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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.

    Directory of Open Access Journals (Sweden)

    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. Dissecting and Exploiting Nonribosomal Peptide Synthetases

    Institute of Scientific and Technical Information of China (English)

    Qing-Tao SHEN; Xiu-Lan CHEN; Cai-Yun SUN; Yu-Zhong ZHANG

    2004-01-01

    A large number of therapeutically useful cyclic and linear peptides of bacteria or fungal origin are synthesized via a template-directed, nucleic-acid-independent nonribosomal mechanism. This process is carried out by mega-enzymes called nonribosomal peptide synthetases (NRPSs). NRPSs contain repeated coordinated groups of active sites called modules, and each module is composed of several domains with different catalytic activities. The familiarity to these domains lays base for the future genetic engineering of NRPSs to generate entirely "unnature" Products. The details about NRPSs domain structures and the exploitation of NRPSs are described in this review.

  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. Enhancing Nonribosomal Peptide Biosynthesis in Filamentous Fungi.

    Science.gov (United States)

    Soukup, Alexandra A; Keller, Nancy P; Wiemann, Philipp

    2016-01-01

    Filamentous fungi are historically known as rich sources for production of biologically active natural products, so-called secondary metabolites. One particularly pharmaceutically relevant chemical group of secondary metabolites is the nonribosomal peptides synthesized by nonribosomal peptide synthetases (NRPSs). As most of the fungal NRPS gene clusters leading to production of the desired molecules are not expressed under laboratory conditions, efforts to overcome this impediment are crucial to unlock the full chemical potential of each fungal species. One way to activate these silent clusters is by overexpressing and deleting global regulators of secondary metabolism. The conserved fungal-specific regulator of secondary metabolism, LaeA, was shown to be a valuable target for sleuthing of novel gene clusters and metabolites. Additionally, modulation of chromatin structures by either chemical or genetic manipulation has been shown to activate cryptic metabolites. Furthermore, NRPS-derived molecules seem to be affected by cross talk between the specific gene clusters and some of these metabolites have a tissue- or developmental-specific regulation. This chapter summarizes how this knowledge of different tiers of regulation can be combined to increase production of NRPS-derived metabolites in fungal species.

  5. Enhancing Nonribosomal Peptide Biosynthesis in Filamentous Fungi

    Science.gov (United States)

    Soukup, Alexandra A.; Keller, Nancy P.; Wiemann, Philipp

    2016-01-01

    Filamentous fungi are historically known as rich sources for production of biologically active natural products, so-called secondary metabolites. One particularly pharmaceutically relevant chemical group of secondary metabolites is the nonribosomal peptides synthesized by nonribosomal peptide synthetases (NRPSs). As most of the fungal NRPS gene clusters leading to production of the desired molecules are not expressed under laboratory conditions, efforts to overcome this impediment are crucial to unlock the full chemical potential of each fungal species. One way to activate these silent clusters is by overexpressing and deleting global regulators of secondary metabolism. The conserved fungal-specific regulator of secondary metabolism, LaeA, was shown to be a valuable target for sleuthing of novel gene clusters and metabolites. Additionally, modulation of chromatin structures by either chemical or genetic manipulation has been shown to activate cryptic metabolites. Furthermore, NRPS-derived molecules seem to be affected by cross talk between the specific gene clusters and some of these metabolites have a tissue- or developmental-specific regulation. This chapter summarizes how this knowledge of different tiers of regulation can be combined to increase production of NRPS-derived metabolites in fungal species. PMID:26831707

  6. Structural pattern matching of nonribosomal peptides

    Directory of Open Access Journals (Sweden)

    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.

  7. Recent advances in engineering nonribosomal peptide assembly lines.

    Science.gov (United States)

    Winn, M; Fyans, J K; Zhuo, Y; Micklefield, J

    2016-02-01

    Nonribosomal peptides are amongst the most widespread and structurally diverse secondary metabolites in nature with many possessing bioactivity that can be exploited for therapeutic applications. Due to the major challenges associated with total- and semi-synthesis, bioengineering approaches have been developed to increase yields and generate modified peptides with improved physicochemical properties or altered bioactivity. Here we review the major advances that have been made over the last decade in engineering the biosynthesis of nonribosomal peptides. Structural diversity has been introduced by the modification of enzymes required for the supply of precursors or by heterologous expression of tailoring enzymes. The modularity of nonribosomal peptide synthetase (NRPS) assembly lines further supports module or domain swapping methodologies to achieve changes in the amino acid sequence of nonribosomal peptides. We also review the new synthetic biology technologies promising to speed up the process, enabling the creation and optimisation of many more assembly lines for heterologous expression, offering new opportunities for engineering the biosynthesis of novel nonribosomal peptides.

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

    Science.gov (United States)

    Chen, Yunqiu; Ntai, Ioanna; Ju, Kou-San; Unger, Michelle; Zamdborg, Leonid; Robinson, Sarah J; Doroghazi, James R; Labeda, David P; Metcalf, William W; Kelleher, Neil L

    2012-01-01

    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 molecule products of these gene clusters still unknown. Here, we employed a "protein-first" method called PrISM (Proteomic Investigation of Secondary Metabolism) to screen 26 unsequenced actinomycetes using mass spectrometry-based proteomics for the targeted detection of expressed nonribosomal peptide synthetases or polyketide synthases. Improvements to the original PrISM screening approach (Nat. Biotechnol. 2009, 27, 951-956), for example, improved de novo peptide sequencing, have enabled the discovery of 10 NRPS/PKS gene clusters from 6 strains. Taking advantage of the concurrence of biosynthetic enzymes and the secondary metabolites they generate, two natural products were associated with their previously "orphan" gene clusters. This work has demonstrated the feasibility of a proteomics-based strategy for use in screening for NRP/PK production in actinomycetes (often >8 Mbp, high GC genomes) versus the bacilli (2-4 Mbp genomes) used previously.

  9. 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...

  10. 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...

  11. Portability of oxidase domains in nonribosomal peptide synthetase modules.

    Science.gov (United States)

    Schneider, Tanya L; Walsh, Christopher T

    2004-12-21

    Oxazole and thiazole rings are present in numerous nonribosomal peptide natural products. Oxidase domains are responsible for catalyzing the oxidation of thiazolines and oxazolines to yield fully aromatic heterocycles. Unlike most domains, the placement of oxidase domains within assembly line modules varies. Noting this tolerance, we investigated the portability of an oxidase domain to a heterologous assembly line. The epimerase domain of PchE, involved in pyochelin biosynthesis, was replaced with the oxidase domain from MtaD, involved in myxothiazol biosynthesis. The chimeric module was expressed in soluble form as a flavin mononucleotide-containing flavoprotein. The functionality of the inserted oxidase domain was assayed within PchE and in transfer of the growing siderophore acyl chain from PchE to the next downstream module. While pyochelin-like product release was not observed downstream, the robust activity of the transplanted oxidase domain and the ability of the chimeric module to produce an advanced intermediate bound to the synthetase underscore the possibility of future engineering within nonribosomal peptide synthetase pathways using oxidase domains.

  12. Anthranilate-activating modules from fungal nonribosomal peptide assembly lines.

    Science.gov (United States)

    Ames, Brian D; Walsh, Christopher T

    2010-04-20

    Fungal natural products containing benzodiazepinone- and quinazolinone-fused ring systems can be assembled by nonribosomal peptide synthetases (NRPS) using the conformationally restricted beta-amino acid anthranilate as one of the key building blocks. We validated that the first module of the acetylaszonalenin synthetase of Neosartorya fischeri NRRL 181 activates anthranilate to anthranilyl-AMP. With this as a starting point, we then used bioinformatic predictions about fungal adenylation domain selectivities to identify and confirm an anthranilate-activating module in the fumiquinazoline A producer Aspergillus fumigatus Af293 as well as a second anthranilate-activating NRPS in N. fischeri. This establishes an anthranilate adenylation domain code for fungal NRPS and should facilitate detection and cloning of gene clusters for benzodiazepine- and quinazoline-containing polycyclic alkaloids with a wide range of biological activities.

  13. Structural insights into nonribosomal peptide enzymatic assembly lines.

    Science.gov (United States)

    Koglin, Alexander; Walsh, Christopher T

    2009-08-01

    Nonribosomal peptides have a variety of medicinal activities including activity as antibiotics, antitumor drugs, immunosuppressives, and toxins. Their biosynthesis on multimodular assembly lines as a series of covalently tethered thioesters, in turn covalently attached on pantetheinyl arms on carrier protein way stations, reflects similar chemical logic and protein machinery to fatty acid and polyketide biosynthesis. While structural information on excised or isolated catalytic adenylation (A), condensation (C), peptidyl carrier protein (PCP) and thioesterase (TE) domains had been gathered over the past decade, little was known about how the NRPS catalytic and carrier domains interact with each other both within and across elongation or termination modules. This Highlight reviews recent breakthrough achievements in both X-ray and NMR spectroscopic studies that illuminate the architecture of NRPS PCP domains, PCP-containing didomain-fragments and of a full termination module (C-A-PCP-TE).

  14. The Role of a Nonribosomal Peptide Synthetase in l-Lysine Lactamization During Capuramycin Biosynthesis.

    Science.gov (United States)

    Liu, Xiaodong; Jin, Yuanyuan; Cui, Zheng; Nonaka, Koichi; Baba, Satoshi; Funabashi, Masanori; Yang, Zhaoyong; Van Lanen, Steven G

    2016-05-03

    Capuramycins are one of several known classes of natural products that contain an l-Lys-derived l-α-amino-ɛ-caprolactam (l-ACL) unit. The α-amino group of l-ACL in a capuramycin is linked to an unsaturated hexuronic acid component through an amide bond that was previously shown to originate by an ATP-independent enzymatic route. With the aid of a combined in vivo and in vitro approach, a predicted tridomain nonribosomal peptide synthetase CapU is functionally characterized here as the ATP-dependent amide-bond-forming catalyst responsible for the biosynthesis of the remaining amide bond present in l-ACL. The results are consistent with the adenylation domain of CapU as the essential catalytic component for l-Lys activation and thioesterification of the adjacent thiolation domain. However, in contrast to expectations, lactamization does not require any additional domains or proteins and is likely a nonenzymatic event. The results set the stage for examining whether a similar NRPS-mediated mechanism is employed in the biosynthesis of other l-ACL-containing natural products and, just as intriguingly, how spontaneous lactamization is avoided in the numerous NRPS-derived peptides that contain an unmodified l-Lys residue.

  15. Chemical Probes Allow Structural Insight into the Condensation Reaction of Nonribosomal Peptide Synthetases.

    Science.gov (United States)

    Bloudoff, Kristjan; Alonzo, Diego A; Schmeing, T Martin

    2016-03-17

    Nonribosomal peptide synthetases (NRPSs) synthesize a vast variety of small molecules, including antibiotics, antitumors, and immunosuppressants. The NRPS condensation (C) domain catalyzes amide bond formation, the central chemical step in nonribosomal peptide synthesis. The catalytic mechanism and substrate determinants of the reaction are under debate. We developed chemical probes to structurally study the NRPS condensation reaction. These substrate analogs become covalently tethered to a cysteine introduced near the active site, to mimic covalent substrate delivery by carrier domains. They are competent substrates in the condensation reaction and behave similarly to native substrates. Co-crystal structures show C domain-substrate interactions, and suggest that the catalytic histidine's principle role is to position the α-amino group for nucleophilic attack. Structural insight provided by these co-complexes also allowed us to alter the substrate specificity profile of the reaction with a single point mutation.

  16. A Proteomic Survey of Nonribosomal Peptide and Polyketide Biosynthesis in Actinobacteria

    OpenAIRE

    Chen, Yunqiu; Ntai, Ioanna; Ju, Kou-San; Unger, Michelle; Zamdborg, Leonid; Robinson, Sarah J.; Doroghazi, James R.; Labeda, David P.; Metcalf, William W.; Kelleher, Neil L.

    2011-01-01

    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 molecule products of these gene clusters still unknown. Here, we employed a “protein-first” method called PrISM (Proteomic Investigation of Secondary Metabolism) to screen 26 unsequenced actinomycetes ...

  17. β-Lactam formation by a non-ribosomal peptide synthetase during antibiotic biosynthesis.

    Science.gov (United States)

    Gaudelli, Nicole M; Long, Darcie H; Townsend, Craig A

    2015-04-16

    Non-ribosomal peptide synthetases are giant enzymes composed of modules that house repeated sets of functional domains, which select, activate and couple amino acids drawn from a pool of nearly 500 potential building blocks. The structurally and stereochemically diverse peptides generated in this manner underlie the biosynthesis of a large sector of natural products. Many of their derived metabolites are bioactive such as the antibiotics vancomycin, bacitracin, daptomycin and the β-lactam-containing penicillins, cephalosporins and nocardicins. Penicillins and cephalosporins are synthesized from a classically derived non-ribosomal peptide synthetase tripeptide (from δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine synthetase). Here we report an unprecedented non-ribosomal peptide synthetase activity that both assembles a serine-containing peptide and mediates its cyclization to the critical β-lactam ring of the nocardicin family of antibiotics. A histidine-rich condensation domain, which typically performs peptide bond formation during product assembly, also synthesizes the embedded four-membered ring. We propose a mechanism, and describe supporting experiments, that is distinct from the pathways that have evolved to the three other β-lactam antibiotic families: penicillin/cephalosporins, clavams and carbapenems. These findings raise the possibility that β-lactam rings can be regio- and stereospecifically integrated into engineered peptides for application as, for example, targeted protease inactivators.

  18. Origins.

    Science.gov (United States)

    Online-Offline, 1999

    1999-01-01

    Provides an annotated list of resources dealing with the theme of origins of life, the universe, and traditions. Includes Web sites, videos, books, audio materials, and magazines with appropriate grade levels and/or subject disciplines indicated; professional resources; and learning activities. (LRW)

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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...

  1. Non-ribosomal peptide synthetases: Identifying the cryptic gene clusters and decoding the natural product

    Indian Academy of Sciences (India)

    MANGAL SINGH; SANDEEP CHAUDHARY; DIPTI SAREEN

    2017-03-01

    Non-ribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs) present in bacteria and fungi are themajor multi-modular enzyme complexes which synthesize secondary metabolites like the pharmacologically importantantibiotics and siderophores. Each of the multiple modules of an NRPS activates a different amino or aryl acid,followed by their condensation to synthesize a linear or cyclic natural product. The studies on NRPS domains, theknowledge of their gene cluster architecture and tailoring enzymes have helped in the in silico genetic screening of theever-expanding sequenced microbial genomic data for the identification of novel NRPS/PKS clusters and thusdeciphering novel non-ribosomal peptides (NRPs). Adenylation domain is an integral part of the NRPSs and is thesubstrate selecting unit for the final assembled NRP. In some cases, it also requires a small protein, the MbtHhomolog, for its optimum activity. The presence of putative adenylation domain and MbtH homologs in a sequencedgenome can help identify the novel secondary metabolite producers. The role of the adenylation domain in the NRPSgene clusters and its characterization as a tool for the discovery of novel cryptic NRPS gene clusters are discussed.

  2. SANDPUMA: Ensemble Predictions of Nonribosomal Peptide Chemistry Reveals Biosynthetic Diversity across Actinobacteria.

    Science.gov (United States)

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

    2017-06-19

    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 7,635 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 , marnix.medema@wur.nl. Supplementary data are available at Bioinformatics online.

  3. Diversity of nature's assembly lines - recent discoveries in non-ribosomal peptide synthesis.

    Science.gov (United States)

    Payne, Jennifer A E; Schoppet, Melanie; Hansen, Mathias Henning; Cryle, Max J

    2016-12-20

    The biosynthesis of complex natural products by non-ribosomal peptide synthetases (NRPSs) and the related polyketide synthases (PKSs) represents a major source of important bioactive compounds. These large, multi-domain machineries are able to produce a fascinating range of molecules due to the nature of their modular architectures, which allows natural products to be assembled and tailored in a modular, step-wise fashion. In recent years there has been significant progress in characterising the important domains and underlying mechanisms of non-ribosomal peptide synthesis. More significantly, several studies have uncovered important examples of novel activity in many NRPS domains. These discoveries not only greatly increase the structural diversity of the possible products of NRPS machineries but - possibly more importantly - they improve our understanding of what is a highly important, yet complex, biosynthetic apparatus. In this review, several recent examples of novel NRPS function will be introduced, which highlight the range of previously uncharacterised activities that have now been detected in the biosynthesis of important natural products by these mega-enzyme synthetases.

  4. Cyclization of polyketides and non-ribosomal peptides on and off their assembly lines.

    Science.gov (United States)

    Pang, Bo; Wang, Min; Liu, Wen

    2016-02-01

    Modular polyketide synthases (PKSs) and non-ribosomal peptide synthetases (NRPSs) are multifunctional megaenzymes that serve as templates to program the assembly of short carboxylic acids and amino acids in a primarily co-linear manner. The variation, combination, permutation and evolution of their functional units (e.g., modules, domains and proteins) along with their association with external enzymes have resulted in the generation of numerous versions of templates, the roles of which have not been fully recognized in the structural diversification of polyketides, non-ribosomal peptides and their hybrids present in nature. In this Highlight, we focus on the assembly-line enzymology and associated chemistry by providing examples of some newly characterized cyclization reactions that occur on and off the assembly lines during and after chain elongation for the purpose of elucidating the template effects of PKSs and NRPSs. A fundamental understanding of the underlying biosynthetic logic would facilitate the elucidation of chemical information contained within the PKS or NRPS templates and benefit the development of strategies for genome mining, biosynthesis-inspired chemical synthesis and combinatorial biosynthesis.

  5. Molecular Cross-Talk between Nonribosomal Peptide Synthetase Carrier Proteins and Unstructured Linker Regions.

    Science.gov (United States)

    Harden, Bradley J; Frueh, Dominique P

    2017-01-24

    Nonribosomal peptide synthetases (NRPSs) employ multiple domains separated by linker regions to incorporate substrates into natural products. During synthesis, substrates are covalently tethered to carrier proteins that translocate between catalytic partner domains. The molecular parameters that govern translocation and associated linker remodeling remain unknown. Here, we used NMR to characterize the structure, dynamics, and invisible states of a peptidyl carrier protein flanked by its linkers. We showed that the N-terminal linker stabilizes and interacts with the protein core while modulating dynamics at specific sites involved in post-translational modifications and/or domain interactions. The results detail the molecular communication between peptidyl carrier proteins and their linkers and could guide efforts in engineering NRPSs to obtain new pharmaceuticals.

  6. Diversity of Nonribosomal Peptide Synthetase Genes in the Microbial Metagenomes of Marine Sponges

    Directory of Open Access Journals (Sweden)

    Ute Hentschel

    2012-05-01

    Full Text Available Genomic mining revealed one major nonribosomal peptide synthetase (NRPS phylogenetic cluster in 12 marine sponge species, one ascidian, an actinobacterial isolate and seawater. Phylogenetic analysis predicts its taxonomic affiliation to the actinomycetes and hydroxy-phenyl-glycine as a likely substrate. Additionally, a phylogenetically distinct NRPS gene cluster was discovered in the microbial metagenome of the sponge Aplysina aerophoba, which shows highest similarities to NRPS genes that were previously assigned, by ways of single cell genomics, to a Chloroflexi sponge symbiont. Genomic mining studies such as the one presented here for NRPS genes, contribute to on-going efforts to characterize the genomic potential of sponge-associated microbiota for secondary metabolite biosynthesis.

  7. 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 product...... of the complex ergot alkaloid (EA) pathway in A. fumigatus. Deletion of either pesL (ΔpesL) or pes1 (Δpes1) resulted in complete loss of fumigaclavine C biosynthesis, relatively increased production of fumitremorgins such as TR-2, fumitremorgin C and verruculogen, increased sensitivity to H2O2, and increased...... sensitivity to the antifungals, voriconazole, and amphotericin B. Deletion of pesL resulted in severely reduced virulence in an invertebrate infection model (P

  8. 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......), 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....

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

    Science.gov (United States)

    Siewers, Verena; Chen, Xiao; Huang, Le; Zhang, Jie; Nielsen, Jens

    2009-11-01

    Non-ribosomal peptides (NRPs) are a diverse family of secondary metabolites with a broad range of biological activities. We started to develop an eukaryotic microbial platform based on the yeast Saccharomyces cerevisiae for heterologous production of NRPs using delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine (ACV) as a model NRP. The Penicillium chrysogenum gene pcbAB encoding ACV synthetase was expressed in S. cerevisiae from a high-copy plasmid together with phosphopantetheinyl transferase (PPTase) encoding genes from Aspergillus nidulans, P. chrysogenum and Bacillus subtilis, and in all the three cases 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 degrees 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.

  10. An update to polyketide synthase and non-ribosomal synthetase genes and nomenclature in Fusarium.

    Science.gov (United States)

    Hansen, Frederik T; Gardiner, Donald M; Lysøe, Erik; Fuertes, Patricia Romans; Tudzynski, Bettina; Wiemann, Philipp; Sondergaard, Teis Esben; Giese, Henriette; Brodersen, Ditlev E; Sørensen, Jens Laurids

    2015-02-01

    Members of the genus Fusarium produce a plethora of bioactive secondary metabolites, which can be harmful to humans and animals or have potential in drug development. In this study we have performed comparative analyses of polyketide synthases (PKSs) and non-ribosomal peptide synthetases (NRPSs) from ten different Fusarium species including F. graminearum (two strains), F. verticillioides, F. solani, F. culmorum, F. pseudograminearum, F. fujikuroi, F. acuminatum, F. avenaceum, F. equiseti, and F. oxysporum (12 strains). This led to identification of 52 NRPS and 52 PKSs orthology groups, respectively, and although not all PKSs and NRPSs are assumed to be intact or functional, the analyses illustrate the huge secondary metabolite potential in Fusarium. In our analyses we identified a core collection of eight NRPSs (NRPS2-4, 6, 10-13) and two PKSs (PKS3 and PKS7) that are conserved in all strains analyzed in this study. The identified PKSs and NRPSs were named based on a previously developed classification system (www.FusariumNRPSPKS.dk). We suggest this system be used when PKSs and NRPSs have to be classified in future sequenced Fusarium strains. This system will facilitate identification of orthologous and non-orthologous NRPSs and PKSs from newly sequenced Fusarium genomes and will aid the scientific community by providing a common nomenclature for these two groups of genes/enzymes.

  11. 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.

  12. Structural and mutational analysis of the nonribosomal peptide synthetase heterocyclization domain provides insight into catalysis.

    Science.gov (United States)

    Bloudoff, Kristjan; Fage, Christopher D; Marahiel, Mohamed A; Schmeing, T Martin

    2017-01-03

    Nonribosomal peptide synthetases (NRPSs) are a family of multidomain, multimodule enzymes that synthesize structurally and functionally diverse peptides, many of which are of great therapeutic or commercial value. The central chemical step of peptide synthesis is amide bond formation, which is typically catalyzed by the condensation (C) domain. In many NRPS modules, the C domain is replaced by the heterocyclization (Cy) domain, a homologous domain that performs two consecutive reactions by using hitherto unknown catalytic mechanisms. It first catalyzes amide bond formation, and then the intramolecular cyclodehydration between a Cys, Ser, or Thr side chain and the backbone carbonyl carbon to form a thiazoline, oxazoline, or methyloxazoline ring. The rings are important for the form and function of the peptide product. We present the crystal structure of an NRPS Cy domain, Cy2 of bacillamide synthetase, at a resolution of 2.3 Å. Despite sharing the same fold, the active sites of C and Cy domains have important differences. The structure allowed us to probe the roles of active-site residues by using mutational analyses in a peptide synthesis assay with intact bacillamide synthetase. The drastically different effects of these mutants, interpreted by using our structural and bioinformatic results, provide insight into the catalytic mechanisms of the Cy domain and implicate a previously unexamined Asp-Thr dyad in catalysis of the cyclodehydration reaction.

  13. Nonribosomal peptide synthase gene clusters for lipopeptide biosynthesis in Bacillus subtilis 916 and their phenotypic functions.

    Science.gov (United States)

    Luo, Chuping; Liu, Xuehui; Zhou, Huafei; Wang, Xiaoyu; Chen, Zhiyi

    2015-01-01

    Bacillus cyclic lipopeptides (LPs) have been well studied for their phytopathogen-antagonistic activities. Recently, research has shown that these LPs also contribute to the phenotypic features of Bacillus strains, such as hemolytic activity, swarming motility, biofilm formation, and colony morphology. Bacillus subtilis 916 not only coproduces the three families of well-known LPs, i.e., surfactins, bacillomycin Ls (iturin family), and fengycins, but also produces a new family of LP called locillomycins. The genome of B. subtilis 916 contains four nonribosomal peptide synthase (NRPS) gene clusters, srf, bmy, fen, and loc, which are responsible for the biosynthesis of surfactins, bacillomycin Ls, fengycins, and locillomycins, respectively. By studying B. subtilis 916 mutants lacking production of one, two, or three LPs, we attempted to unveil the connections between LPs and phenotypic features. We demonstrated that bacillomycin Ls and fengycins contribute mainly to antifungal activity. Although surfactins have weak antifungal activity in vitro, the strain mutated in srfAA had significantly decreased antifungal activity. This may be due to the impaired productions of fengycins and bacillomycin Ls. We also found that the disruption of any LP gene cluster other than fen resulted in a change in colony morphology. While surfactins and bacillomycin Ls play very important roles in hemolytic activity, swarming motility, and biofilm formation, the fengycins and locillomycins had little influence on these phenotypic features. In conclusion, B. subtilis 916 coproduces four families of LPs which contribute to the phenotypic features of B. subtilis 916 in an intricate way.

  14. Stereochemistry and conformation of skyllamycin, a non-ribosomally synthesized peptide from Streptomyces sp. Acta 2897.

    Science.gov (United States)

    Schubert, Vivien; Di Meo, Florent; Saaidi, Pierre-Loïc; Bartoschek, Stefan; Fiedler, Hans-Peter; Trouillas, Patrick; Süssmuth, Roderich D

    2014-04-22

    Skyllamycin is a non-ribosomally synthesized cyclic depsipeptide from Streptomyces sp. Acta 2897 that inhibits PDGF-signaling. The peptide scaffold contains an N-terminal cinnamoyl moiety, a β-methylation of aspartic acid, three β-hydroxylated amino acids and one rarely occurring α-hydroxy glycine. With the exception of α-hydroxy glycine, the stereochemistry of the amino acids was assigned by comparison to synthetic reference amino acids applying chiral GC-MS and Marfey-HPLC analysis. The stereochemistry of α-hydroxy glycine, which is unstable under basic and acidic conditions, was determined by conformational analysis, employing a combination of data from NOESY-NMR spectroscopy, simulated annealing and free MD simulations. The simulation procedures were applied for both R- and S-configured α-hydroxy glycine of the skyllamycin structure and compared to the NOESY data. Both methods, simulated annealing and free MD simulations independently support S-configured α-hydroxy glycine thus enabling the assignment of all stereocenters in the structure of skyllamycin and devising the role of two-component flavin dependent monooxygenase (Sky39) as S-selective.

  15. Photooxidation of the Antimicrobial, Nonribosomal Peptide Bacitracin A by Singlet Oxygen under Environmentally Relevant Conditions.

    Science.gov (United States)

    Lundeen, Rachel A; Chu, Chiheng; Sander, Michael; McNeill, Kristopher

    2016-08-16

    Bacitracin is a mixture of nonribosomal peptides (NRPs) that is extensively used as an antibiotic in both human and veterinary medicine. Despite its widespread use over the past six decades, very few studies have addressed the environmental fate of bacitracin and zinc-bacitracin complexes. In this study, the photochemical transformation of bacitracin components (i.e., cyclic dodecapeptides) in the aquatic environment was investigated. A high resolution mass spectrometry (HRMS)-based approach enabled monitoring of the photochemical degradation kinetics of individual bacitracin components, investigation of the relative contribution of reactive oxygen species (e.g., singlet oxygen, (1)O2) in dissolved organic matter-sensitized photoreactions, and identification of oxidative modifications in bacitracin photoproducts. The results of this study support the hypothesis that indirect photochemical oxidation of the histidine (His) residue by (1)O2 is a major degradation pathway for bacitracin A, the most potent congener of the mixture. Furthermore, the photooxidation rate of bacitracin A with (1)O2 decreased upon bacitracin A coordination with Zn(2+), demonstrating that the photochemistry of metal-bound His is different from that of metal-free His. Overall, these results provide insight into the fate of bacitracin components in the aquatic environment and highlight the potential of utilizing this HRMS-based methodology to study transformations of other environmentally relevant NRPs.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Nonribosomal peptides and polyketides of Burkholderia: new compounds potentially implicated in biocontrol and pharmaceuticals.

    Science.gov (United States)

    Esmaeel, Qassim; Pupin, Maude; Jacques, Philippe; Leclère, Valérie

    2017-05-25

    Bacteria belonging to the genus Burkholderia live in various ecological niches and present a significant role in the environments through the excretion of a wide variety of secondary metabolites including modular nonribosomal peptides (NRPs) and polyketides (PKs). These metabolites represent a widely distributed biomedically and biocontrol important class of natural products including antibiotics, siderophores, and anticancers as well as biopesticides that are considered as a novel source that can be used to defend ecological niche from competitors and to promote plant growth. The aim of this review is to present all NRPs produced or potentially produced by strains of Burkholderia, as NRPs represent a major source of active compounds implicated in biocontrol. The review is a compilation of results from a large screening we have performed on 48 complete sequenced genomes available in NCBI to identify NRPS gene clusters, and data found in the literature mainly because some interesting compounds are produced by strains not yet sequenced. In addition to NRPs, hybrids NRPs/PKs are also included. Specific features about biosynthetic gene clusters and structures of the modular enzymes responsible for the synthesis, the biological activities, and the potential uses in agriculture and pharmaceutical of NRPs and hybrids NRPs/PKs will also be discussed.

  18. Norine, the knowledgebase dedicated to non-ribosomal peptides, is now open to crowdsourcing.

    Science.gov (United States)

    Flissi, Areski; Dufresne, Yoann; Michalik, Juraj; Tonon, Laurie; Janot, Stéphane; Noé, Laurent; Jacques, Philippe; Leclère, Valérie; Pupin, Maude

    2016-01-01

    Since its creation in 2006, Norine remains the unique knowledgebase dedicated to non-ribosomal peptides (NRPs). These secondary metabolites, produced by bacteria and fungi, harbor diverse interesting biological activities (such as antibiotic, antitumor, siderophore or surfactant) directly related to the diversity of their structures. The Norine team goal is to collect the NRPs and provide tools to analyze them efficiently. We have developed a user-friendly interface and dedicated tools to provide a complete bioinformatics platform. The knowledgebase gathers abundant and valuable annotations on more than 1100 NRPs. To increase the quantity of described NRPs and improve the quality of associated annotations, we are now opening Norine to crowdsourcing. We believe that contributors from the scientific community are the best experts to annotate the NRPs they work on. We have developed MyNorine to facilitate the submission of new NRPs or modifications of stored ones. This article presents MyNorine and other novelties of Norine interface released since the first publication. Norine is freely accessible from the following URL: http://bioinfo.lifl.fr/NRP.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Kinetics profiling of gramicidin S synthetase A, a member of nonribosomal peptide synthetases.

    Science.gov (United States)

    Sun, Xun; Li, Hao; Alfermann, Jonas; Mootz, Henning D; Yang, Haw

    2014-12-23

    Nonribosomal peptide synthetases (NRPS) incorporate assorted amino acid substrates into complex natural products. The substrate is activated via the formation of a reactive aminoacyl adenylate and is subsequently attached to the protein template via a thioester bond. The reactive nature of such intermediates, however, leads to side reactions that also break down the high-energy anhydride bond. The off-pathway kinetics or their relative weights compared to that of the on-pathway counterpart remains generally elusive. Here, we introduce multiplatform kinetics profiling to quantify the relative weights of on- and off-pathway reactions. Using the well-defined stoichiometry of thioester formation, we integrate a mass spectrometry (MS) kinetics assay, a high-performance liquid chromatography (HPLC) assay, and an ATP-pyrophosphate (PPi) exchange assay to map out a highly efficient on-pathway kinetics profile of the substrate activation and intermediate uploading (>98% relative weight) for wide-type gramicidin S synthetase A (GrsA) and a 87% rate profile for a cysteine-free GrsA mutant. Our kinetics profiling approach complements the existing enzyme-coupled byproduct-release assays, unraveling new mechanistic insights of substrate activation/channeling in NRPS enzymes.

  1. Nonribosomal peptides, key biocontrol components for Pseudomonas fluorescens In5, isolated from a Greenlandic suppressive soil.

    Science.gov (United States)

    Michelsen, Charlotte F; Watrous, Jeramie; Glaring, Mikkel A; Kersten, Roland; Koyama, Nobuhiro; Dorrestein, Pieter C; Stougaard, Peter

    2015-03-17

    Potatoes are cultivated in southwest Greenland without the use of pesticides and with limited crop rotation. Despite the fact that plant-pathogenic fungi are present, no severe-disease outbreaks have yet been observed. In this report, we document that a potato soil at Inneruulalik in southern Greenland is suppressive against Rhizoctonia solani Ag3 and uncover the suppressive antifungal mechanism of a highly potent biocontrol bacterium, Pseudomonas fluorescens In5, isolated from the suppressive potato soil. A combination of molecular genetics, genomics, and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) imaging mass spectrometry (IMS) revealed an antifungal genomic island in P. fluorescens In5 encoding two nonribosomal peptides, nunamycin and nunapeptin, which are key components for the biocontrol activity by strain In5 in vitro and in soil microcosm experiments. Furthermore, complex microbial behaviors were highlighted. Whereas nunamycin was demonstrated to inhibit the mycelial growth of R. solani Ag3, but not that of Pythium aphanidermatum, nunapeptin instead inhibited P. aphanidermatum but not R. solani Ag3. Moreover, the synthesis of nunamycin by P. fluorescens In5 was inhibited in the presence of P. aphanidermatum. Further characterization of the two peptides revealed nunamycin to be a monochlorinated 9-amino-acid cyclic lipopeptide with similarity to members of the syringomycin group, whereas nunapeptin was a 22-amino-acid cyclic lipopeptide with similarity to corpeptin and syringopeptin. Crop rotation and systematic pest management are used to only a limited extent in Greenlandic potato farming. Nonetheless, although plant-pathogenic fungi are present in the soil, the farmers do not experience major plant disease outbreaks. Here, we show that a Greenlandic potato soil is suppressive against Rhizoctonia solani, and we unravel the key biocontrol components for Pseudomonas fluorescens In5, one of the potent biocontrol bacteria

  2. Characterization of native 40 S particles from Krebs II mouse ascites tumor cells: resolution, nomenclature and molecular weights of the nonribosomal proteins

    DEFF Research Database (Denmark)

    Reichert, G; Issinger, O G

    1981-01-01

    Native 40 S particles from Krebs II mouse ascites tumor cells were isolated on a large scale. A nonribosomal protein moiety of about 30 proteins could be removed from the ribosomal particles by treatment with 250 mM KCl. These proteins were analysed by two-dimensional polyacrylamide gel electroph......Native 40 S particles from Krebs II mouse ascites tumor cells were isolated on a large scale. A nonribosomal protein moiety of about 30 proteins could be removed from the ribosomal particles by treatment with 250 mM KCl. These proteins were analysed by two-dimensional polyacrylamide gel...

  3. Phosphorylation in vivo of non-ribosomal proteins from native 40 S ribosomal particles of Krebs II mouse ascites-tumour cells

    DEFF Research Database (Denmark)

    Schuck, J; Reichert, G; Issinger, O G

    1981-01-01

    Four non-ribosomal proteins from native 40 S ribosomal subunits with mol.wts. of 110 000, 84 000, 68 000 and 26 000 were phosphorylated in vivo when ascites cells were incubated in the presence of [32P]Pi. The 110 000-, 84 000- and 26 000-dalton proteins are identical with phosphorylated products...

  4. Characterization of native 40 S particles from Krebs II mouse ascites tumor cells: resolution, nomenclature and molecular weights of the nonribosomal proteins

    DEFF Research Database (Denmark)

    Reichert, G; Issinger, O G

    1981-01-01

    Native 40 S particles from Krebs II mouse ascites tumor cells were isolated on a large scale. A nonribosomal protein moiety of about 30 proteins could be removed from the ribosomal particles by treatment with 250 mM KCl. These proteins were analysed by two-dimensional polyacrylamide gel electroph...

  5. Predicted class-I aminoacyl tRNA synthetase-like proteins in non-ribosomal peptide synthesis

    Directory of Open Access Journals (Sweden)

    Iyer Lakshminarayan M

    2010-08-01

    Full Text Available Abstract Background Recent studies point to a great diversity of non-ribosomal peptide synthesis systems with major roles in amino acid and co-factor biosynthesis, secondary metabolism, and post-translational modifications of proteins by peptide tags. The least studied of these systems are those utilizing tRNAs or aminoacyl-tRNA synthetases (AAtRS in non-ribosomal peptide ligation. Results Here we describe novel examples of AAtRS related proteins that are likely to be involved in the synthesis of widely distributed peptide-derived metabolites. Using sensitive sequence profile methods we show that the cyclodipeptide synthases (CDPSs are members of the HUP class of Rossmannoid domains and are likely to be highly derived versions of the class-I AAtRS catalytic domains. We also identify the first eukaryotic CDPSs in fungi and in animals; they might be involved in immune response in the latter organisms. We also identify a paralogous version of the methionyl-tRNA synthetase, which is widespread in bacteria, and present evidence using contextual information that it might function independently of protein synthesis as a peptide ligase in the formation of a peptide- derived secondary metabolite. This metabolite is likely to be heavily modified through multiple reactions catalyzed by a metal-binding cupin domain and a lysine N6 monooxygenase that are strictly associated with this paralogous methionyl-tRNA synthetase (MtRS. We further identify an analogous system wherein the MtRS has been replaced by more typical peptide ligases with the ATP-grasp or modular condensation-domains. Conclusions The prevalence of these predicted biosynthetic pathways in phylogenetically distant, pathogenic or symbiotic bacteria suggests that metabolites synthesized by them might participate in interactions with the host. More generally, these findings point to a complete spectrum of recruitment of AAtRS to various non-ribosomal biosynthetic pathways, ranging from the

  6. The Stress-responsive and Host-oriented Role of Nonribosomal Peptide Synthetases in an Entomopathogenic Fungus, Beauveria bassiana.

    Science.gov (United States)

    Liu, Hang; Xie, Linan; Wang, Jing; Guo, Qiannan; Yang, Shengnan; Liang, Pei; Wang, Chengshu; Lin, Min; Xu, Yuquan; Zhang, Liwen

    2016-11-14

    Beauveria bassiana infects numbers of pest species and is known to produce insecticidal substances, e.g., the nonribosomal peptides (NRPs) beauvericin and bassianolide. However, most NRPs and their biological roles in B. bassiana remain undiscovered. To identify NRPs that potentially contribute to pathogenesis, the 21 predicted NRP synthetases (NRPSs) or NRPS-like proteins of B. bassiana ARSEF2860 were primarily ranked into three functional groups: basic metabolism (7 NRPSs), pathogenicity (12 NRPSs) and unknown function (2 NRPSs). Based on the transcript levels during in vivo growth on diamondback moth (Plutella xylostella, Linnaeus), half of the Group II NRPSs were likely to be involved in infection. Given that the metabolites biosynthesized by these NRPSs remaining to determined, our result underlines the importance of NRPSome in fungal pathogenesis, and will serve as a guide for future genomic mining projects to discover functionally essential and structurally diverse NRPs in fungal genomes.

  7. 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.

  8. Nonribosomal peptide synthetase genes pesL and pes1 are essential for Fumigaclavine C production in Aspergillus fumigatus.

    Science.gov (United States)

    O'Hanlon, Karen A; Gallagher, Lorna; Schrettl, Markus; Jöchl, Christoph; Kavanagh, Kevin; Larsen, Thomas O; Doyle, Sean

    2012-05-01

    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 product of the complex ergot alkaloid (EA) pathway in A. fumigatus. Deletion of either pesL (ΔpesL) or pes1 (Δpes1) resulted in complete loss of fumigaclavine C biosynthesis, relatively increased production of fumitremorgins such as TR-2, fumitremorgin C and verruculogen, increased sensitivity to H(2)O(2), and increased sensitivity to the antifungals, voriconazole, and amphotericin B. Deletion of pesL resulted in severely reduced virulence in an invertebrate infection model (P < 0.001). These findings indicate that NRP synthesis plays an essential role in mediating the final prenylation step of the EA pathway, despite the apparent absence of NRP synthetases in the proposed EA biosynthetic cluster for A. fumigatus. Liquid chromatography/diode array detection/mass spectrometry analysis also revealed the presence of fumiquinazolines A to F in both A. fumigatus wild-type and ΔpesL strains. This observation suggests that alternative NRP synthetases can also function in fumiquinazoline biosynthesis, since PesL has been shown to mediate fumiquinazoline biosynthesis in vitro. Furthermore, we provide here the first direct link between EA biosynthesis and virulence, in agreement with the observed toxicity associated with EA exposure. Finally, we demonstrate a possible cluster cross-talk phenomenon, a theme which is beginning to emerge in the literature.

  9. 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

    2016-04-16

    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.

  10. 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

  11. Insect-specific polyketide synthases (PKSs), potential PKS-nonribosomal peptide synthetase hybrids, and novel PKS clades in tropical fungi.

    Science.gov (United States)

    Amnuaykanjanasin, Alongkorn; Phonghanpot, Suranat; Sengpanich, Nattapong; Cheevadhanarak, Supapon; Tanticharoen, Morakot

    2009-06-01

    Polyketides draw much attention because of their potential use in pharmaceutical and biotechnological applications. This study identifies an abundant pool of polyketide synthase (PKS) genes from local isolates of tropical fungi found in Thailand in three different ecological niches: insect pathogens, marine inhabitants, and lichen mutualists. We detected 149 PKS genes from 48 fungi using PCR with PKS-specific degenerate primers. We identified and classified 283 additional PKS genes from 13 fungal genomes. Phylogenetic analysis of all these PKS sequences the comprising ketosynthase (KS) conserved region and the KS-acyltransferase interdomain region yielded results very similar to those for phylogenies of the KS domain and suggested a number of remarkable points. (i) Twelve PKS genes amplified from 12 different insect-pathogenic fungi form a tight cluster, although along with two PKS genes extracted from genomes of Aspergillus niger and Aspergillus terreus, in reducing clade III. Some of these insect-specific fungal PKSs are nearly identical. (ii) We identified 38 new PKS-nonribosomal peptide synthetase hybrid genes in reducing clade II. (iii) Four distinct clades were discovered with more than 75% bootstrap support. We propose to designate the novel clade D1 with 100% bootstrap support "reducing clade V." The newly cloned PKS genes from these tropical fungi should provide useful and diverse genetic resources for future research on the characterization of polyketide compounds synthesized by these enzymes.

