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Sample records for nonribosomal peptide-polyketide origin

  1. A hybrid non-ribosomal peptide/polyketide synthetase containing fatty-acyl ligase (FAAL synthesizes the β-amino fatty acid lipopeptides puwainaphycins in the Cyanobacterium Cylindrospermum alatosporum.

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    Jan Mareš

    Full Text Available A putative operon encoding the biosynthetic pathway for the cytotoxic cyanobacterial lipopeptides puwainphycins was identified in Cylindrospermum alatosporum. Bioinformatics analysis enabled sequential prediction of puwainaphycin biosynthesis; this process is initiated by the activation of a fatty acid residue via fatty acyl-AMP ligase and continued by a multidomain non-ribosomal peptide synthetase/polyketide synthetase. High-resolution mass spectrometry and nuclear magnetic resonance spectroscopy measurements proved the production of puwainaphycin F/G congeners differing in FA chain length formed by either 3-amino-2-hydroxy-4-methyl dodecanoic acid (4-methyl-Ahdoa or 3-amino-2-hydroxy-4-methyl tetradecanoic acid (4-methyl-Ahtea. Because only one puwainaphycin operon was recovered in the genome, we suggest that the fatty acyl-AMP ligase and one of the amino acid adenylation domains (Asn/Gln show extended substrate specificity. Our results provide the first insight into the biosynthesis of frequently occurring β-amino fatty acid lipopeptides in cyanobacteria, which may facilitate analytical assessment and development of monitoring tools for cytotoxic cyanobacterial lipopeptides.

  2. Nonribosomal biosynthesis of backbone-modified peptides

    Science.gov (United States)

    Niquille, David L.; Hansen, Douglas A.; Mori, Takahiro; Fercher, David; Kries, Hajo; Hilvert, Donald

    2018-03-01

    Biosynthetic modification of nonribosomal peptide backbones represents a potentially powerful strategy to modulate the structure and properties of an important class of therapeutics. Using a high-throughput assay for catalytic activity, we show here that an L-Phe-specific module of an archetypal nonribosomal peptide synthetase can be reprogrammed to accept and process the backbone-modified amino acid (S)-β-Phe with near-native specificity and efficiency. A co-crystal structure with a non-hydrolysable aminoacyl-AMP analogue reveals the origins of the 40,000-fold α/β-specificity switch, illuminating subtle but precise remodelling of the active site. When the engineered catalyst was paired with downstream module(s), (S)-β-Phe-containing peptides were produced at preparative scale in vitro (~1 mmol) and high titres in vivo (~100 mg l-1), highlighting the potential of biosynthetic pathway engineering for the construction of novel nonribosomal β-frameworks.

  3. Isolation and Assessment of the in Vitro Anti-Tumor Activity of Smenothiazole A and B, Chlorinated Thiazole-Containing Peptide/Polyketides from the Caribbean Sponge, Smenospongia aurea

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    Germana Esposito

    2015-01-01

    Full Text Available The study of the secondary metabolites contained in the organic extract of Caribbean sponge Smenospongia aurea led to the isolation of smenothiazole A (3 and B (4, hybrid peptide/polyketide compounds. Assays performed using four solid tumor cell lines showed that smenothiazoles exert a potent cytotoxic activity at nanomolar levels, with selectivity over ovarian cancer cells and a pro-apoptotic mechanism.

  4. A hybrid non-ribosomal peptide/polyketide synthetase containing fatty-acyl ligase (FAAL) synthesizes the β-amino fatty acid lipopeptides puwainaphycins in the cyanobacterium Cylindrospermum alatosporum

    Czech Academy of Sciences Publication Activity Database

    Mareš, Jan; Hájek, Jan; Urajová, P.; Kopecký, J.; Hrouzek, P.

    2014-01-01

    Roč. 9, č. 11 (2014), e111904 E-ISSN 1932-6203 R&D Projects: GA ČR(CZ) GA14-18067S Institutional support: RVO:60077344 Keywords : cyanobacteria * lipopeptides * biosynthesis Subject RIV: CE - Biochemistry Impact factor: 3.234, year: 2014

  5. A Hybrid Non-Ribosomal Peptide/Polyketide Synthetase Containing Fatty-Acyl Ligase (FAAL) Synthesizes the beta-Amino Fatty Acid Lipopeptides Puwainaphycins in the Cyanobacterium Cylindrospermum alatosporum

    Czech Academy of Sciences Publication Activity Database

    Mareš, J.; Hájek, J.; Urajová, Petra; Kopecký, Jiří; Hrouzek, Pavel

    2014-01-01

    Roč. 9, č. 11 (2014) E-ISSN 1932-6203 R&D Projects: GA MŠk ED2.1.00/03.0110; GA ČR GA14-18067S Institutional support: RVO:61388971 Keywords : blue green alga * FAAL * Cylindrospermum alatosporum Subject RIV: CE - Biochemistry Impact factor: 3.234, year: 2014

  6. Genome Sequence of Dickeya solani, a New soft Rot Pathogen of Potato, Suggests its Emergence May Be Related to a Novel Combination of Non-Ribosomal Peptide/Polyketide Synthetase Clusters

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    Linda Garlant

    2013-12-01

    Full Text Available Soft rot Enterobacteria in the genera Pectobacterium and Dickeya cause rotting of many crop plants. A new Dickeya isolate has been suggested to form a separate species, given the name Dickeya solani. This bacterium is spreading fast and replacing the closely related, but less virulent, potato pathogens. The genome of D. solani isolate D s0432-1 shows highest similarity at the nucleotide level and in synteny to D. dadantii strain 3937, but it also contains three large polyketide/fatty acid/non-ribosomal peptide synthetase clusters that are not present in D. dadantii 3937. These gene clusters may be involved in the production of toxic secondary metabolites, such as oocydin and zeamine. Furthermore, the D. solani genome harbors several specific genes that are not present in other Dickeya and Pectobacterium species and that may confer advantages for adaptation to new environments. In conclusion, the fast spreading of D. solani may be related to the acquisition of new properties that affect its interaction with plants and other microbes in the potato ecosystem.

  7. An Sfp-type PPTase and associated polyketide and nonribosomal peptide synthases in Agrobacterium vitis are essential for induction of tobacco hypersensitive response and grape necrosis.

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    Zheng, Desen; Burr, Thomas J

    2013-07-01

    An Sfp-type phosphopantetheinyl transferase (PPTase) encoding gene F-avi5813 in Agrobacterium vitis F2/5 was found to be required for the induction of a tobacco hypersensitive response (HR) and grape necrosis. Sfp-type PPTases are post-translation modification enzymes that activate acyl-carry protein (ACP) domains in polyketide synthases (PKS) and peptidyl-carrier protein (PCP) domains of nonribosomal peptide synthases (NRPS). Mutagenesis of PKS and NRPS genes in A. vitis led to the identification of a PKS gene (F-avi4330) and NRPS gene (F-avi3342) that are both required for HR and necrosis. The gene immediately downstream of F-avi4330 (F-avi4329) encoding a predicted aminotransferase was also found to be required for HR and necrosis. Regulation of F-avi4330 and F-avi3342 by quorum-sensing genes avhR, aviR, and avsR and by a lysR-type regulator, lhnR, was investigated. It was determined that F-avi4330 expression is positively regulated by avhR, aviR, and lhnR and negatively regulated by avsR. F-avi3342 was found to be positively regulated by avhR, aviR, and avsR and negatively regulated by lhnR. Our results suggest that a putative hybrid peptide-polyketide metabolite synthesized by F-avi4330 and F-avi3342 is associated with induction of tobacco HR and grape necrosis. This is the first report that demonstrates that NRPS and PKS play essential roles in conferring the unique ability of A. vitis to elicit a non-host-specific HR and host-specific necrosis.

  8. De novo design and engineering of non-ribosomal peptide synthetases

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    Bozhüyük, Kenan A. J.; Fleischhacker, Florian; Linck, Annabell; Wesche, Frank; Tietze, Andreas; Niesert, Claus-Peter; Bode, Helge B.

    2018-03-01

    Peptides derived from non-ribosomal peptide synthetases (NRPSs) represent an important class of pharmaceutically relevant drugs. Methods to generate novel non-ribosomal peptides or to modify peptide natural products in an easy and predictable way are therefore of great interest. However, although the overall modular structure of NRPSs suggests the possibility of adjusting domain specificity and selectivity, only a few examples have been reported and these usually show a severe drop in production titre. Here we report a new strategy for the modification of NRPSs that uses defined exchange units (XUs) and not modules as functional units. XUs are fused at specific positions that connect the condensation and adenylation domains and respect the original specificity of the downstream module to enable the production of the desired peptides. We also present the use of internal condensation domains as an alternative to other peptide-chain-releasing domains for the production of cyclic peptides.

  9. Structural pattern matching of nonribosomal peptides

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    Leclère Valérie

    2009-03-01

    Full Text Available Abstract Background Nonribosomal peptides (NRPs, bioactive secondary metabolites produced by many microorganisms, show a broad range of important biological activities (e.g. antibiotics, immunosuppressants, antitumor agents. NRPs are mainly composed of amino acids but their primary structure is not always linear and can contain cycles or branchings. Furthermore, there are several hundred different monomers that can be incorporated into NRPs. The NORINE database, the first resource entirely dedicated to NRPs, currently stores more than 700 NRPs annotated with their monomeric peptide structure encoded by undirected labeled graphs. This opens a way to a systematic analysis of structural patterns occurring in NRPs. Such studies can investigate the functional role of some monomeric chains, or analyse NRPs that have been computationally predicted from the synthetase protein sequence. A basic operation in such analyses is the search for a given structural pattern in the database. Results We developed an efficient method that allows for a quick search for a structural pattern in the NORINE database. The method identifies all peptides containing a pattern substructure of a given size. This amounts to solving a variant of the maximum common subgraph problem on pattern and peptide graphs, which is done by computing cliques in an appropriate compatibility graph. Conclusion The method has been incorporated into the NORINE database, available at http://bioinfo.lifl.fr/norine. Less than one second is needed to search for a pattern in the entire database.

  10. SANDPUMA: ensemble predictions of nonribosomal peptide chemistry reveal biosynthetic diversity across Actinobacteria

    NARCIS (Netherlands)

    Chevrette, Marc G.; Aicheler, Fabian; Kohlbacher, Oliver; Currie, Cameron R.; Medema, M.H.

    2017-01-01

    Nonribosomally synthesized peptides (NRPs) are natural products with widespread applications in medicine and biotechnology. Many algorithms have been developed to predict the substrate specificities of nonribosomal peptide synthetase adenylation (A) domains from DNA sequences, which enables

  11. Bioinformatics Tools for the Discovery of New Nonribosomal Peptides

    DEFF Research Database (Denmark)

    Leclère, Valérie; Weber, Tilmann; Jacques, Philippe

    2016-01-01

    -dimensional structure of the peptides can be compared with the structural patterns of all known NRPs. The presented workflow leads to an efficient and rapid screening of genomic data generated by high throughput technologies. The exploration of such sequenced genomes may lead to the discovery of new drugs (i......This chapter helps in the use of bioinformatics tools relevant to the discovery of new nonribosomal peptides (NRPs) produced by microorganisms. The strategy described can be applied to draft or fully assembled genome sequences. It relies on the identification of the synthetase genes...... and the deciphering of the domain architecture of the nonribosomal peptide synthetases (NRPSs). In the next step, candidate peptides synthesized by these NRPSs are predicted in silico, considering the specificity of incorporated monomers together with their isomery. To assess their novelty, the two...

  12. Structural basis of nonribosomal peptide macrocyclization in fungi.

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    Zhang, Jinru; Liu, Nicholas; Cacho, Ralph A; Gong, Zhou; Liu, Zhu; Qin, Wenming; Tang, Chun; Tang, Yi; Zhou, Jiahai

    2016-12-01

    Nonribosomal peptide synthetases (NRPSs) in fungi biosynthesize important pharmaceutical compounds, including penicillin, cyclosporine and echinocandin. To understand the fungal strategy of forging the macrocyclic peptide linkage, we determined the crystal structures of the terminal condensation-like (C T ) domain and the holo thiolation (T)-C T complex of Penicillium aethiopicum TqaA. The first, to our knowledge, structural depiction of the terminal module in a fungal NRPS provides a molecular blueprint for generating new macrocyclic peptide natural products.

  13. Nonribosomal Peptides from Marine Microbes and Their Antimicrobial and Anticancer Potential

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    Shivankar Agrawal

    2017-11-01

    Full Text Available Marine environments are largely unexplored and can be a source of new molecules for the treatment of many diseases such as malaria, cancer, tuberculosis, HIV etc. The Marine environment is one of the untapped bioresource of getting pharmacologically active nonribosomal peptides (NRPs. Bioprospecting of marine microbes have achieved many remarkable milestones in pharmaceutics. Till date, more than 50% of drugs which are in clinical use belong to the nonribosomal peptide or mixed polyketide-nonribosomal peptide families of natural products isolated from marine bacteria, cyanobacteria and fungi. In recent years large numbers of nonribosomal have been discovered from marine microbes using multi-disciplinary approaches. The present review covers the NRPs discovered from marine microbes and their pharmacological potential along with role of genomics, proteomics and bioinformatics in discovery and development of nonribosomal peptides drugs.

  14. Nonribosomal Peptide Synthetase Genes pesL and pes1 Are Essential for Fumigaclavine C Production in Aspergillus fumigatus

    DEFF Research Database (Denmark)

    O'Hanlon, Karen A.; Gallagher, Lorna; Schrettl, Markus

    2012-01-01

    The identity of metabolites encoded by the majority of nonribosomal peptide synthetases in the opportunistic pathogen, Aspergillus fumigatus, remains outstanding. We found that the nonribosomal peptide (NRP) synthetases PesL and Pes1 were essential for fumigaclavine C biosynthesis, the end produc...

  15. Implementation of communication-mediating domains for non-ribosomal peptide production in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Siewers, Verena; San-Bento, Rita; Nielsen, Jens

    2010-01-01

    Saccharomyces cerevisiae has in several cases been proven to be a suitable host for the production of natural products and was recently exploited for the production of non-ribosomal peptides. Synthesis of non-ribosomal peptides (NRPs) is mediated by NRP synthetases (NRPSs), modular enzymes, which...... are often organized in enzyme complexes. In these complexes, partner NRPSs interact via communication-mediating domains (COM domains). In order to test whether functional interaction between separate NRPS modules is possible in yeast we constructed a yeast strain expressing two modules with compatible COM...

  16. Computational discovery of specificity-conferring sites in non-ribosomal peptide synthetases

    DEFF Research Database (Denmark)

    Knudsen, Michael; Søndergaard, Dan Ariel; Tofting-Olesen, Claus

    2016-01-01

    Motivation: By using a class of large modular enzymes known as Non-Ribosomal Peptide Synthetases (NRPS), bacteria and fungi are capable of synthesizing a large variety of secondary metabolites, many of which are bioactive and have potential, pharmaceutical applications as e.g.~antibiotics. There ...

  17. CycloBranch: De Novo Sequencing of Nonribosomal Peptides from Accurate Product Ion Mass Spectra

    Czech Academy of Sciences Publication Activity Database

    Novák, Jiří; Lemr, Karel; Schug, K. A.; Havlíček, Vladimír

    2015-01-01

    Roč. 26, č. 10 (2015), s. 1780-1786 ISSN 1044-0305 R&D Projects: GA ČR(CZ) GAP206/12/1150 Grant - others:OPPC(XE) CZ.2.16/3.1.00/24023 Institutional support: RVO:61388971 Keywords : De novo sequencing * Nonribosomal peptides * Linear Subject RIV: CE - Biochemistry Impact factor: 3.031, year: 2015

  18. A proteomic survey of nonribosomal peptide and polyketide biosynthesis in actinobacteria

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    Actinobacteria such as streptomycetes are renowned for their ability to produce bioactive natural products including nonribosomal peptides (NRPs) and polyketides (PKs). The advent of genome sequencing has revealed an even larger genetic repertoire for secondary metabolism with most of the small mole...

  19. Structural basis for phosphopantetheinyl carrier domain interactions in the terminal module of nonribosomal peptide synthetases

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    Liu, Ye; Zheng, Tengfei; Bruner, Steven D.

    2011-01-01

    Summary Phosphopantetheine-modified carrier domains play a central role in the template-directed, biosynthesis of several classes of primary and secondary metabolites. Fatty acids, polyketides and nonribosomal peptides are constructed on multidomain enzyme assemblies using phosphopantetheinyl thioester-linked carrier domains to traffic and activate building blocks. The carrier domain is a dynamic component of the process, shuttling pathway intermediates to sequential enzyme active sites. Here we report an approach to structurally fix carrier domain/enzyme constructs suitable for X-ray crystallographic analysis. The structure of a two-domain construct of E. coli EntF was determined with a conjugated phosphopantetheinyl-based inhibitor. The didomain structure is locked in an active orientation relevant to the chemistry of nonribosomal peptide biosynthesis. This structure provides details into the interaction of phosphopantetheine arm with the carrier domain and the active site of the thioesterase domain. PMID:22118682

  20. Origin,

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    Artur de Vargas Giorgi

    2011-02-01

    Full Text Available This essay tightens the “origin” concept, its manifestation through puzzles and their relationship to techniques of reproduction. Contrary to the hegemonic critique of aesthetic and cultural objects – critique that, settled on the appearance and notions of identity, tradition, canon, etc., undervalues the reproductions of "originals" –, the aim is to deliver these objects from formal hierarchization dispositives, that is, release them of what is ideal and positively imposed, so that the reproducibility is potentiated as producer of singularities, of apparitions. The effort is to keep the undecided character of puzzles (bodies, texts, images in which the origin is manifest, so that the logic of the spectacle is reverted into sense opening, instance in which the aesthetic becomes a “performance” before contemporary complexity. With the reproducibility, an origin survives in passage: continually restored, but incomplete, present in trace, in absence.

  1. Prediction of monomer isomery in Florine: a workflow dedicated to nonribosomal peptide discovery.

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    Thibault Caradec

    Full Text Available Nonribosomal peptides represent a large variety of natural active compounds produced by microorganisms. Due to their specific biosynthesis pathway through large assembly lines called NonRibosomal Peptide Synthetases (NRPSs, they often display complex structures with cycles and branches. Moreover they often contain non proteogenic or modified monomers, such as the D-monomers produced by epimerization. We investigate here some sequence specificities of the condensation (C and epimerization (E domains of NRPS that can be used to predict the possible isomeric state (D or L of each monomer in a putative peptide. We show that C- and E- domains can be divided into 2 sub-regions called Up-Seq and Down-Seq. The Up-Seq region corresponds to an InterPro domain (IPR001242 and is shared by C- and E-domains. The Down-Seq region is specific to the enzymatic activity of the domain. Amino-acid signatures (represented as sequence logos previously described for complete C-and E-domains have been restricted to the Down-Seq region and amplified thanks to additional sequences. Moreover a new Down-Seq signature has been found for Ct-domains found in fungi and responsible for terminal cyclization of the peptides. The identification of these signatures has been included in a workflow named Florine, aimed to predict nonribosomal peptides from NRPS sequence analyses. In some cases, the prediction of isomery is guided by genus-specific rules. Florine was used on a Pseudomonas genome to allow the determination of the type of pyoverdin produced, the update of syringafactin structure and the identification of novel putative products.

  2. Quick guide to polyketide synthase and nonribosomal synthetase genes in Fusarium

    DEFF Research Database (Denmark)

    Hansen, Jørgen T.; Sørensen, Jens L.; Giese, Henriette

    2012-01-01

    Fusarium species produce a plethora of bioactive polyketides and nonribosomal peptides that give rise to health problems in animals and may have drug development potential. Using the genome sequences for Fusarium graminearum, F. oxysporum, F. solani and F. verticillioides we developed a framework...... and NRPS genes in sequenced Fusarium species and their known products. With the rapid increase in the number of sequenced fungal genomes a systematic classification will greatly aid the scientific community in obtaining an overview of the number of different NRPS and PKS genes and their potential...

  3. A nonribosomal peptide synthetase (Pes1) confers protection against oxidative stress in Aspergillus fumigatus.

    Science.gov (United States)

    Reeves, Emer P; Reiber, Kathrin; Neville, Claire; Scheibner, Olaf; Kavanagh, Kevin; Doyle, Sean

    2006-07-01

    Aspergillus fumigatus is an important human fungal pathogen. The Aspergillus fumigatus genome contains 14 nonribosomal peptide synthetase genes, potentially responsible for generating metabolites that contribute to organismal virulence. Differential expression of the nonribosomal peptide synthetase gene, pes1, in four strains of Aspergillus fumigatus was observed. The pattern of pes1 expression differed from that of a putative siderophore synthetase gene, sidD, and so is unlikely to be involved in iron acquisition. The Pes1 protein (expected molecular mass 698 kDa) was partially purified and identified by immunoreactivity, peptide mass fingerprinting (36% sequence coverage) and MALDI LIFT-TOF/TOF MS (four internal peptides sequenced). A pes1 disruption mutant (delta pes1) of Aspergillus fumigatus strain 293.1 was generated and confirmed by Southern and western analysis, in addition to RT-PCR. The delta pes1 mutant also showed significantly reduced virulence in the Galleria mellonella model system (P < 0.001) and increased sensitivity to oxidative stress (P = 0.002) in culture and during neutrophil-mediated phagocytosis. In addition, the mutant exhibited altered conidial surface morphology and hydrophilicity, compared to Aspergillus fumigatus 293.1. It is concluded that pes1 contributes to improved fungal tolerance against oxidative stress, mediated by the conidial phenotype, during the infection process.

  4. A 4'-phosphopantetheinyl transferase mediates non-ribosomal peptide synthetase activation in Aspergillus fumigatus.

    Science.gov (United States)

    Neville, Claire; Murphy, Alan; Kavanagh, Kevin; Doyle, Sean

    2005-04-01

    Aspergillus fumigatus is a significant human pathogen. Non-ribosomal peptide (NRP) synthesis is thought to be responsible for a significant proportion of toxin and siderophore production in the organism. Furthermore, it has been shown that 4'-phosphopantetheinylation is required for the activation of key enzymes involved in non-ribosomal peptide synthesis in other species. Here we report the cloning, recombinant expression and functional characterisation of a 4'-phosphopantetheinyl transferase from A. fumigatus and the identification of an atypical NRP synthetase (Afpes1), spanning 14.3 kb. Phylogenetic analysis has shown that the NRP synthetase exhibits greatest identity to NRP synthetases from Metarhizium anisolpiae (PesA) and Alternaria brassicae (AbrePsy1). Northern hybridisation and RT-PCR analysis have confirmed that both genes are expressed in A. fumigatus. A 120 kDa fragment of the A. fumigatus NRP synthetase, containing a putative thiolation domain, was cloned and expressed in the baculovirus expression system. Detection of a 4'-phosphopantetheinylated peptide (SFSAMK) from this protein, by MALDI-TOF mass spectrometric analysis after coincubation of the 4'-phosphopantetheinyl transferase with the recombinant NRP synthetase fragment and acetyl CoA, confirms that it is competent to play a role in NRP synthetase activation in A. fumigatus. The 4'-phosphopantetheinyl transferase also activates, by 4'-phosphopantetheinylation, recombinant alpha-aminoadipate reductase (Lys2p) from Candida albicans, a key enzyme involved in lysine biosynthesis.

  5. Measurement of Nonribosomal Peptide Synthetase Adenylation Domain Activity Using a Continuous Hydroxylamine Release Assay.

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    Duckworth, Benjamin P; Wilson, Daniel J; Aldrich, Courtney C

    2016-01-01

    Adenylation is a crucial enzymatic process in the biosynthesis of nonribosomal peptide synthetase (NRPS) derived natural products. Adenylation domains are considered the gatekeepers of NRPSs since they select, activate, and load the carboxylic acid substrate onto a downstream peptidyl carrier protein (PCP) domain of the NRPS. We describe a coupled continuous kinetic assay for NRPS adenylation domains that substitutes the PCP domain with hydroxylamine as the acceptor molecule. The pyrophosphate released from the first-half reaction is then measured using a two-enzyme coupling system, which detects conversion of the chromogenic substrate 7-methylthioguanosine (MesG) to 7-methylthioguanine. From profiling substrate specificity of unknown or engineered adenylation domains to studying chemical inhibition of adenylating enzymes, this robust assay will be of widespread utility in the broad field NRPS enzymology.

  6. SANDPUMA: ensemble predictions of nonribosomal peptide chemistry reveal biosynthetic diversity across Actinobacteria.

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    Chevrette, Marc G; Aicheler, Fabian; Kohlbacher, Oliver; Currie, Cameron R; Medema, Marnix H

    2017-10-15

    Nonribosomally synthesized peptides (NRPs) are natural products with widespread applications in medicine and biotechnology. Many algorithms have been developed to predict the substrate specificities of nonribosomal peptide synthetase adenylation (A) domains from DNA sequences, which enables prioritization and dereplication, and integration with other data types in discovery efforts. However, insufficient training data and a lack of clarity regarding prediction quality have impeded optimal use. Here, we introduce prediCAT, a new phylogenetics-inspired algorithm, which quantitatively estimates the degree of predictability of each A-domain. We then systematically benchmarked all algorithms on a newly gathered, independent test set of 434 A-domain sequences, showing that active-site-motif-based algorithms outperform whole-domain-based methods. Subsequently, we developed SANDPUMA, a powerful ensemble algorithm, based on newly trained versions of all high-performing algorithms, which significantly outperforms individual methods. Finally, we deployed SANDPUMA in a systematic investigation of 7635 Actinobacteria genomes, suggesting that NRP chemical diversity is much higher than previously estimated. SANDPUMA has been integrated into the widely used antiSMASH biosynthetic gene cluster analysis pipeline and is also available as an open-source, standalone tool. SANDPUMA is freely available at https://bitbucket.org/chevrm/sandpuma and as a docker image at https://hub.docker.com/r/chevrm/sandpuma/ under the GNU Public License 3 (GPL3). chevrette@wisc.edu or marnix.medema@wur.nl. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  7. Bioactivities by a crude extract from the Greenlandic Pseudomonas sp. In5 involves the nonribosomal peptides, nunamycin and nunapeptin

    DEFF Research Database (Denmark)

    Frydenlund Michelsen, Charlotte; Jensen, Helle; Venditto, Vincent J.

    2015-01-01

    Bioactive microbial metabolites provide a successful source of novel compounds with pharmaceutical potentials. The bacterium Pseudomonas sp. In5 is a biocontrol strain isolated from a plant disease suppressive soil in Greenland, which produces two antimicrobial nonribosomal peptides (NRPs), nunap......), nunapeptin and nunamycin. In this study, we used in vitro antimicrobial and anticancer bioassays to evaluate the potential bioactivities of both a crude extract derived from Pseudomonas sp. In5 and NRPs purified from the crude extract....

  8. Diversity of Nonribosomal Peptide Synthetases Involved in the Biosynthesis of Lipopeptide Biosurfactants

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    Niran Roongsawang

    2010-12-01

    Full Text Available Lipopeptide biosurfactants (LPBSs consist of a hydrophobic fatty acid portion linked to a hydrophilic peptide chain in the molecule. With their complex and diverse structures, LPBSs exhibit various biological activities including surface activity as well as anti-cellular and anti-enzymatic activities. LPBSs are also involved in multi-cellular behaviors such as swarming motility and biofilm formation. Among the bacterial genera, Bacillus (Gram-positive and Pseudomonas (Gram-negative have received the most attention because they produce a wide range of effective LPBSs that are potentially useful for agricultural, chemical, food, and pharmaceutical industries. The biosynthetic mechanisms and gene regulation systems of LPBSs have been extensively analyzed over the last decade. LPBSs are generally synthesized in a ribosome-independent manner with megaenzymes called nonribosomal peptide synthetases (NRPSs. Production of active‑form NRPSs requires not only transcriptional induction and translation but also post‑translational modification and assemblage. The accumulated knowledge reveals the versatility and evolutionary lineage of the NRPSs system. This review provides an overview of the structural and functional diversity of LPBSs and their different biosynthetic mechanisms in Bacillus and Pseudomonas, including both typical and unique systems. Finally, successful genetic engineering of NRPSs for creating novel lipopeptides is also discussed.

  9. Optimization of nonribosomal peptides production by a psychrotrophic fungus: Trichoderma velutinum ACR-P1.

    Science.gov (United States)

    Sharma, Richa; Singh, Varun P; Singh, Deepika; Yusuf, Farnaz; Kumar, Anil; Vishwakarma, Ram A; Chaubey, Asha

    2016-11-01

    Trichoderma is an anamorphic filamentous fungal genus with immense potential for production of small valuable secondary metabolites with indispensable biological activities. Microbial dynamics of a psychrotrophic strain Trichoderma velutinum ACR-P1, isolated from unexplored niches of the Shiwalik region, bestowed with rich biodiversity of microflora, was investigated for production of nonribosomal peptides (NRPs) by metabolite profiling by intact-cell mass spectrometry (ICMS) employing matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometer. Being the first report on NRPs production by T. velutinum, studies on optimization of growth conditions by Response Surface Methodology (RSM) for production of NRPs by ACR-P1 was carried out strategically. Multifold enhancement in the yield of NRPs belonging to subfamily SF4 with medium chain of amino acid residues having m/z 1437.9, 1453.9, and 1452.0 at pH 5.9 at 20 °C and of subfamily SF1 with long-chain amino acid residues having m/z 1770.2, 1784.2, 1800.1, 1802.1, and 1815.1 was achieved at pH 7.0 at 25 °C. Complexities of natural mixtures were thus considerably reduced under respective optimized culture conditions accelerating the production of novel microbial natural products by saving time and resources.

  10. SCREENING OF ANTIMICROBIAL ACTIVITY AND GENES CODING POLYKETIDE SYNTHETASE AND NONRIBOSOMAL PEPTIDE SYNTHETASE OF ACTINOMYCETE ISOLATES

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    Silvia Kovácsová

    2013-12-01

    Full Text Available The aim of this study was to observe antimicrobial activity using agar plate diffusion method and screening genes coding polyketide synthetase (PKS-I and nonribosomal peptide synthetase (NRPS from actinomycetes. A total of 105 actinomycete strains were isolated from arable soil. Antimicrobial activity was demonstrated at 54 strains against at least 1 of total 12 indicator organisms. Antifungal properties were recorded more often than antibacterial properties. The presence of PKS-I and NRPS genes were founded at 61 of total 105 strains. The number of strains with mentioned biosynthetic enzyme gene fragments matching the anticipated length were 19 (18% and 50 (47% respectively. Overall, five actinomycete strains carried all the biosynthetical genes, yet no antimicrobial activity was found against any of tested pathogens. On the other hand, twenty-one strains showed antimicrobial activity even though we were not able to amplify any of the PKS or NRPS genes from them. Combination of the two methods showed broad-spectrum antimicrobial activity of actinomycetes isolated from arable soil, which indicate that actinomycetes are valuable reservoirs of novel bioactive compounds.

  11. Characterization of the product of a nonribosomal peptide synthetase-like (NRPS-like) gene using the doxycycline dependent Tet-on system in Aspergillus terreus.

    Science.gov (United States)

    Sun, Wei-Wen; Guo, Chun-Jun; Wang, Clay C C

    2016-04-01

    Genome sequencing of the fungus Aspergillus terreus uncovered a number of silent core structural biosynthetic genes encoding enzymes presumed to be involved in the production of cryptic secondary metabolites. There are five nonribosomal peptide synthetase (NRPS)-like genes with the predicted A-T-TE domain architecture within the A. terreus genome. Among the five genes, only the product of pgnA remains unknown. The Tet-on system is an inducible, tunable and metabolism-independent expression system originally developed for Aspergillus niger. Here we report the adoption of the Tet-on system as an effective gene activation tool in A. terreus. Application of this system in A. terreus allowed us to uncover the product of the cryptic NRPS-like gene, pgnA. Furthermore expression of pgnA in the heterologous Aspergillus nidulans host suggested that the pgnA gene alone is necessary for phenguignardic acid (1) biosynthesis. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Comparative analysis of oligonucleotide primers for high-throughput screening of genes encoding adenylation domains of nonribosomal peptide synthetases in actinomycetes

    Czech Academy of Sciences Publication Activity Database

    Bakal, Tomáš; Goo, K.-S.; Najmanová, Lucie; Plháčková, Kamila; Kadlčík, Stanislav; Ulanová, Dana

    2015-01-01

    Roč. 108, č. 5 (2015), s. 1267-1274 ISSN 0003-6072 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61388971 Keywords : Nonribosomal peptide synthetase * Adenylation domain * Actinomycetes Subject RIV: EE - Microbiology, Virology Impact factor: 1.944, year: 2015

  13. The expression of selected non-ribosomal peptide synthetases in Aspergillus fumigatus is controlled by the availability of free iron.

    Science.gov (United States)

    Reiber, Kathrin; Reeves, Emer P; Neville, Claire M; Winkler, Robert; Gebhardt, Peter; Kavanagh, Kevin; Doyle, Sean

    2005-07-01

    Three non-ribosomal peptide synthetase genes, termed sidD, sidC and sidE, have been identified in Aspergillus fumigatus. Gene expression analysis by RT-PCR confirms that expression of both sidD and C was reduced by up to 90% under iron-replete conditions indicative of a likely role in siderophore biosynthesis. SidE expression was less sensitive to iron levels. In addition, two proteins purified from mycelia grown under iron-limiting conditions corresponded to SidD ( approximately 200 kDa) and SidC (496 kDa) as determined by MALDI ToF peptide mass fingerprinting and MALDI LIFT-ToF/ToF. Siderophore synthetases are unique in bacteria and fungi and represent an attractive target for antimicrobial chemotherapy.

  14. Structure Elucidation and Activity of Kolossin A, the D-/L-Pentadecapeptide Product of a Giant Nonribosomal Peptide Synthetase.

    Science.gov (United States)

    Bode, Helge B; Brachmann, Alexander O; Jadhav, Kirtikumar B; Seyfarth, Lydia; Dauth, Christina; Fuchs, Sebastian W; Kaiser, Marcel; Waterfield, Nick R; Sack, Holger; Heinemann, Stefan H; Arndt, Hans-Dieter

    2015-08-24

    The largest continuous bacterial nonribosomal peptide synthetase discovered so far is described. It consists of 15 consecutive modules arising from an uninterrupted, fully functional gene in the entomopathogenic bacterium Photorhabdus luminescens. The identification of its cryptic biosynthesis product was achieved by using a combination of genome analysis, promoter exchange, isotopic labeling experiments, and total synthesis of a focused collection of peptide candidates. Although it belongs to the growing class of D-/ L-peptide natural products, the encoded metabolite kolossin A was found to be largely devoid of antibiotic activity and is likely involved in interspecies communication. A stereoisomer of this peculiar natural product displayed high activity against Trypanosoma brucei rhodesiense, a recalcitrant parasite that causes the deadly disease African sleeping sickness. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A genome-wide analysis of nonribosomal peptide synthetase gene clusters and their peptides in a Planktothrix rubescens strain

    Directory of Open Access Journals (Sweden)

    Nederbragt Alexander J

    2009-08-01

    Full Text Available Abstract Background Cyanobacteria often produce several different oligopeptides, with unknown biological functions, by nonribosomal peptide synthetases (NRPS. Although some cyanobacterial NRPS gene cluster types are well described, the entire NRPS genomic content within a single cyanobacterial strain has never been investigated. Here we have combined a genome-wide analysis using massive parallel pyrosequencing ("454" and mass spectrometry screening of oligopeptides produced in the strain Planktothrix rubescens NIVA CYA 98 in order to identify all putative gene clusters for oligopeptides. Results Thirteen types of oligopeptides were uncovered by mass spectrometry (MS analyses. Microcystin, cyanopeptolin and aeruginosin synthetases, highly similar to already characterized NRPS, were present in the genome. Two novel NRPS gene clusters were associated with production of anabaenopeptins and microginins, respectively. Sequence-depth of the genome and real-time PCR data revealed three copies of the microginin gene cluster. Since NRPS gene cluster candidates for microviridin and oscillatorin synthesis could not be found, putative (gene encoded precursor peptide sequences to microviridin and oscillatorin were found in the genes mdnA and oscA, respectively. The genes flanking the microviridin and oscillatorin precursor genes encode putative modifying enzymes of the precursor oligopeptides. We therefore propose ribosomal pathways involving modifications and cyclisation for microviridin and oscillatorin. The microviridin, anabaenopeptin and cyanopeptolin gene clusters are situated in close proximity to each other, constituting an oligopeptide island. Conclusion Altogether seven nonribosomal peptide synthetase (NRPS gene clusters and two gene clusters putatively encoding ribosomal oligopeptide biosynthetic pathways were revealed. Our results demonstrate that whole genome shotgun sequencing combined with MS-directed determination of oligopeptides successfully

  16. Discovery Strategies of Bioactive Compounds Synthesized by Nonribosomal Peptide Synthetases and Type-I Polyketide Synthases Derived from Marine Microbiomes

    Science.gov (United States)

    Amoutzias, Grigoris D.; Chaliotis, Anargyros; Mossialos, Dimitris

    2016-01-01

    Considering that 70% of our planet’s surface is covered by oceans, it is likely that undiscovered biodiversity is still enormous. A large portion of marine biodiversity consists of microbiomes. They are very attractive targets of bioprospecting because they are able to produce a vast repertoire of secondary metabolites in order to adapt in diverse environments. In many cases secondary metabolites of pharmaceutical and biotechnological interest such as nonribosomal peptides (NRPs) and polyketides (PKs) are synthesized by multimodular enzymes named nonribosomal peptide synthetases (NRPSes) and type-I polyketide synthases (PKSes-I), respectively. Novel findings regarding the mechanisms underlying NRPS and PKS evolution demonstrate how microorganisms could leverage their metabolic potential. Moreover, these findings could facilitate synthetic biology approaches leading to novel bioactive compounds. Ongoing advances in bioinformatics and next-generation sequencing (NGS) technologies are driving the discovery of NRPs and PKs derived from marine microbiomes mainly through two strategies: genome-mining and metagenomics. Microbial genomes are now sequenced at an unprecedented rate and this vast quantity of biological information can be analyzed through genome mining in order to identify gene clusters encoding NRPSes and PKSes of interest. On the other hand, metagenomics is a fast-growing research field which directly studies microbial genomes and their products present in marine environments using culture-independent approaches. The aim of this review is to examine recent developments regarding discovery strategies of bioactive compounds synthesized by NRPS and type-I PKS derived from marine microbiomes and to highlight the vast diversity of NRPSes and PKSes present in marine environments by giving examples of recently discovered bioactive compounds. PMID:27092515

  17. Discovery Strategies of Bioactive Compounds Synthesized by Nonribosomal Peptide Synthetases and Type-I Polyketide Synthases Derived from Marine Microbiomes

    Directory of Open Access Journals (Sweden)

    Grigoris D. Amoutzias

    2016-04-01

    Full Text Available Considering that 70% of our planet’s surface is covered by oceans, it is likely that undiscovered biodiversity is still enormous. A large portion of marine biodiversity consists of microbiomes. They are very attractive targets of bioprospecting because they are able to produce a vast repertoire of secondary metabolites in order to adapt in diverse environments. In many cases secondary metabolites of pharmaceutical and biotechnological interest such as nonribosomal peptides (NRPs and polyketides (PKs are synthesized by multimodular enzymes named nonribosomal peptide synthetases (NRPSes and type-I polyketide synthases (PKSes-I, respectively. Novel findings regarding the mechanisms underlying NRPS and PKS evolution demonstrate how microorganisms could leverage their metabolic potential. Moreover, these findings could facilitate synthetic biology approaches leading to novel bioactive compounds. Ongoing advances in bioinformatics and next-generation sequencing (NGS technologies are driving the discovery of NRPs and PKs derived from marine microbiomes mainly through two strategies: genome-mining and metagenomics. Microbial genomes are now sequenced at an unprecedented rate and this vast quantity of biological information can be analyzed through genome mining in order to identify gene clusters encoding NRPSes and PKSes of interest. On the other hand, metagenomics is a fast-growing research field which directly studies microbial genomes and their products present in marine environments using culture-independent approaches. The aim of this review is to examine recent developments regarding discovery strategies of bioactive compounds synthesized by NRPS and type-I PKS derived from marine microbiomes and to highlight the vast diversity of NRPSes and PKSes present in marine environments by giving examples of recently discovered bioactive compounds.

  18. Publisher Correction: Resistance to nonribosomal peptide antibiotics mediated by D-stereospecific peptidases.

    Science.gov (United States)

    Li, Yong-Xin; Zhong, Zheng; Hou, Peng; Zhang, Wei-Peng; Qian, Pei-Yuan

    2018-03-07

    In the version of this article originally published, the links and files for the Supplementary Information, including Supplementary Tables 1-5, Supplementary Figures 1-25, Supplementary Note, Supplementary Datasets 1-4 and the Life Sciences Reporting Summary, were missing in the HTML. The error has been corrected in the HTML version of this article.

  19. Mining for Nonribosomal Peptide Synthetase and Polyketide Synthase Genes Revealed a High Level of Diversity in the Sphagnum Bog Metagenome.

    Science.gov (United States)

    Müller, Christina A; Oberauner-Wappis, Lisa; Peyman, Armin; Amos, Gregory C A; Wellington, Elizabeth M H; Berg, Gabriele

    2015-08-01

    Sphagnum bog ecosystems are among the oldest vegetation forms harboring a specific microbial community and are known to produce an exceptionally wide variety of bioactive substances. Although the Sphagnum metagenome shows a rich secondary metabolism, the genes have not yet been explored. To analyze nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), the diversity of NRPS and PKS genes in Sphagnum-associated metagenomes was investigated by in silico data mining and sequence-based screening (PCR amplification of 9,500 fosmid clones). The in silico Illumina-based metagenomic approach resulted in the identification of 279 NRPSs and 346 PKSs, as well as 40 PKS-NRPS hybrid gene sequences. The occurrence of NRPS sequences was strongly dominated by the members of the Protebacteria phylum, especially by species of the Burkholderia genus, while PKS sequences were mainly affiliated with Actinobacteria. Thirteen novel NRPS-related sequences were identified by PCR amplification screening, displaying amino acid identities of 48% to 91% to annotated sequences of members of the phyla Proteobacteria, Actinobacteria, and Cyanobacteria. Some of the identified metagenomic clones showed the closest similarity to peptide synthases from Burkholderia or Lysobacter, which are emerging bacterial sources of as-yet-undescribed bioactive metabolites. This report highlights the role of the extreme natural ecosystems as a promising source for detection of secondary compounds and enzymes, serving as a source for biotechnological applications. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  20. Structures of a Nonribosomal Peptide Synthetase Module Bound to MbtH-like Proteins Support a Highly Dynamic Domain Architecture

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Bradley R.; Drake, Eric J.; Shi, Ce; Aldrich, Courtney C.; Gulick, Andrew M. (UMM); (HWMRI)

    2016-09-05

    Nonribosomal peptide synthetases (NRPSs) produce a wide variety of peptide natural products. During synthesis, the multidomain NRPSs act as an assembly line, passing the growing product from one module to the next. Each module generally consists of an integrated peptidyl carrier protein, an amino acid-loading adenylation domain, and a condensation domain that catalyzes peptide bond formation. Some adenylation domains interact with small partner proteins called MbtH-like proteins (MLPs) that enhance solubility or activity. A structure of an MLP bound to an adenylation domain has been previously reported using a truncated adenylation domain, precluding any insight that might be derived from understanding the influence of the MLP on the intact adenylation domain or on the dynamics of the entire NRPS module. Here, we present the structures of the full-length NRPS EntF bound to the MLPs from Escherichia coli and Pseudomonas aeruginosa. These new structures, along with biochemical and bioinformatics support, further elaborate the residues that define the MLP-adenylation domain interface. Additionally, the structures highlight the dynamic behavior of NRPS modules, including the module core formed by the adenylation and condensation domains as well as the orientation of the mobile thioesterase domain.

  1. Structural basis of the interaction of MbtH-like proteins, putative regulators of nonribosomal peptide biosynthesis, with adenylating enzymes.

    Science.gov (United States)

    Herbst, Dominik A; Boll, Björn; Zocher, Georg; Stehle, Thilo; Heide, Lutz

    2013-01-18

    The biosynthesis of nonribosomally formed peptides (NRPs), which include important antibiotics such as vancomycin, requires the activation of amino acids through adenylate formation. The biosynthetic gene clusters of NRPs frequently contain genes for small, so-called MbtH-like proteins. Recently, it was discovered that these MbtH-like proteins are required for some of the adenylation reactions in NRP biosynthesis, but the mechanism of their interaction with the adenylating enzymes has remained unknown. In this study, we determined the structure of SlgN1, a 3-methylaspartate-adenylating enzyme involved in the biosynthesis of the hybrid polyketide/NRP antibiotic streptolydigin. SlgN1 contains an MbtH-like domain at its N terminus, and our analysis defines the parameters required for an interaction between MbtH-like domains and an adenylating enzyme. Highly conserved tryptophan residues of the MbtH-like domain critically contribute to this interaction. Trp-25 and Trp-35 form a cleft on the surface of the MbtH-like domain, which accommodates the alanine side chain of Ala-433 of the adenylating domain. Mutation of Ala-433 to glutamate abolished the activity of SlgN1. Mutation of Ser-23 of the MbtH-like domain to tyrosine resulted in strongly reduced activity. However, the activity of this S23Y mutant could be completely restored by addition of the intact MbtH-like protein CloY from another organism. This suggests that the interface found in the structure of SlgN1 is the genuine interface between MbtH-like proteins and adenylating enzymes.

  2. Original Researc Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    Practices. Problems. Supervision. Primary School. *Corresponding Author: Asrat Dagnew. E-mail: asratboza@yahoo.com tructional support. The relevant and ... vision is one of indispensable system pment. Supervision is a system of that directly concerned on the aff members in a school or other. Original Research ...

  3. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    language in social interaction( Anto et al., 2012; Tessema et al., 2012). While such ..... 10 items on a five-point Likert scale originally developed by Benard et al. (2007). ..... self-confidence, and hold down their anxiety levels. In this study ...

  4. Inhibition of Grape Crown Gall by Agrobacterium vitis F2/5 Requires Two Nonribosomal Peptide Synthetases and One Polyketide Synthase.

    Science.gov (United States)

    Zheng, Desen; Burr, Thomas J

    2016-02-01

    Agrobacterium vitis nontumorigenic strain F2/5 is able to inhibit crown gall disease on grapevines. The mechanism of grape tumor inhibition (GTI) by F2/5 has not been fully determined. In this study, we demonstrate that two nonribosomal peptide synthetase (NRPS) genes (F-avi3342 and F-avi5730) and one polyketide synthase gene (F-avi4330) are required for GTI. Knockout of any one of them resulted in F/25 losing GTI capacity. We previously reported that F-avi3342 and F-avi4330 but not F-avi5730 are required for induction of grape tissue necrosis and tobacco hypersensitive response. F-avi5730 is predicted to encode a single modular NRPS. It is located in a cluster that is homologous to the siderophore vicibactin biosynthesis locus in Rhizobium species. Individual disruption of F-avi5730 and two immediate downstream genes, F-avi5731 and F-avi5732, all resulted in reduced siderophore production; however, only F-avi5730 was found to be required for GTI. Complemented F-avi5730 mutant (ΔF-avi5730(+)) restored a wild-type level of GTI activity. It was determined that, over time, populations of ΔF-avi4330, ΔF-avi3342, and ΔF-avi5730 at inoculated wound sites on grapevine did not differ from those of ΔF-avi5730(+) indicating that loss of GTI was not due to reduced colonization of wound sites by mutants.

  5. Structure determination of the functional domain interaction of a chimeric nonribosomal peptide synthetase from a challenging crystal with noncrystallographic translational symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Sundlov, Jesse A.; Gulick, Andrew M., E-mail: gulick@hwi.buffalo.edu [University at Buffalo, 700 Ellicott Street, Buffalo, NY 14203 (United States)

    2013-08-01

    The structure of the functional interaction of NRPS adenylation and carrier protein domains, trapped with a mechanism-based inhibitor, is described. Crystals exhibit translational non-crystallographic symmetry, which challenged structure determination and refinement. The nonribosomal peptide synthetases (NRPSs) are a family of modular proteins that contain multiple catalytic domains joined in a single protein. Together, these domains work to produce chemically diverse peptides, including compounds with antibiotic activity or that play a role in iron acquisition. Understanding the structural mechanisms that govern the domain interactions has been a long-standing goal. During NRPS synthesis, amino-acid substrates are loaded onto integrated carrier protein domains through the activity of NRPS adenylation domains. The structures of two adenylation domain–carrier protein domain complexes have recently been determined in an effort that required the use of a mechanism-based inhibitor to trap the domain interaction. Here, the continued analysis of these proteins is presented, including a higher resolution structure of an engineered di-domain protein containing the EntE adenylation domain fused with the carrier protein domain of its partner EntB. The protein crystallized in a novel space group in which molecular replacement and refinement were challenged by noncrystallographic pseudo-translational symmetry. The structure determination and how the molecular packing impacted the diffraction intensities are reported. Importantly, the structure illustrates that in this new crystal form the functional interface between the adenylation domain and the carrier protein domain remains the same as that observed previously. At a resolution that allows inclusion of water molecules, additional interactions are observed between the two protein domains and between the protein and its ligands. In particular, a highly solvated region that surrounds the carrier protein cofactor is described.

  6. Structure determination of the functional domain interaction of a chimeric nonribosomal peptide synthetase from a challenging crystal with noncrystallographic translational symmetry

    International Nuclear Information System (INIS)

    Sundlov, Jesse A.; Gulick, Andrew M.

    2013-01-01

    The structure of the functional interaction of NRPS adenylation and carrier protein domains, trapped with a mechanism-based inhibitor, is described. Crystals exhibit translational non-crystallographic symmetry, which challenged structure determination and refinement. The nonribosomal peptide synthetases (NRPSs) are a family of modular proteins that contain multiple catalytic domains joined in a single protein. Together, these domains work to produce chemically diverse peptides, including compounds with antibiotic activity or that play a role in iron acquisition. Understanding the structural mechanisms that govern the domain interactions has been a long-standing goal. During NRPS synthesis, amino-acid substrates are loaded onto integrated carrier protein domains through the activity of NRPS adenylation domains. The structures of two adenylation domain–carrier protein domain complexes have recently been determined in an effort that required the use of a mechanism-based inhibitor to trap the domain interaction. Here, the continued analysis of these proteins is presented, including a higher resolution structure of an engineered di-domain protein containing the EntE adenylation domain fused with the carrier protein domain of its partner EntB. The protein crystallized in a novel space group in which molecular replacement and refinement were challenged by noncrystallographic pseudo-translational symmetry. The structure determination and how the molecular packing impacted the diffraction intensities are reported. Importantly, the structure illustrates that in this new crystal form the functional interface between the adenylation domain and the carrier protein domain remains the same as that observed previously. At a resolution that allows inclusion of water molecules, additional interactions are observed between the two protein domains and between the protein and its ligands. In particular, a highly solvated region that surrounds the carrier protein cofactor is described

  7. The Insect Pathogen Serratia marcescens Db10 Uses a Hybrid Non-Ribosomal Peptide Synthetase-Polyketide Synthase to Produce the Antibiotic Althiomycin

    Science.gov (United States)

    Challis, Gregory L.; Stanley-Wall, Nicola R.; Coulthurst, Sarah J.

    2012-01-01

    There is a continuing need to discover new bioactive natural products, such as antibiotics, in genetically-amenable micro-organisms. We observed that the enteric insect pathogen, Serratia marcescens Db10, produced a diffusible compound that inhibited the growth of Bacillis subtilis and Staphyloccocus aureus. Mapping the genetic locus required for this activity revealed a putative natural product biosynthetic gene cluster, further defined to a six-gene operon named alb1–alb6. Bioinformatic analysis of the proteins encoded by alb1–6 predicted a hybrid non-ribosomal peptide synthetase-polyketide synthase (NRPS-PKS) assembly line (Alb4/5/6), tailoring enzymes (Alb2/3) and an export/resistance protein (Alb1), and suggested that the machinery assembled althiomycin or a related molecule. Althiomycin is a ribosome-inhibiting antibiotic whose biosynthetic machinery had been elusive for decades. Chromatographic and spectroscopic analyses confirmed that wild type S. marcescens produced althiomycin and that production was eliminated on disruption of the alb gene cluster. Construction of mutants with in-frame deletions of specific alb genes demonstrated that Alb2–Alb5 were essential for althiomycin production, whereas Alb6 was required for maximal production of the antibiotic. A phosphopantetheinyl transferase enzyme required for althiomycin biosynthesis was also identified. Expression of Alb1, a predicted major facilitator superfamily efflux pump, conferred althiomycin resistance on another, sensitive, strain of S. marcescens. This is the first report of althiomycin production outside of the Myxobacteria or Streptomyces and paves the way for future exploitation of the biosynthetic machinery, since S. marcescens represents a convenient and tractable producing organism. PMID:23028578

  8. Inactivation of the Major Hemolysin Gene Influences Expression of the Nonribosomal Peptide Synthetase Gene swrA in the Insect Pathogen Serratia sp. Strain SCBI.

