attard, Daphne; Caruana-Gauci, Roberto; Grima, Joseph N; Wojciechowski, Krzysztof W

    2016-01-01

    Unimode metamaterials made from rotating rigid triangles are analysed mathematically for their mechanical and thermal expansion properties. It is shown that these unimode systems exhibit positive Poisson’s ratios irrespective of size, shape and angle of aperture, with the Poisson’s ratio exhibiting giant values for certain conformations. When the Poisson’s ratio in one loading direction is larger than +1, the systems were found to exhibit the anomalous property of negative linear compressibility along this direction, that is, the systems expand in this direction when hydrostatically compressed. Also discussed are the thermal expansion properties of these systems under the assumption that the units exhibit increased rotational agitation once subjected to an increase in temperature. The effect of the geometric parameters on the aforementioned thermo-mechanical properties of the system, are discussed, with the aim of identifying negative behaviour. (paper)

  5. TrayGen: Arranging objects for exhibition and packaging

    KAUST Repository

    Yang, Yongliang; Huang, Qixing

    2013-01-01

    We present a framework, called TrayGen, to generate tray designs for the exhibition and packaging of a collection of objects. Based on principles from shape perception and visual merchandising, we abstract a number of design guidelines on how

  6. "Britain at CERN" exhibition, from 14 to 17 November 2000

    CERN Multimedia

    Patrice Loïez

    2000-01-01

    H.E. Mr. Christopher Hulse, Ambassador of United Kingdom in Switzerland, CERN Director General Luciano Maiani, Sir David Wright, Chief Executive of British Trade International and Roger Cashmore, CERN Director of research visit the Britain at CERN exhibition

  7. Asian Martial Art Exhibitions at the Swiss Castle of Morges

    Directory of Open Access Journals (Sweden)

    Nicolae Gothard Bialokur

    2012-07-01

    Full Text Available This article reports on two unique cultural exhibitions (2005 and 2007 held in Morges, Switzerland. The main theme for these exhibitions was Asian martial arts with a focus on those from Japan, including presentations by notable masters in aikido, karate, judo, kyudo, iaido, kenjutsu, jodo, juttejutsu, kusarigamajutsu, naginatajutsu, tameshigiri, and kendo. On exhibit were artifacts from Morges Castle museum collections as well as numerous ancient objects borrowed specifically for these exhibitions from other Swiss museums and private collections. There was also a lecture on Japanese sword collecting and care, and presentations of Japanese dance, flower arranging (ikebana, the art of tea (châ no yu, châdo, paper folding (origami, traditional kimono dress, and detailed demonstrations on the manufacture of bladed weapons. Text and photography were arranged to record these events for this article, showing how excellent organization and cooperation can introduce high-quality martial traditions to the public.

  8. Editorial Notes: Exhibition Complex: Displaying People, Identity, and Culture

    Directory of Open Access Journals (Sweden)

    Amy Cymbala

    2014-06-01

    Full Text Available Editorial Notes on section relating to submissions from the symposium Exhibition Complex: Displaying People, Identity, and Culture held October 18-20, 2012 at the Carnegie Museum of Art, Pittsburgh, Pennsylvania.

  9. British Museum Exhibition Review: The Jericho Skull, Creating an Ancestor

    Directory of Open Access Journals (Sweden)

    Cara Hirst

    2017-03-01

    Full Text Available The temporary exhibit at the British Museum, open 15th December-19th February, and located to the right of the main entrance in the Raymond and Beverly Sackler Gallery (Room 59; is dedicated to a single Neolithic crania from Jericho, known as the Jericho Skull. This exhibit demonstrates the value of relatively recent technologies in archaeological research, highlighting the previously hidden information made possible through CT scanning and the value of these methods in both archaeological research but also in communicating archaeology in a visually stimulating manner which allows an exhibit to take a single item, and create an in depth exhibit featuring both the original material and two cranial 3D prints along with a facial reconstruction.

  10. Dutch hi-tech companies exhibit at CERN

    CERN Multimedia

    Roberto Cantoni

    2010-01-01

    Twenty-seven Dutch companies will present the state of the art of their technological developments at the industrial exhibition Holland @ CERN from 8 to 11 November. The exhibition is designed to help strengthen the ties between fundamental science and Dutch industry.   The exhibition, supported by the Dutch Ministry of Economic Affairs and organised by the Netherlands National Institute for Subatomic Physics (Nikhef), in cooperation with the Foundation for Fundamental Research on Matter (FOM), the FOM Institute for Plasma Physics Rijnhuizen, and Dutch Scientific, an association of manufacturers of scientific equipment, will be held in the Main Building from 8 to11 November. “The last Holland @ CERN exhibition took place fifteen years ago”, says Robert Klöpping from Nikhef, Dutch Industrial Liaison Officer for CERN and Purchasing Advisor for Grenoble ESRF. “This kind of event is very important for Dutch industry as it allows us to show what Dutch companies c...

  11. Exhibit celebrates five decades of women in engineering

    OpenAIRE

    Gilbert, Karen

    2007-01-01

    "Petticoats and Slide Rules," a historical exhibit on women in engineering from the Society of Women Engineers (SWE), is currently on display in the lobby of Hancock 100 and will remain at Virginia Tech through March of 2007.

  12. The Lynden Pindling Exhibit: the Man, the Dream, the Moment

    Directory of Open Access Journals (Sweden)

    Shananda Miller Hinsey

    2015-06-01

    Full Text Available The Sir Lynden O. Pindling Room at the Harry C. Moore Library and Information Centre of The College of The Bahamas contains an exhibit of over 260 items, including personal effects, gifts, gowns, photographs, speeches and publications. The items included in this special exhibit space are resources that scholars, students and the public may use to research the legacy of the former prime minister and, by extension, the history of The Bahamas.

  13. The 1997 AAAI Mobile Robot Competition and Exhibition

    OpenAIRE

    Arkin, Ronald C.

    1998-01-01

    In July 1997, the Sixth Annual Association for the Advancement of Artificial Intelligence (AAAI) Mobile Robot Competition and Exhibition was held. The competition consisted of four new events: (1) Find Life on Mars; (2) Find the Remote; (3) Home Vacuum; and (4) Hors d'Oeuvres, Anyone? The robot exhibition was the largest in AAAI history. This article presents the history, motivation, and contributions for the event.

  14. Foreign Investors Able to Establish Foreign- exclusively Exhibition Corporations

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Foreign Investors Able to Establish Foreign-exclusively Exhibition Corporations In Feb, Ministry of Commerce issued its 1st decree on temporary regulation for foreign-investing corporations; the regulation allows foreign investors to set up foreign-investing convention & exhibition corporations exclusively or through cooperation with other Chinese corporations, enterprises or organizations. With legal protection on their regulatory management and legal rights, these foreign-investing corporations are in the charge of Department of Foreign Investment Administration, Ministry of Commerce.

  15. Exhibition of Monogamy Relations between Entropic Non-contextuality Inequalities

    International Nuclear Information System (INIS)

    Zhu Feng; Zhang Wei; Huang Yi-Dong

    2017-01-01

    We exhibit the monogamy relation between two entropic non-contextuality inequalities in the scenario where compatible projectors are orthogonal. We show the monogamy relation can be exhibited by decomposing the orthogonality graph into perfect induced subgraphs. Then we find two entropic non-contextuality inequalities are monogamous while the KCBS-type non-contextuality inequalities are not if the orthogonality graphs of the observable sets are two odd cycles with two shared vertices. (paper)

  16. Homological functor of a torsion free crystallographic group of dimension five with a nonabelian point group

    Science.gov (United States)

    Ting, Tan Yee; Idrus, Nor'ashiqin Mohd.; Masri, Rohaidah; Sarmin, Nor Haniza; Hassim, Hazzirah Izzati Mat

    2014-06-01

    Torsion free crystallographic groups, called Bieberbach groups, appear as fundamental groups of compact, connected, flat Riemannian manifolds and have many interesting properties. New properties of the group can be obtained by, not limited to, exploring the groups and by computing their homological functors such as nonabelian tensor squares, the central subgroup of nonabelian tensor squares, the kernel of the mapping of nonabelian tensor squares of a group to the group and many more. In this paper, the homological functor, J(G) of a centerless torsion free crystallographic group of dimension five with a nonabelian point group which is a dihedral point group is computed using commutator calculus.