  12. New Insight into the Ochratoxin A Biosynthetic Pathway through Deletion of a Nonribosomal Peptide Synthetase Gene in Aspergillus carbonarius

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, A.; Bruno, K. S.; Solfrizzo, M.; Perrone, G.; Mule, G.; Visconti, A.; Baker, S. E.

    2012-09-14

    Ochratoxin A (OTA), a mycotoxin produced by Aspergillus and Penicillium species, is composed of a dihydroisocoumarin ring linked to phenylalanine and its biosynthetic pathway has not yet been completely elucidated. Most of the knowledge regarding the genetic and enzymatic aspects of OTA biosynthesis has been obtained in Penicillium species. In Aspergillus species only pks genes involved in the initial steps of the pathway have been partially characterized. In our study, the inactivation of a gene encoding a nonribosomal peptide synthetase in OTA producing A. carbonarius ITEM 5010 has removed the ability of the fungus to produce OTA. This is the first report on the involvement of an nrps gene product in OTA biosynthetic pathway in Aspergillus species. The absence of OTA and ochratoxin α-the isocoumaric derivative of OTA, and the concomitant increase of ochratoxin β- the dechloro analog of ochratoxin α- were observed in the liquid culture of transformed strain. The data provide the first evidence that the enzymatic step adding phenylalanine to polyketide dihydroisocoumarin precedes the chlorination step to form OTA in A. carbonarius, and that ochratoxin α is a product of hydrolysis of OTA, giving an interesting new insight in the biosynthetic pathway of the toxin.

  13. 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.

    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.

  14. Hassallidins, antifungal glycolipopeptides, are widespread among cyanobacteria and are the end-product of a nonribosomal pathway.

    Science.gov (United States)

    Vestola, Johanna; Shishido, Tania K; Jokela, Jouni; Fewer, David P; Aitio, Olli; Permi, Perttu; Wahlsten, Matti; Wang, Hao; Rouhiainen, Leo; Sivonen, Kaarina

    2014-05-06

    Cyanobacteria produce a wide variety of cyclic peptides, including the widespread hepatotoxins microcystins and nodularins. Another class of peptides, cyclic glycosylated lipopeptides called hassallidins, show antifungal activity. Previously, two hassallidins (A and B) were reported from an epilithic cyanobacterium Hassallia sp. and found to be active against opportunistic human pathogenic fungi. Bioinformatic analysis of the Anabaena sp. 90 genome identified a 59-kb cryptic inactive nonribosomal peptide synthetase gene cluster proposed to be responsible for hassallidin biosynthesis. Here we describe the hassallidin biosynthetic pathway from Anabaena sp. SYKE748A, as well as the large chemical variation and common occurrence of hassallidins in filamentous cyanobacteria. Analysis demonstrated that 20 strains of the genus Anabaena carry hassallidin synthetase genes and produce a multitude of hassallidin variants that exhibit activity against Candida albicans. The compounds discovered here were distinct from previously reported hassallidins A and B. The IC50 of hassallidin D was 0.29-1.0 µM against Candida strains. A large variation in amino acids, sugars, their degree of acetylation, and fatty acid side chain length was detected. In addition, hassallidins were detected in other cyanobacteria including Aphanizomenon, Cylindrospermopsis raciborskii, Nostoc, and Tolypothrix. These compounds may protect some of the most important bloom-forming and globally distributed cyanobacteria against attacks by parasitic fungi.

  15. The long-overlooked enzymology of a nonribosomal peptide synthetase-independent pathway for virulence-conferring siderophore biosynthesis.

    Science.gov (United States)

    Oves-Costales, Daniel; Kadi, Nadia; Challis, Gregory L

    2009-11-21

    Siderophores are high-affinity ferric iron chelators biosynthesised and excreted by most microorganisms that play an important role in iron acquisition. Siderophore-mediated scavenging of ferric iron from hosts contributes significantly to the virulence of pathogenic microbes. As a consequence siderophore biosynthesis is an attractive target for chemotherapeutic intervention. Two main pathways for siderophore biosynthesis exist in microbes. One pathway involves nonribosomal peptide synthetase (NRPS) multienzymes while the other is NRPS-independent. The enzymology of NRPS-mediated siderophore biosynthesis has been extensively studied for more than a decade. In contrast, the enzymology of NRPS-independent siderophore (NIS) biosynthesis was overlooked for almost thirty years since the first genetic characterisation of the NIS biosynthetic pathway to aerobactin. However, the past three years have witnessed an explosion of interest in the enzymology of NIS synthetases, the key enzymes in the assembly of siderophores via the NIS pathway. The biochemical characterisation of ten purified recombinant synthetases has been reported since 2007, along with the first structural characterisation of a synthetase by X-ray crystallography in 2009. In this feature article we summarise the recent progress that has been made in understanding the long-overlooked enzymology of NRPS-independent siderophore biosynthesis, highlight important remaining questions, and suggest likely directions for future research.

  16. Vibriobactin biosynthesis in Vibrio cholerae: VibH is an amide synthase homologous to nonribosomal peptide synthetase condensation domains.

    Science.gov (United States)

    Keating, T A; Marshall, C G; Walsh, C T

    2000-12-19

    The Vibrio cholerae siderophore vibriobactin is biosynthesized from three molecules of 2,3-dihydroxybenzoate (DHB), two molecules of L-threonine, and one of norspermidine. Of the four genes positively implicated in vibriobactin biosynthesis, we have here expressed, purified, and assayed the products of three: vibE, vibB, and vibH. All three are homologous to nonribosomal peptide synthetase (NRPS) domains: VibE is a 2,3-dihydroxybenzoate-adenosyl monophosphate ligase, VibB is a bifunctional isochorismate lyase-aryl carrier protein (ArCP), and VibH is a novel amide synthase that represents a free-standing condensation (C) domain. VibE and VibB are homologous to EntE and EntB from Escherichia coli enterobactin synthetase; VibE activates DHB as the acyl adenylate and then transfers it to the free thiol of the phosphopantetheine arm of VibB's ArCP domain. VibH then condenses this DHB thioester (the donor) with the small molecule norspermidine (the acceptor), forming N(1)-(2, 3-dihydroxybenzoyl)norspermidine (DHB-NSPD) with a k(cat) of 600 min(-1) and a K(m) for acyl-VibB of 0.88 microM and for norspermidine of 1.5 mM. Exclusive monoacylation of a primary amine of norspermidine was observed. VibH also tolerates DHB-acylated EntB and 1,7-diaminoheptane, octylamine, and hexylamine as substrates, albeit at lowered catalytic efficiencies. DHB-NSPD possesses one of three acylations required for mature vibriobactin, and its formation confirms VibH's role in vibriobactin biosynthesis. VibH is a unique NRPS condensation domain that acts upon an upstream carrier-protein-bound donor and a downstream amine, turning over a soluble amide product, in contrast to an archetypal NRPS-embedded C domain that condenses two carrier protein thioesters.

  17. The crystal structure of BlmI as a model for nonribosomal peptide synthetase peptidyl carrier proteins.

    Science.gov (United States)

    Lohman, Jeremy R; Ma, Ming; Cuff, Marianne E; Bigelow, Lance; Bearden, Jessica; Babnigg, Gyorgy; Joachimiak, Andrzej; Phillips, George N; Shen, Ben

    2014-07-01

    Carrier proteins (CPs) play a critical role in the biosynthesis of various natural products, especially in nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) enzymology, where the CPs are referred to as peptidyl-carrier proteins (PCPs) or acyl-carrier proteins (ACPs), respectively. CPs can either be a domain in large multifunctional polypeptides or standalone proteins, termed Type I and Type II, respectively. There have been many biochemical studies of the Type I PKS and NRPS CPs, and of Type II ACPs. However, recently a number of Type II PCPs have been found and biochemically characterized. In order to understand the possible interaction surfaces for combinatorial biosynthetic efforts we crystallized the first characterized and representative Type II PCP member, BlmI, from the bleomycin biosynthetic pathway from Streptomyces verticillus ATCC 15003. The structure is similar to CPs in general but most closely resembles PCPs. Comparisons with previously determined PCP structures in complex with catalytic domains reveals a common interaction surface. This surface is highly variable in charge and shape, which likely confers specificity for interactions. Previous nuclear magnetic resonance (NMR) analysis of a prototypical Type I PCP excised from the multimodular context revealed three conformational states. Comparison of the states with the structure of BlmI and other PCPs reveals that only one of the NMR states is found in other studies, suggesting the other two states may not be relevant. The state represented by the BlmI crystal structure can therefore serve as a model for both Type I and Type II PCPs.

  18. Type I pyridoxal 5'-phosphate dependent enzymatic domains embedded within multimodular nonribosomal peptide synthetase and polyketide synthase assembly lines.

    Science.gov (United States)

    Milano, Teresa; Paiardini, Alessandro; Grgurina, Ingeborg; Pascarella, Stefano

    2013-10-23

    Pyridoxal 5'-phosphate (PLP)-dependent enzymes of fold type I, the most studied structural class of the PLP-dependent enzyme superfamily, are known to exist as stand-alone homodimers or homotetramers. These enzymes have been found also embedded in multimodular and multidomain assembly lines involved in the biosynthesis of polyketides (PKS) and nonribosomal peptides (NRPS). The aim of this work is to provide a proteome-wide view of the distribution and characteristics of type I domains covalently integrated in these assemblies in prokaryotes. An ad-hoc Hidden Markov profile was calculated using a sequence alignment derived from a multiple structural superposition of distantly related PLP-enzymes of fold type I. The profile was utilized to scan the sequence databank and to collect the proteins containing at least one type I domain linked to a component of an assembly line in bacterial genomes. The domains adjacent to a carrier protein were further investigated. Phylogenetic analysis suggested the presence of four PLP-dependent families: Aminotran_3, Beta_elim_lyase and Pyridoxal_deC, occurring mainly within mixed NRPS/PKS clusters, and Aminotran_1_2 found mainly in PKS clusters. Sequence similarity to the reference PLP enzymes with solved structures ranged from 24 to 42% identity. Homology models were built for each representative type I domain and molecular docking simulations with putative substrates were carried out. Prediction of the protein-protein interaction sites evidenced that the surface regions of the type I domains embedded within multienzyme assemblies were different from those of the self-standing enzymes; these structural features appear to be required for productive interactions with the adjacent domains in a multidomain context. This work provides a systematic view of the occurrence of type I domain within NRPS and PKS assembly lines and it predicts their structural characteristics using computational methods. Comparison with the corresponding stand

  19. Molecular genetic analysis reveals that a nonribosomal peptide synthetase-like (NRPS-like) gene in Aspergillus nidulans is responsible for microperfuranone biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Hsu-Hua; Chiang, Yi Ming; Entwistle, Ruth; Ahuja, Mammeet; Lee, Kuan-Han; Bruno, Kenneth S.; Wu, Tung-Kung; Oakley, Berl R.; Wang, Clay C.

    2012-04-10

    Genome sequencing of Aspergillus species including A. nidulans has revealed that there are far more secondary metabolite biosynthetic gene clusters than secondary metabolites isolated from these organisms. This implies that these organisms can produce additional secondary metabolites have not yet been elucidated. The A. nidulans genome contains twelve nonribosomal peptide synthetase (NRPS), one hybrid polyketide synthase/nonribosomal peptide synthetase (PKS/NRPS), and fourteen NRPS-like genes. The only NRPS-like gene in A. nidulans with a known product is tdiA which is involved in terrequinone A biosynthesis. To attempt to identify the products of these NRPS-like genes, we replaced the native promoters of the NRPS-like genes with the inducible alcohol dehydrogenase (alcA) promoter. Our results demonstrated that induction of the single NRPS-like gene AN3396.4 led to the enhanced production of microperfuranone. Furthermore, heterologous expression of AN3396.4 in A. niger confirmed that only one NRPS-like gene, AN3396.4, is necessary for the production of microperfuranone.

  20. Discovery of antibacterials and other bioactive compounds from microorganisms-evaluating methodologies for discovery and generation of non-ribosomal peptide antibiotics.

    Science.gov (United States)

    Witting, K; Süssmuth, R D

    2011-10-01

    After decades of neglect in industrial research the comeback of natural products is due since improved screening approaches are at disposal, yielding a multitude of new compounds from natural sources. Besides traditional compound libraries peptides are characterized by an enormous structural complexity, thus increasing the chance of finding a hit in a screening. Emphasizing antibacterial compounds structural complexity is a prerequisite for their success. This review focuses on the screening approaches employed for the discovery of mostly antibacterial, non-ribosomal peptides derived from natural sources. Traditional screening methodologies as well as genetic approaches are discussed in this context. Utilizing genetic engineering methods e.g., precursor-directed biosynthesis, mutasynthesis, combinatorial biosynthesis, as well as chemoenzymatics to achieve greater structural diversity is thoroughly discussed and exemplified by recent discoveries.

  1. Surveys of non-ribosomal peptide and polyketide assembly lines in fungi and prospects for their analysis in vitro and in vivo.

    Science.gov (United States)

    Evans, Bradley S; Robinson, Sarah J; Kelleher, Neil L

    2011-01-01

    With many bioactive non-ribosomal peptides and polyketides produced in fungi, studies of their biosyntheses are an active area of research. Practical limitations of working with mega-dalton synthetases including cell lysis and protein extraction to recombinant gene and pathway expression has slowed understanding of many secondary metabolic processes relative to bacterial counterparts. Recent advances in accessing fungal biosynthetic machinery are beginning to change this. Here we describe the successes of some studies of thiotemplate biosynthesis in fungal systems, along with very recent advances in chemical tagging and mass spectrometric strategies to selectively study biosynthetic conveyer belts in isolation, and within a few years, in endogenous fungal proteomes. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Accurate Detection of Adenylation Domain Functions in Nonribosomal Peptide Synthetases by an Enzyme-linked Immunosorbent Assay System Using Active Site-directed Probes for Adenylation Domains.

    Science.gov (United States)

    Ishikawa, Fumihiro; Miyamoto, Kengo; Konno, Sho; Kasai, Shota; Kakeya, Hideaki

    2015-12-18

    A significant gap exists between protein engineering and enzymes used for the biosynthesis of natural products, largely because there is a paucity of strategies that rapidly detect active-site phenotypes of the enzymes with desired activities. Herein, we describe a proof-of-concept study of an enzyme-linked immunosorbent assay (ELISA) system for the adenylation (A) domains in nonribosomal peptide synthetases (NRPSs) using a combination of active site-directed probes coupled to a 5'-O-N-(aminoacyl)sulfamoyladenosine scaffold with a biotin functionality that immobilizes probe molecules onto a streptavidin-coated solid support. The recombinant NRPSs have a C-terminal His-tag motif that is targeted by an anti-6×His mouse antibody as the primary antibody and a horseradish peroxidase-linked goat antimouse antibody as the secondary antibody. These probes can selectively capture the cognate A domains by ligand-directed targeting. In addition, the ELISA technique detected A domains in the crude cell-free homogenates from the Escherichia coli expression systems. When coupled with a chromogenic substrate, the antibody-based ELISA technique can visualize probe-protein binding interactions, which provides accurate readouts of the A-domain functions in NRPS enzymes. To assess the ELISA-based engineering of the A domains of NRPSs, we reprogramed 2,3-dihydroxybenzoic acid (DHB)-activating enzyme EntE toward salicylic acid (Sal)-activating enzymes and investigated a correlation between binding properties for probe molecules and enzyme catalysts. We generated a mutant of EntE that displayed negligible loss in the kcat/Km value with the noncognate substrate Sal and a corresponding 48-fold decrease in the kcat/Km value with the cognate substrate DHB. The resulting 26-fold switch in substrate specificity was achieved by the replacement of a Ser residue in the active site of EntE with a Cys toward the nonribosomal codes of Sal-activating enzymes. Bringing a laboratory ELISA technique

  3. The majority of total nuclear-encoded non-ribosomal RNA in a human cell is 'dark matter' un-annotated RNA

    Directory of Open Access Journals (Sweden)

    Milos Patrice

    2010-12-01

    Full Text Available Abstract Background Discovery that the transcriptional output of the human genome is far more complex than predicted by the current set of protein-coding annotations and that most RNAs produced do not appear to encode proteins has transformed our understanding of genome complexity and suggests new paradigms of genome regulation. However, the fraction of all cellular RNA whose function we do not understand and the fraction of the genome that is utilized to produce that RNA remain controversial. This is not simply a bookkeeping issue because the degree to which this un-annotated transcription is present has important implications with respect to its biologic function and to the general architecture of genome regulation. For example, efforts to elucidate how non-coding RNAs (ncRNAs regulate genome function will be compromised if that class of RNAs is dismissed as simply 'transcriptional noise'. Results We show that the relative mass of RNA whose function and/or structure we do not understand (the so called 'dark matter' RNAs, as a proportion of all non-ribosomal, non-mitochondrial human RNA (mt-RNA, can be greater than that of protein-encoding transcripts. This observation is obscured in studies that focus only on polyA-selected RNA, a method that enriches for protein coding RNAs and at the same time discards the vast majority of RNA prior to analysis. We further show the presence of a large number of very long, abundantly-transcribed regions (100's of kb in intergenic space and further show that expression of these regions is associated with neoplastic transformation. These overlap some regions found previously in normal human embryonic tissues and raises an interesting hypothesis as to the function of these ncRNAs in both early development and neoplastic transformation. Conclusions We conclude that 'dark matter' RNA can constitute the majority of non-ribosomal, non-mitochondrial-RNA and a significant fraction arises from numerous very long

  4. Ces locus embedded proteins control the non-ribosomal synthesis of the cereulide toxin in emetic Bacillus cereus on multiple levels

    Science.gov (United States)

    Lücking, Genia; Frenzel, Elrike; Rütschle, Andrea; Marxen, Sandra; Stark, Timo D.; Hofmann, Thomas; Scherer, Siegfried; Ehling-Schulz, Monika

    2015-01-01

    The emetic toxin cereulide produced by Bacillus cereus is synthesized by the modular enzyme complex Ces that is encoded on a pXO1-like megaplasmid. To decipher the role of the genes adjacent to the structural genes cesA/cesB, coding for the non-ribosomal peptide synthetase (NRPS), gene inactivation- and overexpression mutants of the emetic strain F4810/72 were constructed and their impact on cereulide biosynthesis was assessed. The hydrolase CesH turned out to be a part of the complex regulatory network controlling cereulide synthesis on a transcriptional level, while the ABC transporter CesCD was found to be essential for post-translational control of cereulide synthesis. Using a gene inactivation approach, we show that the NRPS activating function of the phosphopantetheinyl transferase (PPtase) embedded in the ces locus was complemented by a chromosomally encoded Sfp-like PPtase, representing an interesting example for the functional interaction between a plasmid encoded NRPS and a chromosomally encoded activation enzyme. In summary, our results highlight the complexity of cereulide biosynthesis and reveal multiple levels of toxin formation control. ces operon internal genes were shown to play a pivotal role by acting at different levels of toxin production, thus complementing the action of the chromosomal key transcriptional regulators AbrB and CodY. PMID:26528255

  5. Ces locus embedded proteins control the non-ribosomal synthesis of the cereulide toxin in emetic Bacillus cereus on multiple levels.

    Science.gov (United States)

    Lücking, Genia; Frenzel, Elrike; Rütschle, Andrea; Marxen, Sandra; Stark, Timo D; Hofmann, Thomas; Scherer, Siegfried; Ehling-Schulz, Monika

    2015-01-01

    The emetic toxin cereulide produced by Bacillus cereus is synthesized by the modular enzyme complex Ces that is encoded on a pXO1-like megaplasmid. To decipher the role of the genes adjacent to the structural genes cesA/cesB, coding for the non-ribosomal peptide synthetase (NRPS), gene inactivation- and overexpression mutants of the emetic strain F4810/72 were constructed and their impact on cereulide biosynthesis was assessed. The hydrolase CesH turned out to be a part of the complex regulatory network controlling cereulide synthesis on a transcriptional level, while the ABC transporter CesCD was found to be essential for post-translational control of cereulide synthesis. Using a gene inactivation approach, we show that the NRPS activating function of the phosphopantetheinyl transferase (PPtase) embedded in the ces locus was complemented by a chromosomally encoded Sfp-like PPtase, representing an interesting example for the functional interaction between a plasmid encoded NRPS and a chromosomally encoded activation enzyme. In summary, our results highlight the complexity of cereulide biosynthesis and reveal multiple levels of toxin formation control. ces operon internal genes were shown to play a pivotal role by acting at different levels of toxin production, thus complementing the action of the chromosomal key transcriptional regulators AbrB and CodY.

  6. A sensitive single-enzyme assay system using the non-ribosomal peptide synthetase BpsA for measurement of L-glutamine in biological samples

    Science.gov (United States)

    Brown, Alistair S.; Robins, Katherine J.; Ackerley, David F.

    2017-01-01

    The ability to rapidly, economically and accurately measure L-glutamine concentrations in biological samples is important for many areas of research, medicine or industry, however there is room for improvement on existing methods. We describe here how the enzyme BpsA, a single-module non-ribosomal peptide synthetase able to convert L-glutamine into the blue pigment indigoidine, can be used to accurately measure L-glutamine in biological samples. Although indigoidine has low solubility in aqueous solutions, meaning direct measurements of indigoidine synthesis do not reliably yield linear standard curves, we demonstrate that resolubilisation of the reaction end-products in DMSO overcomes this issue and that spontaneous reduction to colourless leuco-indigoidine occurs too slowly to interfere with assay accuracy. Our protocol is amenable to a 96-well microtitre format and can be used to measure L-glutamine in common bacterial and mammalian culture media, urine, and deproteinated plasma. We show that active BpsA can be prepared in high yield by expressing it in the apo-form to avoid the toxicity of indigoidine to Escherichia coli host cells, then activating it to the holo-form in cell lysates prior to purification; and that BpsA has a lengthy shelf-life, retaining >95% activity when stored at either −20 °C or 4 °C for 24 weeks. PMID:28139746

  7. Identification of the non-ribosomal peptide synthetase responsible for biosynthesis of the potential anti-cancer drug sansalvamide in Fusarium solani.

    Science.gov (United States)

    Romans-Fuertes, Patricia; Sondergaard, Teis Esben; Sandmann, Manuela Ilse Helga; Wollenberg, Rasmus Dam; Nielsen, Kristian Fog; Hansen, Frederik T; Giese, Henriette; Brodersen, Ditlev Egeskov; Sørensen, Jens Laurids

    2016-11-01

    Sansalvamide is a cyclic pentadepsipeptide produced by Fusarium solani and has shown promising results as potential anti-cancer drug. The biosynthetic pathway has until now remained unidentified, but here we used an Agrobacterium tumefaciens-mediated transformation (ATMT) approach to generate knockout mutants of two candidate non-ribosomal peptide synthetases (NRPS29 and NRPS30). Comparative studies of secondary metabolites in the two deletion mutants and wild type confirmed the absence of sansalvamide in the NRPS30 deletion mutant, implicating this synthetase in the biosynthetic pathway for sansalvamide. Sansalvamide is structurally related to the cyclic hexadepsipeptide destruxin, which both contain an α-hydroxyisocaproic acid (HICA) unit. A gene cluster responsible for destruxin production has previously been identified in Metarhizium robertsii together with a hypothetical biosynthetic pathway. Using comparative bioinformatic analyses of the catalytic domains in the destruxin and sansalvamide NRPSs, we were able to propose a model for sansalvamide biosynthesis. Orthologues of the gene clusters were also identified in species from several other genera including Acremonium chrysogenum and Trichoderma virens, which suggests that the ability to produce compounds related to destruxin and sansalvamide is widespread.

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

    Science.gov (United States)

    Bakal, Tomas; Goo, Kian-Sim; Najmanova, Lucie; Plhackova, Kamila; Kadlcik, Stanislav; Ulanova, Dana

    2015-11-01

    In the biosynthesis of diverse natural bioactive products the adenylation domains (ADs) of nonribosomal peptide synthetases select specific precursors from the cellular pool and activate them for further incorporation into the scaffold of the final compound. Therefore, the drug discovery programs employing PCR-based screening studies of microbial collections or metagenomic libraries often use AD-coding genes as markers of relevant biosynthetic gene clusters. However, due to significant sequence diversity of ADs, the conventional approach using only one primer pair in a single screening experiment could be insufficient for maximal coverage of AD abundance. In this study, the widely used primer pair A3F/A7R was compared with the newly designed aa194F/aa413R one by 454 pyrosequencing of two sets of actinomycete strains from highly dissimilar environments: subseafloor sediments and forest soil. Individually, none of the primer pairs was able to cover the overall diversity of ADs. However, due to slightly shifted specificity of the primer pairs, the total number and diversity of identified ADs were noticeably extended when both primer pairs were used in a single assay. Additionally, the efficiency of AD detection by different primer combinations was confirmed on the model of Salinispora tropica genomic DNA of known sequence.

  9. Ces locus embedded proteins control the non-ribosomal synthesis of the cereulide toxin in emetic Bacillus cereus on multiple levels

    Directory of Open Access Journals (Sweden)

    Genia eLücking

    2015-10-01

    Full Text Available The emetic toxin cereulide produced by Bacillus cereus is synthesized by the modular enzyme complex Ces that is encoded on a pXO1-like mega-plasmid. To decipher the role of the genes adjacent to the structural genes cesA/cesB, coding for the nonribosomal peptide synthetase (NRPS, gene inactivation- and overexpression mutants of the emetic strain F4810/72 were constructed and their impact on cereulide biosynthesis was assessed. The hydrolase CesH turned out to be a part of the complex regulatory network controlling cereulide synthesis on a transcriptional Level, while the ABC transporter CesCD was found to be essential for post-translational control of cereulide synthesis. Using a gene inactivation approach, we show that the NRPS activating function of the phosphopantetheinyl transferase (PPtase embedded in the ces locus was complemented by a chromosomally encoded Sfp-like PPtase, representing an interesting example for the functional interaction between a plasmid encoded NRPS and a chromosomally encoded activation enzyme. In summary, our results highlight the complexity of cereulide biosynthesis and reveal multiple levels of toxin formation control. ces operon internal genes were shown to play a pivotal role by acting at different levels of toxin production, thus complementing the action of the chromosomal key transcriptional regulators AbrB and CodY.

  10. Molecular genetic analysis reveals that a nonribosomal peptide synthetase-like (NRPS-like) gene in Aspergillus nidulans is responsible for microperfuranone biosynthesis.

    Science.gov (United States)

    Yeh, Hsu-Hua; Chiang, Yi-Ming; Entwistle, Ruth; Ahuja, Manmeet; Lee, Kuan-Han; Bruno, Kenneth S; Wu, Tung-Kung; Oakley, Berl R; Wang, Clay C C

    2012-11-01

    Genome sequencing of Aspergillus species including Aspergillus nidulans has revealed that there are far more secondary metabolite biosynthetic gene clusters than secondary metabolites isolated from these organisms. This implies that these organisms can produce additional secondary metabolites, which have not yet been elucidated. The A. nidulans genome contains 12 nonribosomal peptide synthetase (NRPS), one hybrid polyketide synthase/NRPS, and 14 NRPS-like genes. The only NRPS-like gene in A. nidulans with a known product is tdiA, which is involved in terrequinone A biosynthesis. To attempt to identify the products of these NRPS-like genes, we replaced the native promoters of the NRPS-like genes with the inducible alcohol dehydrogenase (alcA) promoter. Our results demonstrated that induction of the single NRPS-like gene AN3396.4 led to the enhanced production of microperfuranone. Furthermore, heterologous expression of AN3396.4 in Aspergillus niger confirmed that only one NRPS-like gene, AN3396.4, is necessary for the production of microperfuranone.

  11. Enzymatic assembly of epothilones: the EpoC subunit and reconstitution of the EpoA-ACP/B/C polyketide and nonribosomal peptide interfaces.

    Science.gov (United States)

    O'Connor, Sarah E; Chen, Huawei; Walsh, Christopher T

    2002-04-30

    The biosynthesis of epothilones, a family of hybrid polyketide (PK)/nonribosomal peptide (NRP) antitumor agents, provides an ideal system to study a hybrid PK/NRP natural product with significant biomedical value. Here the third enzyme involved in epothilone production, the five domain 195 kDa polyketide synthase (PKS) EpoC protein, has been expressed and purified from Escherichia coli. EpoC was combined with the first two enzymes of the epothilone biosynthesis pathway, the acyl carrier protein (ACP) domain of EpoA and EpoB, to reconstitute the early steps in epothilone biosynthesis. The acyltransferase (AT) domain of EpoC transfers the methylmalonyl moiety from methylmalonyl-CoA to the holo HS-acyl carrier protein (ACP) in an autoacylation reaction. The ketosynthase (KS) domain of EpoC decarboxylates the methylmalonyl-S-EpoC acyl enzyme to generate the carbon nucleophile that reacts with methylthiazolylcarboxyl-S-EpoB. The resulting condensation product can be reduced in the presence of NADPH by the ketoreductase (KR) domain of EpoC and then dehydrated by the dehydratase (DH) domain to produce the methylthiazolylmethylacrylyl-S-EpoC acyl enzyme intermediate that serves as the acyl donor for subsequent elongation of the epothilone chain. The acetyl-CoA donor can be replaced with propionyl-CoA, isobutyryl-CoA, and benzoyl-CoA and the acyl chains accepted by both EpoB and EpoC subunits to produce ethyl-, isopropyl-, and phenylthiazolylmethylacrylyl-S-EpoC acyl enzyme intermediates, suggesting that future combinatorial biosynthetic variations in epothilone assembly may be feasible. These results demonstrate in vitro reconstitution of both the PKS/NRPS interface (EpoA-ACP/B) and the NRPS/PKS interface (EpoB/C) in the assembly line for this antitumor natural product.

  12. 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,…

  13. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    the standard enzyme-linked immunoassay (ELISA) test. Design. Prospective ... African origin,' since most of the available commercial tests are not manufactured in ... specimens (plasma or whole blood), and it has a long shelf life. Study sites.

  14. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    Mogensen CE. Combined high blood pressure and glucose in type 2 diabetes: double .... relevant exercise-induced tachycardia originating in the right yentricular ..... of pain, and considers the physical, pharmacological and psychological in-.

  15. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    abundant component of the human leucocyte population and although essential for host .... ORIGINAL ARTICLES kinase,'6 an important enzyme in the signal transduction ... neutrophils from two different subjects. FMLP (!-)and PAF (¥).

  16. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    ORIGINAL ARTICLES. Cannabis and other drug use among trauma patients in three ... Department of Psychology, Stellenbosch University, W Cape. Charles D H ..... of cannabis and methaqualone on cognitive or psychomotor skills, including.

  17. Original pedagogues

    DEFF Research Database (Denmark)

    Schmidt, Christina Haandbæk

    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......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...... of pedagogues and in everyday life in daycare facilities. The competence term includes at least two discourses of interest; a pedagogical competence discourse and a political jurisdiction discourse which forms a distention between authenticity and competence. In order that pedagogues may regain their autonomy I...

  18. 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...

  19. Cultural Originality

    African Journals Online (AJOL)

    because it addresses, from a different direction, the problem that Mafeje has referred to as ... of originality for the concept of alterity (or difference) and endorse it rather ... ment with difficult problems, the discipline's characteristic methods are enor- ..... Each case study performs two functions in the argument: (i) it builds the.

  20. Original Research

    African Journals Online (AJOL)

    Landraces by Combined Analysis of Molecular & Phenotypic Data. Negash Geleta1* .... Studies based on solely phenotypic traits variations may not be ..... origin while between regions dissimilarity ranged from 0.51 ... indigenous evolution of this species. Therefore, .... development and use of microsatellite markers for.

  1. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    treatment with causlics that left scars worse that the original lesions. Even then the ... large numbers from a disease that spread by direct contact.' Suetonius mentions 30 ..... appeared in the 16th century and cholera even later.1•.21. Epidemic ...

  2. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    Recently, good agreement was demonstrated. between the ... intakes with measured 24-hour energy expenditure and urinary ... basis of a subject's inability to answer three questions relating ... 21 subjects (11 women; 10 men) was drawn from the original ... Research Committee of the University of Cape Town and Allied.

  3. Article original

    African Journals Online (AJOL)

    ebutamanya

    12 févr. 2015 ... décrire les facteurs associés. Méthodes: ... Bien que chaque comorbidité soit un facteur aggravant potentiel de ... sur la progression de l'infection à VIH. ..... pesanteurs sociales source de stigmatisation à l'origine de difficultés.

  4. MEDIAMUSIC ORIGINS

    Directory of Open Access Journals (Sweden)

    Chernyshov Alexander V.

    2012-12-01

    Full Text Available The article investigates the origins of music in electronic regular broadcasting, which conditions have appeared in the XIX century. They stand out in the "telephone concerts", "phonograph concerts" and the proto-sound films (T.Edison, W.Dickson, Ch.Pathé, O.Messter. In the early twentieth century, a clear prototype of mediamusic playing by the music of "silent" films, which has been divided on the on-screen and offscreen sound layers, the method of compilation, the basics of synchronization between musical sound and off-music montage-structures. In addition, the origins of music of electronic mass media can be regarded as attempts to understand the "musical" noise features, which subsequently materialize in the phenomenon of "noisemusic" of media audio-score (L.Russolo, Ars.Avraamov, D.Vertov, W.Ruttmann, N.Voinov, P.Schaeffer. Are considered Russian, European and North American experiences.

  5. Mitochondrial origins.

    OpenAIRE

    Yang, D.; Oyaizu, Y; Oyaizu, H; Olsen, G J; Woese, C R

    1985-01-01

    The 16S ribosomal RNA sequences from Agrobacterium tumefaciens and Pseudomonas testosteroni have been determined to further delimit the origin of the endosymbiont that gave rise to the mitochondrion. These two prokaryotes represent the alpha and beta subdivisions, respectively, of the so-called purple bacteria. The endosymbiont that gave rise to the mitochondrion belonged to the alpha subdivision, a group that also contains the rhizobacteria, the agrobacteria, and the rickettsias--all prokary...

  6. 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.

  7. Endogenous cross-talk of fungal metabolites.

    Directory of Open Access Journals (Sweden)

    Kevin J Sheridan

    2015-01-01

    Full Text Available Non-ribosomal peptide synthesis in fungi requires a ready supply of proteogenic and non-proteogenic amino acids which are subsequently incorporated into the nascent non-ribosomal peptide via a thiotemplate mechanism catalysed by non-ribosomal peptide synthetases. Substrate amino acids can be modified prior to or during incorporation into the non-ribosomal peptide, or following incorporation into an early stage amino acid-containing biosynthetic intermediate. These post-incorporation modifications involve a range of additional enzymatic activities including but not exclusively, monooxygenases, methyltransferases, epimerases, oxidoreductases and glutathione transferases which are essential to effect biosynthesis of the final non-ribosomal peptide. Likewise, polyketide biosynthesis is directly by polyketide synthase megaenzymes and cluster-encoded ancilliary decorating enzymes. Additionally, a suite of additional primary metabolites, for example: CoA, acetyl CoA, S-adenosylmethionine, glutathione, NADPH, malonyl CoA and molecular oxygen, amongst others are required for non-ribosomal peptide and polyketide synthesis. Clearly these processes must involve exquisite orchestration to facilitate the simultaneous biosynthesis of different types of non-ribosomal peptides, polyketides, and related metabolites requiring identical or similar biosynthetic precursors or co-factors. Moreover, the near identical structures of many natural products within a given family (e.g., ergot alkaloids, along with localization to similar regions within fungi (e.g., conidia suggests that cross-talk may exist, in terms of biosynthesis and functionality. Finally, we speculate if certain biosynthetic steps involved in non-ribosomal peptide and polyketide synthesis play a role in cellular protection or environmental adaptation, and wonder if these enzymatic reactions are of equivalent importance to the actual biosynthesis of the final metabolite.

  8. Homocysteine Editing, Thioester Chemistry, Coenzyme A, and the Origin of Coded Peptide Synthesis †.

    Science.gov (United States)

    Jakubowski, Hieronim

    2017-02-09

    Aminoacyl-tRNA synthetases (AARSs) have evolved "quality control" mechanisms which prevent tRNA aminoacylation with non-protein amino acids, such as homocysteine, homoserine, and ornithine, and thus their access to the Genetic Code. Of the ten AARSs that possess editing function, five edit homocysteine: Class I MetRS, ValRS, IleRS, LeuRS, and Class II LysRS. Studies of their editing function reveal that catalytic modules of these AARSs have a thiol-binding site that confers the ability to catalyze the aminoacylation of coenzyme A, pantetheine, and other thiols. Other AARSs also catalyze aminoacyl-thioester synthesis. Amino acid selectivity of AARSs in the aminoacyl thioesters formation reaction is relaxed, characteristic of primitive amino acid activation systems that may have originated in the Thioester World. With homocysteine and cysteine as thiol substrates, AARSs support peptide bond synthesis. Evolutionary origin of these activities is revealed by genomic comparisons, which show that AARSs are structurally related to proteins involved in coenzyme A/sulfur metabolism and non-coded peptide bond synthesis. These findings suggest that the extant AARSs descended from ancestral forms that were involved in non-coded Thioester-dependent peptide synthesis, functionally similar to the present-day non-ribosomal peptide synthetases.

  9. Homocysteine Editing, Thioester Chemistry, Coenzyme A, and the Origin of Coded Peptide Synthesis †

    Directory of Open Access Journals (Sweden)

    Hieronim Jakubowski

    2017-02-01

    Full Text Available Aminoacyl-tRNA synthetases (AARSs have evolved “quality control” mechanisms which prevent tRNA aminoacylation with non-protein amino acids, such as homocysteine, homoserine, and ornithine, and thus their access to the Genetic Code. Of the ten AARSs that possess editing function, five edit homocysteine: Class I MetRS, ValRS, IleRS, LeuRS, and Class II LysRS. Studies of their editing function reveal that catalytic modules of these AARSs have a thiol-binding site that confers the ability to catalyze the aminoacylation of coenzyme A, pantetheine, and other thiols. Other AARSs also catalyze aminoacyl-thioester synthesis. Amino acid selectivity of AARSs in the aminoacyl thioesters formation reaction is relaxed, characteristic of primitive amino acid activation systems that may have originated in the Thioester World. With homocysteine and cysteine as thiol substrates, AARSs support peptide bond synthesis. Evolutionary origin of these activities is revealed by genomic comparisons, which show that AARSs are structurally related to proteins involved in coenzyme A/sulfur metabolism and non-coded peptide bond synthesis. These findings suggest that the extant AARSs descended from ancestral forms that were involved in non-coded Thioester-dependent peptide synthesis, functionally similar to the present-day non-ribosomal peptide synthetases.

  10. The Origin(s) of Whales

    Science.gov (United States)

    Uhen, Mark D.

    2010-05-01

    Whales are first found in the fossil record approximately 52.5 million years ago (Mya) during the early Eocene in Indo-Pakistan. Our knowledge of early and middle Eocene whales has increased dramatically during the past three decades to the point where hypotheses of whale origins can be supported with a great deal of evidence from paleontology, anatomy, stratigraphy, and molecular biology. Fossils also provide preserved evidence of behavior and habitats, allowing the reconstruction of the modes of life of these semiaquatic animals during their transition from land to sea. Modern whales originated from ancient whales at or near the Eocene/Oligocene boundary, approximately 33.7 Mya. During the Oligocene, ancient whales coexisted with early baleen whales and early toothed whales. By the end of the Miocene, most modern families had originated, and most archaic forms had gone extinct. Whale diversity peaked in the late middle Miocene and fell thereafter toward the Recent, yielding our depauperate modern whale fauna.

  11. Multiple origins of life

    Science.gov (United States)

    Raup, D. M.; Valentine, J. W.

    1983-01-01

    There is some indication that life may have originated readily under primitive earth conditions. If there were multiple origins of life, the result could have been a polyphyletic biota today. Using simple stochastic models for diversification and extinction, we conclude: (1) the probability of survival of life is low unless there are multiple origins, and (2) given survival of life and given as many as 10 independent origins of life, the odds are that all but one would have gone extinct, yielding the monophyletic biota we have now. The fact of the survival of our particular form of life does not imply that it was unique or superior.

  12. Chemical Origins of Life

    Science.gov (United States)

    Fox, J. Lawrence

    1972-01-01

    Reviews ideas and evidence bearing on the origin of life. Shows that evidence to support modifications of Oparin's theories of the origin of biological constituents from inorganic materials is accumulating, and that the necessary components are readily obtained from the simple gases found in the universe. (AL)

  13. Chemical Origins of Life

    Science.gov (United States)

    Fox, J. Lawrence

    1972-01-01

    Reviews ideas and evidence bearing on the origin of life. Shows that evidence to support modifications of Oparin's theories of the origin of biological constituents from inorganic materials is accumulating, and that the necessary components are readily obtained from the simple gases found in the universe. (AL)

  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. ·: ORIGINAL ARTICLES

    African Journals Online (AJOL)

    ORIGINAL ARTICLES educating the children and their families about optimal asthma ... underlies the need for doctors to improve their communication skills with both ..... Diagnostic and therapeutic strategies should take this into consideration.

  16. [Hypotension from endocrine origin].

