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Sample records for structure tn1546 typing

  1. Novel Structure of Enterococcus faecium-Originated ermB-Positive Tn1546-Like Element in Staphylococcus aureus.

    Science.gov (United States)

    Wan, Tsai-Wen; Hung, Wei-Chun; Tsai, Jui-Chang; Lin, Yu-Tzu; Lee, Hao; Hsueh, Po-Ren; Lee, Tai-Fen; Teng, Lee-Jene

    2016-10-01

    We determined the resistance determinants in 274 erythromycin-resistant methicillin-susceptible Staphylococcus aureus (MSSA) isolates during a 13-year period, 2000 to 2012. The resistance phenotypes, inducible macrolide-lincosamide-streptogramin (iMLS), constitutive MLS (cMLS), and macrolide-streptogramin (MS) resistance phenotypes, were examined by a double-disk diffusion D test. The ermB gene was more frequent (35%; 97/274) than ermC (27%; 75/274) or ermA (21%; 58/274). All 97 ermB-positive isolates harbored Tn551 and IS1216V The majority (89/97) of ermB-positive isolates displayed the cMLS phenotype and carried mobile element structure (MES)-like structures, which has been previously reported in sequence type 59 (ST59) methicillin-resistant S. aureus (MRSA). The remaining 8 ermB-carrying isolates, belonging to ST7 (n = 4), ST5 (n = 3), and ST59 (n = 1), were sasK intact and did not carry MES-like structures. Unlike a MES-like structure that was located on the chromosome, the ermB elements on sasK-intact isolates were located on plasmids by S1 nuclease pulsed-field gel electrophoresis (PFGE) analysis and conjugation tests. Sequence data for the ermB-containing region (14,566 bp) from ST59 NTUH_3874 revealed that the best match was a Tn1546-like element in plasmid pMCCL2 DNA (GenBank accession number AP009486) of Macrococcus caseolyticus Tn1546 is recognized as an enterococcal transposon and was known from the vancomycin resistance gene cluster in vancomycin-resistant Enterococcus (VRE). So far, acquisitions of Tn1546 in S. aureus have occurred in clonal complex 5 (CC5) MRSA, but not in MSSA. This is the first report that MSSA harbors an Enterococcus faecium-originated ermB-positive Tn1546-like element located on a plasmid. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  2. Analysis of VanA vancomycin-resistant Enterococcus faecium isolates from Saudi Arabian hospitals reveals the presence of clonal cluster 17 and two new Tn 1546 lineage types

    NARCIS (Netherlands)

    M.A. Khan (Mushtaq); M. van der Wal (Martin); D.J. Farrell (David); L. Cossins (Luke); A.F. van Belkum (Alex); A. Alaidan (Alwaleed); J.P. Hays (John)

    2008-01-01

    textabstractObjectives; The aim of this study was to characterize 34 vancomycin-resistant VanA Enterococcus faecium isolates obtained from two hospitals in Saudi Arabia and to assess Tn 1546 variation within these isolates. Methods: PFGE and multilocus sequence typing (MLST) genotypes, antibiotic

  3. Molecular analysis of Tn1546 in Enterococcus faecium isolated from animals and humans

    DEFF Research Database (Denmark)

    Jensen, Lars Bogø; Ahrens, Peter; Dons, L.

    1998-01-01

    The internal areas and the position of integration of the glycopeptide resistance element Tn1546 were characterized by using PCR fragment length polymorphism, sequencing, and DNA hybridization techniques with 38 high-level vancomycin-resistant Enterococcus faecium isolates of human and animal...... from the reference strain, BM4147. For type 2, 11 isolates of human and animal origins were found, Six human isolates from England were all of type 3. Two human isolates from the United States, indistinguishable from each other, were type 9. These results showed that vancomycin-resistant E. faecium...... of animal and human origins can contain indistinguishable genetic elements coding for vancomycin resistance, indicating either horizontal gene transfer between E. faecium organisms of human and animal origins or the existence of a common reservoir for glycopeptide resistance....

  4. Diversity of Tn1546 in vanA-positive Enterococcus faecium clinical isolates with VanA, VanB, and VanD phenotypes and susceptibility to vancomycin.

    Science.gov (United States)

    Cha, J O; Yoo, J I; Kim, H K; Kim, H S; Yoo, J S; Lee, Y S; Jung, Y H

    2013-10-01

    To investigate diversity in the vanA cluster in Enterococcus faecium isolates from nontertiary hospitals. We identified 43 vanA-positive Ent. faecium isolates, including two vancomycin-susceptible isolates, from hospitals between 2003 and 2006. Of these isolates, >85% were resistant to ampicillin, erythromycin and ciprofloxacin. The vanA cluster was classified into six types using overlapping PCR, but the prototype transposon Tn1546 was not found. Most vanA-positive vancomycin-resistant Enterococcus (VRE) carried IS1216V and belonged to Type III (58·1%) or Type II (20·9%). vanY, vanZ and IS1216V were observed in the left and right ends of Type III with long-range PCR. IS1216V was also observed within vanS and vanX in the two vancomycin-susceptible isolates and in two vancomycin-resistant isolates. No VRE isolates with VanB and VanD phenotypes contained point mutations in vanS, unlike in previous reports. Sequence types (STs) of all isolates belonged to clonal complex 17, and ST78 was predominant. Insertion sequences, especially IS1216V, cause structural variation in the vanA cluster. We report the first observation of vanY and vanZ at the left end of Tn1546 in clinical isolates. This is the first report of the frequency of vancomycin resistance and diversity of Tn1546 in vanA-positive Ent. faecium isolates from nontertiary hospitals. © 2013 The Society for Applied Microbiology.

  5. Human and Swine Hosts Share Vancomycin-Resistant Enterococcus faecium CC17 and CC5 and Enterococcus faecalis CC2 Clonal Clusters Harboring Tn1546 on Indistinguishable Plasmids

    DEFF Research Database (Denmark)

    Freitas, Ana R.; Coque, Teresa M.; Novais, Carla

    2011-01-01

    clonally related Enterococcus faecium clonal complex 5 (CC5) isolates (17 sequence type 6 [ST6], 6 ST5, 5 ST185, 1 ST147, and 1 ST493) were obtained from feces of swine and healthy humans. This collection included isolates widespread among pigs of European Union (EU) countries since the mid-1990s. Each ST...... resistance to vancomycin) and tcrB (coding for resistance to copper) were consistently located on 150- to 190-kb plasmids (rep(pLG1)). E. faecium CC17 (ST132) isolates from pig manure and two clinical samples showed identical PFGE profiles and contained a 60-kb mosaic plasmid (rep(Inc18) plus rep...... (rep(pRE25) plus rep(pCF10)) containing the whole Tn1546 backbone. The results indicate a current intra- and international spread of E. faecium and E. faecalis clones and their plasmids among swine and humans...

  6. Relevance of hot spots in the evolution and transmission of Tn1546 in glycopeptide-resistant Enterococcus faecium (GREF) from broiler origin

    DEFF Research Database (Denmark)

    Migura, Lourdes Garcia; Hasman, Henrik; Svendsen, Christina Aaby

    2008-01-01

    -resistant Enterococcus faecium isolated from broiler farms. Methods: Total DNA was digested, ligated and amplified using primers from inside Tn1546. The resulting amplicons were purified and sequenced. Two new primers were designed based on obtained sequences. Results: Two main insertion points have been repeatedly...

  7. Identification and molecular characterization of Van A-type vancomycin-resistant Enterococcus faecalis in Northeast of Brazil

    Directory of Open Access Journals (Sweden)

    Marinalda Anselmo Vilela

    2006-11-01

    Full Text Available The isolation of vancomycin resistant enterococci (VRE in Brazil has rapidly increased, following the world wide tendency. We report in the present study the first isolation of vancomycin resistant Enterococcus faecalis (VRE in the Northeast of Brazil. The four VRE isolates were characterized for antimicrobial susceptibility, genotypic typing by macro restriction of chromosomal DNA followed by pulsed-field gel electrophoresis and for characterization of the Tn1546-like element and plasmid contents. The isolates showed resistance to multiple antibiotics and a single genotype profile, suggesting the dissemination of a single clone among the patients. Tn1546 associated to genetic elements as plasmids shows the importance of infection control measures to avoid the spreading of glycopetide resistance by conjugative transfer of VanA elements.

  8. Organization of the cpe locus in CPE-positive clostridium perfringens type C and D isolates.

    Directory of Open Access Journals (Sweden)

    Jihong Li

    2010-06-01

    Full Text Available Clostridium perfringens enterotoxin (encoded by the cpe gene contributes to several important human, and possibly veterinary, enteric diseases. The current study investigated whether cpe locus organization in type C or D isolates resembles one of the three (one chromosomal and two plasmid-borne cpe loci commonly found amongst type A isolates. Multiplex PCR assays capable of detecting sequences in those type A cpe loci failed to amplify products from cpe-positive type C and D isolates, indicating these isolates possess different cpe locus arrangements. Therefore, restriction fragments containing the cpe gene were cloned and sequenced from two type C isolates and one type D isolate. The obtained cpe locus sequences were then used to construct an overlapping PCR assay to assess cpe locus diversity amongst other cpe-positive type C and D isolates. All seven surveyed cpe-positive type C isolates had a plasmid-borne cpe locus partially resembling the cpe locus of type A isolates carrying a chromosomal cpe gene. In contrast, all eight type D isolates shared the same plasmid-borne cpe locus, which differed substantially from the cpe locus present in other C. perfringens by containing two copies of an ORF with 67% identity to a transposase gene (COG4644 found in Tn1546, but not previously associated with the cpe gene. These results identify greater diversity amongst cpe locus organization than previously appreciated, providing new insights into cpe locus evolution. Finally, evidence for cpe gene mobilization was found for both type C and D isolates, which could explain their cpe plasmid diversity.

  9. Genetic characterization of glycopeptide-resistant enterococci of human and animal origin from mixed pig and poultry farms

    DEFF Research Database (Denmark)

    Jensen, Lars Bogø; Willems, R.J.L.; Van den Bogaard, A.E.

    2003-01-01

    Glycopeptide resistant enterococci (GRE) isolated from animals and humans were characterised using both AFPL typing and genetic characterisation of the glycopeptide resistance transposon Tn1546. All isolates were collected in 1997 when the glycopeptide avoparcin was still being used as growth...... promoter. All investigated animal isolates were from mixed pig and poultry farms in the Netherlands and the human isolated from the farmers of these farms. A total of 24 isolates were investigated. AFLP and Tn1546 typing revealed that both pig and poultry related enterococcal and vanA transposon genotypes...

  10. Interference enhanced thermoelectricity in quinoid type structures.

    Science.gov (United States)

    Strange, M; Seldenthuis, J S; Verzijl, C J O; Thijssen, J M; Solomon, G C

    2015-02-28

    Quantum interference (QI) effects in molecular junctions may be used to obtain large thermoelectric responses. We study the electrical conductance G and the thermoelectric response of a series of molecules featuring a quinoid core using density functional theory, as well as a semi-empirical interacting model Hamiltonian describing the π-system of the molecule which we treat in the GW approximation. Molecules with a quinoid type structure are shown to have two distinct destructive QI features close to the frontier orbital energies. These manifest themselves as two dips in the transmission, that remain separated, even when either electron donating or withdrawing side groups are added. We find that the position of the dips in the transmission and the frontier molecular levels can be chemically controlled by varying the electron donating or withdrawing character of the side groups as well as the conjugation length inside the molecule. This feature results in a very high thermoelectric power factor S(2)G and figure of merit ZT, where S is the Seebeck coefficient, making quinoid type molecules potential candidates for efficient thermoelectric devices.

  11. Comprehensive risk analysis for structure type selection.

    Science.gov (United States)

    2010-04-01

    Optimization of bridge selection and design traditionally has been sought in terms of the finished structure. This study presents a : more comprehensive risk-based analysis that includes user costs and accidents during the construction phase. Costs f...

  12. Structured personal care of type 2 diabetes

    DEFF Research Database (Denmark)

    Hansen, L J; Siersma, Volkert Dirk; Beck-Nielsen, Henning

    2013-01-01

    This study is a 19 year observational follow-up of a pragmatic open multicentre cluster-randomised controlled trial of 6 years of structured personal diabetes care starting from diagnosis.......This study is a 19 year observational follow-up of a pragmatic open multicentre cluster-randomised controlled trial of 6 years of structured personal diabetes care starting from diagnosis....

  13. Types and Functions of Coastal Structures

    DEFF Research Database (Denmark)

    Burcharth, H. F.; A. Hughes, Steven

    2003-01-01

    Coastal structures are used in coastal defence schemes with the objective of preventing shoreline erosion and flooding of the hinterland. Other objectives include sheltering of harbour basins and harbour entrances against waves, stabilization of navigation channels at inlets, and protection of wa...

  14. Host range of enterococcal vanA plasmids among Gram-positive intestinal bacteria

    DEFF Research Database (Denmark)

    Werner, Guido; Freitas, Ana R.; Coque, Teresa M.

    2010-01-01

    OBJECTIVES: The most prevalent type of acquired glycopeptide resistance is encoded by the vanA transposon Tn1546 located mainly on transferable plasmids in Enterococcus faecium. The limited occurrence in other species could be due to the lack of inter-species transferability and/or stability of T...

  15. Transposon characterization of vancomycin-resistant Enterococcus faecium (VREF) and dissemination of resistance associated with transferable plasmids

    DEFF Research Database (Denmark)

    Migura, Lourdes Garcia; Liebana, Ernesto; Jensen, Lars Bogø

    2007-01-01

    of the resistance. Methods and results: One hundred and one vancomycin-resistant Enterococcus faecium isolated from 19 unrelated farms have been investigated. Tn 1546 characterization by long PCR and Clal-digestions of amplicons showed a very low diversity of Tn types (n = 4) in comparison to the high genotypic...

  16. Factor structure of English-language personality type-nouns.

    Science.gov (United States)

    Saucier, Gerard

    2003-10-01

    Although type-nouns (e.g., idiot, hero) are important in person description, lexical studies of personality have concentrated on adjectives. This study tested structural hypotheses using 372 highly familiar English-language type-nouns and descriptions by 607 participants of either themselves, a liked, or a disliked target person. One- and 2-factor structures were most robust, and replicated similar structures found in previous adjectival studies. Additionally, the structure with 8 orthogonal factors had good replicability and applicability within single-gender subsamples; as in previous studies of type-nouns, it included factors corresponding directly to Extraversion and Intellect/Openness, but also to Attractiveness and Masculinity (or Ruggedness). The Big Five was only weakly replicated. Personality taxonomies based on adjectives are unlikely to be comprehensive, because type-nouns have different content emphases.

  17. Categorical structures for type theory in univalent foundations

    OpenAIRE

    Ahrens, Benedikt; Lumsdaine, Peter LeFanu; Voevodsky, Vladimir

    2017-01-01

    International audience; In this paper, we analyze and compare three of the many algebraic structures that have been used for modeling dependent type theories: categories with families, split type-categories, and representable maps of presheaves. We study these in the setting of univalent foundations, where the relationships between them can be stated more transparently. Specifically, we construct maps between the different structures and show that these maps are equivalences under suitable as...

  18. Types of Structural Unemployment in the United Kingdom.

    Science.gov (United States)

    Hart, Peter E.

    1990-01-01

    Assesses the extent of the following types of structural unemployment in the United Kingdom: technological change, skills mismatch, geographical mismatch, demographic shifts, institutional rigidity, unemployability, and capital restructuring. Concludes that measurement is difficult and the types create segmented labor markets that obstruct the…

  19. PROVIDING SERVICEABILITY OF STRUCTURAL BEARING TYPES FOR ROADWAY BRIDGES

    Directory of Open Access Journals (Sweden)

    R. I. Polyuga

    2010-03-01

    Full Text Available In the article the description of structural bearing types for roadway bridges and their classification is given. Special attention is paid to effective bearings with elastomeric materials – rubber, pot, spherical ones. Characteristic defects of structural bearings and demands of serviceability are noticed.

  20. Polyclonal emergence of vanA vancomycin-resistant Enterococcus faecium in Australia.

    Science.gov (United States)

    van Hal, Sebastiaan J; Espedido, Björn A; Coombs, Geoffrey W; Howden, Benjamin P; Korman, Tony M; Nimmo, Graeme R; Gosbell, Iain B; Jensen, Slade O

    2017-04-01

    To investigate the genetic context associated with the emergence of vanA VRE in Australia. The whole genomes of 18 randomly selected vanA -positive Enterococcus faecium patient isolates, collected between 2011 and 2013 from hospitals in four Australian capitals, were sequenced and analysed. In silico typing and transposon/plasmid assembly revealed that the sequenced isolates represented (in most cases) different hospital-adapted STs and were associated with a variety of different Tn 1546 variants and plasmid backbone structures. The recent emergence of vanA VRE in Australia was polyclonal and not associated with the dissemination of a single 'dominant' ST or vanA -encoding plasmid. Interestingly, the factors contributing to this epidemiological change are not known and future studies may need to consider investigation of potential community sources.

  1. A Quasi-Type-1 Phase-Locked Loop Structure

    DEFF Research Database (Denmark)

    Golestan, Saeed; Fernandez, Francisco Daniel Freijedo; Vidal, Ana

    2014-01-01

    The grid voltage phase and frequency are crucial information in control of most grid connected power electronic based equipment. Most often, a phase-locked loop (PLL) is employed for this purpose. A PLL is a closed-loop feedback control system that the phase of its output signal is related......-error in the presence of frequency drifts. To overcome this drawback of type-1 PLLs, and at the same time, to achieve a fast dynamic response and high filtering capability, a modified PLL structure is proposed in this letter. The proposed PLL has a similar structure to a type-1 PLL, but from the control point of view...... is a type-2 control system. For this reason, it is called the quasi-type-1 PLL (QT1-PLL). The effectiveness of the proposed PLL is confirmed through simulation and experimental results and comparison with standard PLLs....

  2. Structural-communicative types of the perplexed echo question

    OpenAIRE

    VOROBYOVA ELENA N.

    2015-01-01

    Modern linguistics has shown us that the language is not limited to questions with the standard semantics of interrogation. Among the interrogative sentences used in the secondary functions one can find inquiries with additional emotional colourings. Perplexity is the closest emotional evaluative meaning, accompanying the interrogative semantics of a question. In the paper, one of the structural-communicative types of the perplexed question (an echo question) is considered. Two structural typ...

  3. Left ventricular structure and function in black normotensive type 2 ...

    African Journals Online (AJOL)

    Patients' age, body weight, duration of DM, LV mass index and left atrial dimension were positive correlates of LVDD while patients' age, weight and left atrial dimension were independent predictors of LVDD. Conclusion: There is high prevalence of alterations in LV structure and function in normotensive type 2 DM; and ...

  4. Structural characterization of thyroglobulin type-1 domains of equistatin

    NARCIS (Netherlands)

    Galesa, K.; Pain, R.; Jongsma, M.A.; Turk, V.; Lenarci, B.

    2003-01-01

    Equistatin is a protein composed of three thyroglobulin type-1 domains. It inhibits papain-like cysteine proteinases and the aspartic proteinase, cathepsin D. To determine the structural basis for this inhibition we cloned and expressed the separated domains (eq d-1, eq d-2, eq d-3) in Pichia

  5. Effect of Different Structure Type Traffic On Railway Line Capacity

    Directory of Open Access Journals (Sweden)

    Gleba Radosław

    2017-04-01

    Full Text Available The article points to methods of analyzing railway traffic conditions based on two parameters: capacity and delay of trains. The impact of the differentiated railway type structure on the capacity of the railway line was presented. Particular attention has been paid to the assessment of commonly used simplifications in analyzes.

  6. First diastereoselective construction of butane-type and butyrolactone-type secocyclolignane structures.

    Science.gov (United States)

    Morita, Masao; Yamauchi, Satoshi

    2009-11-01

    The first diastereoselective construction of butane-type and butyrolactone-type secocyclolignanes was achieved by the application of a high-valency heterobimetallic Ir-Sn complex to benzyl alcohols prepared from an Evans's anti-aldol product. The elimination of an acetoxymethyl group to give a cinnamyl structure by using a high-valency heterobimetallic Ir-Sn complex was also observed in this study.

  7. Atomic Structure of Type VI Contractile Sheath from Pseudomonas aeruginosa.

    Science.gov (United States)

    Salih, Osman; He, Shaoda; Planamente, Sara; Stach, Lasse; MacDonald, James T; Manoli, Eleni; Scheres, Sjors H W; Filloux, Alain; Freemont, Paul S

    2017-12-21

    Pseudomonas aeruginosa has three type VI secretion systems (T6SSs), H1-, H2-, and H3-T6SS, each belonging to a distinct group. The two T6SS components, TssB/VipA and TssC/VipB, assemble to form tubules that conserve structural/functional homology with tail sheaths of contractile bacteriophages and pyocins. Here, we used cryoelectron microscopy to solve the structure of the H1-T6SS P. aeruginosa TssB1C1 sheath at 3.3 Å resolution. Our structure allowed us to resolve some features of the T6SS sheath that were not resolved in the Vibrio cholerae VipAB and Francisella tularensis IglAB structures. Comparison with sheath structures from other contractile machines, including T4 phage and R-type pyocins, provides a better understanding of how these systems have conserved similar functions/mechanisms despite evolution. We used the P. aeruginosa R2 pyocin as a structural template to build an atomic model of the TssB1C1 sheath in its extended conformation, allowing us to propose a coiled-spring-like mechanism for T6SS sheath contraction. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  8. Magnetic mirror structure for testing shell-type quadrupole coils

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, N.; Barzi, E.; Bossert, R.; Chlachidze, G.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Nobrega, F.; Novitski, I.; Tartaglia, N.; Turrioni, D.; /Fermilab

    2009-10-01

    This paper presents magnetic and mechanical designs and analyses of the quadrupole mirror structure to test single shell-type quadrupole coils. Several quadrupole coils made of different Nb{sub 3}Sn strands, cable insulation and pole materials were tested using this structure at 4.5 and 1.9 K. The coils were instrumented with voltage taps, spot heaters, temperature sensors and strain gauges to study their mechanical and thermal properties and quench performance. The results of the quadrupole mirror model assembly and test are reported and discussed.

  9. Structural and functional salivary disorders in type 2 diabetic patients

    OpenAIRE

    Carda Batalla, María del Carmen; Mosquera Lloreda, Nezly; Salom, Lucas; Gómez de Ferraris, María Elsa; Peydró Olaya, Amando

    2006-01-01

    Diabetes mellitus type 2 is the most common metabolic disorder and it causes an important morbimortality. The structural modifications in the parotid gland (sialosis) had already been described in these patients and could result in variations in the salivary composition, as well as an increase in periodontal and dental pathology. Objectives: to compare the biochemical findings in the saliva and to correlate these biochemical disturbances with the morphologic findings previously described....

  10. Structure of a Kunitz-type potato cathepsin D inhibitor

    Czech Academy of Sciences Publication Activity Database

    Guo, J.; Erskine, P. T.; Coker, A. R.; Wood, S. P.; Cooper, J. B.; Mareš, Michael; Baudyš, Miroslav

    2015-01-01

    Roč. 192, č. 3 (2015), s. 554-560 ISSN 1047-8477 R&D Projects: GA ČR GA15-18929S; GA MŠk LO1302 Institutional support: RVO:61388963 Keywords : potato cathepsin D inhibitor * Kunitz-type protease inhibitor * protein X-ray structure * reactive-site loop * docking Subject RIV: CE - Biochemistry Impact factor: 2.570, year: 2015

  11. Sound radiation characteristics of a box-type structure

    Science.gov (United States)

    Ran Lin, Tian; Pan, Jie

    2009-09-01

    The finite element and boundary element methods are employed in this study to investigate the sound radiation characteristics of a box-type structure. It has been shown [T.R. Lin, J. Pan, Vibration characteristics of a box-type structure, Journal of Vibration and Acoustics, Transactions of ASME 131 (2009) 031004-1-031004-9] that modes of natural vibration of a box-type structure can be classified into six groups according to the symmetry properties of the three panel pairs forming the box. In this paper, we demonstrate that such properties also reveal information about sound radiation effectiveness of each group of modes. The changes of radiation efficiencies and directivity patterns with the wavenumber ratio (the ratio between the acoustic and the plate bending wavenumbers) are examined for typical modes from each group. Similar characteristics of modal radiation efficiencies between a box structure and a corresponding simply supported panel are observed. The change of sound radiation patterns as a function of the wavenumber ratio is also illustrated. It is found that the sound radiation directivity of each box mode can be correlated to that of elementary sound sources (monopole, dipole, etc.) at frequencies well below the critical frequency of the plates of the box. The sound radiation pattern on the box surface also closely related to the vibration amplitude distribution of the box structure at frequencies above the critical frequency. In the medium frequency range, the radiated sound field is dominated by the edge vibration pattern of the box. The radiation efficiency of all box modes reaches a peak at frequencies above the critical frequency, and gradually approaches unity at higher frequencies.

  12. Three-dimensional structure of a mouse-adapted type 2/type 1 poliovirus chimera.

    Science.gov (United States)

    Yeates, T O; Jacobson, D H; Martin, A; Wychowski, C; Girard, M; Filman, D J; Hogle, J M

    1991-01-01

    The crystal structure of V510, a chimeric type 2/type 1 poliovirus, has been determined at 2.6 A resolution. Unlike the parental Mahoney strain of type 1 poliovirus, V510 is able to replicate in the mouse central nervous system, due entirely to the replacement of six amino acids in the exposed BC loop of capsid protein VP1. Significant structural differences between the two strains cluster in a major antigenic site of the virus, located at the apex of the radial projection which surrounds the viral five-fold axis. Residues implicated in the mouse-virulence of poliovirus by genetic studies are located in this area, and include the residues which are responsible for stabilizing the conformation of the BC loop in V510. Despite evidence that this area is not involved in receptor binding in cultured primate cells, the genetic and structural observations suggest that this area plays a critical role in receptor interactions in the mouse central nervous system. These results provide a structural framework for further investigation of the molecular determinants of host and tissue tropism in viruses. Images PMID:1651227

  13. Predicting aphasia type from brain damage measured with structural MRI.

    Science.gov (United States)

    Yourganov, Grigori; Smith, Kimberly G; Fridriksson, Julius; Rorden, Chris

    2015-12-01

    Chronic aphasia is a common consequence of a left-hemisphere stroke. Since the early insights by Broca and Wernicke, studying the relationship between the loci of cortical damage and patterns of language impairment has been one of the concerns of aphasiology. We utilized multivariate classification in a cross-validation framework to predict the type of chronic aphasia from the spatial pattern of brain damage. Our sample consisted of 98 patients with five types of aphasia (Broca's, Wernicke's, global, conduction, and anomic), classified based on scores on the Western Aphasia Battery (WAB). Binary lesion maps were obtained from structural MRI scans (obtained at least 6 months poststroke, and within 2 days of behavioural assessment); after spatial normalization, the lesions were parcellated into a disjoint set of brain areas. The proportion of damage to the brain areas was used to classify patients' aphasia type. To create this parcellation, we relied on five brain atlases; our classifier (support vector machine - SVM) could differentiate between different kinds of aphasia using any of the five parcellations. In our sample, the best classification accuracy was obtained when using a novel parcellation that combined two previously published brain atlases, with the first atlas providing the segmentation of grey matter, and the second atlas used to segment the white matter. For each aphasia type, we computed the relative importance of different brain areas for distinguishing it from other aphasia types; our findings were consistent with previously published reports of lesion locations implicated in different types of aphasia. Overall, our results revealed that automated multivariate classification could distinguish between aphasia types based on damage to atlas-defined brain areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. PREDICTING APHASIA TYPE FROM BRAIN DAMAGE MEASURED WITH STRUCTURAL MRI

    Science.gov (United States)

    Yourganov, Grigori; Smith, Kimberly G.; Fridriksson, Julius; Rorden, Chris

    2015-01-01

    Chronic aphasia is a common consequence of a left-hemisphere stroke. Since the early insights by Broca and Wernicke, studying the relationship between the loci of cortical damage and patterns of language impairment has been one of the concerns of aphasiology. We utilized multivariate classification in a cross-validation framework to predict the type of chronic aphasia from the spatial pattern of brain damage. Our sample consisted of 98 patients with five types of aphasia (Broca’s, Wernicke’s, global, conduction, and anomic), classified based on scores on the Western Aphasia Battery. Binary lesion maps were obtained from structural MRI scans (obtained at least 6 months poststroke, and within 2 days of behavioural assessment); after spatial normalization, the lesions were parcellated into a disjoint set of brain areas. The proportion of damage to the brain areas was used to classify patients’ aphasia type. To create this parcellation, we relied on five brain atlases; our classifier (support vector machine) could differentiate between different kinds of aphasia using any of the five parcellations. In our sample, the best classification accuracy was obtained when using a novel parcellation that combined two previously published brain atlases, with the first atlas providing the segmentation of grey matter, and the second atlas used to segment the white matter. For each aphasia type, we computed the relative importance of different brain areas for distinguishing it from other aphasia types; our findings were consistent with previously published reports of lesion locations implicated in different types of aphasia. Overall, our results revealed that automated multivariate classification could distinguish between aphasia types based on damage to atlas-defined brain areas. PMID:26465238

  15. Structure and biophysics of type III secretion in bacteria.

    Science.gov (United States)

    Chatterjee, Srirupa; Chaudhury, Sukanya; McShan, Andrew C; Kaur, Kawaljit; De Guzman, Roberto N

    2013-04-16

    Many plant and animal bacterial pathogens assemble a needle-like nanomachine, the type III secretion system (T3SS), to inject virulence proteins directly into eukaryotic cells to initiate infection. The ability of bacteria to inject effectors into host cells is essential for infection, survival, and pathogenesis for many Gram-negative bacteria, including Salmonella, Escherichia, Shigella, Yersinia, Pseudomonas, and Chlamydia spp. These pathogens are responsible for a wide variety of diseases, such as typhoid fever, large-scale food-borne illnesses, dysentery, bubonic plague, secondary hospital infections, and sexually transmitted diseases. The T3SS consists of structural and nonstructural proteins. The structural proteins assemble the needle apparatus, which consists of a membrane-embedded basal structure, an external needle that protrudes from the bacterial surface, and a tip complex that caps the needle. Upon host cell contact, a translocon is assembled between the needle tip complex and the host cell, serving as a gateway for translocation of effector proteins by creating a pore in the host cell membrane. Following delivery into the host cytoplasm, effectors initiate and maintain infection by manipulating host cell biology, such as cell signaling, secretory trafficking, cytoskeletal dynamics, and the inflammatory response. Finally, chaperones serve as regulators of secretion by sequestering effectors and some structural proteins within the bacterial cytoplasm. This review will focus on the latest developments and future challenges concerning the structure and biophysics of the needle apparatus.

  16. Structural and functional salivary disorders in type 2 diabetic patients.

    Science.gov (United States)

    Carda, Carmen; Mosquera-Lloreda, Nezly; Salom, Lucas; Gomez de Ferraris, Maria Elsa; Peydró, Amando

    2006-07-01

    Diabetes mellitus type 2 is the most common metabolic disorder and it causes an important morbimortality. The structural modifications in the parotid gland (sialosis) had already been described in these patients and could result in variations in the salivary composition, as well as an increase in periodontal and dental pathology. To compare the biochemical findings in the saliva and to correlate these biochemical disturbances with the morphologic findings previously described. Clinical information were gathered about 33 patients, 17 had type 2 diabetes. Samples of whole saliva were obtained for biochemical analysis and serum samples to determine metabolic control. In the diabetics saliva we found urea and total proteins increased and reduced levels of microalbumina. Salivary glucose was only augmented in patients with poor metabolic control. Clinical symptoms of xerostomia were present in 76,4% and dental and periodontal disease in 100%. The parotid gland was characterised by the presence of small acini, lipid intracytoplasmic droplets, as well as adipose stroma infiltration. The acinar cytoqueratins expression was heterogeneous and very positive in the hyperplasic ducts. These biochemical disorders in the saliva of the type 2 diabetic patients would be related with the structural changes previously observed in parotid glands.

  17. The Structure of Carbon Detonation in Type Ia Supernovae

    Science.gov (United States)

    Fryxell, B.; Timmes, F. X.; Zingale, M.; Dursi, L. J.; Ricker, P.; Olson, K.; Calder, A. C.; Tufo, H.; Truran, J. W.; Rosner, R.; MacNeice, P.

    2000-12-01

    Type Ia Supernova explosions are thought to begin as deflagrations in the center of accreting white dwarfs. Observations suggest that at some point, the burning undergoes a transition from a deflagration to a detonation front. We describe high-resolution three-dimensional simulations of the structure of such a detonation. The pre-detonation material is assumed to be pure C12 at a density of 107 g cm-3. A cellular structure develops behind the front, leaving pockets of unburned fuel. The cellular instability is unlikely to have any observational consequences at this density, since the cell size is only a few centimeters. However, as the detonation approaches the surface, the cell size will become comparable to the radius of the star, leaving a nonspherical distribution of reaction products and modifying the spectral signature of the explosion. The calculations were performed on 1000 processors of ASCI Blue Pacific at Lawrence Livermore National Laboratory using the Flash Code developed at the Center for Astrophysical Thermonuclear Flashes at the University of Chicago. They represent by far the largest simulations ever carried out on the detailed structure of burning fronts in Type Ia supernovae. This work was supported in part by the Department of Energy Grant No. B341495 to the Center for Astrophysical Thermonuclear Flashes at the University of Chicago under the ASCI Strategic Alliances Program and by NASA/Goddard Space Flight Center.

  18. Structure- and oil type-based efficacy of emulsion adjuvants.

    Science.gov (United States)

    Jansen, Theo; Hofmans, Marij P M; Theelen, Marc J G; Manders, Frans; Schijns, Virgil E J C

    2006-06-29

    Oil-based emulsions are well-known immunopotentiators for inactivated, "killed" vaccines. We addressed the relationship between emulsion structure and levels of in vivo antibody formation to inactivated New Castle Disease virus (NDV) and Infectious Bronchitis virus (IBV) as antigens in 3-week-old chickens. The use of a polymeric emulsifier allowed for direct comparison of three types of emulsions, water-in-oil (W/O), oil-in-water (O/W) and W/O-in-water (W/O/W), while maintaining an identical content of components for each vehicle. They were prepared with either non-metabolizable, mineral oil or metabolizable, Miglyol 840. In addition, we assessed the inherent release capacity of each emulsion variant in vitro. Remarkably, we noted that W/O-type emulsions induced the best immune responses, while they released no antigen during 3 weeks. In general, mineral oil vaccines showed superior efficacy compared to Miglyol 840-based vaccines.

  19. Types of architectural structures and the use of smart materials

    Science.gov (United States)

    Tavşan, Cengiz; Sipahi, Serkan

    2017-07-01

    about smart materials; the second discusses the types and characteristics of smart materials over the tables detailing their utilization and functions in the structures included in the set of examples. The final section of the study, on the other hand, elaborates on the findings, discussing them with reference to the types of structures.

  20. Microbial mat ecosystems: Structure types, functional diversity, and biotechnological application

    Directory of Open Access Journals (Sweden)

    Cristina M. Prieto-Barajas

    2018-01-01

    Full Text Available Microbial mats are horizontally stratified microbial communities, exhibiting a structure defined by physiochemical gradients, which models microbial diversity, physiological activities, and their dynamics as a whole system. These ecosystems are commonly associated with aquatic habitats, including hot springs, hypersaline ponds, and intertidal coastal zones and oligotrophic environments, all of them harbour phototrophic mats and other environments such as acidic hot springs or acid mine drainage harbour non-photosynthetic mats. This review analyses the complex structure, diversity, and interactions between the microorganisms that form the framework of different types of microbial mats located around the globe. Furthermore, the many tools that allow studying microbial mats in depth and their potential biotechnological applications are discussed.

  1. Vulnerability Assessment for Various Types of Cloud Structures

    Directory of Open Access Journals (Sweden)

    Anatoly Valerievich Tsaregorodtsev

    2014-12-01

    Full Text Available Today organizations increasingly consider cloud computing as an alternative way of using information technology. At the same time, the use of different vulnerabilities of infrastructure components, network services and applications remains are the major threat to the cloud. The article proposes a methodology for vulnerability assessment for any type of cloud structures, which will allow to determine the coefficient of counter to possible attacks and to correlate the amount of damage to the total cost of ownership of organization IT-infrastructure.

  2. Impact of type 2 diabetes and duration of type 2 diabetes on cardiac structure and function

    DEFF Research Database (Denmark)

    Jørgensen, Peter G; Jensen, Magnus T; Mogelvang, Rasmus

    2016-01-01

    BACKGROUND: Contemporary treatment of type 2 diabetes (T2D) has improved patient outcome and may also have affected myocardial structure and function. We aimed to describe the effect of T2D and T2D duration on cardiac structure and function in a large outpatient population. METHODS: We performed...... dysfunction persisted after multivariable adjustment (P=0.013). CONCLUSIONS: In patients with T2D, LV structural and functional alterations persist and are accentuated with increasing diabetes duration despite reductions in overall risk of cardiovascular disease in this patient population....... comprehensive echocardiography on a representative sample of 1004 persons including a representative sample of 770 patients with T2D without known heart disease and 234 age- and sex-matched controls. RESULTS: T2D was associated with increased left ventricular (LV) wall thicknesses and decreased LV internal...

  3. Crystal structure of human quinone reductase type 2, a metalloflavoprotein.

    Science.gov (United States)

    Foster, C E; Bianchet, M A; Talalay, P; Zhao, Q; Amzel, L M

    1999-08-03

    In mammals, two separate but homologous cytosolic quinone reductases have been identified: NAD(P)H:quinone oxidoreductase type 1 (QR1) (EC 1.6.99.2) and quinone reductase type 2 (QR2). Although QR1 and QR2 are nearly 50% identical in protein sequence, they display markedly different catalytic properties and substrate specificities. We report here two crystal structures of QR2: in its native form and bound to menadione (vitamin K(3)), a physiological substrate. Phases were obtained by molecular replacement, using our previously determined rat QR1 structure as the search model. QR2 shares the overall fold of the major catalytic domain of QR1, but lacks the smaller C-terminal domain. The FAD binding sites of QR1 and QR2 are very similar, but their hydride donor binding sites are considerably different. Unexpectedly, we found that QR2 contains a specific metal binding site, which is not present in QR1. Two histidine nitrogens, one cysteine thiol, and a main chain carbonyl group are involved in metal coordination. The metal binding site is solvent-accessible, and is separated from the FAD cofactor by a distance of about 13 A.