  17. Two zebrafish G2A homologs activate multiple intracellular signaling pathways in acidic environment

    Energy Technology Data Exchange (ETDEWEB)

    Ichijo, Yuta; Mochimaru, Yuta [Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki 214-8571 (Japan); Azuma, Morio [Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555 (Japan); Satou, Kazuhiro; Negishi, Jun [Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki 214-8571 (Japan); Nakakura, Takashi [Department of Anatomy, Graduate School of Medicine, Teikyo University, 2-11-1 Itabashi-Ku, Tokyo 173-8605 (Japan); Oshima, Natsuki [Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki 214-8571 (Japan); Mogi, Chihiro; Sato, Koichi [Laboratory of Signal Transduction, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512 (Japan); Matsuda, Kouhei [Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555 (Japan); Okajima, Fumikazu [Laboratory of Signal Transduction, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512 (Japan); Tomura, Hideaki, E-mail: tomurah@meiji.ac.jp [Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki 214-8571 (Japan)

    2016-01-01

    Human G2A is activated by various stimuli such as lysophosphatidylcholine (LPC), 9-hydroxyoctadecadienoic acid (9-HODE), and protons. The receptor is coupled to multiple intracellular signaling pathways, including the G{sub s}-protein/cAMP/CRE, G{sub 12/13}-protein/Rho/SRE, and G{sub q}-protein/phospholipase C/NFAT pathways. In the present study, we examined whether zebrafish G2A homologs (zG2A-a and zG2A-b) could respond to these stimuli and activate multiple intracellular signaling pathways. We also examined whether histidine residue and basic amino acid residue in the N-terminus of the homologs also play roles similar to those played by human G2A residues if the homologs sense protons. We found that the zG2A-a showed the high CRE, SRE, and NFAT activities, however, zG2A-b showed only the high SRE activity under a pH of 8.0. Extracellular acidification from pH 7.4 to 6.3 ameliorated these activities in zG2A-a-expressing cells. On the other hand, acidification ameliorated the SRE activity but not the CRE and NFAT activities in zG2A-b-expressing cells. LPC or 9-HODE did not modify any activity of either homolog. The substitution of histidine residue at the 174{sup th} position from the N-terminus of zG2A-a to asparagine residue attenuated proton-induced CRE and NFAT activities but not SRE activity. The substitution of arginine residue at the 32nd position from the N-terminus of zG2A-a to the alanine residue also attenuated its high and the proton-induced CRE and NFAT activities. On the contrary, the substitution did not attenuate SRE activity. The substitution of the arginine residue at the 10th position from the N-terminus of zG2A-b to the alanine residue also did not attenuate its high or the proton-induced SRE activity. These results indicate that zebrafish G2A homologs were activated by protons but not by LPC and 9-HODE, and the activation mechanisms of the homologs were similar to those of human G2A. - Highlights: • Zebrafish two G2A homologs are proton

  18. An HMM posterior decoder for sequence feature prediction that includes homology information

    DEFF Research Database (Denmark)

    Käll, Lukas; Krogh, Anders Stærmose; Sonnhammer, Erik L. L.

    2005-01-01

    Motivation: When predicting sequence features like transmembrane topology, signal peptides, coil-coil structures, protein secondary structure or genes, extra support can be gained from homologs. Results: We present here a general hidden Markov model (HMM) decoding algorithm that combines probabil......Motivation: When predicting sequence features like transmembrane topology, signal peptides, coil-coil structures, protein secondary structure or genes, extra support can be gained from homologs. Results: We present here a general hidden Markov model (HMM) decoding algorithm that combines......://phobius.cgb.ki.se/poly.html . An implementation of the algorithm is available on request from the authors....

  19. Activation barriers for series of exothermic homologous reactions. VI. Reactions of lanthanide and transition metal atoms.

    Science.gov (United States)

    Blue, Alan S.; Fontijn, Arthur

    2001-09-01

    Semiempirical configuration interaction (SECI) theory to predict activation barriers, E, as given by k(T)=ATn exp(-E(RT), has been applied to homologous series of lanthanide (LN) and transition metal (TM) atom oxidation reactions. This was achieved by considering as homologous series reactions of elements differing only by the number of electrons in one subshell. Comparison between SECI and experimental results leads to an average deviation for the LN+N2O reactions of 0.66 kJ mol-1, and up to 5.5 kJ mol-1 for other series. Thirty-one activation barriers are reported.

  20. The mechanism of non-homologous end-joining: a synopsis of synapsis.

    Science.gov (United States)

    Weterings, Eric; van Gent, Dik C

    2004-11-02

    Repair of DNA double-strand breaks (DSBs) by non-homologous end-joining (NHEJ) is required for resistance to genotoxic agents, such as ionizing radiation, but also for proper development of the vertebrate immune system. Much progress has been made in identifying the factors that are involved in this repair pathway. We are now entering the phase in which we begin to understand basic concepts of the reaction mechanism and regulation of non-homologous end-joining. This review concentrates on novel insights into damage recognition and subsequent tethering, processing and joining of DNA ends.

  1. OCCURRENCE OF SMALL HOMOLOGOUS AND COMPLEMENTARY FRAGMENTS IN HUMAN VIRUS GENOMES AND THEIR POSSIBLE ROLE

    Directory of Open Access Journals (Sweden)

    E. P. Kharchenko

    2017-01-01

    Full Text Available With computer analysis occurrence of small homologous and complementary fragments (21 nucleotides in length has been studied in genomes of 14 human viruses causing most dangerous infections. The sample includes viruses with (+ and (– single stranded RNA and DNA-containing hepatitis A virus. Analysis of occurrence of homologous sequences has shown the existence two extreme situations. On the one hand, the same virus contains homologous sequences to almost all other viruses (for example, Ebola virus, severe acute respiratory syndrome-related coronavirus, and mumps virus, and numerous homologous sequences to the same other virus (especially in severe acute respiratory syndrome-related coronavirus to Dengue virus and in Ebola virus to poliovirus. On the other hand, there are rare occurrence and not numerous homologous sequences in genomes of other viruses (rubella virus, hepatitis A virus, and hepatitis B virus. Similar situation exists for occurrence of complementary sequences. Rubella virus, the genome of which has the high content of guanine and cytosine, has no complementary sequences to almost all other viruses. Most viruses have moderate level of occurrence for homologous and complementary sequences. Autocomplementary sequences are numerous in most viruses and one may suggest that the genome of single stranded RNA viruses has branched secondary structure. In addition to possible role in recombination among strains autocomplementary sequences could be regulators of translation rate of virus proteins and determine its optimal proportion in virion assembly with genome and mRNA folding. Occurrence of small homologous and complementary sequences in RNA- and DNA-containing viruses may be the result of multiple recombinations in the past and the present and determine their adaptation and variability. Recombination may take place in coinfection of human and/or common hosts. Inclusion of homologous and complementary sequences into genome could not

  2. Evaluating Education and Science in the KSC Visitor Complex Exhibits

    Science.gov (United States)

    Erickson, Lance K.

    2000-01-01

    The continuing development of exhibits at the Kennedy Space Center's Visitor Complex is an excellent opportunity for NASA personnel to promote science and provide insight into NASA programs and projects for the approximately 3 million visitors that come to KSC annually. Stated goals for the Visitor Complex, in fact, emphasize science awareness and recommend broadening the appeal of the displays and exhibits for all age groups. To this end, this summer project seeks to evaluate the science content of planned exhibits/displays in relation to these developing opportunities and identify specific areas for enhancement of existing or planned exhibits and displays. To help expand the educational and science content within the developing exhibits at the Visitor Complex, this project was structured to implement the goals of the Visitor Center Director. To accomplish this, the exhibits and displays planned for completion within the year underwent review and evaluation for science content and educational direction. Planning emphasis for the individual displays was directed at combining the elements of effective education with fundamental scientific integrity, within an appealing format.