    Science.gov (United States)

    Vantyghem, Marie-Christine; Douillard, Claire; Balavoine, Anne-Sophie

    2012-11-01

    Hypotension is defined by a low blood pressure either permanently or only in upright posture (orthostatic hypotension). In contrast to hypertension, there is no threshold defining hypotension. The occurrence of symptoms for systolic and diastolic measurements respectively below 90 and 60 mm Hg establishes the diagnosis. Every acute hypotensive event should suggest shock, adrenal failure or an iatrogenic cause. Chronic hypotension from endocrine origin may be linked to adrenal failure from adrenal or central origin, isolated hypoaldosteronism, pseudohypoaldosteronism, pheochromocytoma, neuro-endocrine tumors (carcinoïd syndrome) or diabetic dysautonomia. Hypotension related to hypoaldosteronism associates low blood sodium and above all high blood potassium levels. They are generally classified according to their primary (hyperreninism) or secondary (hyporeninism) adrenal origin. Isolated primary hypoaldosteronisms are rare in adults (intensive care unit, selective injury of the glomerulosa area) and in children (aldosterone synthase deficiency). Isolated secondary hypoaldosteronism is related to mellitus diabetes complicated with dysautonomia, kidney failure, age, iatrogenic factors, and HIV infections. In both cases, they can be associated to glucocorticoid insufficiency from primary adrenal origin (adrenal failure of various origins with hyperreninism, among which congenital 21 hydroxylase deficiency with salt loss) or from central origin (hypopituitarism with hypo-reninism). Pseudohypoaldosteronisms are linked to congenital (type 1 pseudohypoaldosteronism) or acquired states of resistance to aldosterone. Acquired salt losses from enteric (total colectomy with ileostomy) or renal (interstitial nephropathy, Bartter and Gitelman syndromes…) origin might be responsible for hypotension and are associated with hyperreninism-hyperaldosteronism. Hypotension is a rare manifestation of pheochromocytomas, especially during surgical removal when the patient has not been

  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. Origins Space Telescope

    Science.gov (United States)

    Cooray, Asantha R.; Origins Space Telescope Study Team

    2017-01-01

    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. I will summarize the OST STDT, mission design and instruments, key science drivers, and the study plan over the next two years.

  19. The Origin of Life

    Science.gov (United States)

    Hodson, D.

    1975-01-01

    Presents an outline of lectures given on this topic to British secondary students. Man's various ideas about the origin of life are included in three categories: those that consider life to have been created by a Divine Being; those that consider life to have developed from non-living matter; and those that consider life to be eternal. (MLH)

  20. 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...

  1. Symbiotic Origin of Aging.

    Science.gov (United States)

    Greenberg, Edward F; Vatolin, Sergei

    2017-09-25

    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.

  2. Fever of unknown origin

    NARCIS (Netherlands)

    Mulders-Manders, C.; Simon, A.; Bleeker-Rovers, C.P.

    2015-01-01

    More than 50 years after the first definition of fever of unknown origin (FUO), it still remains a diagnostic challenge. Evaluation starts with the identification of potential diagnostic clues (PDCs), which should guide further investigations. In the absence of PDCs a standardised diagnostic

  3. 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…

  4. 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

  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. On the origin of 3-methylglutaconic acid in disorders of mitochondrial energy metabolism.

    Science.gov (United States)

    Ikon, Nikita; Ryan, Robert O

    2016-09-01

    3-methylglutaconic acid (3MGA)-uria occurs in numerous inborn errors of metabolism (IEM) associated with compromised mitochondrial energy metabolism. This organic acid arises from thioester cleavage of 3-methylglutaconyl CoA (3MG CoA), an intermediate in leucine catabolism. In individuals harboring mutations in 3MG CoA hydratase (i.e., primary 3MGA-uria), dietary leucine is the source of 3MGA. In secondary 3MGA-uria, however, no leucine metabolism defects have been reported. While others have suggested 3MGA arises from aberrant isoprenoid shunting from cytosol to mitochondria, an alternative route posits that 3MG CoA arises in three steps from mitochondrial acetyl CoA. Support for this biosynthetic route in IEMs is seen by its regulated occurrence in microorganisms. The fungus, Ustilago maydis, the myxobacterium, Myxococcus xanthus and the marine cyanobacterium, Lyngbya majuscule, generate 3MG CoA (or acyl carrier protein derivative) in the biosynthesis of iron chelating siderophores, iso-odd chain fatty acids and polyketide/nonribosomal peptide products, respectively. The existence of this biosynthetic machinery in these organisms supports a model wherein, under conditions of mitochondrial dysfunction, accumulation of acetyl CoA in the inner mitochondrial space as a result of inefficient fuel utilization drives de novo synthesis of 3MG CoA. Since humans lack the downstream biosynthetic capability of the organisms mentioned above, as 3MG CoA levels rise, thioester hydrolysis yields 3MGA, which is excreted in urine as unspent fuel. Understanding the metabolic origins of 3MGA may increase its utility as a biomarker.

  7. 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...... as both a scientific and political site of interest more recently through the study of population genetics in both humans and non-humans. This article explores the ways in which genetics and notions of ‘authentic’, ‘indigenous’, and ‘endemic’ have become intertwined with everyday practices in research....... 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....

  8. The Origins of Art

    Directory of Open Access Journals (Sweden)

    Aleksandre P. Lobodanov

    2015-12-01

    Full Text Available The origins of artistic activities or rather art, and in recent decades the processing and consolidation of a new field in art history, art semiotics, are grouped together in the semiotic systems of applied and non-applied arts.In this paper, in particular, an analysis is made of the non-applied arts, in which non-verbal signs are used to express the form of human thought.The discussion focuses on the origins of non-applied arts, the image-forming process, the psychology of perception, the perception of sound and reproduction of sounds, the development of music and the development of dance in their entirety, as an expression of the inner condition that influences the body through movement: it thus provides a valuable contribution to the study of the non-applied arts.

  9. Thermodynamic Origin of Life

    CERN Document Server

    Michaelian, K

    2009-01-01

    Understanding the thermodynamic function of life may shed light on its origin. Out of equilibrium structuring in space and time is contingent on continuous entropy production. Entropy production is a measure of the rate of the natural tendency of Nature to explore all available microstates. The process producing the greatest amount of entropy in the biosphere is the absorption and transformation of sunlight, leading to the transpiration of water by plants and cyanobacteria. Here we hypothesize that life began, and exists today, as a dynamic catalyst for the absorption and transformation of sunlight into heat, which could then be efficiently harvested by the water cycle, hurricanes, and ocean and wind currents. RNA and DNA are the most efficient of all known molecules for absorbing the ultraviolet light that could have penetrated the dense early atmosphere, and are extremely rapid in transforming this light into heat that can be readily absorbed by liquid water. The origin and evolution of life was thus driven...

  10. Origin of Life

    CERN Document Server

    Lal, Ashwini Kumar

    2009-01-01

    The evolution of life has been a big enigma despite rapid advancements in the field of astrobiology, astrophysics and genetics in recent years. The answer to this puzzle has been as mindboggling as the riddle relating to evolution of Universe itself. Despite the fact that panspermia has gained considerable support as a viable explanation for origin of life on the Earth and elsewhere in the Universe, the issue however, remains far from a tangible solution. This paper examines the various prevailing hypotheses regarding origin of life like abiogenesis, RNA(ribonucleic acid) world, iron-sulphur world, panspermia, and concludes that delivery of life-bearing organic molecules by the comets in the early epoch of the Earth alone possibly was not responsible for kickstarting the process of evolution of life on our planet.

  11. The origin of comets

    Science.gov (United States)

    Bailey, M. E.; Clube, S. V. M.; Napier, W. M.

    Theories of the nature and origin of comets are discussed in a historical review covering the period from ancient times to the present. Consideration is given to the ancient controversy as to the atmospheric or celestial nature of comets, Renaissance theories of comet orbits, superstitions regarding the effects of comets, Kant's (1755) theory of solar-system origin, the nineteenth-century discovery of the relationship between comets and meteor showers, and the continuing solar-system/interstellar debate. Oort's (1950) model of a comet swarm surrounding the solar system is examined in detail; arguments advanced to explain the formation of comets within this model are summarized; and the question of cometary catastrophism is addressed.

  12. Toothache of cardiac origin.

    Science.gov (United States)

    Kreiner, M; Okeson, J P

    1999-01-01

    Pain referred to the orofacial structures can sometimes be a diagnostic challenge for the clinician. In some instances, a patient may complain of tooth pain that is completely unrelated to any dental source. This poses a diagnostic and therapeutic problem for the dentist. Cardiac pain most commonly radiates to the left arm, shoulder, neck, and face. In rare instances, angina pectoris may present as dental pain. When this occurs, an improper diagnosis frequently leads to unnecessary dental treatment or, more significantly, a delay of proper treatment. This delay may result in the patient experiencing an acute myocardial infarction. It is the dentist's responsibility to establish a proper diagnosis so that the treatment will be directed toward the source of pain and not to the site of pain. This article reviews the literature concerning referred pain of cardiac origin and presents a case report of toothache of cardiac origin.

  13. Thermodynamic Origin of Life

    OpenAIRE

    Michaelian, K.

    2009-01-01

    Understanding the thermodynamic function of life may shed light on its origin. Life, as are all irreversible processes, is contingent on entropy production. Entropy production is a measure of the rate of the tendency of Nature to explore available microstates. The most important irreversible process generating entropy in the biosphere, and thus facilitating this exploration, is the absorption and transformation of sunlight into heat. Here we hypothesize that life began, and persists today, as...

  14. Conscientiousness: Origins in Childhood?

    OpenAIRE

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

    2012-01-01

    In this review, we evaluate developmental and personality research with the aim of determining if 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 self-regulation, academic motivation, and internalized compliance/internalization of standards. Based on the accumulated body of evidence, we conclude that self...

  15. 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.

  16. DNA replication origins in archaea

    OpenAIRE

    Zhenfang eWu; Jingfang eLiu; Haibo eYang; Hua eXiang

    2014-01-01

    DNA replication initiation, which starts at specific chromosomal site (known as replication origins), is the key regulatory stage of chromosome replication. Archaea, the third domain of life, use a single or multiple origin(s) to initiate replication of their circular chromosomes. The basic structure of replication origins is conserved among archaea, typically including an AT-rich unwinding region flanked by several conserved repeats (origin recognition box, ORB) that are located adjacent to ...

  17. [Fever of unknown origin].

    Science.gov (United States)

    Salzberger, B; Müller-Schilling, M; Fleck, M

    2013-04-01

    Fever of unknown origin (FUO) is defined as sustained unexplained fever despite intensive diagnostic evaluation and represents a particular diagnostic challenge. It can be classified into different categories, e.g. classical, nosocomial, neutropenic and HIV-associated FUO, which is based on the patient-specific clinical and immunological situation. Infections, malignant diseases and non-infectious inflammatory diseases have to be considered as the most important causes of FUO; however, no definitive diagnosis can be established in a substantial number of FUO patients despite an extensive diagnostic work-up. The present review focuses on the important diagnostic aspects as well as therapeutic options in FUO patients.

  18. Origin of Tektites.

    Science.gov (United States)

    O'keefe, J A; Shute, B E

    1963-03-29

    A comet of the size recently postulated by H. C. Urey would leave a large crater. It is shown, from aerodynamic theory, from observations of distribution around terrestrial impact craters, and from experimental nuclear explosions, that the observed distribution of tektites cannot be the result of impact on the earth, whether cometary or meteoritic. It is further shown, from aerodynamic theory, from observation of a meteor shower, and from study of the breakup of artificial satellites, that the distribution of tektites can be accounted for as a result of fusion stripping of a satellite, as originally suggested by Suess.

  19. Origin of earth's moon

    Science.gov (United States)

    Wood, J. A.

    1977-01-01

    The major geochemical properties of the moon are briefly considered along with the significant facts of the moon's geologic history, and then the three current hypotheses regarding the moon's origin, namely, fission, capture, and binary accretion, are reviewed. The individual merits and improbabilities associated with each mechanism are taken into consideration. Special attention is given to the binary accretion model as the most promising one. In the variants of this model, of crucial importance is the nature of the more general hypothesis assumed for planetary formation from the solar nebula. The two main models differ considerably in the amount of chemical fractionation they allow to accompany planetary formation.

  20. The Origins of Neuroticism.

    Science.gov (United States)

    Barlow, David H; Ellard, Kristen K; Sauer-Zavala, Shannon; Bullis, Jacqueline R; Carl, Jenna R

    2014-09-01

    In this article, we provide a fresh perspective on the developmental origins of neuroticism--a dimension of temperament marked by elevated stress reactivity resulting in the frequent experience of negative emotions. This negative affectivity is accompanied by a pervasive perception that the world is a dangerous and threatening place, along with beliefs about one's inability to manage or cope with challenging events. Historically, neuroticism has been viewed as a stable, genetically based trait. However, recent understanding of ongoing gene-environment interactions that occur throughout the life span suggests there may be a more complex and dynamic etiology. Thus, the purpose of this article is to offer a theory for understanding the development of neuroticism that integrates genetic, neurobiological, and environmental contributions to this trait. Given the strong correlation between neuroticism and the development of negative health outcomes--most notably, the full range of anxiety and mood disorders--an enhanced understanding of how neuroticism originates has implications for the treatment and prevention of a broad range of pathologies and, perhaps, even for the prevention of neuroticism itself.

  1. First molecules, biological chirality, origin(s) of life.

    Science.gov (United States)

    Caglioti, Luciano; Micskei, Károly; Pályi, Gyula

    2011-01-01

    Origin(s) of biological chirality appear(s) to be intimately connected to origin(s) of life. Prebiotic evolution toward these important turning points can be traced back to single chiral molecules. These can be small (monomeric) units as amino acids or monosaccharides or oligomers as oligo-RNA type molecules. Earlier speculations about these two kinds of entries to biological chirality are critically reviewed.

  2. Origins of hydration lubrication.

    Science.gov (United States)

    Ma, Liran; Gaisinskaya-Kipnis, Anastasia; Kampf, Nir; Klein, Jacob

    2015-01-14

    Why is friction in healthy hips and knees so low? Hydration lubrication, according to which hydration shells surrounding charges act as lubricating elements in boundary layers (including those coating cartilage in joints), has been invoked to account for the extremely low sliding friction between surfaces in aqueous media, but not well understood. Here we report the direct determination of energy dissipation within such sheared hydration shells. By trapping hydrated ions in a 0.4-1 nm gap between atomically smooth charged surfaces as they slide past each other, we are able to separate the dissipation modes of the friction and, in particular, identify the viscous losses in the subnanometre hydration shells. Our results shed light on the origins of hydration lubrication, with potential implications both for aqueous boundary lubricants and for biolubrication.

  3. The origin of humor.

    Science.gov (United States)

    Howe, N E

    2002-09-01

    Humor is spread throughout every culture on earth and occupies a large portion of our literature and social interaction. It is so deeply rooted in our culture that it may be a defining characteristic of our species. Yet there has been comparatively little effort to understand its origin. According to the Accepted Theory of Humor all jokes begin with a buildup of tension while an initial paradigm is formed. When the punch line occurs the subject must realign his thinking to accommodate the differences between the initial paradigm and the sudden burst of new information. The Mind Reading Hypothesis extends the accepted theory of humor to include a relationship between the observer and the subject of the humor. The actual source of amusement is the observation of the resolution in the mind of the subject of the collision between old perception and new reality.

  4. Origins of Stellar Halos

    Science.gov (United States)

    Johnston, Kathryn V.

    2016-08-01

    This contribution reviews ideas about the origins of stellar halos. It includes discussion of the theoretical understanding of and observational evidence for stellar populations formed ``in situ'' (meaning formed in orbits close to their current ones), ``kicked-out'' (meaning formed in the inner galaxy in orbits unlike their current ones) and ``accreted'' (meaning formed in a dark matter halo other than the one they currently occupy). At this point there is general agreement that a significant fraction of any stellar halo population is likely ``accreted''. There is modest evidence for the presence of a ``kicked-out'' population around both the Milky Way and M31. Our theoretical understanding of and the observational evidence for an ``in situ'' population are less clear.

  5. Original and Derived Judgment

    DEFF Research Database (Denmark)

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

    Recent work links entrepreneurship to the economic theory of firm using the Knightian concept of entrepreneurship as judgment. When judgment is complementary to other as-sets, and these assets or their services are traded in well-functioning markets, it makes sense for entrepreneurs to hire labor...... 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...... agreements, means of evaluating perform-ance, and so on — can be designed to encourage forms of proxy-entrepreneurship that increase firm value while discouraging actions that destroy value. Building on key ideas from the entrepreneurship literature, Austrian economics, and the economic theory of the firm we...

  6. Original and Derived Judgment

    DEFF Research Database (Denmark)

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

    2007-01-01

    Recent work links entrepreneurship to the economic theory of the firm, using the concept of entrepreneurship as judgment introduced by Frank Knight. When judgment is complementary to other assets, it makes sense for entrepreneurs to hire labour and to own assets. The entrepreneur's role, then......, is to arrange or organize the human and capital assets under his or her control. We extend this Knightian concept of the firm by developing a theory of delegation under Knightian uncetainty. What we call original judgment belongs exclusively to owners, but owners may delegate a wide range of decision rights...... be designed to encourage forms of proxy entrepreneurship that increase firm value while discouraging actions that destroy value. Building on key ideas from the entrepreneurship literature, Austrian economics and the economic theory of the firm, we develop a framework for analysing the trade-off between...

  7. Mechanical origin of aftershocks.

    Science.gov (United States)

    Lippiello, E; Giacco, F; Marzocchi, W; Godano, C; de Arcangelis, L

    2015-10-26

    Aftershocks are the most striking evidence of earthquake interactions and the physical mechanisms at the origin of their occurrence are still intensively debated. Novel insights stem from recent results on the influence of the faulting style on the aftershock organisation in magnitude and time. Our study shows that the size of the aftershock zone depends on the fault geometry. We find that positive correlations among parameters controlling aftershock occurrence in time, energy and space are a stable feature of seismicity independently of magnitude range and geographic areas. We explain the ensemble of experimental findings by means of a description of the Earth Crust as an heterogeneous elastic medium coupled with a Maxwell viscoelastic asthenosphere. Our results show that heterogeneous stress distribution in an elastic layer combined with a coupling to a viscous flow are sufficient ingredients to describe the physics of aftershock triggering.

  8. Original and Derived Judgment

    DEFF Research Database (Denmark)

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

    Recent work links entrepreneurship to the economic theory of firm using the Knightian concept of entrepreneurship as judgment. When judgment is complementary to other as-sets, and these assets or their services are traded in well-functioning markets, it makes sense for entrepreneurs to hire labor...... 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...... may delegate a wide range of decision rights to subordinates, who exercise derived judgment. We call these employees "proxy-entrepreneurs," and ask how the firm's or-ganizational structure — its formal and informal systems of rewards and punishments, rules for settling disputes and renegotiating...

  9. Anaerobic Origin of Ergothioneine.

    Science.gov (United States)

    Burn, Reto; Misson, Laëtitia; Meury, Marcel; Seebeck, Florian P

    2017-10-02

    Ergothioneine is a sulfur metabolite that occurs in microorganisms, fungi, plants, and animals. The physiological function of ergothioneine is not clear. In recent years broad scientific consensus has formed around the idea that cellular ergothioneine primarily protects against reactive oxygen species. Herein we provide evidence that this focus on oxygen chemistry may be too narrow. We describe two enzymes from the strictly anaerobic green sulfur bacterium Chlorobium limicola that mediate oxygen-independent biosynthesis of ergothioneine. This anoxic origin suggests that ergothioneine is also important for oxygen-independent life. Furthermore, one of the discovered ergothioneine biosynthetic enzymes provides the first example of a rhodanese-like enzyme that transfers sulfur to non-activated carbon. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Fever of unknown origin.

    Science.gov (United States)

    Mulders-Manders, Catharina; Simon, Anna; Bleeker-Rovers, Chantal

    2015-06-01

    More than 50 years after the first definition of fever of unknown origin (FUO), it still remains a diagnostic challenge. Evaluation starts with the identification of potential diagnostic clues (PDCs), which should guide further investigations. In the absence of PDCs a standardised diagnostic protocol should be followed with PET-CT as the imaging technique of first choice. Even with a standardised protocol, in a large proportion of patients from western countries the cause for FUO cannot be identified. The treatment of FUO is guided by the final diagnosis, but when no cause is found, antipyretic drugs can be prescribed. Corticosteroids should be avoided in the absence of a diagnosis, especially at an early stage. The prognosis of FUO is determined by the underlying cause. The majority of patients with unexplained FUO will eventually show spontaneous remission of fever. We describe the definition, diagnostic workup, causes and treatment of FUO. © Royal College of Physicians 2015. All rights reserved.

  11. The Origin of Mercury

    Science.gov (United States)

    Benz, W.; Anic, A.; Horner, J.; Whitby, J. A.

    Mercury's unusually high mean density has always been attributed to special circumstances that occurred during the formation of the planet or shortly thereafter, and due to the planet's close proximity to the Sun. The nature of these special circumstances is still being debated and several scenarios, all proposed more than 20 years ago, have been suggested. In all scenarios, the high mean density is the result of severe fractionation occurring between silicates and iron. It is the origin of this fractionation that is at the centre of the debate: is it due to differences in condensation temperature and/or in material characteristics (e.g. density, strength)? Is it because of mantle evaporation due to the close proximity to the Sun? Or is it due to the blasting off of the mantle during a giant impact?

  12. Microscopic origin of magnetoresistance

    Directory of Open Access Journals (Sweden)

    Christian Heiliger

    2006-11-01

    Full Text Available Tunneling magnetoresistance is one of the basic effects of spintronics with the potential for applications in sensors and IT, where the spin degree of freedom of electrons is exploited. Successful application requires control of the materials and processes involved on the atomic scale. To support experimental developments, predict new materials, and optimize the effect, first-principle electronic structure calculations based on density functional theory are the most powerful tool. The method gives an insight into the microscopic origin of spin-dependent tunneling. The main components of a planar tunnel junction – barrier, leads, and their interface – and their specific role for tunneling magnetoresistance are discussed for one of the standard systems, Fe/MgO/Fe.

  13. 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...

  14. 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.

  15. Origin of Prometheus Eccentricity

    Science.gov (United States)

    Rappaport, N. J.; Longaretti, P.

    2006-12-01

    A number of Saturn's small satellites, from Atlas to the coorbital satellites Janus and Epimetheus, move on orbits just outside the main rings of the planet. These satellites undergo extremely rapid resonant interaction with the rings and outward motion, strongly suggesting that they originated in Saturn's A ring. However, their eccentricities, of the order of 1/1000 are several orders of magnitude larger than what could be expected if the small satellites formed in the ring. This paper represents a first step to providing an explanation for this phenomenon, by focusing on the dynamical processes that have affected the eccentricity of Prometheus. The explanation invokes past resonances with the coorbital satellites combined with chaos due to overlapping of these resonances.

  16. The Pained Original

    Institute of Scientific and Technical Information of China (English)

    Cay Dollerup

    2002-01-01

    Arguing that, outside class-rooms, discussions on the relationship between translated product and the ‘original' do not advance our US, change according to the country of publication. Finally, the article points out that at many international organisations, most obviously so at the European Union with eleven official languages, there is a division of labour. In this division one or two versions of texts(in English or French)are used first as repositories of the negotiations and as a record of agreements, then as the source text for the ten or nine other language versions, and in the end as one of the eleven equally authoritative texts of which none can claim superiority over the others.

  17. Actinides and Life's Origins.

    Science.gov (United States)

    Adam, Zachary

    2007-12-01

    There are growing indications that life began in a radioactive beach environment. A geologic framework for the origin or support of life in a Hadean heavy mineral placer beach has been developed, based on the unique chemical properties of the lower-electronic actinides, which act as nuclear fissile and fertile fuels, radiolytic energy sources, oligomer catalysts, and coordinating ions (along with mineralogically associated lanthanides) for prototypical prebiotic homonuclear and dinuclear metalloenzymes. A four-factor nuclear reactor model was constructed to estimate how much uranium would have been required to initiate a sustainable fission reaction within a placer beach sand 4.3 billion years ago. It was calculated that about 1-8 weight percent of the sand would have to have been uraninite, depending on the weight percent, uranium enrichment, and quantity of neutron poisons present within the remaining placer minerals. Radiolysis experiments were conducted with various solvents with the use of uraniumand thorium-rich minerals (metatorbernite and monazite, respectively) as proxies for radioactive beach sand in contact with different carbon, hydrogen, oxygen, and nitrogen reactants. Radiation bombardment ranged in duration of exposure from 3 weeks to 6 months. Low levels of acetonitrile (estimated to be on the order of parts per billion in concentration) were conclusively identified in 2 setups and tentatively indicated in a 3(rd) by gas chromatography/mass spectrometry. These low levels have been interpreted within the context of a Hadean placer beach prebiotic framework to demonstrate the promise of investigating natural nuclear reactors as power production sites that might have assisted the origins of life on young rocky planets with a sufficiently differentiated crust/mantle structure. Future investigations are recommended to better quantify the complex relationships between energy release, radioactive grain size, fissionability, reactant phase, phosphorus

  18. Actinides and Life's Origins

    Science.gov (United States)

    Adam, Zachary

    2007-12-01

    There are growing indications that life began in a radioactive beach environment. A geologic framework for the origin or support of life in a Hadean heavy mineral placer beach has been developed, based on the unique chemical properties of the lower-electronic actinides, which act as nuclear fissile and fertile fuels, radiolytic energy sources, oligomer catalysts, and coordinating ions (along with mineralogically associated lanthanides) for prototypical prebiotic homonuclear and dinuclear metalloenzymes. A four-factor nuclear reactor model was constructed to estimate how much uranium would have been required to initiate a sustainable fission reaction within a placer beach sand 4.3 billion years ago. It was calculated that about 1-8 weight percent of the sand would have to have been uraninite, depending on the weight percent, uranium enrichment, and quantity of neutron poisons present within the remaining placer minerals. Radiolysis experiments were conducted with various solvents with the use of uranium- and thorium-rich minerals (metatorbernite and monazite, respectively) as proxies for radioactive beach sand in contact with different carbon, hydrogen, oxygen, and nitrogen reactants. Radiation bombardment ranged in duration of exposure from 3 weeks to 6 months. Low levels of acetonitrile (estimated to be on the order of parts per billion in concentration) were conclusively identified in 2 setups and tentatively indicated in a 3rd by gas chromatography/mass spectrometry. These low levels have been interpreted within the context of a Hadean placer beach prebiotic framework to demonstrate the promise of investigating natural nuclear reactors as power production sites that might have assisted the origins of life on young rocky planets with a sufficiently differentiated crust/mantle structure. Future investigations are recommended to better quantify the complex relationships between energy release, radioactive grain size, fissionability, reactant phase, phosphorus

  19. DHCP Origin Traceback

    Science.gov (United States)

    Majumdar, Saugat; Kulkarni, Dhananjay; Ravishankar, Chinya V.

    Imagine that the DHCP server is under attack from malicious hosts in your network. How would you know where these DHCP packets are coming from, or which path they took in the network? This paper investigates the problem of determining the origin of a DHCP packet in a network. We propose a practical method for adding a new option field that does not violate any RFC's, which we believe should be a crucial requirement while proposing any related solution. The new DHCP option will contain the ingress port and the switch MAC address. We recommend that this new option be added at the edge so that we can use the recorded value for performing traceback. The computational overhead of our solution is low, and the related network management tasks are low as well. We also address issues related to securing the field in order to maintain privacy of switch MAC addresses, fragmentation of packets, and possible attack scenarios. Our study shows that the traceback scheme is effective and practical to use in most network environments.

  20. The Cosmic Origins Spectrograph

    CERN Document Server

    Green, James C; Osterman, Steve; Ebbets, Dennis; Heap, Sara H; Linsky, Claus Leitherer Jeffrey L; Savage, Blair D; Sembach, Kenneth; Shull, J Michael; Siegmund, Oswald H W; Snow, Theodore P; Spencer, John; Stern, S Alan; Stocke, John; Welsh, Barry; Beland, Stephane; Burgh, Eric B; Danforth, Charles; France, Kevin; Keeney, Brian; McPhate, Jason; Penton, Steven V; Andrews, John; Brownsberger, Kenneth; Morse, Jon; Wilkinson, Erik

    2011-01-01

    The Cosmic Origins Spectrograph (COS) is a moderate-resolution spectrograph with unprecedented sensitivity that was installed into the Hubble Space Telescope (HST) in May 2009, during HST Servicing Mission 4 (STS-125). We present the design philosophy and summarize the key characteristics of the instrument that will be of interest to potential observers. For faint targets, with flux F_lambda ~ 1.0E10-14 ergs/s/cm2/Angstrom, COS can achieve comparable signal to noise (when compared to STIS echelle modes) in 1-2% of the observing time. This has led to a significant increase in the total data volume and data quality available to the community. For example, in the first 20 months of science operation (September 2009 - June 2011) the cumulative redshift pathlength of extragalactic sight lines sampled by COS is 9 times that sampled at moderate resolution in 19 previous years of Hubble observations. COS programs have observed 214 distinct lines of sight suitable for study of the intergalactic medium as of June 2011....

  1. Looking at our origins

    CERN Multimedia

    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

  2. Moon (Form-Origin)

    Science.gov (United States)

    Tsiapas, Elias

    2016-04-01

    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

  3. 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

  4. THE COSMIC ORIGINS SPECTROGRAPH

    Energy Technology Data Exchange (ETDEWEB)

    Green, James C.; Michael Shull, J.; Snow, Theodore P.; Stocke, John [Department of Astrophysical and Planetary Sciences, University of Colorado, 391-UCB, Boulder, CO 80309 (United States); Froning, Cynthia S.; Osterman, Steve; Beland, Stephane; Burgh, Eric B.; Danforth, Charles; France, Kevin [Center for Astrophysics and Space Astronomy, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Ebbets, Dennis [Ball Aerospace and Technologies Corp., 1600 Commerce Street, Boulder, CO 80301 (United States); Heap, Sara H. [NASA Goddard Space Flight Center, Code 681, Greenbelt, MD 20771 (United States); Leitherer, Claus; Sembach, Kenneth [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Linsky, Jeffrey L. [JILA, University of Colorado and NIST, Boulder, CO 80309-0440 (United States); Savage, Blair D. [Department of Astronomy, University of Wisconsin-Madison, 475 North Charter Street, Madison, WI 53706 (United States); Siegmund, Oswald H. W. [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Spencer, John; Alan Stern, S. [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Welsh, Barry [Space Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720 (United States); and others

    2012-01-01

    The Cosmic Origins Spectrograph (COS) is a moderate-resolution spectrograph with unprecedented sensitivity that was installed into the Hubble Space Telescope (HST) in 2009 May, during HST Servicing Mission 4 (STS-125). We present the design philosophy and summarize the key characteristics of the instrument that will be of interest to potential observers. For faint targets, with flux F{sub {lambda}} Almost-Equal-To 1.0 Multiplication-Sign 10{sup -14} erg cm{sup -2} s{sup -1} A{sup -1}, COS can achieve comparable signal to noise (when compared to Space Telescope Imaging Spectrograph echelle modes) in 1%-2% of the observing time. This has led to a significant increase in the total data volume and data quality available to the community. For example, in the first 20 months of science operation (2009 September-2011 June) the cumulative redshift pathlength of extragalactic sight lines sampled by COS is nine times than sampled at moderate resolution in 19 previous years of Hubble observations. COS programs have observed 214 distinct lines of sight suitable for study of the intergalactic medium as of 2011 June. COS has measured, for the first time with high reliability, broad Ly{alpha} absorbers and Ne VIII in the intergalactic medium, and observed the He II reionization epoch along multiple sightlines. COS has detected the first CO emission and absorption in the UV spectra of low-mass circumstellar disks at the epoch of giant planet formation, and detected multiple ionization states of metals in extra-solar planetary atmospheres. In the coming years, COS will continue its census of intergalactic gas, probe galactic and cosmic structure, and explore physics in our solar system and Galaxy.

  5. The Cosmic Origins Spectrograph

    Science.gov (United States)

    Green, James C.; Froning, Cynthia S.; Osterman, Steve; Ebbets, Dennis; Heap, Sara H.; Leitherer, Claus; Linsky, Jeffrey L.; Savage, Blair D.; Sembach, Kenneth; Shull, J. Michael; Siegmund, Oswald H. W.; Snow, Theodore P.; Spencer, John; Stern, S. Alan; Stocke, John; Welsh, Barry; Beland, Stephane; Burgh, Eric B.; Danforth, Charles; France, Kevin; Keeney, Brian; McPhate, Jason; Penton, Steven V; Andrews, John; Morse, Jon

    2010-01-01

    The Cosmic Origins Spectrograph (COS) is a moderate-resolution spectrograph with unprecedented sensitivity that was installed into the Hubble Space Telescope (HST) in May 2009, during HST Servicing Mission 4 (STS-125). We present the design philosophy and summarize the key characteristics of the instrument that will be of interest to potential observers. For faint targets, with flux F(sub lambda) approximates 1.0 X 10(exp -14) ergs/s/cm2/Angstrom, COS can achieve comparable signal to noise (when compared to STIS echelle modes) in 1-2% of the observing time. This has led to a significant increase in the total data volume and data quality available to the community. For example, in the first 20 months of science operation (September 2009 - June 2011) the cumulative redshift pathlength of extragalactic sight lines sampled by COS is 9 times that sampled at moderate resolution in 19 previous years of Hubble observations. COS programs have observed 214 distinct lines of sight suitable for study of the intergalactic medium as of June 2011. COS has measured, for the first time with high reliability, broad Lya absorbers and Ne VIII in the intergalactic medium, and observed the HeII reionization epoch along multiple sightlines. COS has detected the first CO emission and absorption in the UV spectra of low-mass circumstellar disks at the epoch of giant planet formation, and detected multiple ionization states of metals in extra-solar planetary atmospheres. In the coming years, COS will continue its census of intergalactic gas, probe galactic and cosmic structure, and explore physics in our solar system and Galaxy.

  6. "Origin," "creation," and "origin of life" some conceptual considerations.

    Science.gov (United States)

    Charpa, Ulrich

    2012-01-01

    This paper opens by drawing attention to the fact that there is some conceptual confusion with regard to "origin" and "creation." This has its historical roots in the beginnings of modern science and undoubtedly affects our positioning towards the evolutionism/creationism-debate. This article argues that there are relevant ontological, epistemological, thematic, methodological, and logical differences between "origin" and "creation." As a result, the analysis suggests keeping the usage of both concepts strictly quite separate. Creation is not simply another word for origin nor does it stand for an (from a rigid scientific point of view) awkward example of an origin. Irrespective of the apparent similarities as explanatory factors, origin and creation belong to fundamentally different types of concepts. Consequently, "origin of life" and those scientific projects connected to it present themselves as something distinct that neither competes nor meshes with thinking about creation.

  7. Origins of narcissism in children

    NARCIS (Netherlands)

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

  8. 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

  9. 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)

  10. Origin products from African forests

    DEFF Research Database (Denmark)

    Egelyng, Henrik; Bosselmann, Aske Skovmand; Warui, Mary;

    2016-01-01

    Many tropical countries have potential for adding market value to unique forest origin products similarly to how EU gain billions of Euro's annually from registering agricultural origin products, with Protected Denomination of Origin or Protected Geographical Indication. Following analysis...... presents major challenges for the development of GI products and markets, exemplified by the Kenyan GI bill which is not yet enacted after almost a decade in the making....... of the renaissance for the global Geographical Indication (GI) regime, this article provides case-studies from Kenya – on Mwingi Honey, Kakamega Silk and institutional conditions under which producers may incorporate territory specific cultural, environmental, and social qualities of their unique products. We...

  11. Malignant chondroblastoma of extraskeletal origin.

    Science.gov (United States)

    Duttaluri, Ramu; Sultanpurkar, Guru Prasad; Raorane, Harshvardhan; Vikram, Harsha

    2016-01-01

    Chondroblastoma is a rare benign neoplasm of cartilaginous origin. It typically arises in the epiphysis of a long bone. They occur mostly in the second decade of life and is more common in males. Extraskeletal origin of chondroblastoma is a rarity and virulent behavior by its local aggressive nature or metastasis is reported in very few cases. We hereby, present a case of chondroblastoma in the left popliteal fossa first of its kind in a 62-year-old female, primary tumor extraskeletal in origin which turned locally aggressive and eventually metastasized to lungs. The patient is now on palliative therapy.

  12. 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.

  13. Word Origins: Building Communication Connections.

    Science.gov (United States)

    Rubenstein, Rheta N.

    2000-01-01

    Proposes examining word origins as a teaching strategy for helping middle school students speak the language of mathematics as well as promote students' general vocabulary development. Includes roots, meanings, related words, and notes for middle school mathematics vocabulary. (KHR)

  14. Word Origins: Building Communication Connections.

    Science.gov (United States)

    Rubenstein, Rheta N.

    2000-01-01

    Proposes examining word origins as a teaching strategy for helping middle school students speak the language of mathematics as well as promote students' general vocabulary development. Includes roots, meanings, related words, and notes for middle school mathematics vocabulary. (KHR)

  15. Input calibration for negative originals

    Science.gov (United States)

    Tuijn, Chris

    1995-04-01

    One of the major challenges in the prepress environment consists of controlling the electronic color reproduction process such that a perfect match of any original can be realized. Whether this goal can be reached depends on many factors such as the dynamic range of the input device (scanner, camera), the color gamut of the output device (dye sublimation printer, ink-jet printer, offset), the color management software etc. The characterization of the color behavior of the peripheral devices is therefore very important. Photographs and positive transparents reflect the original scene pretty well; for negative originals, however, there is no obvious link to either the original scene or a particular print of the negative under consideration. In this paper, we establish a method to scan negatives and to convert the scanned data to a calibrated RGB space, which is known colorimetrically. This method is based on the reconstruction of the original exposure conditions (i.e., original scene) which generated the negative. Since the characteristics of negative film are quite diverse, a special calibration is required for each combination of scanner and film type.

  16. The origins of research into the origins of life.

    Science.gov (United States)

    Fry, Iris

    2006-03-01

    Most scientists at the end of the 19th and the beginning of the 20th century chose to ignore the question of the origin of life on Earth, regarding it as too mysterious and complex to handle. Yet, in the early 1950s an experimental field devoted to the study of the problem made its first steps. The pioneering theories of several scientists in the first decades of the 20th century played a major role in this transformation, notably those of the Russian biochemist Alexander I. Oparin and the British geneticist and biochemist J.B.S. Haldane. The ideas of the lesser-known American psycho-physiologist Leonard Troland also made a significant contribution to subsequent developments in origin-of-life research. Therefore, it is well worth taking a look at the professional, philosophical and ideological commitments that shaped the approaches of the three scientists to origin-of-life research.

  17. Endosymbiotic theories for eukaryote origin

    Science.gov (United States)

    Martin, William F.; Garg, Sriram; Zimorski, Verena

    2015-01-01

    For over 100 years, endosymbiotic theories have figured in thoughts about the differences between prokaryotic and eukaryotic cells. More than 20 different versions of endosymbiotic theory have been presented in the literature to explain the origin of eukaryotes and their mitochondria. Very few of those models account for eukaryotic anaerobes. The role of energy and the energetic constraints that prokaryotic cell organization placed on evolutionary innovation in cell history has recently come to bear on endosymbiotic theory. Only cells that possessed mitochondria had the bioenergetic means to attain eukaryotic cell complexity, which is why there are no true intermediates in the prokaryote-to-eukaryote transition. Current versions of endosymbiotic theory have it that the host was an archaeon (an archaebacterium), not a eukaryote. Hence the evolutionary history and biology of archaea increasingly comes to bear on eukaryotic origins, more than ever before. Here, we have compiled a survey of endosymbiotic theories for the origin of eukaryotes and mitochondria, and for the origin of the eukaryotic nucleus, summarizing the essentials of each and contrasting some of their predictions to the observations. A new aspect of endosymbiosis in eukaryote evolution comes into focus from these considerations: the host for the origin of plastids was a facultative anaerobe. PMID:26323761

  18. Origin(s) of Antarctica's Wilkes subglacial basin

    NARCIS (Netherlands)

    Weihaupt, J.G.; Van der Hoeven, F.G.; Lorius, C.; Chambers, F.B.

    2013-01-01

    The Wilkes Subglacial Basin (WSB), the largest subglacial basin in East Antarctica, is a topographic depression of continental proportions that lies beneath the East Antarctic continental ice sheet. Discovered by the US Victoria Land Traverse 1959–60, the origin of the WSB and the influence of palae

  19. Early life origins of obesity.

    Science.gov (United States)

    Newnham, John P; Pennell, Craig E; Lye, Stephen J; Rampono, Jonathan; Challis, John R G

    2009-06-01

    There is increasing evidence that obesity has its origins in early life. Predisposition is based on interactions between the genome and environmental influences acting through epigenetic modifications. Individuals most at risk are those whose ancestral line has made a rapid transition from a traditional to a Westernized style of life. The process involves not only metabolism, but also behavior. As a result, those people who are most at risk of obesity may be those least likely to respond to educational programs based on lifestyle modification. Understanding the mechanisms and pathways that underpin the early origins of obesity is vital if we are to make progress in addressing this major problem of modern life.

  20. 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

  1. 7 CFR 201.14 - Origin.

    Science.gov (United States)

    2010-01-01

    ... hybrid seed corn) shall be labeled to show: (1) The origin, if known; or (2) if the origin is not known... as originating in such portion of a State. (c) Reasonable precautions to insure that the origin of... precautions have been taken to insure the origin to be that which is represented....

  2. 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...

  3. 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....

  4. Origin of the 'Extra Entropy'

    Science.gov (United States)

    Mushotzky, R.

    2008-01-01

    I will discuss how one can determine the origin of the 'extra entropy' in groups and clusters and the feedback needed in models of galaxy formation. I will stress the use of x-ray spectroscopy and imaging and the critical value that Con-X has in this regard.

  5. The Origin of Chinese Characters

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    IN oracle-bone inscription, 面 (mian) depictsthe outline of a face with a large eye at its center.To this end its original meaning was the humanface. However, in ancient Chinese 面 referred tothe front of the head and another characterdenoted the cheek, specifically the area between

  6. Hybrid origin of Audubon's warbler.

    Science.gov (United States)

    Brelsford, Alan; Milá, Borja; Irwin, Darren E

    2011-06-01

    Several animal species have recently been shown to have hybrid origins, but no avian examples have been documented with molecular evidence. We investigate whether the Audubon's warbler (Dendroica auduboni), one of four visually distinct species in the yellow-rumped warbler complex, has originated through hybridization between two other species in this group, the myrtle warbler (D. coronata) and black-fronted warbler (D. nigrifrons). Analysis of nuclear amplified fragment length polymorphism (AFLP) and sequence markers shows that Audubon's warblers are genetically intermediate and carry a mixture of alleles otherwise found only in one or the other of their putative parental species. Audubon's warblers also carry two deeply divergent mitochondrial DNA lineages, each shared with only one putative parental form. Broad clines between Audubon's and black-fronted warblers in AFLP markers call into question the validity of these two forms as full species; nevertheless, our results suggest that the Audubon's warbler probably originated through hybridization between two long-diverged species. It is likely that more cases of avian species of hybrid origin will be revealed by surveys of variation in nuclear DNA and other traits. © 2011 Blackwell Publishing Ltd.