    Science.gov (United States)

    Petersen, Lauren M; LaCourse, Kaitlyn; Schöner, Tim A; Bode, Helge; Tisa, Louis S

    2017-11-01

    Hemolysins are important virulence factors for many bacterial pathogens, including Serratia marcescens The role of the major hemolysin gene in the insect pathogen Serratia sp. strain SCBI was investigated using both forward and reverse-genetics approaches. Introduction of the major hemolysin gene into Escherichia coli resulted in a gain of both virulence and hemolytic activity. Inactivation of this hemolysin in Serratia sp. SCBI resulted in a loss of hemolysis but did not attenuate insecticidal activity. Unexpectedly, inactivation of the hemolysin gene in Serratia sp. SCBI resulted in significantly increased motility and increased antimicrobial activity. Reverse transcription-quantitative PCR (qRT-PCR) analysis of mutants with a disrupted hemolysin gene showed a dramatic increase in mRNA levels of a nonribosomal peptide synthetase gene, swrA , which produces the surfactant serrawettin W2. Mutation of the swrA gene in Serratia sp. SCBI resulted in highly varied antibiotic activity, motility, virulence, and hemolysis phenotypes that were dependent on the site of disruption within this 17.75-kb gene. When introduced into E. coli , swrA increases rates of motility and confers antimicrobial activity. While it is unclear how inactivation of the major hemolysin gene influences the expression of swrA , these results suggest that swrA plays an important role in motility and antimicrobial activity in Serratia sp. SCBI. IMPORTANCE The opportunistic Gram-negative bacteria of the genus Serratia are widespread in the environment and can cause human illness. A comparative genomics analysis between Serratia marcescens and a new Serratia species from South Africa, termed Serratia sp. strain SCBI, shows that these two organisms are closely related but differ in pathogenesis. S. marcescens kills Caenorhabditis nematodes, while Serratia sp. SCBI is not harmful and forms a beneficial association with them. This distinction presented the opportunity to investigate potential differences

  9. Genome based analysis of type-I polyketide synthase and nonribosomal peptide synthetase gene clusters in seven strains of five representative Nocardia species.

    Science.gov (United States)

    Komaki, Hisayuki; Ichikawa, Natsuko; Hosoyama, Akira; Takahashi-Nakaguchi, Azusa; Matsuzawa, Tetsuhiro; Suzuki, Ken-ichiro; Fujita, Nobuyuki; Gonoi, Tohru

    2014-04-30

    Actinobacteria of the genus Nocardia usually live in soil or water and play saprophytic roles, but they also opportunistically infect the respiratory system, skin, and other organs of humans and animals. Primarily because of the clinical importance of the strains, some Nocardia genomes have been sequenced, and genome sequences have accumulated. Genome sizes of Nocardia strains are similar to those of Streptomyces strains, the producers of most antibiotics. In the present work, we compared secondary metabolite biosynthesis gene clusters of type-I polyketide synthase (PKS-I) and nonribosomal peptide synthetase (NRPS) among genomes of representative Nocardia species/strains based on domain organization and amino acid sequence homology. Draft genome sequences of Nocardia asteroides NBRC 15531(T), Nocardia otitidiscaviarum IFM 11049, Nocardia brasiliensis NBRC 14402(T), and N. brasiliensis IFM 10847 were read and compared with published complete genome sequences of Nocardia farcinica IFM 10152, Nocardia cyriacigeorgica GUH-2, and N. brasiliensis HUJEG-1. Genome sizes are as follows: N. farcinica, 6.0 Mb; N. cyriacigeorgica, 6.2 Mb; N. asteroides, 7.0 Mb; N. otitidiscaviarum, 7.8 Mb; and N. brasiliensis, 8.9 - 9.4 Mb. Predicted numbers of PKS-I, NRPS, and PKS-I/NRPS hybrid clusters ranged between 4-11, 7-13, and 1-6, respectively, depending on strains, and tended to increase with increasing genome size. Domain and module structures of representative or unique clusters are discussed in the text. We conclude the following: 1) genomes of Nocardia strains carry as many PKS-I and NRPS gene clusters as those of Streptomyces strains, 2) the number of PKS-I and NRPS gene clusters in Nocardia strains varies substantially depending on species, and N. brasiliensis strains carry the largest numbers of clusters among the species studied, 3) the seven Nocardia strains studied in the present work have seven common PKS-I and/or NRPS clusters, some of whose products are yet to be studied

  10. Non-ribosomal peptide synthetases

    Indian Academy of Sciences (India)

    2017-01-19

    Jan 19, 2017 ... knowledge of their gene cluster architecture and tailoring enzymes have helped in the in silico genetic ..... The predictive power of the bioinformatics sequence analy- .... identified these motifs manually, though NaPDoS, anti-.

  11. Original Misunderstanding

    Science.gov (United States)

    Holtzman, Alexander

    2009-01-01

    Humorist Josh Billings quipped, "About the most originality that any writer can hope to achieve honestly is to steal with good judgment." Billings was harsh in his view of originality, but his critique reveals a tension faced by students every time they write a history paper. Research is the essence of any history paper. Especially in high school,…

  12. Original Article

    African Journals Online (AJOL)

    Administratör

    Original Article. Prevalence of Gall Bladder Stones among Type 2 Diabetic ... Increasing age, female gender, overweight, familial history of the disease and type 2 diabetes mellitus is all associated ... GBS development in diabetics. An Italian ...

  13. ORIGINAL ARTICLE

    African Journals Online (AJOL)

    User

    UDS Publishers Limited All Right Reserved 2026-6294. ORIGINAL ... Reproductive development and function in human and other ... sulting solution was filtered and left to stand for three days to ..... male rat brain and pituitary. Brain Res 164,.

  14. Original pedagogues

    DEFF Research Database (Denmark)

    Schmidt, Christina Haandbæk

    Original pedagogues Distention between competences and originality By Christina Haandbæk Schmidt, ph. d. student Aarhus University, Denmark This presentation concerns a Ph.D. project (Sept. 2012 –Sept. 2015) about pedagogues in day care facilities and their struggles to develop and retain...... shall argue that it is necessary for the pedagogues to know how they are constituted by the regimes of power on one side and on the other side are forced to create themselves. This knowledge could transform pedagogues into what I suggest calling ‘original pedagogues’, who have an authentic, ethic...... and professional autonomy in exercising judgment concerning pedagogical situations. To understand how pedagogues can struggle the distention between being competent and being original the project draws on both Michel Foucault and Charles Taylor as two incompatible theories on modern identity. The study...

  15. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    ORIGINAL ARTICLES. Illnesses of Herod the Great. Francois P Retief, Johan F G Cilliers. Herod the Great, ldumean by birth, was king ofthe Jews from 40 to 4 BC. An able statesman, builder and warrior, he ruthlessly stamped out all perceived opposition to his rule. His last decade was characterised by vicious strife within ...

  16. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    ORIGINAL ARTICLES. OCCUPATIONAL EXPOSURE OF. INTERNS TO BLOOD IN AN AREA. OF HIGH HIV SEROPREVALENCE. A S Karstaedt, L Pantanowitz. Objective. To determine the epidemiology of work-related exposure to blood among interns. Design. Interns were invited to complete anonymously a questionnaire ...

  17. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    ORIGINAL ARTICLES. References. 1. McCarthy D, Amos A, Zimmet P. The rising global burden of diabetes and its complications: estimates and projections to the year 2010. Diabet Med 1997; 14: suppl 5, Sl-585. 2. Zgibor JC, Songer TJ, Kelsey SF, et al. The association of diabetes specialist care with health care practices ...

  18. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    ORIGINAL ARTICLES. Cost to patients of obtaining treatment for HIV/AIDS in. South Africa. Sydney Rosen, Mpefe Ketlhapile, Ian Sanne, Mary Bachman DeSilva. Background. South Africa is providing antiretroviral (ARV) drugs for HIV I AIDS free of charge in order to increase access for poorer patients and promote ...

  19. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    ORIGINAL ARTICLES could be chosen to link to action policy decisions. In the. Integrated Management of Childhood Illness (IMCI) programme, such a screening test would also remind the health provider to prescribe an iron tonic and to emphasise the importance of a balanced diet. A potential disadvantage of copper ...

  20. Original Article

    African Journals Online (AJOL)

    Arab Journal of Nephrology and Transplantation. 2013 Sep;6(3):153-60. Original Article. AJNT. Abstract. Introduction: Dense Deposit Disease (DDD) is a devastating renal disease that leads to renal failure within. 10 years of diagnosis in about half of affected patients. In this study, we evaluated the relative prevalence and.

  1. ORIGINAL ARTICLE

    African Journals Online (AJOL)

    User

    One of the concerns among mothers for delivery is labor pain. There are various ... Journal of Medical and Biomedical Sciences (2017) 6(2): 11-16. © UDS Publishers ... ORIGINAL ARTICLE ..... effective than a placebo during the first stage of.

  2. Original Article

    African Journals Online (AJOL)

    Pezhman Kharazm

    treatment in 32 patients who were admitted in Shohada-E-Tajrish hospital with final diagnosis of AMI from March 1996 to March 2002. ... of the patient and diagnostic studies and early surgical or non surgical intervention is the most ... operative diagnosis of etiology was based on presence of pulse at the origin of mesenteric.

  3. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    ORIGINAL ARTICLES. References. 1. UNAIDS. Report on the Global HTV/AIDS Epidemic. Geneva: June 2000. 2. Connor E..\\1, Sperling RS, Gelber R. et al. Reduction of maternal-infant transmission of human immunodeficiency virus type 1 with zidovu dine treatment. N Eng! J Med 1994; 331:1173-1180. 3. Undegren ML ...

  4. Original Research

    African Journals Online (AJOL)

    A facility based comparative cross-sectional study ... Health care delivery should consider the desire for children by men and .... Socio-Demographic Characteristics of the .... For substitution, children are an important part of marriage, current child needs sibling, original desires .... does not, the only way to avoid the risk of.

  5. ORIGINAL ARTICLE

    African Journals Online (AJOL)

    User

    source of blood supply whilst in developed countries VNRDs are the major source. This study de- termined and ... UDS Publishers Limited All Right Reserved 2026-6294. ORIGINAL ..... ferral rate of females in comparison to males as pre- .... nors at blood bank of a medical college,. Australia. Med J Armed Forces 61: 131- 4.

  6. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    alternatives to conventional care (homoeopathy, chiropractic, acupuncture, etc.), and also recognise the groundswell of interest in and support for inclusion of benefits for services provided by traditional healers. The transition from the original, relatively restricted approach which was concerned with established, mainstream.

  7. Original contributions

    African Journals Online (AJOL)

    hefere

    Original contributions ... Results suggest that there is a significant positive ... psychological abuse, including economic abuse, intimidation, harassment, stalking, damage ... or maintaining the structure and function of the African home (Alio et al., 2011; Jewkes,. Levin ... Revictimisation occurs due to emotional violence and.

  8. Original Copies

    DEFF Research Database (Denmark)

    Sørensen, Tim Flohr

    2013-01-01

    of similarity by looking at artefactual similarity as the results of prototyping and as a production of simulacra. In this light, the concept of copying turns out to be more than simply a matter of trying to imitate an exotic or prestigious original, and it fundamentally raises the question how different a copy...

  9. ORIGINAL ARTICLE

    African Journals Online (AJOL)

    User

    there are racial and gender differences in the knowledge and awareness of HPV among Guyanese. The study aimed to ... UDS Publishers Limited All Right Reserved 2026-6294. ORIGINAL ... shown that, about 80.0% of women contracted HPV infection before ... 2010), age of initial sexual contact, and lack of symp- toms for ...

  10. Original Thinking

    Directory of Open Access Journals (Sweden)

    Ashok Natarajan

    2012-04-01

    Full Text Available History that comes to us as a chronology of events is really a collective existence that is evolving through several stages to develop Individuality in all members of the society. The human community, nation states, linguistic groups, local castes and classes, and families are the intermediate stages in development of the Individual. The social process moves through phases of survival, growth, development and evolution. In the process it organizes the consciousness of its members at successive levels from social external manners, formed behavior, value-based character and personality to culminate in the development of Individuality. Through this process, society evolves from physicality to Mentality. The power of accomplishment in society and its members develops progressively through stages of skill, capacity, talent, and ability. Original thinking is made possible by the prior development of thinking that organizes facts into information. The immediate result of the last world war was a shift in reliance from physical force and action to mental conception and mental activity on a global scale. At such times no problem need defy solution, if only humanity recognizes the occasion for thinking and Original Thinking. The apparently insoluble problems we confront are an opportunity to formulate a comprehensive theory of social evolution. The immediate possibility is to devise complete solutions to all existing problems, if only we use the right method of thought development.

  11. Quench origins

    International Nuclear Information System (INIS)

    Devred, A.

    1990-03-01

    In this paper, I shall discuss the quench origins. I shall first establish a method of classification and introduce the notions of conductor-limited and energy-deposited quenches. Next the paper will be devoted to the study of conductor-limited quenches, and I shall introduce the notions of plateau and of fraction of short sample. Also the paper will be devoted to the study of energy-deposited quenches, and I shall introduce the notions of training and of minimum energy deposit; I shall then review the possible causes of energy release. Lastly, I shall introduce the notion of operating margin, and I shall indicate how to optimize the operating margin in order to limit the risk of premature quenching. 112 refs., 14 figs

  12. Nonribosomal peptide synthesis in Bacillus subtilis

    NARCIS (Netherlands)

    Duitman, Erwin Hans

    2003-01-01

    Numerous microorganisms, both prokaryotes and eukaryotes, have developed various strategies, which enable them to adapt and survive the often adverse circumstances present in their natural environment ... Zie: Summary and general conclusions

  13. The Origin of Language

    OpenAIRE

    Araki,Naoki

    2018-01-01

    There have been a lot of discussions of the origin of language. Some people think that the origin of words is onomatopoeias. Meanwhile, according to expressive theories, the origin of words and language is the innate cries of pain or pleasure produced by nonhuman animals. Others insist that language originated as a means of communication. Another theory holds that a learned vocalization systems, more like birdsong than innate calls, formed a middle term in language evolution. Others claim tha...

  14. Accounting for Fetal Origins

    DEFF Research Database (Denmark)

    Dalgaard, Carl-Johan Lars; Hansen, Casper Worm; Strulik, Holger

    2017-01-01

    The Fetal Origins hypothesis has received considerable empirical support, both within epidemiology and economics. The present study compares the ability of two rival theoretical frameworks in accounting for the kind of path dependence implied by the Fetal Origins Hypothesis. We argue that while...

  15. Marxismo original e Utopia

    OpenAIRE

    Nildo Viana

    2016-01-01

    O marxismo original – desenvolvido por Marx e Engels – geralmente é contraposto ao socialismo utópico como se fosse uma recusa absoluta e total. O objetivo do artigo é discutir a relação entre o marxismo original e o socialismo utópico e com a utopia. A tese defendida no artigo é a de que o caráter antiutópico do marxismo original é uma simplificação, pois o que ele realiza é uma suplantação do utopismo, o que significa manter os seus elementos positivos e negar os seus elementos negativos. P...

  16. Libertarianism and Original Appropriation

    OpenAIRE

    Dominiak, Łukasz

    2017-01-01

    The article is devoted to the problem of the structure of libertarian theory of justice. It tries to present a map of the main concepts and principles of this theory and to investigate its possible justifications. It explains such fundamental concepts as original appropriation, homesteading, labour theory of property or first possession theory of original appropriation. The article shows merits and drawbacks of alternative libertarian principles of justice in first acquisition and proposes a ...

  17. Origins: science inspires art

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    From 8 December 2011 to 17 February 2012, Geneva University's physics faculty will be holding an exhibition called "L'Origine – un voyage entre la Science et l'Art". Thirty artists from Europe and Africa will be exhibiting their work.   The aim of the exhibition is to take the visitor on an imaginary journey to the origins of mankind and to show how science and art approach the same theme from different angles. The works on display will include pieces of Makonde art, a traditional art form native to Mozambique, created by artists of the Nairucu Arts centre. The cultural programme that will run alongside the exhibition will include lectures on contemporary scientific themes aimed at the general public. Visitors will also have the opportunity to discover "L’Origine", a book of poetry by Beatrice Bressan (Ed. Loreleo, Geneva, 2010), which was awarded the third prize in the “Poeti nella società&...

  18. Origin of solar system

    Energy Technology Data Exchange (ETDEWEB)

    Pokorny, Z.

    1984-01-01

    The generally accepted concept has it that the Sun and the planets originated almost simultaneously from nebula (the nebular hypothesis). It is assumed that the temperature of the nebula decreased in the direction from the centre which led to the segregation of elements and to the different chemical composition of the individual planets. The planets formed either from the gravitational collapse of part of the nebula or by gradual accretion. In the scenario of the origin of the solar system there are many blank spots, namely as concerns the initial stages of development and the period when the formation of the planets had ''almost been completed''.

  19. Origin of solar system

    International Nuclear Information System (INIS)

    Pokorny, Z.

    1984-01-01

    The generally accepted concept has it that the Sun and the planets originated almost simultaneously from nebula (the nebular hypothesis). It is assumed that the temperature of the nebula decreased in the direction from the centre which led to the segregation of elements and to the different chemical composition of the individual planets. The planets formed either from the gravitational collapse of part of the nebula or by gradual accretion. In the scenario of the origin of the solar system there are many blank spots, namely as concerns the initial stages of development and the period when the formation of the planets had ''almost been completed''. (Ha)

  20. Authentic, Original, and Valuable

    DEFF Research Database (Denmark)

    Tupasela, Aaro Mikael; Tamminen, Sakari

    2015-01-01

    The idea of genetic authenticity and origin has been an important issue within genetics for decades for scientific, political, and economic reasons. The question of where species and populations come from, as well as the linking of genetic traits to particular geographical locations, has resurfaced....... Using the case of human and non-human genetics to compare and contrast the various facets associated with genetic identity, we seek to develop a broader picture of the ways in which genetics plays an important role in stabilizing categories of origin....

  1. Towards a Universal Biology: Is the Origin and Evolution of Life Predictable?

    Science.gov (United States)

    Rothschild, Lynn J.

    2017-01-01

    The origin and evolution of life seems an unpredictable oddity, based on the quirks of contingency. Celebrated by the late Stephen Jay Gould in several books, "evolution by contingency" has all the adventure of a thriller, but lacks the predictive power of the physical sciences. Not necessarily so, replied Simon Conway Morris, for convergence reassures us that certain evolutionary responses are replicable. The outcome of this debate is critical to Astrobiology. How can we understand where we came from on Earth without prophesy? Further, we cannot design a rational strategy for the search for life elsewhere - or to understand what the future will hold for life on Earth and beyond - without extrapolating from pre-biotic chemistry and evolution. There are several indirect approaches to understanding, and thus describing, what life must be. These include philosophical approaches to defining life (is there even a satisfactory definition of life?), using what we know of physics, chemistry and life to imagine alternate scenarios, using different approaches that life takes as pseudoreplicates (e.g., ribosomal vs non-ribosomal protein synthesis), and experimental approaches to understand the art of the possible. Given that: (1) Life is a process based on physical components rather than simply an object; (2). Life is likely based on organic carbon and needs a solvent for chemistry, most likely water, and (3) Looking for convergence in terrestrial evolution we can predict certain tendencies, if not quite "laws", that provide predictive power. Biological history must obey the laws of physics and chemistry, the principles of natural selection, the constraints of an evolutionary past, genetics, and developmental biology. This amalgam creates a surprising amount of predictive power in the broad outline. Critical is the apparent prevalence of organic chemistry, and uniformity in the universe of the laws of chemistry and physics. Instructive is the widespread occurrence of

  2. On the origin of comets

    Science.gov (United States)

    Mendis, A.; Alfven, H.

    1976-01-01

    Physico-chemical processes leading to the dynamic formation and physical evolution of comets are reviewed in relationship to the various theories that propose solar origins, protoplanetary origins, planetary origins and interstellar origins. Evidence points to the origins of comets by the growth and agglomeration of small particles from gas and dust at very low temperatures at undetermined regions in space.

  3. Headache of cervical origin

    International Nuclear Information System (INIS)

    Burguet, J.L.; Wackenheim, A.

    1984-01-01

    The authors recall cervical etiologies of headache. They distinguish on the one hand the cervico-occipital region with minor and major malformations and acquired lesions, and on the other hand the middle and inferior cervical segment. They also recall the original structuralist analysis of the cervical spine and give the example of the ''cervical triplet''. (orig.) [de

  4. The origins of AIDS

    National Research Council Canada - National Science Library

    Pepin, Jacques

    2011-01-01

    ... urbanisation, prostitution and large-scale colonial medical campaigns intended to eradicate tropical diseases combined to disastrous effect to fuel the spread of the virus from its origins in Léopoldville to the rest of Africa, the Caribbean and ultimately worldwide. This is an essential new perspective on HIV/ AIDS and on the lessons that must be learned if we are to avoi...

  5. The Origin of Species

    NARCIS (Netherlands)

    Darwin, Charles

    2005-01-01

    In The Origin of Species Darwin outlined his theory of evolution, which proposed that species had been evolving and differentiating over time under the influence of natural selection. On its publication it became hugely influential, bringing about a seismic shift in the scientific view of humanitys

  6. Origin (?) of the Universe

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 3. Origin (?) of the Universe The Big Bang. Jayant V Narlikar. Series Article Volume 1 Issue 3 March 1996 pp 6-12. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/03/0006-0012 ...

  7. Original and Derived Judgment

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai Juul; Klein, Peter G.

    and own assets. The entrepreneur's role, then, is to arrange or organize the human and capital assets under his control. We extend this Knightian concept of the firm by developing a theory of delegation under Knightian uncertainty. What we call original judgment belongs exclusively to owners, but owners...

  8. Making cocoa origin traceable

    NARCIS (Netherlands)

    Acierno, Valentina; Alewijn, Martin; Zomer, Paul; Ruth, van Saskia M.

    2018-01-01

    More and more attention is paid to sustainability in the cocoa production. Tools that assist in making sustainable cocoa traceable are therefore welcome. In the present study, the applicability of Flow Infusion-Electrospray Ionization- Mass Spectrometry (FI-ESI-MS) to assess the geographical origin

  9. Origin(?) of the Universe

    Indian Academy of Sciences (India)

    weaknesses of the big bang cosmology, conceptual as well as observational. ... They argue that this event marks the origin of the ... a change of the lowest energy state of matter, normally designated as ... Rapid expansion of this kind produces some lasting effects in the universe. .... This attitude coupled with attempted ...

  10. Conscientiousness: Origins in Childhood?

    Science.gov (United States)

    Eisenberg, Nancy; Duckworth, Angela L.; Spinrad, Tracy L.; Valiente, Carlos

    2014-01-01

    In this review, we evaluate developmental and personality research with the aim of determining whether the personality trait of conscientiousness can be identified in children and adolescents. After concluding that conscientiousness does emerge in childhood, we discuss the developmental origins of conscientiousness with a specific focus on…

  11. 66 ORIGINAL ARTICLE

    African Journals Online (AJOL)

    boaz

    ORIGINAL ARTICLE. AFRICAN JOURNAL OF CLINICAL AND EXPERIMENTAL MICROBIOLOGY JAN 2016 ISBN 1595-689X VOL 17 No.1 ..... WOMEN. Social characteristics. No. examined (n = 310). No. positive. (n=30) (%). Education. Illiterate. Primary. Secondary. Tertiary. Occupation. Civil servant. House wife. Students.

  12. The moon's origins

    International Nuclear Information System (INIS)

    Boss, P.; Benz, W.

    1987-01-01

    Planet formation theory is recalled. The different existing hypothesis on the moon's origins are reviewed also to see how much they are compatible with the planet formation theory. Up to now, the giant impact model seems to be the only model to satisfy all the constraints. Computerized simulation results have been presented in colloquiums and their scenarios are recalled [fr

  13. Symbiotic Origin of Aging.

    Science.gov (United States)

    Greenberg, Edward F; Vatolin, Sergei

    2018-06-01

    Normally aging cells are characterized by an unbalanced mitochondrial dynamic skewed toward punctate mitochondria. Genetic and pharmacological manipulation of mitochondrial fission/fusion cycles can contribute to both accelerated and decelerated cellular or organismal aging. In this work, we connect these experimental data with the symbiotic theory of mitochondrial origin to generate new insight into the evolutionary origin of aging. Mitochondria originated from autotrophic α-proteobacteria during an ancient endosymbiotic event early in eukaryote evolution. To expand beyond individual host cells, dividing α-proteobacteria initiated host cell lysis; apoptosis is a product of this original symbiont cell lytic exit program. Over the course of evolution, the host eukaryotic cell attenuated the harmful effect of symbiotic proto-mitochondria, and modern mitochondria are now functionally interdependent with eukaryotic cells; they retain their own circular genomes and independent replication timing. In nondividing differentiated or multipotent eukaryotic cells, intracellular mitochondria undergo repeated fission/fusion cycles, favoring fission as organisms age. The discordance between cellular quiescence and mitochondrial proliferation generates intracellular stress, eventually leading to a gradual decline in host cell performance and age-related pathology. Hence, aging evolved from a conflict between maintenance of a quiescent, nonproliferative state and the evolutionarily conserved propagation program driving the life cycle of former symbiotic organisms: mitochondria.

  14. Origin of Fire.

    Science.gov (United States)

    Bennett, Ruth, Ed.

    Intended for use with college students, this booklet contains a traditional Hupa story (in Hupa and English) followed by information to aid in a critical literary analysis of the story and topics for student discussion. The introduction explains that "Origin of Fire"--first written down by P.E. Goddard in 1902 and still told by…

  15. Origins of Rolling Friction

    Science.gov (United States)

    Cross, Rod

    2017-01-01

    When a hard object rolls on a soft surface, or vice versa, rolling friction arises from deformation of the soft object or the soft surface. The friction force can be described in terms of an offset in the normal reaction force or in terms of energy loss arising from the deformation. The origin of the friction force itself is not entirely clear. It…

  16. Headache of cervical origin

    Energy Technology Data Exchange (ETDEWEB)

    Burguet, J L; Wackenheim, A

    1984-08-01

    The authors recall cervical etiologies of headache. They distinguish on the one hand the cervico-occipital region with minor and major malformations and acquired lesions, and on the other hand the middle and inferior cervical segment. They also recall the original structuralist analysis of the cervical spine and give the example of the ''cervical triplet''.

  17. About greenhouse effect origins

    International Nuclear Information System (INIS)

    Arrhenius, S.; Chamberlin, Th.; Croll, J.; Fourier, J.; Pouillet, C.; Tyndall, J.

    2009-01-01

    In order to understand and decipher the ecological crisis in progress, an historical prospect of its origins and evolution at the worldwide scale is necessary. This book gathers seven founder articles (including 4 original translations), harbingers of the present day climate change. Written during the 19. century by famous scientists like Joseph Fourier, Claude Pouillet, James Croll, John Tyndall, Svante Arrhenius and Thomas Chamberlin, they relate a century of major progress in the domain of Earth's sciences in praise of these scientists. This book allows to (re)discover these texts: discovery of the greenhouse effect principle (Fourier), determination of solar radiation absorption by the atmosphere (Pouillet), rivalry between the astronomical theory of glacial cycles (Croll) and the carbon dioxide climatic theory (Tyndall), influence of the CO 2 concentration in the atmosphere on the global warming (Arrhenius), and confirmation of the major role of CO 2 in the Earth's temperature regulation (Chamberlin). (J.S.)

  18. Archaeal origin of tubulin

    Directory of Open Access Journals (Sweden)

    Yutin Natalya

    2012-03-01

    Full Text Available Abstract Tubulins are a family of GTPases that are key components of the cytoskeleton in all eukaryotes and are distantly related to the FtsZ GTPase that is involved in cell division in most bacteria and many archaea. Among prokaryotes, bona fide tubulins have been identified only in bacteria of the genus Prosthecobacter. These bacterial tubulin genes appear to have been horizontally transferred from eukaryotes. Here we describe tubulins encoded in the genomes of thaumarchaeota of the genus Nitrosoarchaeum that we denote artubulins Phylogenetic analysis results are compatible with the origin of eukaryotic tubulins from artubulins. These findings expand the emerging picture of the origin of key components of eukaryotic functional systems from ancestral forms that are scattered among the extant archaea. Reviewers This article was reviewed by Gáspár Jékely and J. Peter Gogarten.

  19. Origin of family symmetries

    International Nuclear Information System (INIS)

    Nilles, Hans Peter

    2012-04-01

    Discrete (family) symmetries might play an important role in models of elementary particle physics. We discuss the origin of such symmetries in the framework of consistent ultraviolet completions of the standard model in field and string theory. The symmetries can arise due to special geometrical properties of extra compact dimensions and the localization of fields in this geometrical landscape. We also comment on anomaly constraints for discrete symmetries.

  20. Entrepreneurship: Origins and Returns

    OpenAIRE

    Berglann, Helge; R. Moen, Espen R.; Røed, Knut; Skogstrøm, Jens Fredrik

    2010-01-01

    We examine the origins and outcome of entrepreneurship on the basis of exceptionally comprehensive Norwegian matched worker-firm-owner data. In contrast to most existing studies, our notion of entrepreneurship not only comprises self-employment, but also employment in partly self-owned limited liability firms. Based on this extended entrepreneurship concept, we find that entrepreneurship tends to be profitable. It also raises in-come uncertainty, but the most successful quartile gains much mo...

  1. Origin of family symmetries

    Energy Technology Data Exchange (ETDEWEB)

    Nilles, Hans Peter [Bonn Univ. (Germany). Bethe Center for Theoretical Physics; Bonn Univ. (Germany). Physikalisches Inst.; Ratz, Michael [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Vaudrevange, Patrick K.S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2012-04-15

    Discrete (family) symmetries might play an important role in models of elementary particle physics. We discuss the origin of such symmetries in the framework of consistent ultraviolet completions of the standard model in field and string theory. The symmetries can arise due to special geometrical properties of extra compact dimensions and the localization of fields in this geometrical landscape. We also comment on anomaly constraints for discrete symmetries.

  2. Origin of tektites

    Science.gov (United States)

    O'Keefe, John A.

    1994-01-01

    The origin of tektites has been obscure because of the following dilemma. The application of physical principles to the data available on tektites points strongly to origin from one or more lunar volcanoes; but few glasses of tektite composition have hitherto been reported from the lunar samples. Instead, the lunar silicic glasses consist chiefly of a material very rich in K2O and poor in MgO. The ratio of K2O/MgO is higher in these glasses than in any tektites reported. The solution of the dilemma seems to come from the study of some recently discovered terrestrial deposits of tektite glass with high values of K2O/MgO at the Cretaceous Tertiary boundary. These glasses are found to be very vulnerable to crystallization into sandine or to alteration to smectite. These end products are known and are more abundant than any terrestrial deposits of tektite glass. It seems possible that, in fact, the moon produces tektite glass, mostly of the high K2O-low MgO type; but on Earth these deposits are destroyed. The much less abundant deposits with lower K and higher Mg are observed because they survive. Other objections to the lunar origin hypothesis appear to be answerable.

  3. Origins Space Telescope

    Science.gov (United States)

    Cooray, Asantha; Origins Space Telescope Study Team

    2018-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its spectrographs will enable 3D surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu. This presentation will provide a summary of the OST STDT, our completed first mission concept and an introduction to the second concept that will be studied at the study center in 2018. This presentation will also summarize key science drivers and the key study milestones between 2018 and 2020.

  4. Origin of superelectrons

    International Nuclear Information System (INIS)

    Fukuhara, M.

    1993-01-01

    The origin of superelectrons lies in the atomic nature. Superelectrons are derived from four special electron pair sets of 1s 2 , 2p 6 , 3d 10 , and 4f 14 , which can be represented as 1 S 0 of s-type spin-singlet pairing in the Russel-Saunders term symbol. Tc increases with the increase of the compressive pressure against these spherical electron clouds by the pinch effect due to excess oxygen in cuprate oxide superconductors and the outermost electrons in the superconducting elements, suggesting the increase of the attractive interaction between electrons. (orig.)

  5. The origins of options.

    Science.gov (United States)

    Smaldino, Paul E; Richerson, Peter J

    2012-01-01

    Most research on decision making has focused on how human or animal decision makers choose between two or more options, posed in advance by the researchers. The mechanisms by which options are generated for most decisions, however, are not well understood. Models of sequential search have examined the trade-off between continued exploration and choosing one's current best option, but still cannot explain the processes by which new options are generated. We argue that understanding the origins of options is a crucial but untapped area for decision making research. We explore a number of factors which influence the generation of options, which fall broadly into two categories: psycho-biological and socio-cultural. The former category includes factors such as perceptual biases and associative memory networks. The latter category relies on the incredible human capacity for culture and social learning, which doubtless shape not only our choices but the options available for choice. Our intention is to start a discussion that brings us closer toward understanding the origins of options.

  6. Fever of unknown origin

    International Nuclear Information System (INIS)

    Misaki, Takashi; Matsui, Akira; Tanaka, Fumiko; Okuno, Yoshishige; Mitsumori, Michihide; Torizuka, Tatsurou; Dokoh, Shigeharu; Hayakawa, Katsumi; Shimbo, Shin-ichirou

    1990-01-01

    Gallium-67 scintigraphy is a commonly performed imaging modality in deteting pyrogenic lesions in cases of long-standing inexplainable fever. To re-evaluate the significance of gallium imaging in such cases, a retrospective review was made of 56 scans performed in febrile patients in whom sufficient clinical and laboratory findings were obtained. Gallium scans were true positive in 30 patients, false positive in 3, true negative in 19, and false negative in 4. In the group of true positive, local inflammatory lesions were detected in 23 patients with a final diagnosis of lung tuberculosis, urinary tract infection, and inflammatory joint disease. Abnormal gallium accumulation, as shown in the other 7 patients, provided clues to the diagnosis of generalized disorders, such as hematological malignancies (n=3), systemic autoimmune diseases (n=3), and severe infectious mononucleosis (n=one). In the group of false positive, gallium imaging revealed intestinal excretion of gallium in 2 patients and physiological pulmonary hilar accumulation in one. In the true negative group of 19 patients, fever of unknown origin was resolved spontaneously in 12 patients, and with antibiotics and corticosteroids in 2 and 5 patients, respectively. Four patients having false negative scans were finally diagnosed as having urinary tract infection (n=2), bacterial meningitis (n=one), and polyarteritis (n=one). Gallium imaging would remain the technique of choice in searching for origin of unknown fever. It may also be useful for early diagnosis of systemic disease, as well as focal inflammation. (N.K.)

  7. Egg origin determination efforts

    International Nuclear Information System (INIS)

    Horvath, A.; Futo, I.; Vodila, G.; Palcsu, L.

    2012-01-01

    Complete text of publication follows. As a co-operation with the Poultry Product Board, egg and drinking water samples were received in order to investigate whether the country of origin of the egg can be determined based on its stable isotope composition with the aim of market protection of the Hungarian eggs against the mislabelled foreign ones. The scientific background is that drinking water of egg laying hens is assumed to reflect the composition of regional precipitation, and it is also an input data in the process of egg formation. In the first sampling, altogether 23 sets of egg and drinking water samples were received from different production sites covering the whole area of Hungary. The egg white samples were vacuum distilled and frozen out by liquid nitrogen at -196 deg C. The process was monitored by two vacuum gauges. Water frozen out together with the drinking water samples was measured were measured by a Thermo Finnigan Delta PLUS XP isotope ratio mass spectrometer using a GasBench II peripheral unit equipped with a GC-autosampler. As a second issue, additionally, elemental composition of egg shells were also performed for series of Hungarian, Czech and Polish egg samples by energy dispersive X-ray fluorescence. The drinking waters fit well to the Global Meteoric Water Line indicating their precipitation origin. It was experienced that the water in egg white gets enriched compared to the drinking water (Δ 18 O = -4.9 ± 1.0 per thousand and Δ D = -21.8 ± 6.4 per thousand), however, this shift is independent of the type of the hens, since the mean shifts in the eggs of Tetra and Hy-line hens are similar within error bar. For more depleted drinking water, the shift of the egg white was higher than for more enriched ones. This can be due to the contribution of the nutriment isotopic composition. The water isotope composition of the Hungarian eggs investigated was δ 18 O = -4.8 - -7.3 per thousand and δD = -46.0 - -70.7 per thousand, therefore egg

  8. Origins of Mindfulness & Meditation

    DEFF Research Database (Denmark)

    Singla, Rashmi

    2011-01-01

    Mindfulness & meditation are gaining popularity in the Western psychological practice in the past 3-4 decades, especially within psychotherapeutic approaches, health promotion, and stress reduction. The origins and the broader context, however, seem to be overlooked in some of these practices......- mind, centrality of consciousness and meditation as a part of daily conduct are presented. The basic constructs of Buddhism, an integral part of Indian psychology, in relation to mindfulness and meditation, are also delineated as illustrations of these assumptions. The second part reflects...... on the application of the meditative practices through cognitive existential study of mindfulness (Kabat-Zinn, 2003) and a study on the phenomenology of meditation (Madsen, 2007). Both emphasise an experienced instructor, regular practice as a part of daily life, conceptual consciousness understandings...

  9. Origins of adaptive immunity.

    Science.gov (United States)

    Liongue, Clifford; John, Liza B; Ward, Alister

    2011-01-01

    Adaptive immunity, involving distinctive antibody- and cell-mediated responses to specific antigens based on "memory" of previous exposure, is a hallmark of higher vertebrates. It has been argued that adaptive immunity arose rapidly, as articulated in the "big bang theory" surrounding its origins, which stresses the importance of coincident whole-genome duplications. Through a close examination of the key molecules and molecular processes underpinning adaptive immunity, this review suggests a less-extreme model, in which adaptive immunity emerged as part of longer evolutionary journey. Clearly, whole-genome duplications provided additional raw genetic materials that were vital to the emergence of adaptive immunity, but a variety of other genetic events were also required to generate some of the key molecules, whereas others were preexisting and simply co-opted into adaptive immunity.

  10. Origins of mass

    Science.gov (United States)

    Wilczek, Frank

    2012-10-01

    Newtonian mechanics posited mass as a primary quality of matter, incapable of further elucidation. We now see Newtonian mass as an emergent property. That mass-concept is tremendously useful in the approximate description of baryon-dominated matter at low energy — that is, the standard "matter" of everyday life, and of most of science and engineering — but it originates in a highly contingent and non-trivial way from more basic concepts. Most of the mass of standard matter, by far, arises dynamically, from back-reaction of the color gluon fields of quantum chromodynamics (QCD). Additional quantitatively small, though physically crucial, contributions come from the intrinsic masses of elementary quanta (electrons and quarks). The equations for massless particles support extra symmetries — specifically scale, chiral, and gauge symmetries. The consistency of the standard model relies on a high degree of underlying gauge and chiral symmetry, so the observed non-zero masses of many elementary particles ( W and Z bosons, quarks, and leptons) requires spontaneous symmetry breaking. Superconductivity is a prototype for spontaneous symmetry breaking and for mass-generation, since photons acquire mass inside superconductors. A conceptually similar but more intricate form of all-pervasive ( i.e. cosmic) superconductivity, in the context of the electroweak standard model, gives us a successful, economical account of W and Z boson masses. It also allows a phenomenologically successful, though profligate, accommodation of quark and lepton masses. The new cosmic superconductivity, when implemented in a straightforward, minimal way, suggests the existence of a remarkable new particle, the so-called Higgs particle. The mass of the Higgs particle itself is not explained in the theory, but appears as a free parameter. Earlier results suggested, and recent observations at the Large Hadron Collider (LHC) may indicate, the actual existence of the Higgs particle, with mass m H

  11. Origins of GEMS Grains

    Science.gov (United States)

    Messenger, S.; Walker, R. M.

    2012-01-01

    Interplanetary dust particles (IDPs) collected in the Earth s stratosphere contain high abundances of submicrometer amorphous silicates known as GEMS grains. From their birth as condensates in the outflows of oxygen-rich evolved stars, processing in interstellar space, and incorporation into disks around new stars, amorphous silicates predominate in most astrophysical environments. Amorphous silicates were a major building block of our Solar System and are prominent in infrared spectra of comets. Anhydrous interplanetary dust particles (IDPs) thought to derive from comets contain abundant amorphous silicates known as GEMS (glass with embedded metal and sulfides) grains. GEMS grains have been proposed to be isotopically and chemically homogenized interstellar amorphous silicate dust. We evaluated this hypothesis through coordinated chemical and isotopic analyses of GEMS grains in a suite of IDPs to constrain their origins. GEMS grains show order of magnitude variations in Mg, Fe, Ca, and S abundances. GEMS grains do not match the average element abundances inferred for ISM dust containing on average, too little Mg, Fe, and Ca, and too much S. GEMS grains have complementary compositions to the crystalline components in IDPs suggesting that they formed from the same reservoir. We did not observe any unequivocal microstructural or chemical evidence that GEMS grains experienced prolonged exposure to radiation. We identified four GEMS grains having O isotopic compositions that point to origins in red giant branch or asymptotic giant branch stars and supernovae. Based on their O isotopic compositions, we estimate that 1-6% of GEMS grains are surviving circumstellar grains. The remaining 94-99% of GEMS grains have O isotopic compositions that are indistinguishable from terrestrial materials and carbonaceous chondrites. These isotopically solar GEMS grains either formed in the Solar System or were completely homogenized in the interstellar medium (ISM). However, the

  12. Factor of originality in advertising

    OpenAIRE

    Ešner, Rudolf

    2009-01-01

    The bachelor thesis deals with exploitation of original attitudes in advertising. The thesis solves answers, what role plays the factor of originality in advertising, when and why firms use that factor, how creators work with it, how consumers perceive the factor and what other elements it generally contains. The bachelor thesis qualifies relationship of advertising and originality, describes and probes practical situations, when originality in advertising can be used as a serious competitive...

  13. Looking at our origins

    CERN Document Server

    Nairucu Arts

    2011-01-01

    Exhibition by Nairucu-Arts, in collaboration with the Anthropology Museum Giuseppe Sergi, Università la Sapienza, Roma, Italy and ECOLINT, Campus des Nations. The exhibition comprises: posters (in English and French) intended for a large audience with text from Prof. Giorgio Manzi, Julia Rizzo, Fabio Di Vincenzo, illustrated with art drawings from Carlo Ranzi, Italy. The exhibition will also present drawings from the students of the Art Classes of Karin Bain and Fabien Bruttin at ECOLINT,Geneva. On 2nd March at 5 p.m. you will be welcomed with a drink before the conference that will be given in English at 6 p.m in the CERN Council Room by Wim De Geest, a retired Professor from KUB (Catholic University of Brussels). Title: There's no language like our language, like no language we know. But how did it evolve? A summary in French will be made available for the public. http://association.web.cern.ch/association/en/OtherActivities/Origins.html

  14. Origins of magnetospheric physics

    International Nuclear Information System (INIS)

    Van Allen, J.A.

    1983-01-01

    The history of the scientific investigation of the earth magnetosphere during the period 1946-1960 is reviewed, with a focus on satellite missions leading to the discovery of the inner and outer radiation belts. Chapters are devoted to ground-based studies of the earth magnetic field through the 1930s, the first U.S. rocket flights carrying scientific instruments, the rockoon flights from the polar regions (1952-1957), U.S. planning for scientific use of artificial satellites (1956), the launch of Sputnik I (1957), the discovery of the inner belt by Explorers I and III (1958), the Argus high-altitude atomic-explosion tests (1958), the confirmation of the inner belt and discovery of the outer belt by Explorer IV and Pioneers I-V, related studies by Sputniks II and III and Luniks I-III, and the observational and theoretical advances of 1959-1961. Photographs, drawings, diagrams, graphs, and copies of original notes and research proposals are provided. 227 references

  15. Moon (Form-Origin)

    Science.gov (United States)

    Tsiapas, Elias; Soumelidou, Despina; Tsiapas, Christos

    2017-04-01

    When the Earth was formed, it was in a state of burning heat. As time went by, temperature on the planet's surface was falling due to radiation and heat transfer, and various components (crusts) began taking solid form at the Earth's poles. The formation of crusts took place at the Earth's poles, because the stirring of burning and fluid masses on the surface of the Earth was significantly slighter there than it was on the equator. Due to centrifugal force and Coriolis Effect, these solid masses headed towards the equator; those originating from the North Pole followed a south-western course, while those originating from the South Pole followed a north-western course and there they rotated from west to east at a lower speed than the underlying burning and liquid earth, because of their lower initial linear velocity, their solid state and inertia. Because inertia is proportional to mass, the initially larger solid body swept all new solid ones, incorporating them to its western side. The density of the new solid masses was higher, because the components on the surface would freeze and solidify first, before the underlying thicker components. As a result, the western side of the initial islet of solid rocks submerged, while the east side elevated. . As a result of the above, this initial islet began to spin in reverse, and after taking on the shape of a sphere, it formed the "heart" of the Moon. The Moon-sphere, rolling on the equator, would sink the solid rocks that continued to descend from the Earth's poles. The sinking rocks partially melted because of higher temperatures in the greater depths that the Moon descended to, while part of the rocks' mass bonded with the Moon and also served as a heat-insulating material, preventing the descended side of the sphere from melting. Combined with the Earth's liquid mass that covered its emerging eastern surface, new sphere-shaped shells were created, with increased density and very powerful structural cohesion. During the

  16. Origin of fatty acids

    International Nuclear Information System (INIS)

    Prieur, B.E.

    1995-01-01

    The appearance of fatty acids and membranes is one of the most important events of the prebiotic world because genesis of life required the compartmentalization of molecules. Membranes allowed cells to become enriched with molecules relevant for their evolution and gave rise to gradients convertible into energy. By virtue of their hydrophobic/hydrophilic interface, membranes developed certain enzymatic activities impossible in the aqueous phase. A prebiotic cell is an energy unit but it is also an information unit. It has a past, a present and a future. The biochemistry of fatty acids involves acetylCoA, malonylCoA and an enzyme, acyl synthetase, which joins both molecules. After substitution of the acetyl group in place of the carboxyl group of malonyl derivatives, the chain is reduced and dehydrated to crotonyl derivatives. These molecules can again react with malonylCoA to form unsaturated chain; they can also undergo a new reduction step to form butyryl derivatives which can react with malonylCoA to form a longer aliphatic chain. The formation of malonylCoA consumes ATP. The reduction step needs NADPH and proton. Dehydration requires structural information because the reduction product is chiral (D configuration). It is unlikely that these steps were possible in a prebiotic environment. Thus we have to understand how fatty acids could appear in the prebiotic era. This hypothesis about the origin of fatty acids is based on the chemistry of sulfonium ylides and sulfonium salts. The most well-known among these molecules are S-melthyl-methionine and S-adenosyl methionine. The simplest sulfonium cation is the trimethylsulfonium cation. Chemists have evidence that these products can produce olefin when they are heated or flashed with UV light in some conditions. I suggest that these volatile products can allow the formation of fatty acids chains in atmospheric phase with UV and temperature using methanol as starting material. Different synthetic pathways will be

  17. Origin of Hawking radiation

    International Nuclear Information System (INIS)

    Hajicek, P.

    1987-01-01

    In the first part of the paper, the possible influence that quantum corrections could have on the existence and position of an event horizon in a spherically symmetric collapse is studied. A counterexample is constructed proving that the small value of near the gravitational radius does not guarantee the formation of an event horizon. In an exactly solvable model of black-hole evaporation, the spacetime structure is manipulated in the Planck neighborhood of the singularity so that the event horizon is shifted arbitrarily to the future or removed completely. This change in the position of the event horizon has no observable consequences until the retarded time of the end of the black-hole evaporation is reached. However, even in the absence of the event horizon, the Hawking radiation survives. In the second part of the paper, its origin is studied. The old idea is adopted that it is coming from a neighborhood of the so-called ergosphere. The concept of the ergosphere is generalized to nonstationary, spherically symmetric spacetimes using the notion of Hawking quasilocal mass. The boundary of such an ergosphere is shown to coincide with the locus of apparent horizons. It seems, therefore, that the Hawking effect is associated with the apparent rather than the event horizon. An extrapolation of some properties of from a neighborhood of the Schwarzschild horizon to that of an apparent horizon forming in a collapse leads to the result that too much energy is radiated away already before the apparent horizon forms, similarly as in the Boulware scenario of gravitational collapse

  18. Paraganglioma of Prostatic Origin

    Directory of Open Access Journals (Sweden)

    B. Padilla-Fernández

    2012-01-01

    Full Text Available Introduction Paragangliomas are usually benign tumors arising from chromaffin cells located outside the adrenal gland. Prostatic paraganglioma is an unusual entity in adult patients, with only 10 cases reported in the medical literature. Case Report A 34-year-old male with a history of chronic prostatitis consulted for perineal pain. On digital rectal examination the prostate was enlarged and firm, without nodules. The PSA level was 0.8 ng/mL and the catecholamines in the urine were elevated. On ultrasound a retrovesical 9 cm mass of undetermined origin measuring was present. A PET-CT scan showed a pelvic lesion measuring 9 cm with moderate increase in glucidic metabolism localized in the area of the prostate. A biopsy of the prostate revealed a neuroendocrine tumor, possibly a prostatic paraganglioma. A body scintigraphy with MIBG I-123 ruled out the presence of metastases or multifocal tumor. A radical prostatectomy with excision of the pelvic mass was performed under adrenergic blockade. One year after surgery the patient is asymptomatic and disease free. Discussion/Conclusions Prostatic paraganglioma is a rare, usually benign tumor, which should be considered in the differential diagnosis of prostate tumors in young males. Its diagnosis is based on the determination of catecholamine in blood and 24-hour urine and in imaging studies principally scintigraphy with MIBG I-123. Diagnostic confirmation is by histopathological study. The treatment consists of radical resection under adrenergic blockade and volume expansion. Given the limited number of cases reported, it is difficult to establish prognostic factors. Malignancy is defined by clinical criteria, and requires life long follow-up.

  19. Origins of narcissism in children

    NARCIS (Netherlands)

    Brummelman, E.; Thomaes, S.; Nelemans, S.A.; Orobio de Castro, B.; Overbeek, G.; Bushman, B.J.

    2015-01-01

    Narcissism levels have been increasing among Western youth, and contribute to societal problems such as aggression and violence. The origins of narcissism, however, are not well understood. Here, we report, to our knowledge, the first prospective longitudinal evidence on the origins of narcissism in

  20. The Origins of Soviet Sociolinguistics.

    Science.gov (United States)

    Brandist, Craig

    2003-01-01

    Discusses the origins of Soviet sociolinguistics and suggests that the historical significance of the reception and reinterpretation of these ideas is considerable, leading to a reconsideration of the origins of sociolinguistics and the relationship between Marxism and the language sciences in the early years of the Soviet Union. (Author/VWL)

  1. Generating original ideas: The neural underpinning of originality.

    Science.gov (United States)

    Mayseless, Naama; Eran, Ayelet; Shamay-Tsoory, Simone G

    2015-08-01

    One of the key aspects of creativity is the ability to produce original ideas. Originality is defined in terms of the novelty and rarity of an idea and is measured by the infrequency of the idea compared to other ideas. In the current study we focused on divergent thinking (DT) - the ability to produce many alternate ideas - and assessed the neural pathways associated with originality. Considering that generation of original ideas involves both the ability to generate new associations and the ability to overcome automatic common responses, we hypothesized that originality would be associated with activations in regions related to associative thinking, including areas of the default mode network (DMN) such as medial prefrontal areas, as well as with areas involved in cognitive control and inhibition. Thirty participants were scanned while performing a DT task that required the generation of original uses for common objects. The results indicate that the ability to produce original ideas is mediated by activity in several regions that are part of the DMN including the medial prefrontal cortex (mPFC) and the posterior cingulate cortex (PCC). Furthermore, individuals who are more original exhibited enhanced activation in the ventral anterior cingulate cortex (vACC), which was also positively coupled with activity in the left occipital-temporal area. These results are in line with the dual model of creativity, according to which original ideas are a product of the interaction between a system that generates ideas and a control system that evaluates these ideas. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Origin of solar radio waves

    International Nuclear Information System (INIS)

    Olmr, J.

    1977-01-01

    Solar radiowave radiation amounts to about 10 -7 of the total solar radiation. The solar atmosphere emits radiation of different wavelengths from a fraction of nanometer to kilometer waves. The solar radiowaves are of thermal origin and except for neutral hydrogen emission and solid body radio emission their emission always results from free electrons. The radiowave radiation active components were classified in several types, such as noise storms, flashes, flares, continuum, and flashes lasting for several minutes. The respective types are discussed and their origins shown. The mechanisms are described permitting the formation of radio waves of nonthermal origin, i.e., plasma oscillations, gyromagnetic emission, synchrotron and Cherenkov radiations. (J.P.)