  3. Exhibits Recognition System for Combining Online Services and Offline Services

    Science.gov (United States)

    Ma, He; Liu, Jianbo; Zhang, Yuan; Wu, Xiaoyu

    2017-10-01

    In order to achieve a more convenient and accurate digital museum navigation, we have developed a real-time and online-to-offline museum exhibits recognition system using image recognition method based on deep learning. In this paper, the client and server of the system are separated and connected through the HTTP. Firstly, by using the client app in the Android mobile phone, the user can take pictures and upload them to the server. Secondly, the features of the picture are extracted using the deep learning network in the server. With the help of the features, the pictures user uploaded are classified with a well-trained SVM. Finally, the classification results are sent to the client and the detailed exhibition’s introduction corresponding to the classification results are shown in the client app. Experimental results demonstrate that the recognition accuracy is close to 100% and the computing time from the image uploading to the exhibit information show is less than 1S. By means of exhibition image recognition algorithm, our implemented exhibits recognition system can combine online detailed exhibition information to the user in the offline exhibition hall so as to achieve better digital navigation.

  4. Designing museum exhibits that facilitate visitor reflection and discussion

    DEFF Research Database (Denmark)

    Skydsgaard, Morten Arnika; Andersen, Hanne Møller; King, Heather

    2016-01-01

    This paper explores how four design principles (curiosity, challenge, narratives and participation) facilitate reflection and discussion among young visitors in the issues-based exhibition Dear, Difficult Body. The investigation is based on a mixed-method approach combining questionnaire and inte......This paper explores how four design principles (curiosity, challenge, narratives and participation) facilitate reflection and discussion among young visitors in the issues-based exhibition Dear, Difficult Body. The investigation is based on a mixed-method approach combining questionnaire...... and interview data. The implementation of design principles resulted in a variety of exhibits which variously prompted reflection and discussion on the part of visitors. Exhibits with narratives, for example, here defined as both personal and expert narratives, were found to be effective in facilitating...... personal reflection but also prompted discussion. Participation, defined as including both physical interaction with exhibits, and dialogic interaction between visitors, facilitated the sharing of ideas and feelings between visitors. Exhibits with elements of curiosity and challenge were found to attract...

  5. A phenomenological investigation of science center exhibition developers' expertise development

    Science.gov (United States)

    Young, Denise L.

    The purpose of this study was to examine the exhibition developer role in the context of United States (U.S.) science centers, and more specifically, to investigate the way science center exhibition developers build their professional expertise. This research investigated how successfully practicing exhibition developers described their current practices, how they learned to be exhibition developers, and what factors were the most important to the developers in building their professional expertise. Qualitative data was gathered from 10 currently practicing exhibition developers from three science centers: the Exploratorium, San Francisco, California; the Field Museum, Chicago, Illinois; and the Science Museum of Minnesota, St. Paul, Minnesota. In-depth, semistructured interviews were used to collect the data. The study embraced aspects of the phenomenological tradition and sought to derive a holistic understanding of the position and how expertise was built for it. The data were methodically coded and organized into themes prior to analysis. The data analysis found that the position consisted of numerous and varied activities, but the developers' primary roles were advocating for the visitor, storytelling, and mediating information and ideas. They conducted these activities in the context of a team and relied on an established exhibition planning process to guide their work. Developers described a process of learning exhibition development that was experiential in nature. Learning through daily practice was key, though they also consulted with mentors and relied on visitor studies to gauge the effectiveness of their work. They were adept at integrating prior knowledge gained from many aspects of their lives into their practice. The developers described several internal factors that contributed to their expertise development including the desire to help others, a natural curiosity about the world, a commitment to learning, and the ability to accept critique. They

  6. Water deficit modulates gene expression in growing zones of soybean seedlings. Analysis of differentially expressed cDNAs, a new beta-tubulin gene, and expression of genes encoding cell wall proteins.

    Science.gov (United States)

    Creelman, R A; Mullet, J E

    1991-10-01

    Transfer of soybean seedlings to low-water-potential vermiculite (psi w = -0.3 MPa) results in a reversible decrease in hypocotyl growth and modulation of several polysomal mRNAs (Plant Physiol 92: 205-214). We report here the isolation of two cDNA clones (pGE16 and pGE95) which correspond to genes whose mRNA levels are increased, and one cDNA clone (pGE23) which corresponds to a gene whose mRNA level is decreased in the hypocotyl zone of cell elongation by water deficit. In well-watered seedlings mRNAs hybridizing to pGE16 and pGE95 are most abundant in mature regions of the seedling, but in water-deficient seedlings mRNA levels are reduced in mature regions and enhanced in elongating regions. RNA corresponding to soybean proline-rich protein 1 (sbPRP1) shows a similar tissue distribution and response to water deficit. In contrast, in well-watered seedlings, the gene corresponding to pGE23 was highly expressed in the hypocotyl and root growing zones. Transfer of seedlings to low-water-potential vermiculite caused a rapid decrease in mRNA hybridizing to pGE23. Sequence analysis revealed that pGE23 has high homology with beta-tubulin. Water deficit also reduced the level of mRNA hybridizing to JCW1, an auxin-modulated gene, although with different kinetics. Furthermore, mRNA encoding actin, glycine-rich proteins (GRPs), and hydroxyproline-rich glycoproteins (HRGPs) were down-regulated in the hypocotyl zone of elongation of seedlings exposed to water deficit. No effect of water deficit was observed on the expression of chalcone synthase. Decreased expression of beta-tubulin, actin, JCW1, HRGP and GRP and increased expression of sbPRP1, pGE95 and pGE16 in the hypocotyl zone of cell elongation could participate in the reversible growth inhibition observed in water-deficient soybean seedlings.

  7. A Salmonella typhimurium ghost vaccine induces cytokine expression in vitro and immune responses in vivo and protects rats against homologous and heterologous challenges.

    Directory of Open Access Journals (Sweden)

    Nagarajan Vinod

    Full Text Available Salmonella enteritidis and Salmonella typhimurium are important food-borne bacterial pathogens, which are responsible for diarrhea and gastroenteritis in humans and animals. In this study, S. typhimurium bacterial ghost (STG was generated based on minimum inhibitory concentration (MIC of sodium hydroxide (NaOH. Experimental studies performed using in vitro and in vivo experimental model systems to characterize effects of STG as a vaccine candidate. When compared with murine macrophages (RAW 264.7 exposed to PBS buffer (98.1%, the macrophages exposed to formalin-killed inactivated cells (FKC, live wild-type bacterial cells and NaOH-induced STG at 1 × 108 CFU/mL showed 85.6%, 66.5% and 84.6% cell viability, respectively. It suggests that STG significantly reduces the cytotoxic effect of wild-type bacterial cells. Furthermore, STG is an excellent inducer for mRNAs of pro-inflammatory cytokine (TNF-α, IL-1β and factor (iNOS, anti-inflammatory cytokine (IL-10 and dual activities (IL-6 in the stimulated macrophage cells. In vivo, STG vaccine induced humoral and cellular immune responses and protection against homologous and heterologous challenges in rats. Furthermore, the immunogenicity and protective efficacy of STG vaccine were compared with those of FKC and non-vaccinated PBS control groups. The vaccinated rats from STG group exhibited higher levels of serum IgG antibody responses, serum bactericidal antibodies, and CD4+ and CD8+ T-cell populations than those of the FKC and PBS control groups. Most importantly, after challenge with homologous and heterologous strains, the bacterial loads in the STG group were markedly lower than the FKC and PBS control groups. In conclusion, these findings suggest that the STG vaccine induces protective immunity against homologous and heterologous challenges.

  8. Phosphatase and tensin homolog-β-catenin signaling modulates regulatory T cells and inflammatory responses in mouse liver ischemia/reperfusion injury.