  7. The Origin of Chinese Characters

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    IN ancient Chinese characters,母(pronounced mu)depicts a womanbending on her knees and crossingher hands in front with two points onher chest symbolizing her breasts.The original meaning of 母 is anadult woman who has given birth tochildren,i.e.a mother It was later

  8. [Facial pain of cardiac origin].

    Science.gov (United States)

    Peñarrocha Diago, M; Silvestre Donat, F J; Rodriguez Gil, R

    1990-01-01

    Two cases of anginal pain limited to the mandible with secondary radiation of the pain to the neck and clavicular region are presented. Although the pain was initially diagnosed as odontogenic in origin, further historial workup suggest the suspicion of referred pain from coronary insufficiency. Appropriate medical referral confirmed diagnostic suspicions. Important aspects involved with differential diagnosis of referred anginal pain are also discussed.

  9. Historical development of origins research.

    Science.gov (United States)

    Lazcano, Antonio

    2010-11-01

    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

  10. Evolutionary origins of membrane proteins

    Science.gov (United States)

    Mulkidjanian, Armen Y.; Galperin, Michael Y.

    Although the genes that encode membrane proteins make about 30% of the sequenced genomes, the evolution of membrane proteins and their origins are still poorly understood. Here we address this topic by taking a closer look at those membrane proteins the ancestors of which were present in the Last Universal Common Ancestor, and in particular, the F/V-type rotating ATPases. Reconstruction of their evolutionary history provides hints for understanding not only the origin of membrane proteins, but also of membranes themselves. We argue that the evolution of biological membranes could occur as a process of coevolution of lipid bilayers and membrane proteins, where the increase in the ion-tightness of the membrane bilayer may have been accompanied by a transition from amphiphilic, pore-forming membrane proteins to highly hydrophobic integral membrane complexes.

  11. Massive ascites of unknown origin

    Science.gov (United States)

    Yuan, Shi-Min

    2014-01-01

    Massive ascites of unknown origin is an uncommon condition, which represent a diagnostic challenge. Patients with delayed diagnosis and treatment may have a poor prognosis. A 22-year-old female was referred to this hospital due to a 4-year progressive abdominal distension with massive ascites of unknown origin. By thorough investigations, she was eventually diagnosed as chronic calcified constrictive pericarditis. She received pericardiectomy and had an uneventful postoperative course. With a few day paracentesis, ascites did not progress any more. She was doing well at 5-month follow-up and has returned to work. Extracardiac manifestations, such as massive ascites and liver cirrhosis, were rare in patients with constrictive pericarditis. Pericardiectomy can be a radical solution for the treatment of chronic constrictive pericarditis. In order to avoid delayed diagnosis and treatment, physicians have to bear in mind this rare manifestation of chronic calcified constrictive pericarditis. PMID:24600502

  12. Cosmic Ray Origins: An Introduction

    Science.gov (United States)

    Blandford, Roger; Simeon, Paul; Yuan, Yajie

    2014-11-01

    Physicists have pondered the origin of cosmic rays for over a hundred years. However the last few years have seen an upsurge in the observation, progress in the theory and a genuine increase in the importance attached to the topic due to its intimate connection to the indirect detection of evidence for dark matter. The intent of this talk is to set the stage for the meeting by reviewing some of the basic features of the entire cosmic ray spectrum from GeV to ZeV energy and some of the models that have been developed. The connection will also be made to recent developments in understanding general astrophysical particle acceleration in pulsar wind nebulae, relativistic jets and gamma ray bursts. The prospects for future discoveries, which may elucidate the origin of cosmic rays, are bright.

  13. Cosmic Ray Origins: An Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Blandford, Roger; Simeon, Paul; Yuan, Yajie

    2014-11-15

    Physicists have pondered the origin of cosmic rays for over a hundred years. However the last few years have seen an upsurge in the observation, progress in the theory and a genuine increase in the importance attached to the topic due to its intimate connection to the indirect detection of evidence for dark matter. The intent of this talk is to set the stage for the meeting by reviewing some of the basic features of the entire cosmic ray spectrum from GeV to ZeV energy and some of the models that have been developed. The connection will also be made to recent developments in understanding general astrophysical particle acceleration in pulsar wind nebulae, relativistic jets and gamma ray bursts. The prospects for future discoveries, which may elucidate the origin of cosmic rays, are bright.

  14. Cosmic Ray Origins: An Introduction

    CERN Document Server

    Blandford, Roger; Yuan, Yajie

    2014-01-01

    Physicists have pondered the origin of cosmic rays for over a hundred years. However the last few years have seen an upsurge in the observation, progress in the theory and a genuine increase in the importance attached to the topic due to its intimate connection to the indirect detection of evidence for dark matter. The intent of this talk is to set the stage for the meeting by reviewing some of the basic features of the entire cosmic ray spectrum from GeV to ZeV energy and some of the models that have been developed. The connection will also be made to recent developments in understanding general astrophysical particle acceleration in pulsar wind nebulae, relativistic jets and gamma ray bursts. The prospects for future discoveries, which may elucidate the origin of cosmic rays, are bright.

  15. Origin of the Chemical Elements

    CERN Document Server

    Rauscher, T

    2010-01-01

    This review provides the necessary background from astrophysics, nuclear, and particle physics to understand the cosmic origin of the chemical elements. It reflects the year 2009 state of the art in this extremely quickly developing interdisciplinary research direction. The discussion summarizes the nucleosynthetic processes in the course of the evolution of the Universe and the galaxies contained within, including primordial nucleosynthesis, stellar evolution, and explosive nucleosynthesis in single and binary systems.

  16. Industry Resource Meets Creative Originality

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Accompanied with the industry value chain extension,the creative originality research and promotion are becoming the major voice of textile industry.Currently,"2010 China International Fabric Design Contest & China Textile City Recommendation Meeting" convened in Beijing ceremoniously.Vice-chairman of China Textile & Apparel Council,Wang Tiankai and head of Shaoxing city government participated in the conference and gave speech on the industry market circumstance.

  17. Origin of Triton and Pluto

    Energy Technology Data Exchange (ETDEWEB)

    McKinnon, W.B. (Washington Univ., St. Louis, MO (USA). Nuclear Medicine Div.)

    1984-09-27

    A simple hypothesis on the origin of Triton and Pluto is that Triton and Pluto are independent representatives of large outer Solar System planetesimals. Triton is simply captured, with potentially spectacular consequences that include runaway melting of interior ices and release to the surface of clathrated CH/sub 4/, CO and N/sub 2/. Condensed remnants of this proto-atmosphere could account for features in Triton's unique spectrum.

  18. Swine origin influenza (swine flu).

    Science.gov (United States)

    Sebastian, Meghna R; Lodha, Rakesh; Kabra, S K

    2009-08-01

    Swine origin influenza was first recognized in the border area of Mexico and United States in April 2009 and during a short span of two months became the first pandemic. The currently circulating strain of swine origin influenza virus of the H1N1 strain has undergone triple reassortment and contains genes from the avian, swine and human viruses. It is transmitted by droplets or fomites. Incubation period is 2 to 7 days. Common clinical symptoms are indistinguishable by any viral respiratory illness, and include fever, cough, sore throat and myalgia. A feature seen more frequently with swine origin influenza is GI upset. Less than 10% of patients require hospitalization. Patients at risk of developing severe disease are - younger than five years, elderly, pregnant women, with chronic systemic illnesses, adolescents on aspirin. Of the severe manifestations of swine origin influenza, pneumonia and respiratory failure are the most common. Unusual symptoms reported are conjunctivitis, parotitis, hemophagocytic syndrome. Infants may present with fever and lethargy with no respiratory symptoms. Diagnosis is based on RT PCR, Viral culture or increasing neutralizing antibodies. Principle of treatment consist of isolation, universal precautions, good infection control practices, supportive care and use of antiviral drugs. Antiviral drugs effective against H1N1 virus include: oseltamivir and zamanavir. With good supportive care case fatality is less than 1%. Preventive measures include: social distancing, practicing respiratory etiquette, hand hygiene and use of chemoprohylaxis with antiviral drugs. Vaccine against H1N1 is not available at present, but will be available in near future.

  19. Origin of supermassive black holes

    OpenAIRE

    Dokuchaev, V. I.; Eroshenko, Yu. N.; Rubin, S G

    2007-01-01

    The origin of supermassive black holes in the galactic nuclei is quite uncertain in spite of extensive set of observational data. We review the known scenarios of galactic and cosmological formation of supermassive black holes. The common drawback of galactic scenarios is a lack of time and shortage of matter supply for building the supermassive black holes in all galaxies by means of accretion and merging. The cosmological scenarios are only fragmentarily developed but propose and pretend to...

  20. Hybrid origins of cultivated potatoes.

    Science.gov (United States)

    Rodríguez, Flor; Ghislain, Marc; Clausen, Andrea M; Jansky, Shelley H; Spooner, David M

    2010-10-01

    Solanum section Petota is taxonomically difficult, partly because of interspecific hybridization at both the diploid and polyploid levels. The taxonomy of cultivated potatoes is particularly controversial. Using DNA sequence data of the waxy gene, we here infer relationships among the four species of cultivated potatoes accepted in the latest taxonomic treatment (S. ajanhuiri, S. curtilobum, S. juzepczukii and S. tuberosum, the latter divided into the Andigenum and Chilotanum Cultivar Groups). The data support prior ideas of hybrid origins of S. ajanhuiri from the S. tuberosum Andigenum Group (2x = S. stenotomum) × S. megistacrolobum; S. juzepczukii from the S. tuberosum Andigenum Group (2x = S. stenotomum) × S. acaule; and S. curtilobum from the S. tuberosum Andigenum Group (4x = S. tuberosum subsp. andigenum) × S. juzepczukii. For the tetraploid cultivar-groups of S. tuberosum, hybrid origins are suggested entirely within much more closely related species, except for two of three examined accessions of the S. tuberosum Chilotanum Group that appear to have hybridized with the wild species S. maglia. Hybrid origins of the crop/weed species S. sucrense are more difficult to support and S. vernei is not supported as a wild species progenitor of the S. tuberosum Andigenum Group.

  1. Origins Space Telescope: Community Participation

    Science.gov (United States)

    Carey, Sean J.; Origins Space Telescope Study Team

    2017-01-01

    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. This poster will outline the ways in which the astronomical community can participate in the STDT activities and a summary of tools that are currently available or are planned for the community during the study. 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.

  2. Origin and differentiation of microglia

    Directory of Open Access Journals (Sweden)

    Florent eGinhoux

    2013-04-01

    Full Text Available Microglia are the resident macrophage population of the central nervous system (CNS. Adequate microglial function is crucial for a healthy CNS. Microglia are not only the first immune sentinels of infection, contributing to both innate and adaptive immune responses locally, but are also involved in the maintenance of brain homeostasis. Emerging data are showing new and fundamental roles for microglia in the control of neuronal proliferation and differentiation, as well as in the formation of synaptic connections. While microglia have been studied for decades, a long history of experimental misinterpretation meant that their true origins remained debated. However, recent studies on microglial origin indicate that these cells in fact arise early during development from progenitors in the embryonic yolk sac that seed the brain rudiment and, remarkably, appear to persist there into adulthood. Here, we review the history of microglial cells and discuss the latest advances in our understanding of their origin, differentiation and homeostasis, which provides new insights into their roles in health and disease.

  3. 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'.

  4. Origins Space Telescope: Study Plan

    Science.gov (United States)

    Cooray, Asantha R.; Origins Space Telescope Study Team

    2017-01-01

    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.

  5. 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.

  6. 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

  7. 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

  8. 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

  9. The Origins of Ethnolinguistic Diversity

    Science.gov (United States)

    Michalopoulos, Stelios

    2013-01-01

    This study explores the determinants of ethnolinguistic diversity within as well as across countries shedding light on its geographic origins. The empirical analysis conducted across countries, virtual countries and pairs of contiguous regions establishes that geographic variability, captured by variation in regional land quality and elevation, is a fundamental determinant of contemporary linguistic diversity. The findings are consistent with the proposed hypothesis that differences in land endowments gave rise to location-specific human capital, leading to the formation of localized ethnicities. PMID:25258434

  10. The Origins of Counting Algorithms

    OpenAIRE

    Cantlon, Jessica F.; Piantadosi, Steven T.; Ferrigno, Stephen; Hughes, Kelly D.; Allison M Barnard

    2015-01-01

    Humans’ ability to ‘count’ by verbally labeling discrete quantities is unique in animal cognition. The evolutionary origins of counting algorithms are not understood. We report that non-human primates exhibit a cognitive ability that is algorithmically and logically similar to human counting. Monkeys were given the task of choosing between two food caches. Monkeys saw one cache baited with some number of food items, one item at a time. Then, a second cache was baited with food items, one at a...

  11. Origins of the magnetomechanical effect

    Energy Technology Data Exchange (ETDEWEB)

    Bulte, D.P. E-mail: daniel.bulte@utoronto.ca; Langman, R.A. E-mail: r.langman@utas.edu.au

    2002-10-01

    A hypothesis is presented to explain the mechanism by which externally applied stresses can affect the magnetic properties of ferromagnetic materials. Experiments have revealed coincident points in the second and fourth quadrants on stressed hysteresis loops of mild steel. The results are presented along with an explanation of this effect. An atomic level theory of the origins of the magnetomechanical effect is introduced whereby spin-spin and spin-orbit coupling interact with magnetic moments to alter the magnetocrystalline anisotropy and exchange energies.

  12. [Origination and evolution of plastids].

    Science.gov (United States)

    Mukhina, V S

    2014-01-01

    Plastids are photosynthetic DNA-containing organelles of plants and algae. In the review, the history of their origination and evolution within different taxa is considered. All of the plastids appear to be descendants of cyanobacteria that colonized eukaryotic cells. The first plastids arose through symbiosis of cyanobacteria with algal ancestors from Archaeplastida kingdom. Later, there occurred repeated secondary symbioses of other eukariotes with photosynthetic protists: in this way plastids emerged in organisms of other taxa. Co-evolution of cyanobacteria and ancestral algae led to extensive transformation of both: reduction of endosymbiont, mass transfer of cyanobacteria genes into karyogenome, formation of complex system of proteins transportation to plastids and their functioning regulation.

  13. Cultural Origins of English Idioms

    Institute of Scientific and Technical Information of China (English)

    沈冬欢

    2012-01-01

      Language and culture are inseparable. Culture contains language while language carries culture (Hu,2011:146). As the essence of a language, idioms are believed to be the most culturally loaded expressions in it. Accordingly, they are often consid⁃ered as the mirror of culture, reflecting the special features of different cultures (Yu,1999:132). Hence, it is of vital importantce for English learners to trace the root of English idioms and understand their connotations culturally. This paper aims to explore the cultural origins of English idiomatic expressions from four perspectives, involving history, mythology, religion and society.

  14. Malacoplakia of probable retroperitoneal origin.

    Directory of Open Access Journals (Sweden)

    Kumon,Hiromi

    1979-12-01

    Full Text Available A case of extravesical malacoplakia, the first case in Japan, is described in detail. The patient was a 61-year-old woman with a right flank mass. Radiologically, the mass was thought to be of the renal origin. Surgically, however, the tumor was found attached not only to the cortical surface but extended to the retroperitoneum and psoas muscle. Pathological examination confirmed the lesion to be malacoplakia characterized by the presence of von Hansemann cells and Michaelis-Gutmann bodies.

  15. 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.

  16. The origins of modern divorce.

    Science.gov (United States)

    Coontz, Stephanie

    2007-03-01

    High rates of marital dissolution and easy access to divorce are not unprecedented, historically or cross-culturally. But contemporary divorce in North America and Western Europe has different origins and features than divorce in previous cultures. The origins of modern divorce patterns date back more than 200 years, to the invention of the historically unprecedented idea that marriage should be based on love and mutual affection. Ironically, then, the fragility of modern marriage stems from the same values that have elevated the marital relationship above all other personal and familial commitments: the concentration of emotion, passion, personal identity, and self-validation in the couple relationship and the attenuation of emotional attachments and obligations beyond the conjugal unit. The immediate causes of divorce may range from factors as diverse as the personal psychological characteristics of one or both spouses to the stresses of economic hardship and community disintegration. But in a larger perspective, the role of divorce in modern societies and its relatively high occurrence both flow from the same complex of factors that have made good marriages so much more central to people's happiness than through most of the past, and deterioration of a marital relationship so much more traumatic.

  17. Entropic origin of allometry relations

    Science.gov (United States)

    West, Bruce J.; West, Damien

    2015-03-01

    The theoretical allometry relation (AR) between the size of a network Y and a property of the network X is of the form X = aYb and has been known for nearly two centuries. The allometry coefficient a and allometry exponent b have been fit by various data sets over that time. The ubiquity of ARs in biology, sociology, ecology and indeed in virtually all the other science disciplines entreats science to find the origin of ARs. Data analysis indicates that the empirical AR is obtained with the replacements X → and Y → and the brackets denote an average over an ensemble of realizations of the network. It has been shown that the empirical AR cannot usually be derived from the theoretical one by simple averaging due to the fractal statistics of the fluctuations. Consequently we hypothesize that a possible origin of AR is the Principle of Minimum Entropy Generation (PMEG). We establish in support of this hypothesis that if the fluctuations in the allometry variables have fractal statistics then the PMEG entails the AR between a complex host network and a subnetwork strongly coupled to it.

  18. 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.

  19. 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).

  20. On the origin of life.

    Science.gov (United States)

    Szostak, Jack W

    2016-01-01

    The origin of life is a very rich field, filled with possibilities and ripe for discovery. RNA replication requires chemical energy and vesicle division is easy to do with mechanical energy. These requirements point to a surface lake, perhaps at some time following the period of concentrated cyanide chemistry that gave rise to nucleotides, amino acids and (maybe) fatty acids. A second requirement follows specifically from the nature of the RNA replication cycle, which requires generally cool to moderate temperatures for the copying chemistry, punctuated by brief periods of high temperature for strand separation. Remarkably, lakes in a geothermal active area provide just such a fluctuating temperature environment, because lakes similar to Yellowstone can be generally cool (even ice covered in winter), but they contain numerous hydrothermal vents that emit streams of hot water. Protocells in such an environment would occasionally be swept into these hot water streams, where the transient high temperature exposure would cause RNA strand separation. However, the protocells would be quickly mixed with surrounding cold water, and would therefore cool quickly, before their delicate RNA molecules could be destroyed by heat. Because of the combination of favorable chemical and physical environments, this could be the most likely scenario for the early Earth environment that nurtured the origin of life.

  1. 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.

    2015-01-01

    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 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. PMID:25775577

  2. 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.

  3. Strain-level diversity of secondary metabolism in the biocontrol species Aneurinibacillus migulanus.

    Science.gov (United States)

    Alenezi, Faizah N; Rekik, Imen; Bełka, Marta; Ibrahim, Abrar F; Luptakova, Lenka; Jaspars, Marcel; Woodward, Steve; Belbahri, Lassaad

    2016-01-01

    Aneurinibacillus migulanus strains Nagano and NCTC 7096 show potential in biocontrol against fungal and fungus-like plant pathogens, including a wide range of Ascomycota, Basidiomycota, and Oomycetes. Differences in terms of the range of pathogens that each strain inhibits, however, suggested that production of a single antibiotic cyclic peptide, gramicidin S (GS), by the two strains, is not the sole mechanism of inhibition. The availability of four sequenced genomes of Aneurinibacillus prompted us to apply genome mining techniques to identify the bioactive potential of A. migulanus and to provide insights into the secondary metabolite arsenal of the genus Aneurinibacillus. Up to eleven secondary metabolite biosynthetic gene clusters were present in the three Aneurinibacillus species. Biosynthetic gene clusters specifying bacteriocins, microcins, non-ribosomal peptides, polyketides, terpenes, phosphonates, lasso peptides and linaridins were identified. Chitinolytic potential and iron metabolism regulation were also investigated. With increasing numbers of biocontrol bacterial genomes being sequenced and mined, the use of approaches similar to those described in this paper will lead to an increase in the numbers of environmentally friendly natural products available to use against plant diseases. Copyright © 2015 Elsevier GmbH. All rights reserved.

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

    Science.gov (United States)

    Gensel, Sebastian; Garcia-Gonzalez, Eva; Ebeling, Julia; Skobalj, Ranko; Kuthning, Anja; Süssmuth, Roderich D.

    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. PMID:27760211

  5. Early settlers: which E. coli strains do you not want at birth?

    Science.gov (United States)

    Secher, Thomas; Brehin, Camille; Oswald, Eric

    2016-07-01

    The intestinal microbiota exerts vital biological processes throughout the human lifetime, and imbalances in its composition have been implicated in both health and disease status. Upon birth, the neonatal gut moves from a barely sterile to a massively colonized environment. The development of the intestinal microbiota during the first year of life is characterized by rapid and important changes in microbial composition, diversity, and magnitude. The pioneer bacteria colonizing the postnatal intestinal tract profoundly contribute to the establishment of the host-microbe symbiosis, which is essential for health throughout life. Escherichia coli is one of the first colonizers of the gut after birth. E. coli is a versatile population including harmless commensal, probiotic strains as well as frequently deadly pathogens. The prevalence of the specific phylogenetic B2 group, which encompasses both commensal and extra- or intraintestinal pathogenic E. coli strains, is increasing among E. coli strains colonizing infants quickly after birth. Fifty percent of the B2 group strains carry in their genome the pks gene cluster encoding the synthesis of a nonribosomal peptide-polyketide hybrid genotoxin named colibactin. In this review, we summarize both clinical and experimental evidence associating the recently emerging neonatal B2 E. coli population with several pathology and discuss how the expression of colibactin by both normal inhabitants of intestinal microflora and virulent strains may darken the borderline between commensalism and pathogenicity. Copyright © 2016 the American Physiological Society.

  6. The colibactin warhead crosslinks DNA

    Science.gov (United States)

    Vizcaino, Maria I.; Crawford, Jason M.

    2015-05-01

    Members of the human microbiota are increasingly being correlated to human health and disease states, but the majority of the underlying microbial metabolites that regulate host-microbe interactions remain largely unexplored. Select strains of Escherichia coli present in the human colon have been linked to the initiation of inflammation-induced colorectal cancer through an unknown small-molecule-mediated process. The responsible non-ribosomal peptide-polyketide hybrid pathway encodes ‘colibactin’, which belongs to a largely uncharacterized family of small molecules. Genotoxic small molecules from this pathway that are capable of initiating cancer formation have remained elusive due to their high instability. Guided by metabolomic analyses, here we employ a combination of NMR spectroscopy and bioinformatics-guided isotopic labelling studies to characterize the colibactin warhead, an unprecedented substituted spirobicyclic structure. The warhead crosslinks duplex DNA in vitro, providing direct experimental evidence for colibactin's DNA-damaging activity. The data support unexpected models for both colibactin biosynthesis and its mode of action.

  7. Increased production of yersiniabactin and an anthranilate analog through media optimization.

    Science.gov (United States)

    Moscatello, Nicholas; Qi, Ruiquan; Ahmadi, Mahmoud Kamal; Pfeifer, Blaine A

    2017-05-25

    Yersiniabactin (Ybt) is a mixed nonribosomal peptide-polyketide natural product that binds a wide range of metals with the potential to impact processes requiring metal retrieval and removal. In this work, we substantially improved upon the heterologous production of Ybt and an associated anthranilate analog through systematic screening and optimization of culture medium components. Specifically, a Plackett-Burman design-of-experiments methodology was used to screen 22 components and to determine those contributing most to siderophore production. L-cysteine, L-serine, glucose, and casamino acids significantly contributed to the production of both compounds. Using this approach together with metabolic engineering of the base biosynthetic process, Ybt and the anthranilate analog titers were increased to 867 ± 121 mg/L and 16.6 ± 0.3 mg/L, respectively, an increase of ∼38 and ∼79-fold relative to production in M9 medium. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 2017. © 2017 American Institute of Chemical Engineers.

  8. Geochemical Origin of Biological Molecules

    Science.gov (United States)

    Bassez, Marie-Paule

    2013-04-01

    A model for the geochemical origin of biological molecules is presented. Rocks such as peridotites and basalts, which contain ferromagnesian minerals, evolve in the presence of water. Their hydrolysis is an exothermic reaction which generates heat and a release of H2 and of minerals with modified structures. The hydrogen reacts with the CO2 embedded inside the rock or with the CO2 of the environment to form CO in an hydrothermal process. With the N2 of the environment, and with an activation source arising from cosmic radiation, ferromagnesian rocks might evolve towards the abiotic formation of biological molecules, such as peptide like macromolecules which produce amino acids after acid hydrolysis. The reactions concerned are described. The production of hydrothermal CO is discussed in geological sites containing ferromagnesian silicate minerals and the low intensity of the Earth's magnetic field during Paleoarchaean Era is also discussed. It is concluded that excitation sources arising from cosmic radiation were much more abundant during Paleoarchaean Era and that macromolecular structures of biological relevance might consequently form during Archaean Eon, as a product of the chemical evolution of the rocks and of their mineral contents. This synthesis of abiotically formed biological molecules is consecutively discussed for meteorites and other planets such as Mars. This model for the geochemical origin of biological molecules has first been proposed in 2008 in the context of reactions involving catalysers such as kaolinite [Bassez 2008a] and then presented in conferences and articles [Bassez 2008b, 2009, 2012; Bassez et al. 2009a to 2012b]. BASSEZ M.P. 2008a Synthèse prébiotique dans les conditions hydrothermales, CNRIUT'08, Lyon 29-30/05/2008, Conf. and open access article:http://liris.cnrs.fr/~cnriut08/actes/ 29 mai 11h-12h40. BASSEZ M.P. 2008b Prebiotic synthesis under hydrothermal conditions, ISSOL'08, P2-6, Firenze-Italy, 24-29/08/2008. Poster at the

  9. Origins and Evolution of Life

    Science.gov (United States)

    Gargaud, Muriel; López-García, Purificación; Martin, Hervé

    2011-01-01

    Part I. What Is Life?: 1. Problems raised by a definition of life M. Morange; 2. Some remarks about uses of cosmological anthropic 'principles' D. Lambert; 3. Minimal cell: the biologist point of view C. Brochier-Armanet; 4. Minimal cell: the computer scientist point of view H. Bersini; 5. Origins of life: computing and simulation approaches B. Billoud; Part II. Astronomical and Geophysical Context of the Emergence of Life: 6. Organic molecules in interstellar medium C. Ceccarelli and C. Cernicharo; 7. Cosmochemical evolution and the origin of life: insights from meteorites S. Pizzarello; 8. Astronomical constraints on the emergence of life M. Gounelle and T. Montmerle; 9. Formation of habitable planets J. Chambers; 10. The concept of galactic habitable zone N. Prantzos; 11. The young Sun and its influence on planetary atmospheres M. Güdel and J. Kasting; 12. Climates of the Earth G. Ramstein; Part III. Role of Water in the Emergence of Life: 13. Liquid water: a necessary condition to all forms of life K. Bartik, G. Bruylants, E. Locci and J. Reisse; 14. The role of water in the formation and evolution of planets T. Encrenaz; 15. Water on Mars J. P. Bibring; Part IV. From Non-Living Systems to Life: 16. Energetic constraints on prebiotic pathways: application to the emergence of translation R. Pascal and L. Boiteau; 17. Comparative genomics and early cell evolution A. Lazcano; 18. Origin and evolution of metabolisms J. Peretó; Part V. Mechanisms for Life Evolution: 19. Molecular phylogeny: inferring the patterns of evolution E. Douzery; 20. Horizontal gene transfer: mechanisms and evolutionary consequences D. Moreira; 21. The role of symbiosis in eukaryotic evolution A. Latorre, A. Durbán, A. Moya and J. Peretó; Part VI. Life in Extreme Conditions: 22. Life in extreme conditions: Deinococcus radiodurans, an organism able to survive prolonged desiccation and high doses of ionising radiation S. Sommer and M. Toueille; 23. Molecular effects of UV and ionizing

  10. 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.

  11. Origins of life systems chemistry

    Science.gov (United States)

    Sutherland, J.

    2015-10-01

    By reconciling previously conflicting views about the origin of life - in which one or other cellular subsystem emerges first, and then 'invents' the others - a new modus operandi for its study is suggested. Guided by this, a cyanosulfidic protometabolism is uncovered which uses UV light and the stoichiometric reducing power of hydrogen sulfide to convert hydrogen cyanide, and a couple of other prebiotic feedstock molecules which can be derived therefrom, into nucleic acid, peptide and lipid building blocks. Copper plays several key roles in this chemistry, thus, for example, copper(I) catalysed cross coupling and copper(II) driven oxidative crosscoupling reactions generate key feedstock molecules. Geochemical scenarios consistent with this protometabolism are outlined. Finally, the transition of a system from the inanimate to the animate state is considered in the context of there being intermediate stages of partial 'aliveness'.

  12. On the origin of differentiation

    Indian Academy of Sciences (India)

    J T Bonner

    2003-06-01

    Following the origin of multicellularity in many groups of primitive organisms there evolved more than one cell type. It has been assumed that this early differentiation is related to size – the larger the organism the more cell types. Here two very different kinds of organisms are considered: the volvocine algae that become multicellular by growth, and the cellular slime moulds that become multicellular by aggregation. In both cases there are species that have only one cell type and others that have two. It has been possible to show that there is a perfect correlation with size: the forms with two cell types are significantly larger than those with one. Also in both groups there are forms of intermediate size that will vary from one to two cell types depending on the size of the individuals, suggesting a form of quorum sensing. These observations reinforce the view that size plays a critical role in influencing the degree of differentiation.

  13. The origin of cortical neurons

    Directory of Open Access Journals (Sweden)

    J.G. Parnavelas

    2002-12-01

    Full Text Available Neurons of the mammalian cerebral cortex comprise two broad classes: pyramidal neurons, which project to distant targets, and the inhibitory nonpyramidal cells, the cortical interneurons. Pyramidal neurons are generated in the germinal ventricular zone, which lines the lateral ventricles, and migrate along the processes of radial glial cells to their positions in the developing cortex in an `inside-out' sequence. The GABA-containing nonpyramidal cells originate for the most part in the ganglionic eminence, the primordium of the basal ganglia in the ventral telencephalon. These cells follow tangential migratory routes to enter the cortex and are in close association with the corticofugal axonal system. Once they enter the cortex, they move towards the ventricular zone, possibly to obtain positional information, before they migrate radially in the direction of the pial surface to take up their positions in the developing cortex. The mechanisms that guide interneurons throughout these long and complex migratory routes are currently under investigation.

  14. The origin of Lotus corniculatus.

    Science.gov (United States)

    Ross, M D; Jones, W T

    1985-12-01

    Earlier students of the origin of Lotus corniculatus suggested that this tetraploid species arose as an autotetraploid of the closely related diploid species L. tenuis or L. alpinus. More recent studies suggested that L. alpinus and L. japonicus could be ancestral forms. The present study of tannin content, phenolic content, cyanide production, morphology, cytogenetics, Rhizobium specificity and self-incompatibility in the corniculatus group virtually excludes the possibility that L. corniculatus could have arisen through autopolyploidy of L. tenuis or L. alpinus, and suggests that L. corniculatus arose through hybridization of L. alpinus and/or L. tenuis (probably as female parent) with L. uliginosus (probably as male parent), followed by chromosome doubling in the hybrid.

  15. The origin of cellular life

    Science.gov (United States)

    Ingber, D. E.

    2000-01-01

    This essay presents a scenario of the origin of life that is based on analysis of biological architecture and mechanical design at the microstructural level. My thesis is that the same architectural and energetic constraints that shape cells today also guided the evolution of the first cells and that the molecular scaffolds that support solid-phase biochemistry in modern cells represent living microfossils of past life forms. This concept emerged from the discovery that cells mechanically stabilize themselves using tensegrity architecture and that these same building rules guide hierarchical self-assembly at all size scales (Sci. Amer 278:48-57;1998). When combined with other fundamental design principles (e.g., energy minimization, topological constraints, structural hierarchies, autocatalytic sets, solid-state biochemistry), tensegrity provides a physical basis to explain how atomic and molecular elements progressively self-assembled to create hierarchical structures with increasingly complex functions, including living cells that can self-reproduce.

  16. Multiple origins of asteroid pairs

    CERN Document Server

    Jacobson, Seth A

    2015-01-01

    Rotationally fissioned asteroids produce unbound daughter asteroids that have very similar heliocentric orbits. Backward integration of their current heliocentric orbits provides an age of closest proximity that can be used to date the rotational fission event. Most asteroid pairs follow a predicted theoretical relationship between the primary spin period and the mass ratio of the two pair members that is a direct consequence of the YORP-induced rotational fission hypothesis. If the progenitor asteroid has strength, asteroid pairs may have high mass ratios with possibly fast rotating primaries. However, secondary fission leaves the originally predicted trend unaltered. We also describe the characteristics of pair members produced by four alternative routes from a rotational fission event to an asteroid pair. Unlike direct formation from the event itself, the age of closest proximity of these pairs cannot generally be used to date the rotational fission event since considerable time may have passed.

  17. Photorespiration: players, partners and origin.

    Science.gov (United States)

    Bauwe, Hermann; Hagemann, Martin; Fernie, Alisdair R

    2010-06-01

    Photorespiratory metabolism allows plants to thrive in a high-oxygen containing environment. This metabolic pathway recycles phosphoglycolate, a toxic compound, back to phosphoglycerate, when oxygen substitutes for carbon dioxide in the first reaction of photosynthetic carbon fixation. The recovery of phosphoglycerate is accompanied by considerable carbon and energy losses, making photorespiration a prime target for crop improvement. The genomics era has allowed the precise functional analysis of individual reaction steps of the photorespiratory cycle, and more links integrating photorespiration with cellular metabolism as a whole are becoming apparent. Here we review the evolutionary origins of photorespiration as well as new insights into the interaction with other metabolic processes such as nitrogen assimilation and mitochondrial respiration.

  18. Impact origin of the Moon

    Energy Technology Data Exchange (ETDEWEB)

    Slattery, W.L.

    1998-12-31

    A few years after the Apollo flights to the Moon, it became clear that all of the existing theories on the origin of the Moon would not satisfy the growing body of constraints which appeared with the data gathered by the Apollo flights. About the same time, researchers began to realize that the inner (terrestrial) planets were not born quietly -- all had evidences of impacts on their surfaces. This fact reinforced the idea that the planets had formed by the accumulation of planetesimals. Since the Earth`s moon is unique among the terrestrial planets, a few researchers realized that perhaps the Moon originated in a singular event; an event that was quite probable, but not so probable that one would expect all the terrestrial planets to have a large moon. And thus was born the idea that a giant impact formed the Moon. Impacts would be common in the early solar system; perhaps a really large impact of two almost fully formed planets of disparate sizes would lead to material orbiting the proto-earth, a proto-moon. This idea remained to be tested. Using a relatively new, but robust, method of doing the hydrodynamics of the collision (Smoothed-Particle Hydrodynamics), the author and his colleagues (W. Benz, Univ. of Arizona, and A.G.W. Cameron, Harvard College Obs.) did a large number of collision simulations on a supercomputer. The author found two major scenarios which would result in the formation of the Moon. The first was direct formation; a moon-sized object is boosted into orbit by gravitational torques. The second is when the orbiting material forms a disk, which, with subsequent evolution can form the Moon. In either case the physical and chemical properties of the newly formed Moon would very neatly satisfy the physical and chemical constraints of the current Moon. Also, in both scenarios the surface of the Earth would be quite hot after the collision. This aspect remains to be explored.

  19. 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.

  20. Intranodal palisaded myofibroblastoma originating from retroperitoneum: an unusual origin

    Directory of Open Access Journals (Sweden)

    Manikkapurath Hemachandran

    2011-06-01

    Full Text Available Abstract Background Intranodal palisaded myofibroblastoma is one of the primary mesenchymal tumours. The inguinal region is the commonest site of this rare tumour. As there are only about 55 such cases reported in the literature, the precise aetiology and pathogenesis have yet to be explained adequately. Here we report a case of a 72 year old man presented with incidental finding of intranodal palisaded myofibroblastoma in the retroperitoneal region. Case Presentation A 72-year old man presented with abdominal pain in right upper quadrant with an incidental finding of abdominal mass in the right flank. The computerised tomogram scan of abdomen confirmed acute cholecystitis with a 5 x 5 cm retroperitoneal mass. He underwent cholecystectomy with excision of this mass. He recovered well following his operation and was discharged from the hospital. Histological examination confirmed the diagnosis of intranodal palisaded myofibroblastoma. Conclusion To our knowledge, this is the first case of intranodal palisaded myofibroblastoma originating from retroperitoneum. Along with the rarity of this case, we also discussed its typical histopathological findings, aetiology and pathogenesis.

  1. 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)

  2. Prevolutionary dynamics and the origin of evolution

    OpenAIRE

    Nowak, Martin A.; Ohtsuki, Hisashi

    2008-01-01

    Life is that which replicates and evolves. The origin of life is also the origin of evolution. A fundamental question is when do chemical kinetics become evolutionary dynamics? Here, we formulate a general mathematical theory for the origin of evolution. All known life on earth is based on biological polymers, which act as information carriers and catalysts. Therefore, any theory for the origin of life must address the emergence of such a system. We describe prelife as an alphabet of active m...

  3. Reassessing the origin of Triton

    Science.gov (United States)

    Nogueira, E.; Brasser, R.; Gomes, R.

    2011-07-01

    The origin of Neptune's large, circular but retrograde satellite Triton has remained largely unexplained. There is an apparent consensus that its origin lies in it being captured, but until recently no successful capture mechanism has been found. Agnor and Hamilton (Agnor, C.B., Hamilton, D.P. [2006]. Nature 441, 192-194) demonstrated that the disruption of a trans-neptunian binary object which had Triton as a member, and which underwent a very close encounter with Neptune, was an effective mechanism to capture Triton while its former partner continued on a hyperbolic orbit. The subsequent evolution of Triton's post-capture orbit to its current one could have proceeded through gravitational tides (Correia, A.C.M. [2009]. Astrophys. J. 704, L1-L4), during which time Triton was most likely semi-molten (McKinnon, W.B. [1984]. Nature 311, 355-358). However, to date, no study has been performed that considered both the capture and the subsequent tidal evolution. Thus it is attempted here with the use of numerical simulations. The study by Agnor and Hamilton (Agnor, C.B., Hamilton, D.P. [2006]. Nature 441, 192-194) is repeated in the framework of the Nice model (Tsiganis, K., Gomes, R., Morbidelli, A., Levison, H.F. [2005]. Nature 435, 459-461) to determine the post-capture orbit of Triton. After capture Triton is then subjected to tidal evolution using the model of Mignard (Mignard, F. [1979]. Moon Planets 20, 301-315; Mignard, F. [1980]. Moon Planets 23, 185-201). The perturbations from the Sun and the figure of Neptune are included. The perturbations from the Sun acting on Triton just after its capture cause it to spend a long time in its high-eccentricity phase, usually of the order of 10 Myr, while the typical time to circularise to its current orbit is some 200 Myr, consistent with earlier studies. The current orbit of Triton is consistent with an origin through binary capture and tidal evolution, even though the model prefers Triton to be closer to Neptune than it

  4. 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....

  5. The Origins of Competency-Based Training

    Science.gov (United States)

    Hodge, Steven

    2007-01-01

    This article attempts to trace the origins of competency-based training (CBT), the theory of vocational education that underpins the National Training Framework in Australia. A distinction is made between societal and theoretical origins. This paper argues that CBT has its societal origins in the United States of America during the 1950s, 60s and…

  6. 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

  7. 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.

  8. Origin and development of muscle cramps.

    Science.gov (United States)

    Minetto, Marco Alessandro; Holobar, Aleš; Botter, Alberto; Farina, Dario

    2013-01-01

    Cramps are sudden, involuntary, painful muscle contractions. Their pathophysiology remains poorly understood. One hypothesis is that cramps result from changes in motor neuron excitability (central origin). Another hypothesis is that they result from spontaneous discharges of the motor nerves (peripheral origin). The central origin hypothesis has been supported by recent experimental findings, whose implications for understanding cramp contractions are discussed.

  9. Ambient neutrons of natural origin

    Science.gov (United States)

    Gusev, Anatoly; Martin, Inacio; Shkevov, Rumen; Alves, Mauro

    2016-07-01

    The laboratory of environmental radiation of ITA (São José dos Campos, 23°11'11″S, 45°52'43″W, 650 MAMSL) performs simultaneous monitoring of a natural radiation background and meteorological parameters. Neutron flux in the energy range of 0.02 eV - 10 MeV is registered with two sets of proportional ^{3}He tubes placed into cylindrical paraffin thermalizers: an {bf outdoor detector }of 250 cm² area and {bf indoor detector }of 70 cm² area located on the second floor of a concrete building. The counter efficiency for thermal neutrons is 80%. The characteristics of the observed flux variation are quite different from those inherent to the neutrons of the cosmic ray origin. {bf Four types of the outdoor flux variations }are observed: 1) {bf seasonal }with a maxima in wet seasons; 2) {bf diurnal }with maximum at about 6 h local time and an amplitude up to several dozens; 3) {bf abrupt transient} ( 1 min) increases with magnitudes up to two orders higher than the mean daily flux; 4) short (several days) {bf quasi-periodic enhancements }with amplitudes up to several times higher than the mean daily flux. A large variation of the outdoor flux and its phase synchronism with that of the radon decay products means with a high probability their common origin. An apparent source of the neutrons observed is nuclear reactions of decay α-particles with the ground matter. In this case the dynamics of the outdoor flux variations of the first two types is controlled by those of the meteorological parameters in the locality. The third type events correlate with lightning strokes in the vicinity (<200 m) of the detector. The more rare fourth type correlate neither with geomagnetic disturbances nor with meteorological phenomena and are probably a result of natural radon release from the Earth's crust triggered by minor seismological activity. The indoor flux is quite stable with a possible weak maximum at16 h not exceeding 0.1.