  3. The origins of originality: the neural bases of creative thinking and originality.

    Science.gov (United States)

    Shamay-Tsoory, S G; Adler, N; Aharon-Peretz, J; Perry, D; Mayseless, N

    2011-01-01

    Although creativity has been related to prefrontal activity, recent neurological case studies postulate that patients who have left frontal and temporal degeneration involving deterioration of language abilities may actually develop de novo artistic abilities. In this study, we propose a neural and cognitive model according to which a balance between the two hemispheres affects a major aspect of creative cognition, namely, originality. In order to examine the neural basis of originality, that is, the ability to produce statistically infrequent ideas, patients with localized lesions in the medial prefrontal cortex (mPFC), inferior frontal gyrus (IFG), and posterior parietal and temporal cortex (PC), were assessed by two tasks involving divergent thinking and originality. Results indicate that lesions in the mPFC involved the most profound impairment in originality. Furthermore, precise anatomical mapping of lesions indicated that while the extent of lesion in the right mPFC was associated with impaired originality, lesions in the left PC were associated with somewhat elevated levels of originality. A positive correlation between creativity scores and left PC lesions indicated that the larger the lesion is in this area the greater the originality. On the other hand, a negative correlation was observed between originality scores and lesions in the right mPFC. It is concluded that the right mPFC is part of a right fronto-parietal network which is responsible for producing original ideas. It is possible that more linear cognitive processing such as language, mediated by left hemisphere structures interferes with creative cognition. Therefore, lesions in the left hemisphere may be associated with elevated levels of originality. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Origines de la nomenclature astrale

    Science.gov (United States)

    Duchesne-Guillemin, J.

    Within a survey of the Indo-European, Sumero-Babylonian, Greek, Arabic, and modern origins of the names of the constellations, stars, planets, satellites, asteroids, etc., an explanation is offered of the Omega sign used in Greek horoscopes for the lunar nodes but already appearing on Babylonian reliefs. Its origin is traced back to the Sumerian constellations of the Yoke, later called the Dragon.

  5. Cosmic ray: Studying the origin

    International Nuclear Information System (INIS)

    Szabelski, J.

    1997-01-01

    Investigations of the origin of cosmic rays are presented. Different methods are discussed: studies of cosmic gamma rays of energy from 30 MeV to about 10 15 eV (since photons point to their places of origin), studies of the mass composition of cosmic rays (because it reflects source morphology), and studies of cosmic rays with energy above 1O 19 eV (for these are the highest energies observed in nature). (author)

  6. ORIGIN

    African Journals Online (AJOL)

    2012-08-06

    Aug 6, 2012 ... (ACCORD),1 Action in Diabetes and Vascular disease: preterAx and DiamicroN ... (8-10 years) type 2 diabetes and who had previous. CVD. The ACCORD ... presented at the American Diabetes Association annual meeting in ...

  7. Cosmic ray: Studying the origin

    Energy Technology Data Exchange (ETDEWEB)

    Szabelski, J. [Cosmic Ray Laboratory, Soltan Institute for Nuclear Studies, Lodz (Poland)

    1997-12-31

    Investigations of the origin of cosmic rays are presented. Different methods are discussed: studies of cosmic gamma rays of energy from 30 MeV to about 10{sup 15} eV (since photons point to their places of origin), studies of the mass composition of cosmic rays (because it reflects source morphology), and studies of cosmic rays with energy above 1O{sup 19} eV (for these are the highest energies observed in nature). (author) 101 refs, 19 figs, 7 tabs

  8. Reflective Practice: Origins and Interpretations

    Science.gov (United States)

    Reynolds, Michael

    2011-01-01

    The idea of reflection is central to the theory and practice of learning--especially learning which is grounded in past or current experience. This paper proposes a working definition of reflection and reviews its origins and recent developments. The author also provides an account of "critical reflection", including its rationale and…

  9. Origin of the asteroid belt

    International Nuclear Information System (INIS)

    Wetherill, G.W.

    1989-01-01

    Earlier work and concepts relevant to the origin of the asteroid belt are reviewed and considered in the context of the more general question of solar system origin. Several aspects of asteroidal origin by accumulation of smaller bodies have been addressed by new dynamic studies. Numerical and analytical solutions of the dynamical theory of planetesimal accumulation are characterized by a bifurcation into runaway and nonrunaway solutions. The differences in time scales resulting from runaway and nonrunaway growth can be more important than conventional time scale differences determined by heliocentric distances. This introduces new possibilities, e.g., planetary accumulation may be more rapid at the distance of Jupiter than in the asteroid belt, thus permitting Jupiter to control asteroidal growth. Although alternatives must be seriously considered, the most promising approach to asteroidal origin is one in which the initial surface density of the solar nebula varied smoothly between the terrestrial and giant-planet region. In the absence of external perturbations, it is found that runaway growth of excessively large asteroids would then occur on <1 Myr, but fairly modest external perturbations by Jupiter, Saturn or other perturbers, resulting in eccentricities ∼0.01 may quench runaways, truncate asteroidal growth at their present size, and then initiate the necessary loss of asteroidal material by mutual fragmentation

  10. Social Origin and Graduation Age

    DEFF Research Database (Denmark)

    Klausen, Trond Beldo

    2016-01-01

    This paper investigates whether social origin has an impact on graduation age among university students. A large number of social background factors are applied on a large data set of 4 successive cohorts of Danish university graduates born 1960–1975. These are cohorts for whom university...

  11. Climate Drives Polar Bear Origins

    Science.gov (United States)

    In their provocative analysis of northern bears (“Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage,” Reports, 20 April, p. 344), F. Hailer et al. use independent nuclear loci to show that polar bears originated during the middle Pleistocene, rather than during t...

  12. Origin of the Gribov ambiguity

    International Nuclear Information System (INIS)

    Takahashi, Y.; Kobayashi, M.

    1978-01-01

    It is pointed out that the Gribov ambiguity for the non-abelian transverse gauge field has the same origin as the Johnson-Sudarshan problem for the spin-3/2 field as well as the propagation problem discovered by Velo and Zwanziger. (Auth.)

  13. The Country of Origin Effect

    DEFF Research Database (Denmark)

    Hu, Lala; Baldin, Andrea

    2018-01-01

    The purpose of this paper is to analyse the country of origin (COO) effect on wine purchase in China by considering a sample from an e-commerce website. The paper contribute to the literature on hedonic pricing by applying this model to the Chinese market and including COO as product attribute....

  14. Nature and origin of comets

    International Nuclear Information System (INIS)

    Fernandez, J.A.; Jockers, K.

    1983-01-01

    The review examines basic history and morphology, motion, dynamic evolution, physical properties of neutral gaseous matter, vaporization of gases and outflow from the nucleus, chemistry of the coma gases, the comet nucleus, dust particles, solar wind-comet interactions and tail formation and the origin of comets. (U.K.)

  15. Acoustic Center or Time Origin?

    DEFF Research Database (Denmark)

    Staffeldt, Henrik

    1999-01-01

    The paper discusses the acoustic center in relation to measurements of loudspeaker polar data. Also, it presents the related concept time origin and discusses the deviation that appears between positions of the acoustic center found by wavefront based and time based measuring methods....

  16. International Trade: Rules of Origin

    National Research Council Canada - National Science Library

    Jones, Vivian C; Martin, Michael F

    2008-01-01

    ...), used to determine the country of origin of merchandise entering the U.S. market, can be very simple, noncontroversial tools of international trade as long as all of the parts of a product are manufactured and assembled primarily in one country...

  17. The Origin of the Universe

    DEFF Research Database (Denmark)

    Ramazanov, Sabir

    . For this purpose, we employ the quadratic maximum likelihood method, and apply it to the search of the statistical anisotropy in the seven-year WMAP data. We confirm the large quadrupole anisotropy detected in V and W bands, which has been argued to originate from systematic eects rather than from cosmology. We...

  18. Structure and Functional Analysis of ClbQ, an Unusual Intermediate-Releasing Thioesterase from the Colibactin Biosynthetic Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Guntaka, Naga Sandhya; Healy, Alan R.; Crawford, Jason M.; Herzon, Seth B.; Bruner, Steven D. (Yale); (Florida); (Yale-MED)

    2017-09-08

    Colibactin is a genotoxic hybrid nonribosomal peptide/polyketide secondary metabolite produced by various pathogenic and probiotic bacteria residing in the human gut. The presence of colibactin metabolites has been correlated to colorectal cancer formation in several studies. The specific function of many gene products in the colibactin gene cluster can be predicted. However, the role of ClbQ, a type II editing thioesterase, has not been established. The importance of ClbQ has been demonstrated by genetic deletions that abolish colibactin cytotoxic activity, and recent studies suggest an atypical role in releasing pathway intermediates from the assembly line. Here we report the 2.0 Å crystal structure and biochemical characterization of ClbQ. Our data reveal that ClbQ exhibits greater catalytic efficiency toward acyl-thioester substrates as compared to precolibactin intermediates and does not discriminate among carrier proteins. Cyclized pyridone-containing colibactins, which are off-pathway derivatives, are not viable substrates for ClbQ, while linear precursors are, supporting a role of ClbQ in facilitating the promiscuous off-loading of premature precolibactin metabolites and novel insights into colibactin biosynthesis.

  19. Biological Role of Paenilarvins, Iturin-Like Lipopeptide Secondary Metabolites Produced by the Honey Bee Pathogen Paenibacillus larvae.

    Science.gov (United States)

    Hertlein, Gillian; Seiffert, Marlene; Gensel, Sebastian; Garcia-Gonzalez, Eva; Ebeling, Julia; Skobalj, Ranko; Kuthning, Anja; Süssmuth, Roderich D; Genersch, Elke

    2016-01-01

    The Gram-positive bacterium Paenibacillus larvae (P. larvae) is the causative agent of a deadly honey bee brood disease called American Foulbrood (AFB). AFB is a notifiable epizootic in most countries and, hence, P. larvae is of considerable relevance for veterinarians and apiculturists alike. Over the last decade, much progress has been made in the understanding of the (patho)biology of P. larvae. Recently, several non-ribosomally produced peptides (NRP) and peptide/polyketide (NRP/PK) hybrids produced by P. larvae were identified. Among these NRPs were iturin-like lipopeptides, the paenilarvins A-C. Iturins are known to exhibit strong anti-fungal activity; for some iturins, cytotoxic activity towards mammalian erythrocytes and human cancer cell lines are described. We here present our results on the analysis of the natural function of the paenilarvins during pathogenesis of P. larvae infections. We demonstrated production of paenilarvins in infected larvae. However, we could neither demonstrate cytotoxicity of paenilarvins towards cultured insect cells nor towards larvae in feeding assays. Accordingly, exposure bioassays performed with larvae infected by wild-type P. larvae and a knockout mutant of P. larvae lacking production of paenilarvins did not substantiate a role for the paenilarvins as virulence factor. Further experiments are necessary to analyze the relevance of the paenilarvins' anti-fungal activity for P. larvae infections in the presence of fungal competitors in the larval midgut or cadaver.

  20. Structure and Functional Analysis of ClbQ, an Unusual Intermediate-Releasing Thioesterase from the Colibactin Biosynthetic Pathway.

    Science.gov (United States)

    Guntaka, Naga Sandhya; Healy, Alan R; Crawford, Jason M; Herzon, Seth B; Bruner, Steven D

    2017-10-20

    Colibactin is a genotoxic hybrid nonribosomal peptide/polyketide secondary metabolite produced by various pathogenic and probiotic bacteria residing in the human gut. The presence of colibactin metabolites has been correlated to colorectal cancer formation in several studies. The specific function of many gene products in the colibactin gene cluster can be predicted. However, the role of ClbQ, a type II editing thioesterase, has not been established. The importance of ClbQ has been demonstrated by genetic deletions that abolish colibactin cytotoxic activity, and recent studies suggest an atypical role in releasing pathway intermediates from the assembly line. Here we report the 2.0 Å crystal structure and biochemical characterization of ClbQ. Our data reveal that ClbQ exhibits greater catalytic efficiency toward acyl-thioester substrates as compared to precolibactin intermediates and does not discriminate among carrier proteins. Cyclized pyridone-containing colibactins, which are off-pathway derivatives, are not viable substrates for ClbQ, while linear precursors are, supporting a role of ClbQ in facilitating the promiscuous off-loading of premature precolibactin metabolites and novel insights into colibactin biosynthesis.

  1. Historical Development of Origins Research

    Science.gov (United States)

    Lazcano, Antonio

    2010-01-01

    Following the publication of the Origin of Species in 1859, many naturalists adopted the idea that living organisms were the historical outcome of gradual transformation of lifeless matter. These views soon merged with the developments of biochemistry and cell biology and led to proposals in which the origin of protoplasm was equated with the origin of life. The heterotrophic origin of life proposed by Oparin and Haldane in the 1920s was part of this tradition, which Oparin enriched by transforming the discussion of the emergence of the first cells into a workable multidisciplinary research program. On the other hand, the scientific trend toward understanding biological phenomena at the molecular level led authors like Troland, Muller, and others to propose that single molecules or viruses represented primordial living systems. The contrast between these opposing views on the origin of life represents not only contrasting views of the nature of life itself, but also major ideological discussions that reached a surprising intensity in the years following Stanley Miller’s seminal result which showed the ease with which organic compounds of biochemical significance could be synthesized under putative primitive conditions. In fact, during the years following the Miller experiment, attempts to understand the origin of life were strongly influenced by research on DNA replication and protein biosynthesis, and, in socio-political terms, by the atmosphere created by Cold War tensions. The catalytic versatility of RNA molecules clearly merits a critical reappraisal of Muller’s viewpoint. However, the discovery of ribozymes does not imply that autocatalytic nucleic acid molecules ready to be used as primordial genes were floating in the primitive oceans, or that the RNA world emerged completely assembled from simple precursors present in the prebiotic soup. The evidence supporting the presence of a wide range of organic molecules on the primitive Earth, including membrane

  2. The origin of risk aversion.

    Science.gov (United States)

    Zhang, Ruixun; Brennan, Thomas J; Lo, Andrew W

    2014-12-16

    Risk aversion is one of the most basic assumptions of economic behavior, but few studies have addressed the question of where risk preferences come from and why they differ from one individual to the next. Here, we propose an evolutionary explanation for the origin of risk aversion. In the context of a simple binary-choice model, we show that risk aversion emerges by natural selection if reproductive risk is systematic (i.e., correlated across individuals in a given generation). In contrast, risk neutrality emerges if reproductive risk is idiosyncratic (i.e., uncorrelated across each given generation). More generally, our framework implies that the degree of risk aversion is determined by the stochastic nature of reproductive rates, and we show that different statistical properties lead to different utility functions. The simplicity and generality of our model suggest that these implications are primitive and cut across species, physiology, and genetic origins.

  3. Origins of eponymous orthopaedic equipment.

    Science.gov (United States)

    Meals, Clifton; Wang, Jeffrey

    2010-06-01

    Orthopaedists make great use of eponymous equipment, however the origins of these tools are unknown to many users. This history enriches, enlightens, and enhances surgical education, and may inspire modern innovation. We explored the origins of common and eponymous orthopaedic equipment. We selected pieces of equipment named for their inventors and in the broadest use by modern orthopaedists. We do not describe specialized orthopaedic implants and instruments owing to the overwhelming number of these devices. The history of this equipment reflects the coevolution of orthopaedics and battlefield medicine. Additionally, these stories evidence the primacy of elegant design and suggest that innovation is often a process of revision and refinement rather than sudden inspiration. Their history exposes surgical innovators as brilliant, lucky, hardworking, and sometimes odd. These stories amuse, enlighten, and may inspire modern orthopaedists to develop creative solutions of their own. The rich history of the field's eponymous instruments informs an ongoing tradition of innovation in orthopaedics.

  4. Cosmological origin of mass scales

    International Nuclear Information System (INIS)

    Terazawa, H.

    1981-01-01

    We discuss the possibility that spontaneous breakdown of conformal invariance due to the very existence of our universe originates all the mass (or length) scales ranging from the Planck mass (approx. 10 19 GeV) to the Hubble constant (approx. 10 -42 GeV) and suggest that the photon may have a curvature-dependent mass which is as small as 10 -42 GeV. We also present a possible clue to Dirac's large number hypothesis. (orig.)

  5. Cosmological origin of mass scales

    International Nuclear Information System (INIS)

    Terazawa, Hidezumi.

    1981-02-01

    We discuss the possibility that spontaneous breakdown of conformal invariance due to the very existence of our universe originates all the mass (or length) scales ranging from the Planck mass (--10 19 GeV) to the Hubble constant (--10 -42 GeV) and suggest that the photon may have a curvature-dependent mass which is as small as 10 -42 GeV. We also present a possible clue to the Dirac's large number hypothesis. (author)

  6. On origin of stellar clusters

    International Nuclear Information System (INIS)

    Tovmasyan, G.M.

    1977-01-01

    The ratios of the gas component of the mass of young stellar clusters to their stellar mass are considered. They change by more than four orders from one cluster to another. The results are in direct contradiction with the hypothesis of formation of cluster stars from a preliminarily existing gas cloud by its condensation, and they favour the Ambartsumian hypothesis of the joint origin of stars and gas clouds from superdense protostellar matter

  7. Biological origins of color categorization

    OpenAIRE

    Skelton, Alice E.; Catchpole, Gemma; Abbott, Joshua T.; Bosten, Jenny M.; Franklin, Anna

    2017-01-01

    The biological basis of the commonality in color lexicons across languages has been hotly debated for decades. Prior evidence that infants categorize color could provide support for the hypothesis that color categorization systems are not purely constructed by communication and culture. Here, we investigate the relationship between infants’ categorization of color and the commonality across color lexicons, and the potential biological origin of infant color categories. We systematically mappe...

  8. Product Origin and Food Marketing

    OpenAIRE

    Delagneau, Bernard

    1987-01-01

    The consumer's knowledge and perception of a product's country of ongm play an important role m food marketing strategies. "Think-national" campaigns are used widelym some EC countries but are not, however, as effective as quantitative restnctions on imports. Surveys and leg1slat10n at both national and EC levels reflect the desire of European consumers for "origin markmg" to appear on food product labels. National stereotypes are frequently adopted by generic and brand advertisers to promote...

  9. On the origin of inertia

    International Nuclear Information System (INIS)

    Culetu, H.

    1990-09-01

    A dynamical origin to the Minkowski geometry is suggested in this paper. The Minkowski internal (-x α x α ) 1/2 plays the role of the fifth dimension. We found the energy-momentum vector p μ (associated to a ''motion in scale'') of a ''free'' relativistic particle in position-dependent. When x i and ''t'' are not independent, we are naturally led to the law of inertia. (author). 10 refs

  10. Origins of Inner Solar Systems

    Science.gov (United States)

    Dawson, Rebekah Ilene

    2017-06-01

    Over the past couple decades, thousands of extra-solar planetshave been discovered orbiting other stars. The exoplanets discovered to date exhibit a wide variety of orbital and compositional properties; most are dramatically different from the planets in our own Solar System. Our classical theories for the origins of planetary systems were crafted to account for the Solar System and fail to account for the diversity of planets now known. We are working to establish a new blueprint for the origin of planetary systems and identify the key parameters of planet formation and evolution that establish the distribution of planetary properties observed today. The new blueprint must account for the properties of planets in inner solar systems, regions of planetary systems closer to their star than Earth’s separation from the Sun and home to most exoplanets detected to data. I present work combining simulations and theory with data analysis and statistics of observed planets to test theories of the origins of inner solars, including hot Jupiters, warm Jupiters, and tightly-packed systems of super-Earths. Ultimately a comprehensive blueprint for planetary systems will allow us to better situate discovered planets in the context of their system’s formation and evolution, important factors in whether the planets may harbor life.

  11. Origin of the solar system

    International Nuclear Information System (INIS)

    Hayashi, Chushiro; Nakazawa, Kiyoshi; Miyama, S.M.

    1989-01-01

    The study on the origin of the solar system entered a stage of synthetic and positivistic science around 1960, as the observation and the theory of protostars began to develop, the solar chemical composition became almost definite, and the amounts of chemical and mineralogical data greatly increased. In accordance with this scientific situation, the first research meeting in Japan on the origin of the solar system was held in 1965 at the Research Institute for Fundamental Physics, Kyoto University. It was discussed how a variety of the data on the solar system can be explained in a unified way. Since 1977, the workshop on the origin has been held annually. Through a series of the workshops, so-called Kyoto model has been talked and discussed frequently. For three years from 1985, the workshop in Kyoto was supported by the Ministry of Education, Science and Culture, and one of the main items of this grant was to publish the results of the workshop as the Supplement of the Progress of Theoretical Physics. The chronology of the solar system, the formation processes of protostars, the stability of solar nebulae, the physical processes in solar nebulae, the physical processes related to planetary growth, the growth of planets, and the formation of asteroids and meteorites are described in this book. (K.I.)

  12. Origins Space Telescope: Study Plan

    Science.gov (United States)

    Nayyeri, Hooshang; Cooray, Asantha; Origins Space Telescope Study Team

    2018-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its spectrographs will enable 3D surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu. This presentation will provide a summary of the OST STDT, the OST Study Team based at NASA Goddard Space Flight Center, study partners, and the advisory panel to the study. This presentation will also summarize recent activities, including the process used to reach a decision on the mission architecture, the identification of key science drivers, and the key study milestones between 2017 and 2020.

  13. The origins of medical physics.

    Science.gov (United States)

    Duck, Francis A

    2014-06-01

    The historical origins of medical physics are traced from the first use of weighing as a means of monitoring health by Sanctorius in the early seventeenth century to the emergence of radiology, phototherapy and electrotherapy at the end of the nineteenth century. The origins of biomechanics, due to Borelli, and of medical electricity following Musschenbroek's report of the Leyden Jar, are included. Medical physics emerged as a separate academic discipline in France at the time of the Revolution, with Jean Hallé as its first professor. Physiological physics flowered in Germany during the mid-nineteenth century, led by the work of Adolf Fick. The introduction of the term medical physics into English by Neil Arnott failed to accelerate its acceptance in Britain or the USA. Contributions from Newton, Euler, Bernoulli, Nollet, Matteucci, Pelletan, Gavarret, d'Arsonval, Finsen, Röntgen and others are noted. There are many origins of medical physics, stemming from the many intersections between physics and medicine. Overall, the early nineteenth-century definition of medical physics still holds today: 'Physics applied to the knowledge of the human body, to its preservation and to the cure of its illnesses'. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  14. The Origins of the Etruscans

    Directory of Open Access Journals (Sweden)

    Paolo Agostini

    2000-06-01

    Full Text Available During the Humanist period there was a development of the historical studies as well as epigraphic and archaeological investigations. It was then that the first hypotheses about the origins of the Etruscans appeared. Yet, the more or less scientific approaches to the question of the origins made their appearance in the eighteenth century and they took three different directions. The one theory assumes an oriental origin, the second one a northern origin and the third one presupposes that the Etruscans are an autochthonous people. The first theory is based on the tradition handed down to us by Herodotus, who narrates the migration of a group of Lydians under the guidance of Tyrrhenos, son of king Atys, and this one would be the reason why the Greeks called the Etruscans “Tyrrhenians”. Although having been rejected by modern criticism, this idea found some support in the discovery of epigraphic material in the Isle of Lemnos, in front of the Lydian seaside. The writing and some linguistic elements of the Lemnian epigraphs are very similar to the language spoken by the Etruscans. Other historians, setting out from the great number of objects of oriental origin and, generally speaking, on the culture of the VII and VI century BC which was strongly influenced by eastern elements, spoke emphatically in favour of an oriental origin. According to the latter historians, such an abundance of eastern cultural elements could only be explained by a mass immigration in Etruria of a people coming from the East. Another theory, based on the archaeological studies of the paleo-ethnologist Luigi Pigorini, hypothesizes a southward migration of Etruscan and Italic peoples coming from the north. These peoples are assumed to have introduced in Italy the ritual of incineration or cremation, which partly ousted inhumation. This theory, which did not enjoy much favour, assumes that the Etruscan element is connected with the Villanovan. The third theory, going back

  15. 17 CFR 200.505 - Original classification.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Original classification. 200... Information and Material § 200.505 Original classification. (a) No Commission Member or employee has the authority to classify any information on an original basis. (b) If a Commission employee originates...

  16. 32 CFR 2001.21 - Original classification.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Original classification. 2001.21 Section 2001.21... Markings § 2001.21 Original classification. (a) Primary markings. At the time of original classification... authority. The name and position, or personal identifier, of the original classification authority shall...

  17. Musical emotions: Functions, origins, evolution

    Science.gov (United States)

    Perlovsky, Leonid

    2010-03-01

    Theories of music origins and the role of musical emotions in the mind are reviewed. Most existing theories contradict each other, and cannot explain mechanisms or roles of musical emotions in workings of the mind, nor evolutionary reasons for music origins. Music seems to be an enigma. Nevertheless, a synthesis of cognitive science and mathematical models of the mind has been proposed describing a fundamental role of music in the functioning and evolution of the mind, consciousness, and cultures. The review considers ancient theories of music as well as contemporary theories advanced by leading authors in this field. It addresses one hypothesis that promises to unify the field and proposes a theory of musical origin based on a fundamental role of music in cognition and evolution of consciousness and culture. We consider a split in the vocalizations of proto-humans into two types: one less emotional and more concretely-semantic, evolving into language, and the other preserving emotional connections along with semantic ambiguity, evolving into music. The proposed hypothesis departs from other theories in considering specific mechanisms of the mind-brain, which required the evolution of music parallel with the evolution of cultures and languages. Arguments are reviewed that the evolution of language toward becoming the semantically powerful tool of today required emancipation from emotional encumbrances. The opposite, no less powerful mechanisms required a compensatory evolution of music toward more differentiated and refined emotionality. The need for refined music in the process of cultural evolution is grounded in fundamental mechanisms of the mind. This is why today's human mind and cultures cannot exist without today's music. The reviewed hypothesis gives a basis for future analysis of why different evolutionary paths of languages were paralleled by different evolutionary paths of music. Approaches toward experimental verification of this hypothesis in

  18. Becquerel and natural origin radioactivity

    International Nuclear Information System (INIS)

    2011-01-01

    After a brief presentation of the Becquerel as radioactivity measurement unit, this document briefly explains the origin of natural radioactivity (Earth formation and cosmic rays), gives and comments the evolution of radioactivity of some radionuclides (U 238 and descendants, Th 232 and descendants, K 40 ) between 4.5 billions yeas ago and nowadays. It also gives assessments of natural radioactivity due to radon in the atmosphere and in the soil, of natural radioactivity in building materials, coals, ashes, seawater and food. Some remarkable figures are then given

  19. Origins of the "Western" Constellations

    Science.gov (United States)

    Frank, Roslyn M.

    The development of the 48 Greek constellations is analyzed as a complex mixture of cognitive layers deriving from different cultural traditions and dating back to different epochs. The analysis begins with a discussion of the zodiacal constellations, goes on to discuss the stellar lore in Homer and Hesiod, and then examines several theories concerning the origins of the southern non-zodiacal constellations. It concludes with a commentary concerning the age and possible cultural significance of stars of the Great Bear constellation in light of ethnohistorical documentation, folklore, and beliefs related to European bear ceremonialism.

  20. Origin of Scottish oil shales

    Energy Technology Data Exchange (ETDEWEB)

    Conacher, H R.J.

    1916-12-01

    Oil shales contain two distinct types of organic material, one is comparable to the woody material in coal and the other consists of yellow bodies. When distilled, the latter yields the liquid product typical of oil shale, whereas the woody material produces large amounts of ammonia. The yellow bodies have been described by various investigators as fossil algae, spores, or dried-up globules of petroleum. In this study it was concluded that the yellow bodies were fragments of resins set free by the decay and oxidation of the vegetable matter with which they were originally associated.

  1. Origin of faint blue stars

    International Nuclear Information System (INIS)

    Tutukov, A.; Iungelson, L.

    1987-01-01

    The origin of field faint blue stars that are placed in the HR diagram to the left of the main sequence is discussed. These include degenerate dwarfs and O and B subdwarfs. Degenerate dwarfs belong to two main populations with helium and carbon-oxygen cores. The majority of the hot subdwarfs most possibly are helium nondegenerate stars that are produced by mass exchange close binaries of moderate mass cores (3-15 solar masses). The theoretical estimates of the numbers of faint blue stars of different types brighter than certain stellar magnitudes agree with star counts based on the Palomar Green Survey. 28 references

  2. The Natural Origins of Content

    DEFF Research Database (Denmark)

    Hutto, Daniel; Satne, Glenda Lucila

    2015-01-01

    to be reconceived in terms of explaining the natural origins of content. Second, the pivotal assumption that intentionality is always and everywhere contentful must be abandoned. Reviving and updating Haugeland’s baseball analogy in the light of these changes, we propose ways of redirecting the efforts of players...... on each base of his intentionality All-Star team, enabling them to start functioning effectively as a team. Only then is it likely that they will finally get their innings and maybe, just maybe, even win the game....

  3. Origin of the chemical elements

    Energy Technology Data Exchange (ETDEWEB)

    Tayler, R J

    1984-05-01

    The subject is discussed in relation to the composition of initially created matter and changes which have occurred during the life history of the universe, with particular reference to our galaxy and nearby galaxies. Headings are: observations of element abundances (stars, gas clouds in our own and nearby galaxies, hot gas in galaxy clusters, the solar system); the originally created matter (Big Bang theory and early nuclear reactions); processes changing observed composition (galactic evolution; nuclear fusion reactions in stellar interiors; chemical composition of a highly evolved massive star); supernovae (production of heavy elements); chemical evolution of the galaxy; production of very heavy elements (s process, r process).

  4. Electronic Computer Originated Mail Service

    Science.gov (United States)

    Seto, Takao

    Electronic mail originated by computer is exactly a new communication media which is a product of combining traditional mailing with electrical communication. Experimental service of this type of mailing started in June 10, 1985 at Ministry of Posts and Telecommunications. Its location in various communication media, its comparison with facsimile type electronic mailing, and status quo of electronic mailing in foreign countries are described. Then, this mailing is briefed centering around the system organization and the services. Additional services to be executed in near future are also mentioned.

  5. The origin of life at the origin of ageing?

    Science.gov (United States)

    Currais, Antonio

    2017-05-01

    At first glance, the ageing of unicellular organisms would appear to be different from the ageing of complex, multicellular organisms. In an attempt to describe the nature of ageing in diverse organisms, the intimate links between the origins of life and ageing are examined. Departing from Leslie Orgel's initial ideas on why organisms age, it is then discussed how the potentially detrimental events characteristic of ageing are continuous, cell-autonomous and universal to all organisms. The manifestation of these alterations relies on the balance between their production and cellular renewal. Renewal is achieved not only by repair and maintenance mechanisms but, importantly, by the process of cell division such that every time cells divide ageing-associated effects are diluted. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. On the Origin of Heterotrophy.

    Science.gov (United States)

    Schönheit, Peter; Buckel, Wolfgang; Martin, William F

    2016-01-01

    The theory of autotrophic origins of life posits that the first cells on Earth satisfied their carbon needs from CO2. At hydrothermal vents, spontaneous synthesis of methane via serpentinization links an energy metabolic reaction with a geochemical homologue. If the first cells were autotrophs, how did the first heterotrophs arise, and what was their substrate? We propose that cell mass roughly similar to the composition of Escherichia coli was the substrate for the first chemoorganoheterotrophs. Amino acid fermentations, pathways typical of anaerobic clostridia and common among anaerobic archaea, in addition to clostridial type purine fermentations, might have been the first forms of heterotrophic carbon and energy metabolism. Ribose was probably the first abundant sugar, and the archaeal type III RubisCO pathway of nucleoside monophosphate conversion to 3-phosphoglycerate might be a relic of ancient heterotrophy. Participation of chemiosmotic coupling and flavin-based electron bifurcation--a soluble energy coupling process--in clostridial amino acid and purine fermentations is consistent with an autotrophic origin of both metabolism and heterotrophy, as is the involvement of S(0) as an electron acceptor in the facilitated fermentations of anaerobic heterotrophic archaea. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Origins of narcissism in children.

    Science.gov (United States)

    Brummelman, Eddie; Thomaes, Sander; Nelemans, Stefanie A; Orobio de Castro, Bram; Overbeek, Geertjan; Bushman, Brad J

    2015-03-24

    Narcissism levels have been increasing among Western youth, and contribute to societal problems such as aggression and violence. The origins of narcissism, however, are not well understood. Here, we report, to our knowledge, the first prospective longitudinal evidence on the origins of narcissism in children. We compared two perspectives: social learning theory (positing that narcissism is cultivated by parental overvaluation) and psychoanalytic theory (positing that narcissism is cultivated by lack of parental warmth). We timed the study in late childhood (ages 7-12), when individual differences in narcissism first emerge. In four 6-mo waves, 565 children and their parents reported child narcissism, child self-esteem, parental overvaluation, and parental warmth. Four-wave cross-lagged panel models were conducted. Results support social learning theory and contradict psychoanalytic theory: Narcissism was predicted by parental overvaluation, not by lack of parental warmth. Thus, children seem to acquire narcissism, in part, by internalizing parents' inflated views of them (e.g., "I am superior to others" and "I am entitled to privileges"). Attesting to the specificity of this finding, self-esteem was predicted by parental warmth, not by parental overvaluation. These findings uncover early socialization experiences that cultivate narcissism, and may inform interventions to curtail narcissistic development at an early age.

  8. Phenomenology in Its Original Sense.

    Science.gov (United States)

    van Manen, Max

    2017-05-01

    In this article, I try to think through the question, "What distinguishes phenomenology in its original sense?" My intent is to focus on the project and methodology of phenomenology in a manner that is not overly technical and that may help others to further elaborate on or question the singular features that make phenomenology into a unique qualitative form of inquiry. I pay special attention to the notion of "lived" in the phenomenological term "lived experience" to demonstrate its critical role and significance for understanding phenomenological reflection, meaning, analysis, and insights. I also attend to the kind of experiential material that is needed to focus on a genuine phenomenological question that should guide any specific research project. Heidegger, van den Berg, and Marion provide some poignant exemplars of the use of narrative "examples" in phenomenological explorations of the phenomena of "boredom," "conversation," and "the meaningful look in eye-contact." Only what is given or what gives itself in lived experience (or conscious awareness) are proper phenomenological "data" or "givens," but these givens are not to be confused with data material that can be coded, sorted, abstracted, and accordingly analyzed in some "systematic" manner. The latter approach to experiential research may be appropriate and worthwhile for various types of qualitative inquiry but not for phenomenology in its original sense. Finally, I use the mythical figure of Kairos to show that the famous phenomenological couplet of the epoché-reduction aims for phenomenological insights that require experiential analysis and attentive (but serendipitous) methodical inquiry practices.

  9. Origin of marine planktonic cyanobacteria.

    Science.gov (United States)

    Sánchez-Baracaldo, Patricia

    2015-12-01

    Marine planktonic cyanobacteria contributed to the widespread oxygenation of the oceans towards the end of the Pre-Cambrian and their evolutionary origin represents a key transition in the geochemical evolution of the Earth surface. Little is known, however, about the evolutionary events that led to the appearance of marine planktonic cyanobacteria. I present here phylogenomic (135 proteins and two ribosomal RNAs), Bayesian relaxed molecular clock (18 proteins, SSU and LSU) and Bayesian stochastic character mapping analyses from 131 cyanobacteria genomes with the aim to unravel key evolutionary steps involved in the origin of marine planktonic cyanobacteria. While filamentous cell types evolved early on at around 2,600-2,300 Mya and likely dominated microbial mats in benthic environments for most of the Proterozoic (2,500-542 Mya), marine planktonic cyanobacteria evolved towards the end of the Proterozoic and early Phanerozoic. Crown groups of modern terrestrial and/or benthic coastal cyanobacteria appeared during the late Paleoproterozoic to early Mesoproterozoic. Decrease in cell diameter and loss of filamentous forms contributed to the evolution of unicellular planktonic lineages during the middle of the Mesoproterozoic (1,600-1,000 Mya) in freshwater environments. This study shows that marine planktonic cyanobacteria evolved from benthic marine and some diverged from freshwater ancestors during the Neoproterozoic (1,000-542 Mya).

  10. Intracardiac metastasis originated from chondrosarcoma.

    Science.gov (United States)

    Maurea, Nicola; Ragone, Gianluca; Coppola, Carmela; Caronna, Antonietta; Tocchetti, Carlo G; Agozzino, Lucio; Apice, Gaetano; Iaffaioli, Rosario V

    2017-05-01

    Primary cardiac tumors are extremely rare. By comparison, metastatic involvement of the heart is over 20 times more common and has been reported in autopsy series in up to one in five patients dying of cancer. Cardiac metastasis of chondrosarcoma is absolutely not frequent. In the recent literature, a cardiac metastasis from chondrosarcoma has never been described. We report the case of an 18-year-old man with a diagnosis of cardiac metastasis that originated from a left scapular chondrosarcoma. Chondrosarcoma is a skeletal tumor with various grades of malignancy, rapidly evolving, and with a strong tendency to metastasize, with low responsiveness to chemotherapy. The onset of characteristic systemic symptoms in the late stage of the disease led to the diagnosis of a mass localized in the right atrium. Management and differential diagnosis of infective heart lesions were also very complex in a rapidly evolving life-threatening condition.

  11. The Solar System Origin Revisited

    Science.gov (United States)

    Johnson, Fred M.

    2016-10-01

    A novel theory will be presented based in part on astronomical observations, plasma physics experiments, principles of physics and forensic techniques. The new theory correctly predicts planetary distances with a 1% precision. It accounts for energy production mechanism inside all of the planets including our Earth. A log-log mass-luminosity plot of G2 class stars and solar system planets results in a straight line plot, whose slope implies that a fission rather than a proton-proton fusion energy production is operating. Furthermore, it is a confirmation that all our planets had originated from within our Sun. Other still-born planets continue to appear on the Sun's surface, they are mislabeled as sunspots.

  12. Origin and development of comets

    International Nuclear Information System (INIS)

    Kresak, L.

    1989-01-01

    The comets are the most primitive and probably also the oldest members of the solar system. Comet cores are brittle bodies of an irregular shape and of a size of 1 to 10 km whose main component is ice. Around 130 comets move along short-period paths whose aphelia are concentrated in the area of Jupiter. They are in the last stage of development. About 20 comets have periods of 20 to 200 years and feature higher motion stability. Roughly 180 comets have elliptical orbits of a period exceeding 200 years, 200 comets have parabolic and 120 comets have hyperbolic orbits. The most distant comets form the Oort cloud around the solar system consisting of about one billion comets. Comets originated roughly 4.6 thousand million years ago together with planets, probably inside the Oort cloud. (M.D.). 11 figs

  13. Chemical origins of frictional aging.

    Science.gov (United States)

    Liu, Yun; Szlufarska, Izabela

    2012-11-02

    Although the basic laws of friction are simple enough to be taught in elementary physics classes and although friction has been widely studied for centuries, in the current state of knowledge it is still not possible to predict a friction force from fundamental principles. One of the highly debated topics in this field is the origin of static friction. For most macroscopic contacts between two solids, static friction will increase logarithmically with time, a phenomenon that is referred to as aging of the interface. One known reason for the logarithmic growth of static friction is the deformation creep in plastic contacts. However, this mechanism cannot explain frictional aging observed in the absence of roughness and plasticity. Here, we discover molecular mechanisms that can lead to a logarithmic increase of friction based purely on interfacial chemistry. Predictions of our model are consistent with published experimental data on the friction of silica.

  14. L’origine, la ferita

    Directory of Open Access Journals (Sweden)

    Filippo Fimiani

    2015-11-01

    Full Text Available Shutter Island (Paramount Pictures 2010 is a much-criticized and highly debated film. Scorsese, in fact, has been accused of distorting the facts and altering his historical sources. The depictions we see of the Holocaust are false, not based on visual documents, a mix of incompatible evidences and iconographies, an amalgam of irreconcilable informations and representations. The director has created a visual style and a sound design that vacillate between thriller and horror, drama and fantasy, while betraying the medial transparency of the reconstruction and the ethical responsibility of interpretation. The viewer sees and believes in the images of the concentration camp of Dachau which are, in reality, dialectical imaginings of another scene: in these images, constructed according to the clinical and critical vision of Scorsese as cinephile, the past and the repressed return in the present. In our present too. On the one hand, in fact, the viewer participates empathically in the mental images relived and suffered by the protagonist in his post-traumatic hallucinations; on the other hand, the viewer is prompted to recall the pictures quoted or paraphrased from the archives of the imagery of cinema and of the photojournalism of war–in which Pontecorvo, Resnais, Fuller, George Stevens and John Huston live side by side with the RKO horror films of Jacques Tourneur and Mark Robson. For Scorsese, the images of the violence of war and of the horror of extermination cannot be linked to an origin or past that have definitively been concluded. They are more than recorded pictures or concrete evidences: they are clues and symptoms. They come from a conflictual and endless descent of which cinema is the living and ambiguous memory; they are the open wounds of an original struggle between human and inhuman and of man–they still survive, here and now.

  15. The Origin of the Chemical Elements, 1

    Science.gov (United States)

    Selbin, Joel

    1973-01-01

    The problem of the origin is inextricably interwoven with such matters as the origin of the universe, the structure and evolution of galaxies, stars and other astronomical objects, and with nuclear physics. (Author/DF)

  16. 19 CFR 10.594 - Originating goods.

    Science.gov (United States)

    2010-04-01

    ... States Free Trade Agreement Rules of Origin § 10.594 Originating goods. Except as otherwise provided in... good otherwise satisfies any applicable regional value content or other requirements specified in...

  17. Origin of the solar system. I

    International Nuclear Information System (INIS)

    Prentice, A.J.R.

    1978-01-01

    A theory for the origin of the solar system, which is based on ideas of supersonic turbulent convection and indicates the possibility that the original Laplacian hypothesis may by valid, is presented. (Auth.)

  18. Human origins: Out of Africa

    Science.gov (United States)

    Tattersall, Ian

    2009-01-01

    Our species, Homo sapiens, is highly autapomorphic (uniquely derived) among hominids in the structure of its skull and postcranial skeleton. It is also sharply distinguished from other organisms by its unique symbolic mode of cognition. The fossil and archaeological records combine to show fairly clearly that our physical and cognitive attributes both first appeared in Africa, but at different times. Essentially modern bony conformation was established in that continent by the 200–150 Ka range (a dating in good agreement with dates for the origin of H. sapiens derived from modern molecular diversity). The event concerned was apparently short-term because it is essentially unanticipated in the fossil record. In contrast, the first convincing stirrings of symbolic behavior are not currently detectable until (possibly well) after 100 Ka. The radical reorganization of gene expression that underwrote the distinctive physical appearance of H. sapiens was probably also responsible for the neural substrate that permits symbolic cognition. This exaptively acquired potential lay unexploited until it was “discovered” via a cultural stimulus, plausibly the invention of language. Modern humans appear to have definitively exited Africa to populate the rest of the globe only after both their physical and cognitive peculiarities had been acquired within that continent. PMID:19805256

  19. ORIGINS AND RAMIFICATIONS OF PHARMACEUTICALS ...

    Science.gov (United States)

    Perhaps more so than with any other class of pollutants, the occurrence of pharmaceuticals and personal care products (PPCPS) in the environment highlights the immediate, intimate, and inseparable connection between the personal activities of individual citizens and their environment. PPCPS, in contrast to other types of pollutants, owe their origins in the environment directly to their worldwide, universal, frequent, highly dispersed, and individually small but cumulative usage by multitudes of individuals - as opposed to the larger, highly delineated, and more controllable industrial manufacturing/usage of most high- volume synthetic chemicals. Many PPCPs (as well as their metabolites and transformation products) can enter the environment following ingestion or application by the user or administration to domestic animals. Disposal of unused/expired PPCPs in landfills and in domestic sewage is another route to the environment. The aquatic environment serves as the major, ultimate receptacle for these chemicals, for which little is known with respect to actual or potential adverse effects. Domestic sewage treatment plants are not designed to remove PPCPS, and the efficiencies with which they are removed vary from nearly complete to ineffective. While PPCPs in the environment (or domestic drinking water) are not regulated, and even though their concentrations are extremely low (ng/L-@Lg/L), the consequences of exposure to multiple compounds having different as w

  20. Origin of the solar system

    International Nuclear Information System (INIS)

    Nakazawa, Kiyoshi; Nakagawa, Yoshitsugu

    1982-01-01

    Many studies on the origin of the solar system have so far been made until now. These are divided into three categories; Cameron's model, Safronov's model and Kyoto model. In Cameron's model, as an initial stage of the formation of the solar system, a massive solar nebula is assumed whose mass is as large as one solar mass. This solar nebula is unstable against gravitational fragmentation, which leads to massive gaseous protoplanets. On the other hand, in both models of Safronov and us, the mass of the nebula is of the order of a few percent of the solar mass or less. However, a significant difference between Safronov's and ours lies in the continuing accumulation process of planetesimals; in the former, the accumulation is assumed to proceed in a gas-free space, but in the latter, the gas drag effect of the solar nebula is fully taken into account on the planetary growth. In this paper, the scenario of Kyoto model is reviewed, which has been developed by Hayashi and his co-workers in Kyoto group for these ten years. We will see that the gas of the solar nebula has played extensively important roles on the various stages of the planetary formation. (author)

  1. Origins of Deconstruction in Nietzsche

    Directory of Open Access Journals (Sweden)

    AA Mosleh

    2014-02-01

    Full Text Available Derrida’s deconstruction is formed in relation to different philosophical movements such as existentialism, phenomenology, and structuralism. In this inquiry, we will search the origin of deconstruction in texts and philosophy of Friedrisch Nietzsche. We will show that Derrida’s thought is a development of Nietzsche’s critic of metaphysical thought. Most important Derridean concepts such as metaphysics of presence, diferrance, and critic of logocentrism are basically Nietzschean. Nietzsche was very pessimistic about philosophical thought and sought a nonphilosophical and nontheoretical thought. He introduced art as a view to the world that is free from limitations of theoretical thought. In Derrida, also, we can see this pessimistic view to philosophical thought, but he insists that this view is formed inside of philosophical thought. He introduced a practical thought instead of theoretical thought and systematically criticized the latter. We will show that Derrida’s deconstruction is an attempt to make a distance from theoretical thought and, thus, is a Nietzschean movement. This is an attempt to find a way in philosophy that does not have to be theoretical an attempt begun in Nietzsche and culminated in Derrida.

  2. Origins of Deconstruction in Nietzsche

    Directory of Open Access Journals (Sweden)

    AA Mosleh

    2014-03-01

    Full Text Available Derrida’s deconstruction is formed in relation to different philosophical movements such as existentialism, phenomenology, and structuralism. In this inquiry, we will search the origin of deconstruction in texts and philosophy of Friedrisch Nietzsche. We will show that Derrida’s thought is a development of Nietzsche’s critic of metaphysical thought. Most important Derridean concepts such as metaphysics of presence, diferrance, and critic of logocentrism are basically Nietzschean. Nietzsche was very pessimistic about philosophical thought and sought a nonphilosophical and nontheoretical thought. He introduced art as a view to the world that is free from limitations of theoretical thought. In Derrida, also, we can see this pessimistic view to philosophical thought, but he insists that this view is formed inside of philosophical thought. He introduced a practical thought instead of theoretical thought and systematically criticized the latter. We will show that Derrida’s deconstruction is an attempt to make a distance from theoretical thought and, thus, is a Nietzschean movement. This is an attempt to find a way in philosophy that does not have to be theoretical an attempt begun in Nietzsche and culminated in Derrida.

  3. Biological origins of color categorization.

    Science.gov (United States)

    Skelton, Alice E; Catchpole, Gemma; Abbott, Joshua T; Bosten, Jenny M; Franklin, Anna

    2017-05-23

    The biological basis of the commonality in color lexicons across languages has been hotly debated for decades. Prior evidence that infants categorize color could provide support for the hypothesis that color categorization systems are not purely constructed by communication and culture. Here, we investigate the relationship between infants' categorization of color and the commonality across color lexicons, and the potential biological origin of infant color categories. We systematically mapped infants' categorical recognition memory for hue onto a stimulus array used previously to document the color lexicons of 110 nonindustrialized languages. Following familiarization to a given hue, infants' response to a novel hue indicated that their recognition memory parses the hue continuum into red, yellow, green, blue, and purple categories. Infants' categorical distinctions aligned with common distinctions in color lexicons and are organized around hues that are commonly central to lexical categories across languages. The boundaries between infants' categorical distinctions also aligned, relative to the adaptation point, with the cardinal axes that describe the early stages of color representation in retinogeniculate pathways, indicating that infant color categorization may be partly organized by biological mechanisms of color vision. The findings suggest that color categorization in language and thought is partially biologically constrained and have implications for broader debate on how biology, culture, and communication interact in human cognition.

  4. Phylogenetic Origins of Brain Organisers

    Directory of Open Access Journals (Sweden)

    Ellen Robertshaw

    2012-01-01

    Full Text Available The regionalisation of the nervous system begins early in embryogenesis, concomitant with the establishment of the anteroposterior (AP and dorsoventral (DV body axes. The molecular mechanisms that drive axis induction appear to be conserved throughout the animal kingdom and may be phylogenetically older than the emergence of bilateral symmetry. As a result of this process, groups of patterning genes that are equally well conserved are expressed at specific AP and DV coordinates of the embryo. In the emerging nervous system of vertebrate embryos, this initial pattern is refined by local signalling centres, secondary organisers, that regulate patterning, proliferation, and axonal pathfinding in adjacent neuroepithelium. The main secondary organisers for the AP neuraxis are the midbrain-hindbrain boundary, zona limitans intrathalamica, and anterior neural ridge and for the DV neuraxis the notochord, floor plate, and roof plate. A search for homologous secondary organisers in nonvertebrate lineages has led to controversy over their phylogenetic origins. Based on a recent study in hemichordates, it has been suggested that the AP secondary organisers evolved at the base of the deuterostome superphylum, earlier than previously thought. According to this view, the lack of signalling centres in some deuterostome lineages is likely to reflect a secondary loss due to adaptive processes. We propose that the relative evolutionary flexibility of secondary organisers has contributed to a broader morphological complexity of nervous systems in different clades.

  5. The Origin of Runaway Stars

    Science.gov (United States)

    Hoogerwerf, R.; de Bruijne, J. H. J.; de Zeeuw, P. T.

    2000-12-01

    Milliarcsecond astrometry provided by Hipparcos and by radio observations makes it possible to retrace the orbits of some of the nearest runaway stars and pulsars to determine their site of origin. The orbits of the runaways AE Aurigae and μ Columbae and of the eccentric binary ι Orionis intersected each other ~2.5 Myr ago in the nascent Trapezium cluster, confirming that these runaways were formed in a binary-binary encounter. The path of the runaway star ζ Ophiuchi intersected that of the nearby pulsar PSR J1932+1059, ~1 Myr ago, in the young stellar group Upper Scorpius. We propose that this neutron star is the remnant of a supernova that occurred in a binary system that also contained ζ Oph and deduce that the pulsar received a kick velocity of ~350 km s-1 in the explosion. These two cases provide the first specific kinematic evidence that both mechanisms proposed for the production of runaway stars, the dynamical ejection scenario and the binary-supernova scenario, operate in nature.

  6. Origin of the solar system

    International Nuclear Information System (INIS)

    Alfven, H.

    1976-01-01

    The methodology of the problem of the origin and evolution of the Solar System is analysed and it is pointed out that one can approach it in two different ways. (1) One can postulate that long ago there was a certain more or less likely-state, and then calculate how this developed into the present state. In principle this approach is 'mythological' and it differs from the old myths mainly in the respect that it is formulated in a mathematical way. (2) One can start from the present state and reconstruct increasingly older states. This is what the geologists call the 'actualist approach' and is the only one which can claim to be scientific. The 'Laplacean' type of theories is criticized. There is no indication that there was a 'Laplacean' homogeneous disc as an intermediate state, and there is no acceptable mechanism through which the present solar system could be formed from such a disc. The solar system today has a band structure, the planets as well as the satellites all fall in certain bands characterized by certain values of the gravitational potential. The band structure is explained as a result of the ionization of infalling matter when its velocity has reached the 'critical velocity' for ionization. (Auth.)