    Science.gov (United States)

    Zhu, Qiang; Li, Changyong; Wang, Kunpeng; Yue, Shi; Jiang, Longfeng; Ke, Michael; Busuttil, Ronald W; Kupiec-Weglinski, Jerzy W; Zhang, Feng; Lu, Ling; Ke, Bibo

    2017-06-01

    The phosphatase and tensin homolog (PTEN) deleted on chromosome 10 plays an important role in regulating T cell activation during inflammatory response. Activation of β-catenin is crucial for maintaining immune homeostasis. This study investigates the functional roles and molecular mechanisms by which PTEN-β-catenin signaling promotes regulatory T cell (Treg) induction in a mouse model of liver ischemia/reperfusion injury (IRI). We found that mice with myeloid-specific phosphatase and tensin homolog knockout (PTEN M-KO ) exhibited reduced liver damage as evidenced by decreased levels of serum alanine aminotransferase, intrahepatic macrophage trafficking, and proinflammatory mediators compared with the PTEN-proficient (floxed phosphatase and tensin homolog [PTEN FL/FL ]) controls. Disruption of myeloid PTEN-activated b-catenin promoted peroxisome proliferator-activated receptor gamma (PPARγ)-mediated Jagged-1/Notch signaling and induced forkhead box P3 (FOXP3)1 Tregs while inhibiting T helper 17 cells. However, blocking of Notch signaling by inhibiting γ-secretase reversed myeloid PTEN deficiency-mediated protection in ischemia/reperfusion-triggered liver inflammation with reduced FOXP3 + and increased retinoid A receptor-related orphan receptor gamma t-mediated interleukin 17A expression in ischemic livers. Moreover, knockdown of β-catenin or PPARγ in PTEN-deficient macrophages inhibited Jagged-1/Notch activation and reduced FOXP3 + Treg induction, leading to increased proinflammatory mediators in macrophage/T cell cocultures. In conclusion, our findings demonstrate that PTEN-β-catenin signaling is a novel regulator involved in modulating Treg development and provides a potential therapeutic target in liver IRI. Liver Transplantation 23 813-825 2017 AASLD. © 2017 by the American Association for the Study of Liver Diseases.

  9. Lack of mitochondrial MutS homolog 1 in Toxoplasma gondii disrupts maintenance and fidelity of mitochondrial DNA and reveals metabolic plasticity.

    Directory of Open Access Journals (Sweden)

    Tamila Garbuz

    Full Text Available The importance of maintaining the fidelity of the mitochondrial genome is underscored by the presence of various repair pathways within this organelle. Presumably, the repair of mitochondrial DNA would be of particular importance in organisms that possess only a single mitochondrion, like the human pathogens Plasmodium falciparum and Toxoplasma gondii. Understanding the machinery that maintains mitochondrial DNA in these parasites is of particular relevance, as mitochondrial function is a validated and effective target for anti-parasitic drugs. We previously determined that the Toxoplasma MutS homolog TgMSH1 localizes to the mitochondrion. MutS homologs are key components of the nuclear mismatch repair system in mammalian cells, and both yeast and plants possess MutS homologs that localize to the mitochondria where they regulate DNA stability. Here we show that the lack of TgMSH1 results in accumulation of single nucleotide variations in mitochondrial DNA and a reduction in mitochondrial DNA content. Additionally, parasites lacking TgMSH1 function can survive treatment with the cytochrome b inhibitor atovaquone. While the Tgmsh1 knockout strain has several missense mutations in cytochrome b, none affect amino acids known to be determinants of atovaquone sensitivity and atovaquone is still able to inhibit electron transport in the Tgmsh1 mutants. Furthermore, culture of Tgmsh1 mutant in the presence atovaquone leads to parasites with enhanced atovaquone resistance and complete shutdown of respiration. Thus, parasites lacking TgMSH1 overcome the disruption of mitochondrial DNA by adapting their physiology allowing them to forgo the need for oxidative phosphorylation. Consistent with this idea, the Tgmsh1 mutant is resistant to mitochondrial inhibitors with diverse targets and exhibits reduced ability to grow in the absence of glucose. This work shows TgMSH1 as critical for the maintenance and fidelity of the mitochondrial DNA in Toxoplasma

  10. Characterization of the major formamidopyrimidine-DNA glycosylase homolog in Mycobacterium tuberculosis and its linkage to variable tandem repeats.

    Science.gov (United States)

    Olsen, Ingrid; Balasingham, Seetha V; Davidsen, Tonje; Debebe, Ephrem; Rødland, Einar A; van Soolingen, Dick; Kremer, Kristin; Alseth, Ingrun; Tønjum, Tone

    2009-07-01

    The ability to repair DNA damage is likely to play an important role in the survival of facultative intracellular parasites because they are exposed to high levels of reactive oxygen species and nitrogen intermediates inside phagocytes. Correcting oxidative damage in purines and pyrimidines is the primary function of the enzymes formamidopyrimidine (faPy)-DNA glycosylase (Fpg) and endonuclease VIII (Nei) of the base excision repair pathway, respectively. Four gene homologs, belonging to the fpg/nei family, have been identified in Mycobacterium tuberculosis H37Rv. The recombinant protein encoded by M. tuberculosis Rv2924c, termed Mtb-Fpg1, was overexpressed, purified and biochemically characterized. The enzyme removed faPy and 5-hydroxycytosine lesions, as well as 8-oxo-7,8-dihydroguanine (8oxoG) opposite to C, T and G. Mtb-Fpg1 thus exhibited substrate specificities typical for Fpg enzymes. Although Mtb-fpg1 showed nearly complete nucleotide sequence conservation in 32 M. tuberculosis isolates, the region upstream of Mtb-fpg1 in these strains contained tandem repeat motifs of variable length. A relationship between repeat length and Mtb-fpg1 expression level was demonstrated in M. tuberculosis strains, indicating that an increased length of the tandem repeats positively influenced the expression levels of Mtb-fpg1. This is the first example of such a tandem repeat region of variable length being linked to the expression level of a bacterial gene.

  11. Promotion of Homologous Recombination and Genomic Stability byRAD51AP1 via RAD51 Recombinase Enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Wiese, Claudia; Dray, Eloise; Groesser, Torsten; San Filippo,Joseph; Shi, Idina; Collins, David W.; Tsai, Miaw-Sheue; Williams,Gareth; Rydberg, Bjorn; Sung, Patrick; Schild, David

    2007-04-11

    Homologous recombination (HR) repairs chromosome damage and is indispensable for tumor suppression in humans. RAD51 mediates the DNA strand pairing step in HR. RAD51AP1 (RAD51 Associated Protein 1) is a RAD51-interacting protein whose function has remained elusive. Knockdown of RAD51AP1 in human cells by RNA interference engenders sensitivity to different types of genotoxic stress. Moreover, RAD51AP1-depleted cells are impaired for the recombinational repair of a DNA double-strand break and exhibit chromatid breaks both spontaneously and upon DNA damaging treatment. Purified RAD51AP1 binds dsDNA and RAD51, and it greatly stimulates the RAD51-mediated D-loop reaction. Biochemical and cytological results show that RAD51AP1 functions at a step subsequent to the assembly of the RAD51-ssDNA nucleoprotein filament. Our findings provide the first evidence that RAD51AP1 helps maintain genomic integrity via RAD51 recombinase enhancement.

  12. The Drosophila KIF1A homolog unc-104 is important for site-specific active zone maturation

    Directory of Open Access Journals (Sweden)

    Yao V. Zhang

    2016-09-01

    Full Text Available Abstract Mutations in the kinesin-3 family member KIF1A have been associated with hereditary spastic paraplegia, hereditary sensory and autonomic neuropathy type 2 and intellectual disability. Both autosomal recessive and autosomal dominant forms of inheritance have been reported. Loss of KIF1A or its homolog unc-104 causes early postnatal or embryonic lethality in mice and Drosophila, respectively. In this study we use a previously described hypomorphic allele of unc-104, unc-104bris, to investigate the impact of partial loss-of-function of kinesin-3 function on active zone formation at the Drosophila neuromuscular junction. unc-104bris mutants exhibit synaptic defects where a subset of synapses at the neuromuscular junction lack the key active zone organizer protein Bruchpilot. Modulating synaptic Bruchpilot levels by ectopic overexpression or RNAi-mediated knockdown suggests that the loss of active zone components such as Ca2+ channel and Liprin-α from these synapses is caused by impaired kinesin-3 transport rather than due to the absence of Bruchpilot at these synapses. In addition to defects in active zone maturation, unc-104bris mutants display impaired transport of dense core vesicles and synaptic vesicle associated proteins, among which Rab3 has been shown to regulate the distribution of Bruchpilot to active zones. Overexpression of Rab3 partially ameliorates synaptic phenotypes of unc-104bris neuromuscular junction, suggesting that lack of presynaptic Rab3 may contribute to defects in synapse maturation.