  10. Origin of Cosmic Chemical Abundances

    CERN Document Server

    Maio, Umberto

    2015-01-01

    Cosmological N-body hydrodynamic computations following atomic and molecular chemistry (e$^-$, H, H$^+$, H$^-$, He, He$^+$, He$^{++}$, D, D$^+$, H$_2$, H$_2^+$, HD, HeH$^+$), gas cooling, star formation and production of heavy elements (C, N, O, Ne, Mg, Si, S, Ca, Fe, etc.) from stars covering a range of mass and metallicity are used to explore the origin of several chemical abundance patterns and to study both the metal and molecular content during simulated galaxy assembly. The resulting trends show a remarkable similarity to up-to-date observations of the most metal-poor damped Lyman-$\\alpha$ absorbers at redshift $z\\gtrsim 2$. These exhibit a transient nature and represent collapsing gaseous structures captured while cooling is becoming effective in lowering the temperature below $\\sim 10^4\\,\\rm K$, before they are disrupted by episodes of star formation or tidal effects. Our theoretical results agree with the available data for typical elemental ratios, such as [C/O], [Si/Fe], [O/Fe], [Si/O], [Fe/H], [O/...

  11. The origins of counting algorithms.

    Science.gov (United States)

    Cantlon, Jessica F; Piantadosi, Steven T; Ferrigno, Stephen; Hughes, Kelly D; Barnard, Allison M

    2015-06-01

    Humans' ability to count by verbally labeling discrete quantities is unique in animal cognition. The evolutionary origins of counting algorithms are not understood. We report that nonhuman primates exhibit a cognitive ability that is algorithmically and logically similar to human counting. Monkeys were given the task of choosing between two food caches. First, they saw one cache baited with some number of food items, one item at a time. Then, a second cache was baited with food items, one at a time. At the point when the second set was approximately equal to the first set, the monkeys spontaneously moved to choose the second set even before that cache was completely baited. Using a novel Bayesian analysis, we show that the monkeys used an approximate counting algorithm for comparing quantities in sequence that is incremental, iterative, and condition controlled. This proto-counting algorithm is structurally similar to formal counting in humans and thus may have been an important evolutionary precursor to human counting. © The Author(s) 2015.

  12. The origins of cellular life.

    Science.gov (United States)

    Schrum, Jason P; Zhu, Ting F; Szostak, Jack W

    2010-09-01

    Understanding the origin of cellular life on Earth requires the discovery of plausible pathways for the transition from complex prebiotic chemistry to simple biology, defined as the emergence of chemical assemblies capable of Darwinian evolution. We have proposed that a simple primitive cell, or protocell, would consist of two key components: a protocell membrane that defines a spatially localized compartment, and an informational polymer that allows for the replication and inheritance of functional information. Recent studies of vesicles composed of fatty-acid membranes have shed considerable light on pathways for protocell growth and division, as well as means by which protocells could take up nutrients from their environment. Additional work with genetic polymers has provided insight into the potential for chemical genome replication and compatibility with membrane encapsulation. The integration of a dynamic fatty-acid compartment with robust, generalized genetic polymer replication would yield a laboratory model of a protocell with the potential for classical Darwinian biological evolution, and may help to evaluate potential pathways for the emergence of life on the early Earth. Here we discuss efforts to devise such an integrated protocell model.

  13. 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.

  14. 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.

  15. The origin of physical laws

    CERN Document Server

    Chung Ding Yu

    2002-01-01

    In the vacuum universe model, the origin of physical laws comes from the cosmic evolution of vacuum in four stages: the pre-universe vacuum, the void space, the adjacent vacuum, and the empty space. The pre-universe is a vacuum with the vacuum energy slightly below the Planck energy. The vacuum fluctuation of the pre-universe vacuum results in pairs of supermembrane and anti-supermembrane and the void space. The supermembrane pairs and the void space are self-organized into the semi-stable pre-expanding universe consisting of the positive and the negative energy boundary 9-branes separated by the bulk space with the positive energy pre-gravity and the negative energy pre-gravity. The collapse and the bounce of the pre-expanding universe result in the mixed pre-expanding universe consisting of the boundary mixed 9-branes with the absorbed void space. When the absorbed void space is emitted, it becomes the adjacent vacuum as the added space, which brings about the expansion with zero vacuum energy. The rupture ...

  16. 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

  17. The origin of intermediary metabolism

    Science.gov (United States)

    Morowitz, H. J.; Kostelnik, J. D.; Yang, J.; Cody, G. D.

    2000-01-01

    The core of intermediary metabolism in autotrophs is the citric acid cycle. In a certain group of chemoautotrophs, the reductive citric acid cycle is an engine of synthesis, taking in CO(2) and synthesizing the molecules of the cycle. We have examined the chemistry of a model system of C, H, and O that starts with carbon dioxide and reductants and uses redox couples as the energy source. To inquire into the reaction networks that might emerge, we start with the largest available database of organic molecules, Beilstein on-line, and prune by a set of physical and chemical constraints applicable to the model system. From the 3.5 million entries in Beilstein we emerge with 153 molecules that contain all 11 members of the reductive citric acid cycle. A small number of selection rules generates a very constrained subset, suggesting that this is the type of reaction model that will prove useful in the study of biogenesis. The model indicates that the metabolism shown in the universal chart of pathways may be central to the origin of life, is emergent from organic chemistry, and may be unique.

  18. Fever of unknown origin: a clinical approach.

    Science.gov (United States)

    Cunha, Burke A; Lortholary, Olivier; Cunha, Cheston B

    2015-10-01

    Fevers of unknown origin remain one of the most difficult diagnostic challenges in medicine. Because fever of unknown origin may be caused by over 200 malignant/neoplastic, infectious, rheumatic/inflammatory, and miscellaneous disorders, clinicians often order non-clue-based imaging and specific testing early in the fever of unknown origin work-up, which may be inefficient/misleading. Unlike most other fever-of-unknown-origin reviews, this article presents a clinical approach. Characteristic history and physical examination findings together with key nonspecific test abnormalities are the basis for a focused clue-directed fever of unknown origin work-up. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Cosmic Origin and Theology of the Revelation

    Science.gov (United States)

    Guijarro, José Francisco

    2007-04-01

    All along cultural history man has asked himself about the origin of man, the origin of life ante the origin of the cosmos. Regarding the question about the origin of the cosmos, any theological research must settle before any other goal the question of its language: what we understand as scientific, mythical or theological language. The biblical texts on Creation are analyzed in their historical, cultural and theological context. It is concluded that the fundamental religious meanings of the biblical texts are not in opposition to scientific interpretation of cosmic origin.

  20. 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

  1. [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

  2. On the origin of Laurentia

    Energy Technology Data Exchange (ETDEWEB)

    Dalziel, I.W.D. (Univ. of Texas, Austin, TX (United States). Inst. for Geophysics)

    1992-01-01

    Laurentia, the Precambrian core of the North American continent, is surrounded by late Precambrian rift systems and therefore constitutes a suspect terrane''. A geometric and geological fit can be achieved between the Atlantic margin of Laurentia and the Pacific margin of the Gondwana craton. The enigmatic Arequipa massif along the southern Peruvian coast, that yields ca. 2.0 Ga radiometric ages, is juxtaposed with the Makkovik-Ketilidian province of the same age range in Labrador and southern Greenland. The Greenville belt continues beneath the ensialic Andes of the present day to join up with the 1.3--1.0 Ga San Ignacio and Sonsas-Aguapei orogens of the Transamazonian craton. Together with the recent identification of possible continuations of the Greenville orogen in East Antarctica and of the Taconic Appalachians in southern South America, the fit supports suggestions that Laurentia originated between East Antarctica-Australia and embryonic South America prior to the opening of the Pacific Ocean basin and amalgamation of the Gondwana Cordilleran and Appalachian margins, this implies that there may have been two supercontinents during the Neoproterozoic, before and after opening of the Pacific Ocean. As Laurentia and Gondwana appear to have collided on at least two occasions during the Paleozoic, this scenario therefore calls to question the existence of so-called supercontinental cycles. The Arica bight of the present day may reflect a primary reentrant in the South American continental margin that controlled subduction processes along the Andean margin and eventually led to uplift of the Altiplano.

  3. On the origin of EDSS.

    Science.gov (United States)

    Kurtzke, John F

    2015-03-01

    The origin of EDSS, the Expanded Disability Status Scale for multiple sclerosis, was some 30 years before its only publication in 1983 when we were trying to assess a potential treatment and found no published methods. Findings from the complete neurologic examinations in over 200 patients were consolidated into mutually exclusive but all-inclusive neurophysiologic entities called Functional Systems (FS), and these provided the basis for an 11 step 0-10 rank order scale, the Disability Status Scale (DSS). This was used successfully, as well as in the first two Class I treatment trials performed, with the second one also incorporating the 8 FS. Both measures were part of an assessment of a natural history series derived from men hospitalized for MS in the US Army in World War II and followed for some 20 years. Describing each of the 8 FS as affected (1) or normal (0) defined 256 possible patterns of involvement for all patients. Half the patients at diagnosis had one of the 14 most common patterns. Each FS worsened in frequency and severity of involvement in correlation with the DSS, which overall showed a unimodal distribution, until in another series of patients 16 years post onset bimodality first appeared. Observations that the 11 step DSS might have too few steps for treatment trials led to the EDSS of 20 steps with each grade between 1 and 9 divided into two. The system of EDSS+FS to summarize all the CNS involvement as defined by objective findings on neurologic examination thereafter remained unchanged to the present. I just learned that the unpublished system copyrighted in Switzerland as "neurostatus" has been called and referenced as my EDSS. It is not. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Fascia Origin of Adipose Cells.

    Science.gov (United States)

    Su, Xueying; Lyu, Ying; Wang, Weiyi; Zhang, Yanfei; Li, Danhua; Wei, Suning; Du, Congkuo; Geng, Bin; Sztalryd, Carole; Xu, Guoheng

    2016-05-01

    Adipocytes might arise from vascular stromal cells, pericytes and endothelia within adipose tissue or from bone marrow cells resident in nonadipose tissue. Here, we identified adipose precursor cells resident in fascia, an uninterrupted sheet of connective tissue that extends throughout the body. The cells and fragments of superficial fascia from the rat hindlimb were highly capable of spontaneous and induced adipogenic differentiation but not myogenic and osteogenic differentiation. Fascial preadipocytes expressed multiple markers of adipogenic progenitors, similar to subcutaneous adipose-derived stromal cells (ASCs) but discriminative from visceral ASCs. Such preadipocytes resided in fascial vasculature and were physiologically active in vivo. In growing rats, adipocytes dynamically arose from the adventitia to form a thin adipose layer in the fascia. Later, some adipocytes appeared to overlay on top of other adipocytes, an early sign for the formation of three-dimensional adipose tissue in fascia. The primitive adipose lobules extended invariably along blood vessels toward the distal fascia areas. At the lobule front, nascent capillaries wrapped and passed ahead of mature adipocytes to form the distal neovasculature niche, which might replenish the pool of preadipocytes and supply nutrients and hormones necessary for continuous adipogenesis. Our findings suggest a novel model for the origin of adipocytes from the fascia, which explains both neogenesis and expansion of adipose tissue. Fascial preadipocytes generate adipose cells to form primitive adipose lobules in superficial fascia, a subcutaneous nonadipose tissue. With continuous adipogenesis, these primitive adipose lobules newly formed in superficial fascia may be the rudiment of subcutaneous adipose tissue. Stem Cells 2016;34:1407-1419.

  5. 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.

  6. Taxonomy and origin of reindeer

    Directory of Open Access Journals (Sweden)

    Knut H. Røed

    2007-04-01

    Full Text Available Reindeer and caribou was probably the key species for the human immigration and colonization in the Arctic and sub-Arctic by the retreat of the ice in the last glacial period. The close connection between human and reindeer has contributed to great interest and variation in reindeer taxonomy and origin. Through the history several both species, subspecies and types of reindeer and caribou have been described. The early taxonomy of the species is marked by comparisons of individual specimen using traits as body size, skin colour or antler formations - characteristics known to be highly variable and subjected to environmental and nutritional level. During the mid 1900s the taxonomy was more based on variation of morphological traits among populations by analysing a large series of specimens representative of the various geographic populations and a consensus of classification of several subspecies, all belonging to the same species, evolved. During late 1900 the development of modern molecular techniques procured tools for revealing genetic structure of populations reflecting different origin and isolation rather than environmental influences. The genetic structure revealed a major genetic dichotomy between American woodland caribou on the one hand and all other types of reindeer and caribou on the other which gave evidence that the ancestors of present woodland caribou had survived and evolved in ice free refugium south to the glacier in North America and the ancestors of all other types of reindeer and caribou had evolved separated from these in refugium in Eurasia and Beringia. The ancestors of present reindeer in Scandinavia appear furthermore to have evolved from different populations separated during the last glaciation period and the colonization and origin of present wild and domestic reindeer will be discussed in this perspective.Taksonomi og opprinnelse til reinAbstract in Norwegian / Sammendrag: Rein og caribou har hatt stor betydning

  7. The Origin of River Meanders

    Science.gov (United States)

    Sahagian, D. L.; Chatanantavet, P.; Bradley, C.; Friedgen-Veitch, D.; Diplas, P.

    2015-12-01

    Various propositions for the origin of meanders have been suggested in the past, involving local disturbances such as variable bank material, obstructions to flow, and sediment transport. Each of these approaches has required a very special and complex set of circumstances for the onset of meandering. However, meanders have also been observed in other systems such as the gulf stream , window glass , glacial meltwater, channels in submarine fans, the jet stream, water faucets, and many others. What has not been satisfactorily demonstrated is why some rivers (or parts of rivers) should tend to meander in the first place rather than ply a straight course to base level. We suggest that the fundamental cause of the river meander instability is simply a minimization of power (rate of work done), with an onset that occurs when inertial terms exceed body forces (e.g. gravity) acting on the flow, and thus create an adverse pressure gradient directed in the opposite direction of the flow. A simple way to visualize the cause of the instability is that the water "backs up" upon itself, running into a parcel of water downstream that is flowing more slowly than the water upstream. This causes the direction of maximum local water surface slope to be diverted to one side or the other of the regional slope. This can occur when a river encounters the ocean (or a lake, or a break in slope), and can occur in many other situations as well. We analyzed various meandering systems globally, and conducted laboratory experiments under controlled conditions to determine the conditions necessary for the onset of the meander instability. The results indicate that the meander instability does not depend on sediment or erodible banks. The critical threshold for the onset of the meander instability occurs when inertial forces exceed body forces acting on the fluid such that an adverse pressure gradient arises. Better understanding of the meander instability should thus elucidate some of the

  8. ORIGINALITY - CONDITION FOR PROTECTION OF SCIENTIFIC WORKS

    Directory of Open Access Journals (Sweden)

    Viorel ROŞ

    2014-05-01

    Full Text Available The Doctrine defines originality as a combination of fancy, audacity, individuality and novelty. This ensemble of ideas meant to define originality appeals to the patents/ certificates Law for which novelty/ innovation is not enough. It shall be accompanied by inventive activity. The aim of the paper below is to clarify the question of the scientific works originality, by referring to the two appearantly contradictory norms and to their consequences over counterfeit/ imitation.

  9. Determinants of Country-of-Origin Evaluations.

    OpenAIRE

    Gurhan-Canli, Zeynep; Maheswaran, Durairaj

    2000-01-01

    Two experiments examined the factors that influence and the psychological processes that underlie country-of-origin evaluations. Subjects received attribute information that was either condensed in a single product or dispersed across several products manufactured in a country with relatively unfavorable associations. When consumers use country of origin as a basis for judgment under low motivation, or when the processing goal is to evaluate the country of origin, they focus on the country-of...

  10. 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....

  11. Flexible Proteins at the Origin of Life

    National Research Council Canada - National Science Library

    Andrew Pohorille; Michael A Wilson; Gareth Shannon

    2017-01-01

    .... How ancestral proteins attained functionality, even though they were most likely markedly smaller than their contemporary descendants, remains a major, unresolved question in the origin of life...

  12. A winding road to origin discovery.

    Science.gov (United States)

    Hamlin, Joyce L; Mesner, Larry D; Dijkwel, Pieter A

    2010-01-01

    Studies in our laboratory over the last three decades have shown that the Chinese hamster dihydrofolate reductase (DHFR) origin of replication corresponds to a broad zone of inefficient initiation sites distributed throughout the spacer between the convergently transcribed DHFR and 2BE2121 genes. It is clear from mutational analysis that none of these sites is genetically required for controlling origin activity. However, the integrity of the promoter of the DHFR gene is needed to activate the downstream origin, while the 3' processing signals prevent invasion and inactivation of the downstream origin by transcription forks. Several other origins in metazoans have been shown to correspond to zones of inefficient sites, while a different subset appears to be similar to the fixed replicators that characterize origins in S. cerevisiae and lower organisms. These observations have led us to suggest a model in which the mammalian genome is dotted with a hierarchy of degenerate, redundant, and inefficient replicators at intervals of a kilobase or less, some of which may have evolved to be highly circumscribed and efficient. The activities of initiation sites are proposed to be largely regulated by local transcription and chromatin architecture. Recently, we and others have devised strategies for identifying active origins on a genome-wide scale in order to define their distributions between fixed and dispersive origin types and to detect relationships among origins, genes, and epigenetic markers. The global pictures emerging are suggestive but far from complete and appear to be plagued by some of the same uncertainties that have led to conflicting views of individual origins in the past (particularly DHFR). In this paper, we will trace the history of origin discovery in mammalian genomes, primarily using the well-studied DHFR origin as a model, because it has been analyzed by nearly every available origin mapping technique in several different laboratories, while many

  13. An integrative approach to understanding bird origins

    National Research Council Canada - National Science Library

    Xu, Xing; Zhou, Zhonghe; Dudley, Robert; Mackem, Susan; Chuong, Cheng-Ming; Erickson, Gregory M; Varricchio, David J

    2014-01-01

    ... bird characteristics such as feathers, flight, endothermic physiology, unique strategies for reproduction and growth, and a novel pulmonary system originated among Mesozoic terrestrial dinosaurs...

  14. Country of origin effect on brand perception

    DEFF Research Database (Denmark)

    Iacob, Andreea

    2015-01-01

    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....

  15. 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... require classification, or receives any foreign government information as defined in section 1.1(d)...

  16. 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...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.505 Original classification. (a) No Commission Member or employee has...

  17. 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... EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Licenses § 478.44 Original license. (a)(1) Any person who intends to engage in business as a firearms or...

  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...

  19. 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...

  20. Prostate cancer in men of African origin.

    Science.gov (United States)

    McGinley, Kathleen F; Tay, Kae Jack; Moul, Judd W

    2016-02-01

    Men of African origin are disproportionately affected by prostate cancer: prostate cancer incidence is highest among men of African origin in the USA, prostate cancer mortality is highest among men of African origin in the Caribbean, and tumour stage and grade at diagnosis are highest among men in sub-Saharan Africa. Socioeconomic, educational, cultural, and genetic factors, as well as variations in care delivery and treatment selection, contribute to this cancer disparity. Emerging data on single-nucleotide-polymorphism patterns, epigenetic changes, and variations in fusion-gene products among men of African origin add to the understanding of genetic differences underlying this disease. On the diagnosis of prostate cancer, when all treatment options are available, men of African origin are more likely to choose radiation therapy or to receive no definitive treatment than white men. Among men of African origin undergoing surgery, increased rates of biochemical recurrence have been identified. Understanding differences in the cancer-survivorship experience and quality-of-life outcomes among men of African origin are critical to appropriately counsel patients and improve cultural sensitivity. Efforts to curtail prostate cancer screening will likely affect men of African origin disproportionately and widen the racial disparity of disease.

  1. The Origin of Life in the Universe

    OpenAIRE

    2002-01-01

    Terrestrial and extraterrestrial theories of the origin of life are discussed in the light of latest observations. The available data suggest a dual mode of origin, some of the ingredients, including possibly sugars, were brought to earth from outer space, which combined with other ingredients, such as proteins, already available on the earth leading to the formation of life.

  2. Origin and evolution of new genes

    Institute of Scientific and Technical Information of China (English)

    LI Xin; YANG Shuang; PENG Lixin; CHEN Hong; WANG Wen

    2004-01-01

    Organisms have variable genome sizes andcontain different numbers of genes. This difference demonstrates that new gene origination is a fundamental process in evolutionary biology. Though the study of the origination of new genes dated back more than half a century ago, it is not until the 1990s when the first young genejingwei was found that empirical investigation of the molecular mechanisms of origination of new genes became possible. In the recent years,several young genes were identified and the studies on these genes have greatly enriched the knowledge of this field. Yet more details in a general picture of new genes origination are to be clarified. We have developed a systematic approach to searching for young genes at the genomic level, in the hope to summarize a general pattern of the origination and evolution of new genes, such as the rate of new gene appearance, impact of new genes on their host genomes, etc.

  3. Impacts and the origin of life

    Science.gov (United States)

    Kasting, J. F.

    1990-01-01

    As living creatures, all of us have some interest in the question of how life originated. To some, the question is more religious than scientific; nonetheless, a small but dedicated group of scientists spend their careers trying to answer it from a rational standpoint. Logically, the question can be broken down into the three standard divisions of any mystery: When did life originate? Where did it originate? And how did it originate? Of these three sub-questions the last is by far the most difficult and I will make no attempt to address it here. I will however take a personal look at the two easier parts of the problem. In particular, I will outline my current view of the physical environment of the early Earth, and I will try to show how observations of other solar system bodies, especially our own Moon, provide clues as to when and where life could have originated.

  4. 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.

  5. 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...

  6. Ultrahigh Energy Cosmic Rays: A Galactic Origin?

    CERN Document Server

    Eichler, David; Kumar, Rahul; Gavish, Eyal

    2016-01-01

    It is suggested that essentially all of the UHECRs we detect, including those at the highest energy, originate in our Galaxy. It is shown that even if the density of sources decreases with Galactic radius, then the anisotropy and composition can be understood. Inward anisotropy, as recently reported by the Auger collaboration can be understood as drift along the current sheet of UHECRs originating outside the solar circle, as predicted in Kumar and Eichler (2014), while those originating within the solar circle exit the Galaxy at high latitudes.

  7. The RNA World and its origins

    Science.gov (United States)

    Schwartz, A. W.

    1995-01-01

    The theory of the "RNA World" states that the first molecular systems to display the properties of self-replication and evolution were RNA molecules. The origin of life not only depended crucially upon this event, but RNA molecules can even be viewed as the first "living" things. In recent years this theory has gained ascendancy over competing ideas and is now largely accepted by biologists as the most satisfactory explanation for the origin of life. The reasons for this development will be reviewed and the problem of the origin of the first RNA molecules will be discussed.

  8. Human embryos in the original position?

    Science.gov (United States)

    DiSilvestro, Russell

    2005-06-01

    Two different discussions in John Rawls' A Theory of Justice lead naturally to a rather conservative position on the moral status of the human embryo. When discussing paternalism, he claims that the parties in the original position would seek to protect themselves in case they end up as incapacitated or undeveloped human beings when the veil of ignorance is lifted. Since human embryos are examples of such beings, the parties in the original position would seek to protect themselves from their embryonic stages onward. When discussing the basis of equality, Rawls claims that the parties in the original position would guarantee basic rights for all those with the capacity to take part in this original position. To guarantee the basic rights of infants and young children, he goes on to interpret this capacity as a "potentiality that is ordinarily realized in due course." Since human embryos have this potentiality, they too should have basic rights.

  9. Geographical origin: meaningful reference or marketing tool?

    DEFF Research Database (Denmark)

    Hedegaard, Liselotte

    2015-01-01

    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....... In this respect, the place of origin becomes more than a point on a map. It becomes representations of the past and expectations of taste in the sense of re-tasting It is likely that the differences in consumer-perceptions reside in the interplay between origin and provenance. In France, geographical origin...... constitutes a meaningful reference to a link between food and place that represents expectations of taste and quality. In Denmark, this link is not attributed similar meaning and, hence, the difference between meaningful references and images formed through the language of marketing is less discernible...

  10. 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.

  11. Origin of the Caribbean Plate Conference

    Institute of Scientific and Technical Information of China (English)

    Keith H. James; Maria Antonieta Lorente

    2006-01-01

    @@ An international research conference, entitled "Geology of the area between North and South America, with focus on the origin of the Caribbean Plate", took place in Siguenza, Spain, from May 29-June 2, 2006.

  12. 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.

  13. An Introduction to Comets and Their Origin.

    Science.gov (United States)

    Chapman, Robert D.; Brandt, John C.

    1985-01-01

    Presents excerpts from "The Comet Book," a nontechnical primer on comets. Various topics discusses in these excerpts include such basic information about comets as their components, paths, and origins. (DH)

  14. The Evolutionary Origins of Human Generosity

    NARCIS (Netherlands)

    Komter, Aafke

    2010-01-01

    This article examines how altruism and self-interest are linked in human generosity, and what social scientists can learn from this linkage. The origins of generosity are explored by combining biological, psychological, anthropological and sociological evidence. Kinship altruism, reciprocal

  15. Originator usage control with business process slicing

    CERN Document Server

    Su, Ziyi

    2012-01-01

    Originator Control allows information providers to define the information re-dissemination condition. Combined with usage control policy, fine-grained 'downstream usage control' can be achieved, which specifies what attributes the downstream consumers should have and how data is used. This paper discusses originator usage control, paying particular attention to enterprise-level dynamic business federations. Rather than 'pre-defining' the information re-dissemination paths, our business process slicing method 'capture' the asset derivation pattern, allowing to maintain originators' policies during the full lifecycle of assets in a collaborative context. First, we propose Service Call Graph (SCG), based on extending the System Dependency Graph, to describe dependencies among partners. When SCG (and corresponding 'service call tuple' list) is built for a business process, it is analyzed to group partners into sub-contexts, according to their dependency relations. Originator usage control can be achieved focusing...

  16. "Origins of Tolerance": Reply to Crockett

    Science.gov (United States)

    Williams, J. Allen, Jr.; And Others

    1976-01-01

    Refutes the criticisms made by Harry Crockett (Social Forces 55(2), 1976) and conclude that there is no evidence in his criticisms that the interpretations of the origins of tolerance previously expressed are wrong. (AM)

  17. The Origin of Life in Comets

    Science.gov (United States)

    Napier, W. M.; Wickramasinghe, J. T.; Wickramasinghe, N. C.

    Mechanisms of interstellar panspermia have recently been identified whereby life, wherever it has originated, will disperse throughout the habitable zone of the Galaxy within a few billion years. This re-opens the question of where life originated. The interiors of comets, during their aqueous phase, seem to provide environments no less favourable for the origin of life than that of the early Earth. Their combined mass throughout the Galaxy overwhelms that of suitable terrestrial environments by about 20 powers of ten, while the lifetimes of friendly prebiotic environments within them exceeds that of localised terrestrial regions by another four or five powers of ten. We propose that the totality of comets around G-dwarf Sun-like stars offers an incomparably more probable setting for the origin of life than any that was available on the early Earth.

  18. ORIGINAL ARTICLE Shade Tree Selection and Management ...

    African Journals Online (AJOL)

    wonde

    productivity and superior cup quality. In areas of ... shade trees by farmers in improving coffee productivity and cup quality must be scientifically ... Ethiopia is the center of origin and diversity of ..... reported in some Latin American countries.

  19. Quality of Original and Biosimilar Epoetin Products

    NARCIS (Netherlands)

    Brinks, V.; Hawe, A.; Basmeleh, A.H.H.; Joachin-Rodriguez, L.; Haselberg, R.; Somsen, G.W.; Jiskoot, W.; Schellekens, H.

    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. Origins of life: a route to nanotechnology.

    Science.gov (United States)

    Sowerby, S J; Holm, N G; Petersen, G B

    2001-06-01

    The origins of life and nanotechnology are two seemingly disparate areas of scientific investigation. However, the fundamental questions of life's beginnings and the applied construction of a Drexlerian nanotechnology both share a similar problem; how did and how can self-reproducing molecular machines originate? Here we draw attention to the coincidence between nanotechnology and origins research with particular attention paid to the spontaneous adsorption and scanning tunneling microscopy investigation of purine and pyrimidine bases self-organized into monolayers, adsorbed to the surfaces of crystalline solids. These molecules which encode biological information in nucleic acids, can form supramolecular architectures exhibiting enantiomorphism with the complexity to store and encode putative protobiological information. We conclude that the application of nanotechnology to the investigation of life's origins, and vice versa, could provide a viable route to an evolution-driven synthetic life.

  1. Geochemistry and the origin of life

    Science.gov (United States)

    Kvenvolden, K. A.

    1974-01-01

    The origin of life on earth is examined from a viewpoint stressing the validity of the concept of chemical evolution. The different geological formations supporting the mechanisms of the theory are described; the stage of chemical evolution (preceding that of biological evolution) would have taken place from the time of the origin of the earth and meteorites, 4.6 billion years ago, to the early Precambrian period, about 3.2 billion years ago. Specific aspects of the problem discussed include amino acids from spark discharges and their comparison with the Murchison meteorite amino acids, the properties and theory of genesis of the carbonaceous complex within the cold Bokevelt meteorite, ammonion ion concentration in the primitive ocean, the oxygen isotope chemistry of ancient charts, the origin and rise of oxygen concentration in the earth's atmosphere, Precambrian microorganisms and evolutionary events prior to the origin of vascular plants, and biogenicity and significance of the oldest known stromatolites.

  2. The precise temporal calibration of dinosaur origins

    OpenAIRE

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

    2015-01-01

    Many hypotheses have been put forth to explain the origin and early radiation of dinosaurs, but poor age constraints for constituent fossil assemblages make these scenarios difficult to test. Using precise radioisotopic ages, we demonstrate that the temporal gap between assemblages containing only dinosaur precursors and those with the first dinosaurs was 5–10 million years shorter than previously thought. Thus, these data suggest that the origin of dinosaurs was a relatively rapid evolutiona...

  3. 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....... The results of the present study show that COO, consumer ethnocentrism and demographic characteristics have a significant impact on the consumers’ perception of the Danish beer brand Tuborg....

  4. 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....... The results of the present study show that COO, consumer ethnocentrism and demographic characteristics have a significant impact on the consumers’ perception of the Danish beer brand Tuborg....

  5. Fever of unknown origin caused by tuberculosis.

    Science.gov (United States)

    Bofinger, Jason J; Schlossberg, David

    2007-12-01

    Tuberculosis is an important cause of fever of unknown origin. Travel, age, dialysis, diabetes, birth in a country with a high prevalence of tuberculosis, and immunoincompetence are among the most salient risks. Associated physical findings, radiologic evaluation, and hematologic and endocrinologic abnormalities may provide clues to the diagnosis. Both noninvasive and invasive diagnostic modalities are reviewed. Because diagnosis may be elusive, therapeutic and diagnostic trials of antituberculous therapy should be considered in all patients with fever of unknown origin who defy diagnosis.

  6. Country of Origin: Globalised Consumer Perception

    OpenAIRE

    Steffensen, Lars Schmidt; Sørensen, Mikkel

    2013-01-01

    The project report consists of an exploratory description and a discussion illustrating the consequences of the Country of Origin effect. This is done using Malcolm Waters theoretical framework on globalisation, Adam Smith and Michael Porters theories on economic advantages in a globalised economy, and own research and theories on cognitive perception in Country of Origin effect. The qualitative empirical data collected stems interviews conducted with Royal Copenhagen consumers. The theories ...

  7. Towards art content in original graphic arts

    OpenAIRE

    2011-01-01

    Contemporary Graphic art defines numerous graphic art techniques; from classical original graphic art techniques to the new media techniques. The new media reproduction and communication capacity influences contemporary art works in such way that more attention is on non-artistic content, while artistic content with its visual efficiency becomes less important. Reproductibility is one of the non-artistic contents which plays a key role in original graphic arts, where it is a means of making o...

  8. 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

  9. The precise temporal calibration of dinosaur origins

    Science.gov (United States)

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

    2016-01-01

    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.

  10. 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.

  11. An integrative approach to understanding bird origins.

    Science.gov (United States)

    Xu, Xing; Zhou, Zhonghe; Dudley, Robert; Mackem, Susan; Chuong, Cheng-Ming; Erickson, Gregory M; Varricchio, David J

    2014-12-12

    Recent discoveries of spectacular dinosaur fossils overwhelmingly support the hypothesis that birds are descended from maniraptoran theropod dinosaurs, and furthermore, demonstrate that distinctive bird characteristics such as feathers, flight, endothermic physiology, unique strategies for reproduction and growth, and a novel pulmonary system originated among Mesozoic terrestrial dinosaurs. The transition from ground-living to flight-capable theropod dinosaurs now probably represents one of the best-documented major evolutionary transitions in life history. Recent studies in developmental biology and other disciplines provide additional insights into how bird characteristics originated and evolved. The iconic features of extant birds for the most part evolved in a gradual and stepwise fashion throughout archosaur evolution. However, new data also highlight occasional bursts of morphological novelty at certain stages particularly close to the origin of birds and an unavoidable complex, mosaic evolutionary distribution of major bird characteristics on the theropod tree. Research into bird origins provides a premier example of how paleontological and neontological data can interact to reveal the complexity of major innovations, to answer key evolutionary questions, and to lead to new research directions. A better understanding of bird origins requires multifaceted and integrative approaches, yet fossils necessarily provide the final test of any evolutionary model.

  12. 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.

  13. Phylogenetic perspectives on the origins of nodulation.

    Science.gov (United States)

    Doyle, Jeff J

    2011-11-01

    Recent refinements to the phylogeny of rosid angiosperms support the conclusion that nodulation has evolved several times in the so-called N(2)-fixing clade (NFC), and provide dates for these origins. The hypothesized predisposition that enabled the evolution of nodulation occurred approximately 100 million years ago (MYA), was retained in the various lineages that radiated rapidly shortly thereafter, and was functional in its non-nodulation role for at least an additional 30 million years in each nodulating lineage. Legumes radiated rapidly shortly after their origin approximately 60 MYA, and nodulation most likely evolved several times during this radiation. The major lineages of papilionoid legumes diverged close to the time of origin of nodulation, accounting for the diversity of nodule biology in the group. Nodulation symbioses exemplify the concept of "deep homology," sharing various homologous components across nonhomologous origins of nodulation, largely due to recruitment from existing functions, notably the older arbuscular mycorrhizal symbiosis. Although polyploidy may have played a role in the origin of papilionoid legume nodules, it did not do so in other legumes, nor did the prerosid whole-genome triplication lead directly to the predisposition of nodulation.

  14. 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.

  15. Original Sin in the Scarlet Letter

    Institute of Scientific and Technical Information of China (English)

    孙婷

    2012-01-01

    The Scarlet Letter,a representative work of Nathaniel Hawthorne,is a classical novel in American literature of 19th century.It vividly portrays people's life which was greatly influenced by Puritanism and Calvinism.And the author Nathaniel Hawthorne,who lived in that er-a,is also inevitably influenced by these mainstream thoughts.He ex-pressed his black romanticism,black view of human nature and original sin theory in almost each of his work.In his masterpiece,the Scarlet Let-ter,one important theme is original sin.This essay will first analyze where the original sin theory stems from and how it's developed by Hawthorne,and secondly will study how this theory influences the plot and major characters.

  16. Origins of Life Research: a Bibliometric Approach

    Science.gov (United States)

    Aydinoglu, Arsev Umur; Taşkın, Zehra

    2017-07-01

    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, Wȁchtershȁuser 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.

  17. 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.

  18. The origin of life from primordial planets

    Science.gov (United States)

    Gibson, Carl H.; Schild, Rudolph E.; Wickramasinghe, N. Chandra

    2011-04-01

    The origin of life and the origin of the Universe are among the most important problems of science and they might be inextricably linked. Hydro-gravitational-dynamics cosmology predicts hydrogen-helium gas planets in clumps as the dark matter of galaxies, with millions of planets per star. This unexpected prediction is supported by quasar microlensing of a galaxy and a flood of new data from space telescopes. Supernovae from stellar over-accretion of planets produce the chemicals (C, N, O, P, etc.) and abundant liquid-water domains required for first life and the means for wide scattering of life prototypes. Life originated following the plasma-to-gas transition between 2 and 20 Myr after the big bang, while planetary core oceans were between critical and freezing temperatures, and interchanges of material between planets constituted essentially a cosmological primordial soup. Images from optical, radio and infrared space telescopes suggest life on Earth was neither first nor inevitable.

  19. 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.

  20. SNC meteorites - Evidence against an asteroidal origin

    Science.gov (United States)

    Ashwal, L. D.; Warner, J. L.; Wood, C. A.

    1982-01-01

    About 1.3 billion years ago, on one or more distant planetary bodies, silicate melts formed and produced cumulate rocks which eventually made their way to earth. Nine of these rocks have been recovered. Three distinct groups are involved, including shergottites, nakhlites, and chassignites (abbreviated as SNC). The young crystallization ages and other chemical features of SNC meteorites have prompted several workers to suggest that the specimens may be samples of igneous rock, ejected from the surface of Mars during an impact event. Others have rejected the Martian origin of SNC meteorites in favor of a more traditional asteroidal parent body. The present investigation shows that the petrologic, geochemical, and isotopic evidence is inconsistent with an asteroidal origin for SNC meteorites. It is found that the characteristics of SNC meteorites argue convincingly against their origin in a planetary object as small as the largest asteroid. That these meteorites may be fragments of the Martian surface still remains the most likely possibility.

  1. Origin of extra chromosome in Patau syndrome.

    Science.gov (United States)

    Ishikiriyama, S; Niikawa, N

    1984-01-01

    Five live-born infants with Patau syndrome were studied for the nondisjunctional origin of the extra chromosome. Transmission modes of chromosomes 13 from parents to a child were determined using both QFQ- and RFA-heteromorphisms as markers, and the origin was ascertained in all of the patients. The extra chromosome had originated in nondisjunction at the maternal first meiotic division in two patients, at the maternal second meiosis in other two, and at the paternal first meiosis in the remaining one. Summarizing the results of the present study, together with those of the previous studies on a liveborn and abortuses with trisomy 13, nondisjunction at the maternal and the paternal meiosis occurred in this trisomy in the ratio of 14:3. This ratio is not statistically different from that inferred from the previous studies for Down syndrome. These findings suggest that there may be a fundamental mechanism common to the occurrence of nondisjunction in the acrocentric trisomies.

  2. The complex origin of Astyanax cavefish

    Directory of Open Access Journals (Sweden)

    Gross Joshua B

    2012-06-01

    Full Text Available Abstract Background The loss of phenotypic characters is a common feature of evolution. Cave organisms provide excellent models for investigating the underlying patterns and processes governing the evolutionary loss of phenotypic traits. The blind Mexican cavefish, Astyanax mexicanus, represents a particularly strong model for both developmental and genetic analyses as these fish can be raised in the laboratory and hybridized with conspecific surface form counterparts to produce large F2 pedigrees. As studies have begun to illuminate the genetic bases for trait evolution in these cavefish, it has become increasingly important to understand these phenotypic changes within the context of cavefish origins. Understanding these origins is a challenge. For instance, widespread convergence on similar features renders morphological characters less informative. In addition, current and past gene flow between surface and cave forms have complicated the delineation of particular cave populations. Results Past population-level analyses have sought to: 1 estimate at what time in the geological past cave forms became isolated from surface-dwelling ancestors, 2 define the extent to which cave form populations originated from a common invasion (single origin hypothesis or several invasions (multiple origin hypothesis, and 3 clarify the role of geological and climatic events in Astyanax cavefish evolution. In recent years, thanks to the combined use of morphological and genetic data, a much clearer picture has emerged regarding the origins of Astyanax cavefish. Conclusions The consensus view, based on several recent studies, is that cave forms originated from at least two distinct ancestral surface-dwelling stocks over the past several million years. In addition, each stock gave rise to multiple invasions of the subterranean biotope. The older stock is believed to have invaded the El Abra caves at least three times while the new stock separately invaded the

  3. 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

  4. The Origin of the Term 'Atlas'

    Directory of Open Access Journals (Sweden)

    Miljenko Lapaine

    2008-05-01

    Full Text Available In this paper the origin of the term 'atlas', as a bound collection of maps, is considered. It is usually thought to derive from the name of the Titan, Atlas, who was punished by being forced to bear the entire celestial sphere or universe on his shoulders. However, on the basis of research into and translation of the original Preface of Mercator's Atlas sive cosmographicae meditationes de fabrica mvndi et fabricati figvra, it has been determined that Mercator did not refer to this legend, but named his atlas for the completely different characteristics, such as wisdom, erudition and humanity, of another Atlas.

  5. Behavior of fractional diffusion at the origin.

    Science.gov (United States)

    Ryabov, Ya E

    2003-09-01

    The present work discusses the fractional diffusion equation based on the Riemann-Liouville fractional time derivatives. It was shown that the normalization conservation constraint leads to the divergency of diffusive agent concentration at the origin. This divergency implies an external source of the diffusive agent at r-->0. Thus, the Riemann-Liouville fractional time derivative implies a loss of diffusive agent mass, which is compensated for by the source of this agent at the origin. In contrast, the absence of the normalization conservation constraint does not lead to any divergences in the limit r-->0 and at the same time provides the decay of normalization.

  6. RNA catalysis and the origins of life

    Science.gov (United States)

    Orgel, Leslie E.

    1986-01-01

    The role of RNA catalysis in the origins of life is considered in connection with the discovery of riboszymes, which are RNA molecules that catalyze sequence-specific hydrolysis and transesterification reactions of RNA substrates. Due to this discovery, theories positing protein-free replication as preceding the appearance of the genetic code are more plausible. The scope of RNA catalysis in biology and chemistry is discussed, and it is noted that the development of methods to select (or predict) RNA sequences with preassigned catalytic functions would be a major contribution to the study of life's origins.