  4. Types of marriages, population structure and genetic disease.

    Science.gov (United States)

    Machado, T M B; Bomfim, T F; Souza, L V; Soares, N; Santos, F L; Acosta, A X; Abe-Sandes, K

    2013-07-01

    A high occurrence rate of consanguineous marriages may favour the onset and increased frequency of autosomal recessive diseases in a population. The population of Monte Santo, Bahia, Brazil, has a high frequency of rare genetic diseases such as mucopolysaccharidosis type VI, whose observed frequency in this population is 1:5000, while the incidence of this disease recorded in other regions of the world varies from 1:43,261 in Turkey to 1:1,505,160 in Switzerland. To verify the influence of consanguineous marriage on the increased frequency of observed genetic diseases in this population, the population structure and frequency of different types of marriage during different time periods were evaluated. A total of 9765 marriages were found in an analysis of parish marriage records from the city. Over three periods, 1860-1895, 1950-1961 and 1975-2010, the inbreeding rates were 37.1%, 13.2% and 4.2% respectively. Although there was a high rate of inbreeding, endogamic marriages were the dominant marriage type in all three periods. In the most recent period, there was an increase in the number of exogamous marriages and those among immigrants, but most of these occurred among individuals from cities that neighbour Monte Santo. The low rate of migration and high frequency of endogamic and consanguineous marriages show that growth of this population is predominantly internal and could explain the occurrence, and increase in frequency, of recessive genetic diseases in the city.

  5. Structural Health Monitoring for a Z-Type Special Vehicle.

    Science.gov (United States)

    Yuan, Chaolin; Ren, Liang; Li, Hongnan

    2017-06-01

    Nowadays there exist various kinds of special vehicles designed for some purposes, which are different from regular vehicles in overall dimension and design. In that case, accidents such as overturning will lead to large economical loss and casualties. There are still no technical specifications to follow to ensure the safe operation and driving of these special vehicles. Owing to the poor efficiency of regular maintenance, it is more feasible and effective to apply real-time monitoring during the operation and driving process. In this paper, the fiber Bragg grating (FBG) sensors are used to monitor the safety of a z-type special vehicle. Based on the structural features and force distribution, a reasonable structural health monitoring (SHM) scheme is presented. Comparing the monitoring results with the finite element simulation results guarantees the accuracy and reliability of the monitoring results. Large amounts of data are collected during the operation and driving progress to evaluate the structural safety condition and provide reference for SHM systems developed for other special vehicles.

  6. Structural Health Monitoring for a Z-Type Special Vehicle

    Directory of Open Access Journals (Sweden)

    Chaolin Yuan

    2017-06-01

    Full Text Available Nowadays there exist various kinds of special vehicles designed for some purposes, which are different from regular vehicles in overall dimension and design. In that case, accidents such as overturning will lead to large economical loss and casualties. There are still no technical specifications to follow to ensure the safe operation and driving of these special vehicles. Owing to the poor efficiency of regular maintenance, it is more feasible and effective to apply real-time monitoring during the operation and driving process. In this paper, the fiber Bragg grating (FBG sensors are used to monitor the safety of a z-type special vehicle. Based on the structural features and force distribution, a reasonable structural health monitoring (SHM scheme is presented. Comparing the monitoring results with the finite element simulation results guarantees the accuracy and reliability of the monitoring results. Large amounts of data are collected during the operation and driving progress to evaluate the structural safety condition and provide reference for SHM systems developed for other special vehicles.

  7. Structure of a Type-1 Secretion System ABC Transporter.

    Science.gov (United States)

    Morgan, Jacob L W; Acheson, Justin F; Zimmer, Jochen

    2017-03-07

    Type-1 secretion systems (T1SSs) represent a widespread mode of protein secretion across the cell envelope in Gram-negative bacteria. The T1SS is composed of an inner-membrane ABC transporter, a periplasmic membrane-fusion protein, and an outer-membrane porin. These three components assemble into a complex spanning both membranes and providing a conduit for the translocation of unfolded polypeptides. We show that ATP hydrolysis and assembly of the entire T1SS complex is necessary for protein secretion. Furthermore, we present a 3.15-Å crystal structure of AaPrtD, the ABC transporter found in the Aquifex aeolicus T1SS. The structure suggests a substrate entry window just above the transporter's nucleotide binding domains. In addition, highly kinked transmembrane helices, which frame a narrow channel not observed in canonical peptide transporters, are likely involved in substrate translocation. Overall, the AaPrtD structure supports a polypeptide transport mechanism distinct from alternating access. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Thermodynamic and structural characterization of amphiphilic melamine-type monolayers.

    Science.gov (United States)

    Vollhardt, D; Fainerman, V B; Liu, F

    2005-06-16

    Monolayers of amphiphilic melamine derivatives are good candidates for the formation of supramolecular structures by hydrogen-bonding of nonsurface active species dissolved in the aqueous subphase by molecular recognition. In the present work, the thermodynamic and structural properties of the Langmuir monolayers of a homologous series of a selected amphiphilic melamine-type are characterized. Good candidates for such studies are the decyl, undecyl, and dodecyl homologues of the 2,4-di(n-alkylamino)-6-amino-1,3,5-triazine (2CnH(2n+1)-melamine) monolayers because of their two-phase coexistence region in the accessible temperature range. The characterization of the structural and phase behavior is performed by a combination of surface pressure studies with Brewster angle microscopy (BAM) imaging and Grazing incidence X-ray diffraction (GIXD) measurements. A comprehensive thermodynamic analysis provides good agreement between the experimental surface pressure - area (Pi-A) isotherms and the theoretical curves that were calculated on the basis of equations of state for a large region of monolayer stages developed by us in J. Phys. Chem. 1999, 103, 145. Theoretical curves calculated by application of equations of state only for the fluid monolayer state proposed recently by Rusanov (J. Chem Phys. 2004, 120, 10736) are in good agreement with the experiments in a limited temperature range. A rigorous equation is derived and applied to the experimental results for the calculation of the enthalpy of two-dimensional phase transition. The combination of BAM and GIXD illustrates that the microscopic long range ordering of the condensed monolayer phases is related to the lattice structure of the condensed monolayer.

  9. Structural Characterization of Novel Pseudomonas aeruginosa Type IV Pilins

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Y.; Jackson, S; Aidoo, F; Junop, M; Burrows, L

    2010-01-01

    Pseudomonas aeruginosa type IV pili, composed of PilA subunits, are used for attachment and twitching motility on surfaces. P. aeruginosa strains express one of five phylogenetically distinct PilA proteins, four of which are associated with accessory proteins that are involved either in pilin posttranslational modification or in modulation of pilus retraction dynamics. Full understanding of pilin diversity is crucial for the development of a broadly protective pilus-based vaccine. Here, we report the 1.6-{angstrom} X-ray crystal structure of an N-terminally truncated form of the novel PilA from strain Pa110594 (group V), which represents the first non-group II pilin structure solved. Although it maintains the typical T4a pilin fold, with a long N-terminal {alpha}-helix and four-stranded antiparallel {beta}-sheet connected to the C-terminus by a disulfide-bonded loop, the presence of an extra helix in the {alpha}{beta}-loop and a disulfide-bonded loop with helical character gives the structure T4b pilin characteristics. Despite the presence of T4b features, the structure of PilA from strain Pa110594 is most similar to the Neisseria gonorrhoeae pilin and is also predicted to assemble into a fiber similar to the GC pilus, based on our comparative pilus modeling. Interactions between surface-exposed areas of the pilin are suggested to contribute to pilus fiber stability. The non-synonymous sequence changes between group III and V pilins are clustered in the same surface-exposed areas, possibly having an effect on accessory protein interactions. However, based on our high-confidence model of group III PilA{sub PA14}, compensatory changes allow for maintenance of a similar shape.

  10. How Neighborhood Poverty Structures Types and Levels of Social Integration.

    Science.gov (United States)

    Marcus, Andrea Fleisch; Echeverria, Sandra E; Holland, Bart K; Abraido-Lanza, Ana F; Passannante, Marian R

    2015-09-01

    Social integration is fundamental to health and well-being. However, few studies have explored how neighborhood contexts pattern types and levels of social integration that individuals experience. We examined how neighborhood poverty structures two dimensions of social integration: integration with neighbors and social integration more generally. Using data from the United States Third National Health and Nutrition Examination Survey, we linked study participants to percent poverty in their neighborhood of residence (N = 16,040). Social integration was assessed using a modified Social Network Index and neighborhood integration based on yearly visits with neighbors. We fit multivariate logistic regression models that accounted for the complex survey design. Living in high poverty neighborhoods was associated with lower social integration but higher visits with neighbors. Neighborhood poverty distinctly patterns social integration, demonstrating that contexts shape the extent and quality of social relationships.

  11. Perovskite-type oxides - Oxygen electrocatalysis and bulk structure

    Science.gov (United States)

    Carbonio, R. E.; Fierro, C.; Tryk, D.; Scherson, D.; Yeager, E.

    1988-01-01

    Perovskite type oxides were considered for use as oxygen reduction and generation electrocatalysts in alkaline electrolytes. Perovskite stability and electrocatalytic activity are studied along with possible relationships of the latter with the bulk solid state properties. A series of compounds of the type LaFe(x)Ni1(-x)O3 was used as a model system to gain information on the possible relationships between surface catalytic activity and bulk structure. Hydrogen peroxide decomposition rate constants were measured for these compounds. Ex situ Mossbauer effect spectroscopy (MES), and magnetic susceptibility measurements were used to study the solid state properties. X ray photoelectron spectroscopy (XPS) was used to examine the surface. MES has indicated the presence of a paramagnetic to magnetically ordered phase transition for values of x between 0.4 and 0.5. A correlation was found between the values of the MES isomer shift and the catalytic activity for peroxide decomposition. Thus, the catalytic activity can be correlated to the d-electron density for the transition metal cations.

  12. Type IIA orientifolds on SU(2)-structure manifolds

    Energy Technology Data Exchange (ETDEWEB)

    Danckaert, Thomas

    2010-11-15

    We investigate the possible supersymmetry-preserving orientifold projections of type IIA string theory on a six-dimensional background with SU(2)-structure. We find two categories of projections which preserve half of the low-energy supersymmetry, reducing the effective theory from an N=4 supergravity theory, to an N=2 supergravity. For these two cases, we impose the projection on the low-energy spectrum and reduce the effective N=4 supergravity action accordingly. We can identify the resulting gauged N=2 supergravity theory and bring the action into canonical form. We compute the scalar moduli spaces and characterize the gauged symmetries in terms of the geometry of these moduli spaces. Due to their origin in N=4 supergravity, which is a highly constrained theory, the moduli spaces are of a very simple form. We find that, for suitable background manifolds, isometries in all scalar sectors can become gauged. The obtained gaugings share many features with those of N=2 supergravities obtained previously from other G-structure compactifications. (orig.)

  13. Development, characteristics and comparative structural analysis of tensegrity type cable domes

    National Research Council Canada - National Science Library

    Nenadović Aleksandra

    2010-01-01

    Tensegrity type cable domes are three-dimensional structural configurations, prestressed inside the perimeter compression ring, in which the continuous tension throughout the roof structure is made...

  14. Clonal dissemination of VanA-type glycopeptide-resistant Enterococcus faecalis between hospitals of two cities located 100 km apart

    Directory of Open Access Journals (Sweden)

    M.L. Moretti

    2004-09-01

    Full Text Available Nosocomial dissemination of glycopeptide-resistant enterococci represents a major problem in hospitals worldwide. In Brazil, the dissemination among hospitals in the city of São Paulo of polyclonal DNA profiles was previously described for vancomycin-resistant Enterococcus faecium. We describe here the dissemination of VanA phenotype E. faecalis between two hospitals located in different cities in the State of São Paulo. The index outbreak occurred in a tertiary care university hospital (HCUSP in the city of São Paulo and three years later a cluster caused by the same strain was recognized in two patients hospitalized in a private tertiary care hospital (CMC located 100 km away in the interior of the state. From May to July 1999, 10 strains of vancomycin-resistant E. faecalis were isolated from 10 patients hospitalized in the HCUSP. The DNA genotyping using pulsed-field gel electrophoresis (PFGE showed that all isolates were originated from the same clone, suggesting nosocomial dissemination. From May to July 2002, three strains of vancomycin-resistant E. faecalis were isolated from two patients hospitalized in CMC and both patients were colonized by the vancomycin-resistant Enterococcus in skin lesions. All isolates from CMC and HCUSP were highly resistant to vancomycin and teicoplanin. The three strains from CMC had minimum inhibitory concentration >256 µg/ml for vancomycin, and 64 (CMC 1 and CMC 2 and 96 µg/ml (CMC 3 for teicoplanin, characterizing a profile of VanA resistance to glycopeptides. All strains had the presence of the transposon Tn1546 detected by PCR and were closely related when typed by PFGE. The dissemination of the E. faecalis VanA phenotype among hospitals located in different cities is of great concern because E. faecalis commonly colonizes the gastrointestinal tract of patients and healthy persons for periods varying from weeks to years, which, together with the persistence of vancomycin-resistant Enterococcus in

  15. Clonal dissemination of VanA-type glycopeptide-resistant Enterococcus faecalis between hospitals of two cities located 100 km apart

    Directory of Open Access Journals (Sweden)

    Moretti M.L.

    2004-01-01

    Full Text Available Nosocomial dissemination of glycopeptide-resistant enterococci represents a major problem in hospitals worldwide. In Brazil, the dissemination among hospitals in the city of São Paulo of polyclonal DNA profiles was previously described for vancomycin-resistant Enterococcus faecium. We describe here the dissemination of VanA phenotype E. faecalis between two hospitals located in different cities in the State of São Paulo. The index outbreak occurred in a tertiary care university hospital (HCUSP in the city of São Paulo and three years later a cluster caused by the same strain was recognized in two patients hospitalized in a private tertiary care hospital (CMC located 100 km away in the interior of the state. From May to July 1999, 10 strains of vancomycin-resistant E. faecalis were isolated from 10 patients hospitalized in the HCUSP. The DNA genotyping using pulsed-field gel electrophoresis (PFGE showed that all isolates were originated from the same clone, suggesting nosocomial dissemination. From May to July 2002, three strains of vancomycin-resistant E. faecalis were isolated from two patients hospitalized in CMC and both patients were colonized by the vancomycin-resistant Enterococcus in skin lesions. All isolates from CMC and HCUSP were highly resistant to vancomycin and teicoplanin. The three strains from CMC had minimum inhibitory concentration >256 µg/ml for vancomycin, and 64 (CMC 1 and CMC 2 and 96 µg/ml (CMC 3 for teicoplanin, characterizing a profile of VanA resistance to glycopeptides. All strains had the presence of the transposon Tn1546 detected by PCR and were closely related when typed by PFGE. The dissemination of the E. faecalis VanA phenotype among hospitals located in different cities is of great concern because E. faecalis commonly colonizes the gastrointestinal tract of patients and healthy persons for periods varying from weeks to years, which, together with the persistence of vancomycin-resistant Enterococcus in

  16. Structural trends in off stoichiometric chalcopyrite type compound semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Stephan, Christiane

    2011-03-15

    Energy supply is one of the most controversial topics that are currently discussed in our global community. Most of the energy delivered to the customer today has its origin in fossil and nuclear power plants. Indefinable risks and the radioactive waste repository problem of the latter as well as the global scarcity of fossil resources cause the renewable energies to grow more and more important for achieving sustainability. The main renewable energy sources are wind power, hydroelectric power and solar energy. On the photovoltaic (PV) market different materials are competing as part of different kinds of technologies, with the largest contribution still coming from wafer based crystalline silicon solar cells (95 %). Until now thin film solar cells only contribute a small portion to the whole PV market, but large capacities are under construction. Thin film photovoltaic shows a number of advantages in comparison to wafer based crystalline silicon PV. Among these material usage and production cost reduction are two prominent examples. The type of PV materials, which are analyzed in this work, are high potential compounds that are widely used as absorber layer in thin film solar cells. These are compound semiconductors of the type CuB{sup III}C{sup VI}{sub 2} (B{sup III} = In, Ga and C{sup VI} = Se, S). Several years of research have already gone into understanding the efficiency limiting factors for solar cell devices fabricated from this compound. Most of the studies concerning electronic defects are done by spectroscopic methods mostly performed using thin films from different kinds of synthesis, without any real knowledge regarding the structural origin of these defects. This work shows a systematic fundamental structural study of intrinsic point defects that are present within the material at various compositions in CuB{sup III}C{sup VI}{sub 2} compound semiconductors. The study is done on reference powder samples with well determined chemical composition and

  17. Composition of Infinite-Dimensional Linear Dirac-type Structures

    NARCIS (Netherlands)

    Kurula, Mikael; Schaft, Arjan van der; Zwart, Hans

    2006-01-01

    In this paper, we define the Dirac structure and give some fundamental tools for its study. We then proceed by defining composition of "split Dirac structures". In the finite-dimensional case, composition of two Dirac structures always results in a new Dirac structure, but in the Hilbert-space

  18. The Multidimensional Structure of Detonations in Type IA Supernovae

    Science.gov (United States)

    Boisseau, John Richelieu

    1996-01-01

    The thermonuclear explosion of a carbon-oxygen white dwarf that has accreted mass until it approaches the Chandrasekhar limit is widely accepted to be the correct model for Type Ia supernovae (SN Ia). The basic observational characteristics of these models are in general agreement with the observed composition, light curves, and velocities of the ejecta. The mechanism for the explosion, however, is still under debate. Some deflagration models give better agreement with observations, but physical arguments imply that the ignition of a detonation may be unavoidable. Recent numerical models invoking both mechanisms (delayed, or pulsed, detonation models) have yielded promising results. It seems likely that a detonation is at least part of the explosion process for SN Ia. Therefore, understanding detonation propagation in degenerate carbon-oxygen matter is essential. We have constructed a two-dimensional hydrocode with nuclear energy release to study this problem by investigating the multidimensional structure of detonations. Experimental and computational results for detonations in terrestrial fuel-air mixtures show that multidimensional effects are critical to understanding the propagation of real detonations. Multidimensional effects can lead to slower and/or unsteady detonation propagation in simulations of fuel-air mixtures, providing much better agreement with experiments than 1D calculations. We present the first results to show that multidimensional effects are also important for detonations in degenerate carbon -oxygen matter. Perturbations induce transverse waves in the carbon-burning layer, which interact and create pockets of unburned material. This increases the effective size of the induction zone relative to 1D calculations and weakens the detonation. Therefore, the detonation is expected to die at a higher density than predicted by 1D calculations. The presence of these pockets of unburned material also produces a different composition distribution than

  19. Parsing in Dialogue Systems using Typed Feature Structures

    NARCIS (Netherlands)

    op den Akker, Hendrikus J.A.; ter Doest, H.W.L.; Moll, Mark; Nijholt, Antinus

    1995-01-01

    The analysis of natural language in the context of keyboard-driven dialogue systems is the central issue addressed in this paper. A module that corrects typing errors and performs domain-specifc morphological analysis has been developed. A parser for typed unification grammars is designed and

  20. PREDICTING APHASIA TYPE FROM BRAIN DAMAGE MEASURED WITH STRUCTURAL MRI

    OpenAIRE

    Yourganov, Grigori; Smith, Kimberly G.; Fridriksson, Julius; Rorden, Chris

    2015-01-01

    Chronic aphasia is a common consequence of a left-hemisphere stroke. Since the early insights by Broca and Wernicke, studying the relationship between the loci of cortical damage and patterns of language impairment has been one of the concerns of aphasiology. We utilized multivariate classification in a cross-validation framework to predict the type of chronic aphasia from the spatial pattern of brain damage. Our sample consisted of 98 patients with five types of aphasia (Broca’s, Wernicke’s,...

  1. The on axis coupled structure type RF gun

    CERN Document Server

    Oda, F; Nakayama, A; Tanabe, E

    1999-01-01

    The fundamental design of this newly developed RF gun with a thermionic cathode is the pi/2 mode standing wave structure. It has two accelerating cells and a coupling cell located on the beam axis, a so-called on axis coupled structure (OCS). This structure offers a stable operation for high beam current, owing to high group velocity and wide bandwidth. It is important to reduce damage onto the cathode caused by back bombardment, especially for long macropulse operation, such as in an FEL injector. Back bombardment, as well as output beam profile was simulated by using the electromagnetic field analytical codes 'EMSYS'(2D) and 'MAFIA'(3D). The cavity shape was optimized to reduce back bombardment power without sacrificing beam emittance.

  2. On Tanaka's Prolongation Procedure for Filtered Structures of Constant Type

    Directory of Open Access Journals (Sweden)

    Igor Zelenko

    2009-10-01

    Full Text Available We present Tanaka's prolongation procedure for filtered structures on manifolds discovered in [Tanaka N., J. Math. Kyoto. Univ. 10 (1970, 1-82] in a spirit of Singer-Sternberg's description of the prolongation of usual G-structures [Singer I.M., Sternberg S., J. Analyse Math. 15 (1965, 1-114; Sternberg S., Prentice-Hall, Inc., Englewood Cliffs, N.J., 1964]. This approach gives a transparent point of view on the Tanaka constructions avoiding many technicalities of the original Tanaka paper.

  3. Structures of spider toxins: hydroxyindole-3-acetylpolyamines and a new generalized structure of type-E compounds obtained from the venom of the Joro spider, Nephila clavata.

    Science.gov (United States)

    Hisada, M; Fujita, T; Naoki, H; Itagaki, Y; Irie, H; Miyashita, M; Nakajima, T

    1998-08-01

    Facile structure determination of acylpolyamines, glutamatergic nerve blocker obtained from the venom of the Joro spider (Nephila clavata) was carried out with the use of micro-column LC/MS and high energy collision induced dissociation (CID) mass spectrometry. 6-hydroxyindole-3-acetyl was proposed previously as a putative partial structure, for the acyl moiety of hydroxyindole-type polyamines (NPTX-1 to -6). The NMR data obtained for NPTX-6, NPTX-687 and hydroxyindole-3-acetic acid which was released by acid hydrolysis of Nephila clavata crude venom extracts proved that the lipophilic head is the 4-hydroxyindole-3-acetic acid. Various hydroxyindole-3-acetyl polyamines were found in N. Clavata venom and characterized by mass spectrometry. As a result, type-E, a new class of generalized acylpolyamine structure was proposed in addition to the previously reported polyamine backbones type-A to -D.

  4. Investigations on MnSb and related compounds with b8-type structures

    NARCIS (Netherlands)

    Bouwma, Jakob

    1972-01-01

    This thesis describes investigations on phases with hexagonal B8-type structures in the systems Mn-Sb-Sn, Mn-Sb-Te, Mn-Cr-Sb and Mn-V-Sb. In -chapter 1 some general remarks are made on compounds with B8-type structures. The preparation of the samples, and the X-ray crystallographic investigations

  5. Soft phonon mode dynamics in Aurivillius-type structures

    Science.gov (United States)

    Maurya, Deepam; Charkhesht, Ali; Nayak, Sanjeev K.; Sun, Fu-Chang; George, Deepu; Pramanick, Abhijit; Kang, Min-Gyu; Song, Hyun-Cheol; Alexander, Marshall M.; Lou, Djamila; Khodaparast, Giti A.; Alpay, S. P.; Vinh, N. Q.; Priya, Shashank

    2017-10-01

    We report the dynamics of soft phonon modes and their role toward various structural transformations in Aurivillius materials by employing terahertz frequency-domain spectroscopy, atomic pair distribution function analysis, and first-principles calculations. We have chosen B i4T i3O12 as a model system and identified soft phonon modes associated with the paraelectric tetragonal to the ferroelectric monoclinic transition. Three soft phonon modes have been discovered that exhibit a strong temperature dependence. We have determined that the anharmonicity in Bi-O bonds plays a significant role in phonon softening, and that Bi cations play an important role in the emergence of ferroelectricity.

  6. The structural determinants that lead to the formation of particular oligomeric structures in the pancreatic-type ribonuclease family.

    Science.gov (United States)

    Benito, A; Laurents, D V; Ribó, M; Vilanova, M

    2008-08-01

    Pancreatic-type ribonucleases are a family of RNA degrading enzymes that share different degrees of sequence identity but a very similar 3D-structure. The prototype of this family is bovine pancreatic ribonuclease or ribonuclease A. This enzyme has been the object of landmark work on the folding, stability, protein chemistry, catalysis, enzyme-substrate interaction and molecular evolution. In the recent years, the interest in the study of pancreatic-type ribonucleases has increased due to the involvement of some members of this family in special biological functions. In addition, dimeric and also higher oligomeric structures can be attained by the members of this family. The oligomers described structurally to date are mainly formed by 3D-domain swapping, a process which consists of the exchange of identical domains (i.e. identical structural elements, usually the N- and C-termini) between the subunits and is considered to be a mechanism for amyloid-type aggregate formation. This review compares the dimeric and oligomeric structures of different members of the pancreatic-type ribonuclease family which are able to acquire these structures, namely, bovine seminal ribonuclease, ribonuclease A and its human counterpart, human pancreatic ribonuclease. A specific focus is placed on what is known about the structural determinants that lead to the acquisition of a particular oligomeric structure and on the proposed mechanism of 3D-swapping.

  7. Modeling multi-typed structurally viewed chemicals with the UMLS Refined Semantic Network.

    Science.gov (United States)

    Chen, Ling; Morrey, C Paul; Gu, Huanying; Halper, Michael; Perl, Yehoshua

    2009-01-01

    Chemical concepts assigned multiple "Chemical Viewed Structurally" semantic types (STs) in the Unified Medical Language System (UMLS) are subject to ambiguous interpretation. The multiple assignments may denote the fact that a specific represented chemical (combination) is a conjugate, derived via a chemical reaction of chemicals of the different types, or a complex, composed of a mixture of such chemicals. The previously introduced Refined Semantic Network (RSN) is modified to properly model these varied multi-typed chemical combinations. The RSN was previously introduced as an enhanced abstraction of the UMLS's concepts. It features new types, called intersection semantic types (ISTs), each of which explicitly captures a unique combination of ST assignments in one abstract unit. The ambiguous ISTs of different "Chemical Viewed Structurally" ISTs of the RSN are replaced with two varieties of new types, called conjugate types and complex types, which explicitly denote the nature of the chemical interactions. Additional semantic relationships help further refine that new portion of the RSN rooted at the ST "Chemical Viewed Structurally." The number of new conjugate and complex types and the amount of changes to the type assignment of chemical concepts are presented. The modified RSN, consisting of 35 types and featuring 22 new conjugate and complex types, is presented. A total of 800 (about 98%) chemical concepts representing multi-typed chemical combinations from "Chemical Viewed Structurally" STs are uniquely assigned one of the new types. An additional benefit is the identification of a number of illegal ISTs and ST assignment errors, some of which are direct violations of exclusion rules defined by the UMLS Semantic Network. The modified RSN provides an enhanced abstract view of the UMLS's chemical content. Its array of conjugate and complex types provides a more accurate model of the variety of combinations involving chemicals viewed structurally. This

  8. Structural Analysis of Botulinum Neurotoxin Type G Receptor Binding

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, John; Karalewitz, Andrew; Benefield, Desire A.; Mushrush, Darren J.; Pruitt, Rory N.; Spiller, Benjamin W.; Barbieri, Joseph T.; Lacy, D. Borden (Vanderbilt); (MCW)

    2010-10-19

    Botulinum neurotoxin (BoNT) binds peripheral neurons at the neuromuscular junction through a dual-receptor mechanism that includes interactions with ganglioside and protein receptors. The receptor identities vary depending on BoNT serotype (A-G). BoNT/B and BoNT/G bind the luminal domains of synaptotagmin I and II, homologous synaptic vesicle proteins. We observe conditions under which BoNT/B binds both Syt isoforms, but BoNT/G binds only SytI. Both serotypes bind ganglioside G{sub T1b}. The BoNT/G receptor-binding domain crystal structure provides a context for examining these binding interactions and a platform for understanding the physiological relevance of different Syt receptor isoforms in vivo.

  9. Types of Planning Structures of Small Historic Towns of Ukraine

    Directory of Open Access Journals (Sweden)

    Ievgeniia Zapunna

    2015-05-01

    Full Text Available The present article exhibits the results of systematic analysis on structure and planning of fragments of urban environment. The results have been obtained by looking into the prerequisites of formation of urban environment, specifically the impact of the Magdeburg Rights on urban culture. The study covers the small towns in Ukraine, which retained their historical background to a greater extent. 70 towns in Ukraine that had the Magdeburg Law have been analyzed and their historic, architectural and planning capacity investigated. The most valuable urban fragments have been classified in accordance with a number of criteria, such as the form of the plan, planning composition, etc. Based on the conducted analysis the author presents further generalized proposals for comprehensive development of historical and architectural heritage within the socio-cultural and tourism infrastructure of the Ukrainian towns.

  10. UNDERSTANDING THE STRUCTURE OF THE HOT INTERSTELLAR MEDIUM IN NORMAL EARLY-TYPE GALAXIES.

    Science.gov (United States)

    Traynor, Liam; Kim, Dong-Woo; Chandra Galaxy Atlas

    2018-01-01

    The hot interstellar medium (ISM) of early-type galaxies (ETG's) provides crucial insight into the understanding of their formation and evolution. Mechanisms such as type Ia supernovae heating, AGN feedback, deepening potential depth through dark matter assembly and ramp-pressure stripping are known to affect the structure of the ISM. By using temperature maps and radial temperature profiles of the hot ISM from ~70 ETG's with archival Chandra data, it is possible to classify the galaxy's ISM into common structural types. This is extended by using 3D fitting of the radial temperature profile in order to provide models that further constrain the structural types. Five structural types are present, negative (temperature decreases with radii), positive (temperature increases with radii), hybrid-dip (temperature decreases at small radii and increases at large radii), hybrid-bump (inverse of hybrid-dip) and quasi-isothermal (temperature is constant at all radii). This work will be continued by 1) determining which mechanisms are present in which galaxies and 2) analysing the model parameters between galaxies within each structural type to determine whether each type can be described by a single set of model parameters, indicating that the same physical processes are responsible for creating that structural type.

  11. Vertical and Horizontal Vegetation Structure across Natural and Modified Habitat Types at Mount Kilimanjaro.

    Science.gov (United States)

    Rutten, Gemma; Ensslin, Andreas; Hemp, Andreas; Fischer, Markus

    2015-01-01

    In most habitats, vegetation provides the main structure of the environment. This complexity can facilitate biodiversity and ecosystem services. Therefore, measures of vegetation structure can serve as indicators in ecosystem management. However, many structural measures are laborious and require expert knowledge. Here, we used consistent and convenient measures to assess vegetation structure over an exceptionally broad elevation gradient of 866-4550 m above sea level at Mount Kilimanjaro, Tanzania. Additionally, we compared (human)-modified habitats, including maize fields, traditionally managed home gardens, grasslands, commercial coffee farms and logged and burned forests with natural habitats along this elevation gradient. We distinguished vertical and horizontal vegetation structure to account for habitat complexity and heterogeneity. Vertical vegetation structure (assessed as number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) displayed a unimodal elevation pattern, peaking at intermediate elevations in montane forests, whereas horizontal structure (assessed as coefficient of variation of number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) was lowest at intermediate altitudes. Overall, vertical structure was consistently lower in modified than in natural habitat types, whereas horizontal structure was inconsistently different in modified than in natural habitat types, depending on the specific structural measure and habitat type. Our study shows how vertical and horizontal vegetation structure can be assessed efficiently in various habitat types in tropical mountain regions, and we suggest to apply this as a tool for informing future biodiversity and ecosystem service studies.

  12. Types of personality motivation structure of women who are acquiring higher education in psychology

    Directory of Open Access Journals (Sweden)

    TETIANA PARTYKO

    2013-09-01

    Full Text Available The article deals with the results of empirical research on the types of personality motivation structure of women who are acquiring higher education in psychology. Two types have been singled out: expressive and impulsive. The expressive type comprises two components: ideal motivation aimed at life necessities, general activity and social utility, and real motivation aimed at comfort, social status and communication. In the structure of the impulsive type there are three components: real motivation aimed at life necessities, social status, general activity and social utility; real motivation aimed at communication and comfort; creativity motivation aimed at self-development and creative activity. Women belonging to the expressive type of personality motivation structure have more positive self-attitude and a higher level of psychological well-being than women belonging to the impulsive type.

  13. Defect structures in Frank-Kasper type square-triangle tiling of multimodal cage-type mesoporous silicas.

    Science.gov (United States)

    Sakamoto, Yasuhiro

    2017-03-29

    Multimodal cage-type mesoporous silicas (MCMSs) with Frank-Kasper type square-triangle tiling show a unique defect structure, so-called three-fold symmetric hexagons, or shields, which are caused by phason fluctuations in dodecagonal quasicrystals. We observed and characterized three types of configurations inside shields in both quasiperiodic and periodic 32.4.3.4 tiling of MCMSs by transmission electron microscopy (TEM). The high-resolution TEM images of the shields were well explained by polyhedral models, which are the constituents of the Frank-Kasper type tetrahedrally close-packed structures of MCMSs. Shield defects invariably formed because of mismatch in periodic and/or aperiodic square-triangle tiling, and they were also catalyzed by other defects. Multiple shields overlapped with sharing of 30° rhombus units and showed characteristic motifs in the tiling, such as defect-mediated 12-fold wheel and stripe bundle arrangements. Hence, MCMSs with square-triangle tiling would be governed by a random-tiling-like structure stabilized by entropy rather than energy, which results in defect-free tiling.

  14. Photovoltaic properties of ZnO nanorods/p-type Si heterojunction structures

    Directory of Open Access Journals (Sweden)

    Rafal Pietruszka

    2014-02-01

    Full Text Available Selected properties of photovoltaic (PV structures based on n-type zinc oxide nanorods grown by a low temperature hydrothermal method on p-type silicon substrates (100 are investigated. PV structures were covered with thin films of Al doped ZnO grown by atomic layer deposition acting as transparent electrodes. The investigated PV structures differ in terms of the shapes and densities of their nanorods. The best response is observed for the structure containing closely-spaced nanorods, which show light conversion efficiency of 3.6%.

  15. Structural Characterization of Outer Membrane Components of the Type IV Pili System in Pathogenic Neisseria

    NARCIS (Netherlands)

    Jain, Samta; Moscicka, Katarzyna B.; Bos, Martine P.; Pachulec, Emilia; Stuart, Marc C. A.; Keegstra, Wilko; Boekema, Egbert J.; van der Does, Chris; B. Mościcka, K.; Ahmed, Niyaz

    2011-01-01

    Structures of the type IV pili secretin complexes from Neisseria gonorrhoeae and Neisseria meningitidis, embedded in outer membranes were investigated by transmission electron microscopy. Single particle averaging revealed additional domains not observed previously. Secretin complexes of N.

  16. [Antigenic polysaccharides of bacteria: 40. The structures of O-specific polysaccharides from Shigella dysenteriae types 3 and 9 and S. boydii type 4 revised by NMR spectroscopy].

    Science.gov (United States)

    Perepelov, A V; Senchenkova, S N; Shashkov, A S; Lu, B; Feng, L; Vang, L; Knirel', Iu A

    2008-01-01

    The reported structures of O-specific polysaccharides from three standard strains of Shigella bacteria were corrected by modern NMR techniques. The revisions concerned the configuration of the O-glycoside linkage (S. dysenteriae type 3, structure 1), the positions of monosaccharide residue glycosylation and acetylation by pyruvic acid (S. dysenteriae type 9, structure 2), and the attachment position of the side monosaccharide chain (S. boydii type 4, structure 3) [struxture in text].

  17. Structure and Phase Composition of 09G2S Steel Modified by Different Types of Welding

    Science.gov (United States)

    Smirnov, Aleksandr N.; Popova, Natal’ya A.; Nikonenko, Elena L.; Ozhiganov, Evgenii A.; Ababkov, Nikolai V.; Koneva, Nina A.

    2017-10-01

    The paper presents the transmission electron microscopy (TEM) investigations of the structure and phase composition of the type 09G2S weld steel modified by four types of welding, namely: electrode welding and electropercussive welding both with and without the introduction of artificial flaws. Artificial flows are aluminum pieces. TEM investigations are carried out within the heat-affected zone, i.e. between the deposited and base metal, at 0.5 mm distance to the former. Welding electrode of the type E50A is used for welding 09G2S steel specimens. It is shown how the type of welding affects the steel morphology, phase composition, defect structure and its parameters. After each type of welding, the dislocation structure is polarized. This, however, does not cause internal stresses which can destroy the specimen.

  18. Bismuth zinc vanadate, BiZn{sub 2}VO{sub 6}: New crystal structure type and electronic structure

    Energy Technology Data Exchange (ETDEWEB)

    Eliziario Nunes, Sayonara [Department of Chemistry, Durham University, South Road, Durham DH1 3LE (United Kingdom); Department of Materials Engineering, Federal University of São Carlos, 13565-905 São Carlos, SP (Brazil); Wang, Chun-Hai; So, Karwei; Evans, John S.O. [Department of Chemistry, Durham University, South Road, Durham DH1 3LE (United Kingdom); Evans, Ivana Radosavljević, E-mail: ivana.radosavljevic@durham.ac.uk [Department of Chemistry, Durham University, South Road, Durham DH1 3LE (United Kingdom)

    2015-02-15

    We report a combined experimental and computational study of the crystal structure and electronic properties of bismuth zinc vanadate, BiZn{sub 2}VO{sub 6}, known for its visible light photocatalytic activity. The crystal structure has been solved from laboratory powder X-ray diffraction data using the repeated minimisations from random starting values method. BiZn{sub 2}VO{sub 6} adopts a new structure type, based on the following building blocks: corner- and edge-sharing ZnO{sub 4} tetrahedra, ZnO{sub 6} octahedra and VO{sub 4} tetrahedra, and Bi{sub 2}O{sub 12} dimers. It is the only known member of the BiM{sub 2}AO{sub 6} (M=Pb, Ca, Cd, Mn, Zn, Mg, Cu; A=V, P, As) family which does not appear to be structurally closely related to others. The electronic structure of BiZn{sub 2}VO{sub 6}, calculated by DFT methods, shows that it is an indirect gap semiconductor with a calculated band gap of 1.6 eV, which compares favourably to the experimentally measured value of 2.4 eV. - Graphical abstract: The crystal structure of BiZn{sub 2}VO{sub 6}, a new structure type in the BiM{sub 2}AO{sub 6} (M=Mg, Ca, Cd, Cu, Pb, Mn, Zn; A=V, P, As) family. - Highlights: • Structure solution from PXRD data by repeated minimisations from random starting values. • New structure type in the BiM{sub 2}AO{sub 6} (M=Pb, Ca, Cd, Mn, Zn, Mg, Cu; A=V, P, As) family. • Electronic structure calculation.