  7. Nanogranular origin of concrete creep.

    Science.gov (United States)

    Vandamme, Matthieu; Ulm, Franz-Josef

    2009-06-30

    Concrete, the solid that forms at room temperature from mixing Portland cement with water, sand, and aggregates, suffers from time-dependent deformation under load. This creep occurs at a rate that deteriorates the durability and truncates the lifespan of concrete structures. However, despite decades of research, the origin of concrete creep remains unknown. Here, we measure the in situ creep behavior of calcium-silicate-hydrates (C-S-H), the nano-meter sized particles that form the fundamental building block of Portland cement concrete. We show that C-S-H exhibits a logarithmic creep that depends only on the packing of 3 structurally distinct but compositionally similar C-S-H forms: low density, high density, ultra-high density. We demonstrate that the creep rate ( approximately 1/t) is likely due to the rearrangement of nanoscale particles around limit packing densities following the free-volume dynamics theory of granular physics. These findings could lead to a new basis for nanoengineering concrete materials and structures with minimal creep rates monitored by packing density distributions of nanoscale particles, and predicted by nanoscale creep measurements in some minute time, which are as exact as macroscopic creep tests carried out over years.

  8. Fetal Origin of Sensorimotor Behavior

    Directory of Open Access Journals (Sweden)

    Jaqueline Fagard

    2018-05-01

    Full Text Available The aim of this article is to track the fetal origin of infants’ sensorimotor behavior. We consider development as the self-organizing emergence of complex forms from spontaneously generated activity, governed by the innate capacity to detect and memorize the consequences of spontaneous activity (contingencies, and constrained by the sensory and motor maturation of the body. In support of this view, we show how observations on fetuses and also several fetal experiments suggest that the fetus’s first motor activity allows it to feel the space around it and to feel its body and the consequences of its movements on its body. This primitive motor babbling gives way progressively to sensorimotor behavior which already possesses most of the characteristics of infants’ later behavior: repetition of actions leading to sensations, intentionality, some motor control and oriented reactions to sensory stimulation. In this way the fetus can start developing a body map and acquiring knowledge of its limited physical and social environment.

  9. On the Origin of Interoception.

    Science.gov (United States)

    Ceunen, Erik; Vlaeyen, Johan W S; Van Diest, Ilse

    2016-01-01

    Over the course of a century, the meaning of interoception has changed from the restrictive to the inclusive. In its inclusive sense, it bears relevance to every individual via its link to emotion, decision making, time-perception, health, pain, and various other areas of life. While the label for the perception of the body state changes over time, the need for an overarching concept remains. Many aspects can make any particular interoceptive sensation unique and distinct from any other interoceptive sensation. This can range from the sense of agency, to the physical cause of a sensation, the ontogenetic origin, the efferent innervation, and afferent pathways of the tissue involved amongst others. In its overarching meaning, interoception primarily is a product of the central nervous system, a construct based on an integration of various sources, not per se including afferent information. This paper proposes a definition of interoception as based on subjective experience, and pleas for the use of specific vocabulary in addressing the many aspects that contribute to it.

  10. Origin of giant Martian polygons

    Science.gov (United States)

    Mcgill, George E.; Hills, L. S.

    1992-01-01

    Extensive areas of the Martian northern plains in Utopia and Acidalia planitiae are characterized by 'polygonal terrane'. Polygonal terrane consists of material cut by complex troughs defining a pattern resembling mudcracks, columnar joints, or frost-wedge polygons on earth. However, the Martian polygons are orders of magnitude larger than these potential earth analogues, leading to severe mechanical difficulties for genetic models based on simple analogy arguments. Plate-bending and finite element models indicate that shrinkage of desiccating sediment or cooling volcanics accompanied by differential compaction over buried topography can account for the stresses responsible for polygon troughs as well as the large size of the polygons. Although trough widths and depths relate primarily to shrinkage, the large scale of the polygonl pattern relates to the spacing between topographic elevations on the surface buried beneath polygonal terrane material. Geological relationships favor a sedimentary origin for polygonal terrane material, but our model is not dependent on the specific genesis. Our analysis also suggests that the polygons must have formed at a geologically rapid rate.

  11. The Origins of Human Modernity

    Directory of Open Access Journals (Sweden)

    Robert G. Bednarik

    2011-09-01

    Full Text Available This paper addresses the development of the human species during a relatively short period in its evolutionary history, the last forty millennia of the Pleistocene. The hitherto dominant hypotheses of “modern” human origins, the replacement and various other “out of Africa” models, have recently been refuted by the findings of several disciplines, and by a more comprehensive review of the archaeological evidence. The complexity of the subject is reconsidered in the light of several relevant frames of reference, such as those provided by niche construction and gene-culture co-evolutionary theories, and particularly by the domestication hypothesis. The current cultural, genetic and paleoanthropological evidence is reviewed, as well as other germane factors, such as the role of neurodegenerative pathologies, the neotenization of humans in their most recent evolutionary history, and the question of cultural selection-based self-domestication. This comprehensive reassessment leads to a paradigmatic shift in the way recent human evolution needs to be viewed. This article explains fully how humans became what they are today.

  12. The Origins Space Telescope (OST)

    Science.gov (United States)

    Staguhn, Johannes

    2018-01-01

    The Origins Space Telescope is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies to be submitted by NASA Headquarters to the 2020 Astronomy and Astrophysics Decadal survey. The observatory will provide orders of magnitude improvements in sensitivity over prior missions, in particular for spectroscopy, enabling breakthrough science across astrophysics. The observatory will cover a wavelength range between 5 μm and 600 μm in order to enable the study of the formation of proto-planetary disks, detection of bio-signatures from extra-solar planet's atmospheres, characterization of the first galaxies in the universe, and many more. The five instruments that are currently studied are two imaging far-infrared spectrometers using incoherent detectors, providing up to R 10^5 spectral resolution, one far-infrared infrared heterodyne instrument for even higher spectral resolving powers, one far-infrared continuum imager and polarimeter, plus a mid-infrared coronagraph with imaging and spectroscopy mode. I will describe the scientific and technical capabilities of the observatory with focus on the expected synergies with AtLAST.

  13. Darwin's Book: On the Origin of Species

    Science.gov (United States)

    Hodge, Jonathan

    2013-09-01

    This essay is an interpretation of Charles Darwin's Origin of Species. It focuses on the contents of the Origin as Darwin intended them to be understood and the background to the work, thus revealing the originality (or otherwise) of the work.

  14. Cosmic ray origin: the way ahead

    International Nuclear Information System (INIS)

    Wolfendale, A W

    2003-01-01

    Despite their discovery being 90 years ago cosmic rays are still characterised by their uncertain masses at high energy and their uncertain origin. This paper deals with the origin problem. The case is put for the majority of the particles being of galactic origin - a generally accepted result. Specific models are put forward for the galactic mechanism and that for the minority extragalactic component

  15. Becoming original : Effects of strategy instruction

    NARCIS (Netherlands)

    van de Kamp, M.-T.; Admiraal, W.; Rijlaarsdam, G.

    2016-01-01

    Visual arts education focuses on creating original visual art products. A means to improve originality is enhancement of divergent thinking, indicated by fluency, flexibility and originality of ideas. In regular arts lessons, divergent thinking is mostly promoted through brainstorming. In a previous

  16. 46 CFR 503.54 - Original classification.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 9 2010-10-01 2010-10-01 false Original classification. 503.54 Section 503.54 Shipping... Program § 503.54 Original classification. (a) No Commission Member or employee has the authority to... classification, it shall be sent to the appropriate agency with original classification authority over the...

  17. 22 CFR 9.4 - Original classification.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Original classification. 9.4 Section 9.4 Foreign Relations DEPARTMENT OF STATE GENERAL SECURITY INFORMATION REGULATIONS § 9.4 Original classification. (a) Definition. Original classification is the initial determination that certain information...

  18. 5 CFR 1201.2 - Original jurisdiction.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Original jurisdiction. 1201.2 Section 1201.2 Administrative Personnel MERIT SYSTEMS PROTECTION BOARD ORGANIZATION AND PROCEDURES PRACTICES AND PROCEDURES Jurisdiction and Definitions § 1201.2 Original jurisdiction. The Board's original...

  19. 46 CFR 67.70 - Original owner.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Original owner. 67.70 Section 67.70 Shipping COAST GUARD... Acceptable Title Evidence; Waiver § 67.70 Original owner. The builder's certification described in § 67.99 serves as evidence of the original owner's title to a vessel. ...

  20. 5 CFR 2500.3 - Original classification.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Original classification. 2500.3 Section... SECURITY REGULATION § 2500.3 Original classification. No one in the Office of Administration has been granted authority for original classification of information. ...

  1. 21 CFR 814.104 - Original applications.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Original applications. 814.104 Section 814.104...) MEDICAL DEVICES PREMARKET APPROVAL OF MEDICAL DEVICES Humanitarian Use Devices § 814.104 Original... applicant. (d) Address for submissions and correspondence. Copies of all original HDEs amendments and...

  2. Becoming Original: Effects of Strategy Instruction

    Science.gov (United States)

    van de Kamp, Marie-Thérèse; Admiraal, Wilfried; Rijlaarsdam, Gert

    2016-01-01

    Visual arts education focuses on creating original visual art products. A means to improve originality is enhancement of divergent thinking, indicated by fluency, flexibility and originality of ideas. In regular arts lessons, divergent thinking is mostly promoted through brainstorming. In a previous study, we found positive effects of an explicit…

  3. Origin of hominids: European or African origin, neither or both?

    Directory of Open Access Journals (Sweden)

    Senut, B.

    2011-12-01

    Full Text Available For the last twenty years, some scientists have suggested that the African ape and humans lineages emerged in Europe, a scenario known as the “Back to Africa Hypothesis”. Even though hominoids were widespread in Eurasia during the Middle and Upper Miocene due to the tropical conditions which prevailed in this region, we cannot dismiss the fact that they were present in Africa (contra some authors. Actually, they were highly diverse at that same time (at least 10 lineages represented even if the fossil record is less complete than in Eurasia. Postcranial elements from African species suggest that some features of modern hominoids were already present in the Lower and Middle Miocene of Africa and were not restricted to European ones. Considering the available evidence, it is not possible at this stage to favour a European origin over an African one. Hominoids were living in the tropical areas of Northern Africa and Southern Eurasia and faunal exchanges between the two continents occurred throughout the Middle and Upper Miocene, as the Tethys did not act as an effective barrier to interchanges between Europe and Asia.

    Durante los últimos veinte años, algunos científicos han sugerido que los grandes monos africanos y los linajes humanos surgieron en Europa, un escenario conocido como la “ Hipótesis de la vuelta a Africa”. A pesar de que los homínidos se extendieron en Eurasia durante el Mioceno Medio y Superior debido a las condiciones tropicales que prevalecian en esta region, no podemos descartar el hecho de que ellos estuvieron presentes en Africa (contra algunos autores. En realidad, ellos tuvieron una alta diversidad al mismo tiempo (al menos 10 líneas representadas, incluso si el registro fosil es menos completo que el de Eurasia. Elementos postcraneales de especies africanas sugieren que en algunos carácteres los homínidos modernos estaban ya presentes en el Mioceno Inferior y Medio de Africa, no sólo restringidos a

  4. [The origin of informed consent].

    Science.gov (United States)

    Mallardi, V

    2005-10-01

    The principle of informed consent, aimed at the lawfulness of health assistance, tends to reflect the concept of autonomy and of decisional autodetermination of the person requiring and requesting medical and/or surgical interventions. This legal formula, over the last few years, has gained not only considerable space but also importance in the doctrinal elaboration and approaches, as well as juridical interpretations, thereby influencing the everyday activities of the medical profession. Informed consent is still the object of continuous explorations, not only asfar as concerns the already confirmed theoretical profile but, instead, the ambiguous practical and consequential aspect. Analysing how the concept and role of consensus was born and developed with the more adequate and reasonable excursions to make it valid and obtain it, it is impossible not to take into consideration, on the one hand, the very ancient philosophical origins and, on the other, the fact that it was conditioned by religion with the moral aspects and the accelerated deontological evolution with pathways parallel to the needs and the progress offered by new forms of treatment and novel biotechnological applications. The principle of consent is a relatively new condition. In fact, already in the times of not only the Egyptian civilisation, but also the Greek and Roman, documents have been found which show how the doctor's intervention had, in some way, first to be approved by the patient. Plato (law IV) had already foreseen the problems, the procedures and the modes of information which are, in synthesis, at the root of the principles of the present formula of informed consent and correlated the practice of the information and consensus with the quality and social position of the patient. The only guarantee that the patient might have, derived from a fundamental principle of medicine of all times: "in disease, focus on two aims, to improve and not to cause damage". A figure can be recognised

  5. Structural Origins of Silk Piezoelectricity.

    Science.gov (United States)

    Yucel, Tuna; Cebe, Peggy; Kaplan, David L

    2011-02-22

    Uniaxially oriented, piezoelectric silk films were prepared by a two-step method that involved: (1) air drying aqueous, regenerated silk fibroin solutions into films, and (2) drawing the silk films to a desired draw ratio. The utility of two different drawing techniques, zone drawing and water immersion drawing were investigated for processing the silk for piezoelectric studies. Silk films zone drawn to a ratio of λ= 2.7 displayed relatively high dynamic shear piezoelectric coefficients of d(14) = -1.5 pC/N, corresponding to over two orders of magnitude increase in d(14) due to film drawing. A strong correlation was observed between the increase in the silk II, β-sheet content with increasing draw ratio measured by FTIR spectroscopy (C(β)∝ e(2.5) (λ)), the concomitant increasing degree of orientation of β-sheet crystals detected via WAXD (FWHM = 0.22° for λ= 2.7), and the improvement in silk piezoelectricity (d(14)∝ e(2.4) (λ)). Water immersion drawing led to a predominantly silk I structure with a low degree of orientation (FWHM = 75°) and a much weaker piezoelectric response compared to zone drawing. Similarly, increasing the β-sheet crystallinity without inducing crystal alignment, e.g. by methanol treatment, did not result in a significant enhancement of silk piezoelectricity. Overall, a combination of a high degree of silk II, β-sheet crystallinity and crystalline orientation are prerequisites for a strong piezoelectric effect in silk. Further understanding of the structural origins of silk piezoelectricity will provide important options for future biotechnological and biomedical applications of this protein.

  6. The origin of vertebrate limbs.

    Science.gov (United States)

    Coates, M I

    1994-01-01

    The earliest tetrapod limbs are polydactylous, morphologically varied and do not conform to an archetypal pattern. These discoveries, combined with the unravelling of limb developmental morphogenetic and regulatory mechanisms, have prompted a re-examination of vertebrate limb evolution. The rich fossil record of vertebrate fins/limbs, although restricted to skeletal tissues, exceeds the morphological diversity of the extant biota, and a systematic approach to limb evolution produces an informative picture of evolutionary change. A composite framework of several phylogenetic hypotheses is presented incorporating living and fossil taxa, including the first report of an acanthodian metapterygium and a new reconstruction of the axial skeleton and caudal fin of Acanthostega gunnari. Although significant nodes in vertebrate phylogeny remain poorly resolved, clear patterns of morphogenetic evolution emerge: median fin origination and elaboration initially precedes that of paired fins; pectoral fins initially precede pelvic fin development; evolving patterns of fin distribution, skeletal tissue diversity and structural complexity become decoupled with increased taxonomic divergence. Transformational sequences apparent from the fish-tetrapod transition are reiterated among extant lungfishes, indicating further directions for comparative experimental research. The evolutionary diversification of vertebrate fin and limb patterns challenges a simple linkage between Hox gene conservation, expression and morphology. A phylogenetic framework is necessary in order to distinguish shared from derived characters in experimental model regulatory systems. Hox and related genomic evolution may include convergent patterns underlying functional and morphological diversification. Brachydanio is suggested as an example where tail-drive patterning demands may have converged with the regulation of highly differentiated limbs in tetrapods.

  7. The origin of ambling horses.

    Science.gov (United States)

    Wutke, Saskia; Andersson, Leif; Benecke, Norbert; Sandoval-Castellanos, Edson; Gonzalez, Javier; Hallsson, Jón Hallsteinn; Lõugas, Lembi; Magnell, Ola; Morales-Muniz, Arturo; Orlando, Ludovic; Pálsdóttir, Albína Hulda; Reissmann, Monika; Muñoz-Rodríguez, Mariana B; Ruttkay, Matej; Trinks, Alexandra; Hofreiter, Michael; Ludwig, Arne

    2016-08-08

    Horseback riding is the most fundamental use of domestic horses and has had a huge influence on the development of human societies for millennia. Over time, riding techniques and the style of riding improved. Therefore, horses with the ability to perform comfortable gaits (e.g. ambling or pacing), so-called 'gaited' horses, have been highly valued by humans, especially for long distance travel. Recently, the causative mutation for gaitedness in horses has been linked to a substitution causing a premature stop codon in the DMRT3 gene (DMRT3_Ser301STOP) [1]. In mice, Dmrt3 is expressed in spinal cord interneurons and plays an important role in the development of limb movement coordination [1]. Genotyping the position in 4396 modern horses from 141 breeds revealed that nowadays the mutated allele is distributed worldwide with an especially high frequency in gaited horses and breeds used for harness racing [2]. Here, we examine historic horse remains for the DMRT3 SNP, tracking the origin of gaitedness to Medieval England between 850 and 900 AD. The presence of the corresponding allele in Icelandic horses (9(th)-11(th) century) strongly suggests that ambling horses were brought from the British Isles to Iceland by Norse people. Considering the high frequency of the ambling allele in early Icelandic horses, we believe that Norse settlers selected for this comfortable mode of horse riding soon after arrival. The absence of the allele in samples from continental Europe (including Scandinavia) at this time implies that ambling horses may have spread from Iceland and maybe also the British Isles across the continent at a later date. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Origins of galactic spiral structures

    International Nuclear Information System (INIS)

    Piddington, J.H.

    1978-01-01

    Theories of galactic structure are reviewed briefly before comparing them with recent observations. Also reviewed is the evidence for an intergalactic magnetic field and its possible effects on gas concentrations and patterns of star creation, including spiral arms. It is then shown that normal spiral galaxies may be divided into the M51-type and others. The rare M51-type have H I gas arms coincident with unusually filamentary and luminous optical arms; they also have a companion galaxy. The remaining great majority of spirals have no well-defined gas arms and their optical arms are irregular, broader and less luminous; they have no companion galaxy. It appears that without exception the half-dozen or so galaxies whose structures appear to support the density-wave theory show one or more of the characteristics of the rare type of spiral, and that 'the three principal confirmations of the spiral-wave idea' (M51, M81, M101) have companions which may account for their arms. Toomre has rejected this idea on the grounds that his models do not agree with the observed structures. It is shown that these models are inadequate in two major respects, and when replaced by magneto-tidal models using non-uniform gas disks one might expect agreement. The original hydromagnetic model of spiral arms is now reserved for non-interacting galaxies, of which M33 might be taken as a prototype. The model predicts broad or 'massive' optical arms and no corresponding arms of neutral hydrogen, as observed. (Auth.)

  9. Mapping replication origins in yeast chromosomes.

    Science.gov (United States)

    Brewer, B J; Fangman, W L

    1991-07-01

    The replicon hypothesis, first proposed in 1963 by Jacob and Brenner, states that DNA replication is controlled at sites called origins. Replication origins have been well studied in prokaryotes. However, the study of eukaryotic chromosomal origins has lagged behind, because until recently there has been no method for reliably determining the identity and location of origins from eukaryotic chromosomes. Here, we review a technique we developed with the yeast Saccharomyces cerevisiae that allows both the mapping of replication origins and an assessment of their activity. Two-dimensional agarose gel electrophoresis and Southern hybridization with total genomic DNA are used to determine whether a particular restriction fragment acquires the branched structure diagnostic of replication initiation. The technique has been used to localize origins in yeast chromosomes and assess their initiation efficiency. In some cases, origin activation is dependent upon the surrounding context. The technique is also being applied to a variety of eukaryotic organisms.

  10. Modern human origins: progress and prospects.

    OpenAIRE

    Stringer, Chris

    2002-01-01

    The question of the mode of origin of modern humans (Homo sapiens) has dominated palaeoanthropological debate over the last decade. This review discusses the main models proposed to explain modern human origins, and examines relevant fossil evidence from Eurasia, Africa and Australasia. Archaeological and genetic data are also discussed, as well as problems with the concept of 'modernity' itself. It is concluded that a recent African origin can be supported for H. sapiens, morphologically, be...

  11. 75 FR 735 - Original Classification Authority

    Science.gov (United States)

    2010-01-05

    ... classify information originally as ``Top Secret'' or ``Secret'': TOP SECRET Executive Office of the... Space Administration The Director, Information Security Oversight Office SECRET Executive Office of the...

  12. Schwannoma Originating From the Periphereral Intercostal Nerves

    Directory of Open Access Journals (Sweden)

    Yunus Aksoy

    2017-06-01

    Full Text Available Schwannomas are usually solitary, encapsulated, and asymptomatic, benign neurogenic tumors originating from the nerve sheath. Schwannomas rarely show malignant transformation, however, require close monitoring. They are primarily located in the thorax in the costovertebral sulcus, may rarely originate from peripheral intercostal nerves. Less than 10% of primary thoracic neurogenic tumors originate from the peripheral intercostal nerves. The main treatment and diagnosis of schwannomas are complete surgical resection. We report a rare case of a 40-year-old male with asymptomatic schwannoma originating from an intercostal nerve which was found incidentally on his chest X-ray and was treated with surgery.

  13. Country of origin effect on brand perception

    DEFF Research Database (Denmark)

    Iacob, Andreea

    2016-01-01

    During the past two decades there has been a substantial amount of empirical evidence on the country of origin phenomenon. However, marketing scholars have different perspectives and views on how the country of origin effect has impacted the brand perceptions of consumers. This paper presents...... an extensive review of the literature on the COO effect and traces the conceptual development of the country-of-origin construct in order to provide scholars and practitioners with a critical appraisal of the existing research on this topic. By following the grounds of the systematic literature, this study...... seeks to establish a solid base for country-of-origin research review....

  14. The Halo Model of Origin Images

    DEFF Research Database (Denmark)

    Josiassen, Alexander; Lukas, Bryan A.; Whitwell, Gregory J.

    2013-01-01

    National origin has gained importance as a marketing tool for practitioners to sell their goods and services. However, because origin-image research has been troubled by several fundamental limitations, academia has become sceptical of the current status and strategic implications of the concept....... The aim of this paper was threefold, namely, to provide a state-of-the-art review of origin-image research in marketing, develop and empirically test a new origin-image model and, present the implications of the study....

  15. Consumer ethnocentrism and Country of origin effect

    DEFF Research Database (Denmark)

    Iacob, Andrea Ioana

    The research on consumer ethnocentrism and country of origin effect is quite substantial in the area of consumer research, but there are competing views as to how low involvement products influence and interact with consumer ethnocentrism and country of origin in a transitional market setting...

  16. Origin of comets - implications for planetary formation

    International Nuclear Information System (INIS)

    Weissman, P.R.; Arizona Univ., Tucson)

    1985-01-01

    Primordial and episodic theories for the origin of comets are discussed. The implications of the former type for the origin of the solar system are considered. Candidate sites for the formation of comets are compared. The possible existence of a massive inner Oort cloud is discussed

  17. On the biosynthetic origin of carminic acid

    DEFF Research Database (Denmark)

    Rasmussen, Silas A.; Kongstad, Kenneth T; Khorsand-Jamal, Paiman

    2018-01-01

    provides solid evidence of a polyketide, rather than a shikimate, origin of coccid pigments. Based on the newly identified compounds, we present a detailed biosynthetic scheme that accounts for the formation of carminic acid (CA) in D. coccus and all described coccid pigments which share a flavokermesic...... distribution suggests a common evolutionary origin for the trait in all coccid dye producing insect species....

  18. 31 CFR 575.311 - Iraqi origin.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Iraqi origin. 575.311 Section 575.311 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN... Government of Iraq, or of a business entity located in Iraq. Services of Iraqi origin are not imported into...

  19. 27 CFR 478.44 - Original license.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Original license. 478.44 Section 478.44 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND....44 Original license. (a)(1) Any person who intends to engage in business as a firearms or ammunition...

  20. The Gestural Theory of Language Origins

    Science.gov (United States)

    Armstrong, David F.

    2008-01-01

    The idea that iconic visible gesture had something to do with the origin of language, particularly speech, is a frequent element in speculation about this phenomenon and appears early in its history. Socrates hypothesizes about the origins of Greek words in Plato's satirical dialogue, "Cratylus", and his speculation includes a possible…

  1. The origin of turtles: a paleontological perspective.

    Science.gov (United States)

    Joyce, Walter G

    2015-05-01

    The origin of turtles and their unusual body plan has fascinated scientists for the last two centuries. Over the course of the last decades, a broad sample of molecular analyses have favored a sister group relationship of turtles with archosaurs, but recent studies reveal that this signal may be the result of systematic biases affecting molecular approaches, in particular sampling, non-randomly distributed rate heterogeneity among taxa, and the use of concatenated data sets. Morphological studies, by contrast, disfavor archosaurian relationships for turtles, but the proposed alternative topologies are poorly supported as well. The recently revived paleontological hypothesis that the Middle Permian Eunotosaurus africanus is an intermediate stem turtle is now robustly supported by numerous characters that were previously thought to be unique to turtles and that are now shown to have originated over the course of tens of millions of years unrelated to the origin of the turtle shell. Although E. africanus does not solve the placement of turtles within Amniota, it successfully extends the stem lineage of turtles to the Permian and helps resolve some questions associated with the origin of turtles, in particular the non-composite origin of the shell, the slow origin of the shell, and the terrestrial setting for the origin of turtles. © 2015 Wiley Periodicals, Inc.

  2. Renal artery origins: best angiographic projection angles.

    Science.gov (United States)

    Verschuyl, E J; Kaatee, R; Beek, F J; Patel, N H; Fontaine, A B; Daly, C P; Coldwell, D M; Bush, W H; Mali, W P

    1997-10-01

    To determine the best projection angles for imaging the renal artery origins in profile. A mathematical model of the anatomy at the renal artery origins in the transverse plane was used to analyze the amount of aortic lumen that projects over the renal artery origins at various projection angles. Computed tomographic (CT) angiographic data about the location of 400 renal artery origins in 200 patients were statistically analyzed. In patients with an abdominal aortic diameter no larger than 3.0 cm, approximately 0.5 mm of the proximal part of the renal artery and origin may be hidden from view if there is a projection error of +/-10 degrees from the ideal image. A combination of anteroposterior and 20 degrees and 40 degrees left anterior oblique projections resulted in a 92% yield of images that adequately profiled the renal artery origins. Right anterior oblique projections resulted in the least useful images. An error in projection angle of +/-10 degrees is acceptable for angiographic imaging of the renal artery origins. Patients sex, site of interest (left or right artery), and local diameter of the abdominal aorta are important factors to consider.

  3. Tanzanian food origins and protected geographical indications

    DEFF Research Database (Denmark)

    John, Innocensia Festo; Egelyng, Henrik; Lokina, Azack

    2016-01-01

    As the world's population is constantly growing, food security will remain on the policy Agenda, particularly in Africa. At the same time, global food systems experience a new wave focusing on local foods and food sovereignty featuring high quality food products of verifiable geographical origin...... of food origin products in Tanzania that have potential for GI certification. The hypothesis was that there are origin products in Tanzania whose unique characteristics are linked to the area of production. Geographical indications can be useful policy instruments contributing to food security...... the diversity of supply of natural and unique quality products and so contribute to enhanced food security....

  4. Browsing the Origins of Comic Book Superheroes

    DEFF Research Database (Denmark)

    Andersen, Tem Frank

    2017-01-01

    This article tries to explore and explain the significance of comic book superheroes and their origins stories. The analysis of the two selected case examples from the sociale video sharing site WatchMojo.com focus on four aspects or theme: Comic book hermeneutics, types of origin, subjectivization...... of superheroes, and, user reactions. These analytical themes are based on an approach combining cultural semiotics, comic book superhero studies, studies in participatory culture, cultural studies and media user studies. The analysis presented provide some evidence to the claim, that superhero origins stories...

  5. [Origin and evolution of human immunodeficiency viruses].

    Science.gov (United States)

    Marian, Constantin V

    2009-01-01

    After the diagnosis of the AIDS symptoms, in 1981, and after the discovery of the virus that causes AIDS, in 1983, the virologists have formulated different theories about its origin. Some of them involved natural causes, e.g., HIV origin from SIV strains. Other theories go further to the possibility of a deadly man-made virus escaped from laboratories or voluntary spread by some conspirative organisations. At this moment, the scientists limits themselves to search proofs to sustain the zoonotic origin of HIV from SIV and its accomodation to human body conditions.

  6. Quality of original and biosimilar epoetin products.

    Science.gov (United States)

    Brinks, Vera; Hawe, Andrea; Basmeleh, Abdul H H; Joachin-Rodriguez, Liliana; Haselberg, Rob; Somsen, Govert W; Jiskoot, Wim; Schellekens, Huub

    2011-02-01

    To compare the quality of therapeutic erythropoietin (EPO) products, including two biosimilars, with respect to content, aggregation, isoform profile and potency. Two original products, Eprex (epoetin alpha) and Dynepo (epoetin delta), and two biosimilar products, Binocrit (epoetin alpha) and Retacrit (epoetin zeta), were compared using (1) high performance size exclusion chromatography, (2) ELISA, (3) SDS-PAGE, (4) capillary zone electrophoresis and (5) in-vivo potency. Tested EPO products differed in content, isoform composition, and potency. Of the tested products, the biosimilars have the same or even better quality as the originals. Especially, the potency of originals may significantly differ from the value on the label.

  7. On origin of mass and supersymmetry

    OpenAIRE

    Shima, Kazunari; Tsuda, Motomu

    2007-01-01

    We show that the nonlinear supersymmetric general relativity gives new insights into the origin of mass and elucidates the mysterious relations between the cosmology and the (low energy) particle physics.

  8. New Step Underground in Universe Origins Quest

    CERN Document Server

    Evans, Robert

    2003-01-01

    Europe's top particle physics research center has taken a major step in its plan to build the world's biggest "particle smasher" which it hopes will eventually unlock the secrets of the origins of the universe (½ page)

  9. Dynamics of comets: their origin and evolution

    International Nuclear Information System (INIS)

    Carusi, A.; Valsecchi, G.B.

    1985-01-01

    Comets can be considered as remnants of the original population of planetesimals and the study of their origin and dynamical histories can provide insight into the accretion phenomena; the original mass, energy and angular momentum distribution across the solar system; the collisional fragmentation of minor bodies; the impact rates on planets and the nature of impacting bodies. The interaction of comets with other solar system bodies certainly provides one of the best possibilities for a deeper understanding of the dynamics of the whole system, and a challenging test for all theories of celestial mechanics dealing with the gravitational behaviour of multiple-body systems. Comets could also be considered as the last footprints left by the interaction of the protosun and its original galactic environment. (orig.)

  10. ORIGINAL ARTICLE Sonographic gallbladder wall thickness in ...

    African Journals Online (AJOL)

    Ramadan period, which assisted in compliance with fasting. The clinical parameters ... ORIGINAL ARTICLE adequate depth penetration, and is suitable for obese subjects. A 5.0 ... group difference for continuous variables. Chi-square and ...

  11. God particle and origin of mass

    International Nuclear Information System (INIS)

    He Hongjian; Kuang Yuping

    2014-01-01

    The new Higgs boson discovered at the CERN LHC could be the God particle expected from the standard model. This revolutionary discovery opens up a new era of exploring the origin of masses for all elementary particles in the universe. It becomes a turning point of the particle physics in 21 th century. This article presents the following: (1) Scientific importance of searching and testing the God particle(s); (2) The history of studying the origin of mass, and why Newton mechanics and Einstein relativity could not resolve the origin of mass; (3) The mysterious vacuum and the mechanism of spontaneous symmetry breaking; (4) How the God particle was invented and how the LHC might have discovered it; (5) The perspective of seeking the origin of mass and new physics laws. (authors)

  12. Early Planetary Environments and the Origin of

    Indian Academy of Sciences (India)

    Archaean-Hadean oceans releasing Hz- The solar flux in the. Hadean and ... universe. However, Rikken and Raupach (2000) have demonstrated that static magnetic field can bias .... origin of life is ho~ did such an interdependent system of.

  13. Origin of the Chernobyl myths and stereotypes

    International Nuclear Information System (INIS)

    Bashilov, A.V.; Borisevich, N.Ya.; Sobolev, O.V.

    2013-01-01

    The article describes the origin of main negative Chernobyl myths and stereotypes in Belarus' society which do not meet the reality, hinder the revival and development processes of affected territories. (authors)

  14. ORIGINAL ARTICLE An Assessment of Mathematics Classroom ...

    African Journals Online (AJOL)

    Bdu

    ORIGINAL ARTICLE. An Assessment of Mathematics Classroom Teaching- ... the study was to assess whether the learning classroom environment was compliant with constructivism. ... of our education system. Applefield ... share control of the design, management, and evaluation ..... development of formative assessment.

  15. Origin and domestication of Lactuca sativa L.

    NARCIS (Netherlands)

    Vries, de I.M.

    1997-01-01

    The domestication of lettuce, Lactuca sativa L. is described on the basis of literature study. The centre of origin is discussed. A historical survey is made of the distribution of the groups of Lactuca cultivars over the world.

  16. ORIGINAL ARTICLES Academic hospital accreditation strengthens ...

    African Journals Online (AJOL)

    This case study originated from the combined experiences of the accreditation process of a ... (iv) the benefits of hospital accreditation and quality management. The study ... Tertiary healthcare is in a crisis after nearly 3 decades of neglect,2,3.

  17. Original Research Rotavirus antigen, cytokine, and neutralising ...

    African Journals Online (AJOL)

    Department of Clinical Infection, Microbiology and Immunology; University of Liverpool, Liverpool, United Kingdom. 3. .... onset of illness.10 However, we were unable to find original records and thus ..... position paper, 2013:p. 49–64. 12.

  18. The Solar System and Its Origin

    Science.gov (United States)

    Dormand, J. R.

    1973-01-01

    Presents a brief explanation of the solar system, including planets, asteroids, satellites, comets, planetary orbits, as well as, old and recent cosmogonic theories. Indicates that man is nearer a solution to the origin of the planetary system than ever before.

  19. Quality of Original and Biosimilar Epoetin Products

    NARCIS (Netherlands)

    Brinks, V.|info:eu-repo/dai/nl/31395979X; Hawe, A.; Basmeleh, A.H.H.|info:eu-repo/dai/nl/337907331; Joachin-Rodriguez, L.; Haselberg, R.|info:eu-repo/dai/nl/304822647; Somsen, G.W.|info:eu-repo/dai/nl/117149357; Jiskoot, W.|info:eu-repo/dai/nl/084557397; Schellekens, H.|info:eu-repo/dai/nl/068406762

    2011-01-01

    Purpose: To compare the quality of therapeutic erythropoietin (EPO) products, including two biosimilars, with respect to content, aggregation, isoform profile and potency. Methods: Two original products, Eprex (epoetin alfa) and Dynepo (epoetin delta), and two biosimilar products, Binocrit (epoetin

  20. Is supersymmetric origin of monojets viable

    International Nuclear Information System (INIS)

    Nandi, S.

    1985-01-01

    The laboratory and cosmological bounds on the masses of the scalar leptons and the photino are used to put constraints on the supersymmetric origin of the CERN monojets. The latest MAC data at PEP exclude the scalar quarks, of masses up to 45 GeV, as the origin of these monojets; the cosmological bounds, for a stable photino, exclude the mass range necessary for the gq production interpretation

  1. Rules of Origin as Commercial Policy Instruments.

    OpenAIRE

    Falvey, Rod; Reed, Geoff

    1997-01-01

    This article examines the role of rules of origin as a commercial policy instrument that targets the input composition of imports. Using a three-country, partial equilibrium structure, we demonstrate conditions under which the imposition of a binding rule will be welfare improving for an importer facing competitive export suppliers. We further show that employing rules of origin in this way would be complementary to, rather than a substitute for, conventional optimal tariffs. Copyright Econom...

  2. NIRS database of the original research database

    International Nuclear Information System (INIS)

    Morita, Kyoko

    1991-01-01

    Recently, library staffs arranged and compiled the original research papers that have been written by researchers for 33 years since National Institute of Radiological Sciences (NIRS) established. This papers describes how the internal database of original research papers has been created. This is a small sample of hand-made database. This has been cumulating by staffs who have any knowledge about computer machine or computer programming. (author)

  3. Generational Variations in Mexican-Origin Intermarriage

    OpenAIRE

    Cedillo, Rosalio

    2015-01-01

    This dissertation examines intermarriage across generations of the Mexican-origin population in order to better understand how this population is incorporating in U.S. society, and looks at parental migration status and parental nativity as factors that may impede or facilitate intermarriage incorporation. Using data from the Immigration and Intergenerational Mobility in Metropolitan Los Angeles (IIMMLA) survey the research shows that: the majority of intermarriages among the Mexican-origin ...

  4. Origin of stars and structure of galaxies

    International Nuclear Information System (INIS)

    Palous, J.

    1988-01-01

    The substance is described of molecular clouds from interstellar mass and the origin, process and termination of the gravitational collapse are described which lead to the creation of stars. The probability is described of the origin of high-mass and lower-mass stars. The connection is discussed between the creation of stars, molecular clouds and the structure of galaxies. (E.S.). 7 figs

  5. Upheaval Dome, Utah, USA: Impact Origin Confirmed

    OpenAIRE

    Buchner, Elmar; Kenkmann, Thomas

    2008-01-01

    Upheaval Dome is a unique circular structure on the Colorado Plateau in SE Utah, the origin of which has been controversially discussed for decades. It has been interpreted as a crypto volcanic feature, a salt diapir, a pinched-off salt diapir, and an eroded impact crater. While recent structural mapping, modeling, and analyses of deformation mechanisms strongly support an impact origin, ultimate proof, namely the documentation of unambiguous shock features, has yet to be successfully provide...

  6. The origin of the elements. Chapter 3

    International Nuclear Information System (INIS)

    Tayler, R.J.

    1980-01-01

    The paper is concerned with the questions: how the present chemical composition is related to the original composition of the Universe, and what was the nature of that original composition. In particular, the chemical evolution of the Galaxy is discussed. Section headings are: observations of chemical composition (stars, cosmic gases, galaxies, element abundance); theoretical considerations (nucleosynthesis); cosmological element production (the Hot Big Bang theory); galactic nucleosynthesis. (U.K.)

  7. The origins of language in teaching.

    Science.gov (United States)

    Laland, Kevin N

    2017-02-01

    I introduce seven criteria for determining the validity of competing theories for the original function of language. I go on to present a novel explanation that meets all the criteria: language originally evolved to teach kin. I suggest that the use of symbols subsequently generated evolutionary feedback at two levels, in the form of self-modified selection pressures that favored structures in the mind that functioned to manipulate and use symbols with efficiency, and cultural selection on languages for learnability.

  8. Luna 24 origins: some trace element constraints

    International Nuclear Information System (INIS)

    Jovanovic, S.; Jensen, K.J.; Reed, G.W. Jr.

    1978-01-01

    Luna 24 basaltic material originated in the particular volume of the lunar crust that produced Apollo 11 and Luna 16 basaltic material; it has the same Cl/sub r//P 2 O 5 signature. Ru--Os contents (Barsukov et al., 1977) and a number of radiogenic age measurements place Luna 24 basalt origins stratigraphically in a layer between those from which Apollo 15 and Apollo 11 and 17 basalts were derived. 20 references

  9. The origin of the universe. Chapter 1

    International Nuclear Information System (INIS)

    Sciama, D.W.

    1980-01-01

    The observational and theoretical evidence in favour of the Big Bang origin, and the question whether an actually singular origin of the universe can be avoided, are discussed. Sections are headed: the world of galaxies (main facts about galaxies); the recession of the galaxies (red-shift, Hubble's law); the cosmic black body background (behaviour of the Universe in its hot early epochs, nuclear reactions, abundance of hydrogen, helium and deuterium). (U.K.)

  10. Contextualising primate origins--an ecomorphological framework.

    Science.gov (United States)

    Soligo, Christophe; Smaers, Jeroen B

    2016-04-01

    Ecomorphology - the characterisation of the adaptive relationship between an organism's morphology and its ecological role - has long been central to theories of the origin and early evolution of the primate order. This is exemplified by two of the most influential theories of primate origins: Matt Cartmill's Visual Predation Hypothesis, and Bob Sussman's Angiosperm Co-Evolution Hypothesis. However, the study of primate origins is constrained by the absence of data directly documenting the events under investigation, and has to rely instead on a fragmentary fossil record and the methodological assumptions inherent in phylogenetic comparative analyses of extant species. These constraints introduce particular challenges for inferring the ecomorphology of primate origins, as morphology and environmental context must first be inferred before the relationship between the two can be considered. Fossils can be integrated in comparative analyses and observations of extant model species and laboratory experiments of form-function relationships are critical for the functional interpretation of the morphology of extinct species. Recent developments have led to important advancements, including phylogenetic comparative methods based on more realistic models of evolution, and improved methods for the inference of clade divergence times, as well as an improved fossil record. This contribution will review current perspectives on the origin and early evolution of primates, paying particular attention to their phylogenetic (including cladistic relationships and character evolution) and environmental (including chronology, geography, and physical environments) contextualisation, before attempting an up-to-date ecomorphological synthesis of primate origins. © 2016 Anatomical Society.

  11. How to write an original article.

    Science.gov (United States)

    Mateu Arrom, L; Huguet, J; Errando, C; Breda, A; Palou, J

    2018-05-17

    A correctly drafted original article gives information on what was done, why it was done, how it was done, the result of what was done, and the significance of what was done. Many articles fail to report their results effectively. To describe the characteristics of an original article and to give practical recommendations to prevent the most common errors in our environment. We performed a systematic search of the terms "how to write a scientific article", "structure of the original article" and "publishing an article" in the databases PubMed and SCOPUS. We analysed the structure of an original article and the characteristics of its parts and prepared advice on the publication of an article. The journal's guidelines for authors should be read. It is usual for the original article to follow the IMRAD structure: Introduction, Methods, Results and Discussion. The introduction states briefly why the study was performed. The methods' section should give a detailed explanation of how the study was performed. The results should be clearly presented, with the help of tables, without repeating information. The discussion explains the relevance of the results and contrasts them with those of other authors. Any limitations and a conclusion supported by the results must be included. Writing an original article correctly requires practice and it must be supported by a good research work in order to be published. Copyright © 2018 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. A Review of Ideas Concerning Life Origin

    Science.gov (United States)

    Gindilis, L. M.

    2014-10-01

    Since the times of Antiquity the and for a long time the idea of self-origination of life was the dominant one. It reappeared again after microorganisms were discovered (XVII century). The possibility of abiogenesis at microbial level was discussed for more than a century. Pateur demonstrated that spontaneous origination of microorganisms in sterile broth was due to those same microorganisms transported by dust particles. Thus proving that every form of life originates from the parental life form. So the question arises: how did the first microorganisms appear on the Earth. There are three possible versions: 1) accidental origination of a viable form; 2) primal organisms were transported to the Earth from outer space; 3) they were formed on the Earth in the process of prebiotic chemical evolution. We discuss the problems of prebiotic evolution from simple monomers up to living cells. An important item of nowadays conceptions of life origination is the hypothesis of the ancient world of RNA as possible precursor of life on Earth. The discovery in carbonaceous chondrites of traces of bacterial life evidences the existence of life in the Solar System even before the formation of the Earth. The idea of life as brought to the Earth out of Cosmos originated under the impression of self-origination hypothesis downfall. It went through several stages (Helmholtz, W. Thompson, XIX century; Arrhenius, early XX century; Hoyle and Wickramasinghe, second half of XX century) and presently evokes constantly growing interest. The panspermia theory does not solve the problem of origination of life, only moves it onto other planets. According to V.A. Mazur, the probability of accidental formation of RNA molecule is negligible not only on the Earth, but in the whole Universe over all the time span of its existence. But it is practically equal to unit in the domain formed at the inflation stage of the evolution of the Universe. A.D.Panov considered panspermia in the Galaxy at the level

  13. Words of foreign origin in political discourse

    Directory of Open Access Journals (Sweden)

    Sabina Zorčič

    2012-12-01

    Full Text Available The paper discusses the use of words of foreign origin in Slovenian political discourse. At the outset, this usage is broken down into four groups: the first contains specific phrases and terminology inherent to the political domain; the second contains words of foreign origin generally present in the Slovene language (because of their high frequency of nonexclusivistic use, these words are not of interest to the scope of this investigation; the third contains various words of foreign origin used as affectional packaging for messages with the aim of stimulating the desired interpretation (framing reality; the fourth group, which is the most interesting for our research, is made up of words of foreign origin which could have a marker: + marked, + not necessary, + unwanted, but only if we accept the logic of purism. All the words in this group could be replaced - without any loss of meaning - with their Slovene equivalents. The speakerʼs motivation for using the foreign word is crucial to our discussion. In the framework of Pierre Bourdieuʼs poststructural theory as well as Austinʼs and Searleʼs speech act theory, statistical data is analysed to observe how usage frequency varies in correlation with selected factors which manifest the speakerʼs habitus. We argue that words of foreign origin represent symbolic cultural capital, a kind of added value which functions as credit and as such is an important form of the accumulation of capital.

  14. Origin of life in a digital microcosm

    Science.gov (United States)

    C G, Nitash; LaBar, Thomas; Hintze, Arend; Adami, Christoph

    2017-11-01

    While all organisms on Earth share a common descent, there is no consensus on whether the origin of the ancestral self-replicator was a one-off event or whether it only represented the final survivor of multiple origins. Here, we use the digital evolution system Avida to study the origin of self-replicating computer programs. By using a computational system, we avoid many of the uncertainties inherent in any biochemical system of self-replicators (while running the risk of ignoring a fundamental aspect of biochemistry). We generated the exhaustive set of minimal-genome self-replicators and analysed the network structure of this fitness landscape. We further examined the evolvability of these self-replicators and found that the evolvability of a self-replicator is dependent on its genomic architecture. We also studied the differential ability of replicators to take over the population when competed against each other, akin to a primordial-soup model of biogenesis, and found that the probability of a self-replicator outcompeting the others is not uniform. Instead, progenitor (most-recent common ancestor) genotypes are clustered in a small region of the replicator space. Our results demonstrate how computational systems can be used as test systems for hypotheses concerning the origin of life. This article is part of the themed issue 'Reconceptualizing the origins of life'.

  15. Words of foreign origin in political discourse

    Directory of Open Access Journals (Sweden)

    Sabina Zorčič

    2012-12-01

    Full Text Available The paper discusses the use of words of foreign origin in Slovenian political discourse. At the outset, this usage is broken down into four groups: the first contains specific phrases and terminology inherent to the political domain; the second contains words of foreign origin generally present in the Slovene language (because of their high frequency of nonexclusivistic use, these words are not of interest to the scope of this investigation; the third contains various words of foreign origin used as affectional packaging for messages with the aim of stimulating the desired interpretation (framing reality; the fourth group, which is the most interesting for our research, is made up of words of foreign origin which could have a marker: + marked, + not necessary, + unwanted, but only if we accept the logic of purism. All the words in this group could be replaced - without any loss of meaning - with their Slovene equivalents. The speakerʼs motivation for using the foreign word is crucial to our discussion. In the framework of Pierre Bourdieuʼs poststructural theory as well as Austinʼs and Searleʼs speech act theory, statistical data is analysed to observe how usage frequency varies in correlation with selected factors which manifest the speakerʼs habitus. We argue that words of foreign origin represent symbolic cultural capital, a kind of added value which functions as credit and as such is an important form of the accumulation of capital.       

  16. Original antigenic sin responses to influenza viruses.

    Science.gov (United States)

    Kim, Jin Hyang; Skountzou, Ioanna; Compans, Richard; Jacob, Joshy

    2009-09-01

    Most immune responses follow Burnet's rule in that Ag recruits specific lymphocytes from a large repertoire and induces them to proliferate and differentiate into effector cells. However, the phenomenon of "original antigenic sin" stands out as a paradox to Burnet's rule of B cell engagement. Humans, upon infection with a novel influenza strain, produce Abs against older viral strains at the expense of responses to novel, protective antigenic determinants. This exacerbates the severity of the current infection. This blind spot of the immune system and the redirection of responses to the "original Ag" rather than to novel epitopes were described fifty years ago. Recent reports have questioned the existence of this phenomenon. Hence, we revisited this issue to determine the extent to which original antigenic sin is induced by variant influenza viruses. Using two related strains of influenza A virus, we show that original antigenic sin leads to a significant decrease in development of protective immunity and recall responses to the second virus. In addition, we show that sequential infection of mice with two live influenza virus strains leads to almost exclusive Ab responses to the first viral strain, suggesting that original antigenic sin could be a potential strategy by which variant influenza viruses subvert the immune system.

  17. The precise temporal calibration of dinosaur origins.

    Science.gov (United States)

    Marsicano, Claudia A; Irmis, Randall B; Mancuso, Adriana C; Mundil, Roland; Chemale, Farid

    2016-01-19

    Dinosaurs have been major components of ecosystems for over 200 million years. Although different macroevolutionary scenarios exist to explain the Triassic origin and subsequent rise to dominance of dinosaurs and their closest relatives (dinosauromorphs), all lack critical support from a precise biostratigraphically independent temporal framework. The absence of robust geochronologic age control for comparing alternative scenarios makes it impossible to determine if observed faunal differences vary across time, space, or a combination of both. To better constrain the origin of dinosaurs, we produced radioisotopic ages for the Argentinian Chañares Formation, which preserves a quintessential assemblage of dinosaurian precursors (early dinosauromorphs) just before the first dinosaurs. Our new high-precision chemical abrasion thermal ionization mass spectrometry (CA-TIMS) U-Pb zircon ages reveal that the assemblage is early Carnian (early Late Triassic), 5- to 10-Ma younger than previously thought. Combined with other geochronologic data from the same basin, we constrain the rate of dinosaur origins, demonstrating their relatively rapid origin in a less than 5-Ma interval, thus halving the temporal gap between assemblages containing only dinosaur precursors and those with early dinosaurs. After their origin, dinosaurs only gradually dominated mid- to high-latitude terrestrial ecosystems millions of years later, closer to the Triassic-Jurassic boundary.

  18. Bilateral subclavian origin of the bronchial arteries combined with absence of other origins.

    Science.gov (United States)

    Jie, Bing; Sun, Xi-Wen; Yu, Dong; Jiang, Sen

    2014-08-01

    There are numerous anatomical variations of the sites of origin of the bronchial arteries (BAs). A subclavian origin of a BA involves an aberrant artery that originates from the subclavian artery (SCA) or its branches. However, the aberrant artery usually originates directly from the SCA, and an SCA-origin BA arising from the branches of the SCA is rare. We herein present an extremely rare case of a right BA arising from the ipsilateral costocervical trunk, and a left BA arising from the ipsilateral thyrocervical trunk, in the absence of other origins of the BA. This anatomical variation was detected during pretherapeutic evaluation by multidetector-row computed tomography and confirmed by selective angiography. Recognition of these anatomic variations is important to surgical, diagnostic, and interventional radiologic procedures in the thorax.

  19. Hawaiian propolis: comparative analysis and botanical origin.

    Science.gov (United States)

    Inui, Saori; Hosoya, Takahiro; Kumazaw, Shigenori

    2014-02-01

    Propolis is a resinous mixture of substances collected and processed from various botanical sources by honeybees (Apis mellifera). We recently obtained Hawaiian propolis, the study of which, to our knowledge, has not been reported. The purpose of this study was to analyze the composition of Hawaiian propolis and to identify its botanical origin. A comparative analysis of Hawaiian and Okinawan propolis and of the glandular trichomes on Macaranga tanarius fruit (the botanical origin of Okinawan propolis) was performed using reversed-phase high-performance liquid chromatography coupled with high resolution-electrospray mass spectrometry. Hawaiian propolis contained nine prenylflavonoids that were also isolated from Okinawan propolis. In conclusion, we suggest that the botanical origin of Hawaiian propolis is M. tanarius, the same as that of Okinawan propolis.

  20. Symbiosis and the origin of eukaryotic motility

    Science.gov (United States)

    Margulis, L.; Hinkle, G.

    1991-01-01

    Ongoing work to test the hypothesis of the origin of eukaryotic cell organelles by microbial symbioses is discussed. Because of the widespread acceptance of the serial endosymbiotic theory (SET) of the origin of plastids and mitochondria, the idea of the symbiotic origin of the centrioles and axonemes for spirochete bacteria motility symbiosis was tested. Intracellular microtubular systems are purported to derive from symbiotic associations between ancestral eukaryotic cells and motile bacteria. Four lines of approach to this problem are being pursued: (1) cloning the gene of a tubulin-like protein discovered in Spirocheata bajacaliforniesis; (2) seeking axoneme proteins in spirochets by antibody cross-reaction; (3) attempting to cultivate larger, free-living spirochetes; and (4) studying in detail spirochetes (e.g., Cristispira) symbiotic with marine animals. Other aspects of the investigation are presented.