  7. Origin of "cosmic fireworks" further demystified

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Teaning up with colleagues from Europe, Japan, and US, Dr. DENG Jinsong from the National Astronomical Observatories at CAS (NAOC) has made fresh progress in revealing the mechanism behind the origin of the long-duration gamma-ray bursts (GRBs), which are short-lived,localized, and intense bursts of γradiation originating outside our Milky Way galaxy from sources yet to be understood by astronomers.The work entitled "A neutron-stardriven X-ray flash associated with supernova SN 2006aj" was reported in the August 31 issue of Nature.

  8. [Fever of unknown origin in adults].

    Science.gov (United States)

    Lambertucci, José Roberto; Avila, Renata Eliane de; Voieta, Izabela

    2005-01-01

    Fever of unknown origin has been defined as axillary temperature higher than 37.8 degrees C on several occasions, persisting without diagnosis for at least 3 weeks in spite of at least 1 week's investigation in hospital. Lately, the definition has been modified and extended to reflect evolutionary changes in clinical practice. In response to this new evolving environment, cases of fever of unknown origin are currently classified as: classic, nosocomial, in neutropenia, and human immunodeficiency virus-related. The objective of our review was to try and define and to update the information on the subject.

  9. Fever of unknown origin (FUO) revised

    OpenAIRE

    Unger, Manuel; Karanikas, Georgios; Kerschbaumer, Andreas; Winkler, Stefan; Aletaha, Daniel

    2016-01-01

    Summary Fever of unknown origin (FUO) was originally characterised in 1961 by Petersdorf and Beeson as a disease condition of temperature exceeding 38.3 °C on at least three occasions over a period of at least three weeks, with no diagnosis made despite one week of inpatient investigation. However, since underlying diseases are often reported for classical FUO, these presentations may not be considered to be of “unknown origin”. Rather, the aetiology of prolonged fever may resolve, or not res...

  10. Origin of the cell - Experiments and premises

    Science.gov (United States)

    Fox, S. W.

    1973-01-01

    Theories and component concepts of the origin of life, i.e., primordial life, have emerged from (1) constructionistic studies on model materials and systems, and (2) reductionistic studies of contemporary cells. The resultant views conflict in a number of aspects; many of the differences are analyzed in this article. Constructionistic experiments are appropriate to asking questions about origins since they are in the same direction as evolution itself. These experiments have revealed self-ordering properties and associated emergent functions, which were not predictable.

  11. 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.

  12. John Haught on original sin: A conversation

    Directory of Open Access Journals (Sweden)

    Ernst M. Conradie

    2016-05-01

    Full Text Available This article engages with John Haught’s views on original sin. It offers a brief orientation todiscourse on sin in the context of theological debates on human evolution. This is followed bya thick description of Haught’s so-called note on original sin. A series of five observations andquestions regarding Haught’s position is offered. It is observed that Haught’s way of tellingthe story of sin and salvation follows a classic Roman Catholic plot, namely one based on graceelevating nature. This is contrasted with the more typically reformed plot of restoration.

  13. The physical origin of hydrophobic effects

    Science.gov (United States)

    Sun, Qiang

    2017-03-01

    From the structural studies on water and air/water interface, hydration free energy is derived, and used to investigate the origin of hydrophobic effects. As a solute is dissolved into water, hydration free energy increases, and is divided into initial and hydrophobic solvation processes. In the initial process, hydration free energy is dominated by hydrogen bonding in interfacial water (topmost water layer at solute/water interface). For hydrophobic process, hydration free energy is related to the hydrogen bonding in bulk and interfacial water. Therefore, hydrophobic effects originate from the structural competition between hydrogen bonding in bulk water and that in interfacial water.

  14. Lunar origin from impact on the Earth

    Science.gov (United States)

    Stevenson, D. J.

    1984-01-01

    All theories of lunar origin involve events or processes which seemingly have low efficiencies or low probabilities or both. An impact-triggered fission lunar origin is presented. If the impact ejecta (a mixture of target and projectile) leave the impact site ballistically and are subsequently acted upon only by the gravity field of a spherical Earth, then the ejecta either reimpacts the Earth or escapes on a hyperbolic trajectory. Hence the need for a second burn. Three possible resolutions are considered: pressure gradient acceleration, non-central gravity, and viscous spreading.

  15. The origin and destiny of our universe

    Science.gov (United States)

    Kolb, Rocky

    2005-04-01

    The discoveries of Albert Einstein rank among humanity's greatest achievements. Although his theory of gravity is the framework for understanding the origin and destiny of our Universe, it does not really tell us how or why the universe began, or how or if it will end. Recent developments and discoveries have shed new light on these issues. I will describe how observations and theory can shed light on what powered the big bang and the mysterious dark energy that is pulling the Universe apart. Perhaps we are close to completing Einstein's legacy and unraveling the cosmic mysteries of our origin and destiny.

  16. 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.

  17. 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

  18. 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.

  19. 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 in the Un......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...

  20. Noisy clues to the origin of life.

    Science.gov (United States)

    Krakauer, David C; Sasaki, Akira

    2002-12-01

    The origin of stable self-replicating molecules represents a fundamental obstacle to the origin of life. The low fidelity of primordial replicators places restrictions on the quantity of information encoded in a primitive nucleic acid alphabet. Further difficulties for the origin of life are the role of drift in small primordial populations, reducing the rate of fixation of superior replicators, and the hostile conditions increasing developmental noise. Thus, mutation, noise and drift are three different stochastic effects that are assumed to make the evolution of life improbable. Here we show, to the contrary, how noise present in hostile early environments can increase the probability of faithful replication, by amplifying selection in finite populations. Noise has negative consequences in infinite populations, whereas in finite populations, we observe a synergistic interaction among noise sources. Hence, two factors formerly considered inimical to the origin of life-developmental noise and drift in small populations-can in combination give rise to conditions favourable to robust replication.

  1. 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...

  2. Replication Origin Specification Gets a Push.

    Science.gov (United States)

    Plosky, Brian S

    2015-12-03

    During the gap between G1 and S phases when replication origins are licensed and fired, it is possible that DNA translocases could disrupt pre-replicative complexes (pre-RCs). In this issue of Molecular Cell, Gros et al. (2015) find that pre-RCs can be pushed along DNA and retain the ability to support replication.

  3. [Schopenhauer as the originator of Freudian metapsychology].

    Science.gov (United States)

    Gödde, G

    1991-11-01

    The influence of 19th century philosophy on Freud's thought is to this day underestimated in comparison with the influence of the scientific theories. Gödde vindicates Max Horkheimer's proposition that Freud was "in certain respects a successor to Schopenhauer" even though Freud knew Schopenhauer (and Nietzsche) through secondary literature rather than through the original writings.

  4. Researching with Original Sources in Culture Studies.

    Science.gov (United States)

    Carter, Douglas

    1997-01-01

    Describes the method employed for scholarship that involves the analysis of original unpublished scripts. A professional-development grant provided an opportunity to travel to a university archive to read primary research materials unavailable through conventional means, and to develop a detailed analysis of selected works by Ray Bradbury,…

  5. Search for the Origin of Life

    Science.gov (United States)

    Brown, R. D.

    1975-01-01

    Presents various ideas on the origin of life including very early ideas, Oparin's view, and an alternative view related to carbonaceous chondrites. Outlines one currently tenable hypothesis in the formation of the solar system and explains the method involved in detecting polyatomic molecules in dark nebulae. (GS)

  6. Tracing program transformations with string origins

    NARCIS (Netherlands)

    Inostroza Valdera, P.A.; Storm, T. van der; Erdweg, S.

    2014-01-01

    Program transformations play an important role in domain-specific languages and model-driven development. Tracing the execution of such transformations has well-known benefits for debugging, visualization and error reporting. In this paper we introduce string origins as a lightweight, generic and po

  7. Origins of food crops connect countries worldwide

    NARCIS (Netherlands)

    Khoury, Colin K.; 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 hav

  8. Cosmic Ray Origin, Acceleration and Propagation

    CERN Document Server

    Baring, M G

    1999-01-01

    This paper summarizes highlights of the OG3.1, 3.2 and 3.3 sessions of the XXVIth International Cosmic Ray Conference in Salt Lake City, which were devoted to issues of origin/composition, acceleration and propagation.

  9. 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......, and the orientation of comparative political economy in political science and sociology....

  10. Search for the Origin of Life

    Science.gov (United States)

    Brown, R. D.

    1975-01-01

    Presents various ideas on the origin of life including very early ideas, Oparin's view, and an alternative view related to carbonaceous chondrites. Outlines one currently tenable hypothesis in the formation of the solar system and explains the method involved in detecting polyatomic molecules in dark nebulae. (GS)

  11. 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…

  12. [Diagnostic approach to fever of unknown origin

    NARCIS (Netherlands)

    Bleeker-Rovers, C.P.; Meer, J.W.M. van der

    2008-01-01

    Nowadays, fever of unknown origin (FUO) is generally defined as a fever higher than 38-3 degrees C lasting for a period of at least three weeks, in which no definitive diagnosis has been made after a number of obligatory tests. A diagnostic algorithm is proposed in which history taking, physical

  13. Origin of organic molecules and biomolecular homochirality.

    Science.gov (United States)

    Podlech, J

    2001-01-01

    Theories about the origin of biomolecular homochirality, which seems to be a prerequisite for the creation of life, are discussed. First, possible terrestrial and extraterrestrial sources of organic molecules are outlined. Then, mechanisms for the formation of enantiomerically enriched compounds and for the amplification of their chirality are described.

  14. 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...

  15. Digital television revolution origins to outcomes

    CERN Document Server

    Starks, Michael

    2013-01-01

    This account of the global switch to digital television, from its origins to its emerging outcomes, provides an understanding of how digital television is converging with the Internet. It pictures a future in which the democratic role of the media, freedom of expression and democratic participation can be enhanced.

  16. Plastid origin: who, when and why?

    Directory of Open Access Journals (Sweden)

    Chuan Ku

    2014-12-01

    Full Text Available The origin of plastids is best explained by endosymbiotic theory, which dates back to the early 1900s. Three lines of evidence based on protein import machineries and molecular phylogenies of eukaryote (host and cyanobacterial (endosymbiont genes point to a single origin of primary plastids, a unique and important event that successfully transferred two photosystems and oxygenic photosynthesis from prokaryotes to eukaryotes. The nature of the cyanobacterial lineage from which plastids originated has been a topic of investigation. Recent studies have focused on the branching position of the plastid lineage in the phylogeny based on cyanobacterial core genes, that is, genes shared by all cyanobacteria and plastids. These studies have delivered conflicting results, however. In addition, the core genes represent only a very small portion of cyanobacterial genomes and may not be a good proxy for the rest of the ancestral plastid genome. Information in plant nuclear genomes, where most genes that entered the eukaryotic lineage through acquisition from the plastid ancestor reside, suggests that heterocyst-forming cyanobacteria in Stanier’s sections IV and V are most similar to the plastid ancestor in terms of gene complement and sequence conservation, which is in agreement with models suggesting an important role of nitrogen fixation in symbioses involving cyanobacteria. Plastid origin is an ancient event that involved a prokaryotic symbiont and a eukaryotic host, organisms with different histories and genome evolutionary processes. The different modes of genome evolution in prokaryotes and eukaryotes bear upon our interpretations of plastid phylogeny.

  17. 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

  18. Standardized Tests and Froebel's Original Kindergarten Model

    Science.gov (United States)

    Jeynes, William H.

    2006-01-01

    The author argues that American educators rely on standardized tests at too early an age when administered in kindergarten, particularly given the original intent of kindergarten as envisioned by its founder, Friedrich Froebel. The author examines the current use of standardized tests in kindergarten and the Froebel model, including his emphasis…

  19. 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.

  20. Origins of molecular biology in Japan.

    Science.gov (United States)

    Obayashi, M

    1986-06-01

    The purpose of this paper is to discuss the origins of molecular biology in Japan. Japanese molecular biology does not have a long history since it started only after World War II. Especially, molecular genetics which uses "bacteriophage" had hardly been studied before the war and only a few scientists were interested in it immediately after the war. This is one of the origins of molecular biology in Japan. But there are other origins, one of which is the group formed by biologists, biochemists and physicists interested in nucleic acids. This group also started just after the war. Still another origin is the group of enzymologists. Enzymology was one of the main subjects of biochemistry from before the war. In Japan, biochemistry developed in conjunction with the medical and agricultural sciences from the pre-war era. These played an important role in introducing molecular biology from Europe and the United States after the war. A historical study of the development of molecular biology in Japan, comparing it with the history of molecular biology in Europe and the United States, should contribute to the elucidation of the features of the history of molecular biology in Japan.

  1. Genomics and the origin of species

    NARCIS (Netherlands)

    Seehausen, Ole; Butlin, Roger K.; Keller, Irene; Wagner, Catherine E.; Boughman, Janette W.; Hohenlohe, Paul A.; Peichel, Catherine L.; Saetre, Glenn-Peter; Bank, Claudia; Brännström, Åke; Brelsford, Alan; Clarkson, Chris S.; Eroukhmanoff, Fabrice; Feder, Jeffrey L.; Fischer, Martin C.; Foote, Andrew D.; Franchini, Paolo; Jiggins, Chris D.; Jones, Felicity C.; Lindholm, Anna K.; Lucek, Kay; Maan, Martine E.; Marques, David A.; Martin, Simon H.; Matthews, Blake; Meier, Joana I.; Möst, Markus; Nachman, Michael W.; Nonaka, Etsuko; Rennison, Diana J.; Schwarzer, Julia; Watson, Eric T.; Westram, Anja M.; Widmer, Alex

    Speciation is a fundamental evolutionary process, the knowledge of which is crucial for understanding the origins of biodiversity. Genomic approaches are an increasingly important aspect of this research field. We review current understanding of genome-wide effects of accumulating reproductive

  2. The early origins of the logit model

    NARCIS (Netherlands)

    Cramer, J.S.

    2004-01-01

    This paper describes the origins of the logistic function and its history up to its adoption in bio-assay and the beginning of its wider acceptance in statistics, ca. 1950. The function was probably first invented in 1838 to describe population growth by the Belgian mathematician Verhulst, who gave

  3. 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.…

  4. On the Origin of Hypervelocity Stars

    Science.gov (United States)

    Yu, Q.; Lu, Y.

    2011-05-01

    Hypervelocity stars (HVSs) moving in the Galactic halo are mainly B-type stars with origin of their progenitors unknown. OB stars are also populated in the Galactic Center (GC), with many being hosted in a clockwise rotating young stellar (CWS) disk within half a parsec from the central massive black hole (MBH) and their formation remaining puzzles. We find that the majority of the detected HVSs are spatially correlated with the plane of the stellar disk. By demonstrating that HVSs can well memorize the injecting direction of their progenitors, we conclude that most of the HVSs probably originate from the CWS disk. Our results not only confirm the GC origin of HVSs but also imply that the central disk should persist or be frequently rejuvenated over the past 200 Myr, which adds a new challenge to the stellar disk formation and provides insights to the longstanding problem of gas fueling into MBHs. A future survey of HVSs in the southern hemisphere will provide a check for the origin of HVSs.

  5. Genomics and the origin of species

    NARCIS (Netherlands)

    Seehausen, Ole; Butlin, Roger K.; Keller, Irene; Wagner, Catherine E.; Boughman, Janette W.; Hohenlohe, Paul A.; Peichel, Catherine L.; Saetre, Glenn-Peter; Bank, Claudia; Brännström, Åke; Brelsford, Alan; Clarkson, Chris S.; Eroukhmanoff, Fabrice; Feder, Jeffrey L.; Fischer, Martin C.; Foote, Andrew D.; Franchini, Paolo; Jiggins, Chris D.; Jones, Felicity C.; Lindholm, Anna K.; Lucek, Kay; Maan, Martine E.; Marques, David A.; Martin, Simon H.; Matthews, Blake; Meier, Joana I.; Möst, Markus; Nachman, Michael W.; Nonaka, Etsuko; Rennison, Diana J.; Schwarzer, Julia; Watson, Eric T.; Westram, Anja M.; Widmer, Alex

    2014-01-01

    Speciation is a fundamental evolutionary process, the knowledge of which is crucial for understanding the origins of biodiversity. Genomic approaches are an increasingly important aspect of this research field. We review current understanding of genome-wide effects of accumulating reproductive isola

  6. Original Symbols in Episode Four of Ulysses

    Institute of Scientific and Technical Information of China (English)

    李晨

    2015-01-01

    Ulysses is considered to be the masterpiece of James Joyce's literary accomplishments.Many symbols are applied in this novel,of which the implied meanings are obscure but significant.This paper is intended to make a detailed analysis of the original symbols in the fourth episode of Ulysses.

  7. Original Symbols in Episode Four of Ulysses

    Institute of Scientific and Technical Information of China (English)

    李晨

    2015-01-01

    Ulysses is considered to be the masterpiece of James Joyce’s literary accomplishments.Many symbols are applied in this novel,of which the implied meanings are obscure but significant.This paper is intended to make a detailed analysis of the original symbols in the fourth episode of Ulysses.

  8. Genomics and the origin of species

    NARCIS (Netherlands)

    Seehausen, Ole; Butlin, Roger K.; Keller, Irene; Wagner, Catherine E.; Boughman, Janette W.; Hohenlohe, Paul A.; Peichel, Catherine L.; Saetre, Glenn-Peter; Bank, Claudia; Brännström, Åke; Brelsford, Alan; Clarkson, Chris S.; Eroukhmanoff, Fabrice; Feder, Jeffrey L.; Fischer, Martin C.; Foote, Andrew D.; Franchini, Paolo; Jiggins, Chris D.; Jones, Felicity C.; Lindholm, Anna K.; Lucek, Kay; Maan, Martine E.; Marques, David A.; Martin, Simon H.; Matthews, Blake; Meier, Joana I.; Möst, Markus; Nachman, Michael W.; Nonaka, Etsuko; Rennison, Diana J.; Schwarzer, Julia; Watson, Eric T.; Westram, Anja M.; Widmer, Alex

    2014-01-01

    Speciation is a fundamental evolutionary process, the knowledge of which is crucial for understanding the origins of biodiversity. Genomic approaches are an increasingly important aspect of this research field. We review current understanding of genome-wide effects of accumulating reproductive isola

  9. ENTEROBACTERICEAE OF ANIMAL ORIGIN: A REVIEW,!,

    African Journals Online (AJOL)

    'Tropical Animal Health and Production Research Lab., Department of Animal ... The emergence of anti-microbial resistant strains in the treatment of bacterial ... Current information on the spread of pathogenic and commensal bacteria of animal origin ..... bio-typing, phage typing and ... published reports as well as current.

  10. Tanzanian food origins and protected geographical indications

    DEFF Research Database (Denmark)

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

    2016-01-01

    and sovereignty and quality within an efficient marketing system with the availability of government support, hence the need to identify key candidates for GI certification. Five Tanzanian origin products were selected from 14 candidate agricultural products through a scoping study. Rice from Kyela, Aloe vera...

  11. The Evolutionary Origins of Human Generosity

    NARCIS (Netherlands)

    Komter, Aafke

    2010-01-01

    This article examines how altruism and self-interest are linked in human generosity, and what social scientists can learn from this linkage. The origins of generosity are explored by combining biological, psychological, anthropological and sociological evidence. Kinship altruism, reciprocal altruism

  12. Action Research: Its Origins and Early Application.

    Science.gov (United States)

    Cook, Stuart W.

    This paper contains informal remarks on action research in social psychology from its post World War II origins to its current status. Kurt Lewin first described action research in the 1946 article, "Action Research and Minority Problems," as a three-step process of program planning, program execution, and follow-up evaluation. Ronald Lippitt and…

  13. Prevolutionary dynamics and the origin of evolution.

    Science.gov (United States)

    Nowak, Martin A; Ohtsuki, Hisashi

    2008-09-30

    Life is that which replicates and evolves. The origin of life is also the origin of evolution. A fundamental question is when do chemical kinetics become evolutionary dynamics? Here, we formulate a general mathematical theory for the origin of evolution. All known life on earth is based on biological polymers, which act as information carriers and catalysts. Therefore, any theory for the origin of life must address the emergence of such a system. We describe prelife as an alphabet of active monomers that form random polymers. Prelife is a generative system that can produce information. Prevolutionary dynamics have selection and mutation, but no replication. Life marches in with the ability of replication: Polymers act as templates for their own reproduction. Prelife is a scaffold that builds life. Yet, there is competition between life and prelife. There is a phase transition: If the effective replication rate exceeds a critical value, then life outcompetes prelife. Replication is not a prerequisite for selection, but instead, there can be selection for replication. Mutation leads to an error threshold between life and prelife.

  14. On the origin of metabolic pathways

    Science.gov (United States)

    Lazcano, A.; Miller, S. L.; Bada, J. L. (Principal Investigator)

    1999-01-01

    The heterotrophic theory of the origin of life is the only proposal available with experimental support. This comes from the ease of prebiotic synthesis under strongly reducing conditions. The prebiotic synthesis of organic compounds by reduction of CO(2) to monomers used by the first organisms would also be considered an heterotrophic origin. Autotrophy means that the first organisms biosynthesized their cell constituents as well as assembling them. Prebiotic synthetic pathways are all different from the biosynthetic pathways of the last common ancestor (LCA). The steps leading to the origin of the metabolic pathways are closer to prebiotic chemistry than to those in the LCA. There may have been different biosynthetic routes between the prebiotic and the LCAs that played an early role in metabolism but have disappeared from extant organisms. The semienzymatic theory of the origin of metabolism proposed here is similar to the Horowitz hypothesis but includes the use of compounds leaking from preexisting pathways as well as prebiotic compounds from the environment.

  15. Epicardial origin of cardiac CFU-Fs.

    Science.gov (United States)

    Slukvin, Igor I

    2011-12-02

    The epicardium has been recognized as a source of cardiovascular progenitors during embryogenesis and postnatal life. In this issue of Cell Stem Cell, Chong et al. (2011) identify cardiac CFU-Fs as cardiac-resident cells of epicardial origin with broad multilineage differentiation potential.

  16. 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).

  17. [Medical anthropology evidences on the Pishtaco origin].

    Science.gov (United States)

    de Pribyl, Rosario

    2010-03-01

    This paper will contribute to the scientific development of a new approach on the pishtaco in Peru by means of medical anthropological analysis. The model emphasizes presentation and analysis of historical, pharmaceutical, and anthropological evidence supporting use of human tissues with specific medical goals in Peruvian and European regions. We can find the origin of this phenomenon around the sixteen and seventeen centuries in Europe: The pishtaco has no an Andean origin. The methodology and main conclusions of this paper could provide to the scientific community an alternative perspective to the conventional anthropological and ethnological research, as an example of a medical anthropological analysis of the pishtaco character. Professionals involved in intercultural health projects could have a new insight on this issue thanks to these results. They will obtain an adequate historical-cultural context for the interpretation and understanding of people and native communities' beliefs about health, body and medical systems.

  18. Origin of Hawking Radiation: Firewall or Atmosphere?

    CERN Document Server

    Kim, Wontae

    2016-01-01

    The Unruh vacuum not admitting any outgoing flux at the horizon implies that the origin of the outgoing Hawking radiation would be the atmosphere of a near-horizon quantum region without resort to the firewall; however, the existence of the firewall of superplanckian excitations at the horizon might be supported by the infinite Tolman temperature of the infinitely blueshifted Hawking temperature at the horizon. Using an exactly soluble model, we show that the firewall necessarily emerges out of the Unruh vacuum such that the Tolman temperature in the Unruh vacuum is divergent in essence due to the infinitely blueshifted negative ingoing flux crossing the horizon rather than the outgoing flux. It is also shown that the outgoing Hawking radiation in the Unruh vacuum indeed originates from the atmosphere, not just at the horizon, which is of no relevance to the infinite blueshift. Consequently, we find that the firewall induced from the infinite Tolman temperature and the Hawking radiation coming from the atmosp...

  19. 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.

  20. On the origins of psychoanalytic psychohistory.

    Science.gov (United States)

    Pietikainen, Petteri; Ihanus, Juhani

    2003-05-01

    This article examines the origins and early development of psychoanalytically inspired psychohistory from the late 1950s to the early 1970s. It focuses on Erik H. Erikson, Bruce Mazlish, and Robert Jay Lifton and illustrates their contributions to psychoanalytic psychohistory. Erikson, Mazlish, and Lifton were core members of the Wellfleet group, a research project originally funded by the American Academy of Arts and Sciences in 1965 to conceptualize the foundation of psychohistory. The article gives an account of the early history of the Wellfleet group and argues for specific historical reasons to explain why psychoanalytic psychohistory emerged on the East Coast of the United States in the late 1950s and early 1960s. A critique of the Wellfleet group in unpublished correspondence of Erich Fromm and David Riesman is also discussed.

  1. The burrowing origin of modern snakes

    Science.gov (United States)

    Yi, Hongyu; Norell, Mark A.

    2015-01-01

    Modern snakes probably originated as habitat specialists, but it controversial unclear whether they were ancestrally terrestrial burrowers or marine swimmers. We used x-ray virtual models of the inner ear to predict the habit of Dinilysia patagonica, a stem snake closely related to the origin of modern snakes. Previous work has shown that modern snakes perceive substrate vibrations via their inner ear. Our data show that D. patagonica and modern burrowing squamates share a unique spherical vestibule in the inner ear, as compared with swimmers and habitat generalists. We built predictive models for snake habit based on their vestibular shape, which estimated D. patagonica and the hypothetical ancestor of crown snakes as burrowers with high probabilities. This study provides an extensive comparative data set to test fossoriality quantitatively in stem snakes, and it shows that burrowing was predominant in the lineages leading to modern crown snakes. PMID:26702436

  2. 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...... and sovereignty and quality within an efficient marketing system with the availability of government support, hence the need to identify key candidates for GI certification. Five Tanzanian origin products were selected from 14 candidate agricultural products through a scoping study. Rice from Kyela, Aloe vera...... area, product quality perceived by the consumer in terms of taste, flavour, texture, aroma, appearance (colour, size) and perceptions of links between geography related factors (soil, land weather characteristics) and product qualities. A qualitative case study analysis was done for each of the (five...

  3. Fever of unknown origin in returning travellers.

    Science.gov (United States)

    Korzeniewski, Krzysztof; Gaweł, Bartłomiej; Krankowska, Dagny; Wasilczuk, Katarzyna

    2015-01-01

    The aim of the article is to discuss issues associated with the occurrence of febrile illnesses in leisure and business travellers, with a particular emphasis on fevers of unknown origin (FUO). FUO, apart from diarrhoeas, respiratory tract infections and skin lesions, are one of the most common health problems in travellers to tropical and subtropical countries. FUO are manifestations of various diseases, typically of infectious or invasive aetiology. In one out of 3 cases, the cause of a fever in travellers returning from the hot climate zone is malaria, and therefore diagnostic tests should first aim at ruling out this specific disease entity. Other illnesses with persistent fever include dengue, enteric fever, viral hepatitis A, bacterial diarrhoeas and rickettsioses. Fever may also occur in travellers suffering from diseases of non-tropical origin, e.g. cosmopolitan respiratory tract or urinary tract infections, also, fever may coexist with other illnesses or injuries (skin rashes, bites, burns).

  4. 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.

  5. The burrowing origin of modern snakes.

    Science.gov (United States)

    Yi, Hongyu; Norell, Mark A

    2015-11-01

    Modern snakes probably originated as habitat specialists, but it controversial unclear whether they were ancestrally terrestrial burrowers or marine swimmers. We used x-ray virtual models of the inner ear to predict the habit of Dinilysia patagonica, a stem snake closely related to the origin of modern snakes. Previous work has shown that modern snakes perceive substrate vibrations via their inner ear. Our data show that D. patagonica and modern burrowing squamates share a unique spherical vestibule in the inner ear, as compared with swimmers and habitat generalists. We built predictive models for snake habit based on their vestibular shape, which estimated D. patagonica and the hypothetical ancestor of crown snakes as burrowers with high probabilities. This study provides an extensive comparative data set to test fossoriality quantitatively in stem snakes, and it shows that burrowing was predominant in the lineages leading to modern crown snakes.

  6. Magnetohydrodynamic Origin of Jets from Accretion Disks

    CERN Document Server

    Lovelace, R V E; Koldoba, A V

    1999-01-01

    A review is made of recent magnetohydrodynamic (MHD) theory and simulations of origin of jets from accretion disks. Many compact astrophysical objects emit powerful, highly-collimated, oppositely directed jets. Included are the extra galactic radio jets of active galaxies and quasars, and old compact stars in binaries, and emission line jets in young stellar objects. It is widely thought that these different jets arise from rotating, conducting accretion disks threaded by an ordered magnetic field. The twisting of the magnetic field by the rotation of the disk drives the jets by magnetically extracting matter, angular momentum, and energy from the accretion disk. Two main regimes have been discussed theoretically, hydromagnetic winds which have a significant mass flux, and Poynting flux jets where the mass flux is negligible. Over the past several years, exciting new developments on models of jets have come from progress in MHD simulations which now allow the study of the origin - the acceleration and collima...

  7. Cholangiocarcinomas can originate from hepatocytes in mice.

    Science.gov (United States)

    Fan, Biao; Malato, Yann; Calvisi, Diego F; Naqvi, Syed; Razumilava, Nataliya; Ribback, Silvia; Gores, Gregory J; Dombrowski, Frank; Evert, Matthias; Chen, Xin; Willenbring, Holger

    2012-08-01

    Intrahepatic cholangiocarcinomas (ICCs) are primary liver tumors with a poor prognosis. The development of effective therapies has been hampered by a limited understanding of the biology of ICCs. Although ICCs exhibit heterogeneity in location, histology, and marker expression, they are currently thought to derive invariably from the cells lining the bile ducts, biliary epithelial cells (BECs), or liver progenitor cells (LPCs). Despite lack of experimental evidence establishing BECs or LPCs as the origin of ICCs, other liver cell types have not been considered. Here we show that ICCs can originate from fully differentiated hepatocytes. Using a mouse model of hepatocyte fate tracing, we found that activated NOTCH and AKT signaling cooperate to convert normal hepatocytes into biliary cells that act as precursors of rapidly progressing, lethal ICCs. Our findings suggest a previously overlooked mechanism of human ICC formation that may be targetable for anti-ICC therapy.

  8. Origin of the Autophagosomal Membrane in Plants

    Directory of Open Access Journals (Sweden)

    Xiaohong Zhuang

    2016-11-01

    Full Text Available During autophagy, cargo molecules destined for degradation are sequestrated into a double membrane structure called autophagosome, which subsequently fuses with the vacuole. An isolation membrane structure (also called the phagophore initiates from the platform termed PAS (phagophore assembly site or preautophagosomal structure, which then elongates and expands to become the completed autophagosome. The origin of the membrane for autophagosome formation has been extensively investigated but remains an enigma in the field of autophagy. In yeast and mammalian cells multiple membrane sources have been suggested to contribute to autophagosome formation at different steps, from initiation through expansion and maturation. Recent studies in plants have provided a significant advance in our understanding of the conserved role of autophagy and the underlying mechanism for autophagosome formation. Here, we will discuss and evaluate these new findings on autophagosome formation in plants, with a particular focus on the origin of plant autophagosomal membranes.

  9. The Origin of Life from Primordial Planets

    CERN Document Server

    Gibson, Carl H; Wickramasinghe, N C

    2010-01-01

    The origin of life and the origin of the universe represent two of the most important problems of science. Both are resolved by hydro-gravitational dynamics (HGD) cosmology (Gibson 1996, Schild 1996, Gibson 2009ab), which predicts frozen primordial hydrogen-helium gas planets in clumps as the dark matter of galaxies. Merging Earth-mass planets formed stars, moons and comets to incubate and cosmically seed the first life. Cometary panspermia (Hoyle and Wickramasinghe 1981, 1982; Wickramasinghe et al. 2009) occurs naturally by HGD mechanisms. Comets and moons are fragments from mergers of stardust covered frozen gas planets in their step-wise growth to star mass. Supernovae from stellar over-accretion of planets produce stardust (C, N, O, P etc.) chemical fertilizer. Planets collect this infected radioactive dust gravitationally, to provide liquid water domains in contact with life nutrients seeded with life prototypes. The first mutating, evolving, life from HGD likely occurred promptly, following the plasma t...

  10. Carbonaceous chondrites and the origin of life

    Science.gov (United States)

    Hartman, Hyman; Sweeney, Michael A.; Kropp, Michael A.; Lewis, John S.

    1993-01-01

    Organic matter in carbonaceous chondrites can be separated into three fractions. The first component, the fraction that is insoluble in chloroform and methanol, has a part which is of interstellar origin. The other two fractions (chloroform-soluble hydrocarbons and methanol-soluble polar organics) are hypothesized to have been synthesized on a planetoid body. We propose that the polar organics, i.e., amino acids, were synthesized close to its surface by the radiolysis of hydrocarbons and ammonium carbonate in a liquid water environment. Some hydrocarbons may have been synthesized by a Fischer-Tropsch mechanism in the interior of the body. Ferrous ion acted as a protection against back reactions. The simultaneous synthesis of iron-rich clays with the polar organics may be indicative of events related to the origin of life on Earth.

  11. Origin of the earth's ocean basins

    Science.gov (United States)

    Frey, H.

    1977-01-01

    The earth's original ocean basins are proposed to be mare-type basins produced 4 billion y.a. by the flux of asteroid-sized objects responsible for the lunar mare basins. Scaling upward from the observed number of lunar basins for the greater capture cross-section and impact velocity of the earth indicates that at least 50% of an original global crust would have been converted to basin topography. These basins were flooded by basaltic liquids in times short compared to the isostatic adjustment time for the basin. The modern crustal dichotomy (60% oceanic, 40% continental crust) was established early in the history of the earth, making possible the later onset of plate tectonic processes. These later processes have subsequently reworked, in several cycles, principally the oceanic parts of the earth's crust, changing the configuration of the continents in the process. Ocean basins (and oceans themselves) may be rare occurrences on planets in other star systems.

  12. Open Questions on the Origin of Eukaryotes.

    Science.gov (United States)

    López-García, Purificación; Moreira, David

    2015-11-01

    Despite recent progress, the origin of the eukaryotic cell remains enigmatic. It is now known that the last eukaryotic common ancestor was complex and that endosymbiosis played a crucial role in eukaryogenesis at least via the acquisition of the alphaproteobacterial ancestor of mitochondria. However, the nature of the mitochondrial host is controversial, although the recent discovery of an archaeal lineage phylogenetically close to eukaryotes reinforces models proposing archaea-derived hosts. We argue that, in addition to improved phylogenomic analyses with more comprehensive taxon sampling to pinpoint the closest prokaryotic relatives of eukaryotes, determining plausible mechanisms and selective forces at the origin of key eukaryotic features, such as the nucleus or the bacterial-like eukaryotic membrane system, is essential to constrain existing models.

  13. 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.

  14. 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.

  15. 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.

  16. Identifying the seasonal origins of human campylobacteriosis.

    Science.gov (United States)

    Strachan, N J C; Rotariu, O; Smith-Palmer, A; Cowden, J; Sheppard, S K; O'Brien, S J; Maiden, M C J; Macrae, M; Bessell, P R; Matthews, L; Reid, S W J; Innocent, G T; Ogden, I D; Forbes, K J

    2013-06-01

    Human campylobacteriosis exhibits a distinctive seasonality in temperate regions. This paper aims to identify the origins of this seasonality. Clinical isolates [typed by multi-locus sequence typing (MLST)] and epidemiological data were collected from Scotland. Young rural children were found to have an increased burden of disease in the late spring due to strains of non-chicken origin (e.g. ruminant and wild bird strains from environmental sources). In contrast the adult population had an extended summer peak associated with chicken strains. Travel abroad and UK mainland travel were associated with up to 17% and 18% of cases, respectively. International strains were associated with chicken, had a higher diversity than indigenous strains and a different spectrum of MLST types representative of these countries. Integrating empirical epidemiology and molecular subtyping can successfully elucidate the seasonal components of human campylobacteriosis. The findings will enable public health officials to focus strategies to reduce the disease burden.

  17. Relation of Origins of Primitive Chaos

    CERN Document Server

    Ogasawara, Yoshihito

    2014-01-01

    A new concept, primitive chaos, was proposed, as a concept closely related to the fundamental problems of sciences themselves such as determinism, causality, free will, predictability, and time asymmetry [{\\em J. Phys. Soc. Jpn.} {\\bf 2014}, {\\em 83}, 1401]. This concept is literally a primitive chaos in such a sense that it leads to the characteristic properties of the conventional chaos under natural conditions. Then, two contrast concepts, nondegenerate Peano continuum and Cantor set, are known as the origins of the primitive chaos. In this study, the relation of these origins is investigated with the aid of a mathematical method, topology. Then, we can see the emergence of interesting concepts such as the relation of whole and part, and coarse graining, which imply the essence of our intrinsic recognition for phenomena.

  18. The origin of the parathyroid gland

    OpenAIRE

    Okabe, Masataka; Graham, Anthony

    2004-01-01

    It has long been held that the parathyroid glands and parathyroid hormone evolved with the emergence of the tetrapods, reflecting a need for new controls on calcium homeostasis in terrestrial, rather than aquatic, environments. Developmentally, the parathyroid gland is derived from the pharyngeal pouch endoderm, and studies in mice have shown that its formation is under the control of a key regulatory gene, Gcm-2. We have used a phylogenetic analysis of Gcm-2 to probe the evolutionary origins...

  19. 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.

  20. Management perspectives on country of origin

    OpenAIRE

    Rashid, A.; Barnes, L; Warnaby, G

    2016-01-01

    Purpose - The purpose of this paper is to provide a new perspective by conceptualising country of origin (COO) from a management perspective, identifying the impact different COO constructs have in the context of fashion retailer and manufacturer businesses.\\ud \\ud Design/methodology/approach – This qualitative study comprises a series of in-depth interviews with key informants from large-scale fashion retailers and manufacturers in the UK.\\ud \\ud Findings - The major findings of this researc...

  1. Feline Origin of Rotavirus Strain, Tunisia, 2008

    Science.gov (United States)

    Fredj, Mouna Ben Hadj; Heylen, Elisabeth; Zeller, Mark; Fodha, Imene; Benhamida-Rebai, Meriam; Van Ranst, Marc; Matthijnssens, Jelle

    2013-01-01

    In Tunisia in 2008, an unusual G6P[9] rotavirus, RVA/human-wt/TUN/17237/2008/G6P[9], rarely found in humans, was detected in a child. To determine the origin of this strain, we conducted phylogenetic analyses and found a unique genotype constellation resembling rotaviruses belonging to the feline BA222-like genotype constellation. The strain probably resulted from direct cat-to-human transmission. PMID:23631866

  2. Origin of Saxitoxin Biosynthetic Genes in Cyanobacteria

    OpenAIRE

    Ahmed Moustafa; Jeannette E Loram; Hackett, Jeremiah D.; Anderson, Donald M.; F Gerald Plumley; Debashish Bhattacharya

    2009-01-01

    BACKGROUND: Paralytic shellfish poisoning (PSP) is a potentially fatal syndrome associated with the consumption of shellfish that have accumulated saxitoxin (STX). STX is produced by microscopic marine dinoflagellate algae. Little is known about the origin and spread of saxitoxin genes in these under-studied eukaryotes. Fortuitously, some freshwater cyanobacteria also produce STX, providing an ideal model for studying its biosynthesis. Here we focus on saxitoxin-producing cyanobacteria and th...

  3. Origins of English and Chinese Idioms

    Institute of Scientific and Technical Information of China (English)

    张昊

    2012-01-01

    Both English and Chinese are rich in idioms. There is a similarity in theorigins of English and Chinese idioms, but on the one hand, owing to the different social background, customs, religious beliefs, geographic environment, differences are sure to appear in idioms.By comparing English and Chinese idioms from their origins, we could learn more about the relationship between idioms and culture,learning of English and the language as a whole,and have a better mastery of English.

  4. 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.

  5. Fever of Unknown Origin: An Unusual Case

    OpenAIRE

    Bansal, R. A.; Hayman, G. R.; Bansal, A. S.

    2011-01-01

    Recurrent episodic fever of unknown origin (FUO) arising from tumour of the gastrointestinal tract is rare. We report an otherwise healthy 62-year-old man with recurrent circumscribed bouts of fever and raised CRP for 3 years who has remained well and fever-free 2 years after the removal of a well-differentiated adenocarcinoma of the colon. Occult colonic neoplasm should be considered and sought when routine investigations for FUO are negative.

  6. [Fever of unknown origin. Infectious causes].

    Science.gov (United States)

    Salzberger, B; Schneidewind, A; Hanses, F; Birkenfeld, G; Müller-Schilling, M

    2012-12-01

    Infectious diseases remain one of the most important causes of fever of unexplained origin (FUO). We review the spectrum of infectious diseases in the different clinical situations of patients with FUO, namely in classical FUO, in patients with HIV infection, in health care-associated or nosocomial FUO, and in immunocompromised patients with FUO. The most important question is which clinical features make a specific disease a candidate to cause FUO.

  7. [Original contributions of Latin Americans to anesthesiology].

    Science.gov (United States)

    Aldrete, J A

    1998-10-01

    The original contributions of Latin American physicians to the science of anesthesiology are described. Many contributions have been unfairly ignored mainly because they were never published in English, but others have likewise been passed over even when published in the most prestigious journals in the field. Although many discoveries by Latin Americans have been made in the area of regional anesthesia, a considerable number of contributions have involved other aspects of anesthesia as well.

  8. Galactic origin of ultrahigh energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailov, A.A. [Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy, 31 Lenin Ave., 677980 Yakutsk (Russian Federation)

    2009-05-15

    The arrival directions of ultrahigh energy extensive air showers (EAS) by Yakutsk, AGASA, P. Auger array data are analyzed. For the first time, the maps of equal exposition of celestial sphere for the distribution of particles by AGASA and P. Auger arrays data have been constructed. The large-scale anisotropy of cosmic particles at E>4x10{sup 19} eV by Yakutsk, AGASA and P. Auger array data has been detected. The problem of cosmic particle origin is discussed.

  9. 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.

  10. Genomics and the origin of species

    OpenAIRE

    Seehausen, O.; Butlin, R K; Keller, I.; Wagner, C. E.; Boughman, J W; Hohenlohe, P. A.; Peichel, C.A.; Saetre, G.-P.; Bank, C.; Brannstrom, A.