  19. Ginzburg-Landau-type theory of antiphase boundaries in polytwinned structures

    CERN Document Server

    Vaks, V G

    2001-01-01

    The conventional Landau-Ginzburg theory of interphase boundaries is generalized to the case of not small values of order parameters, with application to polytwinned structures characteristic of cubic-tetragonal-type phase transitions. Explicit expressions for the structure and energy of antiphase boundaries via the functions entering the free energy functional are given. A peculiar dependence of equilibrium orientations of antiphase boundaries on the interaction type is predicted, and it qualitatively agrees with available experimental data

  20. Dung beetle assemblage structure in Tswalu Kalahari Reserve: responses to a mosaic of landscape types, vegetation communities, and dung types.

    Science.gov (United States)

    Davis, Adrian L V; Scholtz, Clarke H; Kryger, Ute; Deschodt, Christian M; Strümpher, Werner P

    2010-06-01

    Tswalu Kalahari Reserve is a private game reserve covering 1,020 km(2) in the Northern Cape, South Africa. It has been created from a number of reclaimed farms and restocked with large indigenous mammals. Two surveys were conducted to inventory the dung beetle fauna (Coleoptera: Scarabaeidae: Scarabaeinae) and determine their spatial patterns and food type associations. The spatial survey used pig dung-baited pitfall traps to examine dung beetle distribution across three main landscape types (plains, dunes, hills) comprising six principal vegetation communities. The food study examined their relative associations with carrion and four different dung types within a single vegetation community. A total of 70 species was recorded. Because the food association study was spatially restricted and conducted under drought conditions, abundance and species richness (47 species) were much lower than in the spatial study (64 species), which was conducted after substantial rainfall. Principal spatial differences in species abundance structure of assemblages were between the sandy southwest plains and dunes; the sandy northern dune fields and plains; and the rocky hills. Forty species analyzed in the food association study showed clear distributional biases to carrion or the dung of elephant (monogastric herbivore), pig (omnivore), cattle and sheep (ruminant herbivores), or pig and cattle. The results (1) show how dung beetle assemblage structure is locally diversified across the heterogeneous landscape of the reserve and (2) indicate how the different dung types dropped by a diverse assemblage of indigenous mammals may variously favor different species of dung beetles.

  1. Experimental and Theoretical Evidences of p-Type Conductivity in Nickel Carbodiimide Nanoparticles with a Delafossite Structure Type.

    Science.gov (United States)

    Jiang, Tengfei; Polteau, Baptiste; Farré, Yoann; Cario, Laurent; Latouche, Camille; Pellegrin, Yann; Boujtita, Mohammed; Odobel, Fabrice; Tessier, Franck; Cheviré, François; Jobic, Stéphane

    2017-07-17

    Nickel carbodiimide (NiCN2) was synthesized using a two-step precipitation-decomposition route leading to a brown powder with gypsum-flower-like morphology and a large specific surface area (75 m2/g). This layered material crystallizes in the 2H structure type of delafossite (space group P63/mmc), which is built upon infinite 2/∞[NiN2] layers connected by linear carbodiimide ([N═C═N]2-) bridges. An X-ray diffraction Rietveld refinement and thermal analyses pointed out some nickel deficiencies in the material, and band structure calculations carried out on the defect compound predicted p-type conductivity in relation to a slight amount of N2-. This p-type conductivity was demonstrated by electrochemical impedance spectroscopy measurements, and a flat band potential of 0.90 V vs SCE at pH 9.4 was measured. This value, which is more positive than those of CuGaO2 and CuCrO2 delafossite oxides and NiO, prompted us to test NiCN2 nanoparticles as a photocathode in p-type dye-sensitized solar cells.

  2. Annular Protofibrils Are a Structurally and Functionally Distinct Type of Amyloid Oligomer*

    OpenAIRE

    Kayed, Rakez; Pensalfini, Anna; Margol, Larry; Sokolov, Yuri; Sarsoza, Floyd; Head, Elizabeth; Hall, James; Glabe, Charles

    2009-01-01

    Amyloid oligomers are believed to play causal roles in several types of amyloid-related neurodegenerative diseases. Several different types of amyloid oligomers have been reported that differ in morphology, size, or toxicity, raising the question of the pathological significance and structural relationships between different amyloid oligomers. Annular protofibrils (APFs) have been described in oligomer preparations of many different amyloidogenic proteins and peptides ...

  3. Dowel-type fastener connections in timber structures subjected to short-term loading

    DEFF Research Database (Denmark)

    Lauritzen Jensen, J.

    Design of dowel-type fastener connections in framed timber structures usually involves a two-step analysis: determination of the distribution of the sectional forces, and design of the eccentrically loaded connections. This report presents an integrated model for design of framed timber structures...

  4. Dance Class Structure Affects Youth Physical Activity and Sedentary Behavior: A Study of Seven Dance Types

    Science.gov (United States)

    Lopez Castillo, Maria A.; Carlson, Jordan A.; Cain, Kelli L.; Bonilla, Edith A.; Chuang, Emmeline; Elder, John P.; Sallis, James F.

    2015-01-01

    Purpose: The study aims were to determine: (a) how class structure varies by dance type, (b) how moderate-to-vigorous physical activity (MVPA) and sedentary behavior vary by dance class segments, and (c) how class structure relates to total MVPA in dance classes. Method: Participants were 291 boys and girls ages 5 to 18 years old enrolled in 58…

  5. Foot Type Biomechanics Part 1: Structure and Function of the Asymptomatic Foot

    Science.gov (United States)

    Hillstrom, Howard J.; Song, Jinsup; Kraszewski, Andrew P.; Hafer, Jocelyn F.; Mootanah, Rajshree; Dufour, Alyssa B.; PT, Betty (Shingpui) Chow; Deland, Jonathan T.

    2012-01-01

    Background Differences in foot structure are thought to be associated with differences in foot function during movement. Many foot pathologies are of a biomechanical nature and often associated with foot type. Fundamental to the understanding of foot pathomechanics is the question: do different foot types have distinctly different structure and function? Aim To determine if objective measures of foot structure and function differ between planus, rectus and cavus foot types in asymptomatic individuals. Methods Sixty-one asymptomatic healthy adults between 18 and 77 years old, that had the same foot type bilaterally (44 planus feet, 54 rectus feet, and 24 cavus feet), were recruited. Structural and functional measurements were taken using custom equipment, an emed-x plantar pressure measuring device, a GaitMatII gait pattern measurement system, and a goniometer. Generalized Estimation Equation modeling was employed to determine if each dependent variable of foot structure and function was significantly different across foot type while accounting for potential dependencies between sides. Post hoc testing was performed to assess pairwise comparisons. Results Several measures of foot structure (malleolar valgus index and arch height index) were significantly different between foot types. Gait pattern parameters were invariant across foot types. Peak pressure, maximum force, pressure-time-integral, force-time-integral and contact area were significantly different in several medial forefoot and arch locations between foot types. Planus feet exhibited significantly different center of pressure excursion indices compared to rectus and cavus feet. Conclusions Planus, rectus and cavus feet exhibited significantly different measures of foot structure and function. PMID:23107625

  6. Structural assessments of plate type support system for APR1400 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Anh Tung; Namgung, Ihn, E-mail: inamgung@kings.ac.kr

    2017-04-01

    Highlights: • This paper investigates plate-type support structure for the reactor vessel of the APR 1400. • The tall column supports of APR1400 reactor challenges in seismic and severe accident events. • A plate-type support of reactor vessel was proposed and evaluated based on ASME code. • The plate-type support was assessed to show its higher rigidity than column-type. - Abstract: This paper investigates an alternative form of support structure for the reactor vessel of the APR 1400. The current reactor vessel adopts a four-column support arrangement locating on the cold legs of the vessel. Although having been successfully designed, the tall column structure challenges in seismic events. In addition, for the mitigation of severe accident consequences, the columns inhibit ex-vessel coolant flow, hence the elimination of the support columns proposes extra safety advantages. A plate-type support was proposed and evaluated for the adequacy of meeting the structural stiffness by Finite Element Analysis (FEA) approach. ASME Boiler and Pressure Vessel Code was used to verify the design. The results, which cover thermal and static structural analysis, show stresses are within allowable limits in accordance with the design code. Even the heat conduction area is increased for the plate-type of support system, the results showed that the thermal stresses are within allowable limits. A comparison of natural frequencies and mode shapes for column support and plate-type support were presented as well which showed higher fundamental frequencies for the plate-type support system resulting in greater rigidity of the support system. From the outcome of this research, the plate-type support is proven to be an alternative to current APR column type support design.

  7. X-ray structure of a soluble Rieske-type ferredoxin from Mus musculus

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Elena J.; Elsen, Nathaniel L.; Seder, Kory D.; McCoy, Jason G.; Fox, Brian G; Phillips, Jr., George N. (UW)

    2009-03-11

    The 2.07 {angstrom} resolution X-ray crystal structure of a soluble Rieske-type ferredoxin from Mus musculus encoded by the gene Mm.266515 is reported. Although they are present as covalent domains in eukaryotic membrane oxidase complexes, soluble Rieske-type ferredoxins have not previously been observed in eukaryotes. The overall structure of the mouse Rieske-type ferredoxin is typical of this class of iron-sulfur proteins and consists of a larger partial {beta}-barrel domain and a smaller domain containing Cys57, His59, Cys80 and His83 that binds the [2Fe-2S] cluster. The S atoms of the cluster are hydrogen-bonded by six backbone amide N atoms in a pattern typical of membrane-bound high-potential eukaryotic respiratory Rieske ferredoxins. However, phylogenetic analysis suggested that the mouse Rieske-type ferredoxin was more closely related to bacterial Rieske-type ferredoxins. Correspondingly, the structure revealed an extended loop most similar to that seen in Rieske-type ferredoxin subunits of bacterial aromatic dioxygenases, including the positioning of an aromatic side chain (Tyr85) between this loop and the [2Fe-2S] cluster. The mouse Rieske-type ferredoxin was shown to be capable of accepting electrons from both eukaryotic and prokaryotic oxidoreductases, although it was unable to serve as an electron donor for a bacterial monooxygenase complex. The human homolog of mouse Rieske-type ferredoxin was also cloned and purified. It behaved identically to mouse Rieske-type ferredoxin in all biochemical characterizations but did not crystallize. Based on its high sequence identity, the structure of the human homolog is likely to be modeled well by the mouse Rieske-type ferredoxin structure.

  8. Dowel-type fastener connections in timber structures subjected to short-term loading

    DEFF Research Database (Denmark)

    Lauritzen Jensen, J.

    Design of dowel-type fastener connections in framed timber structures usually involves a two-step analysis: determination of the distribution of the sectional forces, and design of the eccentrically loaded connections. This report presents an integrated model for design of framed timber structures...... with dowel-type fastener connections. A Finite-Element approach has been adopted. An element has been developed for modelling a plane group of dowel-type fasteners, taking due account of the material and geometric non-linearities, and two different elements have been developed for modelling gap closure...

  9. Type AII lantibiotic bovicin HJ50 with a rare disulfide bond: structure, structure-activity relationships and mode of action.

    Science.gov (United States)

    Zhang, Jie; Feng, Yingang; Teng, Kunling; Lin, Yuheng; Gao, Yong; Wang, Jinfeng; Zhong, Jin

    2014-08-01

    Lantibiotics are ribosomally synthesized antimicrobial peptides containing unusual amino acids. As promising alternatives to conventional antibiotics, they have a high potential for alleviating the problem of emergent antibiotic resistance, with possible applications in many industries that have antibacterial demand. Bovicin HJ50 is a type AII lantibiotic, the largest group of lantibiotics, comprising a linear N-terminal region and a globular C-terminal region. Interestingly, bovicin H50 has a disulfide bond that is rare in this group. Owing to limited information about the spatial structures of type AII lantibiotics, the functional regions of this type and the role of the disulfide bond are still unknown. In the present study, we resolved the solution structure of bovicin HJ50 using NMR spectroscopy. This is the first spatial structure of a type AII lantibiotic. Bovicin HJ50 exhibited high flexibility in aqueous solution, whereas varied rigidities were observed in the different rings with the conserved ring A being the most rigid. The charged residues Lys¹¹, Asp¹² and Lys³⁰, as well as the essential disulfide bond were critical for antimicrobial activity. Importantly, bovicin HJ50 showed not only peptidoglycan precursor lipid II-binding ability, but also pore-forming activity, which is significantly different from other bacteriostatic type AII lantibiotics, suggesting a novel antimicrobial mechanism.

  10. Characterization of fecal vancomycin-resistant enterococci with acquired and intrinsic resistance mechanisms in wild animals, Spain.

    Science.gov (United States)

    Lozano, Carmen; Gonzalez-Barrio, David; Camacho, Maria Cruz; Lima-Barbero, Jose Francisco; de la Puente, Javier; Höfle, Ursula; Torres, Carmen

    2016-11-01

    The objectives were to evaluate the presence of vancomycin-resistant enterococci with acquired (VRE-a) and intrinsic (VRE-i) resistance mechanisms in fecal samples from different wild animals, and analyze their phenotypes and genotypes of antimicrobial resistance. A total of 348 cloacal/rectal samples from red-legged partridges (127), white storks (81), red kites (59), and wild boars (81) (June 2014/February 2015) were inoculated in Slanetz-Bartley agar supplemented with vancomycin (4 μg/mL). We investigated the susceptibility to 12 antimicrobials and the presence of 19 antimicrobial resistance and five virulence genes. In addition, we performed multilocus sequence typing, detection of IS16 and studied Tn1546 structure. One VRE-a isolate was identified in one wild boar. This isolate was identified as Enterococcus faecium, harbored vanA gene included into Tn1546 (truncated with IS1542/IS1216), and belonged to the new ST993. This isolate contained the erm(A), erm(B), tet(M), dfrG, and dfrK genes. Neither element IS16 nor the studied virulence genes were detected. Ninety-six VRE-i isolates were identified (89 Enterococcus gallinarum and seven Enterococcus casseliflavus), with the following prevalence: red kites (71.2 %), white storks (46.9 %), red-legged partridges (7.9 %), and wild boars (4.9 %). Most E. gallinarum isolates showed resistance to tetracycline (66.3 %) and/or erythromycin (46.1 %). High-level resistance to aminoglycosides was present among our VRE-i isolates: kanamycin (22.9 %), streptomycin (11.5 %), and gentamicin (9.4 %). In general, VRE-i isolates of red kites showed higher rates of resistance for non-glycopeptide agents than those of other animal species. The dissemination of acquired resistance mechanisms in natural environments could have implications in the global spread of resistance with public health implications.

  11. Alkaloids from Narcissus poeticus cv. Pink Parasol of various structural types and their biological activity.

    Science.gov (United States)

    Šafratová, Marcela; Hošťálková, Anna; Hulcová, Daniela; Breiterová, Kateřina; Hrabcová, Veronika; Machado, Marta; Fontinha, Diana; Prudêncio, Miguel; Kuneš, Jiří; Chlebek, Jakub; Jun, Daniel; Hrabinová, Martina; Nováková, Lucie; Havelek, Radim; Seifrtová, Martina; Opletal, Lubomír; Cahlíková, Lucie

    2017-12-14

    Fifteen Amaryllidaceae alkaloids (1-15) of various structural types were isolated by standard chromatographic methods from fresh bulbs of Narcissus poeticus cv. Pink Parasol. The chemical structures were elucidated by MS, and 1D and 2D NMR spectroscopic analyses, and by comparison with literature data. Narcipavline (5) and narcikachnine (6) are reported here for the first time. In their structure are combined two basic structural types of Amaryllidaceae alkaloids (galanthamine- and galanthindole-structural types), which represent a new structural type of these compounds. Alkaloids isolated in sufficient amounts were evaluated for their human erythrocytic acetylcholinesterase, and human serum butyrylcholinesterase (HuBuChE) inhibition activity using Ellman's method. Z-Gly-Pro-p-nitroanilide was used as substrate in the prolyl oligopeptidase (POP) assay. Untested alkaloids were also screened for their cytotoxic activity against a small panel of human cancer cells, which spanned cell lines from different tissue types. In parallel, MRC-5 human fibroblasts were employed to determine overall toxicity against noncancerous cells. Some compounds were evaluated for their antiprotozoal activity. The newly isolated alkaloid narcipavline (5) showed interesting HuBuChE inhibition activity (IC50 = 24.4 ± 1.2 µM), and norlycoramine (11) demonstrated promising POP inhibition (IC50 = 0.21 ± 0.01 mM).

  12. Structural and Thermal Safety Analysis Report for the Type B Radioactive Waste Transport Package

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. H.; Seo, K. S.; Lee, J. C.; Bang, K. S

    2007-09-15

    We carried out structural safety evaluation for the type B radioactive waste transport package. Requirements for type B packages according to the related regulations such as IAEA Safety Standard Series No. TS-R-1, Korea Most Act. 2001-23 and US 10 CFR Part 71 were evaluated. General requirements for packages such as those for a lifting attachment, a tie-down attachment and pressure condition were considered. For the type B radioactive waste transport package, the structural, thermal and containment analyses were carried out under the normal transport conditions. Also the safety analysis were conducted under the accidental transport conditions. The 9 m drop test, 1 m puncture test, fire test and water immersion test under the accidental transport conditions were consecutively done. The type B radioactive waste transport packages were maintained the structural and thermal integrities.

  13. Assessing tablet bond types from structural features that affect tablet tensile strength.

    Science.gov (United States)

    Olsson, H; Nyström, C

    2001-02-01

    The aim of this article was to study the possibility of assessing the structural features affecting tablet tensile strength to obtain information on the dominating bond types, i.e. interparticulate attractions, in tablets. The features of the internal tablet structure considered to be important for tablet tensile strength were assessed using a simple tablet model for tablets made from seven materials: potassium chloride, sodium chloride, sodium bicarbonate, lactose, sucrose, microcrystalline cellulose, and ascorbic acid. Tablet porosity and particle size (measured as external specific surface area by permeametry) were the structural features that best correlated with tablet tensile strength. These features were described by a "structural factor," which was combined with tablet tensile strength, as an "interaction factor," to reflect the dominating bond types in tablets. The qualitative results gave dominating bond types in the tablets studied that matched the results of earlier studies, thus supporting the applicability of the method.

  14. [Structures of O-polysaccharides from two Shigella dysenteriae type 8 strains].

    Science.gov (United States)

    Perepelov, A V; Senchenkova, S N; Shashkov, A S; Knirel', Iu A; Lu, B; Feng, L; Wang, L

    2008-01-01

    The structure of the O-polysaccharide (O-antigen) from Shigella dysenteriae type 8 bacteria (strain 599) was corrected using modern NMR techniques (structure 1). The revisions concerned the position of the Glc residue (in the main, but not the side, chain), the site of its substitution, and the configuration of the O-glycoside linkage of the GlcNAc residue. The S. dysenteriae type 8 bacterium (strain G1221), the second investigated representative, was found to produce another structural variant of the O-polysaccharide. It contains GlcNAc instead of the Glc residue in the main chain (structure 2). This data may lead to approval of division of S. dysenteriae type 8 into two subtypes: [Formula: see text].

  15. Subaortic (Type 6 Muscular Band—Innocent Bystander or Pathologic Structure?

    Directory of Open Access Journals (Sweden)

    J Ker

    2010-08-01

    Full Text Available Intraventricular tendons are structures that was identified more than a hundred years ago. It has been suggested that they represent intracavitary radiations of the bundle of His and that they may be an isolated finding or be associated with structural cardiac abnormalities. Loukas et al divided these structures into five categories and recently a sixth type have been added. Various physiological disturbances have been observed due to the sixth type of tendon, such as ST segment elevation and right bundle branch block. It has been noted that this peculiar structure appears too thick to be called a tendon, thus the term band. This retrospective analysis analyzed the incidence of the thick, subaortic (type 6 muscular band in a cardiovascular clinic.

  16. Characterization of blood group ABO(H)-active gangliosides in type AB erythrocytes and structural analysis of type A-active ganglioside variants in type A human erythrocytes.

    Science.gov (United States)

    Kushi, Y; Shimizu, M; Watanabe, K; Kasama, T; Watarai, S; Ariga, T; Handa, S

    2001-02-16

    Several monosialogangliosides containing the type A-active epitope have been detected in type A erythrocytes on immunological analysis with a monoclonal antibody, and three of them were purified by repeated silica bead column chromatography and by scraping from the TLC plate. Two of these A-active gangliosides were characterized by methylation analysis by GC/MS, negative SIMS, MALDI-TOF/MS, proton nuclear magnetic resonance spectroscopy, and immunological assays, and their structures were concluded to be as follows. A-active ganglioside I:A-active ganglioside II:The reactivity of the purified gangliosides to the anti-A monoclonal antibodies (mAbs) exhibited enhancement after removal of the sialic acid. Therefore, the sialic residue has been shown to inhibit the binding to the terminal A-active epitope through the formation of an immune complex. To confirm the presence of A- (including S-A-I, -II and -III) and B-active gangliosides, the reactivity of anti-A and -B mAbs were investigated using total gangliosides from type A, -B and -AB erythrocytes on TLC plate. The results were that the gangliosides from types A and AB showed positive reaction to anti-A mAbs, whereas in the anti-B mAbs binding the gangliosides from types B and AB were positive. Thus, it revealed that A-active gangliosides were present in type A and -AB, and B-active gangliosides in types B and AB. As there was no difference in respective gangliosides on type AB erythrocytes of 22 individuals, both A- and B-active gangliosides are equally present in type AB erythrocytes. The biological significance of these A- and B-active ganglioside variants remains vague at present. As these molecules exhibit different reactivities to the anti-A mAbs, it is very likely that they can regulate the antigenicity of the A-epitope on the cell surface.

  17. Development, characteristics and comparative structural analysis of tensegrity type cable domes

    Directory of Open Access Journals (Sweden)

    Nenadović Aleksandra

    2010-01-01

    Full Text Available Tensegrity type cable domes are three-dimensional structural configurations, prestressed inside the perimeter compression ring, in which the continuous tension throughout the roof structure is made by continuous tension cables and discontinuous compression struts. These kinds of structures can be formed like spatially triangulated networks or like networks nontriangulated in space. This paper examines some effects of network geometry on the behaviour and structural efficiency of tensegrity type cable domes. In this paper the roof cover is considered non-interactive with the supporting structure, unlike rigidly clad tensegrity type cable domes. Since the main bearing elements of tensegrity type cable domes are prestressed cables, they show non-linear load deformation and rely upon geometric stiffness. A geometrically non-linear analysis of non-triangulated and triangulated structures for different load conditions was conducted employing a computer program based on the perturbation theory. The incrementally-iterative procedure, with an approximation of the stiffness matrix by combining the elastic and geometric stiffness matrix, allows detection of structural instabilities.

  18. The structural, magnetic and electronic properties of p-type and n-type doped monolayer WS2 systems

    Science.gov (United States)

    Zhu, Yuan-Yan; Zhang, Jian-Min

    2017-12-01

    The structural, magnetic and electronic properties of the p-type (group VA elements N, P, As or Sb) and n-type (group VIIA elements Cl, Br, I or At) doped monolayer WS2 systems have been systematically investigated using the spin-polarized first-principle calculations. The results show that whether p-type or n-type doped monolayer WS2 systems, the greater the atomic radius of the dopant X, the greater the bond length dX-W and height difference hS, but the smaller the bond angle θW-X-W . All doped systems are easier to form and more stable under W-rich condition than S-rich condition. Specially, the N- and Cl-doped cases are the most stable in p-type and n-type doped monolayer WS2 systems, respectively. The total magnetic moment Mtot of the N-doped system is 0.773μB contributed mainly by N-p orbitals, the total magnetic moments Mtot of the P-, As- and Sb-doped systems are all approximately zero, and the total magnetic moments Mtot of the Cl-, Br-, I- and At-doped systems are 0.543, 0.810, 0.989 and 0.999μB , respectively, contributed mainly by the first nearest-neighbor atom W-d orbitals. Although the pristine monolayer WS2 system is a nonmagnetic semiconductor, the doped system changes to magnetic semiconductor for N-doped system, nonmagnetic metal for P-, As- and Sb-doped systems, magnetic metal for Cl- and Br-doped systems and magnetic half-metal for I- and At-doped systems.

  19. Life Comparative Analysis of Energy Consumption and CO2 Emissions of Different Building Structural Frame Types

    Directory of Open Access Journals (Sweden)

    Sangyong Kim

    2013-01-01

    Full Text Available The objective of this research is to quantitatively measure and compare the environmental load and construction cost of different structural frame types. Construction cost also accounts for the costs of CO2 emissions of input materials. The choice of structural frame type is a major consideration in construction, as this element represents about 33% of total building construction costs. In this research, four constructed buildings were analyzed, with these having either reinforced concrete (RC or steel (S structures. An input-output framework analysis was used to measure energy consumption and CO2 emissions of input materials for each structural frame type. In addition, the CO2 emissions cost was measured using the trading price of CO2 emissions on the International Commodity Exchange. This research revealed that both energy consumption and CO2 emissions were, on average, 26% lower with the RC structure than with the S structure, and the construction costs (including the CO2 emissions cost of the RC structure were about 9.8% lower, compared to the S structure. This research provides insights through which the construction industry will be able to respond to the carbon market, which is expected to continue to grow in the future.

  20. The Types of Argument Structure Used by Hillary Clinton in the CNN Democratic Presidential Debate

    Directory of Open Access Journals (Sweden)

    Anggie Angeline

    2009-01-01

    Full Text Available This qualitative research was conducted to examine the types of argument structure by Hillary Clinton in part one of the CNN Democratic Presidential Debate since Hillary, who had a great deal of experiences in political parties, was supposed to be able to construct convincing arguments that had good argument structures. The theories used to analyze were Bierman and Assali’s (1996, King’s (n.d. and Stanlick’s (2003. The findings showed that there were five types of argument structure used: serial, linked, convergent, divergent, and hybrid argument structures. The linked argument structure was the argument structure used the most frequently in Hillary’s utterances in the debate, while the divergent was the least one. Thus, it could be concluded that Hillary’s speech in the Presidential Debate was quite interesting since she could combine all the five types of argument structure, though the frequency of using them was not the same and it seems that linked argument structure was the most effective strategy for her in arguing about the politic, economy, and social issues.

  1. Optimum Design for Slot-type of Stator Based on PM Motor with Halbach Structure

    Directory of Open Access Journals (Sweden)

    Zhu Yongxin

    2015-01-01

    Full Text Available The performance of permanent magnet motor is directly influenced by the PM structure of rotor and the slot type of stator. An emerging rotor magnetization type of PM motor is Halbach structure, which has obvious advantages in comparison to ordinary permanent structures and in application, especially in the design of propeller integration system. Commonly, Halbach array is used in discrete permanent magnet structure on the rotor of machine. On the stator, air gap flux density varies as the slot type changes, and complex slot types will bring about complex air gap equivalent process of the motor, which will influence the procedures of simulation calculation and experiments. According to the characteristics of Halbach array, the intensifying effect of the Halbach array on magnetic flux density of air gap is analyzed in this paper, and the electromagnetic field of PM motor is calculated. By using FEM method, the magnetic flux density of air gap, back phase electromotive force and electromagnetic torque are compared under different slot types. Simulation result shows the peer slot is best. Experiments on a 60kW PM Motor with Halbach Structure and peer slot is in good agreement with simulation.

  2. In Situ D-periodic Molecular Structure of Type II Collagen

    Energy Technology Data Exchange (ETDEWEB)

    Antipova, Olga; Orgel, Joseph P.R.O. (IIT)

    2010-05-06

    Collagens are essential components of extracellular matrices in multicellular animals. Fibrillar type II collagen is the most prominent component of articular cartilage and other cartilage-like tissues such as notochord. Its in situ macromolecular and packing structures have not been fully characterized, but an understanding of these attributes may help reveal mechanisms of tissue assembly and degradation (as in osteo- and rheumatoid arthritis). In some tissues such as lamprey notochord, the collagen fibrillar organization is naturally crystalline and may be studied by x-ray diffraction. We used diffraction data from native and derivative notochord tissue samples to solve the axial, D-periodic structure of type II collagen via multiple isomorphous replacement. The electron density maps and heavy atom data revealed the conformation of the nonhelical telopeptides and the overall D-periodic structure of collagen type II in native tissues, data that were further supported by structure prediction and transmission electron microscopy. These results help to explain the observed differences in collagen type I and type II fibrillar architecture and indicate the collagen type II cross-link organization, which is crucial for fibrillogenesis. Transmission electron microscopy data show the close relationship between lamprey and mammalian collagen fibrils, even though the respective larger scale tissue architecture differs.

  3. Crystal Structure of the Receptor-Binding Domain of Botulinum Neurotoxin Type HA, Also Known as Type FA or H

    Directory of Open Access Journals (Sweden)

    Guorui Yao

    2017-03-01

    Full Text Available Botulinum neurotoxins (BoNTs, which have been exploited as cosmetics and muscle-disorder treatment medicines for decades, are well known for their extreme neurotoxicity to humans. They pose a potential bioterrorism threat because they cause botulism, a flaccid muscular paralysis-associated disease that requires immediate antitoxin treatment and intensive care over a long period of time. In addition to the existing seven established BoNT serotypes (BoNT/A–G, a new mosaic toxin type termed BoNT/HA (aka type FA or H was reported recently. Sequence analyses indicate that the receptor-binding domain (HC of BoNT/HA is ~84% identical to that of BoNT/A1. However, BoNT/HA responds differently to some potent BoNT/A-neutralizing antibodies (e.g., CR2 that target the HC. Therefore, it raises a serious concern as to whether BoNT/HA poses a new threat to our biosecurity. In this study, we report the first high-resolution crystal structure of BoNT/HA-HC at 1.8 Å. Sequence and structure analyses reveal that BoNT/HA and BoNT/A1 are different regarding their binding to cell-surface receptors including both polysialoganglioside (PSG and synaptic vesicle glycoprotein 2 (SV2. Furthermore, the new structure also provides explanations for the ~540-fold decreased affinity of antibody CR2 towards BoNT/HA compared to BoNT/A1. Taken together, these new findings advance our understanding of the structure and function of this newly identified toxin at the molecular level, and pave the way for the future development of more effective countermeasures.

  4. Crystal Structure of the Receptor-Binding Domain of Botulinum Neurotoxin Type HA, Also Known as Type FA or H

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Guorui; Lam, Kwok-ho; Perry, Kay; Weisemann, Jasmin; Rummel, Andreas; Jin, Rongsheng (Cornell); (Dusseldorf); (UCI)

    2017-03-01

    Botulinum neurotoxins (BoNTs), which have been exploited as cosmetics and muscle-disorder treatment medicines for decades, are well known for their extreme neurotoxicity to humans. They pose a potential bioterrorism threat because they cause botulism, a flaccid muscular paralysis-associated disease that requires immediate antitoxin treatment and intensive care over a long period of time. In addition to the existing seven established BoNT serotypes (BoNT/A–G), a new mosaic toxin type termed BoNT/HA (aka type FA or H) was reported recently. Sequence analyses indicate that the receptor-binding domain (HC) of BoNT/HA is ~84% identical to that of BoNT/A1. However, BoNT/HA responds differently to some potent BoNT/A-neutralizing antibodies (e.g., CR2) that target the HC. Therefore, it raises a serious concern as to whether BoNT/HA poses a new threat to our biosecurity. In this study, we report the first high-resolution crystal structure of BoNT/HA-HC at 1.8 Å. Sequence and structure analyses reveal that BoNT/HA and BoNT/A1 are different regarding their binding to cell-surface receptors including both polysialoganglioside (PSG) and synaptic vesicle glycoprotein 2 (SV2). Furthermore, the new structure also provides explanations for the ~540-fold decreased affinity of antibody CR2 towards BoNT/HA compared to BoNT/A1. Taken together, these new findings advance our understanding of the structure and function of this newly identified toxin at the molecular level, and pave the way for the future development of more effective countermeasures

  5. Structural insights into DNA sequence recognition by Type ISP restriction-modification enzymes.

    Science.gov (United States)

    Kulkarni, Manasi; Nirwan, Neha; van Aelst, Kara; Szczelkun, Mark D; Saikrishnan, Kayarat

    2016-05-19

    Engineering restriction enzymes with new sequence specificity has been an unaccomplished challenge, presumably because of the complexity of target recognition. Here we report detailed analyses of target recognition by Type ISP restriction-modification enzymes. We determined the structure of the Type ISP enzyme LlaGI bound to its target and compared it with the previously reported structure of a close homologue that binds to a distinct target, LlaBIII. The comparison revealed that, although the two enzymes use almost a similar set of structural elements for target recognition, the residues that read the bases vary. Change in specificity resulted not only from appropriate substitution of amino acids that contacted the bases but also from new contacts made by positionally distinct residues directly or through a water bridge. Sequence analyses of 552 Type ISP enzymes showed that the structural elements involved in target recognition of LlaGI and LlaBIII were structurally well-conserved but sequentially less-conserved. In addition, the residue positions within these structural elements were under strong evolutionary constraint, highlighting the functional importance of these regions. The comparative study helped decipher a partial consensus code for target recognition by Type ISP enzymes. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  6. Nonlinear dynamic systems identification using recurrent interval type-2 TSK fuzzy neural network - A novel structure.

    Science.gov (United States)

    El-Nagar, Ahmad M

    2017-10-31

    In this study, a novel structure of a recurrent interval type-2 Takagi-Sugeno-Kang (TSK) fuzzy neural network (FNN) is introduced for nonlinear dynamic and time-varying systems identification. It combines the type-2 fuzzy sets (T2FSs) and a recurrent FNN to avoid the data uncertainties. The fuzzy firing strengths in the proposed structure are returned to the network input as internal variables. The interval type-2 fuzzy sets (IT2FSs) is used to describe the antecedent part for each rule while the consequent part is a TSK-type, which is a linear function of the internal variables and the external inputs with interval weights. All the type-2 fuzzy rules for the proposed RIT2TSKFNN are learned on-line based on structure and parameter learning, which are performed using the type-2 fuzzy clustering. The antecedent and consequent parameters of the proposed RIT2TSKFNN are updated based on the Lyapunov function to achieve network stability. The obtained results indicate that our proposed network has a small root mean square error (RMSE) and a small integral of square error (ISE) with a small number of rules and a small computation time compared with other type-2 FNNs. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  7. 1H and 15N NMR resonance assignments and secondary structure of titin type I domains

    Energy Technology Data Exchange (ETDEWEB)

    Muhle-Goll, Claudia; Nilges, Michael; Pastore, Annalisa [European Molecular Biology Laboratory (Germany)

    1997-01-15

    Titin/connect in is a giant muscle protein with a highly modular architecture consisting of multiple repeats of two sequence motifs, named type I and type II. Type I modules have been suggested to be intracellular members of the fibronectin type III (Fn3) domain family. Along the titin sequence they are exclusively present in the region of the molecule located in the sarcomere A-band. This region has been shown to interact with myosin and C-protein. One of the most noticeable features of type I modules is that they are particularly rich in semiconserved prolines, since these residues account for about 8% of their sequence. We have determined the secondary structure of a representative type I domain (A71) by 15N and 1HNMR. We show that the type I domains of titin have the Fn3 fold as proposed, consisting of a three- and a four-stranded {beta}-sheet. When the two sheets are placed on top of each other to form the {beta}-sandwich characteristic of the Fn3 fold, 8 out of 10 prolines are found on the same side of the molecule and form an exposed hydrophobic patch. This suggests that the semiconserved prolines might be relevant for the function of type I modules, providing a surface for binding to other A-band proteins. The secondary structure of A71 was structurally aligned to other extracellular Fn3 modules of known 3D structure. The alignment shows that titin type I modules have closest similarity to the first Fn3 domain of Drosophila neuroglian.

  8. Foot Type Biomechanics Part 2: Are structure and anthropometrics related to function?

    Science.gov (United States)

    Mootanah, Rajshree; Song, Jinsup; Lenhoff, Mark W.; Hafer, Jocelyn F.; Backus, Sherry I.; Gagnon, David; Deland, Jonathan T.; Hillstrom, Howard J.