  1. What is the origin of pancreatic adenocarcinoma?

    Directory of Open Access Journals (Sweden)

    Pandey Krishan K

    2003-01-01

    Full Text Available Abstract The concept of pancreatic cancer origin is controversial. Acinar, ductal or islet cells have been hypothesized as the cell of origin. The pros and cons of each of these hypotheses are discussed. Based on the world literature and recent observations, pancreatic cells seem to have potential for phenotypical transdifferentiation, i.e ductal-islet, ductal-acinar, acinar-ductal, acinar-islet, islet-acinar and islet-ductal cells. Although the possibility is discussed that cancer may arise from either islet, ductal or acinar cells, the circumstances favoring the islet cells as the tumor cell origin include their greater transdifferentiation potency into both pancreatic and extrapancreatic cells, the presence of a variety of carcinogen-metabolizing enzymes, some of which are present exclusively in islet cells and the growth factor-rich environment of islets.

  2. Coronary artery with aberrant origin malignant right

    International Nuclear Information System (INIS)

    Ozcan, E.; Bozlar, U.; Demirkol, S.; Saglam, M.

    2012-01-01

    Full text: Introduction: Congenital anomalies of the coronary arteries is a major cause of sudden death, especially in young patients. Objectives and tasks: In this study we aim to present a young patient with chest pain who had malignant right coronary artery (RCA) with aberrant origin. Materials and methods: 24-year-old man who applied cardiology clinic for chest pain and palpitations especially after exercise, was referred to our clinic for coronary computed tomography (CT) angiography to evaluate coronary artery anomalies. Results: In CT angiography; we detected aberrant RCA with origin of tubularly part of ascendant aorta with a malignant course between aorta and pulmonary artery. Left main coronary artery, left anterior descending and circumflex artery had normal origin and course. Conclusion: Coronary artery with malignant course may cause sudden death especially after exercise. Coronary CT angiography has an important role in diagnosis of congenital coronary artery anomalies, with high resolution multiplanner reformatted images

  3. Planetary Environments and Origins of Life

    Directory of Open Access Journals (Sweden)

    Ollivier Marc

    2014-02-01

    Full Text Available The present strategies proposed for the search for the origins of life and for extra-terrestrial life are mainly based on Earth-life and its adaptation along geological eras to the Earth environment. These strategies should however face the difficulty that one cannot as yet accurately date the appearance of life on Earth, and consequently one cannot identify a chronology of phenomena related to the transition from the non-living to the living and the dependence of these phenomena on the Earth environment. In this paper, we present new approaches to search for the origins of life on the Earth and next, for life on exoplanets. This study is based on our experience gained at the head of the CNRSc interdisciplinary research initiative "Environnements Planétaires et Origines de la Vie (EPOVd, and on the analysis of the projects the initiative funded.

  4. Origins of Life Research: a Bibliometric Approach

    Science.gov (United States)

    Aydinoglu, Arsev Umur; Taşkın, Zehra

    2018-03-01

    This study explores the collaborative nature and interdisciplinarity of the origin(s) of life (OoL) research community. Although OoL research is one of the oldest topics in philosophy, religion, and science; to date there has been no review of the field utilizing bibliometric measures. A dataset of 5647 publications that are tagged as OoL, astrobiology, exobiology, and prebiotic chemistry is analyzed. The most prolific authors (Raulin, Ehrenfreund, McKay, Cleaves, Cockell, Lazcano, etc.), most cited scholars and their articles (Miller 1953, Gilbert 1986, Chyba & Sagan 1992, Wolchtershauser 1988, etc.), and popular journals ( Origins of Life and Evolution of Biospheres and Astrobiology) for OoL research are identified. Moreover, interdisciplinary research conducted through research networks, institutions (NASA, Caltech, University of Arizona, University of Washington, CNRS, etc.), and keywords & concepts (astrobiology, life, Mars, amino acid, prebiotic chemistry, evolution, RNA) are explored.

  5. The origin of the vertebrate skeleton

    Science.gov (United States)

    Pivar, Stuart

    2011-01-01

    The anatomy of the human and other vertebrates has been well described since the days of Leonardo da Vinci and Vesalius. The causative origin of the configuration of the bones and of their shapes and forms has been addressed over the ensuing centuries by such outstanding investigators as Goethe, Von Baer, Gegenbauer, Wilhelm His and D'Arcy Thompson, who sought to apply mechanical principles to morphogenesis. However, no coherent causative model of morphogenesis has ever been presented. This paper presents a causative model for the origin of the vertebrate skeleton, based on the premise that the body is a mosaic enlargement of self-organized patterns engrained in the membrane of the egg cell. Drawings illustrate the proposed hypothetical origin of membrane patterning and the changes in the hydrostatic equilibrium of the cytoplasm that cause topographical deformations resulting in the vertebrate body form.

  6. Origins Of Magnetospheric Physics An Expanded Edition

    CERN Document Server

    Van Allen, James A

    2004-01-01

    Early in 1958, instruments on the space satellites Explorer I and Explorer III revealed the presence of radiation belts, enormous populations of energetic particles trapped in the magnetic field of the earth. Originally published in 1983 but long out of print until now, Origins of Magnetospheric Physics tells the story of this dramatic and hugely transformative period in scientific and Cold War history. Writing in an accessible style and drawing on personal journals, correspondence, published papers, and the recollections of colleagues, James Van Allen documents a trail-blazing era in space hi

  7. Origins of the protein synthesis cycle

    Science.gov (United States)

    Fox, S. W.

    1981-01-01

    Largely derived from experiments in molecular evolution, a theory of protein synthesis cycles has been constructed. The sequence begins with ordered thermal proteins resulting from the self-sequencing of mixed amino acids. Ordered thermal proteins then aggregate to cell-like structures. When they contained proteinoids sufficiently rich in lysine, the structures were able to synthesize offspring peptides. Since lysine-rich proteinoid (LRP) also catalyzes the polymerization of nucleoside triphosphate to polynucleotides, the same microspheres containing LRP could have synthesized both original cellular proteins and cellular nucleic acids. The LRP within protocells would have provided proximity advantageous for the origin and evolution of the genetic code.

  8. Origin, development, and evolution of butterfly eyespots.

    Science.gov (United States)

    Monteiro, Antónia

    2015-01-07

    This article reviews the latest developments in our understanding of the origin, development, and evolution of nymphalid butterfly eyespots. Recent contributions to this field include insights into the evolutionary and developmental origin of eyespots and their ancestral deployment on the wing, the evolution of eyespot number and eyespot sexual dimorphism, and the identification of genes affecting eyespot development and black pigmentation. I also compare features of old and more recently proposed models of eyespot development and propose a schematic for the genetic regulatory architecture of eyespots. Using this schematic I propose two hypotheses for why we observe limits to morphological diversity across these serially homologous traits.

  9. Pregeometric origin of the big bang

    International Nuclear Information System (INIS)

    Akama, K.; Terazawa, H.; Tokyo Univ., Tanashi

    1981-07-01

    The temperature-dependent effective action for gravity is calculated in pregeometry. It indicates that the effective potential for the space-time metric has the minimum at the origin for extremely high temperature. The origin of the big bang can be taken as a local and spontaneous phase transition of the space-time from the pregeometric phase to the geometric one. It is suggested that in our universe there may exist ''pregeometric holes'' where the space-time metric absolutely vanishes and/or ''space-time discontinuities'' where the metric discretely changes. (author)

  10. Cosmic Origins Program Annual Technology Report

    Science.gov (United States)

    Pham, Bruce Thai; Neff, Susan Gale

    2016-01-01

    What is the Cosmic Origins (COR) Program? From ancient times, humans have looked up at the night sky and wondered: Are we alone? How did the universe come to be? How does the universe work? COR focuses on the second question. Scientists investigating this broad theme seek to understand the origin and evolution of the universe from the Big Bang to the present day, determining how the expanding universe grew into a grand cosmic web of dark matter enmeshed with galaxies and pristine gas, forming, merging, and evolving over time.

  11. The origins of the universe for dummies

    CERN Document Server

    Pincock, Stephen

    2007-01-01

    Do you want to learn about the physical origin of the Universe, but don't have the rest of eternity to read up on it? Do you want to know what scientists know about where you and your planet came from, but without the science blinding you? 'Course you do - and who better than For Dummies to tackle the biggest, strangest and most wonderful question there is! The Origins of the Universe For Dummies covers: Early ideas about our universeModern cosmologyBig Bang theoryDark matter and gravityGalaxies and solar systemsLife on earthFi

  12. Protestant Origins of Human Rights Challenged

    Directory of Open Access Journals (Sweden)

    Mogens Chrom Jacobsen

    2017-08-01

    Full Text Available This paper will challenge common views about Protestantism as the originator or foremost promoter of human rights. The idea of a Protestant origin is launched by Georg Jellinek and disputed by Emile Boutmy. The idea is still current and John Witte can thus claim that Protestantism was in part a human rights movement. The point of departure for this strain of thinking is religious toleration, which is seen as a particularly Protestant achievement. We will argue that a more precise notion of what 18th-century human rights were and a closer look at mainstream Protestant political philosophy will tell another story.

  13. 7 CFR 800.117 - Who shall perform original services.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Who shall perform original services. 800.117 Section... REGULATIONS Original Services § 800.117 Who shall perform original services. (a) General. Original services... official agency is not available on a regular basis to provide original services, and no official agency...

  14. 7 CFR 868.44 - New original inspection.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false New original inspection. 868.44 Section 868.44... FOR CERTAIN AGRICULTURAL COMMODITIES Regulations Original Inspection Service § 868.44 New original... applicant may request a new original inspection on any previously inspected lot; except that a new original...

  15. The origin of the eukaryotic cell

    Science.gov (United States)

    Hartman, H.

    1984-01-01

    The endosymbiotic hypothesis for the origin of the eukaryotic cell has been applied to the origin of the mitochondria and chloroplasts. However as has been pointed out by Mereschowsky in 1905, it should also be applied to the nucleus as well. If the nucleus, mitochondria and chloroplasts are endosymbionts, then it is likely that the organism that did the engulfing was not a DNA-based organism. In fact, it is useful to postulate that this organism was a primitive RNA-based organism. This hypothesis would explain the preponderance of RNA viruses found in eukaryotic cells. The centriole and basal body do not have a double membrane or DNA. Like all MTOCs (microtubule organising centres), they have a structural or morphic RNA implicated in their formation. This would argue for their origin in the early RNA-based organism rather than in an endosymbiotic event involving bacteria. Finally, the eukaryotic cell uses RNA in ways quite unlike bacteria, thus pointing to a greater emphasis of RNA in both control and structure in the cell. The origin of the eukaryotic cell may tell us why it rather than its prokaryotic relative evolved into the metazoans who are reading this paper.

  16. The National Origins of Policy Ideas

    DEFF Research Database (Denmark)

    Campbell, John L.; Pedersen, Ove K.

    2014-01-01

    In this article John Campbell and Ove Pedersen argue that the way policy ideas are generated by knowledge regimes varies considerably across countries; and the effect on national politics is significant. The article is adapted from The National Origins of Policy Ideas: Knowledge Regimes...

  17. Origin of the Earth and planets

    International Nuclear Information System (INIS)

    Safronov, V.S.; Ruskol, E.L.

    1982-01-01

    The present state of the Schmidt hypothesis on planets formation by combining cold solid particles and bodies in the protoplanet dust cloud is briefly outlined in a popular form. The most debatable problems of the planet cosmogony: formation of and processes in a protoplanet cloud, results of analytical evaluations and numerical simulation of origin of the Earth and planets-giants are discussed [ru

  18. Theoretical origin of quark mass matrices

    International Nuclear Information System (INIS)

    Mohapatra, R.N.

    1987-01-01

    This paper presents the theoretical origin of specific quark mass matrices in the grand unified theories. The author discusses the first natural derivation of the Stech-type mass matrix in unified gauge theories. A solution to the strong CP-problem is provided

  19. The origin and mission of material religion

    NARCIS (Netherlands)

    Meyer, B.; Morgan, D.; Paine, C.; Plate, S.B.

    2010-01-01

    Beginning its sixth year of publication, Material Religion is an interdisciplinary journal that seeks to gather the best work from around the world engaged in materializing the study of religions. The editors welcome original scholarship on any religion and from any period in human history that

  20. Conflict Resolution between Mexican Origin Adolescent Siblings

    Science.gov (United States)

    Killoren, Sarah E.; Thayer, Shawna M.; Updegraff, Kimberly A.

    2008-01-01

    We investigated correlates of adolescents' sibling conflict resolution strategies in 246, two-parent Mexican origin families. Specifically, we examined links between siblings' conflict resolution strategies and sibling dyad characteristics, siblings' cultural orientations and values, and sibling relationship qualities. Data were gathered during…

  1. Quantum mechanical effects of topological origin

    Science.gov (United States)

    Duru, I. H.

    1993-01-01

    Following a brief review of the original Casimir and Aharonov-Bohm effects, some other effects of similar natures are mentioned. A Casimir interaction between AB fluxes is presented. Possible realizations of the Casimir effects for massive charged fields in solid state structures and a new AB effect for photons are suggested.

  2. The origin of the solar system

    International Nuclear Information System (INIS)

    Dormand, J.R.; Woolfson, M.M.

    1989-01-01

    This book describes in detail the capture theory of the origin of the solar system. Traces the history of solar system theories from pre-Christian Greece through the late 1920's. The authors examine the shortcomings of modern theories, and show how new knowledge supports the capture hypothesis

  3. Brazilian Vaccinia Viruses and Their Origins

    Centers for Disease Control (CDC) Podcasts

    Smallpox was eradicated more than 25 years ago, but live viruses used in vaccines may have survived to cause animal and human illness today. Dr. Inger Damon, Acting Branch Chief of the Poxvirus and Rabies Branch at CDC, discusses efforts to determine origins and spread of vaccinia viruses in Brazil.

  4. ORIGIN AND HISTORY OF PROGRAM BUDGETING.

    Science.gov (United States)

    NOVICK, DAVID

    THE ORIGIN AND HISTORICAL DEVELOPMENT OF PROGRAM BUDGETING, WHICH IS CURRENTLY APPLIED TO ALL THE EXECUTIVE OFFICES AND AGENCIES OF THE UNITED STATES GOVERNMENT, IS TRACED. IT WAS RECOGNIZED AND APPLIED AS EARLY AS 1924 BY INDUSTRY, UTILIZED AS PART OF THE WARTIME CONTROL SYSTEM IN 1942, AND IS USED TODAY BY THE DEPARTMENT OF DEFENSE. THIS IS A…

  5. Recognition in ants: social origin matters.

    Directory of Open Access Journals (Sweden)

    Joël Meunier

    Full Text Available The ability of group members to discriminate against foreigners is a keystone in the evolution of sociality. In social insects, colony social structure (number of queens is generally thought to influence abilities of resident workers to discriminate between nestmates and non-nestmates. However, whether social origin of introduced individuals has an effect on their acceptance in conspecific colonies remains poorly explored. Using egg-acceptance bioassays, we tested the influence of social origin of queen-laid eggs on their acceptance by foreign workers in the ant Formica selysi. We showed that workers from both single- and multiple-queen colonies discriminated against foreign eggs from single-queen colonies, whereas they surprisingly accepted foreign eggs from multiple-queen colonies. Chemical analyses then demonstrated that social origins of eggs and workers could be discriminated on the basis of their chemical profiles, a signal generally involved in nestmate discrimination. These findings provide the first evidence in social insects that social origins of eggs interfere with nestmate discrimination and are encoded by chemical signatures.

  6. ORIGINAL ARTICLES Huntington's disease: Genetic heterogeneity ...

    African Journals Online (AJOL)

    2008-03-01

    Mar 1, 2008 ... African origin.5 HD is considered rare among South African blacks, with an ... functions, syphilis, HIV and other tests in selected patients. We .... The discovery of a second genetic locus, resulting in HDL2,7 suggests the need ...

  7. Comet mission hopes to uncover Earth's origins

    CERN Multimedia

    Henderson, M

    2004-01-01

    "A European spacecraft that will hunt down a comet in search of clues to the origin of life on Earth will blast off tomorrow from the Kourou spaceport in French Guiana. The Rosetta probe will take 12 years to catch up with Churyumov-Gerasimenko before becoming the first spacecraft to make a soft, controlled landing on a comet's nucleus" (1 page).

  8. Origin, structure and evolution of galaxies

    International Nuclear Information System (INIS)

    Zhi, F.L.

    1988-01-01

    Recent developments of the origin, structure and evolution of galaxies have been reviewed. The contents of this book are: Inflationary Universe; Cosmic String; Active Galaxies; Intergalactic Medium; Waves in Disk Galaxies; Dark Matter; Gas Dynamics in Disk Galaxies; Equilibrium and Stability of Spiral Galaxies

  9. The origin of large scale cosmic structure

    International Nuclear Information System (INIS)

    Jones, B.J.T.; Palmer, P.L.

    1985-01-01

    The paper concerns the origin of large scale cosmic structure. The evolution of density perturbations, the nonlinear regime (Zel'dovich's solution and others), the Gott and Rees clustering hierarchy, the spectrum of condensations, and biassed galaxy formation, are all discussed. (UK)

  10. Animal evolution: stiff or squishy notochord origins?

    Science.gov (United States)

    Hejnol, Andreas; Lowe, Christopher J

    2014-12-01

    The notochord is considered an evolutionary novelty and one of the defining characters of chordates. A new study of an annelid challenges this view and proposes an earlier evolutionary origin in the most recent common ancestor of chordates and annelids. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. The origins of Technetium in the environment

    International Nuclear Information System (INIS)

    Scoppa, P.

    1986-01-01

    The origins of Technetium in the environment are briefly illustrated, taking into account its main sources represented by same plants of nuclear fuel cycle and by fallout fallowing nuclear explosion in atmosphere. An evaluation is also made of the TC-99 quantitees deriving from the production of nuclear power present in radioactive wastes before their final disposal

  12. Human Behaviour and the Origin of Man

    Science.gov (United States)

    Raleigh, M. J.; Washburn, S. L.

    1973-01-01

    The study of origin and evolution of man gives new perspective for understanding his behavior. Physical behaviors such as walking and throwing are results of biological evolution which has not kept pace with sociocultural evolution. Irrational decisions by man in social, cultural, and political fields are results of this brain activity. (PS)

  13. On the origin of hyperfast neutron stars

    NARCIS (Netherlands)

    Gvaramadze, V.V.; Gualandris, A.; Portegies Zwart, S.

    2007-01-01

    We propose an explanation for the origin of hyperfast neutron stars (e.g. PSR B1508+55, PSR B2224+65, RX J0822-4300) based on the hypothesis that they could be the remnants of a symmetric supernova explosion of a high-velocity massive star (or its helium core) which attained its peculiar velocity

  14. Extraembryonic origin of circulating endothelial cells.

    Directory of Open Access Journals (Sweden)

    Luc Pardanaud

    Full Text Available Circulating endothelial cells (CEC are contained in the bone marrow and peripheral blood of adult humans and participate to the revascularization of ischemic tissues. These cells represent attractive targets for cell or gene therapy aimed at improving ischemic revascularization or inhibition of tumor angiogenesis. The embryonic origin of CEC has not been addressed previously. Here we use quail-chick chimeras to study CEC origin and participation to the developing vasculature. CEC are traced with different markers, in particular the QH1 antibody recognizing only quail endothelial cells. Using yolk-sac chimeras, where quail embryos are grafted onto chick yolk sacs and vice-versa, we show that CEC are generated in the yolk sac. These cells are mobilized during wound healing, demonstrating their participation to angiogenic repair processes. Furthermore, we found that the allantois is also able to give rise to CEC in situ. In contrast to the yolk sac and allantois, the embryo proper does not produce CEC. Our results show that CEC exclusively originate from extra-embryonic territories made with splanchnopleural mesoderm and endoderm, while definitive hematopoietic stem cells and endothelial cells are of intra-embryonic origin.

  15. Extraembryonic origin of circulating endothelial cells.

    Science.gov (United States)

    Pardanaud, Luc; Eichmann, Anne

    2011-01-01

    Circulating endothelial cells (CEC) are contained in the bone marrow and peripheral blood of adult humans and participate to the revascularization of ischemic tissues. These cells represent attractive targets for cell or gene therapy aimed at improving ischemic revascularization or inhibition of tumor angiogenesis. The embryonic origin of CEC has not been addressed previously. Here we use quail-chick chimeras to study CEC origin and participation to the developing vasculature. CEC are traced with different markers, in particular the QH1 antibody recognizing only quail endothelial cells. Using yolk-sac chimeras, where quail embryos are grafted onto chick yolk sacs and vice-versa, we show that CEC are generated in the yolk sac. These cells are mobilized during wound healing, demonstrating their participation to angiogenic repair processes. Furthermore, we found that the allantois is also able to give rise to CEC in situ. In contrast to the yolk sac and allantois, the embryo proper does not produce CEC. Our results show that CEC exclusively originate from extra-embryonic territories made with splanchnopleural mesoderm and endoderm, while definitive hematopoietic stem cells and endothelial cells are of intra-embryonic origin.

  16. Fetal and infant origins of asthma

    NARCIS (Netherlands)

    L. Duijts (Liesbeth)

    2012-01-01

    textabstractPrevious studies have suggested that asthma, like other common diseases, has at least part of its origin early in life. Low birth weight has been shown to be associated with increased risks of asthma, chronic obstructive airway disease, and impaired lung function in adults, and increased

  17. Original Sin and T. E. Hulme's Aesthetics

    Science.gov (United States)

    Kishler, Thomas C.

    1976-01-01

    T. E. Hulme, a vigorous opponent of romanticism in art, poetry, and philosophy, insisted that the underlying flaw of the romantic view was its rejection of the dogma of Original Sin and the fall of man. His views are explored for the significant bearing they have on the development of aesthetic insight and indirectly on value and outlook.…

  18. The Basque Language: History and Origin1

    African Journals Online (AJOL)

    the widespread adoption by Hindi of Urdu words, ultimately of Persian origin, e.g. ...... Cf. Ge‟ez nigūś, Amharic nigūs „king, emperor‟, Hebrew nōgēś „taskmaster, .... http://journal.nostratic.ru/db/files/%2833%29jlr2010-3%2879-116%29.pdf.

  19. Tribal Colleges: The Original Extreme Makeover Experts

    Science.gov (United States)

    Powless, Donna

    2015-01-01

    In this article, the author states "our experience with education is a prime example in proving we are experts at problem-solving and are the originators of the extreme makeover." Educational institutions were introduced to the Native people in an outrageous manner--often as a mask for assimilating American Indians, routinely resulting…

  20. On the origin of rheumatoid arthritis

    DEFF Research Database (Denmark)

    Svendsen, Anders J; Kyvik, Kirsten O; Houen, Gunnar

    2013-01-01

    Rheumatoid arthritis (RA) is an autoimmune disease with a complex origin. Previous studies have reported heritability estimates on RA at about 60%. Only 16% of the genetic background of the disease has been disclosed so far. The purpose of the present investigation was to provide an optimized...

  1. The Colibactin Genotoxin Generates DNA Interstrand Cross-Links in Infected Cells

    Directory of Open Access Journals (Sweden)

    Nadège Bossuet-Greif

    2018-03-01

    Full Text Available Colibactins are hybrid polyketide-nonribosomal peptides produced by Escherichia coli, Klebsiella pneumoniae, and other Enterobacteriaceae harboring the pks genomic island. These genotoxic metabolites are produced by pks-encoded peptide-polyketide synthases as inactive prodrugs called precolibactins, which are then converted to colibactins by deacylation for DNA-damaging effects. Colibactins are bona fide virulence factors and are suspected of promoting colorectal carcinogenesis when produced by intestinal E. coli. Natural active colibactins have not been isolated, and how they induce DNA damage in the eukaryotic host cell is poorly characterized. Here, we show that DNA strands are cross-linked covalently when exposed to enterobacteria producing colibactins. DNA cross-linking is abrogated in a clbP mutant unable to deacetylate precolibactins or by adding the colibactin self-resistance protein ClbS, confirming the involvement of the mature forms of colibactins. A similar DNA-damaging mechanism is observed in cellulo, where interstrand cross-links are detected in the genomic DNA of cultured human cells exposed to colibactin-producing bacteria. The intoxicated cells exhibit replication stress, activation of ataxia-telangiectasia and Rad3-related kinase (ATR, and recruitment of the DNA cross-link repair Fanconi anemia protein D2 (FANCD2 protein. In contrast, inhibition of ATR or knockdown of FANCD2 reduces the survival of cells exposed to colibactin-producing bacteria. These findings demonstrate that DNA interstrand cross-linking is the critical mechanism of colibactin-induced DNA damage in infected cells.

  2. Original antigenic sin: A comprehensive review.

    Science.gov (United States)

    Vatti, Anup; Monsalve, Diana M; Pacheco, Yovana; Chang, Christopher; Anaya, Juan-Manuel; Gershwin, M Eric

    2017-09-01

    The concept of "original antigenic sin" was first proposed by Thomas Francis, Jr. in 1960. This phenomenon has the potential to rewrite what we understand about how the immune system responds to infections and its mechanistic implications on how vaccines should be designed. Antigenic sin has been demonstrated to occur in several infectious diseases in both animals and humans, including human influenza infection and dengue fever. The basis of "original antigenic sin" requires immunological memory, and our immune system ability to autocorrect. In the context of viral infections, it is expected that if we are exposed to a native strain of a pathogen, we should be able to mount a secondary immune response on subsequent exposure to the same pathogen. "Original antigenic sin" will not contradict this well-established immunological process, as long as the subsequent infectious antigen is identical to the original one. But "original antigenic sin" implies that when the epitope varies slightly, then the immune system relies on memory of the earlier infection, rather than mount another primary or secondary response to the new epitope which would allow faster and stronger responses. The result is that the immunological response may be inadequate against the new strain, because the immune system does not adapt and instead relies on its memory to mount a response. In the case of vaccines, if we only immunize to a single strain or epitope, and if that strain/epitope changes over time, then the immune system is unable to mount an accurate secondary response. In addition, depending of the first viral exposure the secondary immune response can result in an antibody-dependent enhancement of the disease or at the opposite, it could induce anergy. Both of them triggering loss of pathogen control and inducing aberrant clinical consequences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. In search of the origin of mass.

    Science.gov (United States)

    Shears, T G; Heinemann, B; Waters, D

    2006-12-15

    Particle physics explores the structure of matter by studying the behaviour of its most fundamental constituents. Despite the remarkable success of our theories, there remains much that is fundamental but unexplained. One of our most pressing questions concerns the origin of mass. Our favoured theoretical explanation for the existence of mass also predicts the existence of a particle that has never been seen-the Higgs boson. In this review, we survey our knowledge of the Higgs boson and explain why, if the theory is correct, we should expect to make our first observation of the elusive Higgs in the next few years, when a major new particle physics facility starts operating. This will be the most powerful particle accelerator in the world. Although searching for the Higgs boson will be challenging in this environment, we hope that our experimental results will allow us to finally understand the origin of mass and extend our knowledge of the Universe yet further.

  4. Common origin of visible and dark universe

    International Nuclear Information System (INIS)

    Gu Peihong; Sarkar, Utpal

    2010-01-01

    Dark matter, baryonic matter, and dark energy have different properties but contribute comparable energy density to the present Universe. We point out that they may have a common origin. As the dark energy has a scale far lower than all known scales in particle physics but very close to neutrino masses, while the excess matter over antimatter in the baryonic sector is probably related to the neutrino-mass generation, we unify the origin of the dark and visible universe in a variant of the seesaw model. In our model (i) the dark matter relic density is a dark matter asymmetry emerged simultaneously with the baryon asymmetry from leptogenesis; (ii) the dark energy is due to a pseudo-Nambu-Goldstone-Boson associated with the neutrino-mass generation.

  5. Original Good, Adaptation Bad”

    DEFF Research Database (Denmark)

    Jensen, Pia Majbritt

    reflect that respondents take a more positive stand on the original series, whereas the Anglophone adaptations are viewed more critically in an almost knee-jerk fashion, and I analyse the possible reasons why this may be. However, instead of only arguing that these stark differences in reception...... are caused by the originals’ superior quality insofar as story-telling, acting and aesthetics are concerned – as do the respondents – I investigate the reasons behind why an Anglophone audience such as my Sydney-based respondents may receive the Nordic originals more generously than the American and British......, I also point to a comparable study on the Danish and foreign reception of the Pan-European crime series Mord uden grænser/The Team, which had similar findings (Jacobsen and Jensen 2016)....

  6. Charles Darwin and the origin of life.

    Science.gov (United States)

    Peretó, Juli; Bada, Jeffrey L; Lazcano, Antonio

    2009-10-01

    When Charles Darwin published The Origin of Species 150 years ago he consciously avoided discussing the origin of life. However, analysis of some other texts written by Darwin, and of the correspondence he exchanged with friends and colleagues demonstrates that he took for granted the possibility of a natural emergence of the first life forms. As shown by notes from the pages he excised from his private notebooks, as early as 1837 Darwin was convinced that "the intimate relation of Life with laws of chemical combination, & the universality of latter render spontaneous generation not improbable". Like many of his contemporaries, Darwin rejected the idea that putrefaction of preexisting organic compounds could lead to the appearance of organisms. Although he favored the possibility that life could appear by natural processes from simple inorganic compounds, his reluctance to discuss the issue resulted from his recognition that at the time it was possible to undertake the experimental study of the emergence of life.

  7. [Herbal textual research on origins of Chonglou].

    Science.gov (United States)

    Jiang, Lu; Kang, Li-Ping; Liu, Da-Hui; Peng, Hua-Sheng; Xie, Jin; Chen, Min

    2017-09-01

    Based on the field investigation, this paper researched the germplasms and geoherbs habitat of Chonglou in ancient herbal books systematically. The results showed that, Chonglou in ancient herbal books sometimes referred to certain specific germplasm, while sometimes it referred to many species derived from genus Paris except Sect. Paris. The medicinal material Chonglou in Chinese Materia Medica Bencaotujing and Bencaomengquan was verified as P. polyphylla var. chinensis, which could be P. polyphylla in Xinxiubencao, and it should include P. polyphylla or P. polyphylla var. stenophylla in Bencaogangmu. However, it proved to be a variety of species from Paris that can used as Chonglou in Diannanbencao and Zhiwumingshitukao. Moreover, the origins of Chonglou were correspondingly more diverse, with its producing areas changed from North to South. Therefore, with the resources increasing endangered, the botanical origin of Chonglou should be further studied. Copyright© by the Chinese Pharmaceutical Association.

  8. The cosmological origin of time asymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Castagnino, Mario [Instituto de Astronomia y Fisica del Espacio, Casilla de Correos 67, Sucursal 28, 1428 Buenos Aires (Argentina); Lara, Luis [Departamento de Fisica, Universidad Nacional de Rosario, Av. Pellegrini 250, 2000 Rosario (Argentina); Lombardi, Olimpia [CONICET - Universidad de Buenos Aires, Puan 470, 1406 Buenos Aires (Argentina)

    2003-01-21

    In this paper, we address the problem of the arrow of time from a cosmological point of view, rejecting the traditional entropic approach that defines the future direction of time as the direction of the entropy increase: from our perspective, the arrow of time has a global origin and it is an intrinsic, geometrical feature of spacetime. Time orientability and the existence of a cosmic time are necessary conditions for defining an arrow of time, which is manifested globally as the time asymmetry of the universe as a whole, and locally as a time-asymmetric energy flux. We also consider arrows of time of different origins (quantum, electromagnetic, thermodynamic, etc) showing that they can be non-conventionally defined only if the geometrical arrow is previously defined.

  9. Origins fourteen billion years of cosmic evolution

    CERN Document Server

    Tyson, Neil deGrasse

    2004-01-01

    Origins explores cosmic science's stunning new insights into the formation and evolution of our universe--of the cosmos, of galaxies and galaxy clusters, of stars within galaxies, of planets that orbit those stars, and of different forms of life that take us back to the first three seconds and forward through three billion years of life on Earth to today's search for life on other planets. Drawing on the current cross-pollination of geology, biology and astrophysics, Origins explains the thrilling daily breakthroughs in our knowledge of the universe from dark energy to life on Mars to the mysteries of space and time. Distilling complex science in clear and lively prose, co-authors Neil deGrasse Tyson and Donald Goldsmith conduct a galvanising tour of the cosmos revealing what the universe has been up to while turning part of itself into us.

  10. The Recruitment Theory of Language Origins

    Science.gov (United States)

    Steels, Luc

    Tremendous progress has been made recently on the fascinating question of the origins and evolution of language (see e.g. (55), (7), (9), (31)). There is no widely accepted complete theory yet, but several proposals are on the table and observations and experiments are proceeding. This chapter focuses on the recruitment theory of language origins which we have been exploring for almost ten years now. This theory argues that language users recruit and try out different strategies for solving the task of communication and retain those that maximise communicative success and cognitive economy. Each strategy requires specific cognitive neural mechanisms, which in themselves serve a wide range of purposes and therefore may have evolved or could be learned independently of language.

  11. Earth's earliest biosphere: Its origin and evolution

    International Nuclear Information System (INIS)

    Schopf, J.W.

    1983-01-01

    Some of the subjects discussed are related to the early biogeologic history, the nature of the earth prior to the oldest known rock record, the early earth and the Archean rock record, the prebiotic organic syntheses and the origin of life, Precambrian organic geochemistry, the biochemical evolution of anaerobic energy conversion, the isotopic inferences of ancient biochemistries, Archean stromatolites providing evidence of the earth's earliest benthos, Archean microfossils, the geologic evolution of the Archean-Early Proterozoic earth, and the environmental evolution of the Archean-Early Proterozoic earth. Other topics examined are concerned with geochemical evidence bearing on the origin of aerobiosis, biological and biochemical effects of the development of an aerobic environment, Early Proterozoic microfossils, the evolution of earth's earliest ecosystems, and geographic and geologic data for processed rock samples. Attention is given to a processing procedure for abiotic samples and calculation of model atmospheric compositions, and procedures of organic geochemical analysis

  12. The Really Real, Authentic, Original Shakespeare

    Directory of Open Access Journals (Sweden)

    Kostihova Marcela

    2016-06-01

    Full Text Available This essay considers the question of how original/new interpretations help redefine (or reify the original/old perception of Shakespeare and the work its cultural capital performs, demonstrating the inherent impossibility of reconciling an “original” Shakespeare with contemporary performances of his plays through a reading of Twelfth Night, and address some of the ideological implications of trying to conflate the two. It then takes a detour into contemporary marketing and consumer-psychology literature to explore the crucial roles which the concepts of “authenticity” and “originality” have come to play in contemporary consumer culture, circling back to Shakespeare, to ruminate on the implications of the use of his cultural capital as an ultimate positional good in the 21st century.

  13. Origin of the diffuse background gamma radiation

    International Nuclear Information System (INIS)

    Stecker, F.W.; Puget, J.L.

    1974-05-01

    Recent observations have now provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV. There is some evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation were observed which provide evidence for its origin in nuclear processes in the early stages of the big-band cosmology and tie in these processes with galaxy formation theory. A crucial test of the theory may lie in future observations of the background radiation in the 100 MeV to 100 GeV energy range which may be made with large orbiting spark-chamber satellite detectors. A discussion of the theoretical interpretations of present data, their connection with baryon symmetric cosmology and galaxy formation theory, and the need for future observations are given. (U.S.)

  14. Origin and pathogenesis of antiphospholipid antibodies

    Directory of Open Access Journals (Sweden)

    C.M. Celli

    1998-06-01

    Full Text Available Antiphospholipid antibodies (aPL are a heterogeneous group of antibodies that are detected in the serum of patients with a variety of conditions, including autoimmune (systemic lupus erythematosus, infectious (syphilis, AIDS and lymphoproliferative disorders (paraproteinemia, myeloma, lymphocytic leukemias. Thrombosis, thrombocytopenia, recurrent fetal loss and other clinical complications are currently associated with a subgroup of aPL designating the antiphospholipid syndrome. In contrast, aPL from patients with infectious disorders are not associated with any clinical manifestation. These findings led to increased interest in the origin and pathogenesis of aPL. Here we present the clinical features of the antiphospholipid syndrome and review the origin of aPL, the characteristics of experimentally induced aPL and their historical background. Within this context, we discuss the most probable pathogenic mechanisms induced by these antibodies.

  15. The Eastern Origin of English Words

    Directory of Open Access Journals (Sweden)

    Ömer Şekerci

    2007-04-01

    Full Text Available Etymology is a branch of linguistics describing the origin of words, their changeand development. To-day the far reaching advances in linguistics and in ELT and EFLoblige us, teachers of English to know well not only the language itself but about thelanguage as well. So are they for the English vocabulary. This paper explains thereasons for the percentage of borrowings in the English language. Explanations for thisshould be sought in the eventful history of England. If to summarize the origin of theEnglish vocabulary, it can be roughly called Anglo-Saxon, Norman, Scandinavian andFrench. However, the borrowings are not confined only to these languages. There areborrowings from Arabic, Turkish, Indian and many others. Some of the borrowingshave been fully adapted to the phonetic system of the English language, while otherslook and sound as loan words. The English language can be regarded as the mosthospitable language in the world.

  16. Geographical origin: meaningful reference or marketing tool?

    DEFF Research Database (Denmark)

    Hedegaard, Liselotte

    2015-01-01

    dimensions of local culture. The French label served as inspiration for the European PDO/PGI-labels, but even if these labels are known in Denmark only five products are PDO-branded The data-collection in Denmark indicated little trust in increased sales through PDO-labelling. This was contrary to data...... of production can be positioned on a map, but there is no precise standard for the rootedness of the product in this place. Origin means to be from a place in the sense that natural factors, cultural practices and historical links contribute to the understanding of the link between food and place...... origin was the result of a crisis in French wine-production in the early 20th century. Labelling was intended to protect the reputation of a product in terms of quality and taste by referring to parcels of land where specific traditions are maintained and the resulting products embedded in collective...

  17. The origin of Wolf-Rayet stars

    International Nuclear Information System (INIS)

    Doom, C.

    1987-01-01

    The paper reviews the origin of Wolf-Rayet (WR) stars, with emphasis on the so-called Population I WR stars which are associated with the young and luminous stellar population. A description is given of the observational characteristics i.e. classification, luminosities composition, etc. of WR stars. The origin and evolution of WR stars is described, including the single, binary, subtypes and ratio WR/O. The interaction of the WR stars with their environment is discussed with respect to the energy deposition and composition anomalies. A brief account of the discovery of WR stars in other galaxies is given. Finally, some of the main issues in the research into the structure and evolution of WR stars are outlined. (U.K.)

  18. Cosmic Origins Program Annual Technology Report

    Science.gov (United States)

    Pham, Bruce Thai; Neff, Susan Gale

    2015-01-01

    What is the Cosmic Origins (COR) Program? From ancient times, humans have looked up at the night sky and wondered: Are we alone? How did the universe come to be? How does the universe work? COR focuses on the second question. Scientists investigating this broad theme seek to understand the origin and evolution of the universe from the Big Bang to the present day, determining how the expanding universe grew into a grand cosmic web of dark matter enmeshed with galaxies and pristine gas, forming, merging, and evolving over time. COR also seeks to understand how stars and planets form from clouds in these galaxies to create the heavy elements that are essential to life starting with the first generation of stars to seed the universe, and continuing through the birth and eventual death of all subsequent generations of stars. The COR Programs purview includes the majority of the field known as astronomy, from antiquity to the present.

  19. The origin of the planetesimal theory.

    Science.gov (United States)

    Brush, S G

    1977-04-01

    T. C. Chamberlin suggested in 1897, on the basis of geological and climatological arguments, that the planets were formed by accretion of cold solid partices. With F. R. Moulton he developed convincing arguments against the Laplace nebular hypothesis and published a comprehensive 'planetesimal theory' of the origin of the solar system in 1905. The Chamberlin-Moulton theory has current as well as historical interest.

  20. Agricultural origins on the Anatolian plateau

    OpenAIRE

    Baird, D.; Fairbairn, A.; Jenkins, Emma L.; Martin, L.; Middleton, C.; Pearson, J.; Asouti, E.; Edwards, Y.; Kabukcu, C.; Mustafaoğlu, G.; Russell, N.; Bar-Yosef, O.; Jacobsen, G.; Wu, X.

    2018-01-01

    This paper explores explanations for, and consequences of, the early appearance of food production outside the Fertile Crescent of Southwest Asia, where it had originated in the 10th/9th millennium cal BC. We present evidence that cultivation appeared in Central Anatolia through adoption by indigenous foragers in the mid 9th millennium cal BC, but also demonstrate that uptake was not uniform, and that some communities chose to actively disregard cultivation. Adoption of cultivation seems to h...

  1. On the origin of constrained superfields

    Energy Technology Data Exchange (ETDEWEB)

    Dall’Agata, G. [Dipartimento di Fisica “Galileo Galilei”, Università di Padova,Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova,Via Marzolo 8, 35131 Padova (Italy); Dudas, E. [Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay,F-91128 Palaiseau (France); Farakos, F. [Dipartimento di Fisica “Galileo Galilei”, Università di Padova,Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova,Via Marzolo 8, 35131 Padova (Italy)

    2016-05-06

    In this work we analyze constrained superfields in supersymmetry and supergravity. We propose a constraint that, in combination with the constrained goldstino multiplet, consistently removes any selected component from a generic superfield. We also describe its origin, providing the operators whose equations of motion lead to the decoupling of such components. We illustrate our proposal by means of various examples and show how known constraints can be reproduced by our method.

  2. Origin and domestication of native Amazonian crops

    OpenAIRE

    Clément, R. Charles; De Cristo-Araujo, Michelly; Coppens D'Eeckenbrugge, Géo; Alves Pereira, Allessandro; Picanço-Rodrigues, Doriane

    2010-01-01

    Molecular analyses are providing new elements to decipher the origin, domestication and dispersal of native Amazonian crops in an expanding archaeological context. Solid molecular data are available for manioc (Manihot esculenta), cacao (Theobroma cacao), pineapple (Ananas comosus), peach palm (Bactris gasipaes) and guaraná (Paullinia cupana), while hot peppers (Capsicum spp.), inga (Inga edulis), Brazil nut (Bertholletia excelsa) and cupuassu (Theobroma grandiflorum) are being studied. Emerg...

  3. The genetic origins of the Andaman Islanders

    DEFF Research Database (Denmark)

    Endicott, Phillip; Gilbert, M Thomas P; Stringer, Chris

    2002-01-01

    Mitochondrial sequences were retrieved from museum specimens of the enigmatic Andaman Islanders to analyze their evolutionary history. D-loop and protein-coding data reveal that phenotypic similarities with African pygmoid groups are convergent. Genetic and epigenetic data are interpreted as favo...... of humans through Asia. The results demonstrate that Victorian anthropological collections can be used to study extinct, or seriously admixed populations, to provide new data about early human origins....

  4. Depression and dementia of cerebrovascular origin

    Directory of Open Access Journals (Sweden)

    Marmorato Paulo Germano

    2002-01-01

    Full Text Available We report the case of a patient who presented various psychiatric syndromes at the time of evaluation - partial complex epileptic seizures, personality change, and severe depression, which eventually progressed to dementia - resulting from multiple cerebral infarctions of probable neuro-angiopathic origin, of unknown etiology. Aspects related to depression following cerebrovascular accidents, as well as how cerebrovascular accidents can result in different disorders depending on the variables, are discussed based on the data from current literature.

  5. The Origins of dEs

    Science.gov (United States)

    Skillman, Evan D.

    With the new discoveries that some dEs are rotationally supported and that dIs may show a large variety in star formation histories, the perceived relationships between these two families of galaxies are changing. There are at least three viable channels for the origin of dwarf elliptical galaxies with strong observational evidence that support their reality. I will discuss the observational evidence for each of these channels and the likely physical processes which determine each channel.

  6. The pion mass: Looking for its origins

    International Nuclear Information System (INIS)

    Peccei, R.D.

    1985-10-01

    After explaining why pions are special excitations in QCD, I discuss how the pion mass reflects directly the dynamical scale of the strong interactions (Λsub(QCD)) and the scale of breaking of the weak interactions (Λsub(F)). To actually calculate the pion mass, however, requires understanding the origin of the quark masses and so I compare and contrast approaches to this latter problem, based on composite models and on superstrings. (orig.)

  7. Mirror neurons: From origin to function

    OpenAIRE

    Cook, R; Bird, G; Catmur, C; Press, C; Heyes, C

    2014-01-01

    This article argues that mirror neurons originate in sensorimotor associative learning and therefore a new approach is needed to investigate their functions. Mirror neurons were discovered about 20 years ago in the monkey brain, and there is now evidence that they are also present in the human brain. The intriguing feature of many mirror neurons is that they fire not only when the animal is performing an action, such as grasping an object using a power grip, but also when the animal passively...

  8. Life Origination Hydrate Hypothesis (LOH-Hypothesis

    Directory of Open Access Journals (Sweden)

    Victor Ostrovskii

    2012-01-01

    Full Text Available The paper develops the Life Origination Hydrate Hypothesis (LOH-hypothesis, according to which living-matter simplest elements (LMSEs, which are N-bases, riboses, nucleosides, nucleotides, DNA- and RNA-like molecules, amino-acids, and proto-cells repeatedly originated on the basis of thermodynamically controlled, natural, and inevitable processes governed by universal physical and chemical laws from CH4, niters, and phosphates under the Earth's surface or seabed within the crystal cavities of the honeycomb methane-hydrate structure at low temperatures; the chemical processes passed slowly through all successive chemical steps in the direction that is determined by a gradual decrease in the Gibbs free energy of reacting systems. The hypothesis formulation method is based on the thermodynamic directedness of natural movement and consists ofan attempt to mentally backtrack on the progression of nature and thus reveal principal milestones alongits route. The changes in Gibbs free energy are estimated for different steps of the living-matter origination process; special attention is paid to the processes of proto-cell formation. Just the occurrence of the gas-hydrate periodic honeycomb matrix filled with LMSEs almost completely in its final state accounts for size limitation in the DNA functional groups and the nonrandom location of N-bases in the DNA chains. The slowness of the low-temperature chemical transformations and their “thermodynamic front” guide the gross process of living matter origination and its successive steps. It is shown that the hypothesis is thermodynamically justified and testable and that many observed natural phenomena count in its favor.

  9. Brazilian Vaccinia Viruses and Their Origins

    Centers for Disease Control (CDC) Podcasts

    2007-07-30

    Smallpox was eradicated more than 25 years ago, but live viruses used in vaccines may have survived to cause animal and human illness today. Dr. Inger Damon, Acting Branch Chief of the Poxvirus and Rabies Branch at CDC, discusses efforts to determine origins and spread of vaccinia viruses in Brazil.  Created: 7/30/2007 by Emerging Infectious Diseases.   Date Released: 7/30/2007.

  10. The original colours of fossil beetles.

    Science.gov (United States)

    McNamara, Maria E; Briggs, Derek E G; Orr, Patrick J; Noh, Heeso; Cao, Hui

    2012-03-22

    Structural colours, the most intense, reflective and pure colours in nature, are generated when light is scattered by complex nanostructures. Metallic structural colours are widespread among modern insects and can be preserved in their fossil counterparts, but it is unclear whether the colours have been altered during fossilization, and whether the absence of colours is always real. To resolve these issues, we investigated fossil beetles from five Cenozoic biotas. Metallic colours in these specimens are generated by an epicuticular multi-layer reflector; the fidelity of its preservation correlates with that of other key cuticular ultrastructures. Where these other ultrastructures are well preserved in non-metallic fossil specimens, we can infer that the original cuticle lacked a multi-layer reflector; its absence in the fossil is not a preservational artefact. Reconstructions of the original colours of the fossils based on the structure of the multi-layer reflector show that the preserved colours are offset systematically to longer wavelengths; this probably reflects alteration of the refractive index of the epicuticle during fossilization. These findings will allow the former presence, and original hue, of metallic structural colours to be identified in diverse fossil insects, thus providing critical evidence of the evolution of structural colour in this group.

  11. Origin and Domestication of Native Amazonian Crops

    Directory of Open Access Journals (Sweden)

    Doriane Picanço-Rodrigues

    2010-01-01

    Full Text Available Molecular analyses are providing new elements to decipher the origin, domestication and dispersal of native Amazonian crops in an expanding archaeological context. Solid molecular data are available for manioc (Manihot esculenta, cacao (Theobroma cacao, pineapple (Ananas comosus, peach palm (Bactris gasipaes and guaraná (Paullinia cupana, while hot peppers (Capsicum spp., inga (Inga edulis, Brazil nut (Bertholletia excelsa and cupuassu (Theobroma grandiflorum are being studied. Emergent patterns include the relationships among domestication, antiquity (terminal Pleistocene to early Holocene, origin in the periphery, ample pre-Columbian dispersal and clear phylogeographic population structure for manioc, pineapple, peach palm and, perhaps, Capsicum peppers. Cacao represents the special case of an Amazonian species possibly brought into domestication in Mesoamerica, but close scrutiny of molecular data suggests that it may also have some incipiently domesticated populations in Amazonia. Another pattern includes the relationships among species with incipiently domesticated populations or very recently domesticated populations, rapid pre- or post-conquest dispersal and lack of phylogeographic population structure, e.g., Brazil nut, cupuassu and guaraná. These patterns contrast the peripheral origin of most species with domesticated populations with the subsequent concentration of their genetic resources in the center of the basin, along the major white water rivers where high pre-conquest population densities developed. Additional molecular genetic analyses on these and other species will allow better examination of these processes and will enable us to relate them to other historical ecological patterns in Amazonia.

  12. ORIGIN OF DUST AROUND V1309 SCO

    International Nuclear Information System (INIS)

    Zhu, Chunhua; Lü, Guoliang; Wang, Zhaojun

    2013-01-01

    The origin of dust grains in the interstellar medium is still an unanswered problem. Nicholls et al. found the presence of a significant amount of dust around V1309 Sco, which may originate from the merger of a contact binary. We investigate the origin of dust around V1309 Sco and suggest that these dust grains are produced in the binary-merger ejecta. By means of the AGBDUST code, we estimate that ∼5.2 × 10 –4 M ☉ dust grains are produced with a radii of ∼10 –5 cm. These dust grains are mainly composed of silicate and iron grains. Because the mass of the binary merger ejecta is very small, the contribution of dust produced by binary merger ejecta to the overall dust production in the interstellar medium is negligible. However, it is important to note that the discovery of a significant amount of dust around V1309 Sco offers a direct support for the idea that common-envelope ejecta provides an ideal environment for dust formation and growth. Therefore, we confirm that common envelope ejecta can be important source of cosmic dust

  13. An earlier origin for the Acheulian.

    Science.gov (United States)

    Lepre, Christopher J; Roche, Hélène; Kent, Dennis V; Harmand, Sonia; Quinn, Rhonda L; Brugal, Jean-Philippe; Texier, Pierre-Jean; Lenoble, Arnaud; Feibel, Craig S

    2011-08-31

    The Acheulian is one of the first defined prehistoric techno-complexes and is characterized by shaped bifacial stone tools. It probably originated in Africa, spreading to Europe and Asia perhaps as early as ∼1 million years (Myr) ago. The origin of the Acheulian is thought to have closely coincided with major changes in human brain evolution, allowing for further technological developments. Nonetheless, the emergence of the Acheulian remains unclear because well-dated sites older than 1.4 Myr ago are scarce. Here we report on the lithic assemblage and geological context for the Kokiselei 4 archaeological site from the Nachukui formation (West Turkana, Kenya) that bears characteristic early Acheulian tools and pushes the first appearance datum for this stone-age technology back to 1.76 Myr ago. Moreover, co-occurrence of Oldowan and Acheulian artefacts at the Kokiselei site complex indicates that the two technologies are not mutually exclusive time-successive components of an evolving cultural lineage, and suggests that the Acheulian was either imported from another location yet to be identified or originated from Oldowan hominins at this vicinity. In either case, the Acheulian did not accompany the first human dispersal from Africa despite being available at the time. This may indicate that multiple groups of hominins distinguished by separate stone-tool-making behaviours and dispersal strategies coexisted in Africa at 1.76 Myr ago.

  14. Evolutionary origins and diversification of proteobacterial mutualists.

    Science.gov (United States)

    Sachs, Joel L; Skophammer, Ryan G; Bansal, Nidhanjali; Stajich, Jason E

    2014-01-22

    Mutualistic bacteria infect most eukaryotic species in nearly every biome. Nonetheless, two dilemmas remain unresolved about bacterial-eukaryote mutualisms: how do mutualist phenotypes originate in bacterial lineages and to what degree do mutualists traits drive or hinder bacterial diversification? Here, we reconstructed the phylogeny of the hyperdiverse phylum Proteobacteria to investigate the origins and evolutionary diversification of mutualistic bacterial phenotypes. Our ancestral state reconstructions (ASRs) inferred a range of 34-39 independent origins of mutualist phenotypes in Proteobacteria, revealing the surprising frequency with which host-beneficial traits have evolved in this phylum. We found proteobacterial mutualists to be more often derived from parasitic than from free-living ancestors, consistent with the untested paradigm that bacterial mutualists most often evolve from pathogens. Strikingly, we inferred that mutualists exhibit a negative net diversification rate (speciation minus extinction), which suggests that mutualism evolves primarily via transitions from other states rather than diversification within mutualist taxa. Moreover, our ASRs infer that proteobacterial mutualist lineages exhibit a paucity of reversals to parasitism or to free-living status. This evolutionary conservatism of mutualism is contrary to long-standing theory, which predicts that selection should often favour mutants in microbial mutualist populations that exploit or abandon more slowly evolving eukaryotic hosts.