    2013-01-01

    Speciation is a fundamental evolutionary process, the knowledge of which is crucial for understanding the origins of biodiversity. Genomic approaches are an increasingly important aspect of this research field. We review current understanding of genome-wide effects of accumulating reproductive isolation and of genomic properties that influence the process of speciation. Building on this work, we identify emergent trends and gaps in our understanding, propose new approaches to more fully integ...

  11. Original data preprocessor for Femap/Nastran

    Science.gov (United States)

    Oanta, Emil M.; Panait, Cornel; Raicu, Alexandra

    2016-12-01

    Automatic data processing and visualization in the finite elements analysis of the structural problems is a long run concern in mechanical engineering. The paper presents the `common database' concept according to which the same information may be accessed from an analytical model, as well as from a numerical one. In this way, input data expressed as comma-separated-value (CSV) files are loaded into the Femap/Nastran environment using original API codes, being automatically generated: the geometry of the model, the loads and the constraints. The original API computer codes are general, being possible to generate the input data of any model. In the next stages, the user may create the discretization of the model, set the boundary conditions and perform a given analysis. If additional accuracy is needed, the analyst may delete the previous discretizations and using the same information automatically loaded, other discretizations and analyses may be done. Moreover, if new more accurate information regarding the loads or constraints is acquired, they may be modelled and then implemented in the data generating program which creates the `common database'. This means that new more accurate models may be easily generated. Other facility consists of the opportunity to control the CSV input files, several loading scenarios being possible to be generated in Femap/Nastran. In this way, using original intelligent API instruments the analyst is focused to accurately model the phenomena and on creative aspects, the repetitive and time-consuming activities being performed by the original computer-based instruments. Using this data processing technique we apply to the best Asimov's principle `minimum change required / maximum desired response'.

  12. The puzzling origin of the genetic code.

    Science.gov (United States)

    Cedergren, R; Miramontes, P

    1996-06-01

    Recent results add to the mystery of the origin of the genetic code. In spite of early doubts, RNA can discriminate between hydrophobic amino acids under certain contexts. Moreover, codon reassignment, which has taken place in several organisms and mitochondria, is not a random process. Finally, phylogenies of some aminoacyl-tRNA synthetases suggest that the entire code was not completely assigned at the time of the divergence of bacteria from nucleated cells.

  13. Flavor origin of R-parity

    OpenAIRE

    Morisi, S.; Peinado, E.; Vicente, Avelino(IFPA, Dep. AGO, Université de Liège, Bat B5, Sart-Tilman, 4000 , Liège 1, Belgium)

    2013-01-01

    Proton stability is guaranteed in the MSSM by assuming a discrete symmetry, R-parity. However, there are additional R-parity conserving higher dimensional operators which violate lepton and baryon numbers and induce fast proton decay. Here we study the possibility that all renormalizable, as well as the most dangerous non-renormalizable, R-parity violating operators are forbidden by a flavor symmetry, providing a common origin for fermion mixing and proton and dark matter stability. We propos...

  14. Concerning the origin of handedness in humans.

    Science.gov (United States)

    Huheey, J E

    1977-01-01

    The origin of right-handedness as the predominant chirality in humans seems to be related to the tendency of human (and presumably prehuman) mothers to hold infants on the left side. The latter practice has previously been ascribed to imprinting and the soothing sound of the mother's heartbeat on the infant. Given the practice of holding the child in this manner, dextral mothers will be more skillful at manipulation of objects and selectively favored.

  15. RETROSPECTION OF INSURANCE: ORIGIN, EVOLUTION, TOPICALITY

    Directory of Open Access Journals (Sweden)

    Cristina UNGUR

    2014-03-01

    Full Text Available Any human activity implies the existence of certain dangers for life, health or property. The need to protect them has led to insurance. In this article we present the chronological evolution of the phenomenon of insurance from its origin in antiquity to the contemporary period. We also show the interdependence of development of human civilization and the diversification and development of insurance services in various historical eras.

  16. [An original contention system for hadron therapy].

    Science.gov (United States)

    Sevret, P; Magné, N; Chargari, C; Beaudré, A; Ferrand, R; Habrand, J-L

    2009-06-01

    In hadron therapy centers that have only fixed horizontal beams (i.e. most carbon ions centers and protons centers of first generation), the angulations of the beam remain technically limited, especially for the treatment of children under general anaesthesia with posterior-oblique (40 degrees or so) beams in supine position. We have been developing recently an original positioning system allowing for treatment with posterior-oblique beams, either from right or left directions, by keeping the child in the adequate position.

  17. Aesthetic and Culture Origin of Vocal Art

    Institute of Scientific and Technical Information of China (English)

    张延春

    2010-01-01

    As one of the most commonly and widely adopted art forms, vocal art has been closely related with national culture and the aesthetics trend. Traditional Chinese vocal art rooted from China' s long history and distinctive culture. On the contrary, Italian bel canto stems from the prospect of Italian Opera Art during the Renaissance period. This essay discusses the differences between East and West vocal art, from its aesthetic and culture origin.

  18. 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...... 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....

  19. [Cardioprotective effects of adaptogens of plant origin].

    Science.gov (United States)

    Maslova, L V; Lishmanov, Iu B; Maslov, L N

    1993-03-01

    The experiments performed on emotional--painful stress model in rats demonstrated cardioprotective activity of adaptogens of vegetable origin (rodiolae, eleutherococcus, levsea, p-tyrosol). Preliminary injection of rodiolae extract was found to prevent stress--induced increase in cAMP level and cGMP content decrease in heart. We can conclude that adaptogens cardioprotective effect may be the drugs to prevent stressor change in cyclic nucleotides level in myocardium.

  20. Origins of life: An operational definition

    Science.gov (United States)

    Fleischaker, Gail Raney

    1990-03-01

    Two very different models are used for the scientific study of life's origins: in the Troland-Muller model, life is molecular and its defining characteristic is gene function; in the Oparin-Haldane model, life is cellular and its defining characteristic is metabolic function. While each of these models implicitly defines the living, neither provides criteria by which theemergence of life could be recognized in the laboratory. Anoperational definition of the living makes explicit the system logic of metabolic self-production: (1) that whatever form it may take, life is a function of its biochemical processes; (2) that no single biochemical process has integrity apart from an entire network of processes; (3) that a network of processes can have continuity only by being enclosed within a boundary structure, i.e., by the selective partition of a microenvironment as a domain for the bioenergetic-biosynthetic network; and (4) that life is a single phenomenon, distinct in its continuity of capture and storage of energy in such networks, driving the processes that produce its material constituents. This paper presentsautopoiesis as life-defining and discusses the utility of its criteria in our search for the origins of life on Earth. Enactment of the autopoietic criteria would result in aminimal cell and would demonstrate the experimental recapitulation of life's Archaean origins.

  1. Topological Origins of the Slow Solar Wind

    Science.gov (United States)

    Antiochos, S.

    2008-12-01

    Although the slow solar wind has been studied for decades with both in situ and remote sensing observations, its origin is still a matter of intense debate. In the standard quasi-steady model, the slow wind is postulated to originate near coronal hole boundaries that define topologically well-behaved separatrices between open and closed field regions. In the interchange model, on the other hand, the slow wind is postulated to originate on open flux that is dynamically diffusing throughout the seemingly closed-field corona. We argue in favor of the quasi-steady scenario and propose that the slow wind is due to two effects: First, the open-closed boundary is highly complex due to the complexity of the photospheric flux distribution. Second, this boundary is continuously driven by the transport of magnetic helicity from the closed field region into the open. The implications of this model for the structure and dynamics of the corona and slow wind are discussed, and observational tests of the model are presented. This work has been supported, in part, by the NASA LWS, HTP, and SR&T programs.

  2. Planetary Systems and the Origins of Life

    Science.gov (United States)

    Pudritz, Ralph; Higgs, Paul; Stone, Jonathon

    2013-01-01

    Preface; Part I. Planetary Systems and the Origins of Life: 1. Observations of extrasolar planetary systems Shay Zucker; 2. The atmospheres of extrasolar planets L. Jeremy Richardson and Sara Seager; 3. Terrestrial planet formation Edward Thommes; 4. Protoplanetary disks, amino acids and the genetic code Paul Higgs and Ralph Pudritz; 5. Emergent phenomena in biology: the origin of cellular life David Deamer; Part II. Life on Earth: 6. Extremophiles: defining the envelope for the search for life in the Universe Lynn Rothschild; 7. Hyperthermophilic life on Earth - and on Mars? Karl Stetter; 8. Phylogenomics: how far back in the past can we go? Henner Brinkmann, Denis Baurain and Hervé Philippe; 9. Horizontal gene transfer, gene histories and the root of the tree of life Olga Zhaxybayeva and J. Peter Gogarten; 10. Evolutionary innovation versus ecological incumbency Adolf Seilacher; 11. Gradual origins for the Metazoans Alexandra Pontefract and Jonathan Stone; Part III. Life in the Solar System?: 12. The search for life on Mars Chris McKay; 13. Life in the dark dune spots of Mars: a testable hypothesis Eörs Szathmary, Tibor Ganti, Tamas Pocs, Andras Horvath, Akos Kereszturi, Szaniszlo Berzci and Andras Sik; 14. Titan: a new astrobiological vision from the Cassini-Huygens data François Raulin; 15. Europa, the Ocean Moon: tides, permeable ice, and life Richard Greenberg; Index.

  3. [The origin of homoiothermy--unsolved problem].

    Science.gov (United States)

    Dol'nik, V P

    2003-01-01

    The analysis of allometric dependence of energy expenditure on body mass among reptiles, birds and mammals has shown that standard metabolic rate of reptiles when they are warmed up to the temperature of homoiothermic animals is an order of magnitude lower than that of birds and mammals. Basal metabolism is originated as special feature historically related to the metabolism during active behavior, rather than thermal regulation. Facultative endothermy was not advantageous for large animals because of long time needed to warm up the body. The ancestors of birds and animals escaped negative consequences of van't-Hoff equation by choosing constant body temperature. Heat conductivity of reptile's covers is so great, that it cannot keep endogenous warm of resting animal at any temperature of the body. Reptile "dressed" in covers of bird or mammal would be able to keep warm under conditions of maximal aerobic muscular activity and body temperature similar to that of homoiothermic animals. The base of chemical thermoregulation in birds and mammals is a thermoregulatory muscle tonus which remains unknown. One can suppose that during evolution of birds and mammals the saltation-liked origin of endothermy "fixed" the level of metabolism typical for running reptile and transformed in into the basal metabolism. This event took place at the cell and tissue level. The absence of palaeontological evidences and intermediate forms among recent species does not allow easy understanding of homoiothermy origin.

  4. Fever of unknown origin (FUO) revised.

    Science.gov (United States)

    Unger, Manuel; Karanikas, Georgios; Kerschbaumer, Andreas; Winkler, Stefan; Aletaha, Daniel

    2016-11-01

    Fever of unknown origin (FUO) was originally characterised in 1961 by Petersdorf and Beeson as a disease condition of temperature exceeding 38.3 °C on at least three occasions over a period of at least three weeks, with no diagnosis made despite one week of inpatient investigation. However, since underlying diseases are often reported for classical FUO, these presentations may not be considered to be of "unknown origin". Rather, the aetiology of prolonged fever may resolve, or not resolve. The definition of fever with unresolved cause (true FUO) is difficult, as it is a moving target, given the constant advancement of imaging and biomarker analysis. Therefore, the prevalence of fever with unresolved cause (FUO) is unknown.In this review, we report such a case of prolonged fever, which initially has presented as classical FUO, and discuss current literature. Furthermore, we will give an outlook, how a prospective study on FUO will allow to solve outstanding issues like the utility of different diagnostic investigations, and the types and prevalence of various underlying diseases.

  5. 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.

  6. West Florida shelf upwelling: Origins and pathways

    Science.gov (United States)

    Weisberg, Robert H.; Zheng, Lianyuan; Liu, Yonggang

    2016-08-01

    Often described as oligotrophic, the west Florida continental shelf supports abundant fisheries, experiences blooms of the harmful alga, Karenia brevis, and exhibits subsurface chlorophyll maxima evident in shipboard and glider surveys. Renewal of inorganic nutrients by the upwelling of deeper ocean water onto the shelf may account for this, but what are the origins and pathways by which such new water may broach the shelf break and advance toward the shoreline? We address these questions via numerical model simulations of pseudo-Lagrangian, isopycnic water parcel trajectories. Focus is on 2010, when the west Florida shelf was subjected to an anomalously protracted period of upwelling caused by Gulf of Mexico Loop Current interactions with the shelf slope. Origins and pathways are determined by integrating trajectories over successive 45 day intervals, beginning from different locations along the shelf break and at various locations and depths along the shelf slope. Waters upwelling across the shelf break are found to originate from relatively shallow depths along the shelf slope. Even for the anomalous 2010 year, much of this upwelling occurs from about 150 m and above, although waters may broach the shelf break from 300 m depth, particularly in the Florida Panhandle. Such interannual renewal of west Florida shelf waters appears to have profound effects on west Florida shelf ecology.

  7. Origin of Hawking radiation: firewall or atmosphere?

    Science.gov (United States)

    Kim, Wontae

    2017-02-01

    The Unruh vacuum not admitting any outgoing flux at the horizon implies that the origin of the outgoing Hawking radiation is the atmosphere of a near-horizon quantum region without resort to the firewall; however, the existence of the firewall of superplanckian excitations at the horizon can be supported by the infinite Tolman temperature at the horizon. In an exactly soluble model, we explicitly show that the firewall necessarily emerges out of the Unruh vacuum so that the Tolman temperature in the Unruh vacuum is divergent in essence due to the infinitely blueshifted negative ingoing flux crossing the horizon rather than the outgoing flux. We also show that the outgoing Hawking radiation in the Unruh vacuum indeed originates from the atmosphere, not just at the horizon, which is of no relevance to the infinite blueshift. Consequently, the firewall from the infinite Tolman temperature and the Hawking radiation from the atmosphere turn out to be compatible, once we waive the claim that the Hawking radiation in the Unruh vacuum originates from the infinitely blueshifted outgoing excitations at the horizon.

  8. 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.

  9. 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.

  10. On the origin of Earth's Moon

    Science.gov (United States)

    Barr, Amy C.

    2016-09-01

    The Giant Impact is currently accepted as the leading theory for the formation of Earth's Moon. Successful scenarios for lunar origin should be able to explain the chemical composition of the Moon (volatile content and stable isotope ratios), the Moon's initial thermal state, and the system's bulk physical and dynamical properties. Hydrocode simulations of the impact have long been able to match the bulk properties, but recent, more detailed work on the evolution of the protolunar disk has yielded great insight into the origin of the Moon's chemistry and its early thermal history. Here I show that the community has constructed the elements of an end-to-end theory for lunar origin that matches the overwhelming majority of observational constraints. In spite of the great progress made in recent years, new samples of the Moon, clarification of processes in the impact-generated disk, and a broader exploration of impact parameter space could yield even more insights into this fundamental and uniquely challenging geophysical problem.

  11. On the Origin of Earth's Moon

    CERN Document Server

    Barr, Amy C

    2016-01-01

    The Giant Impact is currently accepted as the leading theory for the formation of Earth's Moon. Successful scenarios for lunar origin should be able to explain the chemical composition of the Moon (volatile content and stable isotope ratios), the Moon's initial thermal state, and the system's bulk physical and dynamical properties. Hydrocode simulations of the formation of the Moon have long been able to match the bulk properties, but recent, more detailed work on the evolution of the protolunar disk has yielded great insight into the origin of the Moon's chemistry, and its early thermal history. Here, I show that the community has constructed the elements of an end-to-end theory for lunar origin that matches the overwhelming majority of observational constraints. In spite of the great progress made in recent years, new samples of the Moon, clarification of processes in the impact-generated disk, and a broader exploration of impact parameter space could yield even more insights into this fundamental and uniqu...

  12. 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.

  13. Origins Space Telescope: Solar System Science

    Science.gov (United States)

    Wright, Edward L.; Origins Space Telescope Study Team

    2017-01-01

    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.In the Solar System, OST will provide km/sec resolution on lines from planet, moons and comets. OST will measure molecular abundances and isotope ratios in planets and comets. OST will be able to do continuum surveys for faint moving sources such as Kuiper Belt Objects, enabling a census of smaller objects in the Kuiper Belt. If the putative Planet IX is massive enough to be self-luminous, then OST will be able to detect it out to thousands of AU from the Sun.

  14. Proton gradients at the origin of life.

    Science.gov (United States)

    Lane, Nick

    2017-06-01

    Chemiosmotic coupling - the harnessing of electrochemical ion gradients across membranes to drive metabolism - is as universally conserved as the genetic code. As argued previously in these pages, such deep conservation suggests that ion gradients arose early in evolution, and might have played a role in the origin of life. Alkaline hydrothermal vents harbour pH gradients of similar polarity and magnitude to those employed by modern cells, one of many properties that make them attractive models for life's origin. Their congruence with the physiology of anaerobic autotrophs that use the acetyl CoA pathway to fix CO2 gives the alkaline vent model broad appeal to biologists. Recently, however, a paper by Baz Jackson criticized the hypothesis, concluding that natural pH gradients were unlikely to have played any role in the origin of life. Unfortunately, Jackson mainly criticized his own interpretations of the theory, not what the literature says. This counterpoint is intended to set the record straight. © 2017 WILEY Periodicals, Inc.

  15. A Strategy for Origins of Life Research.

    Science.gov (United States)

    Scharf, Caleb; Virgo, Nathaniel; Cleaves, H James; Aono, Masashi; Aubert-Kato, Nathanael; Aydinoglu, Arsev; Barahona, Ana; Barge, Laura M; Benner, Steven A; Biehl, Martin; Brasser, Ramon; Butch, Christopher J; Chandru, Kuhan; Cronin, Leroy; Danielache, Sebastian; Fischer, Jakob; Hernlund, John; Hut, Piet; Ikegami, Takashi; Kimura, Jun; Kobayashi, Kensei; Mariscal, Carlos; McGlynn, Shawn; Menard, Brice; Packard, Norman; Pascal, Robert; Pereto, Juli; Rajamani, Sudha; Sinapayen, Lana; Smith, Eric; Switzer, Christopher; Takai, Ken; Tian, Feng; Ueno, Yuichiro; Voytek, Mary; Witkowski, Olaf; Yabuta, Hikaru

    2015-12-01

    Contents 1. Introduction 1.1. A workshop and this document 1.2. Framing origins of life science 1.2.1. What do we mean by the origins of life (OoL)? 1.2.2. Defining life 1.2.3. How should we characterize approaches to OoL science? 1.2.4. One path to life or many? 2. A Strategy for Origins of Life Research 2.1. Outcomes-key questions and investigations 2.1.1. Domain 1: Theory 2.1.2. Domain 2: Practice 2.1.3. Domain 3: Process 2.1.4. Domain 4: Future studies 2.2. EON Roadmap 2.3. Relationship to NASA Astrobiology Roadmap and Strategy documents and the European AstRoMap   Appendix I   Appendix II   Supplementary Materials  References.

  16. Computational studies of origins of life scenarios

    Science.gov (United States)

    Mathew, Damien Cherian

    Understanding the origins of life on Earth is one of the most intriguing problems facing science today. In the research presented here, we apply computational methods to explore origins of life scenarios. In particular, we focus on the origins of the genetic code and the intersection between geochemistry and a primordial "biochemistry" in which mononucleotides could form short oligoucleotide chains. We also apply quantum chemical methods to a modern biochemical reaction, the charging of tRNA by an aminoacyl-tRNA synthetase, in order to shed light on the possible chemistry one may want to consider in problems relating to the origins of life. The question of how codons came to be associated with specific amino acids in the present form of the genetic code is one fundamental part of gaining insight into the origins of life. Carl Woese and coworkers designed a series of experiments to test associations between amino acids and nucleobases that may have played a role in establishing the genetic code. Through these experiments it was found that a property of amino acids called the polar requirement (PR) is correlated to the organization of the codon table. No other property of amino acids has been found that correlates with the codon table as well as PR, indicating that PR is uniquely related to the modern genetic code. Using molecular dynamics simulations of amino acids in solutions of water and dimethylpyridine used to experimentally measure PR, we show that variations in the partitioning between the two phases as described by radial distribution functions correlate well with the measured PRs. Partition coefficients based on probability densities of the amino acids in each phase have the linear behavior with base concentration as suggested by the PR experiments. We also investigate the possible roles of inorganic mineral surfaces in catalysis and stabilization of reactions essential for early forms of replicating systems that could have evolved into biochemical

  17. adidas Originals by Originals Jeremy Scott美式粗犷潮流

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    在所有adidas Originals 60 Years of Sole&Stripes限定系列中,Originals By Originals无疑是最受关注的.这个囊括了全世界多位知名设计师的联名别注系列的规模是近年来Adidas Originals所有周年别注中最庞大的。

  18. Examining life's origins : history and epistemic principles in the search for the origins of life

    OpenAIRE

    Martin, Eric Collin

    2010-01-01

    My dissertation provides a novel philosophical and historical analysis of origins of life research, a scientific field that poses significant conceptual challenges to evolutionary theory, standard experimental methodology, and theory integration across disciplines. The origin of life is sometimes considered "the most fundamental problem in biology." Despite its theoretical significance, the field of study is fraught with fundamental disagreements over theories, methods and approaches. The ori...

  19. 19 CFR 102.23 - Origin and Manufacturer Identification

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Origin and Manufacturer Identification 102.23...; DEPARTMENT OF THE TREASURY RULES OF ORIGIN Rules of Origin § 102.23 Origin and Manufacturer Identification (a) Textile or Apparel Product Manufacturer Identification. All entries of textile or apparel products...

  20. 19 CFR 134.11 - Country of origin marking required.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Country of origin marking required. 134.11 Section... OF THE TREASURY COUNTRY OF ORIGIN MARKING Articles Subject to Marking § 134.11 Country of origin... English name of the country of origin of the article, at the time of importation into the...

  1. 19 CFR 10.234 - Certificate of Origin.

    Science.gov (United States)

    2010-04-01

    ... Origin must be prepared by the exporter in the CBTPA beneficiary country. Where the CBTPA beneficiary... 19 Customs Duties 1 2010-04-01 2010-04-01 false Certificate of Origin. 10.234 Section 10.234... Certificate of Origin. A Certificate of Origin as specified in § 10.236 must be employed to certify that...

  2. Genotoxic Klebsiella pneumoniae in Taiwan.

    Directory of Open Access Journals (Sweden)

    Yi-Chyi Lai

    Full Text Available BACKGROUND: Colibactin is a nonribosomal peptide-polyketide synthesized by multi-enzyme complexes encoded by the pks gene cluster. Colibactin-producing Escherichia coli have been demonstrated to induce host DNA damage and promote colorectal cancer (CRC development. In Taiwan, the occurrence of pyogenic liver abscess (PLA has been suggested to correlate with an increasing risk of CRC, and Klebsiella pneumoniae is the predominant PLA pathogen in Taiwan. METHODOLOGY/PRINCIPAL FINDINGS: At the asn tRNA loci of the newly sequenced K. pneumoniae 1084 genome, we identified a 208-kb genomic island, KPHPI208, of which a module identical to the E. coli pks colibactin gene cluster was recognized. KPHPI208 consists of eight modules, including the colibactin module and the modules predicted to be involved in integration, conjugation, yersiniabactin production, microcin production, and unknown functions. Transient infection of BALB/c normal liver cells with K. pneumoniae 1084 increased the phosphorylation of histone H2AX, indicating the induction of host DNA damage. Colibactin was required for the genotoxicity of K. pneumoniae 1084, as it was diminished by deletion of clbA gene and restored to the wild type level by trans-complementation with a clbA coding plasmid. Besides, BALB/c mice infected with K. pneumoniae 1084 exhibited enhanced DNA damage in the liver parenchymal cells when compared to the isogenic clbA deletion mutant. By PCR detection, the prevalence of pks-positive K. pneumoniae in Taiwan is 25.6%, which is higher than that reported in Europe (3.5%, and is significantly correlated with K1 type, which predominantly accounted for PLA in Taiwan. CONCLUSIONS: Our knowledge regarding how bacteria contribute to carcinogenesis has just begun. The identification of genotoxic K. pneumoniae and its genetic components will facilitate future studies to elucidate the molecular basis underlying the link between K. pneumoniae, PLA, and CRC.

  3. Activating and Attenuating the Amicoumacin Antibiotics

    Directory of Open Access Journals (Sweden)

    Hyun Bong Park

    2016-06-01

    Full Text Available The amicoumacins belong to a class of dihydroisocoumarin natural products and display antibacterial, antifungal, anticancer, and anti-inflammatory activities. Amicoumacins are the pro-drug activation products of a bacterial nonribosomal peptide-polyketide hybrid biosynthetic pathway and have been isolated from Gram-positive Bacillus and Nocardia species. Here, we report the stimulation of a “cryptic” amicoumacin pathway in the entomopathogenic Gram-negative bacterium Xenorhabdus bovienii, a strain not previously known to produce amicoumacins. X. bovienii participates in a multi-lateral symbiosis where it is pathogenic to insects and mutualistic to its Steinernema nematode host. Waxmoth larvae are common prey of the X. bovienii-Steinernema pair. Employing a medium designed to mimic the amino acid content of the waxmoth circulatory fluid led to the detection and characterization of amicoumacins in X. bovienii. The chemical structures of the amicoumacins were supported by 2D-NMR, HR-ESI-QTOF-MS, tandem MS, and polarimeter spectral data. A comparative gene cluster analysis of the identified X. bovienii amicoumacin pathway to that of the Bacillus subtilis amicoumacin pathway and the structurally-related Xenorhabdus nematophila xenocoumacin pathway is presented. The X. bovienii pathway encodes an acetyltransferase not found in the other reported pathways, which leads to a series of N-acetyl-amicoumacins that lack antibacterial activity. N-acetylation of amicoumacin was validated through in vitro protein biochemical studies, and the impact of N-acylation on amicoumacin’s mode of action was examined through ribosomal structural analyses.

  4. Origin of saxitoxin biosynthetic genes in cyanobacteria.

    Directory of Open Access Journals (Sweden)

    Ahmed Moustafa

    Full Text Available BACKGROUND: Paralytic shellfish poisoning (PSP is a potentially fatal syndrome associated with the consumption of shellfish that have accumulated saxitoxin (STX. STX is produced by microscopic marine dinoflagellate algae. Little is known about the origin and spread of saxitoxin genes in these under-studied eukaryotes. Fortuitously, some freshwater cyanobacteria also produce STX, providing an ideal model for studying its biosynthesis. Here we focus on saxitoxin-producing cyanobacteria and their non-toxic sisters to elucidate the origin of genes involved in the putative STX biosynthetic pathway. METHODOLOGY/PRINCIPAL FINDINGS: We generated a draft genome assembly of the saxitoxin-producing (STX+ cyanobacterium Anabaena circinalis ACBU02 and searched for 26 candidate saxitoxin-genes (named sxtA to sxtZ that were recently identified in the toxic strain Cylindrospermopsis raciborskii T3. We also generated a draft assembly of the non-toxic (STX- sister Anabaena circinalis ACFR02 to aid the identification of saxitoxin-specific genes. Comparative phylogenomic analyses revealed that nine putative STX genes were horizontally transferred from non-cyanobacterial sources, whereas one key gene (sxtA originated in STX+ cyanobacteria via two independent horizontal transfers followed by fusion. In total, of the 26 candidate saxitoxin-genes, 13 are of cyanobacterial provenance and are monophyletic among the STX+ taxa, four are shared amongst STX+ and STX-cyanobacteria, and the remaining nine genes are specific to STX+ cyanobacteria. CONCLUSIONS/SIGNIFICANCE: Our results provide evidence that the assembly of STX genes in ACBU02 involved multiple HGT events from different sources followed presumably by coordination of the expression of foreign and native genes in the common ancestor of STX+ cyanobacteria. The ability to produce saxitoxin was subsequently lost multiple independent times resulting in a nested relationship of STX+ and STX- strains among Anabaena

  5. A paleontological perspective of vertebrate origin

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The Early Cambrian Haikouichthys and Haikouella have been claimed to be related to contribute in an important way to our understanding of vertebrate origin, but there have been heated debates about how exactly they are to be interpreted. New discoveries of numerous specimens of Haikouichthys not only confirm the identity of previously described structures such as the dorsal and the ventral fins, and chevron-shaped myomeres, but also reveal many new important characteristics, including sensory organs of the head (e.g. large eyes), and a prominent notochord with differentiated vertebral elements. This "first fish" appears, however, to retain primitive reproductive features of acraniates, suggesting that it is a stem-group craniates. A new order (Myllokunmingiida) and a new family (Myllokunmingiidae) are erected, and a new species, Zhongjianichthys rostratus (gen. et sp. nov.), is described herein. Over 1400 newly-discovered specimens of Haikouella provide a wealth of anatomical information on this organism. It differs from chordates in many organs and organ systems, including the skin, muscles, respiratory, circulatory and nervous systems. In contrast, its body-design resembles that of vetulicolians, and the presence of a "transitional" nervous system with both dorsal and ventral nerve cords suggests an affinity with living hemichordates. On the basis of these and other recent findings of fossil deuterostomes, a five-step hypothesis for vertebrate origin is proposed, intended to bridge the long- standing gap between protostomes and vertebrates. Four of the five steps accord with established ideas current in modern evolutionary zoology. Evidence for the first step is obtainable only from fossils, and specifically from fossils found from South China, hence the crucial importance of S. China sites for our understanding of early vertebrate origins and evolution. Accordingly, South China is suggested as the oldest-known birthplace of the whole vertebrates.

  6. Reconsidering the origins of Forsbergh birefringence patterns

    Science.gov (United States)

    Schilling, A.; Kumar, A.; McQuaid, R. G. P.; Glazer, A. M.; Thomas, P. A.; Gregg, J. M.

    2016-07-01

    In 1949, Forsbergh, Jr. reported spontaneous spatial ordering in the birefringence patterns seen in flux-grown BaTi O3 crystals under the transmission polarized light microscope [Phys. Rev. 76, 1187 (1949), 10.1103/PhysRev.76.1187]. Stunningly regular square-net arrays were often only found within a finite temperature window and could be induced on both heating and cooling, suggesting genuine thermodynamic stability. At the time, Forsbergh rationalized the patterns to have resulted from the impingement of ferroelastic domains, creating a complex tessellation of variously shaped domain packets. However, no direct evidence for the intricate microstructural arrangement proposed by Forsbergh has subsequently been found. Moreover, there are no robust thermodynamic arguments to explain the finite region of thermal stability, its occurrence just below the Curie temperature, and the apparent increase in entropy associated with the loss of the Forsbergh pattern on cooling. Despite decades of research on ferroelectrics, this ordering phenomenon and its thermodynamic origin have hence remained a mystery. In this paper, we reexamine the microstructure of flux-grown BaTi O3 crystals, which show Forsbergh birefringence patterns. Given an absence of any obvious arrays of domain polyhedra or even regular shapes of domain packets, we suggest an alternative origin for the Forsbergh pattern in which sheets of orthogonally oriented ferroelastic stripe domains simply overlay one another. We show explicitly that the Forsbergh birefringence pattern occurs if the periodicity of the stripe domains is above a critical value. Moreover, by considering well-established semiempirical models, we show that the significant domain coarsening needed to generate the Forsbergh birefringence is fully expected in a finite window below the Curie temperature. We hence present a much more straightforward rationalization of the Forsbergh pattern than that originally proposed in which exotic thermodynamic

  7. Origins Space Telescope: Cosmology and Reionization

    Science.gov (United States)

    Vieira, Joaquin D.; Origins Space Telescope Study Team

    2017-01-01

    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.

  8. Chance of Necessity: Modeling Origins of Life

    Science.gov (United States)

    Pohorille, Andrew

    2006-01-01

    The fundamental nature of processes that led to the emergence of life has been a subject of long-standing debate. One view holds that the origin of life is an event governed by chance, and the result of so many random events is unpredictable. This view was eloquently expressed by Jacques Monod in his book Chance or Necessity. In an alternative view, the origin of life is considered a deterministic event. Its details need not be deterministic in every respect, but the overall behavior is predictable. A corollary to the deterministic view is that the emergence of life must have been determined primarily by universal chemistry and biochemistry rather than by subtle details of environmental conditions. In my lecture I will explore two different paradigms for the emergence of life and discuss their implications for predictability and universality of life-forming processes. The dominant approach is that the origin of life was guided by information stored in nucleic acids (the RNA World hypothesis). In this view, selection of improved combinations of nucleic acids obtained through random mutations drove evolution of biological systems from their conception. An alternative hypothesis states that the formation of protocellular metabolism was driven by non-genomic processes. Even though these processes were highly stochastic the outcome was largely deterministic, strongly constrained by laws of chemistry. I will argue that self-replication of macromolecules was not required at the early stages of evolution; the reproduction of cellular functions alone was sufficient for self-maintenance of protocells. In fact, the precise transfer of information between successive generations of the earliest protocells was unnecessary and could have impeded the discovery of cellular metabolism. I will also show that such concepts as speciation and fitness to the environment, developed in the context of genomic evolution also hold in the absence of a genome.

  9. Origens da vida Origins of life

    Directory of Open Access Journals (Sweden)

    Augusto Damineli

    2007-04-01

    Full Text Available Apresentamos um panorama geral das idéias sobre a origem da vida na história. Após delinearmos os principais temas necessários para o entendimento da origem da vida, mostramos as características básicas da vida atual e as relações entre os seres vivos que sugerem um ancestral comum. Revemos as condições químicas pré-bióticas no ambiente terrestre e fora dele. Quanto ao aparecimento da vida, confrontamos as principais vertentes sobre a precedência do código genético ou do metabolismo. Evidenciamos a curta janela de tempo para o estabelecimento da vida na Terra, indicando a facilidade de esse processo ocorrer no Universo. Finalmente, são apresentados os fundamentos dos projetos atuais de procura de vida fora de nosso planeta.We present a historical perspective about the ideas concerning the origin of life. After displaying the main topics necessary for understanding life’s origin, the main characteristics of the present life forms and their relationships are shown, suggesting a common ancestor. The conditions for prebiotic chemistry in terrestrial or interplanetary environments are reviewed. We put in context the arguments about the early origin of replicators versus metabolism. The very narrow window for life settlement in the early Earth is stressed, pointing to the likelihood of life arising in other places in the Universe. Finally, we present the cornerstones of current search for life outside our planet.

  10. Developmental origins of inflammatory and immune diseases.

    Science.gov (United States)

    Chen, Ting; Liu, Han-Xiao; Yan, Hui-Yi; Wu, Dong-Mei; Ping, Jie

    2016-08-01

    Epidemiological and experimental animal studies show that suboptimal environments in fetal and neonatal life exert a profound influence on physiological function and risk of diseases in adult life. The concepts of the 'developmental programming' and Developmental Origins of Health and Diseases (DOHaD) have become well accepted and have been applied across almost all fields of medicine. Adverse intrauterine environments may have programming effects on the crucial functions of the immune system during critical periods of fetal development, which can permanently alter the immune function of offspring. Immune dysfunction may in turn lead offspring to be susceptible to inflammatory and immune diseases in adulthood. These facts suggest that inflammatory and immune disorders might have developmental origins. In recent years, inflammatory and immune disorders have become a growing health problem worldwide. However, there is no systematic report in the literature on the developmental origins of inflammatory and immune diseases and the potential mechanisms involved. Here, we review the impacts of adverse intrauterine environments on the immune function in offspring. This review shows the results from human and different animal species and highlights the underlying mechanisms, including damaged development of cells in the thymus, helper T cell 1/helper T cell 2 balance disturbance, abnormal epigenetic modification, effects of maternal glucocorticoid overexposure on fetal lymphocytes and effects of the fetal hypothalamic-pituitary-adrenal axis on the immune system. Although the phenomena have already been clearly implicated in epidemiologic and experimental studies, new studies investigating the mechanisms of these effects may provide new avenues for exploiting these pathways for disease prevention.

  11. Fever of unknown origin in elderly patients

    Directory of Open Access Journals (Sweden)

    Turkulov Vesna

    2011-01-01

    Full Text Available Introduction. Causes of fever of unknown origin are different. It is considered that it can be caused with over 200 different clinical entities. Aetiological causes differ according to different categories of age. Febricity in the elderly is at most the result of autoimmune processes, malignancies, bacterial infections and vasculitis. Objective. The aim of this study was to determine the most common characteristics of fever, the most common laboratory, bacterial and viral tests and to analyze applied therapy in patients with unknown febrile state, and to affirm final diagnosis in elderly patients, as well as younger than 65 years old, and to define outcome of disease in both groups of patients. Methods. Research comprised 100 patients who had been treated at the Infectious Disease Clinic of the Clinical Centre of Vojvodina in Novi Sad, during a three-year period, and in whom fever of unknown origin had been diagnosed. Patients were divided into two homogenous groups of 50 people. The first one (S consisted of patients older than 65 years, and the second, control group (K was constituted of patients younger than the age of 65. All of them were chosen by random sample method. Results. Average results of standard laboratory parameters of infection were obtained, such as erythrocyte sedimentation rate (ESR, fibrinogen, CRP, and especially leukocyte, and those were significantly higher in the group of elderly patients. The cause had not been found in 10% of elderly patient group, and in the younger group, not even in the third of patients. Among known causative agents dominant were infections, usually of respiratory and urinary tract, in both tested groups. Even 28% of the elderly had sepsis, and 10% endocarditis. Malignant diseases were more frequent in group of the elderly patients, and immune i.e. systematic disorders were evenly noticed in both groups of patients. Conclusion. Despite advanced studies in medicine, and existence of modern

  12. The origins of phagocytosis and eukaryogenesis.

    Science.gov (United States)

    Yutin, Natalya; Wolf, Maxim Y; Wolf, Yuri I; Koonin, Eugene V

    2009-02-26

    Phagocytosis, that is, engulfment of large particles by eukaryotic cells, is found in diverse organisms and is often thought to be central to the very origin of the eukaryotic cell, in particular, for the acquisition of bacterial endosymbionts including the ancestor of the mitochondrion. Comparisons of the sets of proteins implicated in phagocytosis in different eukaryotes reveal extreme diversity, with very few highly conserved components that typically do not possess readily identifiable prokaryotic homologs. Nevertheless, phylogenetic analysis of those proteins for which such homologs do exist yields clues to the possible origin of phagocytosis. The central finding is that a subset of archaea encode actins that are not only monophyletic with eukaryotic actins but also share unique structural features with actin-related proteins (Arp) 2 and 3. All phagocytic processes are strictly dependent on remodeling of the actin cytoskeleton and the formation of branched filaments for which Arp2/3 are responsible. The presence of common structural features in Arp2/3 and the archaeal actins suggests that the common ancestors of the archaeal and eukaryotic actins were capable of forming branched filaments, like modern Arp2/3. The Rho family GTPases that are ubiquitous regulators of phagocytosis in eukaryotes appear to be of bacterial origin, so assuming that the host of the mitochondrial endosymbiont was an archaeon, the genes for these GTPases come via horizontal gene transfer from the endosymbiont or in an earlier event. The present findings suggest a hypothetical scenario of eukaryogenesis under which the archaeal ancestor of eukaryotes had no cell wall (like modern Thermoplasma) but had an actin-based cytoskeleton including branched actin filaments that allowed this organism to produce actin-supported membrane protrusions. These protrusions would facilitate accidental, occasional engulfment of bacteria, one of which eventually became the mitochondrion. The acquisition of

  13. Origins of the current seventh cholera pandemic.

    Science.gov (United States)

    Hu, Dalong; Liu, Bin; Feng, Lu; Ding, Peng; Guo, Xi; Wang, Min; Cao, Boyang; Reeves, Peter R; Wang, Lei

    2016-11-29

    Vibrio cholerae has caused seven cholera pandemics since 1817, imposing terror on much of the world, but bacterial strains are currently only available for the sixth and seventh pandemics. The El Tor biotype seventh pandemic began in 1961 in Indonesia, but did not originate directly from the classical biotype sixth-pandemic strain. Previous studies focused mainly on the spread of the seventh pandemic after 1970. Here, we analyze in unprecedented detail the origin, evolution, and transition to pandemicity of the seventh-pandemic strain. We used high-resolution comparative genomic analysis of strains collected from 1930 to 1964, covering the evolution from the first available El Tor biotype strain to the start of the seventh pandemic. We define six stages leading to the pandemic strain and reveal all key events. The seventh pandemic originated from a nonpathogenic strain in the Middle East, first observed in 1897. It subsequently underwent explosive diversification, including the spawning of the pandemic lineage. This rapid diversification suggests that, when first observed, the strain had only recently arrived in the Middle East, possibly from the Asian homeland of cholera. The lineage migrated to Makassar, Indonesia, where it gained the important virulence-associated elements Vibrio seventh pandemic island I (VSP-I), VSP-II, and El Tor type cholera toxin prophage by 1954, and it then became pandemic in 1961 after only 12 additional mutations. Our data indicate that specific niches in the Middle East and Makassar were important in generating the pandemic strain by providing gene sources and the driving forces for genetic events.

  14. Management of unknown origin cerebral metastases

    Directory of Open Access Journals (Sweden)

    F.M. Gramada

    2011-03-01

    Full Text Available Aim: The present study attempts todetermine the steps for obtaining theetiological diagnosis of brain metastaseswith unknown origin.Material and methods: A total of 190patients with brain metastases diagnosed inthe Department of Neurosurgery inEmergency Hospital ”N. Oblu” Iasibetween 2007-2010 were included in thisstudy. The clinical characteristics andpathological features were analyzed.Results: There were 102 males and 88females with a M:F ratio of 1.15:1. Themedian age of patients was 47.07 years(range 31-77 years. Females patients wereolder (mean age 57.21 years than malespatients (49.15 years. 154 patients (81.05%had single brain metastasis, and 36 patients(18.95% had more than two. The lesionswere supratentorial in 142 patients(74.73%, infratentorial in 18 (9.47%, andboth infratentorial and supratentorial in 30patients (15.78%. Surgical treatmentinvolved complete resection in 47.9% ofcases, subtotal resection in 26.8%, andbiopsy alone in the remainder (25.3%.Brain metastases originating in lung cancerrepresented the most common type(47.39%, followed by those from breastcancer (19.79%, then those from skin(melanoma (8.33%, genitourinarycarcinoma (6.30%, and gastrointestinalcarcinoma (2.62%. In 16.31% of cases, theprimary tumor remained unknown, despiteextensive investigation.Conclusion: The primary cancer leadingto brain metastases can be detected eitherby obtaining a sample of tumoral tissuethrough a neurosurgical operation on theintracerebral tumor (total ablation orstereotactic biopsy with histopathologicalexamination, or by additional tests of thewhole body. Taken into consideration theresults of our own study, the managementof the patients with brain metastases shouldinclude a thoracic CT scan oranteroposterior and lateral chest X-ray,clinical breast examination andmammography, abdominal ultrasoundexploration, and skin, kidney and prostateexamination. With the most sophisticatedmethods of diagnosis in approximately 16%of cases the

  15. [Differential diagnosis in fever of unknown origin].