    2013-01-01

    Background Many foot pathologies are associated with specific foot types. If foot structure and function are related, measurement of either could assist with differential diagnosis of pedal pathologies. Hypothesis Biomechanical measures of foot structure and function are related in asymptomatic healthy individuals. Methods Sixty-one healthy subjects' left feet were stratified into cavus (n = 12), rectus (n = 27) and planus (n = 22) foot types. Foot structure was assessed by malleolar valgus index, arch height index, and arch height flexibility. Anthropometrics (height and weight), age, and walking speed were measured. Foot function was assessed by center of pressure excursion index, peak plantar pressure, maximum force, and gait pattern parameters. Foot structure and anthropometric variables were entered into stepwise linear regression models to identify predictors of function. Results Measures of foot structure and anthropometrics explained 10–37% of the model variance (adjusted R2) for gait pattern parameters. When walking speed was included, the adjusted R2 increased to 45–77% but foot structure was no longer a factor. Foot structure and anthropometrics predicted 7–47% of the model variance for plantar pressure and 16–64% for maximum force parameters. All multivariate models were significant (p Foot structure and function are related in asymptomatic healthy individuals. The structural parameters employed are basic measurements that do not require ionizing radiation and could be used in a clinical setting. Further research is needed to identify additional predictive parameters (plantar soft tissue characteristics, skeletal alignment, and neuromuscular control) and to include individuals with pathology. PMID:23107624

  9. X-ray structure of a soluble Rieske-type ferredoxin from Mus musculus

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Elena J.; Elsen, Nathaniel L. [Department of Biochemistry, University of Wisconsin, Madison (United States); Seder, Kory D. [Center for Eukaryotic Structural Genomics, University of Wisconsin, Madison (United States); McCoy, Jason G. [Department of Biochemistry, University of Wisconsin, Madison (United States); Fox, Brian G.; Phillips Jr, George N., E-mail: phillips@biochem.wisc.edu [Department of Biochemistry, University of Wisconsin, Madison (United States); Center for Eukaryotic Structural Genomics, University of Wisconsin, Madison (United States)

    2008-09-01

    The X-ray crystal structure of a soluble Rieske ferredoxin from M. musculus was solved at 2.07 Å resolution, revealing an iron–sulfur cluster-binding domain with similar architecture to the Rieske-type domains of bacterial aromatic dioxygenases. The ferredoxin was also shown to be capable of accepting electrons from both eukaryotic and prokaryotic oxidoreductases. The 2.07 Å resolution X-ray crystal structure of a soluble Rieske-type ferredoxin from Mus musculus encoded by the gene Mm.266515 is reported. Although they are present as covalent domains in eukaryotic membrane oxidase complexes, soluble Rieske-type ferredoxins have not previously been observed in eukaryotes. The overall structure of the mouse Rieske-type ferredoxin is typical of this class of iron–sulfur proteins and consists of a larger partial β-barrel domain and a smaller domain containing Cys57, His59, Cys80 and His83 that binds the [2Fe–2S] cluster. The S atoms of the cluster are hydrogen-bonded by six backbone amide N atoms in a pattern typical of membrane-bound high-potential eukaryotic respiratory Rieske ferredoxins. However, phylogenetic analysis suggested that the mouse Rieske-type ferredoxin was more closely related to bacterial Rieske-type ferredoxins. Correspondingly, the structure revealed an extended loop most similar to that seen in Rieske-type ferredoxin subunits of bacterial aromatic dioxygenases, including the positioning of an aromatic side chain (Tyr85) between this loop and the [2Fe–2S] cluster. The mouse Rieske-type ferredoxin was shown to be capable of accepting electrons from both eukaryotic and prokaryotic oxidoreductases, although it was unable to serve as an electron donor for a bacterial monooxygenase complex. The human homolog of mouse Rieske-type ferredoxin was also cloned and purified. It behaved identically to mouse Rieske-type ferredoxin in all biochemical characterizations but did not crystallize. Based on its high sequence identity, the structure of the

  10. Two-stage multishape segmentation of brain structures using image intensity, tissue type, and location information.

    Science.gov (United States)

    Akhondi-Asl, Alireza; Soltanian-Zadeh, Hamid

    2010-08-01

    The authors propose a fast, robust, nonparametric, entropy-based, coupled, multishape approach to segment subcortical brain structures from magnetic resonance images (MRIs). The proposed method uses three types of information: Image intensity, tissue types, and locations of structures. The image intensity information is captured by estimating the probability density function (pdf) of the image intensities in each structure. The tissue type information is captured by applying an unsupervised tissue segmentation method to the image and estimating a probability mass function (pmf) for the tissue type of each structure. The location information is captured by estimating pdf of the location of each structure from the training datasets. The resulting pmf's and pdf's are used to define an entropy function whose minimum corresponds to a desirable segmentation of the structures. The authors propose a three-step optimization strategy for the segmentation method. In the first step, a powerful automatic initialization method is developed based on tissue type and location information of the structures. In the second step, a quasi-Newton method is used to optimize the parameters of the energy function. To speed up the iterations, derivatives of the energy function with respect to its parameters are analytically derived and used in the optimization process. In the last step, the limitations related to the prior shape model are removed and a level-set method is applied for the fine tuning of the segmentation results. The proposed method is applied to two different datasets and the results are compared to those of previous methods in literature. Experimental results are presented for lateral ventricles, caudate, thalamus, putamen, pallidum, hippocampus, and amygdala. The results illustrate superior performance of the proposed segmentation method compared to other methods in literature. The execution time of the algorithm is a few minutes, suitable for a variety of applications.

  11. Optical identification of quantum dot types in CdSe/ZnSe structures

    Science.gov (United States)

    Straßburg, M.; Deniozou, Th; Hoffmann, A.; Rodt, S.; Türck, V.; Heitz, R.; Pohl, U. W.; Bimberg, D.; Litvinov, D.; Rosenauer, A.; Gerthsen, D.; Schwedhelm, S.; Kudryashov, I.; Lischka, K.; Schikora, D.

    2000-06-01

    Two different types of quantum islands, formed either by strain-modified island growth or in the Stranski-Krastanow (SK) mode, were identified by optical and structural investigations. Pronounced differences in the size, shape and Cd content of these islands lead to different localisation energies of three-dimensionally confined excitons allowing a clear distinction of both island types. The classification was confirmed by plan-view and cross-sectional transmission electron microscopy.

  12. Type-II Quantum Dot Nanowire Structures with Large Oscillator Strengths for Optical Quantum Gating Applications

    DEFF Research Database (Denmark)

    Taherkhani, Masoomeh; Gregersen, Niels; Willatzen, Morten

    2017-01-01

    The exciton oscillator strength (OS) in type-II quantum dot (QD) nanowires is calculated by using a fast and efficient method. We propose a new structure in Double-Well QD (DWQD) nanowire that considerably increases OS of type-II QDs which is a key parameter in optical quantum gating in the stimu...... in the stimulated Raman adiabatic passage (STIRAP) process [1] for implementing quantum gates....

  13. Allelic diversity and population structure of Bacillus sphaericus as revealed by multilocus sequence typing.

    Science.gov (United States)

    Ge, Yong; Hu, Xiaomin; Zheng, Dasheng; Wu, Yiming; Yuan, Zhiming

    2011-08-01

    The genetic diversity of 35 Bacillus sphaericus strains was analyzed by a newly developed multilocus sequence typing (MLST) scheme, toxin gene pool survey, and mosquito bioassay. The results demonstrated that strains assigned to the same sequence type (ST) had the same occurrence of toxin genes. Further sequence analysis revealed that toxic strains presented a nearly clonal population structure, whereas nontoxic strains had a high level of heterogeneity and were significantly distinct from toxic strains.

  14. Allelic Diversity and Population Structure of Bacillus sphaericus as Revealed by Multilocus Sequence Typing ▿ †

    Science.gov (United States)

    Ge, Yong; Hu, Xiaomin; Zheng, Dasheng; Wu, Yiming; Yuan, Zhiming

    2011-01-01

    The genetic diversity of 35 Bacillus sphaericus strains was analyzed by a newly developed multilocus sequence typing (MLST) scheme, toxin gene pool survey, and mosquito bioassay. The results demonstrated that strains assigned to the same sequence type (ST) had the same occurrence of toxin genes. Further sequence analysis revealed that toxic strains presented a nearly clonal population structure, whereas nontoxic strains had a high level of heterogeneity and were significantly distinct from toxic strains. PMID:21685170

  15. A Study of the Types of Organizational Structure in Venezuelan University Institutes

    Directory of Open Access Journals (Sweden)

    Rafael Antonio Pertuz Belloso

    2013-12-01

    Full Text Available This study aimed at identifying the type of organizational structure of Venezuelan university institutes. It is a field investigation of a descriptive nature with a non-experimental transactional field design. We worked with a population sample consisting of a director, assistant directors, academic assistant directors and eighty-eight teachers from technological institutes in Cabimas and Maracaibo in Venezuela. A survey, in the form of a questionnaire, was used as the data collection technique, which included 24 items, validated by 5 experts, with Cronbach Alpha reliability of 0.93. The data analysis technique utilized was the percentage frequency distribution. The results indicated the coexistence of bureaucratic structural typologies; departmental and simple. An implementation of a structural migration strategy to the implementation of a matrix-type structure is recommended.

  16. Analysis of shell-type structures subjected to time-dependent mechanical and thermal loading

    Science.gov (United States)

    Simitses, G. J.

    1989-01-01

    The objective is to develop a general mathematical model and solution methodologies for analyzing structural response of thin, metallic shell-type structures under large transient, cyclic, or static thermomechanical loads. Among the system responses, which are associated with these load conditions, are thermal buckling, creep buckling, and racheting. Thus, geometric as well as material-type nonlinearities (of high order) can be anticipated and must be considered in the development of the mathematical model. Furthermore, this must also be accommodated in the solution procedures.

  17. Properties of the complex type II burst with rich herringbone structure within 3-33 MHz

    Science.gov (United States)

    Dorovskyy, V. V.; Melnik, V. M.; Konovalenko, O. O.; Brazhenko, A. I.; Panchenko, M.; Rucker, H. O.; Poedts, S.; Stanislavsky, A. A.; Mykhaylov, V. A.

    2013-06-01

    Characteristics of the type II burst with "herringbone" structure observed on 7 June 2011 within 3-33 MHz are considered. The burst was recorded both by the two ground-based radiotelescopes (UTR-2, URAN-2) and the spaceborne STEREO radio receivers. For the first time, a detailed statistical analysis of main parameters of the herringbone sub- bursts of type II (duration and frequency drift rate) was performed at decameter wavelengths separately for those positively and negatively drifting ones. Another new result within these frequencies is the measured degree of circular polarization of fine structure type II bursts. A fine frequency, structure of the sub-bursts herringbone was found to be, similar to the so-called "fringes" in the solar S-bursts. From the characteristic wave-like oscillations of the type II back-bone the parameters of coronal streamers intersected by the shock wave were derived. Using the observational data from the STEREO and SOHO spacecraft, the speed and direction of the associated CME propagation were detected. From the ground-based radio observations the radial speed of type II burst source was found. As a result, possible location of the type II burst source was determined. In addition, the geoeffectiveness of the discussed solar event was estimated.

  18. Optimal Multi-Type Sensor Placement for Structural Identification by Static-Load Testing

    Science.gov (United States)

    Papadopoulou, Maria; Vernay, Didier; Smith, Ian F. C.

    2017-01-01

    Assessing ageing infrastructure is a critical challenge for civil engineers due to the difficulty in the estimation and integration of uncertainties in structural models. Field measurements are increasingly used to improve knowledge of the real behavior of a structure; this activity is called structural identification. Error-domain model falsification (EDMF) is an easy-to-use model-based structural-identification methodology which robustly accommodates systematic uncertainties originating from sources such as boundary conditions, numerical modelling and model fidelity, as well as aleatory uncertainties from sources such as measurement error and material parameter-value estimations. In most practical applications of structural identification, sensors are placed using engineering judgment and experience. However, since sensor placement is fundamental to the success of structural identification, a more rational and systematic method is justified. This study presents a measurement system design methodology to identify the best sensor locations and sensor types using information from static-load tests. More specifically, three static-load tests were studied for the sensor system design using three types of sensors for a performance evaluation of a full-scale bridge in Singapore. Several sensor placement strategies are compared using joint entropy as an information-gain metric. A modified version of the hierarchical algorithm for sensor placement is proposed to take into account mutual information between load tests. It is shown that a carefully-configured measurement strategy that includes multiple sensor types and several load tests maximizes information gain. PMID:29240684

  19. Crystal Structure of Wild-Type Centrin 1 from Mus musculus Occupied by Ca2.

    Science.gov (United States)

    Kim, So Young; Kim, Da Som; Hong, Joo Eun; Park, Jung Hee

    2017-10-01

    Mus musculus centrin 1 (MmCen1) is located at the cilium of photoreceptor cells connecting the outer segment through signal transduction components to the metabolically active inner segment. In the cilium, MmCen1 is involved in the translocation of transducin between compartments as a result of photoreceptor activation. In this study, we report the crystal structure of wild-type MmCen1 and its Ca2+-binding properties using structure-based mutagenesis. The crystal structure exhibits three structural features, i.e. four Ca2+ equally occupied at each EF-hand motif, structural changes accompanying helix motion at the N- and C-lobes, and adoption of N-C type dimerization when Ca2+ binds to EF-hand I and II in the N-lobe. The presence of MmCen1 dimers was confirmed in solution by native PAGE. Isothermal titration calorimetry data showed sequential binding of Ca2+ at four independent sites. Mutations S45A and D49A in EF-hand I alone disrupted the Ca2+-binding property of the wild-type protein. Based on the crystal structure of MmCen1, we suggest that a dimerization mode between the N- and C-lobes may be required by Ca2+ binding at the N-lobe.

  20. The Cryoelectron Microscopy Structure of the Type 1 Chaperone-Usher Pilus Rod.

    Science.gov (United States)

    Hospenthal, Manuela K; Zyla, Dawid; Costa, Tiago R D; Redzej, Adam; Giese, Christoph; Lillington, James; Glockshuber, Rudi; Waksman, Gabriel

    2017-12-05

    Adhesive chaperone-usher pili are long, supramolecular protein fibers displayed on the surface of many bacterial pathogens. The type 1 and P pili of uropathogenic Escherichia coli (UPEC) play important roles during urinary tract colonization, mediating attachment to the bladder and kidney, respectively. The biomechanical properties of the helical pilus rods allow them to reversibly uncoil in response to flow-induced forces, allowing UPEC to retain a foothold in the unique and hostile environment of the urinary tract. Here we provide the 4.2-Å resolution cryo-EM structure of the type 1 pilus rod, which together with the previous P pilus rod structure rationalizes the remarkable "spring-like" properties of chaperone-usher pili. The cryo-EM structure of the type 1 pilus rod differs in its helical parameters from the structure determined previously by a hybrid approach. We provide evidence that these structural differences originate from different quaternary structures of pili assembled in vivo and in vitro. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Distributions of amino acids suggest that certain residue types more effectively determine protein secondary structure.

    Science.gov (United States)

    Saraswathi, S; Fernández-Martínez, J L; Koliński, A; Jernigan, R L; Kloczkowski, A

    2013-10-01

    Exponential growth in the number of available protein sequences is unmatched by the slower growth in the number of structures. As a result, the development of efficient and fast protein secondary structure prediction methods is essential for the broad comprehension of protein structures. Computational methods that can efficiently determine secondary structure can in turn facilitate protein tertiary structure prediction, since most methods rely initially on secondary structure predictions. Recently, we have developed a fast learning optimized prediction methodology (FLOPRED) for predicting protein secondary structure (Saraswathi et al. in JMM 18:4275, 2012). Data are generated by using knowledge-based potentials combined with structure information from the CATH database. A neural network-based extreme learning machine (ELM) and advanced particle swarm optimization (PSO) are used with this data to obtain better and faster convergence to more accurate secondary structure predicted results. A five-fold cross-validated testing accuracy of 83.8 % and a segment overlap (SOV) score of 78.3 % are obtained in this study. Secondary structure predictions and their accuracy are usually presented for three secondary structure elements: α-helix, β-strand and coil but rarely have the results been analyzed with respect to their constituent amino acids. In this paper, we use the results obtained with FLOPRED to provide detailed behaviors for different amino acid types in the secondary structure prediction. We investigate the influence of the composition, physico-chemical properties and position specific occurrence preferences of amino acids within secondary structure elements. In addition, we identify the correlation between these properties and prediction accuracy. The present detailed results suggest several important ways that secondary structure predictions can be improved in the future that might lead to improved protein design and engineering.

  2. Surface-dependent conductivity, transition type, and energy band structure in amorphous indium tin oxide films

    Science.gov (United States)

    Wang, Yaqin; Tang, Wu

    2017-12-01

    Amorphous indium tin oxide (ITO) thin films were deposited on polymethylmethacrylate and polyethyleneterephthalate substrates by radio frequency magnetron sputtering at room temperature. An interesting substrate morphology effect of ITO films on the conductivity, optical transition type and energy band structure was observed. A simplified film system model with a square potential for surface morphology was employed to explain the difference of conductivity. The energy band structures were also calculated based on the theory of amorphous semiconductor. The conclusion demonstrated the width of optical band gap, as well as the relative position of the Fermi level and mobility edge, which can easily be extended to the band structure determination of other transparent conductive films.

  3. Best Entry Points for Structured Document Retrieval - Part II: Types, Usage and Effectiveness

    DEFF Research Database (Denmark)

    Reid, Jane; Lalmas, Mounia; Finesilver, Karen

    2006-01-01

    Structured document retrieval makes use of document components as the basis of the retrieval process, rather than complete documents. The inherent relationships between these components make it vital to support users' natural browsing behaviour in order to offer effective and efficient access...... to structured documents. This paper examines the concept of best entry points, which are document components from which the user can browse to obtain optimal access to relevant document components. It investigates at the types of best entry points in structured document retrieval, and their usage...

  4. Tangshen Formula Attenuates Colonic Structure Remodeling in Type 2 Diabetic Rats

    DEFF Research Database (Denmark)

    Chen, Pengmin; Zhao, Jingbo; Zhang, Haojun

    2017-01-01

    Aim. This study investigated the effect and mechanism of the Chinese herbal medicine Tangshen Formula (TSF) on GI structure remodeling in the rat model of diabetes. Methods. Type 2 diabetic rats were used. Wet weight per unit length, layer thicknesses, levels of collagens I and III, nuclear factor...

  5. Structure cristalline de type alluaudite KNa5Mn3(MoO46

    Directory of Open Access Journals (Sweden)

    Chahira Bouzidi

    2015-01-01

    Full Text Available The new phase potassium pentasodium trimanganese hexakis(molybdate, KNa5Mn3Mo6O24, has been synthesized using solid-state methods. The structure is composed of M2O10 (M = Mn, Na dimers and MoO4 tetrahedra (point group symmetry 2 sharing corners and forming layers parallel to (100, which are linked via common corners of another type of MO4 tetrahedra, forming a three-dimensional structure with two types of large channels along [001] in which two types of Na+ cations (one with site symmetry 2, one with -1 and K+ cations (site symmetry 2, half-occupation are located. Mn2+ and the third type of Na+ cations are located at the same site M with occupancies of 0.75 and 0.25, respectively. A comparative structural description is provided between the structure of the title compound and those of the related phases Cu1.35Fe3(PO43 and NaAgFeMn2(PO43.

  6. Insect-inspired wing actuation structures based on ring-type resonators

    NARCIS (Netherlands)

    Bolsman, C.T.; Goosen, J.F.L.; Van Keulen, F.

    2008-01-01

    In this paper, we illustrate and study the opportunities of resonant ring type structures as wing actuation mechanisms for a flapping wing Micro Air Vehicle (MAV). Various design alternatives are presented and studied based on computational and physical models. Insects provide an excellent source of

  7. An Investigation of Structure, Flexibility, and Function Variables that Discriminate Asymptomatic Foot Types.

    Science.gov (United States)

    Shultz, Sarah P; Song, Jinsup; Kraszewski, Andrew P; Hafer, Jocelyn F; Rao, Smita; Backus, Sherry; Hillstrom, Rajshree M; Hillstrom, Howard J

    2017-07-01

    It has been suggested that foot type considers not only foot structure (high, normal, low arch), but also function (overpronation, normal, oversupination) and flexibility (reduced, normal, excessive). Therefore, this study used canonical regression analyses to assess which variables of foot structure, function, and flexibility can accurately discriminate between clinical foot type classifications. The feet of 61 asymptomatic, healthy adults (18-77 years) were classified as cavus (N = 24), rectus (N = 54), or planus (N = 44) using standard clinical measures. Custom jigs assessed foot structure and flexibility. Foot function was assessed using an emed-x plantar pressure measuring device. Canonical regression analyses were applied separately to extract essential structure, flexibility, and function variables. A third canonical regression analysis was performed on the extracted variables to identify a combined model. The initial combined model included 30 extracted variables; however 5 terminal variables (malleolar valgus index, arch height index while sitting, first metatarsophalangeal joint laxity while standing, pressure-time integral and maximum contact area of medial arch) were able to correctly predict 80.7% of foot types. These remaining variables focused on specific foot characteristics (hindfoot alignment, arch height, midfoot mechanics, Windlass mechanism) that could be essential to discriminating foot type.

  8. Fabrication Challenges for Realization of Wet Etching Based Comb Type Capacitive Microaccelerometer Structure

    Directory of Open Access Journals (Sweden)

    Shankar DUTTA

    2009-12-01

    Full Text Available The current paper presents fabrication of wet etching based comb-type microaccelerometer structure consisting of 47 interdigitated fingers attached to a large proof mass, which is suspended by two narrow torsional beams. Silicon (, p-type was oxidized and the microaccelerometer structure was patterned by photolithography. Desired device thickness was achieved by combination of wet anisotropic etching of 15μm depth and formation of 12 μm thick p++ etch stop layer. Pits of 15 μm were formed in Pyrex glass and metallic lines with bonding pads were formed by UHV Ti-Au metallization and pattern plating (Au. Patterned glass and silicon wafers were aligned and anodically bonded; whereas, the metallic lines and the microaccelerometer anchors are eutectically bonded. Finally, the suspended comb-type device structure consisting of two torsional beams of 5μm width and interdigitated comb fingers of 10μm width is achieved by Dissolve Wafer Process (DWP. The paper highlights the fabrication challenges faced during the realization of the comb-type structure.

  9. Structural asymmetry between the hips and its relation to experimental fracture type.

    Science.gov (United States)

    Thevenot, Jérôme; Pulkkinen, Pasi; Kuhn, Volker; Eckstein, Felix; Jämsä, Timo

    2010-09-01

    Experimental analysis with paired femurs provides the opportunity to study within-person differences in fracture type and associated structural side differences. We hypothesized that different fracture types in the hips of a subject are associated with structural asymmetry. Bone mineral density (BMD) and structural measurements of paired cadaver femurs (32 females, 24 males) were performed before mechanical testing in a side-impact configuration. Fractures were classified (cervical or trochanteric) and differences in structural parameters, BMD, and failure load were evaluated between the left and right hips as well as between experimental fracture types. We observed larger dimensions (P hip than in the right. Seventeen pairs (30.4%) had trochanteric fractures on one side and cervical on the contralateral side. The asymmetric trochanteric fracture side had a higher head/neck diameter ratio (HD/ND) (P cervical side in females and a lower HD and higher FSD (P fracture cases displayed lower NSA (P cervical ones. In males, asymmetric fracture cases showed larger dimensions than the other groups (P cervical to asymmetric and then to symmetric trochanteric cases (P fracture types. Asymmetry should be considered when using the opposite side as control in clinical studies.

  10. Structural barriers to coping with Type 1 Diabetes Mellitus in Ghana ...

    African Journals Online (AJOL)

    Structural barriers to coping with Type 1 Diabetes Mellitus in Ghana: Experiences of diabetic youth and their families. ... Children and parents noted discrimination and poor care at school. Financial burden was due to the high costs of medications and appliances needed for proper diabetes management. A lack of formal ...

  11. Structural studies on a non toxic homologue of type II RIPs from ...

    Indian Academy of Sciences (India)

    Each domain carries a carbohydrate binding site in type II RIPS of known structure. BGSL has a sugar binding site only on one domain, thus impairing its interaction at the cell surface. The adenine binding site in the catalytic chain is defective. Thus, defects in sugar binding as well as adenine binding appear to contribute to ...

  12. Resolution of multiple sheet-type structures in self-potential ...

    Indian Academy of Sciences (India)

    is used for the optimization of model param- eters of a sheet-type structure. The VFSA is more efficient than conventional SA approach in terms of less CPU time, memory and resolu- tion (Ingber and Rosen 1992). The approach has been used by various scientists for interpretation of different geophysical data (Zhao et al.

  13. Synthesis, structure and ionic conductivity in scheelite type Li 0.5 Ce ...

    Indian Academy of Sciences (India)

    ... with the magnitude of ionic conductivity being two (in the high temperature regime) to one order (in the low temperature regime) lower than the unsubstituted compound. Since these scheelite type structures show significant conductivity, the series of compounds could serve in high temperature lithium battery operations.

  14. Observation of Current Structures at Type-III ELM Onset on EAST

    DEFF Research Database (Denmark)

    Yan, Ning; Naulin, Volker; Xu, G.

    In far scrape-o layer (SOL), alternating negative and positive burst structures in ion saturation current were detected at the onset of each type-III edge localized mode (ELM) on EAST. Different from the fast streaming phenomenon reported previously, one subsequent positive burst structure appears...... structure. To verify the current characteristic of this structure, a mono-polar current filaments model was involved, which can reproduce same pattern commendably. Thus, current transport may dominant in transitional stage and plays an important role in the nonlinear development phase of ELM exhaustive...... crash. As current structure can only be observed in far SOL region of EAST, it maybe conceivable to consider the current origin from local condition rather than release from inside of the pedestal. Our observation may potentially provide support evidence for the recent theory prediction that the error...

  15. Multi-method analysis of the internal structure of the Type D Scale-14 (DS14).

    Science.gov (United States)

    Straat, J Hendrik; van der Ark, L Andries; Sijtsma, Klaas

    2012-04-01

    The Type D Scale-14 (DS14) measures distressed (also, Type D) personality by assessing the medium-level trait negative affectivity that encompasses the low-level traits dysphoria, anxiety, and irritability, and the medium-level trait social inhibition that encompasses the low-level traits social discomfort, reticence, and lack of social poise. The literature discusses three different structural models of the DS14. The goal of this study was to investigate which of the three models best describes the internal structure of the DS14. We used three methods to investigate the internal structure of the DS14 items using data collected in representative samples from the Dutch general population (N=3,181). The methods were exploratory factor analysis, confirmatory factor analysis, and Mokken scale analysis. Exploratory factor analysis suggested a two-factor structure without evidence of the low-level factors, and the other two methods showed evidence of a three-level structure including the low-level factors. A two-factor model with correlated errors for items defining low-level traits adequately describes the data. The results support the three-level hierarchical model as a conceptual model for Type D personality, and support the interpretation of DS14 scores on item subsets representing medium-level traits and low-level traits. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Structural factors that control conformational transitions and serotype specificity in type 3 poliovirus.

    Science.gov (United States)

    Filman, D J; Syed, R; Chow, M; Macadam, A J; Minor, P D; Hogle, J M

    1989-01-01

    The three-dimensional structure of the Sabin strain of type 3 poliovirus has been determined at 2.4 A resolution. Significant structural differences with the Mahoney strain of type 1 poliovirus are confined to loops and terminal extensions of the capsid proteins, occur in all of the major antigenic sites of the virion and typically involve insertions, deletions or the replacement of prolines. Several newly identified components of the structure participate in assembly-dependent interactions which are relevant to the biologically important processes of viral assembly and uncoating. These include two sites of lipid substitution, two putative nucleotides and a beta sheet formed by the N-termini of capsid proteins VP4 and VP1. The structure provides an explanation for the temperature sensitive phenotype of the P3/Sabin strain. Amino acids that regulate temperature sensitivity in type 3 poliovirus are located in the interfaces between promoters, in the binding site for a lipid substituent and in an assembly-dependent extended beta sheet that stabilizes the association of pentamers. Several lines of evidence indicate that these structural components also control conformational transitions at various stages of the viral life cycle. Images PMID:2548847

  17. Structural characterization of outer membrane components of the type IV pili system in pathogenic Neisseria.

    Directory of Open Access Journals (Sweden)

    Samta Jain

    Full Text Available Structures of the type IV pili secretin complexes from Neisseria gonorrhoeae and Neisseria meningitidis, embedded in outer membranes were investigated by transmission electron microscopy. Single particle averaging revealed additional domains not observed previously. Secretin complexes of N. gonorrhoeae showed a double ring structure with a 14-15-fold symmetry in the central ring, and a 14-fold symmetry of the peripheral ring with 7 spikes protruding. In secretin complexes of N. meningitidis, the spikes were absent and the peripheral ring was partly or completely lacking. When present, it had a 19-fold symmetry. The structures of the complexes in several pil mutants were determined. Structures obtained from the pilC1/C2 adhesin and the pilW minor pilin deletion strains were similar to wild-type, whereas deletion of the homologue of N. meningitidis PilW resulted in the absence of secretin structures. Remarkably, the pilE pilin subunit and pilP lipoprotein deletion mutants showed a change in the symmetry of the peripheral ring from 14 to 19 and loss of spikes. The pilF ATPase mutant also lost the spikes, but maintained 14-fold symmetry. These results show that secretin complexes contain previously unidentified large and flexible extra domains with a probable role in stabilization or assembly of type IV pili.

  18. Structural, electronic and magnetic properties of chevron-type graphene, BN and BC2N nanoribbons

    Science.gov (United States)

    Guerra, T.; Azevedo, S.; Kaschny, J. R.

    2017-04-01

    Graphene nanoribbons are predicted to be essential components in future nanoelectronics. The size, edge type, arrangement of atoms and width of nanoribbons drastically change their properties. Boronnitrogencarbon nanoribbons properties are not fully understood so far. In the present contribution it was investigated the structural, electronic and magnetic properties of chevron-type carbon, boron nitride and BC2N nanoribbons, using first-principles calculations. The results indicate that the structural stability is closely related to the discrepancies in the bond lengths, which can induce structural deformations and stress. Such nanoribbons present a wide range of electronic behaviors, depending on their composition and particularities of the atomic arrangement. A net magnetic moment is found for structures that present carbon atoms at the nanoribbon borders. Nevertheless, the calculated magnetic moment depends on the peculiarities of the symmetric arrangement of atoms and imbalance of carbon atoms between different sublattices. It was found that all structures which have a significant energy gap do not present magnetic moment, and vice-versa. Such result indicates the strong correlation between the electronic and magnetic properties of the chevron-type nanoribbons.

  19. Insights into the Mechanism of Type I Dehydroquinate Dehydratases from Structures of Reaction Intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Light, Samuel H.; Minasov, George; Shuvalova, Ludmilla; Duban, Mark-Eugene; Caffrey, Michael; Anderson, Wayne F.; Lavie, Arnon (NWU); (UIC)

    2012-02-27

    The biosynthetic shikimate pathway consists of seven enzymes that catalyze sequential reactions to generate chorismate, a critical branch point in the synthesis of the aromatic amino acids. The third enzyme in the pathway, dehydroquinate dehydratase (DHQD), catalyzes the dehydration of 3-dehydroquinate to 3-dehydroshikimate. We present three crystal structures of the type I DHQD from the intestinal pathogens Clostridium difficile and Salmonella enterica. Structures of the enzyme with substrate and covalent pre- and post-dehydration reaction intermediates provide snapshots of successive steps along the type I DHQD-catalyzed reaction coordinate. These structures reveal that the position of the substrate within the active site does not appreciably change upon Schiff base formation. The intermediate state structures reveal a reaction state-dependent behavior of His-143 in which the residue adopts a conformation proximal to the site of catalytic dehydration only when the leaving group is present. We speculate that His-143 is likely to assume differing catalytic roles in each of its observed conformations. One conformation of His-143 positions the residue for the formation/hydrolysis of the covalent Schiff base intermediates, whereas the other conformation positions the residue for a role in the catalytic dehydration event. The fact that the shikimate pathway is absent from humans makes the enzymes of the pathway potential targets for the development of non-toxic antimicrobials. The structures and mechanistic insight presented here may inform the design of type I DHQD enzyme inhibitors.

  20. Lexicographical structuring: the number and types of fields, data distribution, searching and data presentation

    DEFF Research Database (Denmark)

    Bergenholtz, Henning; Pedersen, Heidi Agerbo

    2015-01-01

    in an existing dictionary. This part of the lexicographical work is what we call structuring, which encompasses a number of various lexicographical decisions. One of these is choosing the fields that a database should contain. Typically, for some of these field types, it will be easy to distribute data......, but for other fields it will require long considerations as there are several distribution options with different outcomes of varying usefulness. A second type of lexicographical decision to be made by the lexicographer is the predefined searching, which involves in what order searches are to be made...... dictionaries. However, only by producing monofunctional dictionaries is it possible to avoid the type of information overload, which makes polyfunctional dictionaries close to useless on electronic devices such as tablets and smartphones. In the case of monofunctional dictionaries, lexicographical structuring...

  1. Visualization and Analyses of Jet Structures from a Cluster-Type Linear Aerospike Nozzle

    Science.gov (United States)

    Niimi, Tomohide; Mori, Hideo; Okabe, Kazuki; Masai, Yusuke; Taniguchi, Mashio

    Aerospike nozzles have been expected as a candidate for an engine of reusable space shuttles to respond to growing demand for rocket-launching and its cost reduction. In this study, the flow field structure in any cross sections around the linear-type aerospike nozzle are visualized and analyzed, using laser induced fluorescence (LIF) of NO seeded in the carrier gas N2. Since the flow field structure is affected mainly by the pressure ratio (P/P), the linear-type aerospike nozzle is set inside the vacuum chamber to carry out the experiments in the wide range of pressure ratios from 75 to 250. Flow fields are visualized in several cross-sections, demonstrating the complicated three-dimensional flow field structures. Pressure sensitive paint (PSP) of PtTFPP bound by poly(TMSP) is also applied successfully to measurement of the complicated pressure distribution on the spike surface.

  2. Simple assembly type solar cell structural unit. Kan prime i kumitate gata taiyo denchi kozotai

    Energy Technology Data Exchange (ETDEWEB)

    Sano, H. (Canon Inc., Tokyo (Japan))

    1990-05-23

    In a solar cell structure with conventional type of connectors, connector cover is in the form of a sheet, which has a demerit of difficulty in multi-cycle switching because,once removed, an insulation material is required to fill the gap when the wire is to be cut. This invention aims to realize an easy assembly type solar cell structure wherein the connection of numerous solar cell elements and the multiple switching of combinations can be flexibly realized. In other word, it is featured by that a solar cell element, plural external connectors to take the genearted power out of the element, and a means of switching the power from the solar cell element are contained in one vessel. By this arrangement, it is possible to construct a solar cell by combining the plural number of the soalr cell structural unit. 5 figs.

  3. Impact of varying soil structure on transport processes in different diagnostic horizons of three soil types.

    Science.gov (United States)

    Kodesová, Radka; Vignozzi, Nadia; Rohosková, Marcela; Hájková, Tereza; Kocárek, Martin; Pagliai, Marcello; Kozák, Josef; Simůnek, Jirka

    2009-02-16

    When soil structure varies in different soil types and the horizons of these soil types, it has a significant impact on water flow and contaminant transport in soils. This paper focuses on the effect of soil structure variations on the transport of pesticides in the soil above the water table. Transport of a pesticide (chlorotoluron) initially applied on soil columns taken from various horizons of three different soil types (Haplic Luvisol, Greyic Phaeozem and Haplic Cambisol) was studied using two scenarios of ponding infiltration. The highest infiltration rate and pesticide mobility were observed for the Bt(1) horizon of Haplic Luvisol that exhibited a well-developed prismatic structure. The lowest infiltration rate was measured for the Bw horizon of Haplic Cambisol, which had a poorly developed soil structure and a low fraction of large capillary pores and gravitational pores. Water infiltration rates were reduced during the experiments by a soil structure breakdown, swelling of clay and/or air entrapped in soil samples. The largest soil structure breakdown and infiltration decrease was observed for the Ap horizon of Haplic Luvisol due to the low aggregate stability of the initially well-aggregated soil. Single-porosity and dual-permeability (with matrix and macropore domains) flow models in HYDRUS-1D were used to estimate soil hydraulic parameters via numerical inversion using data from the first infiltration experiment. A fraction of the macropore domain in the dual-permeability model was estimated using the micro-morphological images. Final soil hydraulic parameters determined using the single-porosity and dual-permeability models were subsequently used to optimize solute transport parameters. To improve numerical inversion results, the two-site sorption model was also applied. Although structural changes observed during the experiment affected water flow and solute transport, the dual-permeability model together with the two-site sorption model proved to be

  4. Crystalline and structural properties of acid-modified lotus rhizome C-type starch.

    Science.gov (United States)

    Cai, Jinwen; Cai, Canhui; Man, Jianmin; Yang, Yang; Zhang, Fengmin; Wei, Cunxu

    2014-02-15

    The crystalline and structural properties of acid-modified C-type starch from lotus rhizomes were investigated using a combination of techniques. The degradation of granule during hydrolysis began from the end distant from the hilum and then propagated into the center of granule, accompanied by loss of birefringence. The crystallinity changed from C-type to A-type via CA-type during hydrolysis. At the early stage of hydrolysis, the amylose content substantially reduced, the peak and conclusion gelatinization temperatures increased, and the enthalpy decreased. During hydrolysis, the double helix content gradually increased and the amorphous component decreased, the lamellar peak intensity firstly increased and then decreased accompanied by hydrolysis of amorphous and crystalline regions. This study elucidated that B-type allomorph was mainly arranged in the distal region of eccentric hilum, A-type allomorph was mainly located in the periphery of hilum end, and the center of granule was a mixed distribution of A- and B-type allomorphs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. The thermodynamic and structural properties of metallocenes-type random ethylene copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Simanke, Adriane G.; Mauler, Raquel S.; Galland, Griselda B. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Quimica]. E-mail: asimanke@portoweb.com.br; Alamo, Rufina G. [Florida State Univ., Tallahassee, FL (UNited States). College of Engineering. Dept. of Chemical Engineering]. E-mail: alamo@eng.fsu.edu

    2001-07-01

    The properties of a series of random ethylene copolymers prepared with the metallocenes catalytic system rac-Et[Ind]{sub 2} ZrCl{sub 2}/MAO were studied for a large variety of comonomer types. These include the classical 1-alkene type with length up to 10 carbons and those of the cyclic type such as cyclopentadiene and dicyclopentadiene. Under rapid crystallization, the melting temperatures of the newly synthesized copolymers followed the relation of model random copolymers indicating a behavior that conforms to that predicted by Flory's phase equilibrium theory. The molar entropy of fusion is not significantly altered by the comonomer type including the dicyclopentadiene type. All types of comonomers studied showed, for a fixed comonomer content, the same change in properties during annealing, except the ethylene 1-butenes. These latter copolymers and the hydrogenated poly butadiene showed a faster rate of change in thermal properties. This is consistent with a higher molecular diffusion for the butene comonomer than for the rest of comonomers analyzed. The properties of the inter lamellar region were also studied as a function of comonomer type and content following the variation of the amorphous halo extracted from the WAXS diffractograms. The observed systematic decrease in the peak scattering angle with increasing comonomer content indicates a variation of the intermolecular liquid structure. (author)

  6. Biophysical investigation of type A PutAs reveals a conserved core oligomeric structure

    Energy Technology Data Exchange (ETDEWEB)

    Korasick, David A. [Department of Biochemistry, University of Missouri, Columbia MO USA; Singh, Harkewal [Department of Chemistry, University of Missouri, Columbia MO USA; Pemberton, Travis A. [Department of Chemistry, University of Missouri, Columbia MO USA; Luo, Min [Department of Chemistry, University of Missouri, Columbia MO USA; Dhatwalia, Richa [Department of Chemistry, University of Missouri, Columbia MO USA; Tanner, John J. [Department of Biochemistry, University of Missouri, Columbia MO USA; Department of Chemistry, University of Missouri, Columbia MO USA

    2017-08-01

    Many enzymes form homooligomers, yet the functional significance of self-association is seldom obvious. Herein, we examine the connection between oligomerization and catalytic function for proline utilization A (PutA) enzymes. PutAs are bifunctional enzymes that catalyze both reactions of proline catabolism. Type A PutAs are the smallest members of the family, possessing a minimal domain architecture consisting of N-terminal proline dehydrogenase and C-terminal l-glutamate-γ-semialdehyde dehydrogenase modules. Type A PutAs form domain-swapped dimers, and in one case (Bradyrhizobium japonicum PutA), two of the dimers assemble into a ring-shaped tetramer. Whereas the dimer has a clear role in substrate channeling, the functional significance of the tetramer is unknown. To address this question, we performed structural studies of four-type A PutAs from two clades of the PutA tree. The crystal structure of Bdellovibrio bacteriovorus PutA covalently inactivated by N-propargylglycine revealed a fold and substrate-channeling tunnel similar to other PutAs. Small-angle X-ray scattering (SAXS) and analytical ultracentrifugation indicated that Bdellovibrio PutA is dimeric in solution, in contrast to the prediction from crystal packing of a stable tetrameric assembly. SAXS studies of two other type A PutAs from separate clades also suggested that the dimer predominates in solution. To assess whether the tetramer of B. japonicum PutA is necessary for catalytic function, a hot spot disruption mutant that cleanly produces dimeric protein was generated. The dimeric variant exhibited kinetic parameters similar to the wild-type enzyme. These results implicate the domain-swapped dimer as the core structural and functional unit of type A PutAs.