  15. Origin of irradiations by ionizing radiations

    International Nuclear Information System (INIS)

    Metivier, H.

    1998-01-01

    Irradiations by ionizing radiations proceed from two main sources: the natural radiations from the environment and the sources of 'human' origin, i.e. linked with modern technology. In most countries the irradiation by natural sources remains the most important. The irradiations for medical purposes comes in second position and depends on the degree of technological evolution of the country, and in the last position are the irradiations linked with nuclear industry. The inventory of these irradiations is regularly updated by the Scientific Committee of the United Nations for the study of ionizing radiation effects (UNSCEAR). In France the mean individual irradiation due to natural radioactivity is of 2 mSv per year of efficient dose and can vary with a factor 3 from one region to the other. Irradiation of medical diagnosis origin is of about 1 mSv per year. This paper presents successively: the natural irradiation sources (cosmic radiation, cosmic rays and cosmogenic radionuclides, the Earth's radiations, primary radionuclides and radon), the natural sources modified by the technology (extraction industries, fossil fuels and phosphated ores, aerial transports and space activities, consumer products), the irradiation sources of technological origin (nuclear weapons, electric power production, major accidents, occupational irradiations), and the medical irradiations (diagnosis techniques, radiology, nuclear medicine and therapeutic uses). (J.S.)

  16. On the origin of Indonesian cattle.

    Directory of Open Access Journals (Sweden)

    Kusdiantoro Mohamad

    Full Text Available BACKGROUND: Two bovine species contribute to the Indonesian livestock, zebu (Bos indicus and banteng (Bos javanicus, respectively. Although male hybrid offspring of these species is not fertile, Indonesian cattle breeds are supposed to be of mixed species origin. However, this has not been documented and is so far only supported by preliminary molecular analysis. METHODS AND FINDINGS: Analysis of mitochondrial, Y-chromosomal and microsatellite DNA showed a banteng introgression of 10-16% in Indonesian zebu breeds. East-Javanese Madura and Galekan cattle have higher levels of autosomal banteng introgression (20-30% and combine a zebu paternal lineage with a predominant (Madura or even complete (Galekan maternal banteng origin. Two Madura bulls carried taurine Y-chromosomal haplotypes, presumably of French Limousin origin. In contrast, we did not find evidence for zebu introgression in five populations of the Bali cattle, a domestic form of the banteng. CONCLUSIONS: Because of their unique species composition Indonesian cattle represent a valuable genetic resource, which potentially may also be exploited in other tropical regions.

  17. Comets and the origin of life

    Energy Technology Data Exchange (ETDEWEB)

    Delsemme, A H

    1981-01-01

    Current understandings of the nature and evolution of the universe and of the earth are summarized as a background to the discussion of the origin of life on earth as the result of the transport of the necessary materials to earth by comets. Evidence for the origin of the universe in the Big Bang supplied by observations of the expansion of the universe and the cosmic microwave background is discussed, and the condensation of primordial matter into galaxies and stars and the chemical processes in stars converting primordial hydrogen and helium into heavy elements as the stars evolve giving rise to an interstellar medium are considered. Attention is then given to the birth of the solar system from the contraction of a dark interstellar cloud containing gas, dust and interstellar molecules, and in particular to the origin of the terrestrial planets and the cometary contributions to the terrestrial crust, oceans and atmosphere. Finally, the chronology of the universe from the Big Bang to the present and that of the earth from its formation to the present are reviewed.

  18. THE ORIGINS AND NATURE OF MONEY

    Directory of Open Access Journals (Sweden)

    Mihaela IAVORSCHI

    2014-06-01

    Full Text Available The importance of money and the role they hold in the economy can be seen as the keystone of economic life. For a better understanding of the essence of the monetary phenomena it is especially important to turn to history and see how money was born. By turning to their origins, we discover the real fundaments of monetary issues. Only after such a systematic analysis we will be able to suggest the appropriate solutions for the current monetary issues. Therefore, in this study I will research the origin of money and their functionality on the market.The aim of this paper is to analyse the origin of money as a social institution. The appearance and use of money has prehistoric roots. People have turned to the usage of money out of need to facilitate trade. During thousands of years money has known different forms going from money as merchandise, to coins and later to paper money and electronic currency. In this study I have analysed the role of natural money, as well as their production and functionality on the market. The main questionto be answered is whether the production and functionality of paper money nowadays is the consequence of the free market, having the Austrian’s School liberal perspective as a starting point. This methodological approach demonstrates that money is and will remain a social institution and the implication of the authorities in the currency issuing, even from ancient times, has caused distortions in the economic activity.

  19. The origin of the RS CVn binaries

    International Nuclear Information System (INIS)

    Biermann, P.

    1976-01-01

    Six possible origins for the RS CVn binaries are considered based on the following possibilities. RS CVn binaries might now be either pre-main-sequence or post-main-sequence. A pre-main-sequence binary might not always have been a binary but might have resulted from fission of a rapidly rotating single pre-main-sequence star. The main-sequence counterparts might be either single stars or binaries. To decide which of the six origins is possible, the following observed data for the RS CVn binaries are considered: total mass, total angular momentum, lack of observed connection with regions of star formation, large space density, kinematical age, and the visual companion of WW Dra. In addition lifetimes and space densities of single stars and other types of binaries are considered. The only origin possible is that the RS CVn binaries are in a thermal phase following fission of a main-sequence single star. In this explanation the single star had a rapidly rotating core which became unstable due to the core contraction which made it begin to evolve off the main sequence. The present Be stars might be examples of such parent single stars. (Auth.)

  20. 40 CFR 52.1960 - Original Identification of plan section.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Original Identification of plan section... Original Identification of plan section. (a) This section identifies the original “State of Oklahoma Air... § 856.1(C) of the Oklahoma statutes to mean “original equipment manufacturer (OEM) or equivalent”. (40...

  1. 32 CFR 2001.11 - Original classification authority.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Original classification authority. 2001.11... Classification § 2001.11 Original classification authority. (a) General. Agencies shall establish a training program for original classifiers in accordance with subpart G of this part. (b) Requests for original...

  2. 7 CFR 800.115 - Who may request original services.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Who may request original services. 800.115 Section 800... Original Services § 800.115 Who may request original services. (a) General. Any interested person may request original inspection and weighing services. The kinds of inspection and weighing services are...

  3. 29 CFR 70.6 - Disclosure of originals.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Disclosure of originals. 70.6 Section 70.6 Labor Office of... of originals. (a) No original record or file in the custody of the Department of Labor, or of any... or the Inspector General. (b) The individual authorizing the release of the original record or file...

  4. 46 CFR 67.209 - No original instrument requirement.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false No original instrument requirement. 67.209 Section 67... original instrument requirement. A copy of the original signed and acknowledged instrument must be presented. The original instrument itself may be presented but is not required. The copy may be delivered to...

  5. 40 CFR 52.1190 - Original Identification of plan section.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Original Identification of plan section... Original Identification of plan section. (a) This section identifies the original “Air Implementation Plan... Stipulation for Entry of Consent Order and Final Order, No. 8-1982. The original Consent Order No. 8-1982 was...

  6. 40 CFR 52.2635 - Original identification of plan section.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Original identification of plan section... Original identification of plan section. (a) This section identifies the original “Air Implementation Plan... implementation plan (SIP) for Sheridan, Wyoming. In addition to the original August 28 submittal, eight...

  7. 40 CFR 52.2087 - Original identification of plan section.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Original identification of plan section... Original identification of plan section. (a) This section identifies the original “Air Implementation Plan.... (B) Original consent agreement between the Rhode Island Department of Environmental Management and...

  8. 31 CFR 248.6 - Recovery of original check.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Recovery of original check. 248.6... § 248.6 Recovery of original check. (a) If the claimant recovers an original check after he has... or agency concerned regarding the negotiability of such original check. (b) In the event the...

  9. 7 CFR 800.116 - How to request original services.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false How to request original services. 800.116 Section 800... Original Services § 800.116 How to request original services. (a) General. Except as otherwise provided for in § 800.117, requests for original services shall be filed with an agency or field office authorized...

  10. 40 CFR 52.2386 - Original identification of plan section.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Original identification of plan section... Original identification of plan section. (a) This section identifies the original “Air Implementation Plan... from the original approval of Regulation 5-231(3)(b) into the Vermont SIP identified at subparagraph (c...

  11. 40 CFR 52.2134 - Original identification of plan section.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Original identification of plan section... Original identification of plan section. (a) This section identifies the original “South Carolina Air... Charleston; for these two sources, the plan's original emission limits continue to apply.) (10) Permit...

  12. 40 CFR 52.1837 - Original identification of plan section.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Original identification of plan section... Original identification of plan section. (a) This section identifies the original “Air Implementation Plan...) Explanation of why sources could not comply by the original attainment date submitted April 23, 1975, by the...

  13. 15 CFR 762.4 - Original records required.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Original records required. 762.4... § 762.4 Original records required. The regulated person must maintain the original records in the form....5 of this part relating to reproduction of records. If the original record does not meet the...

  14. Possible galactic origin of. gamma. -ray bursts

    Energy Technology Data Exchange (ETDEWEB)

    Manchanda, R K; Ramsden, D [Southampton Univ. (UK). Dept. of Physics

    1977-03-31

    It is stated that extragalactic models for the origin of non-solar ..gamma..-ray bursts include supernova bursts in remote galaxies, and the collapse of the cores of active stars, whilst galactic models are based on flare stars, thermonuclear explosions in neutron stars and the sudden accretion of cometary gas on to neutron stars. The acceptability of any of these models may be tested by the observed size spectrum of the ..gamma..-ray bursts. The extragalactic models predict a power law spectrum with number index -1.5, whilst for the galactic models the number index will be -1. Experimental data on ..gamma..-ray bursts is, however, still meagre, and so far only 44 confirmed events have been recorded by satellite-borne instruments. The number spectrum of the observed ..gamma..-ray bursts indicates that the observed distribution for events with an energy < 10/sup -4/ erg/cm/sup 2/ is flat; this makes the choice of any model completely arbitrary. An analysis of the observed ..gamma..-ray events is here presented that suggests very interesting possibilities for their origin. There appears to be a preferred mean energy for ..gamma..-ray bursts; some 90% of the recorded events show a mean energy between 5 x 10/sup -5/ and 5 x 10/sup -4/ erg/cm/sup 2/, contrary to the predicted characteristics of the number spectrum of various models. A remarkable similarity is found between the distribution of ..gamma..-ray bursts and that of supernova remnants, suggesting a genetic relationship between the two and the galactic origin of the ..gamma..-ray bursts, and the burst source could be identified with completely run down neutron stars, formed during supernova explosions.

  15. Origins Space Telescope: Cosmology and Reionization

    Science.gov (United States)

    Vieira, Joaquin Daniel; Origins Space Telescope

    2018-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its imagers and spectrographs will enable a variety of surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu.A core science goal of the OST mission is to study the the cosmological history of star, galaxy, and structure formation into the epoch of reionization (EoR). OST will probe the birth of galaxies through warm molecular hydrogen emission during the cosmic dark ages. Utilizing the unique power of the infrared fine-structure emission lines, OST will trace the rise of metals from the first galaxies until today. It will quantify the dust enrichment history of the Universe, uncover its composition and physical conditions, reveal the first cosmic sources of dust, and probe the properties of the earliest star formation. OST will provide a detailed astrophysical probe into the condition of the intergalactic medium at z > 6 and the galaxies which dominate the epoch of reionization.

  16. The origin and evolution of Homo sapiens

    OpenAIRE

    Stringer, Chris

    2016-01-01

    If we restrict the use of Homo sapiens in the fossil record to specimens which share a significant number of derived features in the skeleton with extant H. sapiens, the origin of our species would be placed in the African late middle Pleistocene, based on fossils such as Omo Kibish 1, Herto 1 and 2, and the Levantine material from Skhul and Qafzeh. However, genetic data suggest that we and our sister species Homo neanderthalensis shared a last common ancestor in the middle Pleistocene approx...

  17. The evolutionary sequence: origin and emergences

    Science.gov (United States)

    Fox, S. W.

    1986-01-01

    The evolutionary sequence is being reexamined experimentally from a "Big Bang"origin to the protocell and from the emergence of protocell and variety of species to Darwin's mental power (mind) and society (The Descent of Man). A most fundamentally revisionary consequence of experiments is an emphasis on endogenous ordering. This principle, seen vividly in ordered copolymerization of amino acids, has had new impact on the theory of Darwinian evolution and has been found to apply to the entire sequence. Herein, I will discuss some problems of dealing with teaching controversial subjects.

  18. CLFV and the origin of neutrino masses

    Science.gov (United States)

    Hambye, Thomas

    2014-03-01

    The neutrino oscillations constitute the unique absolute guarantee we have at the moment that charged lepton flavor violation (CLFV) processes do exist. Even if the associated rates are in general expected very suppressed, it turns out that this is not always necessarily the case. In the framework of the three basic seesaw models, we review the possibilities of having observable rates. Each seesaw case presenting a quite different CLFV pattern, we show how these observable rates could allow us to distinguish these various possible neutrino mass origins.

  19. Genetic and environmental origins of hypospadias

    DEFF Research Database (Denmark)

    Thorup, Jørgen Mogens; Nordenskjöld, Agneta; Hutson, John M

    2014-01-01

    PURPOSE OF REVIEW: The purpose of this study was to review and comment on recent original presentations dealing with genetic and environmental factors in the cause of hypospadias. RECENT FINDINGS: The heritability is definitely high and having an affected family member is the highest identified...... of hypospadias with low birth weight, maternal hypertension, and preeclampsia suggests that placental insufficiency is a major risk factor. Maternal exposure to chemical pollutants or endocrine disruptors in high concentrations related to selected occupations or geographic areas may be additional risk factors...

  20. Origin of axial current in scyllac

    International Nuclear Information System (INIS)

    Sugisaki, K.

    1975-12-01

    The origin of the axial current observed in Scyllac (a high beta stellarator experiment) is discussed. A shaped coil and/or helical winding produce rotational transform which links magnetic lines of force to the plasma column and the axial current is induced electromagnetically. This phenomenon is inherent in a pulsed high-beta stellarator. The rotational transform produced by the induced axial current is much smaller than that associated with the l = 1, 0 equilibrium fields. The effect of the axial current on the equilibrium and stability of the plasma column is thus small. It is also shown that the magnetic field shear near a plasma surface is very strong

  1. Hot origin of the Little Bang

    Energy Technology Data Exchange (ETDEWEB)

    Akkelin, S.V. [Bogolyubov Institute for Theoretical Physics, Kiev (Ukraine); Universitaet Heidelberg, Institut fuer Theoretische Physik, Heidelberg (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, ExtreMe Matter Institute EMMI, Darmstadt (Germany)

    2017-12-15

    Ultrarelativistic heavy ion collisions produce a quark-gluon matter which lies in the future light cone originating from given points on the t = z = 0 plane of the Minkowski spacetime manifold. We show that in a weak coupling regime the Minkowski vacuum of massless fields presents itself in the ''Little Bang'' region as a thermal state of low p{sub T} particles, in close analogy to the Unruh effect for uniformly accelerated observers which are causally restricted to a Rindler wedge. It can shed some light on the mechanisms of early time thermalization in ultrarelativistic heavy ion collisions. (orig.)

  2. Enzymatic recognition of DNA replication origins

    International Nuclear Information System (INIS)

    Stayton, M.M.; Bertsch, L.; Biswas, S.

    1983-01-01

    In this paper we discuss the process of recognition of the complementary-strand origin with emphasis on RNA polymerase action in priming M13 DNA replication, the role of primase in G4 DNA replication, and the function of protein n, a priming protein, during primosome assembly. These phage systems do not require several of the bacterial DNA replication enzymes, particularly those involved in the regulation of chromosome copy number of the initiatiion of replication of duplex DNA. 51 references, 13 figures, 1 table

  3. Origin and Dispersal of Domesticated Peach Palm

    Directory of Open Access Journals (Sweden)

    Charles R. Clement

    2017-11-01

    Full Text Available Peach palm (Bactris gasipaes Kunth is a Neotropical palm domesticated by Native Americans. Its domestication resulted in a set of landraces (var. gasipaes, some with very starchy fruit used for fermentation, others with an equilibrium of starch and oil used as snacks. Which of the three wild types (var. chichagui was involved and where the domestication process began are unclear, with three hypotheses under discussion: an origin in southwestern Amazonia; or in northwestern South America; or multiple origins. We reevaluate one of the wild types, defining it as the incipient domesticate, and then evaluate these hypotheses using the Brazilian peach palm Core Collection and selected herbaria samples to: (1 model the potential distributions of wild and domesticated populations; (2 identify the probable origin of domestication with a phylogeographic analysis of chloroplast DNA sequences; and (3 determine the dispersal routes after domestication using spatial analysis of genetic diversity based on 17 nuclear microsatellite loci. The two very small-fruited wild types have distinct distributions in the northern Andes region and across southern Amazonia, both under moderately humid climates, while the incipient domesticate, partly sympatric with the southern wild type, is also found along the Equatorial Andes, in a more humid climatic envelope, more similar to that of the domesticated landraces. Two distribution models for Last Glacial Maximum conditions (CCSM4, MIROC also suggest distinct distributions for the two wild populations. The chloroplast DNA phylogeographic network confirms the area of sympatry of the incipient domesticate and the southern wild type in southwestern Amazonia as the origin of domestication. The spatial patterns of genetic diversity confirm the proposal of two dispersals, one along the Ucayali River, into western Amazonia, northwestern South America and finally Central America; the other along the Madeira River into central and

  4. Thermodynamic inversion origin of living systems

    CERN Document Server

    Kompanichenko, Vladimir N

    2017-01-01

    This book discusses the theory, general principles, and energy source conditions allowing for the emergence of life in planetary systems. The author examines the material conditions found in natural hydrothermal sites, the appropriate analogs of prebiotic environments on early Earth. He provides an overview of current laboratory experiments in prebiotic materials chemistry and substantiation of a new direction for the experiments in the origin of life field. Describes thermodynamic inversion and how it relates to the living cell; Examines the current direction of experiments on prebiotic materials chemistry; Introduces and substantiates necessary conditions for the emergence of life.

  5. Cerebral Abscess Potentially of Odontogenic Origin

    Directory of Open Access Journals (Sweden)

    Marouene Ben Hadj Hassine

    2015-01-01

    Full Text Available Odontogenic origins are rarely implicated in the formation of brain abscesses. The relative paucity of this kind of infection and the difficulty in matching the causative microorganisms of a brain abscess to an odontogenic source can explain the late management of patients. We herein describe a case of a 46-year-old man with a cerebellar abscess that was probably due to an odontogenic infection. The diagnosis supported by imaging and microscopic identification, mini craniectomy for abscess drainage followed by eradication of all potential dental infectious foci, and an antibiotic regimen based on cephalosporins, metronidazole, and vancomycine contributed to a successful outcome.

  6. Packaging systems for animal origin food

    Directory of Open Access Journals (Sweden)

    2011-03-01

    Full Text Available The main task of food packaging is to protect the product during storage and transport against the action of biological, chemical and mechanical factors. The paper presents packaging systems for food of animal origin. Vacuum and modified atmosphere packagings were characterised together with novel types of packagings, referred to as intelligent packaging and active packaging. The aim of this paper was to present all advantages and disadvantages of packaging used for meat products. Such list enables to choose the optimal type of packaging for given assortment of food and specific conditions of the transport and storing.

  7. Language and the origin of numerical concepts.

    Science.gov (United States)

    Gelman, Rochel; Gallistel, C R

    2004-10-15

    Reports of research with the Pirahã and Mundurukú Amazonian Indians of Brazil lend themselves to discussions of the role of language in the origin of numerical concepts. The research findings indicate that, whether or not humans have an extensive counting list, they share with nonverbal animals a language-independent representation of number, with limited, scale-invariant precision. What causal role, then, does knowledge of the language of counting serve? We consider the strong Whorfian proposal, that of linguistic determinism; the weak Whorfian hypothesis, that language influences how we think; and that the "language of thought" maps to spoken language or symbol systems.

  8. Origin names of gochu, kimchi, and bibimbap

    Directory of Open Access Journals (Sweden)

    Hye-Jeong Yang

    2015-12-01

    Conclusion: Gochu, kimchi, and bibimbap have thousands of years of history and have been called with pure Korean name words. It was only that they were recorded in the form of hanja during the time written Korean was undervalued where people insisted borrowing Chinese characters to write despite written Korean being available. Thus, gocho (苦椒, chimchae (沈菜, and koldonban (滑董飯 are not the origin names. The pure Korean names used even by the people back then are the actual ones: gochyo (고쵸, dimchae (딤, and bubuimbap (부뷤밥.

  9. Mythological and Prehistorical Origins of Neurosurgery.

    Science.gov (United States)

    Nanda, Anil; Filis, Andreas; Kalakoti, Piyush

    2016-05-01

    Mythology has a cultural appeal, and the description of some neurosurgical procedures in the Hindu, Greek, Egyptian, and Chinese mythology has a bearing to the origins of our professions. The traces to some of our modern-day practices also can be linked back to the ancient prehistoric eras of the Siberian, Persian, and the Andean region. In this historical perspective, we briefly dwell into individual accounts through the prism of different cultures to highlight the development of neurosurgery in mythology and prehistoric era. Published by Elsevier Inc.

  10. The origin of the hidden supersymmetry

    International Nuclear Information System (INIS)

    Jakubsky, Vit; Nieto, Luis-Miguel; Plyushchay, Mikhail S.

    2010-01-01

    The hidden supersymmetry and related tri-supersymmetric structure of the free particle system, the Dirac delta potential problem and the Aharonov-Bohm effect (planar, bound state, and tubule models) are explained by a special nonlocal unitary transformation, which for the usual N=2 supercharges has a nature of Foldy-Wouthuysen transformation. We show that in general case, the bosonized supersymmetry of nonlocal, parity even systems emerges in the same construction, and explain the origin of the unusual N=2 supersymmetry of electron in three-dimensional parity even magnetic field. The observation extends to include the hidden superconformal symmetry.

  11. Cosmology and the origin of nuclei

    International Nuclear Information System (INIS)

    Narlikar, Jayant V.

    2010-01-01

    The problem of explaining the origin of all the chemical elements found in the universe is a central problem in astrophysics. In the 1940s Fred Hoyle suggested that they were cooked inside stars, starting with nucleosynthesis of neutrons and protons. In the same decade George Gamow argued that in a hot big bang universe in the first few minutes, the ambient conditions were suitable for formation of nuclei. This paper will review the progress of both these ideas and show that a reasonable compromise between these ideas can be found today. (authors)

  12. Adventist Education: origin, development and expasion

    Directory of Open Access Journals (Sweden)

    Patrick Vieira Ferreira

    2018-03-01

    Full Text Available This article aimed to present a brief historical report of the origin, development and consolidation of the Adventist Education Network. Thus, it will be possible to know about its emergence, philosophy of education and the genesis of this confessional network operating in the Brazilian educational scenario for more than a century. The research method includes bibliographical analysis of the main theoreticians of the Brazilian history of education and rescues facts cited by Adventist historians. The research situated the Adventist Education Network in the Brazilian historical context and identified the Seventh-day Adventists as a religious group and as agents in the field of school education.

  13. Origin of magnetostriction in Fe-Ga

    DEFF Research Database (Denmark)

    Mudivarthi, Chaitanya; Laver, Mark; Cullen, James

    2010-01-01

    This paper investigates the origin of large magnetostriction in Fe-Ga alloys using small-angle neutron scattering (SANS) and Kerr microscopy. The SANS data for a single-crystal, electron irradiated, and quenched Fe81Ga19 sample under externally applied magnetic and elastic fields revealed...... the existence of magnetostrictive nanoclusters spaced at similar to 15 nm apart that have a different magnetization than the A2 matrix. Combining the SANS results and the magnetization orientation obtained from the magnetic domain images using a Kerr microscope, it appears that the nanoclusters contribute...

  14. The origin of the chemical elements

    International Nuclear Information System (INIS)

    Tayler, R.J.

    1984-01-01

    The subject is discussed in relation to the composition of initially created matter and changes which have occurred during the life history of the universe, with particular reference to our galaxy and nearby galaxies. Headings are: observations of element abundances (stars, gas clouds in our own and nearby galaxies, hot gas in galaxy clusters, the solar system); the originally created matter (Big Bang theory and early nuclear reactions); processes changing observed composition (galactic evolution; nuclear fusion reactions in stellar interiors; chemical composition of a highly evolved massive star); supernovae (production of heavy elements); chemical evolution of the galaxy; production of very heavy elements (s process, r process). (U.K.)

  15. The evolutionary sequence: origin and emergences.

    Science.gov (United States)

    Fox, S W

    1986-03-01

    The evolutionary sequence is being reexamined experimentally from a "Big Bang"origin to the protocell and from the emergence of protocell and variety of species to Darwin's mental power (mind) and society (The Descent of Man). A most fundamentally revisionary consequence of experiments is an emphasis on endogenous ordering. This principle, seen vividly in ordered copolymerization of amino acids, has had new impact on the theory of Darwinian evolution and has been found to apply to the entire sequence. Herein, I will discuss some problems of dealing with teaching controversial subjects.

  16. Origin of the matter-antimatter asymmetry

    International Nuclear Information System (INIS)

    Dine, Michael; Kusenko, Alexander

    2004-01-01

    Although the origin of matter-antimatter asymmetry remains unknown, continuing advances in theory and improved experimental limits have ruled out some scenarios for baryogenesis, for example, sphaleron baryogenesis at the electroweak phase transition in the Standard Model. At the same time, the success of cosmological inflation and the prospects for discovering supersymmetry at the Large Hadron Collider have put some other models in sharper focus. We review the current state of our understanding of baryogenesis with emphasis on those scenarios that we consider most plausible

  17. THE ORIGINS AND NATURE OF MONEY

    OpenAIRE

    Mihaela IAVORSCHI

    2014-01-01

    The importance of money and the role they hold in the economy can be seen as the keystone of economic life. For a better understanding of the essence of the monetary phenomena it is especially important to turn to history and see how money was born. By turning to their origins, we discover the real fundaments of monetary issues. Only after such a systematic analysis we will be able to suggest the appropriate solutions for the current monetary issues. Therefore, in this study I will research t...

  18. Biometrics and Psychometrics: Origins, Commonalities and Differences

    Directory of Open Access Journals (Sweden)

    John Gower

    2016-09-01

    Full Text Available Starting with the common origins of biometrics and psychometrics at the beginning of the twentieth century, the paper compares and contrasts subsequent developments, informed by the author's 35 years at Rothamsted Experimental Station followed by a period with the data theory group in Leiden and thereafter. Although the methods used by biometricians and psychometricians have much in common, there are important differences arising from the different fields of study. Similar differences arise wherever data are generated and may be regarded as a major driving force in the development of statistical ideas.

  19. CLFV and the origin of neutrino masses

    International Nuclear Information System (INIS)

    Hambye, Thomas

    2014-01-01

    The neutrino oscillations constitute the unique absolute guarantee we have at the moment that charged lepton flavor violation (CLFV) processes do exist. Even if the associated rates are in general expected very suppressed, it turns out that this is not always necessarily the case. In the framework of the three basic seesaw models, we review the possibilities of having observable rates. Each seesaw case presenting a quite different CLFV pattern, we show how these observable rates could allow us to distinguish these various possible neutrino mass origins

  20. Origin of the earth and moon

    International Nuclear Information System (INIS)

    Ringwood, A.E.

    1981-01-01

    The composition of the Earth's interior and its bearing on the Earth's origin are discussed. It seems likely that the terrestrial planets formed by the accretion of solid planetisimals from the nebula of dust and gas left behind during the formation of the Sun. The scenario proposed is simpler than others. New evidence based upon a comparison of siderophile element abundances in the Earth's mantle and in the Moon imply that the Moon was derived from the Earth's mantle after the Earth's core had segregated

  1. Transitional fossils and the origin of turtles

    OpenAIRE

    Lyson, Tyler R.; Bever, Gabe S.; Bhullar, Bhart-Anjan S.; Joyce, Walter G.; Gauthier, Jacques A.

    2010-01-01

    The origin of turtles is one of the most contentious issues in systematics with three currently viable hypotheses: turtles as the extant sister to (i) the crocodile–bird clade, (ii) the lizard–tuatara clade, or (iii) Diapsida (a clade composed of (i) and (ii)). We reanalysed a recent dataset that allied turtles with the lizard–tuatara clade and found that the inclusion of the stem turtle Proganochelys quenstedti and the ‘parareptile’ Eunotosaurus africanus results in a single overriding morph...

  2. Heterologous production of non-ribosomal peptide LLD-ACV in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Siewers, Verena; Chen, Xiao; Huang, Le

    2009-01-01

    production of ACV was observed. To improve ACV synthesis, several factors were investigated. Codon optimization of the 5′ end of pcbAB did not significantly increase ACV production. However, a 30-fold enhancement was achieved by lowering the cultivation temperature from 30 to 20 °C. When ACVS and PPTase...... encoding genes were integrated into the yeast genome, a 6-fold decrease in ACV production was observed indicating that gene copy number was one of the rate-limiting factors for ACV production in yeast....

  3. Lincosamide Synthetase-A Unique Condensation System Combining Elements of Nonribosomal Peptide Synthetase and Mycothiol Metabolism

    Czech Academy of Sciences Publication Activity Database

    Janata, Jiří; Kadlčík, Stanislav; Koběrská, Markéta; Ulanová, Dana; Kameník, Zdeněk; Novák, Petr; Kopecký, Jan; Novotná, Jitka; Radojevič, Bojana; Plháčková, Kamila; Gažák, Radek; Najmanová, Lucie

    2015-01-01

    Roč. 10, č. 3 (2015) E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) EE2.3.20.0055; GA MŠk(CZ) EE2.3.30.0003 Institutional support: RVO:61388971 Keywords : BIOSYNTHETIC GENE-CLUSTER * MOLECULAR-WEIGHT THIOL * PHOSPHOPANTETHEINYL TRANSFERASE Subject RIV: EE - Microbiology, Virology Impact factor: 3.057, year: 2015

  4. An iterative nonribosomal peptide synthetase assembles the pyrrole-amide antibiotic congocidine in Streptomyces ambofaciens

    Czech Academy of Sciences Publication Activity Database

    Juguet, M.; Lautru, S.; Francou, F.-X.; Nezbedová, Šárka; Leblond, P.; Gondry, M.; Pernodet, J. L.

    2009-01-01

    Roč. 16, č. 4 (2009), s. 421-431 ISSN 1074-5521 Institutional research plan: CEZ:AV0Z50200510 Keywords : ADENYLATION DOMAINS * ESCHERICHIA-COLI * FUNCTIONAL-ANALYSIS Subject RIV: CE - Biochemistry Impact factor: 6.523, year: 2009

  5. Targeted Disruption of Nonribosomal Peptide Synthetase pes3 Augments the Virulence of Aspergillus fumigatus

    DEFF Research Database (Denmark)

    O'Hanlon, Karen A.; Cairns, Timothy; Stack, Deirdre

    2011-01-01

    metabolite profiling revealed that Pes3 does not produce a secreted or intracellularly stored NRP in A. fumigatus. Macrophage infections and histological analysis of infected murine tissue indicate that Δpes3 heightened virulence appears to be mediated by aberrant innate immune recognition of the fungus....... Proteome alterations in A. fumigatus Δpes3 strongly suggest impaired germination capacity. Uniquely, our data strongly indicate a structural role for the Pes3-encoded NRP, a finding that appears to be novel for an NRP synthetase....

  6. Cell wall peptidolipids of Mycobacterium avium: from genetic prediction to exact structure of a nonribosomal peptide

    Science.gov (United States)

    Total lipids from an M. avium subsp. paratuberculosis (Map) ovine strain (S-type) contained no identifiable glycopeptidolipids or lipopentapeptide, yet both lipids are present in other M. avium subspecies. We determined the genetic and phenotypic basis for this difference using sequence analysis and...

  7. Homochirality and the origin of life

    Science.gov (United States)

    Pohl, Robert; Leitner, J. J.; Firneis, M. G.

    2012-05-01

    Homochirality is generally considered a crucial signature for life on Earth, which uses left-handed amino acids and right-handed sugars. A mirror-image life, using right-handed amino acids and left- handed sugars, is perfectly conceivable and might have developed on another planet. Life which would simultaneously use both right- and left-handed forms of the same biological molecules is unlikely for geometrical reasons. Secondary peptide structures are not possible without one-handedness. Various theories try to explain the origin of homochirality. Physicists used as argument the phenomenon of parity violation discovered on 60Co, which does not explain homochirality on prebiotic substances. Astrophysicists suggested that the observed enantiomeric excesses could have been induced by circularly polarized light arising from dust scattering in regions of high mass star formations or even due to super nova remnants or pulsars. An extraterrestrial origin of homochiral substances is discusses as well as catalytic processes on early Earth using different mineral surfaces. Thermodynamics i.e. its 2nd law is considered to explain homochirality as consequence of increasing entropy. There are many questions not yet answered. The author looks forward to discuss some of them with interested scientists.

  8. Phylogenomic reconstruction supports supercontinent origins for Leishmania.

    Science.gov (United States)

    Harkins, Kelly M; Schwartz, Rachel S; Cartwright, Reed A; Stone, Anne C

    2016-03-01

    Leishmania, a genus of parasites transmitted to human hosts and mammalian/reptilian reservoirs by an insect vector, is the causative agent of the human disease complex leishmaniasis. The evolutionary relationships within the genus Leishmania and its origins are the source of ongoing debate, reflected in conflicting phylogenetic and biogeographic reconstructions. This study employs a recently described bioinformatics method, SISRS, to identify over 200,000 informative sites across the genome from newly sequenced and publicly available Leishmania data. This dataset is used to reconstruct the evolutionary relationships of this genus. Additionally, we constructed a large multi-gene dataset, using it to reconstruct the phylogeny and estimate divergence dates for species. We conclude that the genus Leishmania evolved at least 90-100 million years ago, supporting a modified version of the Multiple Origins hypothesis that we call the Supercontinent hypothesis. According to this scenario, separate Leishmania clades emerged prior to, and during, the breakup of Gondwana. Additionally, we confirm that reptile-infecting Leishmania are derived from mammalian forms and that the species that infect porcupines and sloths form a clade long separated from other species. Finally, we firmly place the guinea-pig infecting species, Leishmaniaenriettii, the globally dispersed Leishmaniasiamensis, and the newly identified Australian species from a kangaroo, as sibling species whose distribution arises from the ancient connection between Australia, Antarctica, and South America. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Evidence for a recent origin of penguins

    Science.gov (United States)

    Subramanian, Sankar; Beans-Picón, Gabrielle; Swaminathan, Siva K.; Millar, Craig D.; Lambert, David M.

    2013-01-01

    Penguins are a remarkable group of birds, with the 18 extant species living in diverse climatic zones from the tropics to Antarctica. The timing of the origin of these extant penguins remains controversial. Previous studies based on DNA sequences and fossil records have suggested widely differing times for the origin of the group. This has given rise to widely differing biogeographic narratives about their evolution. To resolve this problem, we sequenced five introns from 11 species representing all genera of living penguins. Using these data and other available DNA sequences, together with the ages of multiple penguin fossils to calibrate the molecular clock, we estimated the age of the most recent common ancestor of extant penguins to be 20.4 Myr (17.0–23.8 Myr). This time is half of the previous estimates based on molecular sequence data. Our results suggest that most of the major groups of extant penguins diverged 11–16 Ma. This overlaps with the sharp decline in Antarctic temperatures that began approximately 12 Ma, suggesting a possible relationship between climate change and penguin evolution. PMID:24227045

  10. Jigsaw model of the origin of life

    Science.gov (United States)

    McGowan, John F.

    2002-02-01

    It is suggested that life originated in a three-step process referred to as the jigsaw model. RNA, proteins, or similar organic molecules polymerized in a dehydrated carbon-rich environment, on surfaces in a carbon-rich environment, or in another environment where polymerization occurs. These polymers subsequently entered an aqueous environment where they folded into compact structures. It is argued that the folding of randomly generated polymers such as RNA or proteins in water tends to partition the folded polymer into domains with hydrophobic cores and matching shapes to minimize energy. In the aqueous environment hydrolysis or other reactions fragmented the compact structures into two or more matching molecules, occasionally producing simple living systems, also knows as autocatalytic sets of molecules. It is argued that the hydrolysis of folded polymers such as RNA or proteins is not random. The hydrophobic cores of the domains are rarely bisected due to the energy requirements in water. Hydrolysis preferentially fragments the folded polymers into pieces with complementary structures and chemical affinities. Thus the probability of producing a system of matched, interacting molecules in prebiotic chemistry is much higher than usually estimated. Environments where this process may occur are identified. For example, the jigsaw model suggests life may have originated at a seep or carbonaceous fluids beneath the ocean. The polymerization occurred beneath the sea floor. The folding and fragmentation occurred in the ocean. The implications of this hypothesis for seeking life or prebiotic chemistry in the Solar System are explored.

  11. Original Framework for Optimizing Hybrid Energy Supply

    Directory of Open Access Journals (Sweden)

    Amevi Acakpovi

    2016-01-01

    Full Text Available This paper proposes an original framework for optimizing hybrid energy systems. The recent growth of hybrid energy systems in remote areas across the world added to the increasing cost of renewable energy has triggered the inevitable development of hybrid energy systems. Hybrid energy systems always pose a problem of optimization of cost which has been approached with different perspectives in the recent past. This paper proposes a framework to guide the techniques of optimizing hybrid energy systems in general. The proposed framework comprises four stages including identification of input variables for energy generation, establishment of models of energy generation by individual sources, development of artificial intelligence, and finally summation of selected sources. A case study of a solar, wind, and hydro hybrid system was undertaken with a linear programming approach. Substantial results were obtained with regard to how load requests were constantly satisfied while minimizing the cost of electricity. The developed framework gained its originality from the fact that it has included models of individual sources of energy that even make the optimization problem more complex. This paper also has impacts on the development of policies which will encourage the integration and development of renewable energies.

  12. The origins and evolution of leadership.

    Science.gov (United States)

    King, Andrew J; Johnson, Dominic D P; Van Vugt, Mark

    2009-10-13

    How groups of individuals achieve coordination and collective action is an important topic in the natural sciences, but until recently the role of leadership in this process has been largely overlooked. In contrast, leadership is arguably one of the most important themes in the social sciences, permeating all aspects of human social affairs: the election of Barack Obama, the war in Iraq, and the collapse of the banks are all high-profile events that draw our attention to the fundamental role of leadership and followership. Converging ideas and developments in both the natural and social sciences suggest that leadership and followership share common properties across humans and other animals, pointing to ancient roots and evolutionary origins. Here, we draw upon key insights from the animal and human literature to lay the foundation for a new science of leadership inspired by an evolutionary perspective. Identifying the origins of human leadership and followership, as well as which aspects are shared with other animals and which are unique, offers ways of understanding, predicting, and improving leadership today.

  13. Origin, lineage and function of cerebellar glia.

    Science.gov (United States)

    Buffo, Annalisa; Rossi, Ferdinando

    2013-10-01

    The glial cells of the cerebellum, and particularly astrocytes and oligodendrocytes, are characterized by a remarkable phenotypic variety, in which highly peculiar morphological features are associated with specific functional features, unique among the glial cells of the entire CNS. Here, we provide a critical report about the present knowledge of the development of cerebellar glia, including lineage relationships between cerebellar neurons, astrocytes and oligodendrocytes, the origins and the genesis of the repertoire of glial types, and the processes underlying their acquisition of mature morphological and functional traits. In parallel, we describe and discuss some fundamental roles played by specific categories of glial cells during cerebellar development. In particular, we propose that Bergmann glia exerts a crucial scaffolding activity that, together with the organizing function of Purkinje cells, is necessary to achieve the normal pattern of foliation and layering of the cerebellar cortex. Moreover, we discuss some of the functional tasks of cerebellar astrocytes and oligodendrocytes that are distinctive of cerebellar glia throughout the CNS. Notably, we report about the regulation of synaptic signalling in the molecular and granular layer mediated by Bergmann glia and parenchymal astrocytes, and the functional interaction between oligodendrocyte precursor cells and neurons. On the whole, this review provides an extensive overview of the available literature and some novel insights about the origin and differentiation of the variety of cerebellar glial cells and their function in the developing and mature cerebellum. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Probing the evolutionary origins of music perception.

    Science.gov (United States)

    McDermott, Josh; Hauser, Marc D

    2005-12-01

    Empirical data have recently begun to inform debates on the evolutionary origins of music. In this paper we discuss some of our recent findings and related theoretical issues. We claim that theories of the origins of music will be usefully constrained if we can determine which aspects of music perception are innate, and, of those, which are uniquely human and specific to music. Comparative research in nonhuman animals, particularly nonhuman primates, is thus critical to the debate. In this paper we focus on the preferences that characterize most humans' experience of music, testing whether similar preferences exist in nonhuman primates. Our research suggests that many rudimentary acoustic preferences, such as those for consonant over dissonant intervals, may be unique to humans. If these preferences prove to be innate in humans, they may be candidates for music-specific adaptations. To establish whether such preferences are innate in humans, one important avenue for future research will be the collection of data from different cultures. This may be facilitated by studies conducted over the internet.

  15. Reptile thermogenesis and the origins of endothermy.

    Science.gov (United States)

    Tattersall, Glenn J

    2016-10-01

    Extant endotherms have high rates of metabolism, elevated body temperatures, usually tight control over body temperature, and a reasonable scope for further increases in metabolism through locomotor activity. Vertebrate ectotherms, on the other hand, rely on behavioural thermoregulation and cardiovascular adjustments to facilitate warming, and generally lack specific biochemical and cellular mechanisms for sustained, elevated metabolism. Nevertheless, the ancestral condition to endothermy is thought to resemble that of many extant reptiles, which raises the question of the origins and selection pressures relevant to the transitional state. Numerous hypotheses have emerged to explain the multiple origins of endothermy in vertebrates, including thermoregulatory, locomotory, and reproductive activity as possible drivers for these sustained and elevated metabolic rates. In this article, I discuss recent evidence for facultative endothermy in an extant lepidosaur, the tegu lizard. Since lepidosaurs are a sister group to the archosaurs, understanding how a novel form of endothermy evolved will open up opportunities to test the compatibility or incompatibility of the various endothermy hypotheses, with potential to elucidate and resolve long contentious ideas in evolutionary physiology. Copyright © 2016 Elsevier GmbH. All rights reserved.

  16. Origins of anti-DNA autoantibodies

    International Nuclear Information System (INIS)

    Schwartz, R.S.

    1985-01-01

    The direction of research in autoimmunity was strongly influenced by three notable discoveries made more than 25 year ago: anti-DNA anti-bodies in lupus serum, the immunofluorescent antinuclar antibody test and the NZB mouse. Now another turning point has been reached for three new reasons: the discovery of the hybridoma technic, advances in cellular immunology and the use of molecular biology to solve immunological problems. These developments have motivated fresh approaches to questions about the origins and pathogenic mechanisms of autoantibodies. Systemic lupus erythematosus (SLE) has a conspicuous position in the field of autoimmunity for several reasons. Its diverse manifestations have attracted a correspondingly diverse group of investigators whose interests range from molecular biology to therapeutic trials; superb models of the disease occur spontaneously in animals; and the extensive variety of autoantibodies in SLE provides an abundance of investigative reagents. An explanation of the origins of these autoantibodies is one of the major goals of research in the disease. The autoantibodies that bind to DNA are of central interest. They occur in almost all patients with active SLE, they often fluctuate with its clinical activity, and they participate in forming its lesions

  17. Bending sound in graphene: Origin and manifestation

    Energy Technology Data Exchange (ETDEWEB)

    Adamyan, V.M., E-mail: vadamyan@onu.edu.ua [Department of Theoretical Physics, Odessa I.I. Mechnikov National University, 2 Dvoryanska St., Odessa 65026 (Ukraine); Bondarev, V.N., E-mail: bondvic@onu.edu.ua [Department of Theoretical Physics, Odessa I.I. Mechnikov National University, 2 Dvoryanska St., Odessa 65026 (Ukraine); Zavalniuk, V.V., E-mail: vzavalnyuk@onu.edu.ua [Department of Theoretical Physics, Odessa I.I. Mechnikov National University, 2 Dvoryanska St., Odessa 65026 (Ukraine); Department of Fundamental Sciences, Odessa Military Academy, 10 Fontanska Road, Odessa 65009 (Ukraine)

    2016-11-11

    Highlights: • The origin of sound-like dispersion of graphene bending mode is disclosed. • The speed of graphene bending sound is determined. • The renormalized graphene bending rigidity is derived. • The intrinsic corrugations of graphene are estimated. - Abstract: It is proved that the acoustic-type dispersion of bending mode in graphene is generated by the fluctuation interaction between in-plane and out-of-plane terms in the free energy arising with account of non-linear components in the graphene strain tensor. In doing so we use an original adiabatic approximation based on the alleged (confirmed a posteriori) significant difference of sound speeds for in-plane and bending modes. The explicit expression for the bending sound speed depending only on the graphene mass density, in-plane elastic constants and temperature is deduced as well as the characteristics of the microscopic corrugations of graphene. The obtained results are in good quantitative agreement with the data of real experiments and computer simulations.

  18. Bending sound in graphene: Origin and manifestation

    International Nuclear Information System (INIS)

    Adamyan, V.M.; Bondarev, V.N.; Zavalniuk, V.V.

    2016-01-01

    Highlights: • The origin of sound-like dispersion of graphene bending mode is disclosed. • The speed of graphene bending sound is determined. • The renormalized graphene bending rigidity is derived. • The intrinsic corrugations of graphene are estimated. - Abstract: It is proved that the acoustic-type dispersion of bending mode in graphene is generated by the fluctuation interaction between in-plane and out-of-plane terms in the free energy arising with account of non-linear components in the graphene strain tensor. In doing so we use an original adiabatic approximation based on the alleged (confirmed a posteriori) significant difference of sound speeds for in-plane and bending modes. The explicit expression for the bending sound speed depending only on the graphene mass density, in-plane elastic constants and temperature is deduced as well as the characteristics of the microscopic corrugations of graphene. The obtained results are in good quantitative agreement with the data of real experiments and computer simulations.

  19. Origins of food crops connect countries worldwide

    Science.gov (United States)

    Achicanoy, Harold A.; Bjorkman, Anne D.; Navarro-Racines, Carlos; Guarino, Luigi; Flores-Palacios, Ximena; Engels, Johannes M. M.; Wiersema, John H.; Dempewolf, Hannes; Sotelo, Steven; Ramírez-Villegas, Julian; Castañeda-Álvarez, Nora P.; Fowler, Cary; Jarvis, Andy; Rieseberg, Loren H.; Struik, Paul C.

    2016-01-01

    Research into the origins of food plants has led to the recognition that specific geographical regions around the world have been of particular importance to the development of agricultural crops. Yet the relative contributions of these different regions in the context of current food systems have not been quantified. Here we determine the origins (‘primary regions of diversity’) of the crops comprising the food supplies and agricultural production of countries worldwide. We estimate the degree to which countries use crops from regions of diversity other than their own (‘foreign crops’), and quantify changes in this usage over the past 50 years. Countries are highly interconnected with regard to primary regions of diversity of the crops they cultivate and/or consume. Foreign crops are extensively used in food supplies (68.7% of national food supplies as a global mean are derived from foreign crops) and production systems (69.3% of crops grown are foreign). Foreign crop usage has increased significantly over the past 50 years, including in countries with high indigenous crop diversity. The results provide a novel perspective on the ongoing globalization of food systems worldwide, and bolster evidence for the importance of international collaboration on genetic resource conservation and exchange.

  20. RNA Relics and Origin of Life

    Directory of Open Access Journals (Sweden)

    Laurent Vial

    2009-07-01

    Full Text Available A number of small RNA sequences, located in different non-coding sequences and highly preserved across the tree of life, have been suggested to be molecular fossils, of ancient (and possibly primordial origin. On the other hand, recent years have revealed the existence of ubiquitous roles for small RNA sequences in modern organisms, in functions ranging from cell regulation to antiviral activity. We propose that a single thread can be followed from the beginning of life in RNA structures selected only for stability reasons through the RNA relics and up to the current coevolution of RNA sequences; such an understanding would shed light both on the history and on the present development of the RNA machinery and interactions. After presenting the evidence (by comparing their sequences that points toward a common thread, we discuss a scenario of genome coevolution (with emphasis on viral infectious processes and finally propose a plan for the reevaluation of the stereochemical theory of the genetic code; we claim that it may still be relevant, and not only for understanding the origin of life, but also for a comprehensive picture of regulation in present-day cells.

  1. RNA Relics and Origin of Life

    Science.gov (United States)

    Demongeot, Jacques; Glade, Nicolas; Moreira, Andrés; Vial, Laurent

    2009-01-01

    A number of small RNA sequences, located in different non-coding sequences and highly preserved across the tree of life, have been suggested to be molecular fossils, of ancient (and possibly primordial) origin. On the other hand, recent years have revealed the existence of ubiquitous roles for small RNA sequences in modern organisms, in functions ranging from cell regulation to antiviral activity. We propose that a single thread can be followed from the beginning of life in RNA structures selected only for stability reasons through the RNA relics and up to the current coevolution of RNA sequences; such an understanding would shed light both on the history and on the present development of the RNA machinery and interactions. After presenting the evidence (by comparing their sequences) that points toward a common thread, we discuss a scenario of genome coevolution (with emphasis on viral infectious processes) and finally propose a plan for the reevaluation of the stereochemical theory of the genetic code; we claim that it may still be relevant, and not only for understanding the origin of life, but also for a comprehensive picture of regulation in present-day cells. PMID:20111682

  2. Origin and significance of defects in welds

    International Nuclear Information System (INIS)

    Lundin, C.D.

    1984-01-01

    In the past 10 to 15 years significant advances have taken place in the understanding of the origin and nature of weld discontinuities. The furthering of the knowledge of hot cracking, cold cracking, lamellar tearing and porosity formation is due to the development and utilization of sophisticated techniques for microscopy and microanalysis and the concerted efforts of many researchers in the U.S. and abroad. Concurrent with the progress toward better definition of the metallurgical mechanisms for discontinuity formation, the development of the fracture mechanics approach for the assessment of the significance of the discontinuities was brought into focus. It is the marriage of the metallurgical understanding of formation and the mechanics assessment of relevance that permits discontinuities to be treated with a new degree of sophistication. The many types of cracking and porosity formation were the subjects of numerous studies in the intervening years. This presentation will treat the various types of weld discontinuities which have their origin closely related to a metallurgical mechanism. Emphasis will be placed on hot cracking, and porosity formation with information presented on cold cracking, reheat cracking and lamellar tearing. The employment of the newer metallurgical tools will be discussed in terms of their utilization in determining the cause of discontinuity formation

  3. Possible evolutionary origins of cognitive brain lateralization.

    Science.gov (United States)

    Vallortigara, G; Rogers, L J; Bisazza, A

    1999-08-01

    Despite the substantial literature on the functional architecture of the asymmetries of the human brain, which has been accumulating for more than 130 years since Dax and Broca's early reports, the biological foundations of cerebral asymmetries are still poorly understood. Recent advances in comparative cognitive neurosciences have made available new animal models that have started to provide unexpected insights into the evolutionary origins and neuronal mechanisms of cerebral asymmetries. Animal model-systems, particularly those provided by the avian brain, highlight the interrelations of genetic, hormonal and environmental events to produce neural and behavioural asymmetries. Novel evidences showing that functional and structural lateralization of the brain is widespread among vertebrates (including fish, reptiles and amphibians) have accumulated rapidly. Perceptual asymmetries, in particular, seem to be ubiquitous in everyday behaviour of most species of animals with laterally placed eyes; in organisms with wider binocular overlap (e.g., amphibians), they appear to be retained for initial detection of stimuli in the extreme lateral fields. We speculate that adjustment of head position and eye movements may play a similar role in mammals with frontal vision as does the choice for right or left lateral visual fields in animals with laterally placed eyes. A first attempt to trace back the origins of brain asymmetry to early vertebrates is presented, based on the hypothesis that functional incompatibility between the logical demands associated with very basic cognitive functions is central to the phenomenon of cerebral lateralization.