  13. Reference Genome-Directed Resolution of Homologous and Homeologous Relationships within and between Different Oat Linkage Maps

    Directory of Open Access Journals (Sweden)

    Juan J. Gutierrez-Gonzalez

    2011-11-01

    Full Text Available Genome research on oat ( L. has received less attention than wheat ( L. and barley ( L. because it is a less prominent component of the human food system. To assess the potential of the model grass (L P. Beauv. as a surrogate for oat genome research, the whole genome sequence (WGS of was employed for comparative analysis with oat genetic linkage maps. Sequences of mapped molecular markers from one diploid spp. and two hexaploid oat maps were aligned to the WGS to infer syntenic relationships. Diploid and exhibit a high degree of synteny with 18 syntenic blocks covering 87% of the oat genome, which permitted postulation of an ancestral spp. chromosome structure. Synteny between oat and was also prevalent, with 50 syntenic blocks covering 76.6% of the ‘Kanota’ × ‘Ogle’ linkage map. Coalignment of diploid and hexaploid maps to helped resolve homeologous relationships between different oat linkage groups but also revealed many major rearrangements in oat subgenomes. Extending the analysis to a second oat linkage map (Ogle × ‘TAM O-301’ allowed identification of several putative homologous linkage groups across the two oat populations. These results indicate that the genome sequence will be a useful resource to assist genetics and genomics research in oat. The analytical strategy employed here should be applicable for genome research in other temperate grass crops with modest amounts of genomic data.

  14. Homologous recombination contributes to the repair of DNA double-strand breaks induced by high-energy iron ions

    Energy Technology Data Exchange (ETDEWEB)

    Zafar, Faria; Seidler, Sara B.; Kronenberg, Amy; Schild, David; Wiese, Claudia

    2010-06-29

    To test the contribution of homologous recombinational repair (HRR) in repairing DNA damaged sites induced by high-energy iron ions, we used: (1) HRR-deficient rodent cells carrying a deletion in the RAD51D gene and (2) syngeneic human cells impaired for HRR by RAD51D or RAD51 knockdown using RNA interference. We show that in response to iron ions, HRR contributes to cell survival in rodent cells, and that HRR-deficiency abrogates RAD51 foci formation. Complementation of the HRR defect by human RAD51D rescues both enhanced cytotoxicity and RAD51 foci formation. For human cells irradiated with iron ions, cell survival is decreased, and, in p53 mutant cells, the levels of mutagenesis are increased when HRR is impaired. Human cells synchronized in S phase exhibit more pronounced resistance to iron ions as compared with cells in G1 phase, and this increase in radioresistance is diminished by RAD51 knockdown. These results implicate a role for RAD51-mediated DNA repair (i.e. HRR) in removing a fraction of clustered lesions induced by charged particle irradiation. Our results are the first to directly show the requirement for an intact HRR pathway in human cells in ensuring DNA repair and cell survival in response to high-energy high LET radiation.

  15. Reconstruction of a Large-scale Pre-flare Coronal Current Sheet Associated with a Homologous X-shaped Flare

    Science.gov (United States)

    Jiang, Chaowei; Yan, Xiaoli; Feng, Xueshang; Duan, Aiying; Hu, Qiang; Zuo, Pingbing; Wang, Yi

    2017-11-01

    As a fundamental magnetic structure in the solar corona, electric current sheets (CSs) can form either prior to or during a solar flare, and they are essential for magnetic energy dissipation in the solar corona because they enable magnetic reconnection. However, the static reconstruction of a CS is rare, possibly due to limitations that are inherent in the available coronal field extrapolation codes. Here we present the reconstruction of a large-scale pre-flare CS in solar active region 11967 using an MHD-relaxation model constrained by the SDO/HMI vector magnetogram. The CS is associated with a set of peculiar homologous flares that exhibit unique X-shaped ribbons and loops occurring in a quadrupolar magnetic configuration.This is evidenced by an ’X’ shape, formed from the field lines traced from the CS to the photosphere. This nearly reproduces the shape of the observed flare ribbons, suggesting that the flare is a product of the dissipation of the CS via reconnection. The CS forms in a hyperbolic flux tube, which is an intersection of two quasi-separatrix layers. The recurrence of the X-shaped flares might be attributed to the repetitive formation and dissipation of the CS, as driven by the photospheric footpoint motions. These results demonstrate the power of a data-constrained MHD model in reproducing a CS in the corona as well as providing insight into the magnetic mechanism of solar flares.

  16. A Helicobacter pylori Homolog of Eukaryotic Flotillin Is Involved in Cholesterol Accumulation, Epithelial Cell Responses and Host Colonization

    Directory of Open Access Journals (Sweden)

    Melanie L. Hutton

    2017-06-01

    Full Text Available The human pathogen Helicobacter pylori acquires cholesterol from membrane raft domains in eukaryotic cells, commonly known as “lipid rafts.” Incorporation of this cholesterol into the H. pylori cell membrane allows the bacterium to avoid clearance by the host immune system and to resist the effects of antibiotics and antimicrobial peptides. The presence of cholesterol in H. pylori bacteria suggested that this pathogen may have cholesterol-enriched domains within its membrane. Consistent with this suggestion, we identified a hypothetical H. pylori protein (HP0248 with homology to the flotillin proteins normally found in the cholesterol-enriched domains of eukaryotic cells. As shown for eukaryotic flotillin proteins, HP0248 was detected in detergent-resistant membrane fractions of H. pylori. Importantly, H. pylori HP0248 mutants contained lower levels of cholesterol than wild-type bacteria (P < 0.01. HP0248 mutant bacteria also exhibited defects in type IV secretion functions, as indicated by reduced IL-8 responses and CagA translocation in epithelial cells (P < 0.05, and were less able to establish a chronic infection in mice than wild-type bacteria (P < 0.05. Thus, we have identified an H. pylori flotillin protein and shown its importance for bacterial virulence. Taken together, the data demonstrate important roles for H. pylori flotillin in host-pathogen interactions. We propose that H. pylori flotillin may be required for the organization of virulence proteins into membrane raft-like structures in this pathogen.

  17. Members of the amylovora group of Erwinia are cellulolytic and possess genes homologous to the type II secretion pathway.

    Science.gov (United States)

    Riekki, R; Palomäki, T; Virtaharju, O; Kokko, H; Romantschuk, M; Saarilahti, H T

    2000-07-01

    A cellulase-producing clone was isolated from a genomic library of the Erwinia rhapontici (Millard) Burkholder strain NCPPB2989. The corresponding gene, named celA, encodes an endoglucanase (EC 3.2.1.4) with the extremely low pH optimum of 3.4 and a temperature optimum between 40 and 50 degrees C. A single ORF of 999 nt was found to be responsible for the Cel activity. The corresponding protein, named CelA, showed 67% identity to the endoglucanase Y of E. chrysanthemi and 51.5% identity to the endoglucanase of Cellulomonas uda, and thus belongs to the glycosyl hydrolase family 8. The celA gene, or its homologue, was found to be present in all E. rhapontici isolates analysed, in E. chrysanthemi, and in E. amylovora. The presence of plant cell wall-degrading enzymes in the amylovora group of Erwinia spp. had not previously been established. Furthermore, the DNA of both E. rhapontici and E. amylovora was found to exhibit homology to genes encoding the type II (GSP) secretion pathway, which is known to be responsible for extracellular targeting of cellulases and pectinases in Erwinia spp. that cause soft rotting, such as E. carotovora and E. chrysanthemi. Secretion of the CelA protein by E. rhapontici could not be verified. However, the CelA protein itself was found to include the information necessary for heterologous secretion by E. chrysanthemi.

  18. ANGUSTIFOLIA, a Plant Homolog of CtBP/BARS Localizes to Stress Granules and Regulates Their Formation

    Directory of Open Access Journals (Sweden)

    Hemal Bhasin

    2017-06-01

    Full Text Available The ANGUSTIFOLIA (AN gene in Arabidopsis is important for a plethora of morphological phenotypes. Recently, AN was also reported to be involved in responses to biotic and abiotic stresses. It encodes a homolog of the animal C-terminal binding proteins (CtBPs. In contrast to animal CtBPs, AN does not appear to function as a transcriptional co-repressor and instead functions outside nucleus where it might be involved in Golgi-associated membrane trafficking. In this study, we report a novel and unexplored role of AN as a component of stress granules (SGs. Interaction studies identified several RNA binding proteins that are associated with AN. AN co-localizes with several messenger ribonucleoprotein granule markers to SGs in a stress dependent manner. an mutants exhibit an altered SG formation. We provide evidence that the NAD(H binding domain of AN is relevant in this context as proteins carrying mutations in this domain localize to a much higher degree to SGs and strongly reduce AN dimerization and its interaction with one interactor but not the others. Finally, we show that AN is a negative regulator of salt and osmotic stress responses in Arabidopsis suggesting a functional relevance in SGs.