    Science.gov (United States)

    Huppertz, H-I

    2006-11-01

    Fever is one of the most frequent and important symptoms in pediatrics. Most cases are caused by self-limiting viral or easily treatable bacterial infections. If after 5-7 days no cause of the ongoing fever has been found, the condition is termed fever of unknown origin, a working diagnosis which often poses a diagnostic challenge. The ultimate cause may be an infectious disease, a chronic inflammatory disorder, a malignancy, or another rare disease. The cause may also remain obscure or the fever can finally disappear. Here we elaborate the diagnostic work-up and symptomatic treatment.

  16. Ubud: From The Origins to 19201

    Directory of Open Access Journals (Sweden)

    Jean Couteau

    2015-10-01

    Full Text Available AbstractToday’s historis often tries to weave together unquestionablefacts with a narrative that consciously gives room to pastmyths and legends. The following article about the famous“cultural” resort of Ubud freely applies this approach to history.Myths and legends about the origin of Ubud combine withunquestionable historical facts to convey, beyond the Ubud’sraw history proper, the prevailing athmosphere of Ubud’spre-modern past. Thus the mythical seer Resi Merkandayais made to appear alongside the story of the kembar buncing(fraternal, non-identical twins of the House of Ubud, and thehistory of Western presence and intervention.

  17. [Internal carotid aneurysm of dysphasic origin].

    Science.gov (United States)

    Ouldsalek, E; El Idrissi, R; Elfatemi, B; Zahdi, O; El Khaloufi, S; Lekehal, B; Sefiani, Y; El Mesnaoui, A; Bensaid, Y

    2014-12-01

    Extracranial carotid aneurysms are rare, but are of significant clinical interest due to the high risk of cerebral embolism. Despite considerable progress in endovascular techniques, surgical treatment of these aneurysms remains the golden standard. We report the case of a 50-year-old man who presented an aneurysm of the left internal carotid artery measuring 46 × 26 mm. Resection of the aneurysm with interposition of a prosthetic graft was performed. The postoperative course was uneventful. Pathology reported that the aneurysmal sac probably had a dysplastic origin. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  18. Counterpoint in Explanation of Originative Apprehension

    Directory of Open Access Journals (Sweden)

    Michael Ewbank

    2016-09-01

    Full Text Available Originative apprehension often has been examined in recent decades in light of Aquinas’ reflections. Yet there has not always been agreement in regard to what constitutes such, often due to different emphases given by interpreters to aspects of St. Thomas’ analyses articulated in different contexts. Arguably, it is possible to reconcile certain seemingly divergent important interpretations by reflecting on an important, yet somewhat recessive, theme that Thomas adverted to sparingly throughout his career in utilizing analyses of predecessors to forge his own synthesis to explain cognition in terms of being that is centered on the reciprocal priorities of judging and concomitant incomplex abstracting.

  19. 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.

  20. Origin of moisture at Arctic sites

    OpenAIRE

    Jonassen, Trine

    2016-01-01

    The hydrological cycle is an important component in the understanding of the climate system, and a good understanding of the moisture transport in the atmosphere is important in a changing climate. The climate change may have large impact on the Arctic sites. In this thesis we look at the moisture source for NEEM (North Greenland Eemian Drilling Project) in Greenland (77.45°N, 51.05°W, 2484m a.s.l.) and Tustervatn in Norway (65.83°N, 13.92°E, 439m a.s.l.), by diagnosing the origin of moisture...

  1. Fever of Unknown Origin in Childhood.

    Science.gov (United States)

    Chusid, Michael J

    2017-02-01

    Childhood fever of unknown origin (FUO) is most often related to an underlying infection but can also be associated with a variety of neoplastic, rheumatologic, and inflammatory conditions. Repeated, focused reviews of patient history and physical examination are often helpful in suggesting a likely diagnosis. Diagnostic workup should be staged, usually leaving invasive testing for last. Advances in molecular genetic techniques have increased the importance of these assays in the diagnosis of FUO in children. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Infectious causes of fever of unknown origin.

    Science.gov (United States)

    McGregor, Alastair C; Moore, David A

    2015-06-01

    The causes of fever of unknown origin (FUO) are changing because advances in clinical practice and diagnostics have facilitated the identification of some infections. A variety of bacterial infections can cause FUO, and these can be divided into those that are easy to identify using culture and those that require serological or molecular tests for identification. A number of viral, parasitic and fungal infections can also cause prolonged fever. This article summarises the clinical features and diagnostic strategy of these infections. © Royal College of Physicians 2015. All rights reserved.

  3. Fever of unknown origin in cancer patients.

    Science.gov (United States)

    Loizidou, A; Aoun, M; Klastersky, J

    2016-05-01

    Fever of unknown origin (FUO) remains a challenging clinical problem, namely in patients with cancer. In cancer patients, FUO may be due to the cancer itself, as it is the case of hematological malignancies; digestive tumors (colon cancer, liver metastases) are significantly associated with FUO and infection can be demonstrated in some cases. Prevention with G-CSF and empirical antimicrobial therapy are essential approaches for the management of FUO in cancer patients. New diagnostic approaches, such as PET imaging, should be further evaluated in cancer patients with FUO. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. Chest pain of cardiac and noncardiac origin.

    Science.gov (United States)

    Lenfant, Claude

    2010-10-01

    Chest pain is one of the most common symptoms driving patients to a physician's office or the hospital's emergency department. In approximately half of the cases, chest pain is of cardiac origin, either ischemic cardiac or nonischemic cardiac disease. The other half is due to noncardiac causes, primarily esophageal disorder. Pain from either origin may occur in the same patient. In addition, psychological and psychiatric factors play a significant role in the perception and severity of the chest pain, irrespective of its cause. Chest pain of ischemic cardiac disease is called angina pectoris. Stable angina may be the prelude of ischemic cardiac disease; and for this reason, it is essential to ensure a correct diagnosis. In most cases, further testing, such as exercise testing and angiography, should be considered. The more severe form of chest pain, unstable angina, also requires a firm diagnosis because it indicates severe coronary disease and is the earliest manifestation of acute myocardial infarction. Once a diagnosis of stable or unstable angina is established, and if a decision is made not to use invasive therapy, such as coronary bypass, percutaneous transluminal coronary angioplasty, or stent insertion, effective medical treatment of associated cardiac risk factors is a must. Acute myocardial infarction occurring after a diagnosis of angina greatly increases the risk of subsequent death. Chest pain in women warrants added attention because women underestimate their likelihood to have coronary heart disease. A factor that complicates the clinical assessment of patients with chest pain (both cardiac and noncardiac in origin) is the relatively common presence of psychological and psychiatric conditions such as depression or panic disorder. These factors have been found to cause or worsen chest pain; but unfortunately, they may not be easily detected. Noncardiac chest pain represents the remaining half of all cases of chest pain. Although there are a number of

  5. 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

  6. On the origin of the liver

    Science.gov (United States)

    Friedman, Joshua R.; Kaestner, Klaus H.

    2011-01-01

    While it has been well established that the fetal liver originates from foregut endoderm, the identity of the mechanisms that maintain liver mass under both basal and injury conditions remains controversial. Dramatically different models have been proposed based on the experimental design employed. In this issue of the JCI, Malato and colleagues report their elegant new model for genetic lineage tracing of mature mouse hepatocytes using an adenoassociated virus–driven Cre recombinase. They show convincingly that maintenance of liver mass during normal turnover or in response to mild injury is achieved by mature hepatocytes, rather than cholangiocytes or specialized progenitor cells, as has been suggested by others. PMID:22105167

  7. Origin of cells and network information

    Institute of Scientific and Technical Information of China (English)

    Shihori Tanabe

    2015-01-01

    All cells are derived from one cell, and the origin ofdifferent cell types is a subject of curiosity. Cells constructlife through appropriately timed networks at each stageof development. Communication among cells andintracellular signaling are essential for cell differentiationand for life processes. Cellular molecular networksestablish cell diversity and life. The investigation ofthe regulation of each gene in the genome within thecellular network is therefore of interest. Stem cellsproduce various cells that are suitable for specificpurposes. The dynamics of the information in thecellular network changes as the status of cells isaltered. The components of each cell are subject toinvestigation.

  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.

  10. [Origin and development of qigong-wuqinxi].

    Science.gov (United States)

    Yang, Yi-Wang; Wu, Hong-Zhou

    2011-09-01

    Qigong-Wuqinxi originated from people's imitation of animals in ancient times. It was compiled by Huatuo, a famous doctor in the Eastern Han Dynasty. During the Tang and Song periods, Qigong-Wuqinxi was popular and was mentioned in many poems. People put Qigong-Wuqinxi into some order during the Ming-Qing Dynasty and the period of the Republic of China. Pictures were added combined with text. In the 21st century, Qigong-Wuqinxi was divided into many types. In order to popularize it, the General Administration of Sport arranged and standardized Wuqinxi again.

  11. 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.

  12. Alkoholituotteen tuotteistaminen ja markkinointi : Ufo Shot Original

    OpenAIRE

    Pikkarainen, Joonas

    2013-01-01

    Opinnäytetyössä käsitellään Ufo Shot Original – alkoholituotteen tuotekehitystä ja lanseerausta. Prosessin tavoite oli kehittää tuoteideasta Suomen alkoholimarkkinoilla menestyvä tuote. Ensisijainen tavoite oli ravintolamyynnin kasvatus, jonka kautta tuotteelle haettiin näkyvyyttä ja saatavuutta. Pidempi aikainen tavoite oli saada tuote Alkon valikoimiin. Opinnäytetyön tarkoitus on luoda käytännön esimerkki aloittavan yrityksen toiminnan alkuvaiheista. Opinnäytetyössä kuvattu prosessi sijoitt...

  13. 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.

  14. Raoultella planticola bacteremia of gastrointestinal origin

    Directory of Open Access Journals (Sweden)

    Ramírez-Quintero, Juan David

    2017-01-01

    Full Text Available Raoultella planticola, a bacteria found in water and soil, is rarely associated to human disease, mostly bacteremia and gastrointestinal infections. It is usually related with health care procedures or affects patients with malignant biliary disease. If properly treated, this infection is usually benign, but the germ must not be disregarded as an innocent bystander because it has homology with Klebsiella spp., and therefore the potential to acquire antimicrobial resistance mechanisms like bla KPC genes. We report the case of a patient with community-aquired R. planticola bacteremia of gastrointestinal origin.

  15. Cells of Origin of Epithelial Ovarian Cancers

    Science.gov (United States)

    2015-09-01

    AWARD NUMBER: W81XWH-14-1-0280 TITLE: Cells of Origin of Epithelial Ovarian Cancers PRINCIPAL INVESTIGATOR: Zhe Li, PhD CONTRACTING...Xie, Zhe Li 5d. PROJECT NUMBER 5e. TASK NUMBER E-Mail: zli4@rics.bwh.harvard.edu 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND...Lined Inclusion Cysts or Teratomas. PLoS ONE 8, e65067. Sherman-Baust, C.A., Kuhn, E., Valle, B.L., Shih Ie, M., Kurman, R.J., Wang , T.L., Amano, T

  16. The Atomic Origin of the Reflection Law

    Science.gov (United States)

    Prytz, Kjell

    2016-12-01

    It will be demonstrated how the reflection law may be derived on an atomic basis using the plane wave approximation together with Huygens' principle. The model utilized is based on the electric dipole character of matter originating from its molecular constituents. This approach is not new but has, since it was first introduced by Ewald and Oseen in 1915, been applied and analyzed many times before. Here we develop the Ewald-Oseen model of reflection adapted for high school and early undergraduate students with a basic knowledge of microscopic material structure.

  17. Genomics and the origin of species.

    Science.gov (United States)

    Seehausen, Ole; Butlin, Roger K; Keller, Irene; Wagner, Catherine E; Boughman, Janette W; Hohenlohe, Paul A; Peichel, Catherine L; Saetre, Glenn-Peter; Bank, Claudia; Brännström, Ake; Brelsford, Alan; Clarkson, Chris S; Eroukhmanoff, Fabrice; Feder, Jeffrey L; Fischer, Martin C; Foote, Andrew D; Franchini, Paolo; Jiggins, Chris D; Jones, Felicity C; Lindholm, Anna K; Lucek, Kay; Maan, Martine E; Marques, David A; Martin, Simon H; Matthews, Blake; Meier, Joana I; Möst, Markus; Nachman, Michael W; Nonaka, Etsuko; Rennison, Diana J; Schwarzer, Julia; Watson, Eric T; Westram, Anja M; Widmer, Alex

    2014-03-01

    Speciation is a fundamental evolutionary process, the knowledge of which is crucial for understanding the origins of biodiversity. Genomic approaches are an increasingly important aspect of this research field. We review current understanding of genome-wide effects of accumulating reproductive isolation and of genomic properties that influence the process of speciation. Building on this work, we identify emergent trends and gaps in our understanding, propose new approaches to more fully integrate genomics into speciation research, translate speciation theory into hypotheses that are testable using genomic tools and provide an integrative definition of the field of speciation genomics.

  18. Intrascrotal Dedifferentiated Leiomyosarcoma Originating from Dartos Muscle

    Directory of Open Access Journals (Sweden)

    Taro Teshima

    2014-01-01

    Full Text Available A 46-year-old man, who had visited our hospital complaining of a small intrascrotal nodule ten years ago, returned to us because of the rapid growth of the nodule. Computed tomography revealed a heterogeneously enhanced intrascrotal tumor of approximately 4×3 cm. The tumor and the right testis were excised with the adhered right scrotal skin. The pathological diagnosis was pleomorphic leiomyosarcoma with dedifferentiation originating from the dartos muscle. Urological dedifferentiated leiomyosarcomas are rarely reported and the clinical features are mostly unknown. This is the first report to describe the dedifferentiated leiomyosarcoma of the dartos muscle.

  19. Origin of Synthetic Particles in Honeys

    Directory of Open Access Journals (Sweden)

    Liebezeit Gerd

    2015-06-01

    Full Text Available A total of 47 honeys and 22 flowering plants was analysed for their load of synthetic fibres and fragments. In all samples investigated foreign particles were found. These include also black carbon particles which were not enumerated. Fibres and fragments ranged from 10 to 336 kg-1 and 2 to 82 kg-1 honey, respectively. The data of the flowering plants analysed indicate that a major proportion of the particle load may originate from external sources, i.e. these particles are brought into the beehive by the worker bees during nectar collection.

  20. Flavor origin of R-parity

    CERN Document Server

    Morisi, S; Vicente, A

    2013-01-01

    Proton stability is guaranteed in the MSSM by assuming a discrete symmetry, R-parity. However, there are additional R-parity conserving higher dimensional operators which violate lepton and baryon numbers and induce fast proton decay. Here we study the possibility that all renormalizable, as well as the most dangerous non-renormalizable, R-parity violating operators are forbidden by a flavor symmetry, providing a common origin for fermion mixing and proton and dark matter stability. We propose a specific model based on the Delta(27) discrete symmetry.

  1. 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.

  2. Supernova-Remnant Origin of Cosmic Rays?

    CERN Document Server

    Butt, Y M; Romero, G E; Dame, T M; Combi, J A; Butt, Yousaf M.; Torres, Diego F.; Romero, Gustavo E.; Dame, Thomas M.; Combi, Jorge A.

    2002-01-01

    It is thought that Galactic cosmic ray (CR) nuclei are gradually accelerated to high energies (up to ~300 TeV/nucleon, where 1TeV=10^12eV) in the expanding shock-waves connected with the remnants of powerful supernova explosions. However, this conjecture has eluded direct observational confirmation^1,2 since it was first proposed in 1953 (ref. 3). Enomoto et al.^4 claim to have finally found definitive evidence that corroborates this model, proposing that the very-high-energy, TeV-range, gamma-rays from the supernova remnant (SNR) RX J1713.7-3946 are due to the interactions of energetic nuclei in this region. Here we argue that their claim is not supported by the existing multiwavelength spectrum of this source. The search for the origin(s) of Galactic cosmic ray nuclei may be closing in on the long-suspected supernova-remnant sources, but it is not yet over.

  3. Origin of Dynamical Quantum Non-locality

    Science.gov (United States)

    Pachon, Cesar E.; Pachon, Leonardo A.

    2014-03-01

    Non-locality is one of the hallmarks of quantum mechanics and is responsible for paradigmatic features such as entanglement and the Aharonov-Bohm effect. Non-locality comes in two ``flavours'': a kinematic non-locality- arising from the structure of the Hilbert space- and a dynamical non-locality- arising from the quantum equations of motion-. Kinematic non-locality is unable to induce any change in the probability distributions, so that the ``action-at-a-distance'' cannot manifest. Conversely, dynamical non-locality does create explicit changes in probability, though in a ``causality-preserving'' manner. The origin of non-locality of quantum measurements and its relations to the fundamental postulates of quantum mechanics, such as the uncertainty principle, have been only recently elucidated. Here we trace the origin of dynamical non-locality to the superposition principle. This relation allows us to establish and identify how the uncertainty and the superposition principles determine the non-local character of the outcome of a quantum measurement. Being based on group theoretical and path integral formulations, our formulation admits immediate generalizations and extensions to to, e.g., quantum field theory. This work was supported by the Departamento Administrativo de Ciencia, Tecnologia e Innovacion -COLCIENCIAS- of Colombia under the grant number 111556934912.

  4. 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.

  5. The origin of lunar concentric craters

    Science.gov (United States)

    Trang, David; Gillis-Davis, Jeffrey J.; Hawke, B. Ray

    2016-11-01

    Lunar concentric craters are a unique class of impact craters because the interior of the craters contains a concentric ridge, but their formation mechanism is unknown. In order to determine the origin of concentric craters, we examined multiple working hypotheses, which include eight impact-related and endogenic processes. We analyzed data sets that originated from instruments onboard Clementine, Kaguya, and the Lunar Reconnaissance Orbiter to characterize the morphology, spatial distribution, composition, and absolute model ages of 114 concentric craters. Concentric craters contain five key properties: (1) a concentric ridge, (2) anomalously shallow floors, (3) their occurrence is concentrated near mare margins and in mare pond regions (4) the concentric ridge composition is similar to the surrounding area and (5) concentric crater ages are Eratosthenian and older. These five key properties served as constraints for testing impact-related and endogenic mechanisms of formation. We find that most impact-related hypotheses cannot explain the spatial and age distribution of concentric craters. As for endogenic hypotheses, we deduce that igneous intrusions are the likely mechanism that formed concentric craters because of the close relationship between concentric craters and floor-fractured craters and the concentration of both features near mare-highland boundaries and in mare ponds. Furthermore, we observe that floor-fractured craters are common at crater diameters > 15 km, whereas concentric craters are common at crater diameters 15 km) produce floor-fractured craters.

  6. 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.

  7. The origin of the galaxy color bimodality

    Science.gov (United States)

    Aragón-Calvo, M. A.; Neyrinck, Mark C.; Silk, Joseph

    2016-10-01

    The star formation history of galaxies is a complex process usually considered to be stochastic in nature, for which we can only give average descriptions such as the color-density relation. In this work we follow star-forming gas particles in a hydrodynamical N-body simulation back in time in order to study their initial spatial configuration. By keeping record of the time when a gas particle started forming stars we can produce Lagrangian gas-star isochrone surfaces delineating the surfaces of accreting gas that begin producing stars at different times. These surfaces form a complex a network of filaments in Eulerian space from which galaxies accrete cold gas. Lagrangian accretion surfaces are closely packed inside dense regions, intersecting each other, and as a result galaxies inside proto-clusters stop accreting gas early, naturally explaining the color dependence on density. The process described here has a purely gravitational / geometrical origin, arguably operating at a more fundamental level than complex processes such as AGN and supernovae, and providing a conceptual origin for the color-density relation.

  8. 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.

  9. SULLA ORIGINE DEI MICROSISMI DEL MEDITERRANEO

    Directory of Open Access Journals (Sweden)

    e. rosini

    1951-06-01

    Full Text Available La nota contiene i risultati di indagini particolareggiate condottepresso l'Istituto Nazionale di Geofisica con la collaborazione del ServizioMeteorologico dell' Aeronautica sul problema dell' origine dei microsismi.Lo studio concerne fondamentalmente i tnicrosismi aventiorigine nel Mediterraneo perché questo è il settore per cui maggioreera la abbondanza dei dati meteorologici e di più diretto controllo.L'osservazione continua di oltre tre anni conferma oramai il risultatopiù importante: i microsismi di origine mediterranea non sono indiretta correlazione con i fronti bensì vengono generati nelle zone,in mare aperto, interessale da nuclei di tendenza barometrica positiva.Si riporta, a titolo di esempio, la documentazione relativa ad alcunetempeste microsismiche. Si dà poi una interpretazione delle modalitàdi generazione dei microsismi stessi e della trasmissione dellaenergia dall'atmosfera, attraverso le masse marine, al fondo solido dell'Oceano.Ricerche estese all'analisi dei sondaggi termodinamici stanno adindicare che l'effetto massimo si ha quando lo spessore della massafredda turbolenta è fra 1 e 3 km.

  10. Foreign Workers in Croatia: Origin, Status, Orientation

    Directory of Open Access Journals (Sweden)

    Saša Božić

    2013-12-01

    Full Text Available In the public discourse Croatia is primarily seen as a country of emigration rather than immigration but the trends of labour mobility in the past decade indicate that Croatia is no longer only a country of emigration. It is increasingly becoming a country of labour immigration, although the number of (registered foreign workers is not large. Since there are no data on the origin, status, quality of life and orientations of foreign workers in Croatia, this exploratory research is focused on acquiring the first insights into their social position within Croatian society. The research determined the basic demographic characteristics of foreign workers, their geographical origin, reasons for their immigration, main trends in social exclusion and discrimination, as well as the sustainability of their immigration. In addition, the research gave insights into social ties and contacts of foreign workers within Croatian society, as well as their ties with relatives and friends in other countries. Finally, the life plans and orientation of immigrants were disclosed.

  11. Synthetic Origin of Tramadol in the Environment.

    Science.gov (United States)

    Kusari, Souvik; Tatsimo, Simplice Joel N; Zühlke, Sebastian; Spiteller, Michael

    2016-01-04

    The presence of tramadol in roots of Sarcocephalus latifolius trees in Northern Cameroon was recently attributed to point contamination with the synthetic compound. The synthetic origin of tramadol in the environment has now been unambiguously confirmed. Tramadol samples isolated from tramadol pills bought at a street market in downtown Maroua and highly contaminated soil at Houdouvou were analyzed by high-precision (14)C measurements by accelerator mass spectrometry ((14)C AMS): Tramadol from the pills did not contain any radiocarbon, thus indicating that it had been synthesized from (14)C-free petroleum-derived precursors. Crucially, tramadol isolated from the soil was also radiocarbon-free. As all biosynthetic plant compounds must contain radiocarbon levels close to that of the contemporary environment, these results thus confirm that tramadol isolated from the soil cannot be plant-derived. Analyses of S. latifolius seeds, in vitro grown plants, plants from different origins, and stable-isotope labeling experiments further confirmed that synthetic tramadol contaminates the environment.

  12. 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.

  13. 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.

  14. Origin of the numerals, Al biruni testimony

    CERN Document Server

    Boucenna, Ahmed

    2007-01-01

    The origin of the numerals that we inherited from the arabo-Islamic civilization remained one enigma. The hypothesis of the Indian origin remained, with controversies, without serious rival. It was the dominant hypothesis since more of one century. Its partisans found to it and constructed a lot of arguments. The testimonies of the medieval authors have been interpreted to its advantage. The opposite opinions have been dismissed and ignored. An amalgam between the history of our modern numerals and the Indian mathematics history is made. Rational contradictions often passed under silence. A meticulous observation of the numerals permits to affirm that our numerals are in fact more or less modified Arabic letters. The "Ghubari" shape of the numerals shows that the symbol of a numeral corresponds to the Arabic letter whose numerical value is equal to this numeral. The numerals don't have a simple resemblance with some Arabic letters, but every number looks like the Arabic letter whose numerical value is equal t...

  15. [The origins of occupational therapy in Spain].

    Science.gov (United States)

    Pérez de Heredia-Torres, M; Brea-Rivero, M; Martínez-Piédrola, R M

    Occupational therapy is a young discipline in many aspects, but since ancient times an important number of reports have appeared in the health sciences literature and in the early days of neurology and psychiatry that can shed light on the origins and the fundamental principles that underlie this profession today. We have gathered examples that show how the philosophy and the clinical practice of the procedures used in occupational therapy stem from the process of humanising medical care. After analysing the information currently available to us on the history of the influence of humanism on the development of medicine in Spain, the authors believe they have found enough evidence to identify the precursors of occupational therapy at that point in history. Our study examines facts that appear to situate the earliest evidence of occupational therapy at the origins of Spanish neurology and psychiatry in the 15th century, and which were later to have such a powerful influence on the birth of certain aspects of Pinel's moral treatment. If we accept 'moral treatment' as being one of the main forerunners of occupational therapy, and if we take into account that the humanitarian way patients were dealt with in Spanish neurological and psychiatric institutions and hospitals in the 15th century had a notable influence on the principles that regulated that 'moral treatment', then it is reasonable to state that the earliest evidence of occupational therapy is to be found in the development of humanisation within Spanish medical care.

  16. Nepalese origin of cholera epidemic in Haiti.

    Science.gov (United States)

    Frerichs, R R; Keim, P S; Barrais, R; Piarroux, R

    2012-06-01

    Cholera appeared in Haiti in October 2010 for the first time in recorded history. The causative agent was quickly identified by the Haitian National Public Health Laboratory and the United States Centers for Disease Control and Prevention as Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Since then, >500 000 government-acknowledged cholera cases and >7000 deaths have occurred, the largest cholera epidemic in the world, with the real death toll probably much higher. Questions of origin have been widely debated with some attributing the onset of the epidemic to climatic factors and others to human transmission. None of the evidence on origin supports climatic factors. Instead, recent epidemiological and molecular-genetic evidence point to the United Nations peacekeeping troops from Nepal as the source of cholera to Haiti, following their troop rotation in early October 2010. Such findings have important policy implications for shaping future international relief efforts. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

  17. 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.

  18. Inversion concept of the origin of life.

    Science.gov (United States)

    Kompanichenko, V N

    2012-06-01

    The essence of the inversion concept of the origin of life can be narrowed down to the following theses: 1) thermodynamic inversion is the key transformation of prebiotic microsystems leading to their transition into primary forms of life; 2) this transformation might occur only in the microsystems oscillating around the bifurcation point under far-from-equilibrium conditions. The transformation consists in the inversion of the balance "free energy contribution / entropy contribution", from negative to positive values. At the inversion moment the microsystem radically reorganizes in accordance with the new negentropy (i.e. biological) way of organization. According to this approach, the origin-of-life process on the early Earth took place in the fluctuating hydrothermal medium. The process occurred in two successive stages: a) spontaneous self-assembly of initial three-dimensional prebiotic microsystems composed mainly of hydrocarbons, lipids and simple amino acids, or their precursors, within the temperature interval of 100-300°C (prebiotic stage); b) non-spontaneous synthesis of sugars, ATP and nucleic acids started at the inversion moment under the temperature 70-100°C (biotic stage). Macro- and microfluctuations of thermodynamic and physico-chemical parameters able to sustain this way of chemical conversion have been detected in several contemporary hydrothermal systems. A minimal self-sufficient unit of life on the early Earth was a community of simplest microorganisms (not a separate microorganism).

  19. 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.

  20. The Origins of Transmembrane Ion Channels

    Science.gov (United States)

    Pohorille, Andrew; Wilson, Michael A.

    2012-01-01

    Even though membrane proteins that mediate transport of ions and small molecules across cell walls are among the largest and least understood biopolymers in contemporary cells, it is still possible to shed light on their origins and early evolution. The central observation is that transmembrane portions of most ion channels are simply bundles of -helices. By combining results of experimental and computer simulation studies on synthetic models and natural channels, mostly of non-genomic origin, we show that the emergence of -helical channels was protobiologically plausible, and did not require highly specific amino acid sequences. Despite their simple structure, such channels could possess properties that, at the first sight, appear to require markedly larger complexity. Specifically, we explain how the antiamoebin channels, which are made of identical helices, 16 amino acids in length, achieve efficiency comparable to that of highly evolved channels. We further show that antiamoebin channels are extremely flexible, compared to modern, genetically coded channels. On the basis of our results, we propose that channels evolved further towards high structural complexity because they needed to acquire stable rigid structures and mechanisms for precise regulation rather than improve efficiency. In general, even though architectures of membrane proteins are not nearly as diverse as those of water-soluble proteins, they are sufficiently flexible to adapt readily to the functional demands arising during evolution.

  1. Tracing the origin of Arctic driftwood

    Science.gov (United States)

    Hellmann, Lena; Tegel, Willy; Eggertsson, Ã.`Lafur; Schweingruber, Fritz Hans; Blanchette, Robert; Kirdyanov, Alexander; GäRtner, Holger; Büntgen, Ulf

    2013-03-01

    Arctic environments, where surface temperatures increase and sea ice cover and permafrost depth decrease, are very sensitive to even slight climatic variations. Placing recent environmental change of the high-northern latitudes in a long-term context is, however, complicated by too short meteorological observations and too few proxy records. Driftwood may represent a unique cross-disciplinary archive at the interface of marine and terrestrial processes. Here, we introduce 1445 driftwood remains from coastal East Greenland and Svalbard. Macroscopy and microscopy were applied for wood anatomical classification; a multi-species subset was used for detecting fungi; and information on boreal vegetation patterns, circumpolar river systems, and ocean current dynamics was reviewed and evaluated. Four conifer (Pinus, Larix, Picea, and Abies) and three deciduous (Populus, Salix, and Betula) genera were differentiated. Species-specific identification also separated Pinus sylvestris and Pinus sibirica, which account for ~40% of all driftwood and predominantly originate from western and central Siberia. Larch and spruce from Siberia or North America represents ~26% and ~18% of all materials, respectively. Fungal colonization caused different levels of driftwood staining and/or decay. Our results demonstrate the importance of combining wood anatomical knowledge with insight on boreal forest composition for successfully tracing the origin of Arctic driftwood. To ultimately reconstruct spatiotemporal variations in ocean currents, and to better quantify postglacial uplift rates, we recommend consideration of dendrochronologically dated material from many more circumpolar sites.

  2. RNA relics and origin of life.

    Science.gov (United States)

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

    2009-07-31

    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.

  3. Hematopoietic Origin of Murine Lung Fibroblasts

    Directory of Open Access Journals (Sweden)

    Lindsay T. McDonald

    2015-01-01

    Full Text Available Multiple origins, including the bone marrow, have been suggested to contribute to fibroblast populations in the lung. Using bone marrow reconstitution strategies, the present study tested the hypothesis that the bone marrow hematopoietic stem cell (HSC gives rise to lung tissue fibroblasts in vivo. Data demonstrate that the nonadherent bone marrow fraction is enriched for CD45+ HSC-derived cells and was able to reconstitute hematopoiesis in lethally irradiated animals. Analysis of peripheral blood and lung tissues from engrafted mice demonstrated the ability of this population to give rise to CD45+/Discoidin-Domain Receptor-2+ (DDR2 circulating fibroblast precursors (CFPs in blood and fibroblast populations in lung. An HSC origin for lung fibroblasts was confirmed using a novel clonal cell transplantation method in which the bone marrow is reconstituted by a clonal population derived from a single HSC. Together, these findings provide evidence for an HSC contribution to lung fibroblasts and demonstrate a circulating intermediate through the CD45+/DDR2+ HSC-derived CFP.

  4. Legal Origin,Endowment and Financial Development%Legal Origin, Endowment and Financial Development

    Institute of Scientific and Technical Information of China (English)

    张世雯

    2016-01-01

    Since the rise of the economic and financial development theory, around economic and financial development of the determinants and what financial arrangements for promoting economic growth and other issues, thus resulted in a variety of im-portant theoretical debate. This paper will Define what is meant by key terms such as legal tradition and endowment, explain the channels through which legal tradition and endowment affect financial development through talking about the relationship be-tween legal origin, initial in endowment and financial development. By comparing different legal traditions or the"Origins"be-tween the The Continental Law System and Common Law System, a comprehensive analysis of the effects of different origin of law on the financial and economic development.

  5. Origin, dispersal, cultivation and variation of rice.

    Science.gov (United States)

    Khush, G S

    1997-09-01

    There are two cultivated and twenty-one wild species of genus Oryza. O. sativa, the Asian cultivated rice is grown all over the world. The African cultivated rice, O. glaberrima is grown on a small scale in West Africa. The genus Oryza probably originated about 130 million years ago in Gondwanaland and different species got distributed into different continents with the breakup of Gondwanaland. The cultivated species originated from a common ancestor with AA genome. Perennial and annual ancestors of O. sativa are O. rufipogon and O. nivara and those of O. glaberrima are O. longistaminata, O. breviligulata and O. glaberrima probably domesticated in Niger river delta. Varieties of O. sativa are classified into six groups on the basis of genetic affinity. Widely known indica rices correspond to group I and japonicas to group VI. The so called javanica rices also belong to group VI and are designated as tropical japonicas in contrast to temperate japonicas grown in temperate climate. Indica and japonica rices had a polyphyletic origin. Indicas were probably domesticated in the foothills of Himalayas in Eastern India and japonicas somewhere in South China. The indica rices dispersed throughout the tropics and subtropics from India. The japonica rices moved northward from South China and became the temperate ecotype. They also moved southward to Southeast Asia and from there to West Africa and Brazil and became tropical ecotype. Rice is now grown between 55 degrees N and 36 degrees S latitudes. It is grown under diverse growing conditions such as irrigated, rainfed lowland, rainfed upland and floodprone ecosystems. Human selection and adaptation to diverse environments has resulted in numerous cultivars. It is estimated that about 120,000 varieties of rice exist in the world. After the establishment of International Rice Research Institute in 1960, rice varietal improvement was intensified and high yielding varieties were developed. These varieties are now planted to 70

  6. The origins of phagocytosis and eukaryogenesis

    Directory of Open Access Journals (Sweden)

    Wolf Yuri I

    2009-02-01

    Full Text Available Abstract Background Phagocytosis, that is, engulfment of large particles by eukaryotic cells, is found in diverse organisms and is often thought to be central to the very origin of the eukaryotic cell, in particular, for the acquisition of bacterial endosymbionts including the ancestor of the mitochondrion. Results Comparisons of the sets of proteins implicated in phagocytosis in different eukaryotes reveal extreme diversity, with very few highly conserved components that typically do not possess readily identifiable prokaryotic homologs. Nevertheless, phylogenetic analysis of those proteins for which such homologs do exist yields clues to the possible origin of phagocytosis. The central finding is that a subset of archaea encode actins that are not only monophyletic with eukaryotic actins but also share unique structural features with actin-related proteins (Arp 2 and 3. All phagocytic processes are strictly dependent on remodeling of the actin cytoskeleton and the formation of branched filaments for which Arp2/3 are responsible. The presence of common structural features in Arp2/3 and the archaeal actins suggests that the common ancestors of the archaeal and eukaryotic actins were capable of forming branched filaments, like modern Arp2/3. The Rho family GTPases that are ubiquitous regulators of phagocytosis in eukaryotes appear to be of bacterial origin, so assuming that the host of the mitochondrial endosymbiont was an archaeon, the genes for these GTPases come via horizontal gene transfer from the endosymbiont or in an earlier event. Conclusion The present findings suggest a hypothetical scenario of eukaryogenesis under which the archaeal ancestor of eukaryotes had no cell wall (like modern Thermoplasma but had an actin-based cytoskeleton including branched actin filaments that allowed this organism to produce actin-supported membrane protrusions. These protrusions would facilitate accidental, occasional engulfment of bacteria, one of which

  7. 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

  8. Formamide and the origin of life.

    Science.gov (United States)

    Saladino, Raffaele; Crestini, Claudia; Pino, Samanta; Costanzo, Giovanna; Di Mauro, Ernesto

    2012-03-01

    The complexity of life boils down to the definition: "self-sustained chemical system capable of undergoing Darwinian evolution" (Joyce, 1994) [1]. The term "self-sustained" implies a set of chemical reactions capable of harnessing energy from the environment, using it to carry out programmed anabolic and catabolic functions. We briefly present our opinion on the general validity of this definition. Running anabolic and catabolic functions entails complex chemical information whose stability, reproducibility and evolution constitute the core of what is dubbed genetics. Life as-we-know-it is made of the intimate interaction of metabolism and genetics, both built around the chemistry of the most common elements of the Universe (hydrogen, oxygen, nitrogen, carbon). Other elements like phosphorus and sulphur play important but ancillary and potentially replaceable roles. The reproducible interaction of metabolic and genetic cycles results in the hypercycles of organization and de-organization of chemical information that we consider living entities. In order to approach the problem of the origin of life it is therefore reasonable to start from the assumption that both metabolism and genetics had a common origin, shared a common chemical frame, were embedded in physical-chemical conditions favourable for the onset of both. The most abundant three-atoms organic compound in interstellar environment is hydrogen cyanide HCN, the most abundant three-atoms inorganic compound is water H(2)O. The combination of the two results in the formation of formamide H(2)NCOH. We have explored the chemistry of formamide in conditions compatible with the synthesis and the stability of compounds of potential pre-genetic and pre-metabolic interest. We discuss evidence showing (i) that all the compounds necessary for the build-up of nucleic acids are easily obtained abiotically, (ii) that essentially all the steps leading to the spontaneous generation of RNA are abiotically possible, (iii

  9. 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

  10. 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).

  11. 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...... for hypospadias, especially in genetically predisposed individuals. So far, however, no environmental chemical pollutants or endocrine disruptor with a general common impact on the risk for hypospadias in most societies has been demonstrated. SUMMARY: A major point that should be considered regarding the action...... of environmental toxicants in inducing hypospadias is the cumulative effects of multiple low-dose exposures. Furthermore, interactions between genetic and environmental factors may help to explain nonreplication in genetic studies of hypospadias....

  12. 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.

  13. Cosmology and the origin of structure

    CERN Document Server

    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

  14. Dynamic Origin of Evolution and Social Transformation

    CERN Document Server

    Kirilyuk, Andrei P

    2012-01-01

    We analyse the unreduced, nonperturbative dynamics of an arbitrary many-body interaction process with the help of the generalised effective potential method and reveal the well-specified universal origin of change (emergence), time and evolution in an a priori conservative, time-independent system. It appears together with the universal dynamic complexity definition, where this unified complexity conservation and transformation constitutes the essence of evolution. We then consider the detailed structure of this universal evolutionary process showing its step-wise, "punctuated" character, now provided with the exact mathematical description. Comparing the expected features of a revolutionary complexity transition near a step-like complexity upgrade with the currently observed behaviour of world's social and economic systems, we prove the necessity of complexity revolution towards the superior civilisation level of well-defined nature, the only alternative being an equally dramatic and irreversible degradation...

  15. Evidence for a dynamic origin of charge

    CERN Document Server

    Hofer, W A

    2000-01-01

    The fundamental equations of particle motion lead to a modified Poisson equation including dynamic charge. This charge derives from density oscillations of a particle; it is not discrete, but continuous. Within the dynamic model of hydrogen it accounts for all features of electron proton interactions, its origin are density oscillations of the proton. We propose a new system of electromagnetic units, based on meter, kilogram, and second, bearing on these findings. The system has none of the disadvantages of traditional three-unit systems. On the basis of our theoretical model we can genuinely derive the scaling factor between electromagnetic and mechanic variables, which is equal, within a few percent, to Planck's constant h. The implications of the results in view of unifying gravity and quantum theory are discussed. It seems that the hypothetical solar gravity field, in the very low frequency range of the electromagnetic spectrum, is open to experimental detection.

  16. 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.

  17. 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.

  18. Paleoparasitology: the origin of human parasites.

    Science.gov (United States)

    Araújo, Adauto; Reinhard, Karl; Ferreira, Luiz Fernando; Pucu, Elisa; Chieffi, Pedro Paulo

    2013-09-01

    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.

  19. A Physician's Nightmare: Fever of Unknown Origin.

    Science.gov (United States)

    Din, Sana; Anwer, Farrukh; Beg, Mirza

    2016-01-01

    Fever of unknown origin (FUO) remains to be a challenge despite advancement in diagnostic technologies and procedures. FUO is considered when fever presents intermittently without an explanation. It has been linked to various etiologies, which makes it difficult to diagnose. We present the case of 18-month-old female with recurrent fever, splenomegaly, abdominal pain, and constipation. The workup for her symptoms revealed wandering spleen. Wandering spleen is a result from excessive laxity or absence of splenic ligaments. The patient underwent splenectomy and was advised to continue on Senna, Miralax, and high fiber diet. Her mother reported that the fever is no longer present and there is marked improvement in her constipation and abdominal pain after splenectomy.

  20. The origins and ends of giftedness.

    Science.gov (United States)

    Winner, E

    2000-01-01

    Five issues about giftedness are discussed. First, the origins of giftedness are explored. The view that giftedness is entirely a product of training is critiqued. There is indirect evidence for atypical brain organization and innate talent in gifted children: Many gifted children and savants have enhanced right-hemisphere development, language-related difficulties, and autoimmune disorders. Second, the intense motivation of gifted children is discussed. Third, it is argued that gifted children have social and emotional difficulties that set them apart. Fourth, evidence for the often uneven cognitive profiles of such children is presented. Finally, the relationship between childhood giftedness and "domain" creativity in adulthood is discussed. Few gifted children go on to become adult creators because the skills and personality factors required to be a creator are very different from those typical of even the most highly gifted children.