  4. Evolutionary origin of the turtle shell.

    Science.gov (United States)

    Lyson, Tyler R; Bever, Gabe S; Scheyer, Torsten M; Hsiang, Allison Y; Gauthier, Jacques A

    2013-06-17

    The origin of the turtle shell has perplexed biologists for more than two centuries. It was not until Odontochelys semitestacea was discovered, however, that the fossil and developmental data could be synthesized into a model of shell assembly that makes predictions for the as-yet unestablished history of the turtle stem group. We build on this model by integrating novel data for Eunotosaurus africanus-a Late Guadalupian (∼260 mya) Permian reptile inferred to be an early stem turtle. Eunotosaurus expresses a number of relevant characters, including a reduced number of elongate trunk vertebrae (nine), nine pairs of T-shaped ribs, inferred loss of intercostal muscles, reorganization of respiratory muscles to the ventral side of the ribs, (sub)dermal outgrowth of bone from the developing perichondral collar of the ribs, and paired gastralia that lack both lateral and median elements. These features conform to the predicted sequence of character acquisition and provide further support that E. africanus, O. semitestacea, and Proganochelys quenstedti represent successive divergences from the turtle stem lineage. The initial transformations of the model thus occurred by the Middle Permian, which is congruent with molecular-based divergence estimates for the lineage, and remain viable whether turtles originated inside or outside crown Diapsida. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Deep Mantle Origin for the DUPAL Anomaly?

    Science.gov (United States)

    Ingle, S.; Weis, D.

    2002-12-01

    Twenty years after the discovery of the Dupal Anomaly, its origin remains a geochemical and geophysical enigma. This anomaly is associated with the Southern Hemisphere oceanic mantle and is recognized by basalts with geochemical characteristics such as low 206Pb/204Pb and high 87Sr/86Sr. Both mid-ocean ridge basalts (MORB) and ocean island basalts (OIB) are affected, despite originating from melting at different depths and of different mantle sources. We compile geochemical data for both MORB and OIB from the three major oceans to help constrain the physical distribution and chemical composition of the Dupal Anomaly. There is a clear decrease in 206Pb/204Pb and an increase in 87Sr/86Sr with more southerly latitude for Indian MORB and OIB; these correlations are less obvious in the Atlantic and non-existent in the Pacific. The average* 143Nd/144Nd for Pacific and Atlantic OIB is 0.5129, but is lower for Indian OIB (0.5128). Interestingly, Pacific, Atlantic and Indian OIB all have 176Hf/177Hf averages of 0.2830. Indian MORB also record this phenomenon of low Nd with normal Hf isotopic compositions (Chauvel and Blichert-Toft, EPSL, 2001). Hf isotopes appear, therefore, to be a valid isotopic proxy for measuring the presence and magnitude of the Dupal Anomaly at specific locations. Wen (EPSL, 2001) reported a low-velocity layer at the D'' boundary beneath the Indian Ocean from which the Dupal Anomaly may originate. This hypothesis may be consistent with our compilations demonstrating that the long-lived Dupal Anomaly does not appear to be either mixing efficiently into the upper mantle or spreading to other ocean basins through time. We suggest that the Dupal source could be continually tapped by upwelling Indian Ocean mantle plumes. Plumes would then emplace pockets of Dupal material into the upper mantle and other ascending plumes might further disperse this material into the shallow asthenosphere. This could explain both the presence of the Dupal signature in MORB

  6. Origins of geothermal gases at Yellowstone

    Science.gov (United States)

    Lowenstern, Jacob B.; Bergfeld, Deborah; Evans, William C.; Hunt, Andrew G.

    2015-01-01

    Gas emissions at the Yellowstone Plateau Volcanic Field (YPVF) reflect open-system mixing of gas species originating from diverse rock types, magmas, and crustal fluids, all combined in varying proportions at different thermal areas. Gases are not necessarily in chemical equilibrium with the waters through which they vent, especially in acid sulfate terrain where bubbles stream through stagnant acid water. Gases in adjacent thermal areas often can be differentiated by isotopic and gas ratios, and cannot be tied to one another solely by shallow processes such as boiling-induced fractionation of a parent liquid. Instead, they inherit unique gas ratios (e.g., CH4/He) from the dominant rock reservoirs where they originate, some of which underlie the Quaternary volcanic rocks. Steam/gas ratios (essentially H2O/CO2) of Yellowstone fumaroles correlate with Ar/He and N2/CO2, strongly suggesting that H2O/CO2 is controlled by addition of steam boiled from water rich in atmospheric gases. Moreover, H2O/CO2 varies systematically with geographic location, such that boiling is more enhanced in some areas than others. The δ13C and 3He/CO2 of gases reflect a dominant mantle origin for CO2 in Yellowstone gas. The mantle signature is most evident at Mud Volcano, which hosts gases with the lowest H2O/CO2, lowest CH4 concentrations and highest He isotope ratios (~16Ra), consistent with either a young subsurface intrusion or less input of crustal and meteoric gas than any other location at Yellowstone. Across the YPVF, He isotope ratios (3He/4He) inversely vary with He concentrations, and reflect varied amounts of long- stored, radiogenic He added to the magmatic endmember within the crust. Similarly, addition of CH4 from organic-rich sediments is common in the eastern thermal areas at Yellowstone. Overall, Yellowstone gases reflect addition of deep, high-temperature magmatic gas (CO2-rich), lower-temperatures crustal gases (4He- and CH4-bearing), and those gases (N2, Ne, Ar) added

  7. Organic Minerals in the Origin of Life

    Science.gov (United States)

    Benner, S.; Biondi, E.; Kim, H. J.

    2017-12-01

    Models for the origin of life are plagued by fundamental problems that, due to their difficulty, are called "paradoxes". One of these, known to anyone who has ever worked in a kitchen, is that organics, when given energy and left to itself, does not generate life. Rather, organics devolve to give tarry mixtures that become increasingly complex and increasingly less likely to support life (like asphalt). However, even if those mixtures escape devolution to create something useful for Darwinism, like building blocks for RNA, the water in which they must work is corrosive, leading to their destruction. Even if RNA is created, it is itself easily degraded. One current trend to manage those paradoxes turns to minerals in environments on early Earth. Inorganic minerals containing borate have now been shown to prevent the destruction of ribose (the R in RNA) and other carbohydrates essential for early Earth. Evaporite desert basins supplied with aqueous runoff from tourmaline-containing basalts are ideal environments for forming borate minerals, especially if they are made alkaline by serpentinizing peridotite. In the evaporite environments, drying cycles mitigate the destructive capability of water. Further, we have shown that phosphate is segregated from calcium (avoiding formation of relatively unreacted apatites) if magnesium and borate are present. Further, a common magnesium borophosphate (luneburgite) not only makes phosphate available for prebiotic synthesis, but selectively phosphorylates RNA building blocks as it releases borate to stabilize them against further degradation. Finally, a variety of minerals bind and stabilize RNA itself. Research in this area has also discovered organic minerals that might have been relevant to the origins of life on Earth. Such minerals are scarce on Earth today, since they are easily consumed by microbial communities. However, on a prebiotic Earth, organic minerals could have stored organic species as intermediates towards our

  8. Origins of Life: Open Questions and Debates

    Science.gov (United States)

    Brack, André

    2017-10-01

    Stanley Miller demonstrated in 1953 that it was possible to form amino acids from methane, ammonia, and hydrogen in water, thus launching the ambitious hope that chemists would be able to shed light on the origins of life by recreating a simple life form in a test tube. However, it must be acknowledged that the dream has not yet been accomplished, despite the great volume of effort and innovation put forward by the scientific community. A minima, primitive life can be defined as an open chemical system, fed with matter and energy, capable of self-reproduction (i.e., making more of itself by itself), and also capable of evolving. The concept of evolution implies that chemical systems would transfer their information fairly faithfully but make some random errors. If we compared the components of primitive life to parts of a chemical automaton, we could conceive that, by chance, some parts self-assembled to generate an automaton capable of assembling other parts to produce a true copy. Sometimes, minor errors in the building generated a more efficient automaton, which then became the dominant species. Quite different scenarios and routes have been followed and tested in the laboratory to explain the origin of life. There are two schools of thought in proposing the prebiotic supply of organics. The proponents of a metabolism-first call for the spontaneous formation of simple molecules from carbon dioxide and water to rapidly generate life. In a second hypothesis, the primeval soup scenario, it is proposed that rather complex organic molecules accumulated in a warm little pond prior to the emergence of life. The proponents of the primeval soup or replication first approach are by far the more active. They succeeded in reconstructing small-scale versions of proteins, membranes, and RNA. Quite different scenarios have been proposed for the inception of life: the RNA world, an origin within droplets, self-organization counteracting entropy, or a stochastic approach merging

  9. Origins of Protein Functions in Cells

    Science.gov (United States)

    Seelig, Burchard; Pohorille, Andrzej

    2011-01-01

    In modern organisms proteins perform a majority of cellular functions, such as chemical catalysis, energy transduction and transport of material across cell walls. Although great strides have been made towards understanding protein evolution, a meaningful extrapolation from contemporary proteins to their earliest ancestors is virtually impossible. In an alternative approach, the origin of water-soluble proteins was probed through the synthesis and in vitro evolution of very large libraries of random amino acid sequences. In combination with computer modeling and simulations, these experiments allow us to address a number of fundamental questions about the origins of proteins. Can functionality emerge from random sequences of proteins? How did the initial repertoire of functional proteins diversify to facilitate new functions? Did this diversification proceed primarily through drawing novel functionalities from random sequences or through evolution of already existing proto-enzymes? Did protein evolution start from a pool of proteins defined by a frozen accident and other collections of proteins could start a different evolutionary pathway? Although we do not have definitive answers to these questions yet, important clues have been uncovered. In one example (Keefe and Szostak, 2001), novel ATP binding proteins were identified that appear to be unrelated in both sequence and structure to any known ATP binding proteins. One of these proteins was subsequently redesigned computationally to bind GTP through introducing several mutations that introduce targeted structural changes to the protein, improve its binding to guanine and prevent water from accessing the active center. This study facilitates further investigations of individual evolutionary steps that lead to a change of function in primordial proteins. In a second study (Seelig and Szostak, 2007), novel enzymes were generated that can join two pieces of RNA in a reaction for which no natural enzymes are known

  10. The origins of tropical marine biodiversity.

    Science.gov (United States)

    Bowen, Brian W; Rocha, Luiz A; Toonen, Robert J; Karl, Stephen A

    2013-06-01

    Recent phylogeographic studies have overturned three paradigms for the origins of marine biodiversity. (i) Physical (allopatric) isolation is not the sole avenue for marine speciation: many species diverge along ecological boundaries. (ii) Peripheral habitats such as oceanic archipelagos are not evolutionary graveyards: these regions can export biodiversity. (iii) Speciation in marine and terrestrial ecosystems follow similar processes but are not the same: opportunities for allopatric isolation are fewer in the oceans, leaving greater opportunity for speciation along ecological boundaries. Biodiversity hotspots such as the Caribbean Sea and the Indo-Pacific Coral Triangle produce and export species, but can also accumulate biodiversity produced in peripheral habitats. Both hotspots and peripheral ecosystems benefit from this exchange in a process dubbed biodiversity feedback. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. The National Origins of Policy Ideas

    DEFF Research Database (Denmark)

    Campbell, John L.; Pedersen, Ove K.

    In politics, ideas matter. They provide the foundation for economic policymaking, which in turn shapes what is possible in domestic and international politics. Yet until now, little attention has been paid to how these ideas are produced and disseminated, and how this process varies between...... countries. The National Origins of Policy Ideas provides the first comparative analysis of how "knowledge regimes" communities of policy research organizations like think tanks, political party foundations, ad hoc commissions, and state research offices, and the institutions that govern them generate ideas...... and communicate them to policymakers. John Campbell and Ove Pedersen examine how knowledge regimes are organized, operate, and have changed over the last thirty years in the United States, France, Germany, and Denmark. They show how there are persistent national differences in how policy ideas are produced. Some...

  12. Dynamic origins of fermionic D -terms

    Science.gov (United States)

    Hudson, Jonathan; Schweitzer, Peter

    2018-03-01

    The D -term is defined through matrix elements of the energy-momentum tensor, similarly to mass and spin, yet this important particle property is experimentally not known any fermion. In this work we show that the D -term of a spin 1/2 fermion is of dynamical origin: it vanishes for a free fermion. This is in pronounced contrast to the bosonic case where already a free spin-0 boson has a non-zero intrinsic D -term. We illustrate in two simple models how interactions generate the D -term of a fermion with an internal structure, the nucleon. All known matter is composed of elementary fermions. This indicates the importance to study this interesting particle property in more detail, which will provide novel insights especially on the structure of the nucleon.

  13. Traditional and ayurvedic foods of Indian origin

    Directory of Open Access Journals (Sweden)

    Preetam Sarkar

    2015-09-01

    Full Text Available The Ayurveda contains a wealth of knowledge on health sciences. Accordingly traditional foods and their dietary guidelines are prescribed in Ayurveda. There is so much similarity in ayurvedic dietetics and traditional foods that many of the traditional health foods in India can be called ayurvedic foods. This review article introduces the concepts of ayurvedic health foods in India and describes several traditional heath foods across various regions of India. Recommended dietary guidelines according to age and health condition of the consumer, and seasonal considerations are presented for each of the traditional health foods of India. In the era of globalization of the population and international food trading, health conscious citizens around the globe will benefit from the wealth of knowledge on traditional Indian and ayurvedic health foods of Indian origin.

  14. Origins and challenges of viral dark matter.

    Science.gov (United States)

    Krishnamurthy, Siddharth R; Wang, David

    2017-07-15

    The accurate classification of viral dark matter - metagenomic sequences that originate from viruses but do not align to any reference virus sequences - is one of the major obstacles in comprehensively defining the virome. Depending on the sample, viral dark matter can make up from anywhere between 40 and 90% of sequences. This review focuses on the specific nature of dark matter as it relates to viral sequences. We identify three factors that contribute to the existence of viral dark matter: the divergence and length of virus sequences, the limitations of alignment based classification, and limited representation of viruses in reference sequence databases. We then discuss current methods that have been developed to at least partially circumvent these limitations and thereby reduce the extent of viral dark matter. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Origins the scientific story of creation

    CERN Document Server

    Baggott, Jim

    2015-01-01

    What is the nature of the material world? How does it work? What is the universe and how was it formed? What is life? Where do we come from and how did we evolve? How and why do we think? What does it mean to be human? How do we know? There are many different versions of our creation story. This book tells the version according to modern science. It is a unique account, starting at the Big Bang and travelling right up to the emergence of humans as conscious intelligent beings, 13.8 billion years later. Chapter by chapter, it sets out the current state of scientific knowledge: the origins of space and time; energy, mass, and light; galaxies, stars, and our sun; the habitable earth, and complex life itself. Drawing together the physical and biological sciences, Baggott recounts what we currently know of our history, highlighting the questions science has yet to answer.

  16. The National Origins of Policy Ideas

    DEFF Research Database (Denmark)

    Campbell, John L.; Pedersen, Ove K.

    countries. The National Origins of Policy Ideas provides the first comparative analysis of how "knowledge regimes" communities of policy research organizations like think tanks, political party foundations, ad hoc commissions, and state research offices, and the institutions that govern them generate ideas...... contexts. Drawing on extensive interviews with top officials at leading policy research organizations, this book demonstrates why knowledge regimes are as important to capitalism as the state and the firm, and sheds new light on debates about the effects of globalization, the rise of neoliberalism......In politics, ideas matter. They provide the foundation for economic policymaking, which in turn shapes what is possible in domestic and international politics. Yet until now, little attention has been paid to how these ideas are produced and disseminated, and how this process varies between...

  17. Computational logic: its origins and applications.

    Science.gov (United States)

    Paulson, Lawrence C

    2018-02-01

    Computational logic is the use of computers to establish facts in a logical formalism. Originating in nineteenth century attempts to understand the nature of mathematical reasoning, the subject now comprises a wide variety of formalisms, techniques and technologies. One strand of work follows the 'logic for computable functions (LCF) approach' pioneered by Robin Milner, where proofs can be constructed interactively or with the help of users' code (which does not compromise correctness). A refinement of LCF, called Isabelle, retains these advantages while providing flexibility in the choice of logical formalism and much stronger automation. The main application of these techniques has been to prove the correctness of hardware and software systems, but increasingly researchers have been applying them to mathematics itself.

  18. The Origin and Dynamics of Solar Magnetism

    CERN Document Server

    Thompson, M. J; Culhane, J. L; Nordlund, Å; Solanki, S. K; Zahn, J.-P

    2009-01-01

    The articles collected in this volume present all aspects of solar magnetism: from its origin in the solar dynamo to its evolution and dynamics that create the variability of solar phenomena, its well-known 11-year activity cycle that leads to the ever-changing pattern of sunspots and active regions on the Sun. Several contributions deal with the solar dynamo, the driver of many solar phenomena. Other contributions treat the transport and emergence of the magnetic flux through the outer layers of the Sun. The coupling of magnetic fields from the surface to the solar corona and beyond is also described, together with current studies on the predictability of solar activity. This book is aimed at researchers and graduate students working in solar physics and space science. It provides a full review of our current understanding of solar magnetism by the foremost experts in the field.

  19. The Probe of Inflation and Cosmic Origins

    Science.gov (United States)

    Hanany, Shaul; Inflation Probe Mission Study Team

    2018-01-01

    The Probe of Inflation and Cosmic Origins will map the polarization of the cosmic microwave background over the entire sky with unprecedented sensitivity. It will search for gravity wave signals from the inflationary epoch, thus probing quantum gravity and constraining the energy scale of inflation; it will test the standard model of particle physics by measuring the number of light particles in the Universe and the mass of the neutrino; it will elucidate the nature of dark matter and search for new forms of matter in the early Universe; it will constrain star formation history over cosmic time; and it will determine the mechanisms of structure formation from galaxy cluster to stellar scales. I will review the status of design of this probe-scale mission.

  20. Searching for the origin of masses

    International Nuclear Information System (INIS)

    Iwasaki, Hiroyuki

    2002-01-01

    The origin of masses of weak gauge bosons as well as quarks and leptons is one of the most mysterious themes in high energy physics. In the standard model, it is explained as a result of a spontaneous symmetry breaking of the vacuum, which is caused by self-interaction of an unknown complex scalar field. Three weak gauge bosons acquire their masses by 'eating' the three components of the scalar field. The remaining one component survives and called the 'Higgs boson'. Masses of quarks and leptons are generated by an interaction between those particles and the scalar field. Searching for the Higgs boson is a key step toward deeper understanding of nature. In the lecture, a brief introduction of theoretical aspects and an experimental approach based on an ongoing project will be given

  1. LHC and the origin of neutrino mass

    International Nuclear Information System (INIS)

    Senjanovic, Goran

    2008-01-01

    It is often said that neutrino mass is a window to a new physics beyond the standard model (SM). This is true if neutrinos are Majorana particles for the SM with Majorana neutrino mass is not a complete theory. The classical text-book test of neutrino Majorana mass, the neutrino-less double beta decay depends on the completion, and thus cannot probe neutrino mass. As pointed out already twenty five years ago, the colliders such as Tevatron or LHC offer a hope of probing directly the origin of neutrino (Majorana) mass through lepton number violating production of like sign lepton pairs. I make a case here for this in the context of all three types of seesaw mechanism.

  2. Management of spent solvents of reprocessing origin

    International Nuclear Information System (INIS)

    Manohar, S.; Srinivas, C.; Vincent, T.; Wattal, P.K.

    2001-01-01

    Spent solvents of reprocessing origin constitute a major portion of radioactive liquid organic wastes arising from nuclear activity. An in-depth study of this waste stream has led to the evolution of a complete management option, which addresses not only the concern of radioactivity but also its organic nature. This is based on alkaline hydrolysis of Tri-n-butyl phosphate (TBP), which converts it into aqueous soluble products, viz. sodium salt of dibutyl phosphoric acid and butanol. During the process of alkaline hydrolysis almost all the activity associated with the waste gets transferred into the aqueous phase. The recovered diluent virtually free of activity and TBP can be recycled, and in case of it not meeting reprocessing standards, can be incinerated. The process generated aqueous waste is found compatible with cement and can be immobilized in cement matrix. (author)

  3. The 'spiteful' origins of human cooperation.

    Science.gov (United States)

    Marlowe, Frank W; Berbesque, J Colette; Barrett, Clark; Bolyanatz, Alexander; Gurven, Michael; Tracer, David

    2011-07-22

    We analyse generosity, second-party ('spiteful') punishment (2PP), and third-party ('altruistic') punishment (3PP) in a cross-cultural experimental economics project. We show that smaller societies are less generous in the Dictator Game but no less prone to 2PP in the Ultimatum Game. We might assume people everywhere would be more willing to punish someone who hurt them directly (2PP) than someone who hurt an anonymous third person (3PP). While this is true of small societies, people in large societies are actually more likely to engage in 3PP than 2PP. Strong reciprocity, including generous offers and 3PP, exists mostly in large, complex societies that face numerous challenging collective action problems. We argue that 'spiteful' 2PP, motivated by the basic emotion of anger, is more universal than 3PP and sufficient to explain the origins of human cooperation.

  4. Hematopoietic stem cell origin of connective tissues.

    Science.gov (United States)

    Ogawa, Makio; Larue, Amanda C; Watson, Patricia M; Watson, Dennis K

    2010-07-01

    Connective tissue consists of "connective tissue proper," which is further divided into loose and dense (fibrous) connective tissues and "specialized connective tissues." Specialized connective tissues consist of blood, adipose tissue, cartilage, and bone. In both loose and dense connective tissues, the principal cellular element is fibroblasts. It has been generally believed that all cellular elements of connective tissue, including fibroblasts, adipocytes, chondrocytes, and bone cells, are generated solely by mesenchymal stem cells. Recently, a number of studies, including those from our laboratory based on transplantation of single hematopoietic stem cells, strongly suggested a hematopoietic stem cell origin of these adult mesenchymal tissues. This review summarizes the experimental evidence for this new paradigm and discusses its translational implications. Copyright 2010 ISEH - Society for Hematology and Stem Cells. All rights reserved.

  5. Classical algebra its nature, origins, and uses

    CERN Document Server

    Cooke, Roger L

    2008-01-01

    This insightful book combines the history, pedagogy, and popularization of algebra to present a unified discussion of the subject. Classical Algebra provides a complete and contemporary perspective on classical polynomial algebra through the exploration of how it was developed and how it exists today. With a focus on prominent areas such as the numerical solutions of equations, the systematic study of equations, and Galois theory, this book facilitates a thorough understanding of algebra and illustrates how the concepts of modern algebra originally developed from classical algebraic precursors. This book successfully ties together the disconnect between classical and modern algebraand provides readers with answers to many fascinating questions that typically go unexamined, including: What is algebra about? How did it arise? What uses does it have? How did it develop? What problems and issues have occurred in its history? How were these problems and issues resolved? The author answers these questions and more,...

  6. Cosmology and the origin of structure

    CERN Multimedia

    Kolb, Edward W; CERN. Geneva. Audiovisual Unit

    2002-01-01

    There is now strong evidence that the rich and varied structure we see in the universe today in the form of stars, galaxies, galaxy clusters, and even larger structures, grew from small primordial 'seeds' that were planted in the first second in the history of the universe. The last decade has seen remarkable advances in observational cosmology, highlighted by the observations of galaxies in the deep universe and the observation of primordial fluctuations in the microwave background. With the increasing accuracy and sophistication of astronomical observations, the details of our theory for the growth of structure will be tested. These lectures will serve as an introduction to the generation and growth of structure in the universe. The series of four lectures will follow the program: Lecture 1: The observed universe Lecture 2: The growth of cosmological structure Lecture 3: Inflation and the origin of perturbations Lecture 4: Dark matter and dark energy

  7. Stellar alchemy. The celestial origin of atoms

    Science.gov (United States)

    Cassé, Michel

    Why do the stars shine? What messages can we read in the light they send to us from the depths of the night? Nuclear astrophysics is a fascinating discipline, and enables connections to be made between atoms, stars, and human beings. Through modern astronomy, scientists have managed to unravel the full history of the chemical elements, and to understand how they originated and evolved into all the elements that compose our surroundings today. The transformation of metals into gold, something once dreamed of by alchemists, is a process commonly occurring in the cores of massive stars. But the most exciting revelation is the intimate connection that humanity itself has with the debris of exploded stars. This engaging account of nucleosynthesis in stars, and the associated chemical evolution of the Universe, is suitable for the general reader.

  8. The origin of metal impurities in DIVA

    International Nuclear Information System (INIS)

    Ohasa, Kazumi; Sengoku, Seio; Maeda, Hikosuke; Ohtsuka, Hideo; Yamamoto, Shin

    1978-10-01

    The origin of metal impurities in DIVA (JFT-2a Tokamak) has been studied experimentally. Three processes of metal impurity release from the first wall were identified; i.e. ion sputtering, evaporation, and arcing. Among of these, ion sputtering is the predominant process in the quiet phase of the discharge, which is characterized by no spikes in the loop voltage and no localized heat flux concentrations on the first wall. ''Cones'' formation due to the sputtering is observed on the gold protection plate (guard limiter) exposed to about 10,000 discharges by scanning electron micrograph. In the SEM photographs, the spacial distribution of cones on the shell surface due to the ion sputtering coincides with the spacial distribution of intensity of Au-I line radiation. Gold is the dominant metal impurity in DIVA. The honeycomb structure can decrease release of the metal impurity. (author)

  9. Origin of the universe and high energy

    International Nuclear Information System (INIS)

    Montoya Z, M.

    1994-01-01

    In this book it is briefly exposed what it is done in the world in relation with the high energy physics. Also, it is presented a brief historical description of the earth evolution, the universe and physics in general. This book counts with eight chapters. The first chapter deals with the relationship of man with science. The second chapter speaks about the origin of universe. The third chapter comments about the stars and galaxies formation. The fourth chapter treats how the scientists and researchers continue to studying the subnuclear world. The fifth chapter deals with subjects and models of nuclear physics. In the sixth chapter it is described the function of the particles accelerator. The seventh chapter comments about the multidisciplinary aspects of the research of elementary particles. Finally, the eighth chapter deals with the advances of high energy physics in the andean region of Latin America. (author)

  10. The Origin and Diversification of Birds.

    Science.gov (United States)

    Brusatte, Stephen L; O'Connor, Jingmai K; Jarvis, Erich D

    2015-10-05

    Birds are one of the most recognizable and diverse groups of modern vertebrates. Over the past two decades, a wealth of new fossil discoveries and phylogenetic and macroevolutionary studies has transformed our understanding of how birds originated and became so successful. Birds evolved from theropod dinosaurs during the Jurassic (around 165-150 million years ago) and their classic small, lightweight, feathered, and winged body plan was pieced together gradually over tens of millions of years of evolution rather than in one burst of innovation. Early birds diversified throughout the Jurassic and Cretaceous, becoming capable fliers with supercharged growth rates, but were decimated at the end-Cretaceous extinction alongside their close dinosaurian relatives. After the mass extinction, modern birds (members of the avian crown group) explosively diversified, culminating in more than 10,000 species distributed worldwide today. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. The endoskeletal origin of the turtle carapace

    Science.gov (United States)

    Hirasawa, Tatsuya; Nagashima, Hiroshi; Kuratani, Shigeru

    2013-01-01

    The turtle body plan, with its solid shell, deviates radically from those of other tetrapods. The dorsal part of the turtle shell, or the carapace, consists mainly of costal and neural bony plates, which are continuous with the underlying thoracic ribs and vertebrae, respectively. Because of their superficial position, the evolutionary origins of these costo-neural elements have long remained elusive. Here we show, through comparative morphological and embryological analyses, that the major part of the carapace is derived purely from endoskeletal ribs. We examine turtle embryos and find that the costal and neural plates develop not within the dermis, but within deeper connective tissue where the rib and intercostal muscle anlagen develop. We also examine the fossils of an outgroup of turtles to confirm that the structure equivalent to the turtle carapace developed independently of the true osteoderm. Our results highlight the hitherto unravelled evolutionary course of the turtle shell. PMID:23836118

  12. On the origins of endogenous thoughts.

    Science.gov (United States)

    Tillas, Alexandros

    2017-05-01

    Endogenous thoughts are thoughts that we activate in a top-down manner or in the absence of the appropriate stimuli. We use endogenous thoughts to plan or recall past events. In this sense, endogenous thinking is one of the hallmarks of our cognitive lives. In this paper, I investigate how it is that we come to possess endogenous control over our thoughts. Starting from the close relation between language and thinking, I look into speech production-a process motorically controlled by the inferior frontal gyrus (IFG). Interestingly, IFG is also closely related to silent talking, as well as volition. The connection between IFG and volition is important given that endogenous thoughts are or at least greatly resemble voluntary actions. Against this background, I argue that IFG is key to understanding the origins of conscious endogenous thoughts. Furthermore, I look into goal-directed thinking and show that IFG plays a key role also in unconscious endogenous thinking.

  13. Colonial Origins of the Port of Buenaventura

    Directory of Open Access Journals (Sweden)

    Alonso Valencia Llano

    2014-07-01

    Full Text Available This article studies the origins of the Port of Buenaventura in the New Kingdom of Granada. It begins with the process of exploration of the coastal territory in order to highlight the different sites in which it was situated, demonstrating that it began as a river port and was later resituated and gradually converted into a maritime port. In addition, this article analyzes the problems it faced, such as the dificulty of communication with the interior of the country, the indigenous resistance that caused the destruction of the town, and inally the necessity of populating the zone with black slaves in order to exploit the mining border. This study also discusses how this port was controlled by the elite of the city of Cali, until the Republican period when it became the sole Colombian port on the Paciic Ocean.

  14. Origin of holographic dark energy models

    International Nuclear Information System (INIS)

    Myung, Yun Soo; Seo, Min-Gyun

    2009-01-01

    We investigate the origin of holographic dark energy models which were recently proposed to explain the dark energy-dominated universe. For this purpose, we introduce the spacetime foam uncertainty of δl≥l p α l α-1 . It was argued that the case of α=2/3 could describe the dark energy with infinite statistics, while the case of α=1/2 can describe the ordinary matter with Bose-Fermi statistics. However, two cases may lead to the holographic energy density if the latter recovers from the geometric mean of UV and IR scales. Hence the dark energy with infinite statistics based on the entropy bound is not an ingredient for deriving the holographic dark energy model. Furthermore, it is shown that the agegraphic dark energy models are the holographic dark energy model with different IR length scales

  15. Theory of Tatar Origin of the Yakuts

    Directory of Open Access Journals (Sweden)

    V.V. Ushnitsky

    2014-01-01

    Full Text Available The article examines the problem of the origin of the people of Sakha (Yakutia in the light of the latest research. Basing on archaeological materials the ethnogenesis of Sakha is associated with the Baikal region’s Ust’-Tal’kinsky archaeological culture of the 12th–14th centuries. Analysis of written sources allows to associate representatives of Ust’-Tal’kinsky archaeological culture with the Usutu-mangun tribe identical with the Angara Tatars and referred to in the writings of Rashid al-Din and Abu al-Ghazi. Probably, the Angara Tatars migrated from Central Asia and compactly inhabited the Angara region near Lake Buir-Nur. The article analyzes connection between Sakha folklore sources and real history of Central Asian Tatars.

  16. Newton and the origin of civilization

    CERN Document Server

    Buchwald, Jed Z

    2012-01-01

    Isaac Newton's Chronology of Ancient Kingdoms Amended, published in 1728, one year after the great man's death, unleashed a storm of controversy. And for good reason. The book presents a drastically revised timeline for ancient civilizations, contracting Greek history by five hundred years and Egypt's by a millennium. Newton and the Origin of Civilization tells the story of how one of the most celebrated figures in the history of mathematics, optics, and mechanics came to apply his unique ways of thinking to problems of history, theology, and mythology, and of how his radical ideas produced an uproar that reverberated in Europe's learned circles throughout the eighteenth century and beyond. Jed Buchwald and Mordechai Feingold reveal the manner in which Newton strove for nearly half a century to rectify universal history by reading ancient texts through the lens of astronomy, and to create a tight theoretical system for interpreting the evolution of civilization on the basis of population dynamics. It was duri...

  17. Upheaval Dome, Utah, USA: Impact origin confirmed

    Science.gov (United States)

    Buchner, Elmar; Kenkmann, Thomas

    2008-03-01

    Upheaval Dome is a unique circular structure on the ColoradoPlateau in SE Utah, the origin of which has been controversiallydiscussed for decades. It has been interpreted as a crypto volcanicfeature, a salt diapir, a pinched-off salt diapir, and an erodedimpact crater. While recent structural mapping, modeling, andanalyses of deformation mechanisms strongly support an impactorigin, ultimate proof, namely the documentation of unambiguousshock features, has yet to be successfully provided. In thisstudy, we document, for the first time, shocked quartz grainsfrom this crater in sandstones of the Jurassic Kayenta Formation.The investigated grains contain multiple sets of decorated planardeformation features. Transmission electron microscopy (TEM)reveals that the amorphous lamellae are annealed and exhibitdense tangles of dislocations as well as trails of fluid inclusions.The shocked quartz grains were found in the periphery of thecentral uplift in the northeastern sector of the crater, whichmost likely represents the cross range crater sector.

  18. Modern turtle origins: the oldest known cryptodire.

    Science.gov (United States)

    Gaffney, E S; Hutchison, J H; Jenkins, F A; Meeker, L J

    1987-07-17

    The discovery of a turtle in the Early Jurassic(185 million years before present) Kayenta Formation of northeastern Arizona provides significant evidence about the origin of modern turtles. This new taxon possesses many of the primitive features expected in the hypothetical common ancestor of pleurodires and cryptodires, the two groups of modern turtles. It is identified as the oldest known cryptodire because of the presence of a distinctive cryptodiran jaw mechanism consisting of a trochlea over the otic chamber that redirects the line of action of the adductor muscle. Aquatic habits appear to have developed very early in turtle evolution. Kayentachelys extends the known record of cryptodires back at least 45 million years and documents a very early stage in the evolution of modern turtles.

  19. Germline V repertoires: Origin, maintenance, diversification.

    Science.gov (United States)

    Steele, E J; Lindley, R A

    2018-06-01

    In our view, Melvin Cohn (Scand J Immunol. 2018;87:e12640) has set out the logical guidelines towards a resolution of the very real enigma of the selectability of vertebrate germline Ig V repertoires under the current evolutionary paradigm…" A somatically derived repertoire scrambles this (germline VL + VH) substrate so that its specificities are lost, making it un-selectable in the germline. Consequently, evolution faced an incompatibility." It is argued here in Reply that a reverse transcriptase-based soma-to-germline process (S->G) targeting germline V segment arrays goes some considerable way to resolving fundamental contradictions on the origin, maintenance and then real-time adaptive diversification of these limited sets of V segments encoded within various V repertoire arrays. © 2018 The Foundation for the Scandinavian Journal of Immunology.

  20. An origin of life on Mars.

    Science.gov (United States)

    McKay, Christopher P

    2010-04-01

    Evidence of past liquid water on the surface of Mars suggests that this world once had habitable conditions and leads to the question of life. If there was life on Mars, it would be interesting to determine if it represented a separate origin from life on Earth. To determine the biochemistry and genetics of life on Mars requires that we have access to an organism or the biological remains of one-possibly preserved in ancient permafrost. A way to determine if organic material found on Mars represents the remains of an alien biological system could be based on the observation that biological systems select certain organic molecules over others that are chemically similar (e.g., chirality in amino acids).

  1. Origins of human cooperation and morality.

    Science.gov (United States)

    Tomasello, Michael; Vaish, Amrisha

    2013-01-01

    From an evolutionary perspective, morality is a form of cooperation. Cooperation requires individuals either to suppress their own self-interest or to equate it with that of others. We review recent research on the origins of human morality, both phylogenetic (research with apes) and ontogenetic (research with children). For both time frames we propose a two-step sequence: first a second-personal morality in which individuals are sympathetic or fair to particular others, and second an agent-neutral morality in which individuals follow and enforce group-wide social norms. Human morality arose evolutionarily as a set of skills and motives for cooperating with others, and the ontogeny of these skills and motives unfolds in part naturally and in part as a result of sociocultural contexts and interactions.

  2. An original approach to data acquisition CHADAC

    CERN Document Server

    CERN. Geneva

    1981-01-01

    Many labs try to boost existing data acquisition systems by inserting high performance intelligent devices in the important nodes of the system's structure. This strategy finds its limits in the system's architecture. The CHADAC project proposes a simple and efficient solution to this problem, using a multiprocessor modular architecture. CHADAC main features are: parallel acquisition of data; CHADAC is fast, it dedicates one processor per branch and each processor can read and store one 16 bit word in 800 ns; original structure; each processor can work in its own private memory, in its own shared memory (double access) and in the shared memory of any other processor. Simple and fast communications between processors are also provided by local DMAs; flexibility; each processor is autonomous and may be used as an independent acquisition system for a branch, by connecting local peripherals to it. Adjunction of fast trigger logic is possible. By its architecture and performances, CHADAC is designed to provide a g...

  3. Paleoparasitology: the origin of human parasites

    Directory of Open Access Journals (Sweden)

    Adauto Araujo

    2013-09-01

    Full Text Available Parasitism is composed by three subsystems: the parasite, the host, and the environment. There are no organisms that cannot be parasitized. The relationship between a parasite and its host species most of the time do not result in damage or disease to the host. However, in a parasitic disease the presence of a given parasite is always necessary, at least in a given moment of the infection. Some parasite species that infect humans were inherited from pre-hominids, and were shared with other phylogenetically close host species, but other parasite species were acquired from the environment as humans evolved. Human migration spread inherited parasites throughout the globe. To recover and trace the origin and evolution of infectious diseases, paleoparasitology was created. Paleoparasitology is the study of parasites in ancient material, which provided new information on the evolution, paleoepidemiology, ecology and phylogenetics of infectious diseases.

  4. Origin of the Societe des Americanistes, Paris

    Directory of Open Access Journals (Sweden)

    David L. Browman

    1998-11-01

    Full Text Available Pascal Riviale (1991 produced a two volume dissertation summarizing the work of French scholars involved in anthropology, ethnography, and archaeology in Peru from the beginning of Peruvian independence in 1821 up until World War 1. From the commentary, it is clear that not only does this volume trace individual scholars, and institu­tions involved in archaeologically-related research, but it develops a number of general intellectual themes as well. Riviale has recently (1996 extracted a portion of his dissertation relating to the events leading up to the founding of the Society of Americanists, Paris, in 1895. Because he is focusing in this case on the origin of a specific organiza­tion, he concentrates on exegesis of the institutional antecedents from 1821 onward.

  5. On the origin of delta spots

    International Nuclear Information System (INIS)

    Tang, F.

    1983-01-01

    Mount Wilson sunspot drawings from 1966 through 1980 were used in conjunction with Hα filtergrams from Big Bear Solar Observatory to examine the origin of delta spots, spots with bipolar umbrae within one penumbra. Of the six cases we studied, five were formed by the union of non-paired spots. They are either shoved into one another by two neighboring growing bipoles or by a new spot born piggy-back style on an existing spot of opposite polarity. Proper motions of the growing spots take on curvilinear paths around one another to avoid a collision. This is the shear motion observed in delta spots (Tanaka, 1979). In the remaining case, the delta spot was formed by spots that emerged as a pair. Our findings indicate no intrinsic differences in the formation or the behavior between delta spots of normal magnetic configuration. (orig.)

  6. An Origin of Life on Mars

    Science.gov (United States)

    McKay, Christopher P.

    2010-01-01

    Evidence of past liquid water on the surface of Mars suggests that this world once had habitable conditions and leads to the question of life. If there was life on Mars, it would be interesting to determine if it represented a separate origin from life on Earth. To determine the biochemistry and genetics of life on Mars requires that we have access to an organism or the biological remains of one—possibly preserved in ancient permafrost. A way to determine if organic material found on Mars represents the remains of an alien biological system could be based on the observation that biological systems select certain organic molecules over others that are chemically similar (e.g., chirality in amino acids). PMID:20452949

  7. Searching the Arcane Origins of Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Angel Garrido

    2011-05-01

    Full Text Available It is well-known that Artificial Intelligence requires Logic. But its Classical version shows too many insufficiencies. So, it is very necessary to introduce more sophisticated tools, as may be
    Fuzzy Logic, Modal Logic, Non-Monotonic Logic, and so on. When you are searching the possible precedent of such new ideas, we may found that they are not totally new, because some ancient thinkers have suggested many centuries ago similar concepts, certainly without adequate mathematical formulation, but in the same line: against the dogmatism and the dualistic vision of
    the world: absolutely true vs. absolutely false, black vs. white, good or bad by nature, 0 vs.1, etc. We attempt to analyze here some of these greatly unexplored, and very interesting early origins.

  8. Bone Marrow Adipocyte Developmental Origin and Biology.

    Science.gov (United States)

    Bukowska, Joanna; Frazier, Trivia; Smith, Stanley; Brown, Theodore; Bender, Robert; McCarthy, Michelle; Wu, Xiying; Bunnell, Bruce A; Gimble, Jeffrey M

    2018-06-01

    This review explores how the relationships between bone marrow adipose tissue (BMAT) adipogenesis with advancing age, obesity, and/or bone diseases (osteopenia or osteoporosis) contribute to mechanisms underlying musculoskeletal pathophysiology. Recent studies have re-defined adipose tissue as a dynamic, vital organ with functions extending beyond its historic identity restricted solely to that of an energy reservoir or sink. "State of the art" methodologies provide novel insights into the developmental origin, physiology, and function of different adipose tissue depots. These include genetic tracking of adipose progenitors, viral vectors application, and sophisticated non-invasive imaging modalities. While constricted within the rigid bone cavity, BMAT vigorously contributes to local and systemic metabolic processes including hematopoiesis, osteogenesis, and energy metabolism and undergoes dynamic changes as a function of age, diet, bone topography, or sex. These insights will impact future research and therapies relating to osteoporosis.

  9. Little string origin of surface defects

    Energy Technology Data Exchange (ETDEWEB)

    Haouzi, Nathan; Schmid, Christian [Center for Theoretical Physics, University of California, Berkeley,LeConte Hall, Berkeley (United States)

    2017-05-16

    We derive a large class of codimension-two defects of 4d N=4 Super Yang-Mills (SYM) theory from the (2,0) little string. The origin of the little string is type IIB theory compactified on an ADE singularity. The defects are D-branes wrapping the 2-cycles of the singularity. We use this construction to make contact with the description of SYM defects due to Gukov and Witten https://arxiv.org/abs/hep-th/0612073. Furthermore, we provide a geometric perspective on the nilpotent orbit classification of codimension-two defects, and the connection to ADE-type Toda CFT. The only data needed to specify the defects is a set of weights of the algebra obeying certain constraints, which we give explicitly. We highlight the differences between the defect classification in the little string theory and its (2,0) CFT limit.

  10. The Origins of Scintillator Non-Proportionality

    Science.gov (United States)

    Moses, W. W.; Bizarri, G. A.; Williams, R. T.; Payne, S. A.; Vasil'ev, A. N.; Singh, J.; Li, Q.; Grim, J. Q.; Choong, W.-S.

    2012-10-01

    Recent years have seen significant advances in both theoretically understanding and mathematically modeling the underlying causes of scintillator non-proportionality. The core cause is that the interaction of radiation with matter invariably leads to a non-uniform ionization density in the scintillator, coupled with the fact that the light yield depends on the ionization density. The mechanisms that lead to the luminescence dependence on ionization density are incompletely understood, but several important features have been identified, notably Auger-like processes (where two carriers of excitation interact with each other, causing one to de-excite non-radiatively), the inability of excitation carriers to recombine (caused either by trapping or physical separation), and the carrier mobility. This paper reviews the present understanding of the fundamental origins of scintillator non-proportionality, specifically the various theories that have been used to explain non-proportionality.

  11. On the Origin of Hyperfast Neutron Stars

    Science.gov (United States)

    Gvaramadze, V. V.; Gualandris, A.; Portegies Zwart, S.

    2008-05-01

    We propose an explanation for the origin of hyperfast neutron stars (e.g. PSR B1508+55, PSR B2224+65, RX J0822 4300) based on the hypothesis that they could be the remnants of a symmetric supernova explosion of a high-velocity massive star (or its helium core) which attained its peculiar velocity (similar to that of the neutron star) in the course of a strong three- or four-body dynamical encounter in the core of a young massive star cluster. This hypothesis implies that the dense cores of star clusters (located either in the Galactic disk or near the Galactic centre) could also produce the so-called hypervelocity stars ordinary stars moving with a speed of ~ 1 000 km s-1.

  12. Originals and reproductions: information society challenges

    Directory of Open Access Journals (Sweden)

    Vilenka Jakac-Bizjak

    2001-01-01

    Full Text Available Due to digitisation of traditional documents new collections of electronic publications/resources are formed. The article deals with the process of planning of digitisation of library materials on traditional media, accompanying decisions and procedures, as well as methods of storage and preservation of digitised materials, the impact of target public on the decision about what to digitise and the questions of copyright. Acquisition and preservation of new media has an important influence on the work of libraries, especially on collection development. Parallel to these changes new technical terms develop, as for example information resources management.In the introduction, the author actualise the thought of Walter Benjamin on the impact of reproduction techniques on the status of original documents and on the separation of tradition from what was reproduced. The question whether digitisation changes the principles of national libraries underlying the preservation of national cultural heritage is raised.

  13. Transitional fossils and the origin of turtles.

    Science.gov (United States)

    Lyson, Tyler R; Bever, Gabe S; Bhullar, Bhart-Anjan S; Joyce, Walter G; Gauthier, Jacques A

    2010-12-23

    The origin of turtles is one of the most contentious issues in systematics with three currently viable hypotheses: turtles as the extant sister to (i) the crocodile-bird clade, (ii) the lizard-tuatara clade, or (iii) Diapsida (a clade composed of (i) and (ii)). We reanalysed a recent dataset that allied turtles with the lizard-tuatara clade and found that the inclusion of the stem turtle Proganochelys quenstedti and the 'parareptile' Eunotosaurus africanus results in a single overriding morphological signal, with turtles outside Diapsida. This result reflects the importance of transitional fossils when long branches separate crown clades, and highlights unexplored issues such as the role of topological congruence when using fossils to calibrate molecular clocks.

  14. Leptogenesis as the origin of matter

    International Nuclear Information System (INIS)

    Buchmueller, W.; Peccei, R.D.; Yanagida, T.

    2005-02-01

    We explore in some detail the hypothesis that the generation of a primordial lepton-antilepton asymmetry (Leptogenesis) early on in the history of the Universe is the root cause for the origin of matter. After explaining the theoretical conditions for producing a matter-antimatter asymmetry in the Universe we detail how, through sphaleron processes, it is possible to transmute a lepton asymmetry- or, more precisely, a (B-L)-asymmetry- into a baryon asymmetry. Because Leptogenesis depends in detail on properties of the neutrino spectrum, we review briefly existing experimental information on neutrinos as well as the seesaw mechanism, which offers a theoretical understanding of why neutrinos are so light. The bulk of the Review is devoted to a discussion of thermal Leptogenesis and we show that for the neutrino spectrum suggested by oscillation experiments one obtains the observed value for the baryon to photon density ratio in the Universe, independently of any initial boundary conditions. In the latter part of the Review we consider how well Leptogenesis fits with particle physics models of dark matter. Although axionic dark matter and Leptogenesis can be very naturally linked, there is a potential clash between Leptogenesis and models of supersymmetric dark matter because the high temperature needed for Leptogenesis leads to an overproduction of gravitinos, which alter the standard predictions of big bang nucleosynthesis. This problem can be resolved, but it constrains the supersymmetric spectrum at low energies and the nature of the LSP. Finally, as an illustration of possible other options for the origin of matter, we discuss the possibility that Leptogenesis may occur as a result of non-thermal processes. (orig.)

  15. The Evolutionary Origin of Female Orgasm.

    Science.gov (United States)

    Pavličev, Mihaela; Wagner, Günter

    2016-09-01

    The evolutionary explanation of female orgasm has been difficult to come by. The orgasm in women does not obviously contribute to the reproductive success, and surprisingly unreliably accompanies heterosexual intercourse. Two types of explanations have been proposed: one insisting on extant adaptive roles in reproduction, another explaining female orgasm as a byproduct of selection on male orgasm, which is crucial for sperm transfer. We emphasize that these explanations tend to focus on evidence from human biology and thus address the modification of a trait rather than its evolutionary origin. To trace the trait through evolution requires identifying its homologue in other species, which may have limited similarity with the human trait. Human female orgasm is associated with an endocrine surge similar to the copulatory surges in species with induced ovulation. We suggest that the homolog of human orgasm is the reflex that, ancestrally, induced ovulation. This reflex became superfluous with the evolution of spontaneous ovulation, potentially freeing female orgasm for other roles. This is supported by phylogenetic evidence showing that induced ovulation is ancestral, while spontaneous ovulation is derived within eutherians. In addition, the comparative anatomy of female reproductive tract shows that evolution of spontaneous ovulation is correlated with increasing distance of clitoris from the copulatory canal. In summary, we suggest that the female orgasm-like trait may have been adaptive, however for a different role, namely for inducing ovulation. With the evolution of spontaneous ovulation, orgasm was freed to gain secondary roles, which may explain its maintenance, but not its origin. © 2016 Wiley Periodicals, Inc.

  16. Origin and diversification of TRIM ubiquitin ligases.

    Directory of Open Access Journals (Sweden)

    Ignacio Marín

    Full Text Available Most proteins of the TRIM family (also known as RBCC family are ubiquitin ligases that share a peculiar protein structure, characterized by including an N-terminal RING finger domain closely followed by one or two B-boxes. Additional protein domains found at their C termini have been used to classify TRIM proteins into classes. TRIMs are involved in multiple cellular processes and many of them are essential components of the innate immunity system of animal species. In humans, it has been shown that mutations in several TRIM-encoding genes lead to diverse genetic diseases and contribute to several types of cancer. They had been hitherto detected only in animals. In this work, by comprehensively analyzing the available diversity of TRIM and TRIM-like protein sequences and evaluating their evolutionary patterns, an improved classification of the TRIM family is obtained. Members of one of the TRIM subfamilies defined, called Subfamily A, turn to be present not only in animals, but also in many other eukaryotes, such as fungi, apusozoans, alveolates, excavates and plants. The rest of subfamilies are animal-specific and several of them originated only recently. Subfamily A proteins are characterized by containing a MATH domain, suggesting a potential evolutionary connection between TRIM proteins and a different type of ubiquitin ligases, known as TRAFs, which contain quite similar MATH domains. These results indicate that the TRIM family emerged much earlier than so far thought and contribute to our understanding of its origin and diversification. The structural and evolutionary links with the TRAF family of ubiquitin ligases can be experimentally explored to determine whether functional connections also exist.

  17. The origin and evolution of Homo sapiens.

    Science.gov (United States)

    Stringer, Chris

    2016-07-05

    If we restrict the use of Homo sapiens in the fossil record to specimens which share a significant number of derived features in the skeleton with extant H. sapiens, the origin of our species would be placed in the African late middle Pleistocene, based on fossils such as Omo Kibish 1, Herto 1 and 2, and the Levantine material from Skhul and Qafzeh. However, genetic data suggest that we and our sister species Homo neanderthalensis shared a last common ancestor in the middle Pleistocene approximately 400-700 ka, which is at least 200 000 years earlier than the species origin indicated from the fossils already mentioned. Thus, it is likely that the African fossil record will document early members of the sapiens lineage showing only some of the derived features of late members of the lineage. On that basis, I argue that human fossils such as those from Jebel Irhoud, Florisbad, Eliye Springs and Omo Kibish 2 do represent early members of the species, but variation across the African later middle Pleistocene/early Middle Stone Age fossils shows that there was not a simple linear progression towards later sapiens morphology, and there was chronological overlap between different 'archaic' and 'modern' morphs. Even in the late Pleistocene within and outside Africa, we find H. sapiens specimens which are clearly outside the range of Holocene members of the species, showing the complexity of recent human evolution. The impact on species recognition of late Pleistocene gene flow between the lineages of modern humans, Neanderthals and Denisovans is also discussed, and finally, I reconsider the nature of the middle Pleistocene ancestor of these lineages, based on recent morphological and genetic data.This article is part of the themed issue 'Major transitions in human evolution'. © 2016 The Author(s).