  7. Possibility of comb-type rf shield structure for high-current accelerators

    Directory of Open Access Journals (Sweden)

    Y. Suetsugu

    2003-10-01

    Full Text Available A novel rf shield structure for bellows chambers or gate valves in high-current accelerators is proposed. The rf shield has no thin fingers, but nested comb teeth instead at the inner surface of the beam duct. The comb-type rf shield has a higher thermal strength structurally than the conventional finger-type one. A simulation also indicates its lower impedance. Especially, the leak of a TE modelike higher order mode through the axial slits, which causes mainly heating of these components, is almost suppressed due to thick teeth. An abrasion test in a vacuum using a test piece of the comb-type rf shield shows less dust generation compared to the finger type. Another preliminary test transmitting 508 MHz microwaves through a prototype rf shield in the atmosphere found no abnormal heating or arcing. A trial model of bellows chambers with the comb-type rf shield will be installed and tested using a real beam in the KEK B-factory positron ring this year.

  8. Structural Variation of Type I-F CRISPR RNA Guided DNA Surveillance.

    Science.gov (United States)

    Pausch, Patrick; Müller-Esparza, Hanna; Gleditzsch, Daniel; Altegoer, Florian; Randau, Lennart; Bange, Gert

    2017-08-17

    CRISPR-Cas systems are prokaryotic immune systems against invading nucleic acids. Type I CRISPR-Cas systems employ highly diverse, multi-subunit surveillance Cascade complexes that facilitate duplex formation between crRNA and complementary target DNA for R-loop formation, retention, and DNA degradation by the subsequently recruited nuclease Cas3. Typically, the large subunit recognizes bona fide targets through the PAM (protospacer adjacent motif), and the small subunit guides the non-target DNA strand. Here, we present the Apo- and target-DNA-bound structures of the I-Fv (type I-F variant) Cascade lacking the small and large subunits. Large and small subunits are functionally replaced by the 5' terminal crRNA cap Cas5fv and the backbone protein Cas7fv, respectively. Cas5fv facilitates PAM recognition from the DNA major groove site, in contrast to all other described type I systems. Comparison of the type I-Fv Cascade with an anti-CRISPR protein-bound I-F Cascade reveals that the type I-Fv structure differs substantially at known anti-CRISPR protein target sites and might therefore be resistant to viral Cascade interception. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Crystal structure of the Yersinia type III secretion protein YscE

    Energy Technology Data Exchange (ETDEWEB)

    Phan, Jason; Austin, Brian P.; Waugh, David S. (NIH)

    2010-12-06

    The plague-causing bacterium Yersinia pestis utilizes a contact-dependent (type III) secretion system (T3SS) to transport virulence factors from the bacterial cytosol directly into the interior of mammalian cells where they interfere with signal transduction pathways that mediate phagocytosis and the inflammatory response. The type III secretion apparatus is composed of 20-25 different Yersinia secretion (Ysc) proteins. We report here the structure of YscE, the smallest Ysc protein, which is a dimer in solution. The probable mode of oligomerization is discussed.

  10. Ground-based and spaceborn observations of the type II burst with developed fine structure

    Science.gov (United States)

    Dorovskyy, V.; Melnik, V.; Konovalenko, A.; Brazhenko, A.; Rucker, H.; Stanislavskyy, A.; Panchenko, M.

    2012-09-01

    The combination of two huge ground-based radio telescopes (UTR-2 and URAN-2) operated in decameter wavelengths with three spatially separated spacecrafts (SOHO, STEREO-A and STEREO-B) equipped with white light coronagraphs, UV telescopes and decameter-hectometer band radio telescopes created a unique opportunity to investigate the high energy solar transients, such as CMEs and their manifestations in radio bands - type II bursts. In this paper we made detailed analysis of the powerful and complex event occurred on 7 June 2011 consisted of Halo-CME and type II burst with rich fine structure.

  11. Adaptive fuzzy logic controller with direct action type structures for InnoSAT attitude control system

    Science.gov (United States)

    Bakri, F. A.; Mashor, M. Y.; Sharun, S. M.; Bibi Sarpinah, S. N.; Abu Bakar, Z.

    2016-10-01

    This study proposes an adaptive fuzzy controller for attitude control system (ACS) of Innovative Satellite (InnoSAT) based on direct action type structure. In order to study new methods used in satellite attitude control, this paper presents three structures of controllers: Fuzzy PI, Fuzzy PD and conventional Fuzzy PID. The objective of this work is to compare the time response and tracking performance among the three different structures of controllers. The parameters of controller were tuned on-line by adjustment mechanism, which was an approach similar to a PID error that could minimize errors between actual and model reference output. This paper also presents a Model References Adaptive Control (MRAC) as a control scheme to control time varying systems where the performance specifications were given in terms of the reference model. All the controllers were tested using InnoSAT system under some operating conditions such as disturbance, varying gain, measurement noise and time delay. In conclusion, among all considered DA-type structures, AFPID controller was observed as the best structure since it outperformed other controllers in most conditions.

  12. Analysis of offshore platforms lifting with fixed pile structure type (fixed platform) based on ASD89

    Science.gov (United States)

    Sugianto, Agus; Indriani, Andi Marini

    2017-11-01

    Platform construction GTS (Gathering Testing Sattelite) is offshore construction platform with fix pile structure type/fixed platform functioning to support the mining of petroleum exploitation. After construction fabrication process platform was moved to barges, then shipped to the installation site. Moving process is generally done by pull or push based on construction design determined when planning. But at the time of lifting equipment/cranes available in the work area then the moving process can be done by lifting so that moving activity can be implemented more quickly of work. This analysis moving process of GTS platform in a different way that is generally done to GTS platform types by lifting using problem is construction reinforcement required, so the construction can be moved by lifting with analyzing and checking structure working stress that occurs due to construction moving process by lifting AISC code standard and analysis using the SAP2000 structure analysis program. The analysis result showed that existing condition cannot be moved by lifting because stress ratio is above maximum allowable value that is 0.950 (AISC-ASD89). Overstress occurs on the member 295 and 324 with stress ratio value 0.97 and 0.95 so that it is required structural reinforcement. Box plate aplication at both members so that it produces stress ratio values 0.78 at the member 295 and stress ratio of 0.77 at the member 324. These results indicate that the construction have qualified structural reinforcement for being moved by lifting.

  13. Cryo-EM studies of the structure and dynamics of vacuolar-type ATPases.

    Science.gov (United States)

    Mazhab-Jafari, Mohammad T; Rubinstein, John L

    2016-07-01

    Electron cryomicroscopy (cryo-EM) has significantly advanced our understanding of molecular structure in biology. Recent innovations in both hardware and software have made cryo-EM a viable alternative for targets that are not amenable to x-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. Cryo-EM has even become the method of choice in some situations where x-ray crystallography and NMR spectroscopy are possible but where cryo-EM can determine structures at higher resolution or with less time or effort. Rotary adenosine triphosphatases (ATPases) are crucial to the maintenance of cellular homeostasis. These enzymes couple the synthesis or hydrolysis of adenosine triphosphate to the use or production of a transmembrane electrochemical ion gradient, respectively. However, the membrane-embedded nature and conformational heterogeneity of intact rotary ATPases have prevented their high-resolution structural analysis to date. Recent application of cryo-EM methods to the different types of rotary ATPase has led to sudden advances in understanding the structure and function of these enzymes, revealing significant conformational heterogeneity and characteristic transmembrane α helices that are highly tilted with respect to the membrane. In this Review, we will discuss what has been learned recently about rotary ATPase structure and function, with a particular focus on the vacuolar-type ATPases.

  14. Fourier transform infrared microspectroscopic analysis of the effects of cereal type and variety within a type of grain on structural makeup in relation to rumen degradation kinetics.

    Science.gov (United States)

    Walker, Amanda M; Yu, Peiqiang; Christensen, Colleen R; Christensen, David A; McKinnon, John J

    2009-08-12

    The objectives of this study were to use Fourier transform infrared microspectroscopy (FTIRM) to determine structural makeup (features) of cereal grain endosperm tissue and to reveal and identify differences in protein and carbohydrate structural makeup between different cereal types (corn vs barley) and between different varieties within a grain (barley CDC Bold, CDC Dolly, Harrington, and Valier). Another objective was to investigate how these structural features relate to rumen degradation kinetics. The items assessed included (1) structural differences in protein amide I to nonstructural carbohydrate (NSC, starch) intensity and ratio within cellular dimensions; (2) molecular structural differences in the secondary structure profile of protein, alpha-helix, beta-sheet, and their ratio; (3) structural differences in NSC to amide I ratio profile. From the results, it was observed that (1) comparison between grain types [corn (cv. Pioneer 39P78) vs barley (cv. Harrington)] showed significant differences in structural makeup in terms of NSC, amide I to NSC ratio, and rumen degradation kinetics (degradation ratio, effective degradability of dry matter, protein and NSC) (P makeup in terms of amide I, NSC, amide I to NSC ratio, alpha-helix and beta-sheet protein structures, and rumen degradation kinetics (effective degradability of dry matter, protein, and NSC) (P makeup differences between cereal types and between different varieties within a type of grain could be revealed. These structural makeup differences were related to the rate and extent of rumen degradation.

  15. Paired structures, imprecision types and two-level knowledge representation by means of opposites

    DEFF Research Database (Denmark)

    Rodríguez, J. Tinguaro; Franco de los Ríos, Camilo; Gómez, Daniel

    2016-01-01

    Opposition-based models are a current hot-topic in knowledge representation. The point of this paper is to suggest that opposition can be in fact introduced at two different levels, those of the predicates of interest being represented (as short/tall) and of the logical references (true/false) used...... to evaluate the verification of the former. We study this issue by means of the consideration of different paired structures at each level. We also pay attention at how different types of fuzziness may be introduced in these paired structures to model imprecision and lack of knowledge. As a consequence, we...

  16. Prediction, conservation analysis, and structural characterization of mammalian mucin-type O-glycosylation sites

    DEFF Research Database (Denmark)

    Julenius, Karin; Mølgaard, Anne; Gupta, Ramneek

    2004-01-01

    than a nonglycosylated one. The Protein Data Bank was analyzed for structural information, and 12 glycosylated structures were obtained. All positive sites were found in coil or turn regions. A method for predicting the location for mucin-type glycosylation sites was trained using a neural network...... approach. The best overall network used as input amino acid composition, averaged surface accessibility predictions together with substitution matrix profile encoding of the sequence. To improve prediction on isolated (single) sites, networks were trained on isolated sites only. The final method combines...

  17. Prediction, conservation analysis, and structural characterization of mammalian mucin-type O-glycosylation sites

    DEFF Research Database (Denmark)

    Julenius, Karin; Mølgaard, Anne; Gupta, Ramneek

    2005-01-01

    than a nonglycosylated one. The Protein Data Bank was analyzed for structural information, and 12 glycosylated structures were obtained. All positive sites were found in coil or turn regions. A method for predicting the location for mucin-type glycosylation sites was trained using a neural network...... approach. The best overall network used as input amino acid composition, averaged surface accessibility predictions together with substitution matrix profile encoding of the sequence. To improve prediction on isolated (single) sites, networks were trained on isolated sites only. The final method combines...

  18. Structural and evolutionary aspects of algal blue light receptors of the cryptochrome and aureochrome type.

    Science.gov (United States)

    Essen, Lars-Oliver; Franz, Sophie; Banerjee, Ankan

    2017-10-01

    Blue-light reception plays a pivotal role for algae to adapt to changing environmental conditions. In this review we summarize the current structural and mechanistic knowledge about flavin-dependent algal photoreceptors. We especially focus on the cryptochrome and aureochrome type photoreceptors in the context of their evolutionary divergence. Despite similar photochemical characteristics to orthologous photoreceptors from higher plants and animals the algal blue-light photoreceptors have developed a set of unique structural and mechanistic features that are summarized below. Copyright © 2017 Elsevier GmbH. All rights reserved.

  19. Structure of comorbid psychopathological disorders in patients with type 2nd diabetes mellitus

    Directory of Open Access Journals (Sweden)

    V. V. Chugunov

    2017-04-01

    Full Text Available Aim: to identify and explore the structure of comorbid psychopathological disorders in patients with type 2nd diabetes mellitus (DM. Materials and methods: 543 patients with type 2nd DM were included into the study. The average age of patients was (56.2 ± 0.65 years. The patients were divided into three groups according to the severity of DM. The first clinical group (CG-1 included 57 patients with type 2nd DM of mild severity, who was treated in outpatient department; the average age in the group was (51.8 ± 1.28 years. The second clinical group (CG-2 made up of 312 patients with type 2nd DM, moderate severity, they were in inpatient department; the median age of the group was (55.1 ± 1.12 years. The third clinical group (CG-3 included 174 patients with type 2nd DM, severe degrees of severity, they undergone inpatient treatment too; average age in the group was (61.8 ± 0.85 years. Research methods: clinical-anamnesis, clinical- psychopathological, statistical. Research results. The study established the incidence of non-psychotic mental disorders of varying severity in patients with type 2nd DM at the level of 94.11 %, among them, for 91.16 % – of psychogenic origin. Proportional correlation between the severity of type 2nd DM and the absence of comorbid psychopathological manifestations was detected (rs = -0.3416, p < 0.01. It is revealed that the dominant psychopathological syndromes among all patients with type 2nd DM were psychoorganic (62.43 %, dyssomnia (60.86 %, asthenic (55.58 % and anxiety (43.05 % syndromes. Structure of the dominant psychopathological syndromes was established depending on severity of type 2nd DM: in CG-1 dominated dyssomnia (36.84 %, anxiety (31.58 %, psychoorganic (21.05 % syndromes; in CG-2 – psychoorganic (65.38 %, asthenic (40.38 %, dyssomnia (38.46 %, anxiety (37, and 82 % syndromes; in CG-3 – dyssomnia (97.70 %, asthenic (89.08 %, organic mental (70.69 %, anxious 48.28 % syndromes. Significant

  20. The use of impression management tactics in structured interviews: a function of question type?

    Science.gov (United States)

    Ellis, Aleksander P J; West, Bradley J; Ryan, Ann Marie; DeShon, Richard P

    2002-12-01

    This study investigated impression management tactic use during structured interviews containing both experience-based and situational questions. Specifically, the authors examined whether applicants' use of impression management tactics depended on question type. Results from 119 structured interviews indicated that almost all of the applicants used some form of impression management. Significantly more assertive than defensive impression management tactics were used, and among assertive tactics, applicants tended to use self-promotion rather than ingratiation. However, different question types prompted the use of different impression management tactics. Ingratiation tactics were used significantly more when applicants answered situational questions, whereas self-promotion tactics were used significantly more when applicants answered experience-based questions. Furthermore, the use of self-promotion and ingratiation tactics was positively related to interviewer evaluations.

  1. Complex structure of type VI peptidoglycan muramidase effector and a cognate immunity protein

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tianyu [Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ding, Jinjing; Zhang, Ying; Wang, Da-Cheng, E-mail: dcwang@ibp.ac.cn [Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Liu, Wei, E-mail: dcwang@ibp.ac.cn [The Third Military Medical University, Chongqing 400038 (China); Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China)

    2013-10-01

    The structure of the Tse3–Tsi3 complex associated with the bacterial type VI secretion system of P. aeruginosa has been solved and refined at 1.9 Å resolution. The structural basis of the recognition of the muramidase effector and its inactivation by its cognate immunity protein is revealed. The type VI secretion system (T6SS) is a bacterial protein-export machine that is capable of delivering virulence effectors between Gram-negative bacteria. The T6SS of Pseudomonas aeruginosa transports two lytic enzymes, Tse1 and Tse3, to degrade cell-wall peptidoglycan in the periplasm of rival bacteria that are competing for niches via amidase and muramidase activities, respectively. Two cognate immunity proteins, Tsi1 and Tsi3, are produced by the bacterium to inactivate the two antibacterial effectors, thereby protecting its siblings from self-intoxication. Recently, Tse1–Tsi1 has been structurally characterized. Here, the structure of the Tse3–Tsi3 complex is reported at 1.9 Å resolution. The results reveal that Tse3 contains a C-terminal catalytic domain that adopts a soluble lytic transglycosylase (SLT) fold in which three calcium-binding sites were surprisingly observed close to the catalytic Glu residue. The electrostatic properties of the substrate-binding groove are also distinctive from those of known structures with a similar fold. All of these features imply that a unique catalytic mechanism is utilized by Tse3 in cleaving glycosidic bonds. Tsi3 comprises a single domain showing a β-sandwich architecture that is reminiscent of the immunoglobulin fold. Three loops of Tsi3 insert deeply into the groove of Tse3 and completely occlude its active site, which forms the structural basis of Tse3 inactivation. This work is the first crystallographic report describing the three-dimensional structure of the Tse3–Tsi3 effector–immunity pair.

  2. A Structural Study of Delafossite-type CuInO{sub 2} Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, Alan V; Blacklocks, Aran N; Rougier, Aline; Yaicle, Cedric, E-mail: a.v.chadwick@kent.ac.u

    2010-11-01

    This contribution reports a study of the preparation of pure and doped delafossite-type material CuInO{sub 2} using pulsed laser deposition. A series of films have been prepared at different oxygen partial pressures. X-ray absorption spectroscopy (XAS) has been used to characterise the microstructure of the films. The results show that the structure of the films is extremely sensitive to the preparation conditions.

  3. Preparation of axial-type wire-structure crystalline silicon solar cells

    Science.gov (United States)

    Shirayanagi, Yusuke; Yashiki, Yasutoshi; Kato, Shinya; Konagai, Makoto

    2017-08-01

    The fabrication of an axial-type microwire-structure silicon (Si-MW) solar cell has been studied, and it is compared with the radial-type Si-MW solar cell. In this study, a number of microwires were formed on a p-type Si wafer and an n-layer were fabricated on the top region of microwires to form p-n junctions. After that, Si-MWs were filled with an Al1-xOx film, deposited by thermal atomic layer deposition, and silica particles, respectively. Then, the Al1-xOx film and silica particles on the n-layer were removed by chemical mechanical polishing to form an electrical contact with the electrode. As a result, we obtained a conversion efficiency of 8.2% from the axial-type Si-MW solar cell. In addition, compared with a radial-type Si-MW solar cell, a higher quantum efficiency was obtained in the short-wavelength region (300-600 nm) for the axial-type Si-MW solar cell.

  4. Structural characterization of CFA/III and Longus type IVb pili from enterotoxigenic Escherichia coli.

    Science.gov (United States)

    Kolappan, Subramaniapillai; Roos, Justin; Yuen, Alex S W; Pierce, Owen M; Craig, Lisa

    2012-05-01

    The type IV pili are helical filaments found on many Gram-negative pathogenic bacteria, with multiple diverse roles in pathogenesis, including microcolony formation, adhesion, and twitching motility. Many pathogenic enterotoxigenic Escherichia coli (ETEC) isolates express one of two type IV pili belonging to the type IVb subclass: CFA/III or Longus. Here we show a direct correlation between CFA/III expression and ETEC aggregation, suggesting that these pili, like the Vibrio cholerae toxin-coregulated pili (TCP), mediate microcolony formation. We report a 1.26-Å resolution crystal structure of CofA, the major pilin subunit from CFA/III. CofA is very similar in structure to V. cholerae TcpA but possesses a 10-amino-acid insertion that replaces part of the α2-helix with an irregular loop containing a 3(10)-helix. Homology modeling suggests a very similar structure for the Longus LngA pilin. A model for the CFA/III pilus filament was generated using the TCP electron microscopy reconstruction as a template. The unique 3(10)-helix insert fits perfectly within the gap between CofA globular domains. This insert, together with differences in surface-exposed residues, produces a filament that is smoother and more negatively charged than TCP. To explore the specificity of the type IV pilus assembly apparatus, CofA was expressed heterologously in V. cholerae by replacing the tcpA gene with that of cofA within the tcp operon. Although CofA was synthesized and processed by V. cholerae, no CFA/III filaments were detected, suggesting that the components of the type IVb pilus assembly system are highly specific to their pilin substrates.

  5. [Bacterial TEM-type serine beta-lactamases: structure and analysis of mutations].

    Science.gov (United States)

    Grigorenko, V G; Rubtsova, M Yu; Uporov, I V; Ishtubaev, I V; Andreeva, I P; Shcherbinin, D S; Veselovsky, A V; Egorov, A M

    2017-11-01

    Beta-lactamases (EC 3.5.2.6) represent a superfamily containing more than 2,000 members: it includes genetically and functionally different bacterial enzymes capable to destroy the beta-lactam antibiotics. The most common are beta-lactamases of molecular class A with serine in the active center. Among them, TEM-type beta-lactamases are of particular interest from the viewpoint of studying the mechanisms of the evolution of resistance due to their broad polymorphism. To date, more than 200 sequences of TEM-type beta-lactamases have been described and more than 60 structures of different mutant forms have been presented in Protein Data Bank. We have considered the main structural features of the enzymes of this type with particular attention to the analysis of key drug resistance and the secondary mutations, their location relative to the active center and the surface of the protein globule. We have developed the BlaSIDB database (www.blasidb.org) which is an open information resource combining available data on 3D structures, amino acid sequences and nomenclature of the corresponding forms of beta-lactamases.

  6. Fine and Superfine Structure of the Decameter-Hectometer Type II Burst on 7 June 2011

    Science.gov (United States)

    Dorovskyy, V. V.; Melnik, V. N.; Konovalenko, A. A.; Brazhenko, A. I.; Panchenko, M.; Poedts, S.; Mykhaylov, V. A.

    2015-07-01

    The characteristics of a type II burst with a herringbone structure observed both with ground-based radio telescopes (UTR-2 and URAN-2) and space-borne spectrometers (STEREO-A and B) are discussed. The burst was recorded on 7 June 2011 in the frequency band 3 - 33 MHz. It was characterized by extremely rich fine structure. Statistical analysis of more than 300 herringbone sub-bursts constituting the burst was performed separately for the positively (reverse) and negatively (forward) drifting sub-bursts. The sense and the degree of circular polarization of the herringbone sub-bursts were measured in a wide frequency band (16 - 32 MHz). A second-order fine frequency structure of the herringbone sub-bursts was observed and studied for the first time. Using STEREO/COR1 and SOHO/LASCO-C2 images, we determined the direction and radial speed of the coronal mass ejection responsible for the studied type II burst. The possible location of the type II burst source on the flank of the shock was found.

  7. Finite Element Analysis of Doorframe Structure of Single Oblique Pole Type in Container Crane

    Science.gov (United States)

    Cheng, X. F.; Wu, F. Q.; Tang, G.; Hu, X.

    2017-07-01

    Compared with the composite type, the single oblique pole type has more advantages, such as simple structure, thrift steel and high safe overhead clearance. The finite element model of the single oblique pole type is established in nodes by ANSYS, and more details are considered when the model is simplified, such as the section of Girder and Boom, torque in Girder and Boom occurred by Machinery house and Trolley, density according to the way of simplification etc. The stress and deformation of ten observation points are compared and analyzed, when the trolley is in nine dangerous positions. Based on the result of analysis, six dangerous points are selected to provide reference for the detection and evaluation of container crane.

  8. Microcrystalline-Silicon-Oxide-Based N-Type Reflector Structure in Micromorph Tandem Solar Cells

    Directory of Open Access Journals (Sweden)

    Chiung-Nan Li

    2012-01-01

    Full Text Available N-type microcrystalline silicon oxide thin films (n-c-SiO:H have been deposited by VHF-PECVD (40 MHz with reactant gas mixtures of CO2/SiH4 and H2. N-c-SiO thin films exhibiting low refractive index value (n600nm∼2, and medium/high conductivity (≧10−9 S/cm are suitable to be used as an “n-type reflector” in micromorph tandem solar cells. Transmission electron microscopy (TEM results show that microstructures of n-c-SiO:H thin films contain nanocrystalline Si particles, which are randomly embedded in the a-SiO matrix. This specific microstructure provides n-c-SiO:H thin films excellent optoelectronic properties; therefore, n-c-SiO:H thin films are appropriate candidates for “n-type reflector” structures in Si tandem solar cells.

  9. [Soil microbial community structure of two types of forests in the mid-subtropics of China].

    Science.gov (United States)

    Han, Shi-zhong; Gao, Ren; Li, Ai-ping; Ma, Hong-liang; Yin, Yun-feng; Si, You-tao; Chen, Shi-dong; Zheng, Qun-rui

    2015-07-01

    Soil microbial community structures were analyzed by biomarker method of phospholipid fatty acid (PLFA) for a natural forest dominated by Castanopsis fabri (CF) and an adjacent plantation of Cunninghamia lanceolata (CL) in the mid-subtropics of China. The results showed that the amounts of total PLFAs, bacterial PLFAs, fungal PLFAs, gram-positive bacterial PLFAs and gramnegative bacterial PLFAs in the 0-10 cm soil layer were higher than in the 10-20 cm soil layer, and each type of PLFAs in CF were higher than in CL. In either soil layer of the two forest types, the contents of bacterial PLFAs were significantly higher than those of fungal PLFAs. In the two forests, the contents of bacterial PLFAs accounted for 44%-52% of total PLFAs, while the contents of fungal PLFAs just accounted for 6%-8%, indicating the bacteria were dominant in the soils of the two vegetation types. Principal component analysis showed that the influence of vegetation types was greater than soil depth on the microbial community structures. Correlation analysis showed that gram-negative bacterial PLFAs, gram-positive bacterial PLFAs and bacterial PLFAs were significantly negatively correlated with pH, positively with water content, and the PLFAs of main soil microorganism groups were significantly positively correlated with soil total nitrogen, organic carbon, C/N and ammonium.

  10. Structure and operation of the DNA-translocating type I DNA restriction enzymes.

    Science.gov (United States)

    Kennaway, Christopher K; Taylor, James E; Song, Chun Feng; Potrzebowski, Wojciech; Nicholson, William; White, John H; Swiderska, Anna; Obarska-Kosinska, Agnieszka; Callow, Philip; Cooper, Laurie P; Roberts, Gareth A; Artero, Jean-Baptiste; Bujnicki, Janusz M; Trinick, John; Kneale, G Geoff; Dryden, David T F

    2012-01-01

    Type I DNA restriction/modification (RM) enzymes are molecular machines found in the majority of bacterial species. Their early discovery paved the way for the development of genetic engineering. They control (restrict) the influx of foreign DNA via horizontal gene transfer into the bacterium while maintaining sequence-specific methylation (modification) of host DNA. The endonuclease reaction of these enzymes on unmethylated DNA is preceded by bidirectional translocation of thousands of base pairs of DNA toward the enzyme. We present the structures of two type I RM enzymes, EcoKI and EcoR124I, derived using electron microscopy (EM), small-angle scattering (neutron and X-ray), and detailed molecular modeling. DNA binding triggers a large contraction of the open form of the enzyme to a compact form. The path followed by DNA through the complexes is revealed by using a DNA mimic anti-restriction protein. The structures reveal an evolutionary link between type I RM enzymes and type II RM enzymes.

  11. Membrane structure formation induced by two types of banana-shaped proteins

    Science.gov (United States)

    Noguchi, Hiroshi; Fournier, Jean-Baptiste

    The assembly of banana-shaped rodlike proteins on membranes, and the associated membrane shape transformations, are investigated by analytical theory and coarse-grained simulations. The membrane-mediated interactions between two banana-shaped inclusions are derived theoretically using a point-like formalism based on fixed anisotropic curvatures, both for zero surface tension and for finite surface tension. On a larger scale, the interactions between assemblies of such rodlike inclusions are determined analytically. Meshless membrane simulations are performed in the presence of a large number of inclusions of two types, corresponding to curved rods of opposite curvatures, both for flat membranes and vesicles. Rods of the same type aggregate into linear assemblies perpendicular to the rod axis, leading to membrane tubulation. However, rods of the other type, those of opposite curvature, are attracted to the lateral sides of these assemblies, and stabilize a straight bump structure that prevents tubulation. When the two types of rods have almost opposite curvatures, the bumps attract one another, forming a stripe structure. Positive surface tension is found to stabilize the stripe formation. The simulation results agree well with the theoretical predictions provided the point-like curvatures of the model are scaled-down to account for the effective flexibility of the simulated rods.

  12. Field Observation of Joint Structures in Various Types of Igneous Rocks

    Science.gov (United States)

    Kano, Shingo; Tsuchiya, Noriyoshi

    2006-05-01

    In this study, field observations of natural fracture network systems in some intrusive and extrusive rocks were undertaken, to clarify the fracturing mechanism in the rocks. Shallow intrusives, whose depth of emplacement was less than several hundred metres, include the Momo-iwa Dacite dome on Rebun Island (Hokkaido), and Jodogahama Rhyolite in Iwate prefecture. Extrusive complexes studied include the Tojinbo Andesite and Ojima Rhyodacite in Fukui prefecture. Rocks of `granitic' composition were collected from the Takidani (Japan Alps) and Hijiori (Yamagata prefecture) plutons. The joint structure in Hijiori Granite was evaluated by analysis of core samples extracted from the HDR-3 geothermal production well. Based on detailed field observation, joint structures related to thermal contraction of a rock mass could be classified according to their inferred depth of formation. Joints from a near surface setting, such as shallow intrusive rocks and extrusives, tend to form pentagonal — hexagonal columnar structures (for a variety of rock types), whilst granitic rocks (from a deeper setting) typically exhibit a parallelepiped structure. The apparent differences in joint form are inferred to be dependent on the confining pressure, which acts on joint generation and propagation. In cases of non-confining pressure, such as the near-surface (shallow intrusive/extrusive) setting, joint networks typically form a columnar structure. On the contrary, confining pressure is considerably greater for deeper rock masses, and these form a parallelepiped joint structure.

  13. Structure of human POFUT2: insights into thrombospondin type 1 repeat fold and O-fucosylation

    Science.gov (United States)

    Chen, Chun-I; Keusch, Jeremy J; Klein, Dominique; Hess, Daniel; Hofsteenge, Jan; Gut, Heinz

    2012-01-01

    Protein O-fucosylation is a post-translational modification found on serine/threonine residues of thrombospondin type 1 repeats (TSR). The fucose transfer is catalysed by the enzyme protein O-fucosyltransferase 2 (POFUT2) and >40 human proteins contain the TSR consensus sequence for POFUT2-dependent fucosylation. To better understand O-fucosylation on TSR, we carried out a structural and functional analysis of human POFUT2 and its TSR substrate. Crystal structures of POFUT2 reveal a variation of the classical GT-B fold and identify sugar donor and TSR acceptor binding sites. Structural findings are correlated with steady-state kinetic measurements of wild-type and mutant POFUT2 and TSR and give insight into the catalytic mechanism and substrate specificity. By using an artificial mini-TSR substrate, we show that specificity is not primarily encoded in the TSR protein sequence but rather in the unusual 3D structure of a small part of the TSR. Our findings uncover that recognition of distinct conserved 3D fold motifs can be used as a mechanism to achieve substrate specificity by enzymes modifying completely folded proteins of very wide sequence diversity and biological function. PMID:22588082

  14. Universal properties of type IIB and F-theory flux compactifications at large complex structure

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, M.C. David [Department of Applied Mathematics and Theoretical Physics, University of Cambridge,Cambridge, CB3 0WA (United Kingdom); Sousa, Kepa [Instituto de Fisica Teorica UAM-CSIC Universidad Autonoma de Madrid,Cantoblanco, 28049 Madrid (Spain); Department of Theoretical Physics and History of Science,University of the Basque Country UPV/EHU,48080 Bilbao (Spain)

    2016-03-11

    We consider flux compactifications of type IIB string theory and F-theory in which the respective superpotentials at large complex structure are dominated by cubic or quartic terms in the complex structure moduli. In this limit, the low-energy effective theory exhibits universal properties that are insensitive to the details of the compactification manifold or the flux configuration. Focussing on the complex structure and axio-dilaton sector, we show that there are no vacua in this region and the spectrum of the Hessian matrix is highly peaked and consists only of three distinct eigenvalues (0, 2m{sub 3/2}{sup 2} and 8m{sub 3/2}{sup 2}), independently of the number of moduli. We briefly comment on how the inclusion of Kähler moduli affect these findings. Our results generalise those of Brodie & Marsh http://dx.doi.org/10.1007/JHEP01(2016)037, in which these universal properties were found in a subspace of the large complex structure limit of type IIB compactifications.

  15. The extracellular architecture of adherens junctions revealed by crystal structures of type I cadherins.

    Science.gov (United States)

    Harrison, Oliver J; Jin, Xiangshu; Hong, Soonjin; Bahna, Fabiana; Ahlsen, Goran; Brasch, Julia; Wu, Yinghao; Vendome, Jeremie; Felsovalyi, Klara; Hampton, Cheri M; Troyanovsky, Regina B; Ben-Shaul, Avinoam; Frank, Joachim; Troyanovsky, Sergey M; Shapiro, Lawrence; Honig, Barry

    2011-02-09

    Adherens junctions, which play a central role in intercellular adhesion, comprise clusters of type I classical cadherins that bind via extracellular domains extended from opposing cell surfaces. We show that a molecular layer seen in crystal structures of E- and N-cadherin ectodomains reported here and in a previous C-cadherin structure corresponds to the extracellular architecture of adherens junctions. In all three ectodomain crystals, cadherins dimerize through a trans adhesive interface and are connected by a second, cis, interface. Assemblies formed by E-cadherin ectodomains coated on liposomes also appear to adopt this structure. Fluorescent imaging of junctions formed from wild-type and mutant E-cadherins in cultured cells confirm conclusions derived from structural evidence. Mutations that interfere with the trans interface ablate adhesion, whereas cis interface mutations disrupt stable junction formation. Our observations are consistent with a model for junction assembly involving strong trans and weak cis interactions localized in the ectodomain. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. The type of carbohydrates specifically selects microbial community structures and fermentation patterns.

    Science.gov (United States)

    Chatellard, Lucile; Trably, Eric; Carrère, Hélène

    2016-12-01

    The impact on dark fermentation of seven carbohydrates as model substrates of lignocellulosic fractions (glucose, cellobiose, microcrystalline cellulose, arabinose, xylose, xylan and wheat straw) was investigated. Metabolic patterns and bacterial communities were characterized at the end of batch tests inoculated with manure digestate. It was found that hydrogen production was linked to the sugar type (pentose or hexose) and the degree of polymerisation. Hexoses produced less hydrogen, with a specific selection of lactate-producing bacterial community structures. Maximal hydrogen production was five times higher on pentose-based substrates, with specific bacterial community structures producing acetate and butyrate as main metabolites. Low hydrogen amounts accumulated from complex sugars (cellulose, xylan and wheat straw). A relatively high proportion of the reads was affiliated to Ruminococcaceae suggesting an efficient hydrolytic activity. Knowing that the bacterial community structure is very specific to a particular substrate offers new possibilities to design more efficient H2-producing biological systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Structure and mechanism of Zn2+-transporting P-type ATPases

    DEFF Research Database (Denmark)

    Wang, Kaituo; Sitsel, Oleg; Meloni, Gabriele

    2014-01-01

    Zinc is an essential micronutrient for all living organisms. It is required for signalling and proper functioning of a range of proteins involved in, for example, DNA binding and enzymatic catalysis. In prokaryotes and photosynthetic eukaryotes, Zn(2+)-transporting P-type ATPases of class IB (Znt......A) are crucial for cellular redistribution and detoxification of Zn(2+) and related elements. Here we present crystal structures representing the phosphoenzyme ground state (E2P) and a dephosphorylation intermediate (E2·Pi) of ZntA from Shigella sonnei, determined at 3.2 Å and 2.7 Å resolution, respectively....... The structures reveal a similar fold to Cu(+)-ATPases, with an amphipathic helix at the membrane interface. A conserved electronegative funnel connects this region to the intramembranous high-affinity ion-binding site and may promote specific uptake of cellular Zn(2+) ions by the transporter. The E2P structure...