  19. Frontoparietal regions may become hypoactive after intermittent theta burst stimulation over the contralateral homologous cortex in humans.

    Science.gov (United States)

    He, Xiaofei; Lan, Yue; Xu, Guangqing; Mao, Yurong; Chen, Zhenghong; Huang, Dongfeng; Pei, Zhong

    2013-12-01

    Brain injury to the dorsal frontoparietal networks, including the posterior parietal cortex (PPC) and dorsolateral prefrontal cortex (DLPFC), commonly cause spatial neglect. However, the interaction of these different regions in spatial attention is unclear. The aim of the present study was to investigate whether hyperexcitable neural networks can cause an abnormal interhemispheric inhibition. The Attention Network Test was used to test subjects following intermittent theta burst stimulation (iTBS) to the left or right frontoparietal networks. During the Attention Network Test task, all subjects tolerated each conditioning iTBS without any obvious iTBS-related side effects. Subjects receiving real-right-PPC iTBS showed significant enhancement in both alerting and orienting efficiency compared with those receiving either sham-right-PPC iTBS or real-left-PPC iTBS. Moreover, subjects exposed to the real-right-DLPFC iTBS exhibited significant improvement in both alerting and executive control efficiency, compared with those exposed to either the sham-right-DLPFC or real-left-DLPFC conditioning. Interestingly, compared with subjects exposed to the sham-left-PPC stimuli, subjects exposed to the real-left-PPC iTBS had a significant deficit in the orienting index. The present study indicates that iTBS over the contralateral homologous cortex may induce the hypoactivity of the right PPC through interhemispheric competition in spatial orienting attention.

  20. Frequency of intrachromosomal homologous recombination induced by UV radiation in normally repairing and excision repair-deficient human cells

    International Nuclear Information System (INIS)

    Tsujimura, T.; Maher, V.M.; McCormick, J.J.; Godwin, A.R.; Liskay, R.M.

    1990-01-01

    To investigate the role of DNA damage and nucleotide excision repair in intrachromosomal homologous recombination, a plasmid containing duplicated copies of the gene coding for hygromycin resistance was introduced into the genome of a repair-proficient human cell line, KMST-6, and two repair-deficient lines, XP2OS(SV) from xeroderma pigmentosum complementation group A and XP2YO(SV) from complementation group F. Neither hygromycin-resistance gene codes for a functional enzyme because each contains an insertion/deletion mutation at a unique site, but recombination between the two defective genes can yield hygromycin-resistant cells. The rates of spontaneous recombination in normal and xeroderma pigmentosum cell strains containing the recombination substrate were found to be similar. The frequency of UV-induced recombination was determined for three of these cell strains. At low doses, the group A cell strain and the group F cell strain showed a significant increase in frequency of recombinants. The repair-proficient cell strain required 10-to 20-fold higher doses of UV to exhibit comparable increases in frequency of recombinants. These results suggest that unexcised DNA damage, rather than the excision repair process per se, stimulates such recombination

  1. Human Leucocyte Antigen-G (HLA-G and Its Murine Functional Homolog Qa2 in the Trypanosoma cruzi Infection

    Directory of Open Access Journals (Sweden)

    Fabrício C. Dias

    2015-01-01

    Full Text Available Genetic susceptibility factors, parasite strain, and an adequate modulation of the immune system seem to be crucial for disease progression after Trypanosoma cruzi infection. HLA-G and its murine functional homolog Qa2 have well-recognized immunomodulatory properties. We evaluated the HLA-G 3′ untranslated region (3′UTR polymorphic sites (associated with mRNA stability and target for microRNA binding and HLA-G tissue expression (heart, colon, and esophagus in patients presenting Chagas disease, stratified according to the major clinical variants. Further, we investigated the transcriptional levels of Qa2 and other pro- and anti-inflammatory genes in affected mouse tissues during T. cruzi experimental acute and early chronic infection induced by the CL strain. Chagas disease patients exhibited differential HLA-G 3′UTR susceptibility allele/genotype/haplotype patterns, according to the major clinical variant (digestive/cardiac/mixed/indeterminate. HLA-G constitutive expression on cardiac muscle and colonic cells was decreased in Chagasic tissues; however, no difference was observed for Chagasic and non-Chagasic esophagus tissues. The transcriptional levels of Qa2 and other anti and proinflammatory (CTLA-4, PDCD1, IL-10, INF-γ, and NOS-2 genes were induced only during the acute T. cruzi infection in BALB/c and C57BL/6 mice. We present several lines of evidence indicating the role of immunomodulatory genes and molecules in human and experimental T. cruzi infection.

  2. Integrative analysis of genomic alterations in triple-negative breast cancer in association with homologous recombination deficiency.

    Directory of Open Access Journals (Sweden)

    Masahito Kawazu

    2017-06-01

    Full Text Available Triple-negative breast cancer (TNBC cells do not express estrogen receptors, progesterone receptors, or human epidermal growth factor receptor 2. Currently, apart from poly ADP-ribose polymerase inhibitors, there are few effective therapeutic options for this type of cancer. Here, we present comprehensive characterization of the genetic alterations in TNBC performed by high coverage whole genome sequencing together with transcriptome and whole exome sequencing. Silencing of the BRCA1 gene impaired the homologous recombination pathway in a subset of TNBCs, which exhibited similar phenotypes to tumors with BRCA1 mutations; they harbored many structural variations (SVs with relative enrichment for tandem duplication. Clonal analysis suggested that TP53 mutations and methylation of CpG dinucleotides in the BRCA1 promoter were early events of carcinogenesis. SVs were associated with driver oncogenic events such as amplification of MYC, NOTCH2, or NOTCH3 and affected tumor suppressor genes including RB1, PTEN, and KMT2C. Furthermore, we identified putative TGFA enhancer regions. Recurrent SVs that affected the TGFA enhancer region led to enhanced expression of the TGFA oncogene that encodes one of the high affinity ligands for epidermal growth factor receptor. We also identified a variety of oncogenes that could transform 3T3 mouse fibroblasts, suggesting that individual TNBC tumors may undergo a unique driver event that can be targetable. Thus, we revealed several features of TNBC with clinically important implications.

  3. Homologous recombination contributes to the repair of DNA double-strand breaks induced by high-energy iron ions

    International Nuclear Information System (INIS)

    Zafar, Faria; Seidler, Sara B.; Kronenberg, Amy; Schild, David; Wiese, Claudia

    2010-01-01

    To test the contribution of homologous recombinational repair (HRR) in repairing DNA damaged sites induced by high-energy iron ions, we used: (1) HRR-deficient rodent cells carrying a deletion in the RAD51D gene and (2) syngeneic human cells impaired for HRR by RAD51D or RAD51 knockdown using RNA interference. We show that in response to iron ions, HRR contributes to cell survival in rodent cells, and that HRR-deficiency abrogates RAD51 foci formation. Complementation of the HRR defect by human RAD51D rescues both enhanced cytotoxicity and RAD51 foci formation. For human cells irradiated with iron ions, cell survival is decreased, and, in p53 mutant cells, the levels of mutagenesis are increased when HRR is impaired. Human cells synchronized in S phase exhibit more pronounced resistance to iron ions as compared with cells in G1 phase, and this increase in radioresistance is diminished by RAD51 knockdown. These results implicate a role for RAD51-mediated DNA repair (i.e. HRR) in removing a fraction of clustered lesions induced by charged particle irradiation. Our results are the first to directly show the requirement for an intact HRR pathway in human cells in ensuring DNA repair and cell survival in response to high-energy high LET radiation.

  4. “Accelerating Science” exhibition zooms to Turkey

    CERN Multimedia

    Joannah Caborn Wengler

    2012-01-01

    'Accelerating Science', CERN’s travelling science outreach exhibition, has just arrived at the Middle East Technical University (METU) in Ankara, Turkey for a four-month stay there. This is the first time it has moved outside the circle of the Member States. The Turkish venue will inaugurate some new exhibits that have recently been developed by CERN’s software developers.   “It’s been a very busy day,” says Bilge Demirkoz, an associate professor of physics at METU and a member of AMS-02, who had been overseeing the unloading of the lorries when we spoke to her. “As the University doesn’t have a specific exhibition space, the CERN exhibits are going to be housed in the covered tennis courts just behind the cultural and congress centre. It’s a beautiful venue, and there are plenty of parking spaces.” The University has sent invitations to the exhibition to high schools and to about 100 ...