  18. Intrinsic Chirality Origination in Carbon Nanotubes.

    Science.gov (United States)

    Pierce, Neal; Chen, Gugang; P Rajukumar, Lakshmy; Chou, Nam Hawn; Koh, Ai Leen; Sinclair, Robert; Maruyama, Shigeo; Terrones, Mauricio; Harutyunyan, Avetik R

    2017-10-24

    Elucidating the origin of carbon nanotube chirality is key for realizing their untapped potential. Currently, prevalent theories suggest that catalyst structure originates chirality via an epitaxial relationship. Here we studied chirality abundances of carbon nanotubes grown on floating liquid Ga droplets, which excludes the influence of catalyst features, and compared them with abundances grown on solid Ru nanoparticles. Results of growth on liquid droplets bolsters the intrinsic preference of carbon nuclei toward certain chiralities. Specifically, the abundance of the (11,1)/χ = 4.31° tube can reach up to 95% relative to (9,4)/χ = 17.48°, although they have exactly the same diameter, (9.156 Å). However, the comparative abundances for the pair, (19,3)/χ = 7.2° and (17,6)/χ = 14.5°, with bigger diameter, (16.405 Å), fluctuate depending on synthesis temperature. The abundances of the same pairs of tubes grown on floating solid polyhedral Ru nanoparticles show completely different trends. Analysis of abundances in relation to nucleation probability, represented by a product of the Zeldovich factor and the deviation interval of a growing nuclei from equilibrium critical size, explain the findings. We suggest that the chirality in the nanotube in general is a result of interplay between intrinsic preference of carbon cluster and induction by catalyst structure. This finding can help to build the comprehensive theory of nanotube growth and offers a prospect for chirality-preferential synthesis of carbon nanotubes by the exploitation of liquid catalyst droplets.

  19. Origins of fluorescence in evolved bacteriophytochromes.

    Science.gov (United States)

    Bhattacharya, Shyamosree; Auldridge, Michele E; Lehtivuori, Heli; Ihalainen, Janne A; Forest, Katrina T

    2014-11-14

    Use of fluorescent proteins to study in vivo processes in mammals requires near-infrared (NIR) biomarkers that exploit the ability of light in this range to penetrate tissue. Bacteriophytochromes (BphPs) are photoreceptors that couple absorbance of NIR light to photoisomerization, protein conformational changes, and signal transduction. BphPs have been engineered to form NIR fluorophores, including IFP1.4, Wi-Phy, and the iRFP series, initially by replacement of Asp-207 by His. This position was suggestive because its main chain carbonyl is within hydrogen-bonding distance to pyrrole ring nitrogens of the biliverdin chromophore, thus potentially functioning as a crucial transient proton sink during photoconversion. To explain the origin of fluorescence in these phytofluors, we solved the crystal structures of IFP1.4 and a comparison non-fluorescent monomeric phytochrome DrCBDmon. Met-186 and Val-288 in IFP1.4 are responsible for the formation of a tightly packed hydrophobic hub around the biliverdin D ring. Met-186 is also largely responsible for the blue-shifted IFP1.4 excitation maximum relative to the parent BphP. The structure of IFP1.4 revealed decreased structural heterogeneity and a contraction of two surface regions as direct consequences of side chain substitutions. Unexpectedly, IFP1.4 with Asp-207 reinstalled (IFPrev) has a higher fluorescence quantum yield (∼9%) than most NIR phytofluors published to date. In agreement, fluorescence lifetime measurements confirm the exceptionally long excited state lifetimes, up to 815 ps, in IFP1.4 and IFPrev. Our research helps delineate the origin of fluorescence in engineered BphPs and will facilitate the wide-spread adoption of phytofluors as biomarkers. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Origins of knowledge: Insights from precocial species

    Directory of Open Access Journals (Sweden)

    Elisabetta eVersace

    2015-12-01

    Full Text Available Behavioural responses are influenced by knowledge acquired during the lifetime of an individual and by predispositions transmitted across generations. Establishing the origin of knowledge and the role of the unlearned component is a challenging task, given that both learned and unlearned knowledge can orient perception, learning, and the encoding of environmental features since the first stages of life. Ethical and practical issues constrain the investigation of unlearned knowledge in altricial species, including human beings. On the contrary, precocial animals can be tested on a wide range of tasks and capabilities immediately after birth and in controlled rearing conditions. Insects and precocial avian species are very convenient models to dissect the knowledge systems that enable young individuals to cope with their environment in the absence of specific previous experience. We present the state of the art of research on the origins of knowledge that come from different models and disciplines. Insects have been mainly used to investigate unlearned sensory preferences and prepared learning mechanisms. The relative simplicity of the neural system and fast life cycle of insects make them ideal models to investigate the neural circuitry and evolutionary dynamics of unlearned traits. Among avian species, chicks of the domestic fowl have been the focus of many studies, and showed to possess unlearned knowledge in the sensory, physical, spatial, numerical and social domains. Solid evidence shows the existence of unlearned knowledge in different domains in several species, from sensory and social preferences to the left-right representation of the mental number line. We show how non-mammalian models of cognition, and in particular precocial species, can shed light into the adaptive value and evolutionary history of unlearned knowledge.

  1. Origins of Knowledge: Insights from Precocial Species.

    Science.gov (United States)

    Versace, Elisabetta; Vallortigara, Giorgio

    2015-01-01

    Behavioral responses are influenced by knowledge acquired during the lifetime of an individual and by predispositions transmitted across generations. Establishing the origin of knowledge and the role of the unlearned component is a challenging task, given that both learned and unlearned knowledge can orient perception, learning, and the encoding of environmental features since the first stages of life. Ethical and practical issues constrain the investigation of unlearned knowledge in altricial species, including human beings. On the contrary, precocial animals can be tested on a wide range of tasks and capabilities immediately after birth and in controlled rearing conditions. Insects and precocial avian species are very convenient models to dissect the knowledge systems that enable young individuals to cope with their environment in the absence of specific previous experience. We present the state of the art of research on the origins of knowledge that comes from different models and disciplines. Insects have been mainly used to investigate unlearned sensory preferences and prepared learning mechanisms. The relative simplicity of the neural system and fast life cycle of insects make them ideal models to investigate the neural circuitry and evolutionary dynamics of unlearned traits. Among avian species, chicks of the domestic fowl have been the focus of many studies, and showed to possess unlearned knowledge in the sensory, physical, spatial, numerical and social domains. Solid evidence shows the existence of unlearned knowledge in different domains in several species, from sensory and social preferences to the left-right representation of the mental number line. We show how non-mammalian models of cognition, and in particular precocial species, can shed light into the adaptive value and evolutionary history of unlearned knowledge.

  2. The origin of malarial parasites in orangutans.

    Directory of Open Access Journals (Sweden)

    M Andreína Pacheco

    Full Text Available BACKGROUND: Recent findings of Plasmodium in African apes have changed our perspectives on the evolution of malarial parasites in hominids. However, phylogenetic analyses of primate malarias are still missing information from Southeast Asian apes. In this study, we report molecular data for a malaria parasite lineage found in orangutans. METHODOLOGY/PRINCIPAL FINDINGS: We screened twenty-four blood samples from Pongo pygmaeus (Kalimantan, Indonesia for Plasmodium parasites by PCR. For all the malaria positive orangutan samples, parasite mitochondrial genomes (mtDNA and two antigens: merozoite surface protein 1 42 kDa (MSP-1(42 and circumsporozoite protein gene (CSP were amplified, cloned, and sequenced. Fifteen orangutans tested positive and yielded 5 distinct mitochondrial haplotypes not previously found. The haplotypes detected exhibited low genetic divergence among them, indicating that they belong to one species. We report phylogenetic analyses using mitochondrial genomes, MSP-1(42 and CSP. We found that the orangutan malaria parasite lineage was part of a monophyletic group that includes all the known non-human primate malaria parasites found in Southeast Asia; specifically, it shares a recent common ancestor with P. inui (a macaque parasite and P. hylobati (a gibbon parasite suggesting that this lineage originated as a result of a host switch. The genetic diversity of MSP-1(42 in orangutans seems to be under negative selection. This result is similar to previous findings in non-human primate malarias closely related to P. vivax. As has been previously observed in the other Plasmodium species found in non-human primates, the CSP shows high polymorphism in the number of repeats. However, it has clearly distinctive motifs from those previously found in other malarial parasites. CONCLUSION: The evidence available from Asian apes indicates that these parasites originated independently from those found in Africa, likely as the result of host

  3. Origins Space Telescope: Breaking the Confusion Limit

    Science.gov (United States)

    Wright, Edward L.; Origins Space Telescope Science and Technology Definition Team

    2018-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies of NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s.OST will have a background-limited sensitivity for a background 27,000 times lower than the Herschel background caused by thermal emission from Herschel's warm telescope. For continuum observations the confusion limit in a diffraction-limited survey can be reached in very short integration times at longer far-infrared wavelengths. But the confusion limit can be pierced for both the nearest and the farthest objects to be observed by OST. For outer the Solar System the targets' motion across the sky will provide a clear signature in surveys repeated after an interval of days to months. This will provide a size-frequency distribution of TNOs that is not biased toward high albedo objects.For the distant Universe the first galaxies and the first metals will provide a third dimension of spectral information that can be measured with a long-slit, medium resolution spectrograph. This will allow 3Dmapping to measure source densities as a function of redshift. The continuum shape associated with sourcesat different redshifts can be derived from correlation analyses of these 3D maps.Fairly large sky areas can be scanned by moving the spacecraft at a constant angular rate perpendicular to the orientation of the long slit of the spectrograph, avoiding the high overhead of step-and-stare surveying with a large space observatory.We welcome you to contact the Science and Technology Definition Team (STDT) with your science needs and ideas by emailing us at ost_info@lists.ipac.caltech.edu

  4. Evolutionary origin of the turtle skull.

    Science.gov (United States)

    Bever, G S; Lyson, Tyler R; Field, Daniel J; Bhullar, Bhart-Anjan S

    2015-09-10

    Transitional fossils informing the origin of turtles are among the most sought-after discoveries in palaeontology. Despite strong genomic evidence indicating that turtles evolved from within the diapsid radiation (which includes all other living reptiles), evidence of the inferred transformation between an ancestral turtle with an open, diapsid skull to the closed, anapsid condition of modern turtles remains elusive. Here we use high-resolution computed tomography and a novel character/taxon matrix to study the skull of Eunotosaurus africanus, a 260-million-year-old fossil reptile from the Karoo Basin of South Africa, whose distinctive postcranial skeleton shares many unique features with the shelled body plan of turtles. Scepticism regarding the status of Eunotosaurus as the earliest stem turtle arises from the possibility that these shell-related features are the products of evolutionary convergence. Our phylogenetic analyses indicate strong cranial support for Eunotosaurus as a critical transitional form in turtle evolution, thus fortifying a 40-million-year extension to the turtle stem and moving the ecological context of its origin back onto land. Furthermore, we find unexpected evidence that Eunotosaurus is a diapsid reptile in the process of becoming secondarily anapsid. This is important because categorizing the skull based on the number of openings in the complex of dermal bone covering the adductor chamber has long held sway in amniote systematics, and still represents a common organizational scheme for teaching the evolutionary history of the group. These discoveries allow us to articulate a detailed and testable hypothesis of fenestral closure along the turtle stem. Our results suggest that Eunotosaurus represents a crucially important link in a chain that will eventually lead to consilience in reptile systematics, paving the way for synthetic studies of amniote evolution and development.

  5. Contradictory or Complementary? Creationist and Evolutionist Explanations of the Origin(s) of Species

    Science.gov (United States)

    Evans, E. Margaret; Lane, Jonathan D.

    2011-01-01

    Almost half of the US public rejects the idea that humans originated via evolution rather than by supernatural design. Moreover, studies demonstrate that even biology teachers have difficulty teaching their students about evolution, often including creationist explanations as well. A typical response to such findings is the argument that greater…

  6. Origin of Evolution versus Origin of Life: A Shift of Paradigm

    Directory of Open Access Journals (Sweden)

    Marc Tessera

    2011-06-01

    Full Text Available The question of the primordial ancestor must be approached through the search for the origin of evolution, not through the search for the origin of life. There is a major issue with the concept of life because it is impossible to define, thus is not a scientific but a metaphysical concept. On the contrary, evolution may be defined by as few as three conditions. These do not necessarily involve biopolymers. However, such an approach must give clues to explain the emergence of distinct lineages to allow Darwinian natural selection. A plausible solution exists within an autotrophic lipidic vesicle-based model that is presented. The model requires the existence of hydrothermal sites such as the Lost City Hydrothermal Field leading to specific constraints. For this reason Mars and Europa may be questioned as possible cradles of evolution. If we replace the search for the origin of life by the one for the origin of evolution our priority first is to find a consensus on the minimal conditions that would allow evolution to emerge and persist anywhere in the universe.

  7. On the origin of cosmic magnetic fields

    Science.gov (United States)

    Kulsrud, Russell M.; Zweibel, Ellen G.

    2008-04-01

    We review the extensive and controversial literature concerning how the cosmic magnetic fields pervading nearly all galaxies and clusters of galaxies actually got started. Some observational evidence supports a hypothesis that the field is already moderately strong at the beginning of the life of a galaxy and its disc. One argument involves the chemical abundance of the light elements Be and B, while a second one is based on the detection of strong magnetic fields in very young high red shift galaxies. Since this problem of initial amplification of cosmic magnetic fields involves important plasma problems it is obvious that one must know the plasma in which the amplification occurs. Most of this review is devoted to this basic problem and for this it is necessary to devote ourselves to reviewing studies that take place in environments in which the plasma properties are most clearly understood. For this reason the authors have chosen to restrict themselves almost completely to studies of dynamos in our Galaxy. It is true that one can get a much better idea of the grand scope of galactic fields in extragalactic systems. However, most mature galaxies share the same dilemma as ours of overcoming important plasma problems. Since the authors are both trained in plasma physics we may be biased in pursuing this approach, but we feel it is justified by the above argument. In addition we feel we can produce a better review by staying close to that which we know best. In addition we have chosen not to consider the saturation problem of the galactic magnetic field since if the original dynamo amplification fails the saturation question does not arise. It is generally accepted that seed fields, whose strength is of order 10-20 G, easily spring up in the era preceding galaxy formation. Several mechanisms have been proposed to amplify these seed magnetic fields to a coherent structure with the microgauss strengths of the currently observed galactic magnetic fields. The standard

  8. On the origin of cosmic magnetic fields

    International Nuclear Information System (INIS)

    Kulsrud, Russell M; Zweibel, Ellen G

    2008-01-01

    We review the extensive and controversial literature concerning how the cosmic magnetic fields pervading nearly all galaxies and clusters of galaxies actually got started. Some observational evidence supports a hypothesis that the field is already moderately strong at the beginning of the life of a galaxy and its disc. One argument involves the chemical abundance of the light elements Be and B, while a second one is based on the detection of strong magnetic fields in very young high red shift galaxies. Since this problem of initial amplification of cosmic magnetic fields involves important plasma problems it is obvious that one must know the plasma in which the amplification occurs. Most of this review is devoted to this basic problem and for this it is necessary to devote ourselves to reviewing studies that take place in environments in which the plasma properties are most clearly understood. For this reason the authors have chosen to restrict themselves almost completely to studies of dynamos in our Galaxy. It is true that one can get a much better idea of the grand scope of galactic fields in extragalactic systems. However, most mature galaxies share the same dilemma as ours of overcoming important plasma problems. Since the authors are both trained in plasma physics we may be biased in pursuing this approach, but we feel it is justified by the above argument. In addition we feel we can produce a better review by staying close to that which we know best. In addition we have chosen not to consider the saturation problem of the galactic magnetic field since if the original dynamo amplification fails the saturation question does not arise. It is generally accepted that seed fields, whose strength is of order 10 -20 G, easily spring up in the era preceding galaxy formation. Several mechanisms have been proposed to amplify these seed magnetic fields to a coherent structure with the microgauss strengths of the currently observed galactic magnetic fields. The standard

  9. The Origin of the Columbia Hills

    Science.gov (United States)

    Rice, J. W.

    2005-12-01

    The Columbia Hills form a rugged ridge complex comprised of 7 peaks spanning some 3.5 km in length and reaching a maximum height of 106 m (Husband Hill) above the plains of Spirit's landing site. As of this writing Spirit has been exploring the Columbia Hills for over 440 sols (since sol 156 on June 11, 2004). Thus far the origin of the Columbia Hills has remained elusive despite detailed analysis of numerous rock and soil targets, including outcrops. The chemical differences among the 6 distinct rock classes attest to the lithologic diversity and geologic complexity of the Hills. Origin of the Columbia Hills Several hypothesis have been put forth to explain the origin of the Columbia Hills: Old eroded partially buried impact crater rim(s), central peak, residual intracrater fill material, volcanic construct, wrinkle ridge, delta and or combinations of the above. Observations that support various aspects of these multiple hypotheses will be discussed. Numerous buried craters are observed on the floor of Gusev lending credence to the idea that the Columbia Hills are the remains of an ancient impact crater rim or possibly a central peak. Morphologic evidence of the rim of Thira crater and the Columbia Hills appears to support this hypothesis. The Aeolis region contains numerous craters that contain layered materials in the absence of any major fluvial systems. This could imply that the Columbia Hills are the remnants of a formerly extensive unit(s). Gusev contains many hills scattered across its floor such as Grissom, White, Chaffee and numerous other buttes and mesas that may be remnants of a former extensive intracrater deposit. Another possibility is that the Columbia Hills are composed of volcanic materials (cinder cones and associated ash and lava flows) derived either locally or from Apollinaris Patera located 300 km to the north. Several depressions are located in the Columbia Hills. These features could be calderas but are most likely impact craters. The most

  10. An original state equation for argillite

    International Nuclear Information System (INIS)

    Cariou, S.; Dormieux, L.; Skoczylas, F.

    2010-01-01

    Document available in extended abstract form only. Argillite is available in large quantities in France and exhibits a very small permeability: that is the reason why it is an excellent candidate for the storage of nuclear waste depositories. This study focuses particularly on argillite from Meuse-Haute-Marne (East of France) located 500 m deep. Following the observation that Biot theory does not permit us to explain some of our experiments, we propose in this contribution to use the tools of continuum micro-mechanics in order to develop a macroscopic state equation that would be consistent with our experimental data. In order to apply homogenization tools to argillite, the first step is to describe the microstructure of this material. Argillite can be modelled as a multi-scale material: - At the macro-scale, argillite looks like a homogenized material. - At the meso-scale, a shale matrix surrounding some inclusions can be distinguished. - At the micro-scale, the shale matrix reveals to be made of a solid phase and of a partially saturated porous network; capillary effects are taken into account at this scale. - At the nano-scale, the solid phase is not homogeneous but is a set of particles that are parallel platelets with an electrolyte in-between; the solid phase is not physically inert with regard to water in the porous network; first, liquid pressure in the electrolyte exists and is equal to liquid pressure in the porous network; then, the unbalance between the ion concentration in-between the platelets building up the solid phase and the ion concentration in the porous network implies an overpressure in the electrolyte. This complex model of argillite leads us though several homogenization steps to an original macroscopic state equation. We propose to compare this state equation with experimental data. Results of a poro-mechanical test run on a partially saturated sample of argillite are shown. One can read that the deformations of the sample are identical

  11. The origin and control of the Camamu barite deposit (BA)

    International Nuclear Information System (INIS)

    Campos, E.G.

    1984-01-01

    Geological and geochemical mechanisms responsible for the origin of the camamu barite deposit (Bahia State) was studied. The marine origin of sulfate is confirmed by the isotopic studies of oxygen delta and sulphur delta. (Author) [pt

  12. 41 CFR 105-62.102 - Authority to originally classify.

    Science.gov (United States)

    2010-07-01

    ... originally classify. (a) Top secret, secret, and confidential. The authority to originally classify information as Top Secret, Secret, or Confidential may be exercised only by the Administrator and is delegable...

  13. Gamma-ray astronomy and cosmic-ray origin theory

    International Nuclear Information System (INIS)

    Ginzburg, V.L.

    1973-01-01

    A theory of the origin of cosmic radiation is discussed in light of the advances made in gamma-ray astronomy. Arguments against metagalactic models for the origin of cosmic rays are emphasized. (U.S.)

  14. The origins of American health libertarianism.

    Science.gov (United States)

    Grossman, Lewis A

    2013-01-01

    This Article examines Americans' enduring demand for freedom of therapeutic choice as a popular constitutional movement originating in the United States' early years. In exploring extrajudicial advocacy for therapeutic choice between the American Revolution and the Civil War, this piece illustrates how multiple concepts of freedom in addition to bodily freedom bolstered the concept of a constitutional right to medical liberty. There is a deep current of belief in the United States that people have a right to choose their preferred treatments without government interference. Modern American history has given rise to movements for access to abortion, life-ending drugs, unapproved cancer treatments, and medical marijuana. Recently, cries of "Death Panels" have routinely been directed against health care reform proposals that citizens believe would limit the products and procedures covered by government health insurance. Some of the most prominent contemporary struggles for health freedom have been waged in court. But other important recent battles for freedom of therapeutic choice have taken place in other forums, from legislative hearings to Food and Drug Administration advisory committee meetings to public demonstrations. This attitude of therapeutic libertarianism is not new. Drawing mainly on primary historical sources, this Article examines arguments in favor of freedom of therapeutic choice voiced in antebellum America in the context of battles against state licensing regimes. After considering some anti-licensing arguments made before independence, it discusses the views and statements of Benjamin Rush, an influential founding father who was also the most prominent American physician of the early national period. The Article then analyzes the Jacksonian-era battle against medical licensing laws waged by the practitioners and supporters of a school of botanical medicine known as Thomsonianism. This triumphant struggle was waged in explicitly constitutional terms

  15. Experiments of the origins of optical activity.

    Science.gov (United States)

    Bonner, W A; Flores, J J

    1975-01-01

    Two recent reports claim that (1) aqueous L-aspartic acid polymerizes faster than D-Asp in the presence of kaolin at 90 degrees, and (2) L-phenylalanine is adsorbed by kaolin more extensively than D-Phe at pH 4(the reverse being true at pH2). The novelty of these observations and their potential significance for the origin of optical activity has prompted us to duplicate these experiments using more sensitive methods. L- and D, L-Asp in 0.01 M solution were incubated with kaolin at 90 degrees for 8 days. Careful examination of the aqueous residues from such experiments failed to demonstrate any preferential polymerization of L-Asp over D-Asp, or indeed any significant gross polymerization of Asp at all. In other experiments 0.001 M solutions of D, L-Phe at pH 6 and pH 2 were stirred with large excesses of kaolin for 24 hr, and the aqueous extracts from these mixtures were examined for gross adsorption using the amino acid analyzer. No significant gross adsorption was noted. We then looked for asymmetric adsorption in the aqueous residues using optical rotatory dispersion, gas chromatography and thin layer chromatography. By none of these analytical criteria could we find any evidence whatsoever for the preferential adsorption of D- versus L-Phe from either pH 6 or pH 2 solutions. Finally, in experiments bearing on the origin of optical activity by parity violation during beta-decay, we have irradiated solid samples of D-, L- and D,L-leucine in a 61700 Ci Sr-90 source at Oak Ridge National Lab. for 1.34 yr (total dose: 4.2 x 10(8) rad). Gas chromatographic examination of the (appropriately derivitized) recovered samples showed that the L-Leu was 16.7% decomposed, the D-Leu 11.4% and theD,L-Leu 13.8% decomposed. The recovered D,L-Leu sample had a gas-chromatographically determined enantiomeric composition of 50.8% D-leu and 49.2% L-Leu. These data, though very close to experimental error, may indicate a slight preferential radiolysis of L-Leu compared to D-Leu by the

  16. WORD ORIGIN HELPS EXPAND LEARNERS’ VOCABULARY A VOCABULARY TEACHING APPROACH

    OpenAIRE

    Li Jing

    2012-01-01

    Word origin (motivation) deals with the connection between name and sense, explaining how a word originated. With the knowledge of how words are originated, learners can grasp a word easier and thus expand their vocabulary more quickly. The introduction to word origin (motivation) by teachers can also help the learners gain interest in the process of learning and learn more about the cultural and historical background of the English-speaking countries. This paper tries to clarify this method ...

  17. The Hsk1(Cdc7) Replication Kinase Regulates Origin Efficiency

    OpenAIRE

    Patel, Prasanta K.; Kommajosyula, Naveen; Rosebrock, Adam; Bensimon, Aaron; Leatherwood, Janet; Bechhoefer, John; Rhind, Nicholas

    2008-01-01

    Origins of DNA replication are generally inefficient, with most firing in fewer than half of cell cycles. However, neither the mechanism nor the importance of the regulation of origin efficiency is clear. In fission yeast, origin firing is stochastic, leading us to hypothesize that origin inefficiency and stochasticity are the result of a diffusible, rate-limiting activator. We show that the Hsk1-Dfp1 replication kinase (the fission yeast Cdc7-Dbf4 homologue) plays such a role. Increasing or ...

  18. Craniofacial anthropometry in newborns of Sikkimese origin.

    Science.gov (United States)

    Sinha, P; Tamang, B K; Chakraborty, S

    2014-06-01

    Head and face dimensions vary according to race and geographical zone. Hereditary factors also greatly affect the size and shape of the head. There are important medical applications of craniofacial data specific to different racial and ethnic groups. Various cranial and facial anthropometric parameters were assessed in singleton, healthy, full-term newborns of Sikkimese origin in a tertiary care hospital in Sikkim, India. The data were then analysed to determine statistically significant differences between sexes. Forty-five newborns were included in the study. Both male and female newborns were observed to be hyperbrachycephalic and hyperleptoprosopic. The only significant difference between the sexes was in commissural length, which was observed to be greater in male newborns. Craniofacial parameters in Sikkimese newborns vary in comparison with those of other newborns from around the world. Larger studies are needed in order to reveal sex-related variations. Similar studies on various racial groups in North-East India are needed to establish standards for populations with East Asian features.

  19. Aux origines de la science moderne

    CERN Document Server

    Rossi, Paolo

    1999-01-01

    Aux origines de la science moderne. " Lorsque l'on aborde l'étude d'une pensée qui n'est plus la nôtre, il est important de chercher à oublier ce que nous savons ou croyons savoir. " Pour appréhender cette période fondatrice que fut la Révolution scientifique du XVIIe siècle en Europe, Paolo Rossi nous replonge dans des atmosphères intellectuelles et des modes de pensée depuis longtemps disparus. Des secrets hermétiques aux calculs mathématiques, de la magie au magnétisme et des cabinets de curiosité aux premières académies des sciences défilent ainsi des notions et des individus qui, remis en toute simplicité dans le contexte de leur époque, retrouvent une épaisseur et un sens nouveaux. Ainsi racontée sous la forme d'une histoire des idées, l'histoire des sciences devient accessible à tous.

  20. Bioavailability enhancers of herbal origin: An overview

    Science.gov (United States)

    Kesarwani, Kritika; Gupta, Rajiv

    2013-01-01

    Recently, the use of herbal medicines has been increased all over the world due to their therapeutic effects and fewer adverse effects as compared to the modern medicines. However, many herbal drugs and herbal extracts despite of their impressive in-vitro findings demonstrates less or negligible in-vivo activity due to their poor lipid solubility or improper molecular size, resulting in poor absorption and hence poor bioavailability. Nowadays with the advancement in the technology, novel drug delivery systems open the door towards the development of enhancing bioavailability of herbal drug delivery systems. For last one decade many novel carriers such as liposomes, microspheres, nanoparticles, transferosomes, ethosomes, lipid based systems etc. have been reported for successful modified delivery of various herbal drugs. Many herbal compounds including quercetin, genistein, naringin, sinomenine, piperine, glycyrrhizin and nitrile glycoside have demonstrated capability to enhance the bioavailability. The objective of this review is to summarize various available novel drug delivery technologies which have been developed for delivery of drugs (herbal), and to achieve better therapeutic response. An attempt has also been made to compile a profile on bioavailability enhancers of herbal origin with the mechanism of action (wherever reported) and studies on improvement in drug bioavailability, exhibited particularly by natural compounds. PMID:23620848

  1. On the physical origin of galactic conformity

    Science.gov (United States)

    Hearin, Andrew P.; Behroozi, Peter S.; van den Bosch, Frank C.

    2016-09-01

    Correlations between the star formation rates (SFRs) of nearby galaxies (so-called galactic conformity) have been observed for projected separations up to 4 Mpc, an effect not predicted by current semi-analytic models. We investigate correlations between the mass accretion rates (dMvir/dt) of nearby haloes as a potential physical origin for this effect. We find that pairs of host haloes `know about' each others' assembly histories even when their present-day separation is greater than thirty times the virial radius of either halo. These distances are far too large for direct interaction between the haloes to explain the correlation in their dMvir/dt. Instead, halo pairs at these distances reside in the same large-scale tidal environment, which regulates dMvir/dt for both haloes. Larger haloes are less affected by external forces, which naturally gives rise to a mass dependence of the halo conformity signal. SDSS measurements of galactic conformity exhibit a qualitatively similar dependence on stellar mass, including how the signal varies with distance. Based on the expectation that halo accretion and galaxy SFR are correlated, we predict the scale-, mass- and redshift-dependence of large-scale galactic conformity, finding that the signal should drop to undetectable levels by z ≳ 1. These predictions are testable with current surveys to z ˜ 1; confirmation would establish a strong correlation between dark matter halo accretion rate and central galaxy SFR.

  2. Origins and Impacts of New Mammalian Exons

    Directory of Open Access Journals (Sweden)

    Jason J. Merkin

    2015-03-01

    Full Text Available Mammalian genes are composed of exons, but the evolutionary origins and functions of new internal exons are poorly understood. Here, we analyzed patterns of exon gain using deep cDNA sequencing data from five mammals and one bird, identifying thousands of species- and lineage-specific exons. Most new exons derived from unique rather than repetitive intronic sequence. Unlike exons conserved across mammals, species-specific internal exons were mostly located in 5′ UTRs and alternatively spliced. They were associated with upstream intronic deletions, increased nucleosome occupancy, and RNA polymerase II pausing. Genes containing new internal exons had increased gene expression, but only in tissues in which the exon was included. Increased expression correlated with the level of exon inclusion, promoter proximity, and signatures of cotranscriptional splicing. Altogether, these findings suggest that increased splicing at the 5′ ends of genes enhances expression and that changes in 5′ end splicing alter gene expression between tissues and between species.

  3. The Origin of Sequential Chromospheric Brightenings

    Science.gov (United States)

    Kirk, M. S.; Balasubramaniam, K. S.; Jackiewicz, J.; Gilbert, H. R.

    2017-06-01

    Sequential chromospheric brightenings (SCBs) are often observed in the immediate vicinity of erupting flares and are associated with coronal mass ejections. Since their initial discovery in 2005, there have been several subsequent investigations of SCBs. These studies have used differing detection and analysis techniques, making it difficult to compare results between studies. This work employs the automated detection algorithm of Kirk et al. (Solar Phys. 283, 97, 2013) to extract the physical characteristics of SCBs in 11 flares of varying size and intensity. We demonstrate that the magnetic substructure within the SCB appears to have a significantly smaller area than the corresponding Hα emission. We conclude that SCBs originate in the lower corona around 0.1 R_{⊙} above the photosphere, propagate away from the flare center at speeds of 35 - 85 km s^{-1}, and have peak photosphere magnetic intensities of 148±2.9 G. In light of these measurements, we infer SCBs to be distinctive chromospheric signatures of erupting coronal mass ejections.

  4. Power, Ethnic Origin, and Sexual Objectification

    Directory of Open Access Journals (Sweden)

    Ciro Civile

    2016-04-01

    Full Text Available In this study, we investigated the effects of primed power on sexual objectification of Caucasian and Asian men and women. As in previous studies, sexual objectification was assessed using an inversion paradigm with face–body compound stimuli. Previous work has shown that participants primed to power do not show the typical drop in recognition performance for inverted face–body compound stimuli, suggesting that they process these stimuli in terms of their individual features, in a manner akin to objects, and quite different from the way in which faces and bodies are normally processed (i.e., configurally. Caucasian male and female participants were primed to high or neutral-power before engaging in an old/new recognition task involving sexualized face–body compound images of Caucasian and Asian men and women. Participants primed to high-power showed a decreased inversion effect for Caucasian models of the opposite gender, but not for Asian models. Thus, power exerts different effects on this specific type of social perception, depending on the ethnic origin of the target. We discuss our results in the context of the extant literature on power and with reference to media stereotyping of Caucasians and Asians.

  5. The origin of the 1883 Krakatau tsunamis

    Science.gov (United States)

    Francis, P. W.

    1985-01-01

    Three hypotheses proposed to explain possible causes of the Aug. 27, 1883 Krakatau tsunamis were analyzed: (1) large-scale collapse of the northern part of Krakatau island (Verbeek, 1884), (2) submarine explosion (Yokoyama, 1981), and (3) emplacement of pyroclastic flows (Latter, 1981). A study of timings of the air and sea waves between Krakatau and Batavia, showing that no precise sea wave travel times can be obtained, and a study of the tide and pressure gage records made on August 27, indicating that the air and sea waves were propagated from the focus of eruption on Krakatau island, suggest that neither hypothesis 2 or 3 are sufficiently substantiated. In addition, the event that caused the major air and sea wave was preceded (by 40 min) by a similar, smaller event which generated the second largest tsunami and an air wave. It is concluded that the most likely mechanism for the eruption is a Mt. St. Helens scenario, close to the hypothesis of Verbeek, in which collapse of part of the original volcanic edifice propagated a major explosion.

  6. The Origin of Cell Boundaries and Metabolism

    Science.gov (United States)

    Radu, Popa

    The wide gap between the properties of non-living phenomena and the simplest living forms cannot be explained without some intermediate stages (Ruiz-Mirazo et al. 1999). Although some achievements of life suggest that a continuum might have existed between non-life and life (Browning 1869, Hazen 2001), many features of life appear to have emerged in a stepwise way. The addition of a boundary capable of separating the interior from the exterior is one of those achievements of life showing a pronounced stepwise (phase transition) character. Many authors believe that the formation of phase-separated systems (PSSs) was necessarily one of the earliest if not the absolute precondition for the origin of the living state (Oparin 1938, 1968, Oró and Lazcano 1990, Lyubarev and Kurganov 1995, Turian 1999). This seclusion from the external environment was given a variety of names such as compartmentalization, cellularization, territorial separation, segregation or encapsulation (Oparin 1924, 1968, Haldane 1929, Fox 1964, Edwards and Peng 1998, Edwards et al. 1998, Deamer 1998, Arrhenius 2002, Guimarães 2002). A variety of names was also used to describe the earliest PSSs, such as coacervates (Oparin 1921, 1968), bioids (Decker 1973), proteinoid microspheres (Fox and Dose 1977), aggregates (Kaplan 1978), marigranules, marisomes (Yanagawa and Egami 1980), liposomes (Deamer 1986, Schmidli et al. 1991), jee-wanu' meaning life particles' in Sanskrit (Badahur and Ranganayaki 1970), probotryoids (Russell et al. 1994), microvesicles, microspheres (Turian 1999) or droplets (Dyson 1997).

  7. Soap film vibration: origin of the dissipation.

    Science.gov (United States)

    Acharige, Sébastien Kosgodagan; Elias, Florence; Derec, Caroline

    2014-11-07

    We investigate the complex dispersion relationship of a transverse antisymmetric wave on a horizontal soap film. Experimentally, the complex wave number k at a fixed forcing frequency is determined by measuring the vibrating amplitude of the soap film: the wavelength (linked to the real part of k) is determined by the spatial variation of the amplitude; the decay length (linked to the imaginary part of k) is determined by analyzing the resonance curves of the vibrating wave as a function of frequency. Theoretically, we compute the complex dispersion relationship taking into account the physical properties of the bulk liquid and gas phase, and of the gas-liquid interfaces. The comparison between the computation (developed to the leading order under our experimental conditions) and the experimental results confirms that the phase velocity is fixed by the interplay between surface tension, and liquid and air inertia, as reported in previous studies. Moreover, we show that the attenuation of the transverse antisymmetric wave originates from the viscous dissipation in the gas phase surrounding the liquid film. This result is an important step in understanding the propagation of an acoustic wave in liquid foam, using a bottom-up approach.

  8. Origin of structure in the Universe

    International Nuclear Information System (INIS)

    Halliwell, J.J.; Hawking, S.W.

    1985-01-01

    It is assumed that the Universe is in the quantum state defined by a path integral over compact four-metrics. This can be regarded as a boundary condition for the wave function of the Universe on superspace, the space of all three-metrics and matter field configurations on a three-surface. We extend previous work on finite-dimensional approximations to superspace to the full infinite-dimensional space. We treat the two homogeneous and isotropic degrees of freedom exactly and the others to second order. We justify this approximation by showing that the inhomogeneous or anisotropic modes start off in their ground state. We derive time-dependent Schroedinger equations for each mode. The modes remain in their ground state until their wavelength exceeds the horizon size in the period of exponential expansion. The ground-state fluctuations are then amplified by the subsequent expansion and the modes reenter the horizon in the matter- or radiation-dominated era in a highly excited state. We obtain a scale-free spectrum of density perturbations which could account for the origin of galaxies and all other structure in the Universe. The fluctuations would be compatible with observations of the microwave background if the mass of the scalar field that drives the inflation is 10 14 GeV or less

  9. Lung Lesions During Fever of Unknown Origin.

    Science.gov (United States)

    Krupa, Renata; Zielonka, Tadeusz M; Hadzik-Blaszczyk, Malgorzata; Wardyn, Kazimierz A; Zycinska, Katarzyna

    2017-01-01

    Fever of unknown origin (FUO) remains one of the most difficult diagnostic challenges. The causes of FUO can be various diseases located in different organs. The aim of the study was to determine the prevalence and nature of pulmonary lesions during FUO. One hundred and sixty one patients with FUO participated in this prospective study. We performed a detailed comprehensive history, physical examination, and a wide spectrum of tests. The most common causes of FUO were infections (39%), autoimmune conditions (28%), and neoplasms (17%). Lung lesions were found in 30% of patients. In this group 35% were infections, 30% autoimmune diseases, and 4% cancer. Among patients with respiratory infections, there were cases of tuberculosis, atypical pneumonia, lung abscess, and bronchiectases. Autoimmune pulmonary lesions were observed during vasculitis and systemic lupus. The causes of FUO in the group of patients with lung lesions were also pulmonary embolism, sarcoidosis, and pulmonary fibrosis. Chest CT played an important role in the diagnosis of the causes of FUO with pulmonary manifestations. Pulmonary lesions are a common cause of FUO. Most FUO with pulmonary lesions are recognized during infections and autoimmune diseases. An important part of diagnosing FUO is a detailed evaluation of the respiratory system.

  10. The Origin of the Variola Virus

    Directory of Open Access Journals (Sweden)

    Igor V. Babkin

    2015-03-01

    Full Text Available The question of the origin of smallpox, one of the major menaces to humankind, is a constant concern for the scientific community. Smallpox is caused by the agent referred to as the variola virus (VARV, which belongs to the genus Orthopoxvirus. In the last century, smallpox was declared eradicated from the human community; however, the mechanisms responsible for the emergence of new dangerous pathogens have yet to be unraveled. Evolutionary analyses of the molecular biological genomic data of various orthopoxviruses, involving a wide range of epidemiological and historical information about smallpox, have made it possible to date the emergence of VARV. Comparisons of the VARV genome to the genomes of the most closely related orthopoxviruses and the examination of the distribution their natural hosts’ ranges suggest that VARV emerged 3000 to 4000 years ago in the east of the African continent. The VARV evolution rate has been estimated to be approximately 2 × 10−6 substitutions/site/year for the central conserved genomic region and 4 × 10−6 substitutions/site/year for the synonymous substitutions in the genome. Presumably, the introduction of camels to Africa and the concurrent changes to the climate were the particular factors that triggered the divergent evolution of a cowpox-like ancestral virus and thereby led to the emergence of VARV.

  11. Multiple origins for phenylketonuria in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Eisensmith, R.C.; Okano, Y.; Dasovich, M.; Wang, T.; Woo, S.L.C. (Baylor College of Medicine, Houston, TX (United States)); Guettler, F.; Lou, H.; Guldberg, P. (John F. Kennedy Inst., Glostrup (Denmark)); Lichter-Konecki, U.; Konecki, D.S. (Universitaets-Kinderklinik, Heidelberg (Germany)); Svensson, E.; Hagenfeldt, L. (Huddinge University Hospital (Sweden)); Rey, F.; Munnich, A.; Lyonnet, S. (Hopital des Enfants-Malades, Paris (France)); Cockburn, F.; Connor, J.M. (Univ. of Glasgow (United Kingdom)); Pembrey, M.E.; Smith, I. (Univ. of London (United Kingdom)); Gitzelmann, R.; Steinmann, B. (Universitaets-Kinderklinik, Zuerich (Switzerland)); Apold, J.; Eiken, H.G. (Universitet i Bergen (Norway)); Giovannini, M.; Riva, E.; Longhi, R. (Universita Degli Studi Di Milano, Milan (Italy)); Romano, C.; Cerone, R. (Universita Di Genova, Genoa (Italy)); Naughten, E.R.; Mullins, C.; Cahalane, S. (Children' s Hospital, Dublin (Ireland)); Oezalp, I. (Hacettepe Univ., Ankara (Turkey))

    1992-12-01

    Phenylketonuria (PKU), a disorder of amino acid metabolism prevalent among Caucasians and other ethnic groups, is caused primarily by a deficiency of the hepatic enzyme phenylalanine hydroxylase (PAH). PKU is a highly heterogeneous disorder, with more than 60 molecular lesions identified in the PAH gene. The haplotype associations, relative frequencies, and distributions of five prevalent PAH mutations (R158Q, R261Q, IVS10nt546, R408W, and IVS12nt1) were established in a comprehensive European sample population and subsequently were examined to determine the potential roles of several genetic mechanisms in explaining the present distribution of the major PKU alleles. Each of these five mutations was strongly associated with only one of the more than 70 chromosomal haplotypes defined by eight RFLPs in or near the PAH gene. These findings suggest that each of these mutations arose through a single founding event that occurred within time periods ranging from several hundred to several thousand years ago. From the significant differences observed in the relative frequencies and distributions of these five alleles throughout Europe, four of these putative founding events could be localized to specific ethnic subgroups. Together, these data suggest that there were multiple, geographically and ethnically distinct origins for PKU within the European population. 63 refs., 2 figs., 3 tabs.

  12. [Language and reality: the origin of man].

    Science.gov (United States)

    Maturana, H

    1989-07-01

    The author proposes: 1. That a lineage of living systems is constituted by the reproductive conservation of a manner of living under the form of an ontogenic phenotype. 2. That language is a manner of living in recurrent consensual coordinations of consensual coordinations of actions. 3. That the human manner of living entails among other things, a braiding of languaging and emotioning that we call conversation. 4. That human beings arise in the history of bipedal primates with the origin of language, and the constitution of a lineage defined by the conservation of an ontogenic phenotype that includes conversations as part of it. 5. That the magnitude of the involvement of the brain and anatomy of the larynx and face in speech as our main manner of languaging indicate that language cannot have arisen later than two to three millions year ago. 6. That rationally pertains to the operational coherences of languaging and that different rational domains are constituted by different basic notions that are accepted a priori. That is, on preference. 7. That responsibility and freedom are a function of our awareness of the participation of our emotions (preferences) in the constitution of the rational domains in which we operate.

  13. Origin and evolution of chromosomal sperm proteins.

    Science.gov (United States)

    Eirín-López, José M; Ausió, Juan

    2009-10-01

    In the eukaryotic cell, DNA compaction is achieved through its interaction with histones, constituting a nucleoprotein complex called chromatin. During metazoan evolution, the different structural and functional constraints imposed on the somatic and germinal cell lines led to a unique process of specialization of the sperm nuclear basic proteins (SNBPs) associated with chromatin in male germ cells. SNBPs encompass a heterogeneous group of proteins which, since their discovery in the nineteenth century, have been studied extensively in different organisms. However, the origin and controversial mechanisms driving the evolution of this group of proteins has only recently started to be understood. Here, we analyze in detail the histone hypothesis for the vertical parallel evolution of SNBPs, involving a "vertical" transition from a histone to a protamine-like and finally protamine types (H --> PL --> P), the last one of which is present in the sperm of organisms at the uppermost tips of the phylogenetic tree. In particular, the common ancestry shared by the protamine-like (PL)- and protamine (P)-types with histone H1 is discussed within the context of the diverse structural and functional constraints acting upon these proteins during bilaterian evolution.

  14. The origin of mouth-exhaled ammonia.

    Science.gov (United States)

    Chen, W; Metsälä, M; Vaittinen, O; Halonen, L

    2014-09-01

    It is known that the oral cavity is a production site for mouth-exhaled NH3. However, the mechanism of NH3 production in the oral cavity has been unclear. Since bacterial urease in the oral cavity has been found to produce ammonia from oral fluid urea, we hypothesize that oral fluid urea is the origin of mouth-exhaled NH3. Our results show that under certain conditions a strong correlation exists between oral fluid urea and oral fluid ammonia (NH4(+)+NH3) (rs = 0.77, p oral fluid NH3 and mouth-exhaled NH3 (rs = 0.81, p oral fluid pH. Bacterial urease catalyses the hydrolysis of oral fluid urea to ammonia (NH4(+)+NH3). Oral fluid ammonia (NH4(+)+NH3) and pH determine the concentration of oral fluid NH3, which evaporates from oral fluid into gas phase and turns to mouth-exhaled NH3.

  15. The origin and evolution of phototropins

    Directory of Open Access Journals (Sweden)

    Fay-Wei eLi

    2015-08-01

    Full Text Available Plant phototropism, the ability to bend toward or away from light, is predominantly controlled by blue-light photoreceptors, the phototropins. Although phototropins have been well-characterized in Arabidopsis thaliana, their evolutionary history is largely unknown. In this study, we complete an in-depth survey of phototropin homologs across land plants and algae using newly available transcriptomic and genomic data. We show that phototropins originated in an ancestor of Viridiplantae (land plants + green algae. Phototropins repeatedly underwent independent duplications in most major land-plant lineages (mosses, lycophytes, ferns, and seed plants, but remained single-copy genes in liverworts and hornworts—an evolutionary pattern shared with another family of photoreceptors, the phytochromes. Following each major duplication event, the phototropins differentiated in parallel, resulting in two specialized, yet partially overlapping, functional forms that primarily mediate either low- or high-light responses. Our detailed phylogeny enables us to not only uncover new phototropin lineages, but also link our understanding of phototropin function in Arabidopsis with what is known in Adiantum and Physcomitrella (the major model organisms outside of flowering plants. We propose that the convergent functional divergences of phototropin paralogs likely contributed to the success of plants through time in adapting to habitats with diverse and heterogeneous light conditions.

  16. Dual origin of pairing in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Idini, A. [University of Jyvaskyla, Department of Physics (Finland); Potel, G. [Michigan State University, National Superconducting Cyclotron Laboratory (United States); Barranco, F. [Escuela Superior de Ingenieros, Universidad de Sevilla, Departamento de Fìsica Aplicada III (Spain); Vigezzi, E., E-mail: enrico.vigezzi@mi.infn.it [INFN Sezione di Milano (Italy); Broglia, R. A. [Università di Milano, Dipartimento di Fisica (Italy)

    2016-11-15

    The pairing correlations of the nucleus {sup 120}Sn are calculated by solving the Nambu–Gor’kov equations, including medium polarization effects resulting from the interweaving of quasiparticles, spin and density vibrations, taking into account, within the framework of nuclear field theory (NFT), processes leading to self-energy and vertex corrections and to the induced pairing interaction. From these results one can not only demonstrate the inevitability of the dual origin of pairing in nuclei, but also extract information which can be used at profit to quantitatively disentangle the contributions to the pairing gap Δ arising from the bare and from the induced pairing interaction. The first is the strong {sup 1}S{sub 0} short-range NN potential resulting from meson exchange between nucleons moving in time reversal states within an energy range of hundreds of MeV from the Fermi energy. The second results from the exchange of vibrational modes between nucleons moving within few MeV from the Fermi energy. Short- (v{sub p}{sup bare}) and long-range (v{sub p}{sup ind}) pairing interactions contribute essentially equally to nuclear Cooper pair stability. That is to the breaking of gauge invariance in open-shell superfluid nuclei and thus to the order parameter, namely to the ground state expectation value of the pair creation operator. In other words, to the emergent property of generalized rigidity in gauge space, and associated rotational bands and Cooper pair tunneling between members of these bands.

  17. Natural Origin Materials for Osteochondral Tissue Engineering.

    Science.gov (United States)

    Bonani, Walter; Singhatanadgige, Weerasak; Pornanong, Aramwit; Motta, Antonella

    2018-01-01

    Materials selection is a critical aspect for the production of scaffolds for osteochondral tissue engineering. Synthetic materials are the result of man-made operations and have been investigated for a variety of tissue engineering applications. Instead, the products of physiological processes and the metabolic activity of living organisms are identified as natural materials. Over the recent decades, a number of natural materials, namely, biopolymers and bioceramics, have been proposed as the main constituent of osteochondral scaffolds, but also as cell carriers and signaling molecules. Overall, natural materials have been investigated both in the bone and in the cartilage compartment, sometimes alone, but often in combination with other biopolymers or synthetic materials. Biopolymers and bioceramics possess unique advantages over their synthetic counterparts due similarity with natural extracellular matrix, the presence of cell recognition sites and tunable chemistry. However, the characteristics of natural origin materials can vary considerably depending on the specific source and extraction process. A deeper understanding of the relationship between material variability and biological activity and the definition of standardized manufacturing procedures will be crucial for the future of natural materials in tissue engineering.

  18. Solar origins of coronal mass ejections

    Science.gov (United States)

    Kahler, Stephen

    1987-01-01

    The large scale properties of coronal mass ejections (CMEs), such as morphology, leading edge speed, and angular width and position, have been cataloged for many events observed with coronagraphs on the Skylab, P-78, and SMM spacecraft. While considerable study has been devoted to the characteristics of the SMEs, their solar origins are still only poorly understood. Recent observational work has involved statistical associations of CMEs with flares and filament eruptions, and some evidence exists that the flare and eruptive-filament associated CMEs define two classes of events, with the former being generally more energetic. Nevertheless, it is found that eruptive-filament CMEs can at times be very energetic, giving rise to interplanetary shocks and energetic particle events. The size of the impulsive phase in a flare-associated CME seems to play no significant role in the size or speed of the CME, but the angular sizes of CMEs may correlate with the scale sizes of the 1-8 angstrom x-ray flares. At the present time, He 10830 angstrom observations should be useful in studying the late development of double-ribbon flares and transient coronal holes to yield insights into the CME aftermath. The recently available white-light synoptic maps may also prove fruitful in defining the coronal conditions giving rise to CMEs.

  19. On the evolutionary origins of equity.

    Directory of Open Access Journals (Sweden)

    Stéphane Debove

    Full Text Available Equity, defined as reward according to contribution, is considered a central aspect of human fairness in both philosophical debates and scientific research. Despite large amounts of research on the evolutionary origins of fairness, the evolutionary rationale behind equity is still unknown. Here, we investigate how equity can be understood in the context of the cooperative environment in which humans evolved. We model a population of individuals who cooperate to produce and divide a resource, and choose their cooperative partners based on how they are willing to divide the resource. Agent-based simulations, an analytical model, and extended simulations using neural networks provide converging evidence that equity is the best evolutionary strategy in such an environment: individuals maximize their fitness by dividing benefits in proportion to their own and their partners' relative contribution. The need to be chosen as a cooperative partner thus creates a selection pressure strong enough to explain the evolution of preferences for equity. We discuss the limitations of our model, the discrepancies between its predictions and empirical data, and how interindividual and intercultural variability fit within this framework.

  20. The origin of multicellularity in cyanobacteria

    Science.gov (United States)

    2011-01-01

    Background Cyanobacteria are one of the oldest and morphologically most diverse prokaryotic phyla on our planet. The early development of an oxygen-containing atmosphere approximately 2.45 - 2.22 billion years ago is attributed to the photosynthetic activity of cyanobacteria. Furthermore, they are one of the few prokaryotic phyla where multicellularity has evolved. Understanding when and how multicellularity evolved in these ancient organisms would provide fundamental information on the early history of life and further our knowledge of complex life forms. Results We conducted and compared phylogenetic analyses of 16S rDNA sequences from a large sample of taxa representing the morphological and genetic diversity of cyanobacteria. We reconstructed ancestral character states on 10,000 phylogenetic trees. The results suggest that the majority of extant cyanobacteria descend from multicellular ancestors. Reversals to unicellularity occurred at least 5 times. Multicellularity was established again at least once within a single-celled clade. Comparison to the fossil record supports an early origin of multicellularity, possibly as early as the "Great Oxygenation Event" that occurred 2.45 - 2.22 billion years ago. Conclusions The results indicate that a multicellular morphotype evolved early in the cyanobacterial lineage and was regained at least once after a previous loss. Most of the morphological diversity exhibited in cyanobacteria today —including the majority of single-celled species— arose from ancient multicellular lineages. Multicellularity could have conferred a considerable advantage for exploring new niches and hence facilitated the diversification of new lineages. PMID:21320320