  18. On Toric Poisson Structures of Type (1,1) and their Cohomology

    Science.gov (United States)

    Caine, Arlo; Givens, Berit Nilsen

    2017-04-01

    We classify real Poisson structures on complex toric manifolds of type (1,1) and initiate an investigation of their Poisson cohomology. For smooth toric varieties, such structures are necessarily algebraic and are homogeneous quadratic in each of the distinguished holomorphic coordinate charts determined by the open cones of the associated simplicial fan. As an approximation to the smooth cohomology problem in each C^n chart, we consider the Poisson differential on the complex of polynomial multi-vector fields. For the algebraic problem, we compute H^0 and H^1 under the assumption that the Poisson structure is generically non-degenerate. The paper concludes with numerical investigations of the higher degree cohomology groups of (C^2,π_B) for various B.

  19. Genomic analysis of 495 vancomycin-resistant Enterococcus faecium reveals broad dissemination of a vanA plasmid in more than 19 clones from Copenhagen, Denmark

    DEFF Research Database (Denmark)

    Pinholt, Mette; Gumpert, Heidi; Bayliss, Sion

    2017-01-01

    OBJECTIVES: From 2012 to 2014, there has been a huge increase in vancomycin-resistant (vanA) Enterococcus faecium (VREfm) in Copenhagen, Denmark, with 602 patients infected or colonized with VREfm in 2014 compared with just 22 in 2012. The objective of this study was to describe the genetic......A plasmid was highly covered by reads from isolates containing the type 4 transposon. CONCLUSIONS: This study suggests that it was the dissemination of the type 4 Tn1546-like transposon and plasmid via horizontal transfer to multiple populations of E. faecium, followed by clonal spread of new VREfm clones...

  20. Overview of the Taxonomy of Environmental Types and the Factor Structure of the Salter Environmental Type Assessment.

    Science.gov (United States)

    Salter, Daniel W.; Vandiver, Beverly J.

    2002-01-01

    The Salter Environmental Type Assessment (SETA) was created to be a commensurate measure for the Myers-Briggs Type Indicator and to improve the efficacy of the person-environmental interaction paradigm to student affairs. A confirmatory factor analysis of SETA profiles supported the four dimensions in environmental type theory. The utility of this…

  1. Ensembled support vector machines for human papillomavirus risk type prediction from protein secondary structures.

    Science.gov (United States)

    Kim, Sun; Kim, Jeongmi; Zhang, Byoung-Tak

    2009-02-01

    Infection by the human papillomavirus (HPV) is regarded as the major risk factor in the development of cervical cancer. Detection of high-risk HPV is important for understanding its oncogenic mechanisms and for developing novel clinical tools for its diagnosis, treatment, and prevention. Several methods are available to predict the risk types for HPV protein sequences. Nevertheless, no tools can achieve a universally good performance for all domains, including HPV and nor do they provide confidence levels for their decisions. Here, we describe ensembled support vector machines (SVMs) to classify HPV risk types, which assign given proteins into high-, possibly high-, or low-risk type based on their confidence level. Our approach uses protein secondary structures to obtain the differential contribution of subsequences for the risk type, and SVM classifiers are combined with a simple but efficient string kernel to handle HPV protein sequences. In the experiments, we compare our approach with previous methods in accuracy and F1-score, and present the predictions for unknown HPV types, which provides promising results.

  2. Functional and Structural Analysis of Five Mutations Identified in Methylmalonic Aciduria cbIB Type

    Science.gov (United States)

    Jorge-Finnigan, Ana; Aguado, Cristina; Sánchez-Alcudia, Rocio; Abia, David; Richard, Eva; Merinero, Begoña; Gámez, Alejandra; Banerjee, Ruma; Desviat, Lourdes R.; Ugarte, Magdalena; Pérez, Belen

    2010-01-01

    ATP cob(I)alamin adenosyltransferase (ATR, E.C.2.5.1.17) converts reduced cob(I)alamin to the adenosylcobalamin cofactor. Mutations in the MMAB gene encoding ATR are responsible for the cblB type methylmalonic aciduria. Here we report the functional analysis of five cblB mutations to determine the underlying molecular basis of the dysfunction. The transcriptional profile along with minigenes analysis revealed that c.584G>A, c.349-1G>C and c.290G>A affect the splicing process. Wild-type ATR and the p.I96T (c.287T>C) and p.R191W (c.571C>T) mutant proteins were expressed in a prokaryote and a eukaryotic expression systems. The p.I96T protein was enzymatically active with a KM for ATP and KD for cob(I)alamin similar to wild-type enzyme, but exhibited a 40% reduction in specific activity. Both p.I96T and p.R191W mutant proteins are less stable than the wild-type protein, with increased stability when expressed under permissive folding conditions. Analysis of the oligomeric state of both mutants showed a structural defect for p.I96T and also a significant impact on the amount of recovered mutant protein that was more pronounced for p.R191W that, along with the structural analysis, suggest they might be misfolded. These results could serve as a basis for the implementation of pharmacological therapies aimed at increasing the residual activity of this type of mutations. PMID:20556797

  3. Structure of the outer membrane complex of a type IV secretion system

    Science.gov (United States)

    Chandran, Vidya; Fronzes, Rémi; Duquerroy, Stéphane; Cronin, Nora; Navaza, Jorge; Waksman, Gabriel

    2009-01-01

    Type IV secretion systems are secretion nanomachines spanning the two membranes of Gram-negative bacteria. Three proteins, VirB7, VirB9, and VirB10 assemble into a 1.05 MDa core spanning the inner and outer membranes. This core consists of 14 copies of each of the proteins and forms two layers, the I and O layers, inserting in the inner and outer membrane, respectively. Here we present the crystal structure of a ~0.6 MDa outer membrane complex containing the entire O-layer. This structure is the largest determined for an outer membrane channel and is also unprecedented in being composed of three proteins. Unexpectedly, this structure identifies VirB10 as the outer membrane channel with a unique hydrophobic double helical trans-membrane region. This structure establishes VirB10 as the only known protein crossing both membranes of Gram-negative bacteria. Comparison of the cryo-EM and crystallographic structures point to conformational changes regulating channel opening and closing. PMID:19946264

  4. Crystal Structure of Hcp from Acinetobacter baumannii: A Component of the Type VI Secretion System.

    Directory of Open Access Journals (Sweden)

    Federico M Ruiz

    Full Text Available The type VI secretion system (T6SS is a bacterial macromolecular machine widely distributed in Gram-negative bacteria, which transports effector proteins into eukaryotic host cells or other bacteria. Membrane complexes and a central tubular structure, which resembles the tail of contractile bacteriophages, compose the T6SS. One of the proteins forming this tube is the hemolysin co-regulated protein (Hcp, which acts as virulence factor, as transporter of effectors and as a chaperone. In this study, we present the structure of Hcp from Acinetobacter baumannii, together with functional and oligomerization studies. The structure of this protein exhibits a tight β barrel formed by two β sheets and flanked at one side by a short α-helix. Six Hcp molecules associate to form a donut-shaped hexamer, as observed in both the crystal structure and solution. These results emphasize the importance of this oligomerization state in this family of proteins, despite the low similarity of sequence among them. The structure presented in this study is the first one for a protein forming part of a functional T6SS from A. baumannii. These results will help us to understand the mechanism and function of this secretion system in this opportunistic nosocomial pathogen.

  5. Structural and magnetic Properties of TbZn-substituted calcium barium M-type nano-structured hexa-ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Hasan M. [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Department of Electronics, University of York, York YO10 5DD (United Kingdom); Islam, M.U., E-mail: dr.misbahulislam@bzu.edu.pk [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Xu, Yongbing [Department of Electronics, University of York, York YO10 5DD (United Kingdom); Nanjing–York International Centre of Spintronics and Nano-Engineering, Nanjing University, Nanjing 210093 (China); Asif Iqbal, M. [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); National University of Science and Technology, College of E and ME, Islamabad (Pakistan); Ali, Irshad [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan)

    2014-03-15

    Highlights: • Tb–Zn substituted Ca{sub 0.5}Ba{sub 0.5}Fe{sub 12}O{sub 19} samples exhibit single magnetoplumbite phase. • Lattice parameters a and c have increasing values. • Coercivity can be tuned at lower substitution level • Crystallites size was found in the range 18–25 nm by TEM and by Scherrer formula. • These hexa-ferrites are suitable for microwave devices and magnetic recording media. -- Abstract: Effect of TbZn substitution on the structural and magnetic properties of Ca{sub 0.5}Ba{sub 0.5−x}Tb{sub x}Zn{sub y}Fe{sub 12−y}O{sub 19}, (x = 0.00–0.10; y = 0.00–1.00) ferrites prepared by sol–gel auto combustion is reported. The synthesized samples were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Vibrating Sample magnetometery. The X-ray diffraction analysis confirmed single phase M-type hexa-ferrite structure. The lattice parameters were found to increase as TbZn contents increases, which is attributed to the ionic sizes of the implicated cations. The TbZn seems to be completely soluble in the lattice. The results of scanning electron microscopy and transmission electron microscopy shows that the grain size decreases with increase of TbZn substitution. The coercivity values (1277–2025 Oe) of all samples lies in the range of M-type hexa-ferrite and indicate that an increase of anisotropy was achieved by substitution of TbZn, while the size of nanoparticles was drastically reduced between 18 and 25 nm. The increased anisotropy and fine particle size are useful for many applications, such as improving signal noise ratio of recording devices.

  6. Structural and bioinformatic characterization of an Acinetobacter baumannii type II carrier protein

    Energy Technology Data Exchange (ETDEWEB)

    Allen, C. Leigh; Gulick, Andrew M., E-mail: gulick@hwi.buffalo.edu [University at Buffalo, Buffalo, NY 14203 (United States)

    2014-06-01

    The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented. Microorganisms produce a variety of natural products via secondary metabolic biosynthetic pathways. Two of these types of synthetic systems, the nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), use large modular enzymes containing multiple catalytic domains in a single protein. These multidomain enzymes use an integrated carrier protein domain to transport the growing, covalently bound natural product to the neighboring catalytic domains for each step in the synthesis. Interestingly, some PKS and NRPS clusters contain free-standing domains that interact intermolecularly with other proteins. Being expressed outside the architecture of a multi-domain protein, these so-called type II proteins present challenges to understand the precise role they play. Additional structures of individual and multi-domain components of the NRPS enzymes will therefore provide a better understanding of the features that govern the domain interactions in these interesting enzyme systems. The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented here. Comparison with the closest structural homologs of other carrier proteins identifies the requirements for a conserved glycine residue and additional important sequence and structural requirements within the regions that interact with partner proteins.

  7. Effect of alloy type and casting technique on the fracture strength of implant-cemented structures.

    Science.gov (United States)

    Castillo-de Oyagüe, Raquel; Osorio, Raquel; Lynch, Christopher; Gilmour, Alan; Toledano, Manuel

    2011-07-01

    To evaluate the influence of alloy type and casting procedure on the fracture strength (FS) of metallic frameworks for implant-supported fixed prostheses. Thirty three-unit structures for lower posterior bridges were waxed-up and randomly assigned to two groups (n=15) according to alloy type and casting technique: Group 1 (C): cobalt-chromium cast in a centrifugal machine (TS1, Degussa-Hüls); Group 2 (T): titanium cast in a pressure-differential device (Cyclarc II, Morita). Each structure was cemented onto two prefabricated abutments under a constant seating pressure. After 6 months of water aging, samples were loaded in a static universal testing machine (EFH/5/FR, Microtest) until fracture. Axial compressive loads were applied at the central fossa of the pontics. FS data were recorded and surface topography of the fractured connectors was SEM-analyzed. A Chi-Square test was performed to assess the dependence of pores on the alloy type and casting procedure. ANOVA and Student-Newman-Keuls (SNK) tests were run for FS comparisons (p casting procedure. Cobalt-chromium casts often registered pores inside the connectors, which strongly decreased the fracture resistance. An accurate casting of titanium with a pressure-differential system may result in the most predictable technique under the tested experimental conditions.

  8. Structure of Resilience among Japanese Adult Patients with Type 1 Diabetes: A Qualitative Study.

    Science.gov (United States)

    Nishio, Ikuko; Chujo, Masami

    2017-03-01

    Resilience is the process of overcoming adversities and difficulties. We clarified the structure of resilience and its motivational power among adult Japanese patients with type 1 diabetes. This is likely to help ensure effective nursing support to empower patients with diabetes and help them recuperate and improve their personal lives. Participants were 17 patients with type 1 diabetes, and data were collected using semi-structured interviews. Participants shared their experiences of coping with self-management and diabetes control issues, the meaning of living with diabetes, and their support from family and friends since their diagnosis. Glaser's grounded theory was used to analyze the data and the results were used to create a new model of resilience for type 1 diabetes. Five categories were extracted: "suffering from a guilty conscience," "suffering from an insulin-dependent body," "social disability," "a driving force to advancement," and "possessing a strategy to live with the disease." The five categories formed two stages: preparatory resilience and resilience formation. Once patients recognized the presence of empathetic others, they could obtain better disease comprehension and cooperation. Recognizing this support system served as a "driving force to advancement" and was termed the "resilience battery." Through the resilience battery, patients shifted from preparatory resilience to "resilience formation," or acquiring "a strategy to live with the disease." To forge patient resilience, nurses should encourage disease comprehension and cooperation among patients' significant others. We further propose that high-quality nursing care would involve supporting patients' inner resilience.

  9. Molecular and structural studies of Japanese patients with sialidosis type 1.

    Science.gov (United States)

    Naganawa, Y; Itoh, K; Shimmoto, M; Takiguchi, K; Doi, H; Nishizawa, Y; Kobayashi, T; Kamei, S; Lukong, K E; Pshezhetsky, A V; Sakuraba, H

    2000-01-01

    To gain insight into the pathogenesis of sialidosis type 1, we performed molecular investigations of two unrelated Japanese patients. Both of them are compound heterozygotes for base substitutions of 649G-to-A and 727G-to-A, which result in amino acid alterations V217M and G243R, respectively. Using homology modeling, the structure of human lysosomal neuraminidase was constructed and the structural changes caused by these missense mutations were deduced. The predicted change due to V217M was smaller than that caused by G243R, the latter resulting in a drastic, widespread alteration. The overexpressed gene products containing these mutations had the same molecular weight as that of the wild type, although the amounts of the products were moderately decreased. A biochemical study demonstrated that the expressed neuraminidase containing a V217M mutation was partly transported to lysosomes and showed residual enzyme activity, although a G243R mutant was retained in the endoplasmic reticulum/Golgi area and had completely lost the enzyme activity. Considering the data, we surmise that the V217M substitution may be closely associated with the phenotype of sialidosis type 1 with a late onset and moderate clinical course.

  10. Structure of the Type IVa Major Pilin from the Electrically Conductive Bacterial Nanowires of Geobacter sulfurreducens

    Energy Technology Data Exchange (ETDEWEB)

    Reardon, Patrick N.; Mueller, Karl T.

    2013-10-11

    Several species of bacteria are capable of reducing insoluble metal oxides as well as other extracellular electron acceptors. These bacteria play a critical role in the cycling of minerals in subsurface environments, sediments, and groundwater. In some species of bacteria, such as Geobacter sulfurreducens, the transport of electrons is facilitated by filamentous fibers that are referred to as bacterial nanowires. These nanowires belong to the type IVa family of pilin proteins and are mainly comprised of one subunit protein, PilA. Here, we report the high resolution solution nuclear magnetic resonance (NMR) structure of the PilA protein from G. sulfurreducens determined in detergent micelles. The protein is over 85% α-helical and exhibits similar architecture to the N-terminal regions of other non-conductive type IVa pilins. The detergent micelle interacts with the first 21 amino acids of the protein, indicating that this region likely associates with the bacterial inner membrane prior to fiber formation. A model of the G. sulfurreducens pilus fiber is proposed based on docking of this structure into the fiber model of the type IVa pilin from Neisseria gonorrhoeae. This model provides insight into the organization of aromatic amino acids that are important for electrical conduction.

  11. Annular Protofibrils Are a Structurally and Functionally Distinct Type of Amyloid Oligomer*

    Science.gov (United States)

    Kayed, Rakez; Pensalfini, Anna; Margol, Larry; Sokolov, Yuri; Sarsoza, Floyd; Head, Elizabeth; Hall, James; Glabe, Charles

    2009-01-01

    Amyloid oligomers are believed to play causal roles in several types of amyloid-related neurodegenerative diseases. Several different types of amyloid oligomers have been reported that differ in morphology, size, or toxicity, raising the question of the pathological significance and structural relationships between different amyloid oligomers. Annular protofibrils (APFs) have been described in oligomer preparations of many different amyloidogenic proteins and peptides as ring-shaped or pore-like structures. They are interesting because their pore-like morphology is consistent with numerous reports of membrane-permeabilizing activity of amyloid oligomers. Here we report the preparation of relatively homogeneous preparations of APFs and an antiserum selective for APFs (αAPF) compared with prefibrillar oligomers (PFOs) and fibrils. PFOs appear to be precursors for APF formation, which form in high yield after exposure to a hydrophobic-hydrophilic interface. Surprisingly, preformed APFs do not permeabilize lipid bilayers, unlike the precursor PFOs. APFs display a conformation-dependent, generic epitope that is distinct from that of PFOs and amyloid fibrils. Incubation of PFOs with phospholipids vesicles results in a loss of PFO immunoreactivity with a corresponding increase in αAPF immunoreactivity, suggesting that lipid vesicles catalyze the conversion of PFOs into APFs. The annular anti-protofibril antibody also recognizes heptameric α-hemolysin pores, but not monomers, suggesting that the antibody recognizes an epitope that is specific for a β barrel structural motif. PMID:19098006

  12. Annular protofibrils are a structurally and functionally distinct type of amyloid oligomer.

    Science.gov (United States)

    Kayed, Rakez; Pensalfini, Anna; Margol, Larry; Sokolov, Yuri; Sarsoza, Floyd; Head, Elizabeth; Hall, James; Glabe, Charles

    2009-02-13

    Amyloid oligomers are believed to play causal roles in several types of amyloid-related neurodegenerative diseases. Several different types of amyloid oligomers have been reported that differ in morphology, size, or toxicity, raising the question of the pathological significance and structural relationships between different amyloid oligomers. Annular protofibrils (APFs) have been described in oligomer preparations of many different amyloidogenic proteins and peptides as ring-shaped or pore-like structures. They are interesting because their pore-like morphology is consistent with numerous reports of membrane-permeabilizing activity of amyloid oligomers. Here we report the preparation of relatively homogeneous preparations of APFs and an antiserum selective for APFs (alphaAPF) compared with prefibrillar oligomers (PFOs) and fibrils. PFOs appear to be precursors for APF formation, which form in high yield after exposure to a hydrophobic-hydrophilic interface. Surprisingly, preformed APFs do not permeabilize lipid bilayers, unlike the precursor PFOs. APFs display a conformation-dependent, generic epitope that is distinct from that of PFOs and amyloid fibrils. Incubation of PFOs with phospholipids vesicles results in a loss of PFO immunoreactivity with a corresponding increase in alphaAPF immunoreactivity, suggesting that lipid vesicles catalyze the conversion of PFOs into APFs. The annular anti-protofibril antibody also recognizes heptameric alpha-hemolysin pores, but not monomers, suggesting that the antibody recognizes an epitope that is specific for a beta barrel structural motif.

  13. Prediction algorithm for amino acid types with their secondary structure in proteins (PLATON) using chemical shifts.

    Science.gov (United States)

    Labudde, D; Leitner, D; Krüger, M; Oschkinat, H

    2003-01-01

    The algorithm PLATON is able to assign sets of chemical shifts derived from a single residue to amino acid types with its secondary structure (amino acid species). A subsequent ranking procedure using optionally two different penalty functions yields predictions for possible amino acid species for the given set of chemical shifts. This was demonstrated in the case of the alpha-spectrin SH3 domain and applied to 9 further protein data sets taken from the BioMagRes database. A database consisting of reference chemical shift patterns (reference CSPs) was generated from assigned chemical shifts of proteins with known 3D-structure. This reference CSP database is used in our approach for extracting distributions of amino acid types with their most likely secondary structure elements (namely alpha-helix, beta-sheet, and coil) for single amino acids by comparison with query CSPs. Results obtained for the 10 investigated proteins indicates that the percentage of correct amino acid species in the first three positions in the ranking list, ranges from 71.4% to 93.2% for the more favorable penalty function. Where only the top result of the ranking list for these 10 proteins is considered, 36.5% to 83.1% of the amino acid species are correctly predicted. The main advantage of our approach, over other methods that rely on average chemical shift values is the ability to increase database content by incorporating newly derived CSPs, and therefore to improve PLATON's performance over time.

  14. Connexin Type and Fluorescent Protein Fusion Tag Determine Structural Stability of Gap Junction Plaques*

    Science.gov (United States)

    Stout, Randy F.; Snapp, Erik Lee; Spray, David C.

    2015-01-01

    Gap junctions (GJs) are made up of plaques of laterally clustered intercellular channels and the membranes in which the channels are embedded. Arrangement of channels within a plaque determines subcellular distribution of connexin binding partners and sites of intercellular signaling. Here, we report the discovery that some connexin types form plaque structures with strikingly different degrees of fluidity in the arrangement of the GJ channel subcomponents of the GJ plaque. We uncovered this property of GJs by applying fluorescence recovery after photobleaching to GJs formed from connexins fused with fluorescent protein tags. We found that connexin 26 (Cx26) and Cx30 GJs readily diffuse within the plaque structures, whereas Cx43 GJs remain persistently immobile for more than 2 min after bleaching. The cytoplasmic C terminus of Cx43 was required for stability of Cx43 plaque arrangement. We provide evidence that these qualitative differences in GJ arrangement stability reflect endogenous characteristics, with the caveat that the sizes of the GJs examined were necessarily large for these measurements. We also uncovered an unrecognized effect of non-monomerized fluorescent protein on the dynamically arranged GJs and the organization of plaques composed of multiple connexin types. Together, these findings redefine our understanding of the GJ plaque structure and should be considered in future studies using fluorescent protein tags to probe dynamics of highly ordered protein complexes. PMID:26265468

  15. On the Structure of the AGN Torus through the Fraction of Optically Selected Type 1 AGNs

    Science.gov (United States)

    Khim, Honggeun; Yi, Sukyoung K.

    2017-09-01

    The ratio in number between unobscured (type 1) and obscured (type 2) active galactic nuclei (AGNs) is often used to explore the structure of the torus in the unified scheme for AGNs. Oh et al. (2015) investigated the type 1 AGN fraction on two-dimensional space in terms of black hole mass ({M}{BH}) and bolometric luminosity ({L}{bol}) and found that the fraction changes depending on both {M}{BH} and {L}{bol}, forming a ridge-shaped distribution. In this study, based on the up-to-date type 1 AGN catalog of Oh et al. (2015), we examine how the trend of the type 1 AGN fraction in the {M}{BH}-{L}{bol} plane is affected by the different methods used to derive {M}{BH} and {L}{bol}, and suggest an analytic model to explain the observations. We use galaxies from the Sloan Digital Sky Survey Data Release 7 in the redshift range 0.01≤slant z≤slant 0.2. In estimating {L}{bol}, we employ two different methods using [{{O}} {{III}}] and/or [{{O}} {{I}}] emission lines, and find that the {L}{bol} values obtained from the two methods agree well. We consider the {M}{BH}{--}{σ }* relation, the {{M}}{{BH}}-L bulge relation, and the single-epoch Hα-based {M}{BH} estimate in calculating {M}{BH}. We find that the trends of the type 1 AGN fraction with respect to {M}{BH} and {L}{bol} are similar for the different methods of deriving {L}{bol} but different when using different methods to derive {M}{BH}. We present a model based on the clumpy-torus scheme that reproduces the ridge-shaped distribution of the fraction parallel to the iso-Eddington ratio lines.

  16. Function and Evolutionary Origin of Unicellular Camera-Type Eye Structure

    KAUST Repository

    Hayakawa, Shiho

    2015-03-03

    The ocelloid is an extraordinary eyespot organelle found only in the dinoflagellate family Warnowiaceae. It contains retina- and lens-like structures called the retinal body and the hyalosome. The ocelloid has been an evolutionary enigma because of its remarkable resemblance to the multicellular camera-type eye. To determine if the ocelloid is functionally photoreceptive, we investigated the warnowiid dinoflagellate Erythropsidinium. Here, we show that the morphology of the retinal body changed depending on different illumination conditions and the hyalosome manifests the refractile nature. Identifying a rhodopsin gene fragment in Erythropsidinium ESTs that is expressed in the retinal body by in situ hybridization, we also show that ocelloids are actually light sensitive photoreceptors. The rhodopsin gene identified is most closely related to bacterial rhodopsins. Taken together, we suggest that the ocelloid is an intracellular camera-type eye, which might be originated from endosymbiotic origin. © 2015 Hayakawa et al.

  17. Electronic Structure and Doping of P-Type Transparent Conducting Oxides: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wei, S.-H.; Nie, X.; Zhang, S. B.

    2002-05-01

    Transparent conducting oxides (TCOs) are a group of materials that are widely used in solar cells and other optoelectronic devices. Recently, Cu-containing p-type TCOs such as MII Cu2 O2 (MIII=Mg, Ca, Sr, Ba) and CuMIII O2 (MIII=Al, Ga, In) have been proposed. Using first-principles band structure methods, we have systematically studied the electronic and optical properties of these p-type transparent oxides. For MII Cu2 O2 , we predict that adding a small amount of Ca into Sr Cu2 O2 can increase the transparency and conductivity. For CuMIII O2 , we explained the doping and band gap anomalies in this system and proposed a new approach to search for bipolar dopable wide-gap materials.

  18. The effectiveness of structured personal care of type 2 diabetes on recurrent outcomes

    DEFF Research Database (Denmark)

    Lundström, Hanna Maria; Siersma, Volkert Dirk; Nielsen, Anni Brit Sternhagen

    2014-01-01

    Abstract AIMS/HYPOTHESIS: The estimation of effect size in clinical trials commonly disregards recurrent outcomes. We investigated the effectiveness of a complex intervention on recurrent outcomes in patients with type 2 diabetes. METHODS: In the Diabetes Care in General Practice (DCGP) randomised...... controlled trial, 1,381 patients newly diagnosed with type 2 diabetes were randomised to 6 years of structured personal care or routine care (ClinicalTrials.gov NCT01074762). The trial had 19 years of registry-based follow-up and was analysed with Cox regression models. Repeated occurrences in the same...... patient of outcomes (any diabetes-related endpoint, myocardial infarction [MI], stroke, peripheral vascular disease and microvascular disease) were accounted for with the Wei, Lin and Weissfeld method. RESULTS: As previously shown, the intervention reduced the rates of first occurrence of both MI and any...

  19. The structure of parental involvement and relations to disease management for youth with type 1 diabetes.

    Science.gov (United States)

    Palmer, Debra L; Osborn, Peter; King, Pamela S; Berg, Cynthia A; Butler, Jorie; Butner, Jonathan; Horton, Dwayne; Wiebe, Deborah J

    2011-06-01

    To test structural models of parental involvement in type 1 diabetes and to examine associations of parental involvement with adherence and metabolic control. Two hundred and fifty-two young adolescents (10-14 years) completed reports of adherence and parents' involvement: acceptance, independence encouragement, communication, general and diabetes-specific monitoring, frequency of help, and intrusive support. HbA(1c) values came from medical records. A model of relationship quality, behavioral involvement, and monitoring as three separate yet interrelated factors best fit the data. Higher reports of mothers' and fathers' monitoring and fathers' relationship quality uniquely related to better adherence, whereas higher reports of fathers' behavioral involvement uniquely related to poorer adherence. Higher reports of paternal monitoring were related to lower HbA(1c). Adolescent perceptions of components of parental involvement are interrelated, yet separate constructs for both mothers and fathers. Parental monitoring was an important predictor of management of type 1 diabetes during adolescence.

  20. Structural linkage between ligand discrimination and receptor activation by type I interferons.

    Science.gov (United States)

    Thomas, Christoph; Moraga, Ignacio; Levin, Doron; Krutzik, Peter O; Podoplelova, Yulia; Trejo, Angelica; Lee, Choongho; Yarden, Ganit; Vleck, Susan E; Glenn, Jeffrey S; Nolan, Garry P; Piehler, Jacob; Schreiber, Gideon; Garcia, K Christopher

    2011-08-19

    Type I Interferons (IFNs) are important cytokines for innate immunity against viruses and cancer. Sixteen human type I IFN variants signal through the same cell-surface receptors, IFNAR1 and IFNAR2, yet they can evoke markedly different physiological effects. The crystal structures of two human type I IFN ternary signaling complexes containing IFNα2 and IFNω reveal recognition modes and heterotrimeric architectures that are unique among the cytokine receptor superfamily but conserved between different type I IFNs. Receptor-ligand cross-reactivity is enabled by conserved receptor-ligand "anchor points" interspersed among ligand-specific interactions that "tune" the relative IFN-binding affinities, in an apparent extracellular "ligand proofreading" mechanism that modulates biological activity. Functional differences between IFNs are linked to their respective receptor recognition chemistries, in concert with a ligand-induced conformational change in IFNAR1, that collectively control signal initiation and complex stability, ultimately regulating differential STAT phosphorylation profiles, receptor internalization rates, and downstream gene expression patterns. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Dance Class Structure Affects Youth Physical Activity and Sedentary Behavior: A Study of Seven Dance Types.

    Science.gov (United States)

    Lopez Castillo, Maria A; Carlson, Jordan A; Cain, Kelli L; Bonilla, Edith A; Chuang, Emmeline; Elder, John P; Sallis, James F

    2015-01-01

    The study aims were to determine: (a) how class structure varies by dance type, (b) how moderate-to-vigorous physical activity (MVPA) and sedentary behavior vary by dance class segments, and (c) how class structure relates to total MVPA in dance classes. Participants were 291 boys and girls ages 5 to 18 years old enrolled in 58 dance classes at 21 dance studios in Southern California. MVPA and sedentary behavior were assessed with accelerometry, with data aggregated to 15-s epochs. Percent and minutes of MVPA and sedentary behavior during dance class segments and percent of class time and minutes spent in each segment were calculated using Freedson age-specific cut points. Differences in MVPA (Freedson 3 Metabolic Equivalents of Tasks age-specific cut points) and sedentary behavior ( dance types, with the exception that in ballet, more time was spent in technique as compared with private jazz/hip-hop classes and Latin-flamenco and less time was spent in routine/practice as compared with Latin-salsa/ballet folklorico. Segment type accounted for 17% of the variance in the proportion of the segment spent in MVPA. The proportion of the segment in MVPA was higher for routine/practice (44.2%) than for technique (34.7%). The proportion of the segment in sedentary behavior was lowest for routine/practice (22.8%). The structure of dance lessons can impact youths' physical activity. Working with instructors to increase time in routine/practice during dance classes could contribute to physical activity promotion in youth.

  2. Effect of boundary conditions on magnetocapacitance effect in a ring-type magnetoelectric structure

    Science.gov (United States)

    Zhang, Juanjuan

    2017-12-01

    By considering the nonlinear magneto-elastic coupling relationships of magnetostrictive materials, an analytical model is proposed. The resonance frequencies can be accurately predicted by this theoretical model, and they are in good agreement with experimental data. Subsequently, the magnetocapacitance effect in a ring-type magnetoelectric (ME) structure with different boundary conditions is investigated, and it is found that various mechanical boundaries, the frequency, the magnetic field, the geometric size, and the interface bonding significantly affect the capacitance of the ME structure. Further, additional resonance frequencies can be predicted by considering appropriate imperfect interface bonding. Finally, the influence of an external force on the capacitance is studied. The result shows that an external force on the boundary changes the capacitance, but has only a weak influence on the resonance frequency.

  3. How can structured self-management patient education improve outcomes in people with type 2 diabetes?

    DEFF Research Database (Denmark)

    Jarvis, J.; Skinner, T. C.; Carey, M. E.

    2010-01-01

    decisions and choices about treatments and lifestyle on a day-to-day basis. Equipping a person with these self-management skills is in itself challenging and it is now widely accepted that structured education is an integral part of the management of T2DM. This paper explores whether structured self-management......Type 2 diabetes (T2DM) is a long-term chronic condition that is complex to manage, with the majority of management being done by the person with diabetes outside of the clinical setting. Because of its complexities, effective self-management requires skills, confidence and the ability to make...... education can improve outcomes in people with diabetes. The authors explore what self-management education is, why it is needed and then go on to examine the recent evidence from clinical trials from 2006 onwards....

  4. Electronic structure of ionic PbFCl-type compounds under pressure

    CERN Document Server

    Kanchana, V; Rajagopalan, M

    2003-01-01

    The electronic structures of alkaline-earth fluoro-halides - SrFBr, SrFI, and CaFBr, which crystallize in the PbFCl-type structure - have been studied using the tight-binding linear muffin-tin orbital method within the local density approximation. The total energies were calculated using the atomic sphere approximation and were used to determine the ground state properties of these systems. The calculated ground state properties agree fairly well with the experimental results. These systems were found to be direct band gap insulators. The pressure dependence of the band gap was also studied. The band gap closes at high pressures leading to band overlap. A possible reason for the metallization in these compounds is discussed.

  5. Simulating the service life performance of an inspected group of jacket-type structures

    DEFF Research Database (Denmark)

    Schneider, Ronald; Thöns, Sebastian; Rogge, Andreas

    2017-01-01

    failure probability conditional on simulated inspection and repair histories, and evaluates the associated costs and risk. The expected total service life costs and risk for a strategy are finally determined using Monte Carlo simulation. The optimal strategy minimizes the expected total service life costs...... and risk. We intend to adopt this approach to optimize inspection, monitoring and repair activities for offshore wind park support structures. As a first step, we simulate – in analogy to an offshore wind park – the service life performance of an inspected group of jacket-type frames. The performance...... is quantified in terms of the group’s system failure probability conditional on simulated inspection and repair histories. The underlying system model accounts for the structural redundancy of the frames and the interdependence among their failure events due to similar loading conditions. The model also...

  6. Heterotic and type II orientifold compactifications on SU(3) structure manifolds

    Energy Technology Data Exchange (ETDEWEB)

    Benmachiche, I.

    2006-07-15

    We study the four-dimensional N=1 effective theories of generic SU(3) structure compactifications in the presence of background fluxes. For heterotic and type IIA/B orientifold theories, the N=1 characteristic data are determined by a Kaluza-Klein reduction of the fermionic actions. The Kaehler potentials, superpotentials and the D-terms are entirely encoded by geometrical data of the internal manifold. The background flux and the intrinsic torsion of the SU(3) structure manifold, gives rise to contributions to the four-dimensional F-terms. The corresponding superpotentials generalize the Gukov-Vafa-Witten superpotential. For the heterotic compactification, the four-dimensional fermionic supersymmetry variations, as well as the conditions on supersymmetric vacua, are determined. The Yukawa couplings of the theory turn out to be similar to their Calabi-Yau counterparts. (Orig.)

  7. Influence of Gd addition on the magnetism and structure of Finemet-type nanocrystalline alloys

    Energy Technology Data Exchange (ETDEWEB)

    Crisan, O. E-mail: ocrisan@alpha2.infim.roocrisan@yahoo.com; Le Breton, J.M.; Crisan, A.D.; Machizaud, F

    2004-05-01

    The effect of rare earth addition in the structure and magnetism of melt spun nanocrystalline Finemet-type alloys devitrified from amorphous precursor ribbons is discussed. Starting with the initial composition Fe{sub 73.5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9} an amount of 5 at% Gd is introduced into the primary alloy. The purpose is to enable after appropriate recrystallization the occurrence of hard and soft magnetic, suitably dispersed, exchange-coupled nanograins and to determine the transformation sequences of the crystallization process and the obtained crystallization products.

  8. Impact of model structure and parameterization on Penman-Monteith type evaporation models

    KAUST Repository

    Ershadi, A.

    2015-04-12

    The impact of model structure and parameterization on the estimation of evaporation is investigated across a range of Penman-Monteith type models. To examine the role of model structure on flux retrievals, three different retrieval schemes are compared. The schemes include a traditional single-source Penman-Monteith model (Monteith, 1965), a two-layer model based on Shuttleworth and Wallace (1985) and a three-source model based on Mu et al. (2011). To assess the impact of parameterization choice on model performance, a number of commonly used formulations for aerodynamic and surface resistances were substituted into the different formulations. Model response to these changes was evaluated against data from twenty globally distributed FLUXNET towers, representing a cross-section of biomes that include grassland, cropland, shrubland, evergreen needleleaf forest and deciduous broadleaf forest. Scenarios based on 14 different combinations of model structure and parameterization were ranked based on their mean value of Nash-Sutcliffe Efficiency. Results illustrated considerable variability in model performance both within and between biome types. Indeed, no single model consistently outperformed any other when considered across all biomes. For instance, in grassland and shrubland sites, the single-source Penman-Monteith model performed the best. In croplands it was the three-source Mu model, while for evergreen needleleaf and deciduous broadleaf forests, the Shuttleworth-Wallace model rated highest. Interestingly, these top ranked scenarios all shared the simple lookup-table based surface resistance parameterization of Mu et al. (2011), while a more complex Jarvis multiplicative method for surface resistance produced lower ranked simulations. The highly ranked scenarios mostly employed a version of the Thom (1975) formulation for aerodynamic resistance that incorporated dynamic values of roughness parameters. This was true for all cases except over deciduous broadleaf

  9. Particular qualities of intranasal structures conditions in children with type 1 diabetes

    Directory of Open Access Journals (Sweden)

    Layko А.