  5. Isolation and identification of the human homolog of a new p53-binding protein, Mdmx

    NARCIS (Netherlands)

    Shvarts, A.; Bazuine, M.; Dekker, P.; Ramos, Y. F.; Steegenga, W. T.; Merckx, G.; van Ham, R. C.; van der Houven van Oordt, W.; van der Eb, A. J.; Jochemsen, A. G.

    1997-01-01

    We recently reported the identification of a mouse cDNA encoding a new p53-associating protein that we called Mdmx because of its structural similarity to Mdm2, a well-known p53-binding protein. Here we report the isolation of a cDNA encoding the human homolog of Mdmx. The ORF of the cDNA encodes a

  6. Vitamin E homologs and ¿-oryzanol levels in rice (Oryza sativa L.) during seed development

    Science.gov (United States)

    Vitamin E homologs (tocopherols and tocotrienols) and gamma-oryzanol have gained significant attention due to their proposed health benefits and ability to increase vegetable oil stability. Changes in the levels of these phytochemicals were examined during seed development. Rapid accumulation of toc...

  7. Identification of the porcine homologous of human disease causing trinucleotide repeat sequences

    DEFF Research Database (Denmark)

    Madsen, Lone Bruhn; Thomsen, Bo; Sølvsten, Christina Ane Elisabeth

    2007-01-01

    in this paper the identification of porcine noncoding and polyglutamine-encoding TNR regions and the comparison to the homologous TNRs from human, chimpanzee, dog, opossum, rat, and mouse. Several of the porcine TNR regions are highly polymorphic both within and between different breeds. The TNR regions...

  8. Evolution and homology of the astragalus in early amniotes: new fossils, new perspectives.

    Science.gov (United States)

    O'Keefe, F Robin; Sidor, Christian A; Larsson, Hans C E; Maga, Abdoudaye; Ide, Oumarou

    2006-04-01

    The reorganization of the ankle in basal amniotes has long been considered a key innovation allowing the evolution of more terrestrial and cursorial behavior. Understanding how this key innovation arose is a complex problem that largely concerns the homologizing of the amniote astragalus with the various ossifications in the anamniote tarsus. Over the last century, several hypotheses have been advanced homologizing the amniote astragalus with the many ossifications in the ankle of amphibian-grade tetrapods. There is an emerging consensus that the amniote astragalus is a complex structure emerging via the co-ossification of several originally separate elements, but the identities of these elements remain unclear. Here we present new fossil evidence bearing on this contentious question. A poorly ossified, juvenile astragalus of the large captorhinid Moradisaurus grandis shows clear evidence of four ossification centers, rather than of three centers or one center as posited in previous models of astragalus homology. Comparative material of the captorhinid Captorhinikos chozaensis is also interpretable as demonstrating four ossification centers. A new, four-center model for the homology of the amniote astragalus is advanced, and is discussed in the context of the phylogeny of the Captorhinidae in an attempt to identify the developmental transitions responsible for the observed pattern of ossification within this clade. Lastly, the broader implications for amniote phylogeny are discussed, concluding that the neomorphic pattern of astragalus ossification seen in all extant reptiles (including turtles) arose within the clade Diapsida.

  9. Resistance of hypoxic cells to ionizing radiation is influenced by homologous recombination status

    International Nuclear Information System (INIS)

    Sprong, Debbie; Janssen, Hilde L.; Vens, Conchita; Begg, Adrian C.

    2006-01-01

    Purpose: To determine the role of DNA repair in hypoxic radioresistance. Methods and Materials: Chinese hamster cell lines with mutations in homologous recombination (XRCC2, XRCC3, BRAC2, RAD51C) or nonhomologous end-joining (DNA-PKcs) genes were irradiated under normoxic (20% oxygen) and hypoxic (<0.1% oxygen) conditions, and the oxygen enhancement ratio (OER) was calculated. In addition, Fanconi anemia fibroblasts (complementation groups C and G) were compared with fibroblasts from nonsyndrome patients. RAD51 foci were studied using immunofluorescence. Results: All hamster cell lines deficient in homologous recombination showed a decrease in OER (1.5-2.0 vs. 2.6-3.0 for wild-types). In contrast, the OER for the DNA-PKcs-deficient line was comparable to wild-type controls. The two Fanconi anemia cell strains also showed a significant reduction in OER. The OER for RAD51 foci formation at late times after irradiation was considerably lower than that for survival in wild-type cells. Conclusion: Homologous recombination plays an important role in determining hypoxic cell radiosensitivity. Lower OERs have also been reported in cells deficient in XPF and ERCC1, which, similar to homologous recombination genes, are known to play a role in cross-link repair. Because Fanconi anemia cells are also sensitive to cross-linking agents, this strengthens the notion that the capacity to repair cross-links determines hypoxic radiosensitivity

  10. Refinement of homology-based protein structures by molecular dynamics simulation techniques

    NARCIS (Netherlands)

    Fan, H; Mark, AE

    The use of classical molecular dynamics simulations, performed in explicit water, for the refinement of structural models of proteins generated ab initio or based on homology has been investigated. The study involved a test set of 15 proteins that were previously used by Baker and coworkers to

  11. Direct Single-Molecule Observation of Mode and Geometry of RecA-Mediated Homology Search.

    Science.gov (United States)

    Lee, Andrew J; Endo, Masayuki; Hobbs, Jamie K; Wälti, Christoph

    2018-01-23

    Genomic integrity, when compromised by accrued DNA lesions, is maintained through efficient repair via homologous recombination. For this process the ubiquitous recombinase A (RecA), and its homologues such as the human Rad51, are of central importance, able to align and exchange homologous sequences within single-stranded and double-stranded DNA in order to swap out defective regions. Here, we directly observe the widely debated mechanism of RecA homology searching at a single-molecule level using high-speed atomic force microscopy (HS-AFM) in combination with tailored DNA origami frames to present the reaction targets in a way suitable for AFM-imaging. We show that RecA nucleoprotein filaments move along DNA substrates via short-distance facilitated diffusions, or slides, interspersed with longer-distance random moves, or hops. Importantly, from the specific interaction geometry, we find that the double-stranded substrate DNA resides in the secondary DNA binding-site within the RecA nucleoprotein filament helical groove during the homology search. This work demonstrates that tailored DNA origami, in conjunction with HS-AFM, can be employed to reveal directly conformational and geometrical information on dynamic protein-DNA interactions which was previously inaccessible at an individual single-molecule level.

  12. Interference of Homologous Sequences on the SNP Study of CYP2A13 Gene

    Directory of Open Access Journals (Sweden)

    Qinghua ZHOU

    2010-02-01

    Full Text Available Background and objective It has been proven that cytochrome P450 enzyme 2A13 (CYP2A13 played an important role in the association between single nucleotide polymorphisms (SNP and human diseases. Cytochrome P450 enzymes are a group of isoenzymes, whose sequence homology may interfere with the study for SNP. The aim of this study is to explore the interference on the SNP study of CYP2A13 caused by homologous sequences. Methods Taqman probe was applied to detect distribution of rs8192789 sites in 573 subjects, and BLAST method was used to analyze the amplified sequences. Partial sequences of CYP2A13 were emplified by PCR from 60 cases. The emplified sequences were TA cloned and sequenced. Results For rs8192789 loci in 573 cases, only 3 cases were TT, while the rest were CT heterozygotes, which was caused by homologous sequences. There are a large number of overlapping peaks in identical sequences of 60 cases, and the SNP of 101 amino acid site reported in the SNP database is not found. The cloned sequences are 247 bp, 235 bp fragments. Conclusion The homologous sequences may interfere the study for SNP of CYP2A13, and some SNP may not exist.

  13. Metabolism of homologous and heterologous serum proteins in garter snakes (Thamnophis ordinoides)

    International Nuclear Information System (INIS)

    Leong, D.; Coe, J.E.