    2016-03-01

    Full Text Available Objective: To examine particular qualities of the intranasal structures state in children and adolescent patients with type 1 diabetes (T1D. Patients and methods. During the period of 2013–2015 161 patients with type 1 were examined having been treated at the endocrinology department of the National Children's Specialized Hospital OKHMATDET and Children's Hospital №6 (Kyiv. The study group included 138 (85.7% patients with type-1 with the changes of intranasal structures, the control group — 23 (14.3% patients with type-1 with no pathology of upper respiratory tract. Among children of the main group — 92 (66.67% boys and 46 (33.33% girls aged 6–17. All children received clinical and laboratory examination in accordance with the protocols, as well as endoscopy of the nasal cavity, nasopharynx, paranasal sinus computed tomography (if necessary. Results. The most pronounced changes of intranasal structures in children with T1D in the study group were identified in the form of the curvature of the nasal septum (IEF. Endoscopic examination of the nasal cavity and nasopharynx in children of the main group diagnosed the hypertrophy of the inferior turbinate in 54% of patients, acute rhinosinusitis — 12%, chronic adenoids, adenoid vegetations in 10%, polyps — 2%. Microcirculatory disorders according to the nail bed capillaroscopy in patients of the main group were observed 3 times more often than the control group. As a result of bulbar microscopy for children with T1D and IEF vascular changes in a single non-niformity of the caliber of vessels were identified in — 75%, unit sakkulyation venules — 50% maendricus tortuosity of the capillaries — 75%, as well as single-venular anastomoses arteriolo — 37.5%. Intra- and extravascular changes in this group of patients have not been identified. Conclusions. The results of studies in children with T1D indicate the need for timely early diagnosis of the state of intranasal structures and

  10. A note on the prolongation structure of the cubically nonlinear integrable Camassa-Holm type equation

    Energy Technology Data Exchange (ETDEWEB)

    Stalin, S. [Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India); Senthilvelan, M., E-mail: velan@cnld.bdu.ac.in [Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India)

    2011-10-17

    In this Letter, we formulate an exterior differential system for the newly discovered cubically nonlinear integrable Camassa-Holm type equation. From the exterior differential system we establish the integrability of this equation. We then study Cartan prolongation structure of this equation. We also discuss the method of identifying conservation laws and Baecklund transformation for this equation from the identified exterior differential system. -- Highlights: → An exterior differential system for a cubic nonlinear integrable equation is given. → The conservation laws from the exterior differential system is derived. → The Baecklund transformation from the Cartan-Ehresmann connection is obtained.

  11. Wildfires alter rodent community structure across four vegetation types in southern California, USA

    Science.gov (United States)

    Brehme, Cheryl S.; Clark, Denise R.; Rochester, Carlton J.; Fisher, Robert N.

    2011-01-01

    We surveyed burned and unburned plots across four habitat reserves in San Diego County, California, USA, in 2005 and 2006, to assess the effects of the 2003 wildfires on the community structure and relative abundance of rodent species. The reserves each contained multiple vegetation types (coastal sage scrub, chaparral, woodland, and grassland) and spanned from 250 m to 1078 m in elevation. Multivariate analyses revealed a more simplified rodent community structure in all burned habitats in comparison to unburned habitats. Reduction in shrub and tree cover was highly predictive of changes in post-fire rodent community structure in the burned coastal sage scrub and chaparral habitats. Reduction in cover was not predictive for the less substantially burned woodlands and grasslands, for which we hypothesized that interspecific competition played a greater role in post-fire community structure. Across vegetation types, generalists and open habitat specialists typically increased in relative abundance, whereas closed habitat specialists decreased. We documented significant increases in relative abundance of the deer mouse (Peromyscus maniculatus Wagner) and Dulzura kangaroo rat (Dipodomys simulans Merriam). In contrast, we found significant decreases in relative abundance for the California mouse (Peromyscus californicus Gambel), San Diego pocket mouse (Chaetodipus fallax Merriam), desert woodrat (Neotoma lepida Thomas), and brush mouse (Peromyscus boylii Baird). Currently, our research program involves assessment of whether habitat conservation plans (HCPs) in southern California provide long-term protection to HCP covered species, as well as preserve ecosystem function. The scenario of increased wildfires needs to be incorporated into this assessment. We discuss our results in relation to management and conservation planning under a future scenario of larger and more frequent wildfires in southern California.

  12. Nanoscale heterogeneity as remnant hexagonal-type local structures in shocked Cu-Pb and Zr

    Science.gov (United States)

    Tayal, Akhil; Conradson, Steven D.; Batuk, Olga N.; Fensin, Saryu; Cerreta, Ellen; Gray, George T.; Saxena, Avadh

    2017-09-01

    Extended X-ray absorption fine structure spectroscopy was used to determine the local structure in: (1) Zr that had undergone quasistatic elongation; (2) Zr that had undergone plastic deformation by shock at pressures above and below the ω-phase transformation; and (3) shocked Cu that contained a few percent of insoluble Pb. Below the transition pressure, Zr samples showed only general disorder as increases in the widths of the Zr-Zr pair distributions. Above this pressure, Zr that was a mixture of the original hcp and the high pressure ω-phase when measured by diffraction showed two sets of peaks in its distribution corresponding to these two phases. Some of the ones from the ω-phase were at distances substantially different from those calculated from the diffraction pattern, although they are still consistent with small domains exhibiting stacking faults associated with hexagonal-type structural components exhibiting variability in the [0001] basal plane spacing. A similar result, new pairs at just over 3 and 4 Å consistent with hexagonal-type stacking faults in addition to the original fcc structure, is found in shocked Cu despite the absence of a second diffraction pattern and peak pressures being far below those expected to induce an fcc to hcp transition. This result, therefore, demonstrates that the correlation between high strain rates and reduced stacking fault energy continues down to the length scale of atom pairs. These findings are significant as: (1) a microscopic description of the behavior of systems far from equilibrium; (2) a demonstration of the importance of strain rate at short length scales; and (3) a bridge between the abruptness of macroscopic pressure-induced phase transitions and the continuity of martensitic ones over their fluctuation region in terms of the inverse relationship between the length scale of the martensitic texture, manifested here as ordered lattice distortions and the lower pressure at which such texture first appears

  13. Structure of a microsporidian methionine aminopeptidase type 2 complexed with fumagillin and TNP-470

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado, J.; Nemkal, A; Sauder, J; Russell, M; Akiyoshi, D; Shi, W; Almo, S; Weiss, L

    2009-01-01

    Microsporidia are protists that have been reported to cause infections in both vertebrates and invertebrates. They have emerged as human pathogens particularly in patients that are immunosuppressed and cases of gastrointestinal infection, encephalitis, keratitis, sinusitis, myositis and disseminated infection are well described in the literature. While benzimidazoles are active against many species of microsporidia, these drugs do not have significant activity against Enterocytozoon bieneusi. Fumagillin and its analogues have been demonstrated to have activity in vitro and in animal models of microsporidiosis and human infections due to E. bieneusi. Fumagillin and its analogues inhibit methionine aminopeptidase type 2. Encephalitozoon cuniculi MetAP2 (EcMetAP2) was cloned and expressed as an active enzyme using a baculovirus system. The crystal structure of EcMetAP2 was determined with and without the bound inhibitors fumagillin and TNP-470. This structure classifies EcMetAP2 as a member of the MetAP2c family. The EcMetAP2 structure was used to generate a homology model of the E. bieneusi MetAP2. Comparison of microsporidian MetAP2 structures with human MetAP2 provides insights into the design of inhibitors that might exhibit specificity for microsporidian MetAP2.

  14. Structure of a translocation signal domain mediating conjugative transfer by type IV secretion systems.

    Science.gov (United States)

    Redzej, Adam; Ilangovan, Aravindan; Lang, Silvia; Gruber, Christian J; Topf, Maya; Zangger, Klaus; Zechner, Ellen L; Waksman, Gabriel

    2013-07-01

    Relaxases are proteins responsible for the transfer of plasmid and chromosomal DNA from one bacterium to another during conjugation. They covalently react with a specific phosphodiester bond within DNA origin of transfer sequences, forming a nucleo-protein complex which is subsequently recruited for transport by a plasmid-encoded type IV secretion system. In previous work we identified the targeting translocation signals presented by the conjugative relaxase TraI of plasmid R1. Here we report the structure of TraI translocation signal TSA. In contrast to known translocation signals we show that TSA is an independent folding unit and thus forms a bona fide structural domain. This domain can be further divided into three subdomains with striking structural homology with helicase subdomains of the SF1B family. We also show that TSA is part of a larger vestigial helicase domain which has lost its helicase activity but not its single-stranded DNA binding capability. Finally, we further delineate the binding site responsible for translocation activity of TSA by targeting single residues for mutations. Overall, this study provides the first evidence that translocation signals can be part of larger structural scaffolds, overlapping with translocation-independent activities. © 2013 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

  15. Structural and functional cardiac changes in myotonic dystrophy type 1: a cardiovascular magnetic resonance study

    Directory of Open Access Journals (Sweden)

    Hermans Mieke CE

    2012-07-01

    Full Text Available Abstract Background Myotonic dystrophy type 1 (MD1 is a neuromuscular disorder with potential involvement of the heart and increased risk of sudden death. Considering the importance of cardiomyopathy as a predictor of prognosis, we aimed to systematically evaluate and describe structural and functional cardiac alterations in patients with MD1. Methods Eighty MD1 patients underwent physical examination, electrocardiography (ECG, echocardiography and cardiovascular magnetic resonance (CMR. Blood samples were taken for determination of NT-proBNP plasma levels and CTG repeat length. Results Functional and structural abnormalities were detected in 35 patients (44%. Left ventricular systolic dysfunction was found in 20 cases, left ventricular dilatation in 7 patients, and left ventricular hypertrophy in 6 patients. Myocardial fibrosis was seen in 10 patients (12.5%. In general, patients had low left ventricular mass indexes. Right ventricular involvement was uncommon and only seen together with left ventricular abnormalities. Functional or structural cardiac involvement was associated with age (p = 0.04, male gender (p Conclusions CMR can be useful to detect early structural and functional myocardial abnormalities in patients with MD1. Myocardial involvement is strongly associated with conduction abnormalities, but a normal ECG does not exclude myocardial alterations. These findings lend support to the hypothesis that MD1 patients have a complex cardiac phenotype, including both myocardial and conduction system alteration.

  16. UNIFIED CONTROL STRUCTURE OF MULTI-TYPE INTERIOR PERMANENT MAGNET MOTOR

    Directory of Open Access Journals (Sweden)

    M. NORHISAM

    2015-03-01

    Full Text Available This paper presents the control strategy structure to extract the speed torque characteristic for the newly designed three phase Multi Type Interior Permanent Magnet Motor. The proposed structure with the driving circuits exhibit the performance of torque characteristics of the stepper motor and brushless motor with independent coil winding per phase especially used as an in-wheel motor in agricultural applications. Brushless Direct Current motors exhibit characteristics of generating high torque at high speed while the Permanent Magnet Stepper motors has characteristic of generating high torque at low speed. The typical characteristics of the above two are integrated in the proposed structure with a complex control structure that handle the switching complexity and speed control in real time. Thus, a specially designed driving system is essential to drive and control this special motor. The evaluation of the motor mechanical characteristics when applying load torque is also presented. The result determines the practical torque range applicable for each motor configuration and as combined machine.

  17. Robotically Assembled Aerospace Structures: Digital Material Assembly using a Gantry-Type Assembler

    Science.gov (United States)

    Trinh, Greenfield; Copplestone, Grace; O'Connor, Molly; Hu, Steven; Nowak, Sebastian; Cheung, Kenneth; Jenett, Benjamin; Cellucci, Daniel

    2017-01-01

    This paper evaluates the development of automated assembly techniques for discrete lattice structures using a multi-axis gantry type CNC machine. These lattices are made of discrete components called "digital materials." We present the development of a specialized end effector that works in conjunction with the CNC machine to assemble these lattices. With this configuration we are able to place voxels at a rate of 1.5 per minute. The scalability of digital material structures due to the incremental modular assembly is one of its key traits and an important metric of interest. We investigate the build times of a 5x5 beam structure on the scale of 1 meter (325 parts), 10 meters (3,250 parts), and 30 meters (9,750 parts). Utilizing the current configuration with a single end effector, performing serial assembly with a globally fixed feed station at the edge of the build volume, the build time increases according to a scaling law of n4, where n is the build scale. Build times can be reduced significantly by integrating feed systems into the gantry itself, resulting in a scaling law of n3. A completely serial assembly process will encounter time limitations as build scale increases. Automated assembly for digital materials can assemble high performance structures from discrete parts, and techniques such as built in feed systems, parallelization, and optimization of the fastening process will yield much higher throughput.

  18. ZnTaO2N: Stabilized High-Temperature LiNbO3-type Structure.

    Science.gov (United States)

    Kuno, Yoshinori; Tassel, Cédric; Fujita, Koji; Batuk, Dmitry; Abakumov, Artem M; Shitara, Kazuki; Kuwabara, Akihide; Moriwake, Hiroki; Watabe, Daichi; Ritter, Clemens; Brown, Craig M; Yamamoto, Takafumi; Takeiri, Fumitaka; Abe, Ryu; Kobayashi, Yoji; Tanaka, Katsuhisa; Kageyama, Hiroshi

    2016-12-14

    By using a high-pressure reaction, we prepared a new oxynitride ZnTaO2N that crystallizes in a centrosymmetric (R3̅c) high-temperature LiNbO3-type structure (HTLN-type). The stabilization of the HTLN-type structure down to low temperatures (at least 20 K) makes it possible to investigate not only the stability of this phase, but also the phase transition to a noncentrosymmetric (R3c) LiNbO3-type structure (LN-type) which is yet to be clarified. Synchrotron and neutron diffraction studies in combination with transmission electron microscopy show that Zn is located at a disordered 12c site instead of 6a, implying an order-disorder mechanism of the phase transition. It is found that the closed d-shell of Zn2+, as well as the high-valent Ta5+ ion, is responsible for the stabilization of the HTLN-type structure, affording a novel quasitriangular ZnO2N coordination. Interestingly, only 3% Zn substitution for MnTaO2N induces a phase transition from LN- to HTLN-type structure, implying the proximity in energy between the two structural types, which is supported by the first-principles calculations.

  19. Electronic structure and chemical bonding in LaIrSi-type intermetallics

    Energy Technology Data Exchange (ETDEWEB)

    Matar, Samir F. [Bordeaux Univ., Pessac (France). CNRS; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Nakhl, Michel [Univ. Libanaise, Fanar (Lebanon). Ecole Doctorale Sciences et Technologies

    2017-05-01

    The cubic LaIrSi type has 23 representatives in aluminides, gallides, silicides, germanides, phosphides, and arsenides, all with a valence electron count of 16 or 17. The striking structural motif is a three-dimensional network of the transition metal (T) and p element (X) atoms with TX{sub 3/3} respectively XT{sub 3/3} coordination. Alkaline earth or rare earth atoms fill cavities within the polyanionic [TX]{sup δ-} networks. The present work presents a detailed theoretical study of chemical bonding in LaIrSi-type representatives, exemplarily for CaPtSi, BaIrP, BaAuGa, LaIrSi, CeRhSi, and CeIrSi. DFT-GGA-based electronic structure calculations show weakly metallic compounds with itinerant small magnitude DOSs at E{sub F} except for CeRhSi whose large Ce DOS at E{sub F} leads to a finite magnetization on Ce (0.73 μ{sub B}) and induced small moments of opposite sign on Rh and Si in a ferromagnetic ground state. The chemical bonding analyses show dominant bonding within the [TX]{sup δ-} polyanionic networks. Charge transfer magnitudes were found in accordance with the course of the electronegativites of the chemical constituents.

  20. The Comparative Observational Study of Timescale of Feedback by Bar Structure in Late-type Galaxies

    Science.gov (United States)

    Woong-bae Woong-bae Zee, Galaxy; Yoon, Suk-jin

    2018-01-01

    We investigate star formation activities of ~400 barred and ~1400 unbarred faced-on late-type galaxies from the SDSS DR13. We find that gas-poor and barred galaxies are considerably show enhanced high central star formation activities, while there is no difference among gas-rich barred and unbarred galaxies regardless of their HI gas content. This seems counter-intuitive given that gas contents simply represent the total star formation rate of galaxies and suggests that there is a time delation between the central gas migration/consumption through bar structures and the enhancement of star formation activity at the centre. We analysed the distribution of the stellar population of specific galaxies with MaNGA (Mapping Nearby Galaxies at APO) IFU survey among the total samples. The gas-poor and barred galaxies show the flatter gradient in metallicity and age with respect to the stellar mass than other types of galaxies, in that their centre is more metal-rich and younger. There is an age difference, about 5-6 Gyrs, between centrally star-forming gas-poor barred galaxies and gas-rich galaxies and this value is a plausible candidate of the longevity of bar feedback. The results indicate that the gas migration/mixing driven by bar structure plays a significant role in the evolution of galaxies in a specific of timescale.

  1. Structural features of Cas2 from Thermococcus onnurineus in CRISPR-cas system type IV.

    Science.gov (United States)

    Jung, Tae-Yang; Park, Kwang-Hyun; An, Yan; Schulga, Alexy; Deyev, Sergey; Jung, Jong-Hyun; Woo, Eui-Jeon

    2016-10-01

    CRISPR-Cas is RNA-based prokaryotic immune systems that defend against exogenous genetic elements such as plasmids and viruses. Cas1 and Cas2 are highly conserved components that play an essential part in the adaptation stage of all CRISPR-Cas systems. Characterization of CRISPR-Cas genes in Thermococcus onnurineus reveals the association of the Cas2 gene with the putative type IV system that lacks Cas1 or its homologous genes. Here, we present a crystal structure of T. onnurineus Cas2 (Ton_Cas2) that exhibits a deep and wide cleft at an interface lined with positive residues (Arg16, Lys18, Lys19, Arg22, and Arg23). The obvious DNA recognizing loops in Cas2 from E. coli (Eco_Cas2) are absent in Ton_Cas2 and have significantly different shapes and electrostatic potential distributions around the putative nucleotide binding region. Furthermore, Ton_Cas2 lacks the hairpin motif at the C-terminus that is responsible for Cas1 binding in Eco_Cas2. These structural features could be a unique signature and indicate an altered functional mechanism in the adaptation stage of Cas2 in type IV CRISPR-Cas systems. © 2016 The Protein Society.

  2. Synthesis and ferroelectric properties of rare earth compounds with tungsten bronze-type structure

    Energy Technology Data Exchange (ETDEWEB)

    Bouziane, M., E-mail: bouzianemeryem@yahoo.fr [Laboratoire de Chimie du Solide Appliquee, Faculte des Sciences, Avenue Ibn Batouta, BP 1014, Rabat (Morocco); Taibi, M. [Laboratoire de Physico-Chimie des Materiaux, LAF 502, Ecole Normale Superieure, BP 5118, Rabat (Morocco); Boukhari, A. [Laboratoire de Chimie du Solide Appliquee, Faculte des Sciences, Avenue Ibn Batouta, BP 1014, Rabat (Morocco)

    2011-10-03

    Highlights: {center_dot} Polycrystalline materials with the tungsten bronze-type structure have been synthesized and characterized. {center_dot} Effect of the incorporation of rare earth ions and paramagnetic cations (Fe{sup 3+}) into a matrix ferroelectrically active was studied. {center_dot} Ferroelectric transition is pronounced by a large thermal hysteresis during the heating and cooling cycles. {center_dot} Phase transitions around T{sub c} were confirmed by differential scanning calorimetry (DSC) measurements. - Abstract: Polycrystalline materials with a general formula Pb{sub 2}Na{sub 0.8}R{sub 0.2}Nb{sub 4.8}Fe{sub 0.2}O{sub 15} (R = Dy, Eu, Sm, Nd, La) have been synthesized, in air by a high temperature solid state reaction method. X-ray diffraction study, at room temperature, revealed that they crystallize in the tungsten bronze-type structure. Dielectric properties were performed, in the temperature range 25-500 deg. C, at three different frequencies 10, 100 and 1000 kHz. The ferroelectric transition is pronounced by a large thermal hysteresis during the heating and cooling cycles. The determined Curie temperature values T{sub c} were discussed as a function of rare earth size. Phase transitions around T{sub c} for the investigated compounds were confirmed by differential scanning calorimetry (DSC) measurements.

  3. Structure, process, and outcomes of care in a telemonitoring program for patients with type 2 diabetes.

    Science.gov (United States)

    Nocella, Jill M; Dickson, Victoria Vaughan; Cleland, Charles M; Melkus, Gail D'Eramo

    2016-01-01

    Using Donabedian's structure-process-outcomes (SPO) framework, this descriptive, exploratory study examined the structure of a telemonitoring program in a population of patients with type 2 diabetes (T2D), the process of nurse-patient telephonic interactions, and patients' clinical outcomes. Secondary data analysis was conducted using data from 581 patients who participated in a home telemonitoring program for 12 months. Three point-biserial and six Pearson correlations were estimated to determine how patient demographics related to clinical characteristics. Mixed model regressions were conducted predicting hemoglobin A1c (HbA1c), systolic blood pressure (SBP), and diastolic blood pressure (DBP) levels at 6, 9, and 12 months based on the frequency of contact in the earlier 3 months. Analysis of variances were conducted to assess if the frequency of contact was significantly different by change in HbA1c levels from 3 to 6, 6 to 9, and 9 to 12 months. Significant negative correlations were found between age and HbA1c (r=-0.10, P=0.015) and DBP (r=-0.16, Ptelemonitoring environment assisted in understanding the effectiveness of this type of unique intervention and the need for further in-depth exploration of self-management techniques among individuals with T2D.

  4. DG-FEM solution for nonlinear wave-structure interaction using Boussinesq-type equations

    DEFF Research Database (Denmark)

    Engsig-Karup, Allan Peter; Hesthaven, Jan; Bingham, Harry B.

    2008-01-01

    We present a high-order nodal Discontinuous Galerkin Finite Element Method (DG-FEM) solution based on a set of highly accurate Boussinesq-type equations for solving general water-wave problems in complex geometries. A nodal DG-FEM is used for the spatial discretization to solve the Boussinesq equ...... and absorbed in the interior of the computational domain using a flexible relaxation technique applied on the free surface variables....... waters within the breaking limit. To demonstrate the current applicability of the model both linear and mildly nonlinear test cases are considered in two horizontal dimensions where the water waves interact with bottom-mounted fully reflecting structures. It is established that, by simple symmetry...... considerations combined with a mirror principle, it is possible to impose weak slip boundary conditions for both structured and general curvilinear wall boundaries while maintaining the accuracy of the scheme. As is standard for current high-order Boussinesq-type models, arbitrary waves can be generated...

  5. Characteristics of sandwich-type structural elements built of advanced composite materials from three dimensional fabrics

    Directory of Open Access Journals (Sweden)

    Castejón, L.

    1997-12-01

    Full Text Available Sandwich-type structures have proved to be alternatives of great success for several fields of application, and specially in the building sector. This is due to their outstanding properties of .specific rigidity and strength against bending loads and other range of advantages like fatigue and impact resistance, attainment of flat and smooth surfaces, high electric and thermal insulation, design versatility and some others. However, traditional sandwich structures present problems like their tendency towards delamination, stress concentrations in bores or screwed Joints, and pre resistance. These problems are alleviated thanks to the use of new sandwich structures built using three dimensional structures of advanced composite materials, maintaining the present advantages for more traditional sandwich structures. At this rate, these new structures can be applied in several areas where conventional sandwich structures used to be like walls, partitions, floor and ceiling structures, domes, vaults and dwellings, but with greater success.

    Las estructuras tipo sándwich han demostrado ser alternativas de gran éxito para diversos campos de aplicación y, en concreto, en el sector de la construcción, listo es gracias a sus excelentes propiedades de rigidez y resistencia específica frente a cargas de flexión y otra larga lista de ventajas, a la que pertenecen, por ejemplo, su buena resistencia a fatiga, resistencia al impacto, obtención de superficies lisas y suaves, elevado aislamiento térmico y eléctrico, versatilidad de diseño y otras. Sin embargo, las estructuras sándwich, tradicionales presentan una problemática consistente en su tendencia a la delaminación, concentraciones de tensiones ¿aparecidas ante la existencia de agujeros o uniones atornilladas y resistencia al fuego. Estos problemas son pifiados gracias a la aplicación de estructuras novedosas tipo sándwich, construidas a partir de tejidos tridimensionales de materiales

  6. Complex Regional Pain Syndrome Type I Affects Brain Structure in Prefrontal and Motor Cortex

    Science.gov (United States)

    Pleger, Burkhard; Draganski, Bogdan; Schwenkreis, Peter; Lenz, Melanie; Nicolas, Volkmar; Maier, Christoph; Tegenthoff, Martin

    2014-01-01

    The complex regional pain syndrome (CRPS) is a rare but debilitating pain disorder that mostly occurs after injuries to the upper limb. A number of studies indicated altered brain function in CRPS, whereas possible influences on brain structure remain poorly investigated. We acquired structural magnetic resonance imaging data from CRPS type I patients and applied voxel-by-voxel statistics to compare white and gray matter brain segments of CRPS patients with matched controls. Patients and controls were statistically compared in two different ways: First, we applied a 2-sample ttest to compare whole brain white and gray matter structure between patients and controls. Second, we aimed to assess structural alterations specifically of the primary somatosensory (S1) and motor cortex (M1) contralateral to the CRPS affected side. To this end, MRI scans of patients with left-sided CRPS (and matched controls) were horizontally flipped before preprocessing and region-of-interest-based group comparison. The unpaired ttest of the “non-flipped” data revealed that CRPS patients presented increased gray matter density in the dorsomedial prefrontal cortex. The same test applied to the “flipped” data showed further increases in gray matter density, not in the S1, but in the M1 contralateral to the CRPS-affected limb which were inversely related to decreased white matter density of the internal capsule within the ipsilateral brain hemisphere. The gray-white matter interaction between motor cortex and internal capsule suggests compensatory mechanisms within the central motor system possibly due to motor dysfunction. Altered gray matter structure in dorsomedial prefrontal cortex may occur in response to emotional processes such as pain-related suffering or elevated analgesic top-down control. PMID:24416397

  7. Complex structure of type VI peptidoglycan muramidase effector and a cognate immunity protein.

    Science.gov (United States)

    Wang, Tianyu; Ding, Jinjing; Zhang, Ying; Wang, Da-Cheng; Liu, Wei

    2013-10-01

    The type VI secretion system (T6SS) is a bacterial protein-export machine that is capable of delivering virulence effectors between Gram-negative bacteria. The T6SS of Pseudomonas aeruginosa transports two lytic enzymes, Tse1 and Tse3, to degrade cell-wall peptidoglycan in the periplasm of rival bacteria that are competing for niches via amidase and muramidase activities, respectively. Two cognate immunity proteins, Tsi1 and Tsi3, are produced by the bacterium to inactivate the two antibacterial effectors, thereby protecting its siblings from self-intoxication. Recently, Tse1-Tsi1 has been structurally characterized. Here, the structure of the Tse3-Tsi3 complex is reported at 1.9 Å resolution. The results reveal that Tse3 contains a C-terminal catalytic domain that adopts a soluble lytic transglycosylase (SLT) fold in which three calcium-binding sites were surprisingly observed close to the catalytic Glu residue. The electrostatic properties of the substrate-binding groove are also distinctive from those of known structures with a similar fold. All of these features imply that a unique catalytic mechanism is utilized by Tse3 in cleaving glycosidic bonds. Tsi3 comprises a single domain showing a β-sandwich architecture that is reminiscent of the immunoglobulin fold. Three loops of Tsi3 insert deeply into the groove of Tse3 and completely occlude its active site, which forms the structural basis of Tse3 inactivation. This work is the first crystallographic report describing the three-dimensional structure of the Tse3-Tsi3 effector-immunity pair.

  8. Complex regional pain syndrome type I affects brain structure in prefrontal and motor cortex.

    Directory of Open Access Journals (Sweden)

    Burkhard Pleger

    Full Text Available The complex regional pain syndrome (CRPS is a rare but debilitating pain disorder that mostly occurs after injuries to the upper limb. A number of studies indicated altered brain function in CRPS, whereas possible influences on brain structure remain poorly investigated. We acquired structural magnetic resonance imaging data from CRPS type I patients and applied voxel-by-voxel statistics to compare white and gray matter brain segments of CRPS patients with matched controls. Patients and controls were statistically compared in two different ways: First, we applied a 2-sample ttest to compare whole brain white and gray matter structure between patients and controls. Second, we aimed to assess structural alterations specifically of the primary somatosensory (S1 and motor cortex (M1 contralateral to the CRPS affected side. To this end, MRI scans of patients with left-sided CRPS (and matched controls were horizontally flipped before preprocessing and region-of-interest-based group comparison. The unpaired ttest of the "non-flipped" data revealed that CRPS patients presented increased gray matter density in the dorsomedial prefrontal cortex. The same test applied to the "flipped" data showed further increases in gray matter density, not in the S1, but in the M1 contralateral to the CRPS-affected limb which were inversely related to decreased white matter density of the internal capsule within the ipsilateral brain hemisphere. The gray-white matter interaction between motor cortex and internal capsule suggests compensatory mechanisms within the central motor system possibly due to motor dysfunction. Altered gray matter structure in dorsomedial prefrontal cortex may occur in response to emotional processes such as pain-related suffering or elevated analgesic top-down control.

  9. Complex regional pain syndrome type I affects brain structure in prefrontal and motor cortex.

    Science.gov (United States)

    Pleger, Burkhard; Draganski, Bogdan; Schwenkreis, Peter; Lenz, Melanie; Nicolas, Volkmar; Maier, Christoph; Tegenthoff, Martin

    2014-01-01

    The complex regional pain syndrome (CRPS) is a rare but debilitating pain disorder that mostly occurs after injuries to the upper limb. A number of studies indicated altered brain function in CRPS, whereas possible influences on brain structure remain poorly investigated. We acquired structural magnetic resonance imaging data from CRPS type I patients and applied voxel-by-voxel statistics to compare white and gray matter brain segments of CRPS patients with matched controls. Patients and controls were statistically compared in two different ways: First, we applied a 2-sample ttest to compare whole brain white and gray matter structure between patients and controls. Second, we aimed to assess structural alterations specifically of the primary somatosensory (S1) and motor cortex (M1) contralateral to the CRPS affected side. To this end, MRI scans of patients with left-sided CRPS (and matched controls) were horizontally flipped before preprocessing and region-of-interest-based group comparison. The unpaired ttest of the "non-flipped" data revealed that CRPS patients presented increased gray matter density in the dorsomedial prefrontal cortex. The same test applied to the "flipped" data showed further increases in gray matter density, not in the S1, but in the M1 contralateral to the CRPS-affected limb which were inversely related to decreased white matter density of the internal capsule within the ipsilateral brain hemisphere. The gray-white matter interaction between motor cortex and internal capsule suggests compensatory mechanisms within the central motor system possibly due to motor dysfunction. Altered gray matter structure in dorsomedial prefrontal cortex may occur in response to emotional processes such as pain-related suffering or elevated analgesic top-down control.

  10. Crystal structure of a monomeric thiolase-like protein type 1 (TLP1 from Mycobacterium smegmatis.

    Directory of Open Access Journals (Sweden)

    Neelanjana Janardan

    Full Text Available An analysis of the Mycobacterium smegmatis genome suggests that it codes for several thiolases and thiolase-like proteins. Thiolases are an important family of enzymes that are involved in fatty acid metabolism. They occur as either dimers or tetramers. Thiolases catalyze the Claisen condensation of two acetyl-Coenzyme A molecules in the synthetic direction and the thiolytic cleavage of 3-ketoacyl-Coenzyme A molecules in the degradative direction. Some of the M. smegmatis genes have been annotated as thiolases of the poorly characterized SCP2-thiolase subfamily. The mammalian SCP2-thiolase consists of an N-terminal thiolase domain followed by an additional C-terminal domain called sterol carrier protein-2 or SCP2. The M. smegmatis protein selected in the present study, referred to here as the thiolase-like protein type 1 (MsTLP1, has been biochemically and structurally characterized. Unlike classical thiolases, MsTLP1 is a monomer in solution. Its structure has been determined at 2.7 Å resolution by the single wavelength anomalous dispersion method. The structure of the protomer confirms that the N-terminal domain has the thiolase fold. An extra C-terminal domain is indeed observed. Interestingly, it consists of six β-strands forming an anti-parallel β-barrel which is completely different from the expected SCP2-fold. Detailed sequence and structural comparisons with thiolases show that the residues known to be essential for catalysis are not conserved in MsTLP1. Consistent with this observation, activity measurements show that MsTLP1 does not catalyze the thiolase reaction. This is the first structural report of a monomeric thiolase-like protein from any organism. These studies show that MsTLP1 belongs to a new group of thiolase related proteins of unknown function.

  11. Detailed Structures of Hexagonal Diamond (lonsdaleite) and Wurtzite-type BN

    Science.gov (United States)

    Yoshiasa, Akira; Murai, Yu; Ohtaka, Osamu; Katsura, Tomoo

    2003-04-01

    Hexagonal diamond (hDIA) and wurtzite-type BN (wBN) powders were synthesized using a Kawai-type high-pressure apparatus and the essential details of their structures were examined by Reitveld refinements in order to investigate their thermodynamic stability and transition mechanism. X-ray diffraction profiles of the products were well explained by a mixture of hDIA and cubic diamond (cDIA) with stacking faults. The mass fraction of hDIA and cDIA was 50:50 for the products annealed between 800 and 1400°C and it became 20:80 for the product annealed at 1600°C. Temperatures higher than 1600°C seem to favor the formation of cDIA or to induce the conversion from hDIA to cDIA. Structure refinement revealed that a decrease and an increase in the basal and apical distances of C-C and B-N bonds in hDIA and wBN, respectively, are introduced by lowering the symmetry from cubic to hexagonal. Since the relative stability of wurtzite-type compounds largely depends on the distortion of the tetrahedral bond angle, the deviation from the ideal tetrahedron in both hDIA and wBN was refined to discuss their stability. The transition mechanism from graphite and graphite-like BN to hDIA and wBN is discussed by comparing the present results and those of previous simulation studies. Based on analogous features observed in the synthetic hDIA and lonsdaleite (natural hDIA found in meteorites), the formation mechanism of hDIA in meteorites is proposed.

  12. Stellar Photometric Structures of the Host Galaxies of Nearby Type 1 Active Galactic Nuclei

    Science.gov (United States)

    Kim, Minjin; Ho, Luis C.; Peng, Chien Y.; Barth, Aaron J.; Im, Myungshin

    2017-10-01

    We present detailed image analysis of rest-frame optical images of 235 low-redshift (z ≲ 0.35) Type 1 active galactic nuclei (AGNs) observed with the Hubble Space Telescope. The high-resolution images enable us to perform rigorous two-dimensional image modeling to decouple the luminous central point source from the host galaxy, which, when warranted, is further decomposed into its principal structural components (bulge, bar, and disk). In many cases, care must be taken to account for structural complexities such as spiral arms, tidal features, and overlapping or interacting companion galaxies. We employ Fourier modes to characterize the degree of asymmetry of the light distribution of the stars as a quantitative measure of morphological distortion due to interactions or mergers. We examine the dependence of the physical parameters of the host galaxies on the properties of the AGNs, namely, radio-loudness and the width of the broad emission lines. In accordance with previous studies, narrow-line (Hβ FWHM ≤ 2000 km s-1) Type 1 AGNs, in contrast to their broad-line (Hβ FWHM > 2000 km s-1) counterparts, are preferentially hosted in later-type, lower-luminosity galaxies, which have a higher incidence of pseudo-bulges, are more frequently barred, and are less morphologically disturbed. This suggests that narrow-line Type 1 AGNs experienced a more quiescent evolutionary history driven primarily by internal secular evolution instead of external dynamical perturbations. The fraction of AGN hosts showing merger signatures is larger for more luminous sources. Radio-loud AGNs generally preferentially live in earlier-type (bulge-dominated), more massive hosts, although a minority of them appear to contain a significant disk component. We do not find convincing evidence for enhanced merger signatures in the radio-loud population. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute

  13. Structural and electronic properties of effective p-type doping WS2 monolayers: A computational study

    Science.gov (United States)

    Li, Ning; Liu, Zhengtang; Hu, Shengliang; Wang, Huiqi

    2018-01-01

    Using first-principles calculations within density functional theory, we systematically investigated the structural and electronic properties of Metal (Me = Al, Ga, In, Tl, V, Nb, Ta)-doped WS2 monolayers. The impurity states induced by Me substitutional doping are closed to the valence band, showing the p-type characteristic of Me-doped WS2 monolayers. Among Me dopants, Nb-doped WS2 monolayer has the lowest formation energy and slightly local distortion. Subsequently, the covalent character of Wsbnd S bond in Nb-doped WS2 monolayer increases compared with pure WS2 monolayer. It is noteworthy that the feature of direct band gap is still presented in (V-Ta)-doped WS2 monolayers, which is very conducive to microelectronic and optoelectronic applications. Therefore, Nb is the appropriate p-type dopant for the WS2 monolayers based on the present work. These findings may prove to be instrumental in the future design of new p-type conducive WS2 monolayers.

  14. PM2.5 Concentration Differences between Various Forest Types and Its Correlation with Forest Structure

    Directory of Open Access Journals (Sweden)

    Xuhui Liu

    2015-11-01

    Full Text Available The Plain Forestation Project is an important measure designed to alleviate air pollution in Beijing, the capital of China. Ten commonly cultivated forest types of the Plain Forestation Project were studied at three growth stages of leaves. The particulate matter (PM2.5 concentrations and forest structures were surveyed to analyze the PM2.5 concentration differences between different forest types, and establish a linear relationship between forest structures and PM2.5 concentration differences. The results suggested that forest ecosystems can block and capture PM2.5 from the air. Forests with luxuriant foliage are most effective in removing PM2.5 from the air. The average PM2.5 mass concentration in the Leaf-on Period (LOP was the lowest when compared with other periods. The PM2.5 concentrations in the forest usually were higher than the control. Correspondingly, PM2.5 concentration indexes were negative values during daytime, but this results were reversed at night. Forests can reduce the diffusion rate of PM2.5 leading to PM2.5 were detained in the forest during daytime, and play an important role in the adsorption or deposition of particulate matter at night. Forest structure was primary reason of the PM2.5 concentration difference between different forests. The PM2.5 concentration index was positively correlated to canopy density, leaf area index (LAI, and mean diameter at breast height (DBH, and negatively correlated to the average tree height (height, forestland area, grass coverage and height.

  15. Structural and dynamic properties that govern the stability of an engineered fibronectin type III domain

    Science.gov (United States)

    Porebski, Benjamin T.; Nickson, Adrian A.; Hoke, David E.; Hunter, Morag R.; Zhu, Liguang; McGowan, Sheena; Webb, Geoffrey I.; Buckle, Ashley M.