    1978-01-01

    The half-life (Tsub(1/2) of serum immunoglobulin (Ig) and albumin from snakes and mammals were determined in both garter snakes (Thamnophis ordinoides) and mice (Mus musculus). Metabolism of serum proteins in snakes was similar to mammalian protein metabolism in that homologous serum albumin had shorter Tsub(1/2) (16 days) than IgG (38 days). Also, reptilian and mammalian serum proteins had a relatively longer Tsub(1/2) when injected into closely related species. Thus mammalian serum Ig (rabbit gamma globulin (RGG)) had a shorter Tsub(1/2) (6.3 days) in snake than did homologous snake IgG (38 days), whereas in mice, RGG had a longer Tsub(1/2) (3.8 days) than snake Ig (0.9 days). Differences between metabolism of homologous and heterologous albumins were apparent only in snakes in which the Tsub(1/2) of homologous albumin was approximately 8-fold greater than mammalian albumin. These results indicate that metabolism of both Ig and albumin in snakes is regulated by specific receptors whereas albumin receptors have been difficult to demonstrate in mammals. The results of this study suggest that one of the factors determining the metabolism of a protein is its foreignness to the host perhaps because of receptor cross reactions. (author)

  14. In vivo genome editing via CRISPR/Cas9 mediated homology-independent targeted integration

    KAUST Repository

    Suzuki, Keiichiro; Tsunekawa, Yuji; Herná ndez-Bení tez, Reyna; Wu, Jun; Zhu, Jie; Kim, Euiseok J.; Hatanaka, Fumiyuki; Yamamoto, Mako; Araoka, Toshikazu; Li, Zhe; Kurita, Masakazu; Hishida, Tomoaki; Li, Mo; Aizawa, Emi; Guo, Shicheng; Chen, Song; Goebl, April; Soligalla, Rupa Devi; Qu, Jing; Jiang, Tingshuai; Fu, Xin; Jafari, Maryam; Esteban, Concepcion Rodriguez; Berggren, W. Travis; Lajara, Jeronimo; Nuñ ez-Delicado, Estrella; Guillen, Pedro; Campistol, Josep M.; Matsuzaki, Fumio; Liu, Guang-Hui; Magistretti, Pierre J.; Zhang, Kun; Callaway, Edward M.; Zhang, Kang; Belmonte, Juan Carlos Izpisua

    2016-01-01

    regularly interspaced short palindromic repeat/Cas9 (CRISPR/Cas9)3, 4 technology, here we devise a homology-independent targeted integration (HITI) strategy, which allows for robust DNA knock-in in both dividing and non-dividing cells in vitro and, more

  15. Homology modeling of the serotonin transporter: Insights into the primary escitalopram-binding Site

    DEFF Research Database (Denmark)

    Jørgensen, Anne Marie; Tagmose, L.; Jørgensen, A.M.M.

    2007-01-01

    -ray structure of the closely related amino acid transporter, Aquifex aeolicus leucine transporter (LeuT), provides an opportunity to develop a three-dimensional model of the structure of SERT. We present herein a homology model of SERT using LeuT as the template and containing escitalopram as a bound ligand...

  16. Mammalian Sir2 homolog SIRT3 regulates global mitochondrial lysine acetylation

    DEFF Research Database (Denmark)

    Lombard, David B; Alt, Frederick W; Cheng, Hwei-Ling

    2007-01-01

    Homologs of the Saccharomyces cerevisiae Sir2 protein, sirtuins, promote longevity in many organisms. Studies of the sirtuin SIRT3 have so far been limited to cell culture systems. Here, we investigate the localization and function of SIRT3 in vivo. We show that endogenous mouse SIRT3 is a solubl...

  17. Uncoupling protein homologs may provide a link between mitochondria, metabolism and lifespan.

    Science.gov (United States)

    Wolkow, Catherine A; Iser, Wendy B

    2006-05-01

    Uncoupling proteins (UCPs), which dissipate the mitochondrial proton gradient, have the ability to decouple mitochodrial respiration from ATP production. Since mitochondrial electron transport is a major source of free radical production, it is possible that UCP activity might impact free radical production. Free radicals can react with and damage cellular proteins, DNA and lipids. Accumulated damage from oxidative stress is believed to be a major contributor to cellular decline during aging. If UCP function were to impact mitochondrial free radical production, then one would expect to find a link between UCP activity and aging. This theory has recently been tested in a handful of organisms whose genomes contain UCP1 homologs. Interestingly, these experiments indicate that UCP homologs can affect lifespan, although they do not support a simple relationship between UCP activity and aging. Instead, UCP-like proteins appear to have a variety of effects on lifespan, and on pathways implicated in lifespan regulation. One possible explanation for this complex picture is that UCP homologs may have tissue-specific effects that complicate their effects on aging. Furthermore, the functional analysis of UCP1 homologs is incomplete. Thus, these proteins may perform functions in addition to, or instead of, mitochondrial uncoupling. Although these studies have not revealed a clear picture of UCP effects on aging, they have contributed to the growing knowledge base for these interesting proteins. Future biochemical and genetic investigation of UCP-like proteins will do much to clarify their functions and to identify the regulatory networks in which they are involved.

  18. Searching remote homology with spectral clustering with symmetry in neighborhood cluster kernels.

    Directory of Open Access Journals (Sweden)

    Ujjwal Maulik

    Full Text Available Remote homology detection among proteins utilizing only the unlabelled sequences is a central problem in comparative genomics. The existing cluster kernel methods based on neighborhoods and profiles and the Markov clustering algorithms are currently the most popular methods for protein family recognition. The deviation from random walks with inflation or dependency on hard threshold in similarity measure in those methods requires an enhancement for homology detection among multi-domain proteins. We propose to combine spectral clustering with neighborhood kernels in Markov similarity for enhancing sensitivity in detecting homology independent of "recent" paralogs. The spectral clustering approach with new combined local alignment kernels more effectively exploits the unsupervised protein sequences globally reducing inter-cluster walks. When combined with the corrections based on modified symmetry based proximity norm deemphasizing outliers, the technique proposed in this article outperforms other state-of-the-art cluster kernels among all twelve implemented kernels. The comparison with the state-of-the-art string and mismatch kernels also show the superior performance scores provided by the proposed kernels. Similar performance improvement also is found over an existing large dataset. Therefore the proposed spectral clustering framework over combined local alignment kernels with modified symmetry based correction achieves superior performance for unsupervised remote homolog detection even in multi-domain and promiscuous domain proteins from Genolevures database families with better biological relevance. Source code available upon request.sarkar@labri.fr.

  19. Cloning and homologic analysis of Tpn I gene in silkworm Bombyx ...

    African Journals Online (AJOL)

    GREGO

    2007-03-19

    Mar 19, 2007 ... 1Institute of Life Sciences, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, P. R. China. ... Key words: Tpn I, Bombyx mori, troponin, homology. ... cycles (94ºC for 30 s, 58ºC for 30 s, 72ºC for 3 min) in a Gene Amp.

  20. A recurrent translocation is mediated by homologous recombination between HERV-H elements

    Directory of Open Access Journals (Sweden)

    Hermetz Karen E

    2012-01-01

    Full Text Available Abstract Background Chromosome rearrangements are caused by many mutational mechanisms; of these, recurrent rearrangements can be particularly informative for teasing apart DNA sequence-specific factors. Some recurrent translocations are mediated by homologous recombination between large blocks of segmental duplications on different chromosomes. Here we describe a recurrent unbalanced translocation casued by recombination between shorter homologous regions on chromosomes 4 and 18 in two unrelated children with intellectual disability. Results Array CGH resolved the breakpoints of the 6.97-Megabase (Mb loss of 18q and the 7.30-Mb gain of 4q. Sequencing across the translocation breakpoints revealed that both translocations occurred between 92%-identical human endogenous retrovirus (HERV elements in the same orientation on chromosomes 4 and 18. In addition, we find sequence variation in the chromosome 4 HERV that makes one allele more like the chromosome 18 HERV. Conclusions Homologous recombination between HERVs on the same chromosome is known to cause chromosome deletions, but this is the first report of interchromosomal HERV-HERV recombination leading to a translocation. It is possible that normal sequence variation in substrates of non-allelic homologous recombination (NAHR affects the alignment of recombining segments and influences the propensity to chromosome rearrangement.