    2015-01-01

    Consensus protein design is a rapid and reliable technique for the improvement of protein stability, which relies on the use of homologous protein sequences. To enhance the stability of a fibronectin type III (FN3) domain, consensus design was employed using an alignment of 2123 sequences. The resulting FN3 domain, FN3con, has unprecedented stability, with a melting temperature >100°C, a ΔGD−N of 15.5 kcal mol−1 and a greatly reduced unfolding rate compared with wild-type. To determine the underlying molecular basis for stability, an X-ray crystal structure of FN3con was determined to 2.0 Å and compared with other FN3 domains of varying stabilities. The structure of FN3con reveals significantly increased salt bridge interactions that are cooperatively networked, and a highly optimized hydrophobic core. Molecular dynamics simulations of FN3con and comparison structures show the cooperative power of electrostatic and hydrophobic networks in improving FN3con stability. Taken together, our data reveal that FN3con stability does not result from a single mechanism, but rather the combination of several features and the removal of non-conserved, unfavorable interactions. The large number of sequences employed in this study has most likely enhanced the robustness of the consensus design, which is now possible due to the increased sequence availability in the post-genomic era. These studies increase our knowledge of the molecular mechanisms that govern stability and demonstrate the rising potential for enhancing stability via the consensus method. PMID:25691761

  16. Local structure and oxide-ion conduction mechanism in apatite-type lanthanum silicates.

    Science.gov (United States)

    Masson, Olivier; Berghout, Abid; Béchade, Emilie; Jouin, Jenny; Thomas, Philippe; Asaka, Toru; Fukuda, Koichiro

    2017-01-01

    The local structure of apatite-type lanthanum silicates of general formula La9.33+x(SiO4)6O2+3x/2 has been investigated by combining the atomic pair distribution function (PDF) method, conventional X-ray and neutron powder diffraction (NPD) data and density functional theory (DFT) calculations. DFT was used to build structure models with stable positions of excess oxide ions within the conduction channel. Two stable interstitial positions were obtained in accordance with literature, the first one located at the very periphery of the conduction channel, neighbouring the SiO4 tetrahedral units, and the second one closer to the channel axis. The corresponding PDFs and average structures were then calculated and tested against experimental PDFs obtained by X-ray total scattering and NPD Rietveld refinements results gathered from literature. It was shown that of the two stable interstitial positions obtained with DFT only the second one located within the channel is consistent with experimental data. This result consolidates one of the two main conduction mechanisms along the c-axis reported in the literature, namely the one involving cooperative movement of O4 and Oi ions.

  17. Type IV pilus proteins form an integrated structure extending from the cytoplasm to the outer membrane.

    Directory of Open Access Journals (Sweden)

    Chengyun Li

    Full Text Available The bacterial type IV pilus (T4P is the strongest biological motor known to date as its retraction can generate forces well over 100 pN. Myxococcus xanthus, a δ-proteobacterium, provides a good model for T4P investigations because its social (S gliding motility is powered by T4P. In this study, the interactions among M. xanthus T4P proteins were investigated using genetics and the yeast two-hybrid (Y2H system. Our genetic analysis suggests that there is an integrated T4P structure that crosses the inner membrane (IM, periplasm and the outer membrane (OM. Moreover, this structure exists in the absence of the pilus filament. A systematic Y2H survey provided evidence for direct interactions among IM and OM proteins exposed to the periplasm. For example, the IM lipoprotein PilP interacted with its cognate OM protein PilQ. In addition, interactions among T4P proteins from the thermophile Thermus thermophilus were investigated by Y2H. The results indicated similar protein-protein interactions in the T4P system of this non-proteobacterium despite significant sequence divergence between T4P proteins in T. thermophilus and M. xanthus. The observations here support the model of an integrated T4P structure in the absence of a pilus in diverse bacterial species.

  18. Elaboration in type, primary structure, and bioactivity of polysaccharides derived from mollusks.

    Science.gov (United States)

    Wang, Ling Chong; Di, Liu Qing; Li, Jun Song; Hu, Li Hong; Cheng, Jian Ming; Wu, Hao

    2017-10-17

    Over the past decades, numerous Mollusca species have received more attention in development and utilization as valuable bio-resources. Many efforts have been focused on investigating mollusk polysaccharides because of their rich content, ease of extraction, diversified sorts, specific structure, various biofunctions and potent activities. To date, many mollusks, especially species of gastropods, bivalves, or cephalopods, have been reported containing polysaccharide compounds in tissues with abundant amount, and most of polysaccharides are obtainable through combining techniques of extraction, separation and purification. The polysaccharides isolated from mollusks appeared with various structural and physicochemical characteristics, ranged from neutral polysaccharides and sulfated polysaccharides, to GAGs series (including Hep/HS, CS/DS, HA and similarities), even to heterogeneous glycan with high molecular weight. This review article provides comprehensive knowledge of recent researches on type classification, tissue origins and possible biofunctions of various polysaccharides from mollusks. The highlights were placed in structure variation including molecular weight, sulfation pattern, linkages and monomer compositions for repeating unit, and primary molecular construction of the mollusks polysaccharides. In addition, this article covers general information on exhibition of mollusks polysaccharide extracts or preparations in the various bioactivities, such as anticoagulant, antiatherogenic, antioxidant, immunomodulatory, antivirus and antitumor activities, which would reveal their possible potentials in medical application. Furthermore, the article presents a brief overview on several challenges and future scope in this field.

  19. The comparative study of craniofacial structural characteristic of individuals with different types of cleft palate.

    Science.gov (United States)

    Lu, Da-wei; Shi, Bing; Wang, Heng-jian; Zheng, Qian

    2007-10-01

    To compare craniofacial structural characteristic of individuals with different types of cleft palate and to lay a foundation for better treatment protocol for patients with cleft palate, we chose a sample consisting of 12 patients with Treacher Collin syndrome, 15 patients with Pierre Robin sequence, 40 patients with unilateral complete cleft lip and palate, and 40 patients with isolated cleft palate who met certain criteria. Lateral cephalometric radiographs were obtained from each subject. A total of 22 variables, comprising 11 angular, 9 linear, and 2 ratio measurements, were studied. The z-scores were analyzed during paired Student t test. The data showed us that there seems to be no difference in craniofacial structures between patients with isolated cleft palate and normal persons. Patients with unilateral complete cleft lip and palate who had only cleft lip repaired exhibit such characteristics as midface retrusion, relatively excessive lower facial height, and more obtuse gonial angle. The cranial base areas of individuals with Treacher Collin syndrome and Pierre Robin sequence are similar to those of normal persons. Mandibular hypoplasia in both vertical and horizontal dimensions and maxillary retrusion can be found in patients with Treacher Collin syndrome, while only mandibular hypoplasia in the horizontal dimension can be found in patients with Pierre Robin sequence. The developmental deficiency of craniofacial structures seems to be a separate deformity, not the direct outcome of cleft palate defect.

  20. Optimization of chemical structure of Schottky-type selection diode for crossbar resistive memory.

    Science.gov (United States)

    Kim, Gun Hwan; Lee, Jong Ho; Jeon, Woojin; Song, Seul Ji; Seok, Jun Yeong; Yoon, Jung Ho; Yoon, Kyung Jean; Park, Tae Joo; Hwang, Cheol Seong

    2012-10-24

    The electrical performances of Pt/TiO(2)/Ti/Pt stacked Schottky-type diode (SD) was systematically examined, and this performance is dependent on the chemical structures of the each layer and their interfaces. The Ti layers containing a tolerable amount of oxygen showed metallic electrical conduction characteristics, which was confirmed by sheet resistance measurement with elevating the temperature, transmission line measurement (TLM), and Auger electron spectroscopy (AES) analysis. However, the chemical structure of SD stack and resulting electrical properties were crucially affected by the dissolved oxygen concentration in the Ti layers. The lower oxidation potential of the Ti layer with initially higher oxygen concentration suppressed the oxygen deficiency of the overlying TiO(2) layer induced by consumption of the oxygen from TiO(2) layer. This structure results in the lower reverse current of SDs without significant degradation of forward-state current. Conductive atomic force microscopy (CAFM) analysis showed the current conduction through the local conduction paths in the presented SDs, which guarantees a sufficient forward-current density as a selection device for highly integrated crossbar array resistive memory.

  1. Structure of a bacterial type III secretion system in contact with a host membrane in situ

    Science.gov (United States)

    Nans, Andrea; Kudryashev, Mikhail; Saibil, Helen R.; Hayward, Richard D.

    2015-12-01

    Many bacterial pathogens of animals and plants use a conserved type III secretion system (T3SS) to inject virulence effector proteins directly into eukaryotic cells to subvert host functions. Contact with host membranes is critical for T3SS activation, yet little is known about T3SS architecture in this state or the conformational changes that drive effector translocation. Here we use cryo-electron tomography and sub-tomogram averaging to derive the intact structure of the primordial Chlamydia trachomatis T3SS in the presence and absence of host membrane contact. Comparison of the averaged structures demonstrates a marked compaction of the basal body (4 nm) occurs when the needle tip contacts the host cell membrane. This compaction is coupled to a stabilization of the cytosolic sorting platform-ATPase. Our findings reveal the first structure of a bacterial T3SS from a major human pathogen engaged with a eukaryotic host, and reveal striking `pump-action' conformational changes that underpin effector injection.

  2. Structural variations of staphylococcal cassette chromosome mec Type IVa in Staphylococcus aureus clonal complex 8 and unrelated lineages

    DEFF Research Database (Denmark)

    Damborg, Peter Panduro; Bartels, Mette Damkjær; Boye, Kit

    2011-01-01

    PCR mapping of staphylococcal cassette chromosome mec type IVa and adjacent mobile elements in 94 methicillin-resistant Staphylococcus aureus (MRSA) strains identified two primary structures (A and B) that could be further classified into two (A1 and A2) and five (B1 to B5) variants, primarily...... based on structural differences in the orfX-J3 region. While spa type t008 (USA300) invariably contained the A variants, other spa types belonging to clonal complex 8 and unrelated lineages generally contained B variants. These findings have important implications for the typing and identification...

  3. Some design constraints required for the assembly of software components: The incorporation of atomic abstract types into generically structured abstract types

    Science.gov (United States)

    Johnson, Charles S.

    1986-01-01

    It is nearly axiomatic, that to take the greatest advantage of the useful features available in a development system, and to avoid the negative interactions of those features, requires the exercise of a design methodology which constrains their use. A major design support feature of the Ada language is abstraction: for data, functions processes, resources, and system elements in general. Atomic abstract types can be created in packages defining those private types and all of the overloaded operators, functions, and hidden data required for their use in an application. Generically structured abstract types can be created in generic packages defining those structured private types, as buildups from the user-defined data types which are input as parameters. A study is made of the design constraints required for software incorporating either atomic or generically structured abstract types, if the integration of software components based on them is to be subsequently performed. The impact of these techniques on the reusability of software and the creation of project-specific software support environments is also discussed.

  4. Structure and Conceptual Design of a Water-Hammering-Type Honsang for Restoration

    Directory of Open Access Journals (Sweden)

    Yong Sam Lee

    2012-06-01

    Full Text Available We analyzed the manufacturing procedure, specifications, repair history, and details of celestial movements of the water-hammering type Honsang (celestial globe. Results from our study on the remaining Honsangs in China and Japan and on the reconstruction models in Korea were applied to our conceptual design of the water-hammering type Honsang. A Honui (armillary sphere and Honsang using the water-hammering method were manufactured in Joseon in 1435 (the 17th year of King Sejong. Jang Yeong-Sil developed the Honsang system based on the water-operation method of Shui yün i hsiang t’ai in China. Water-operation means driving water wheels using a water flow. The most important factor in this type of operation is the precision of the water clock and the control of the water wheel movement. The water-hammering type Honsang in Joseon probably adopted the Cheonhyeong (天衡; oriental escapement device system of Shui yün i hsiang t’ai in China and the overflow mechanism of Jagyeongnu (striking clepsydra in Joseon, etc. In addition to the Cheonryun system, more gear instruments were needed to stage the rotation of the Honsang globe and the sun’s movement. In this study, the water-hammering mechanism is analyzed in the structure of a water clock, a water wheel, the Cheonhyeong system, and the Giryun system, as an organically working operation mechanism. We expect that this study will serve as an essential basis for studies on Heumgyeonggaknu, the water-operating astronomical clock, and other astronomical clocks in the middle and latter parts of the Joseon dynasty.

  5. Remote Sensing of plant functional types: Relative importance of biochemical and structural plant traits

    Science.gov (United States)

    Kattenborn, Teja; Schmidtlein, Sebastian

    2017-04-01

    Monitoring ecosystems is a key priority in order to understand vegetation patterns, underlying resource cycles and changes their off. Driven by biotic and abiotic factors, plant species within an ecosystem are likely to share similar structural, physiological or phenological traits and can therefore be grouped into plant functional types (PFT). It can be assumed that plants which share similar traits also share similar optical characteristics. Therefore optical remote sensing was identified as a valuable tool for differentiating PFT. Although several authors list structural and biochemical plant traits which are important for differentiating PFT using hyperspectral remote sensing, there is no quantitative or qualitative information on the relative importance of these traits. Thus, little is known about the explicit role of plant traits for an optical discrimination of PFT. One of the main reasons for this is that various optical traits affect the same wavelength regions and it is therefore difficult to isolate the discriminative power of a single trait. A way to determine the effect of single plant traits on the optical reflectance of plant canopies is given by radiative transfer models. The most established radiative transfer model is PROSAIL, which incorporates biochemical and structural plant traits, such as pigment contents or leaf area index. In the present study 25 grassland species of different PFT were cultivated and traits relevant for PROSAIL were measured for the entire vegetation season of 2016. The information content of each trait for differentiating PFTs was determined by applying a Multi-response Permutation Procedure on the actual traits, as well as on simulated canopy spectra derived from PROSAIL. According to our results some traits, especially biochemical traits, show a weaker separability of PFT on a spectral level than compared to the actual trait measurements. Overall structural traits (leaf angle and leaf area index) are more important for

  6. Machine-Thermal Coupling Stresses Analysis of the Fin-Type Structural Thermoelectric Generator

    Science.gov (United States)

    Zhang, Zheng; Yue, Hao; Chen, Dongbo; Qin, Delei; Chen, Zijian

    2017-05-01

    The design structure and heat-transfer mechanism of a thermoelectric generator (TEG) determine its body temperature state. Thermal stress and thermal deformation generated by the temperature variation directly affect the stress state of thermoelectric modules (TEMs). Therefore, the rated temperature and pressing force of TEMs are important parameters in TEG design. Here, the relationships between structural of a fin-type TEG (FTEG) and these parameters are studied by modeling and "machine-thermal" coupling simulation. An indirect calculation method is adopted in the coupling simulation. First, numerical heat transfer calculations of a three-dimensional FTEG model are conducted according to an orthogonal simulation table. The influences of structural parameters for heat transfer in the channel and outer fin temperature distribution are analyzed. The optimal structural parameters are obtained and used to simulate temperature field of the outer fins. Second, taking the thermal calculation results as the initial condition, the thermal-solid coupling calculation is adopted. The thermal stresses of outer fin, mechanical force of spring-angle pressing mechanism, and clamping force on a TEM are analyzed. The simulation results show that the heat transfer area of the inner fin and the physical parameters of the metal materials are the keys to determining the FTEG temperature field. The pressing mechanism's mechanical force can be reduced by reducing the outer fin angle. In addition, a corrugated cooling water pipe, which has cooling and spring functionality, is conducive to establishing an adaptable clamping force to avoid the TEMs being crushed by the thermal stresses in the body.

  7. Evidence for alternative quaternary structure in a bacterial Type III secretion system chaperone

    Directory of Open Access Journals (Sweden)

    Picking Wendy L

    2010-07-01

    Full Text Available Abstract Background Type III secretion systems are a common virulence mechanism in many Gram-negative bacterial pathogens. These systems use a nanomachine resembling a molecular needle and syringe to provide an energized conduit for the translocation of effector proteins from the bacterial cytoplasm to the host cell cytoplasm for the benefit of the pathogen. Prior to translocation specialized chaperones maintain proper effector protein conformation. The class II chaperone, Invasion plasmid gene (Ipg C, stabilizes two pore forming translocator proteins. IpgC exists as a functional dimer to facilitate the mutually exclusive binding of both translocators. Results In this study, we present the 3.3 Å crystal structure of an amino-terminally truncated form (residues 10-155, denoted IpgC10-155 of the class II chaperone IpgC from Shigella flexneri. Our structure demonstrates an alternative quaternary arrangement to that previously described for a carboxy-terminally truncated variant of IpgC (IpgC1-151. Specifically, we observe a rotationally-symmetric "head-to- head" dimerization interface that is far more similar to that previously described for SycD from Yersinia enterocolitica than to IpgC1-151. The IpgC structure presented here displays major differences in the amino terminal region, where extended coil-like structures are seen, as opposed to the short, ordered alpha helices and asymmetric dimerization interface seen within IpgC1-151. Despite these differences, however, both modes of dimerization support chaperone activity, as judged by a copurification assay with a recombinant form of the translocator protein, IpaB. Conclusions From primary to quaternary structure, these results presented here suggest that a symmetric dimerization interface is conserved across bacterial class II chaperones. In light of previous data which have described the structure and function of asymmetric dimerization, our results raise the possibility that class II

  8. Evidence for alternative quaternary structure in a bacterial Type III secretion system chaperone

    Energy Technology Data Exchange (ETDEWEB)

    Barta, Michael L.; Zhang, Lingling; Picking, Wendy L.; Geisbrecht, Brian V. (UMKC); (OKLU)

    2010-10-05

    Type III secretion systems are a common virulence mechanism in many Gram-negative bacterial pathogens. These systems use a nanomachine resembling a molecular needle and syringe to provide an energized conduit for the translocation of effector proteins from the bacterial cytoplasm to the host cell cytoplasm for the benefit of the pathogen. Prior to translocation specialized chaperones maintain proper effector protein conformation. The class II chaperone, Invasion plasmid gene (Ipg) C, stabilizes two pore forming translocator proteins. IpgC exists as a functional dimer to facilitate the mutually exclusive binding of both translocators. In this study, we present the 3.3 {angstrom} crystal structure of an amino-terminally truncated form (residues 10-155, denoted IpgC10-155) of the class II chaperone IpgC from Shigella flexneri. Our structure demonstrates an alternative quaternary arrangement to that previously described for a carboxy-terminally truncated variant of IpgC (IpgC{sup 1-151}). Specifically, we observe a rotationally-symmetric 'head-to-head' dimerization interface that is far more similar to that previously described for SycD from Yersinia enterocolitica than to IpgC1-151. The IpgC structure presented here displays major differences in the amino terminal region, where extended coil-like structures are seen, as opposed to the short, ordered alpha helices and asymmetric dimerization interface seen within IpgC{sup 1-151}. Despite these differences, however, both modes of dimerization support chaperone activity, as judged by a copurification assay with a recombinant form of the translocator protein, IpaB. Conclusions: From primary to quaternary structure, these results presented here suggest that a symmetric dimerization interface is conserved across bacterial class II chaperones. In light of previous data which have described the structure and function of asymmetric dimerization, our results raise the possibility that class II chaperones may

  9. The common structural architecture of Shigella flexneri and Salmonella typhimurium type three secretion needles.

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Demers

    2013-03-01

    Full Text Available The Type Three Secretion System (T3SS, or injectisome, is a macromolecular infection machinery present in many pathogenic Gram-negative bacteria. It consists of a basal body, anchored in both bacterial membranes, and a hollow needle through which effector proteins are delivered into the target host cell. Two different architectures of the T3SS needle have been previously proposed. First, an atomic model of the Salmonella typhimurium needle was generated from solid-state NMR data. The needle subunit protein, PrgI, comprises a rigid-extended N-terminal segment and a helix-loop-helix motif with the N-terminus located on the outside face of the needle. Second, a model of the Shigella flexneri needle was generated from a high-resolution 7.7-Å cryo-electron microscopy density map. The subunit protein, MxiH, contains an N-terminal α-helix, a loop, another α-helix, a 14-residue-long β-hairpin (Q51-Q64 and a C-terminal α-helix, with the N-terminus facing inward to the lumen of the needle. In the current study, we carried out solid-state NMR measurements of wild-type Shigella flexneri needles polymerized in vitro and identified the following secondary structure elements for MxiH: a rigid-extended N-terminal segment (S2-T11, an α-helix (L12-A38, a loop (E39-P44 and a C-terminal α-helix (Q45-R83. Using immunogold labeling in vitro and in vivo on functional needles, we located the N-terminus of MxiH subunits on the exterior of the assembly, consistent with evolutionary sequence conservation patterns and mutagenesis data. We generated a homology model of Shigella flexneri needles compatible with both experimental data: the MxiH solid-state NMR chemical shifts and the state-of-the-art cryoEM density map. These results corroborate the solid-state NMR structure previously solved for Salmonella typhimurium PrgI needles and establish that Shigella flexneri and Salmonella typhimurium subunit proteins adopt a conserved structure and orientation in their

  10. Hypothetical planar and nanotubular crystalline structures with five interatomic bonds of Kepler nets type

    Science.gov (United States)

    Kochaev, Aleksey I.

    2017-02-01

    The possibility of metastable existence of planar and non-chiral nanotubular crystalline lattices in the form of Kepler nets of 34324, 3342, and 346 types (the notations are given in Schläfly symbols), using ab initio calculations, has researched. Atoms of P, As, Sb, Bi from 15th group and atoms of S, Se, Te from 16th group of the periodic table were taken into consideration. The lengths of interatomic bonds corresponding to the steadiest states for such were determined. We found that among these new composed structures crystals encountered strong elastic properties. Besides, some of them can possess pyroelectric and piezoelectric properties. Our results can be used for nanoelectronics and nanoelectromechanical devices designing.

  11. Hypothetical planar and nanotubular crystalline structures with five interatomic bonds of Kepler nets type

    Directory of Open Access Journals (Sweden)

    Aleksey I. Kochaev

    2017-02-01

    Full Text Available The possibility of metastable existence of planar and non-chiral nanotubular crystalline lattices in the form of Kepler nets of 34324, 3342, and 346 types (the notations are given in Schläfly symbols, using ab initio calculations, has researched. Atoms of P, As, Sb, Bi from 15th group and atoms of S, Se, Te from 16th group of the periodic table were taken into consideration. The lengths of interatomic bonds corresponding to the steadiest states for such were determined. We found that among these new composed structures crystals encountered strong elastic properties. Besides, some of them can possess pyroelectric and piezoelectric properties. Our results can be used for nanoelectronics and nanoelectromechanical devices designing.

  12. Structural differences between wild-type and fish eye disease mutant of lecithin:cholesterol acyltransferase.

    Science.gov (United States)

    Reshetnyak, Yana; Tchedre, Kissaou T; Nair, Maya P; Pritchard, P Haydn; Lacko, Andras G

    2006-08-01

    Fluorescence spectroscopy has been used to investigate the conformational changes that occur upon binding of wild type (WT) and mutant (Thr123Ile) lecithin:cholesterol acyltransferase (LCAT) to the potential substrates (dioleoyl-phosphatidyl choline [DOPC] and high density lipoprotein [HDL]). For a detailed analysis of structural differences between WT and mutant LCAT, we performed decompositional analysis of a set of tryptophan fluorescence spectra, measured at increasing concentrations of external quenchers (acrylamide and KI). The data obtained show that Thr123Ile mutation in LCAT leads to a conformation that is likely to be more rigid (less mobile/flexible) than that of the WT protein with a redistribution of charged residues around exposed tryptophan fluorophores. We propose that the redistribution of charged residues in mutant LCAT may be a major factor responsible for the dramatically reduced activity of the enzyme with HDL and reconstituted high density lipoprotein (rHDL).

  13. Four types of interference competition and their impacts on the ecology and evolution of size-structured populations and communities.

    Science.gov (United States)

    Zhang, Lai; Andersen, Ken H; Dieckmann, Ulf; Brännström, Åke

    2015-09-07

    We investigate how four types of interference competition - which alternatively affect foraging, metabolism, survival, and reproduction - impact the ecology and evolution of size-structured populations. Even though all four types of interference competition reduce population biomass, interference competition at intermediate intensity sometimes significantly increases the abundance of adult individuals and the population׳s reproduction rate. We find that foraging and metabolic interference evolutionarily favor smaller maturation size when interference is weak and larger maturation size when interference is strong. The evolutionary response to survival interference and reproductive interference is always larger maturation size. We also investigate how the four types of interference competition impact the evolutionary dynamics and resultant diversity and trophic structure of size-structured communities. Like other types of trait-mediated competition, all four types of interference competition can induce disruptive selection and thus promote initial diversification. Even though foraging interference and reproductive interference are more potent in promoting initial diversification, they catalyze the formation of diverse communities with complex trophic structure only at high levels of interference intensity. By contrast, survival interference does so already at intermediate levels, while reproductive interference can only support relatively smaller communities with simpler trophic structure. Taken together, our results show how the type and intensity of interference competition jointly affect coexistence patterns in structured population models. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Efficiency of different forest types in carbon storage depends on their internal structure

    Directory of Open Access Journals (Sweden)

    Iuliana F. Gheorghe

    2011-01-01

    Full Text Available Forest vegetation is a key factor in the maintenance of global carbon cycle balance under the present climate change conditions. Forest ecosystems are both buffers against extreme climatic events accompanying climate change and carbon sinks diminishing the environmental impact of anthropogenic greenhouse gas emissions. We investigated the influence of stand structure and site characteristics on the productivity and carbon storage capacity of temperate forest types. Predictors of species productivity were parameters such as stand density, age, height, average diameter and wood density. Morus alba (L. was more productive than average both in terms of annual volume increment and annual biomass gain, while Quercus sessiliflora (Matt. Lieb. and Quercus frainetto (Ten. were significantly less productive than average. Differences in stand productivity were explained by stand density, age, height, altitude, type of regeneration and species composition. Statistically significant differences were measured between the productivity of stands dominated by different woody species, with low productive stands dominated by slow growing species with high wood density like Quercus or Fagus, and highly productive stands rich in fast growing species with low wood density like Populus or Salix. Stands with different plant communities in the underlying herbaceous layer also tended to have different levels of productivity.

  15. Overlapping and independent structural roles for human papillomavirus type 16 L2 conserved cysteines.

    Science.gov (United States)

    Conway, Michael J; Alam, Samina; Christensen, Neil D; Meyers, Craig

    2009-10-25

    Cryoelectron microscopy images of HPV16 pseudovirions (PsV) depict that each pentamer of L1 can be occluded with a monomer of L2. Further research suggests that an N-terminal external loop of L2 exists, which is the target of neutralizing and cross-neutralizing antibodies. Here we show that N-terminal L2 cysteine residues, Cys22 and Cys28, have overlapping and independent structural roles, which affect both early- and late-stage assembly events. Substitution of either cysteine residue enhances infectivity markedly in comparison to wild-type HPV16. However, only Cys22Ser 20-day virions become nearly as stable as wild type. In addition, Cys22Ser, and Cys22,28Ser 20-day virions have lost their susceptibility to neutralization by anti-L2 antibodies, whereas Cys28Ser 20-day virions remain partially susceptible. These results suggest that Cys28 is necessary for late-stage stabilization of capsids, while Cys22 is necessary for proper display of L2 neutralizing epitopes.

  16. Electrical and Structural Analysis on the Formation of n-type Junction in Germanium

    Science.gov (United States)

    Aziz, Umar Abdul; Nadhirah Mohamad Rashid, Nur; Rahmah Aid, Siti; Centeno, Anthony; Ikenoue, Hiroshi; Xie, Fang

    2017-05-01

    Germanium (Ge) has re-emerged as a potential candidate to replace silicon (Si) as a substrate, due to its higher carrier mobility properties that are the key point for the realization of devices high drive current. However, the fabrication process of Ge is confronted with many problems such as low dopant electrical activation and the utilization of heavy n-type dopant atoms during ion implantation. These problems result in more damage and defects that can affect dopant activation. This paper reports the electrical and structural analysis on the formation of n-type junction in Ge substrate by ion implantation, followed by excimer laser annealing (ELA) using KrF laser. ELA parameters such as laser fluences were varied from 100 - 2000 mJ/cm2 and shot number between 1 - 1000 to obtain the optimized parameter of ELA with a high degree of damage and defect removal. Low resistance with a high degree of crystallinity is obtained for the samples annealed with less than five shot number. Higher shot number with high laser fluence, shows a high degree of ablation damage.

  17. G33.6 + 0.1 - A shell type supernova remnant with unusual structure

    Science.gov (United States)

    Velusamy, T.; Becker, R. H.; Seward, F. D.

    1991-01-01

    The morphology of Supernova Remnant G33.6 + 0.1 (Kes 79) has been studied in the X-rays with Einstein and in the radio wavelengths using the VLA. Multifrequency high resolution observations of the VLA at 327, 1500, and 5000 MHz are used to study the radio spectrum and polarization. The radio emission shows well formed outer shell structure and very bright central emission. Although the overall distribution of spectral index (about -0.6 to -0.75) is consistent with that of shell type remnants, the bright filamentary emission along the 'inner ring' has relatively flatter spectrum (alpha about -0.4). Both radio and X-rays show strong central emission; existence of a plerion near the center cannot be ruled out. The X-ray image does not show the characteristic limb brightening for shell type SNRs. The X-ray and radio morphology may be understood in terms of very thick shell and the bright central emission as due to reverse shock.

  18. Structural characterization and immunostimulating activity of a levan-type fructan from Curcuma kwangsiensis.

    Science.gov (United States)

    Dong, Cai-Xia; Zhang, Li-Jiao; Xu, Rong; Zhang, Gong; Zhou, Ying-Biao; Han, Xiao-Qiang; Zhang, Ying; Sun, Yuan-Xia

    2015-01-01

    A fructan designated as CKNP with apparent molecular weight of 5.3kD was isolated from the hot water extract of Curcuma kwangsiensis through a combination of ion-exchange chromatography on DEAE 650M and gel filtration on Superdex G-200. CKNP was characterized by chemical derivatization as well as HPLC, GC, and GC-MS technologies. Structural studies revealed that CKNP is composed predominately of fructose (96.8%) and a small amount of glucose (3.2%) with a degree of polymerization (DP) of 30-31. It was deduced to be a levan-type fructan containing a backbone composed of (2→6)-linked β-d-Fruf residues and single β-d-Fruf residues as side chains branched at the O-1 position along the backbone. Preliminary in vitro bioactive tests on RAW 264.7 murine macrophage cells revealed that the levan-type fructan from C. kwangsiensis shows significant immunostimulating activity based on its ability to stimulate macrophage proliferation and enhance phagocytosis. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Structural myocardial involvement in adult patients with type 1 myotonic dystrophy

    Directory of Open Access Journals (Sweden)

    Upinder K. Dhand

    2013-03-01

    Full Text Available Myotonic dystrophy type 1 (DM1 is the commonest muscular dystrophy in adults, affecting multiple organs in addition to skeletal muscles. Cardiac conduction system abnormalities are well recognized as an important component of DM1 phenotype; however, primary structural myocardial abnormalities, which may predispose these patients to congestive heart failure, are not as well characterized. We reviewed the retrospective analysis of the clinical and echocardiographic findings in adult patients with DM1. Among 27 patients (16 male; age 19-61 years with DM1, the echocardiogram (ECHO was abnormal in 10 (37% including one of 6 patients (16% with congenital myotonic dystrophy. Reduced left ventricular ejection fraction (LVEF ≤50% was noted in 5, diastolic dysfunction in 4, left atrial dilatation in 3, left ventricular hypertrophy in 2, apical hypokinesia in 1 and mitral valve prolapse in 3 patients. One patient had paradoxical septal movement in the setting of left bundle branch block. Echocardiographic abnormalities significantly correlated with older age; however, patients with systolic dysfunction on echocardiogram ranged in age from 27 to 52 years including 2 patients aged 27 and 34 years. We can conclude that echocardiographic abnormalities are frequent in adult patients with DM1. The incidence is similar in the classical and congenital type of DM1. Overall, echocardiographic abnormalities in DM1 correlate with increasing age; however, reduced LVEF is observed even at young age. Cardiac assessment and monitoring in adult patients with DM1 should include evaluation for primary myocardial involvement.

  20. Structure design and kinematics simulation of a novel arm-type single stereo parking lot

    Directory of Open Access Journals (Sweden)

    Dongliang Chu

    2015-09-01

    Full Text Available Space-saving, high-density stereo parking lots have gained considerable attention because of emerging limitations in ground and underground space. In this article, a novel arm-type single stereo parking lot is proposed to realize convenience and environmental friendliness. Many technical difficulties should be resolved before the safety performance of the stereo parking lot can be enhanced. Therefore, the structural characteristics, the load state and the motion situation should be analysed by numerical simulation to develop a reasonable design scheme. Finite element analysis was conducted on the steel tray platform, and kinematic analysis was performed on the end of novel arm-type single stereo parking lot. As a result, the position, velocity and acceleration curves as well as the maximum workspace were demonstrated by simulation in Pro/E. The simulation results demonstrate the correctness and accuracy of the stereo parking lot under motion mode feasible in residential areas and agency units and that the proposed parking lot can become popular in practice because of characteristics such as simplicity, convenience, easy development and promotion.

  1. Stokes shift and fine-structure splitting in CdSe/CdTe invert type-II ...

    Indian Academy of Sciences (India)

    Using the atomistic tight-binding (TB) theory and configuration interaction (CI) description, it is showed that the Stokes shift and fine-structure splitting (FSS) in semiconductor core/shell nanocrystals are predominantly affected by the shell thickness and band profiles. CdSe/CdTe invert type-II and CdTe/CdSe type-II core/shell ...

  2. Structure and Dynamics of RNA Repeat Expansions That Cause Huntington's Disease and Myotonic Dystrophy Type 1.

    Science.gov (United States)

    Chen, Jonathan L; VanEtten, Damian M; Fountain, Matthew A; Yildirim, Ilyas; Disney, Matthew D

    2017-07-11

    RNA repeat expansions cause a host of incurable, genetically defined diseases. The most common class of RNA repeats consists of trinucleotide repeats. These long, repeating transcripts fold into hairpins containing 1 × 1 internal loops that can mediate disease via a variety of mechanism(s) in which RNA is the central player. Two of these disorders are Huntington's disease and myotonic dystrophy type 1, which are caused by r(CAG) and r(CUG) repeats, respectively. We report the structures of two RNA constructs containing three copies of a r(CAG) [r(3×CAG)] or r(CUG) [r(3×CUG)] motif that were modeled with nuclear magnetic resonance spectroscopy and simulated annealing with restrained molecular dynamics. The 1 × 1 internal loops of r(3×CAG) are stabilized by one-hydrogen bond (cis Watson-Crick/Watson-Crick) AA pairs, while those of r(3×CUG) prefer one- or two-hydrogen bond (cis Watson-Crick/Watson-Crick) UU pairs. Assigned chemical shifts for the residues depended on the identity of neighbors or next nearest neighbors. Additional insights into the dynamics of these RNA constructs were gained by molecular dynamics simulations and a discrete path sampling method. Results indicate that the global structures of the RNA are A-form and that the loop regions are dynamic. The results will be useful for understanding the dynamic trajectory of these RNA repeats but also may aid in the development of therapeutics.

  3. Structure of the myotonic dystrophy type 2 RNA and designed small molecules that reduce toxicity.

    Science.gov (United States)

    Childs-Disney, Jessica L; Yildirim, Ilyas; Park, HaJeung; Lohman, Jeremy R; Guan, Lirui; Tran, Tuan; Sarkar, Partha; Schatz, George C; Disney, Matthew D

    2014-02-21

    Myotonic dystrophy type 2 (DM2) is an incurable neuromuscular disorder caused by a r(CCUG) expansion (r(CCUG)(exp)) that folds into an extended hairpin with periodically repeating 2×2 nucleotide internal loops (5'CCUG/3'GUCC). We designed multivalent compounds that improve DM2-associated defects using information about RNA-small molecule interactions. We also report the first crystal structure of r(CCUG) repeats refined to 2.35 Å. Structural analysis of the three 5'CCUG/3'GUCC repeat internal loops (L) reveals that the CU pairs in L1 are each stabilized by one hydrogen bond and a water-mediated hydrogen bond, while CU pairs in L2 and L3 are stabilized by two hydrogen bonds. Molecular dynamics (MD) simulations reveal that the CU pairs are dynamic and stabilized by Na(+) and water molecules. MD simulations of the binding of the small molecule to r(CCUG) repeats reveal that the lowest free energy binding mode occurs via the major groove, in which one C residue is unstacked and the cross-strand nucleotides are displaced. Moreover, we modeled the binding of our dimeric compound to two 5'CCUG/3'GUCC motifs, which shows that the scaffold on which the RNA-binding modules are displayed provides an optimal distance to span two adjacent loops.

  4. On the modular structure of the genus-one Type II superstring low energy expansion

    Energy Technology Data Exchange (ETDEWEB)

    D’Hoker, Eric [Department of Physics and Astronomy,University of California, Los Angeles, CA 90095 (United States); Green, Michael B. [Department of Applied Mathematics and Theoretical Physics,Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Vanhove, Pierre [Institut des Hautes Études Scientifiques, Le Bois-Marie, 35 route de Chartres,F-91440 Bures-sur-Yvette (France); Institut de physique théorique, Université Paris Saclay, CEA, CNRS,F-91191 Gif-sur-Yvette (France)

    2015-08-11

    The analytic contribution to the low energy expansion of Type II string amplitudes at genus-one is a power series in space-time derivatives with coefficients that are determined by integrals of modular functions over the complex structure modulus of the world-sheet torus. These modular functions are associated with world-sheet vacuum Feynman diagrams and given by multiple sums over the discrete momenta on the torus. In this paper we exhibit exact differential and algebraic relations for a certain infinite class of such modular functions by showing that they satisfy Laplace eigenvalue equations with inhomogeneous terms that are polynomial in non-holomorphic Eisenstein series. Furthermore, we argue that the set of modular functions that contribute to the coefficients of interactions up to order D{sup 10}R{sup 4} are linear sums of functions in this class and quadratic polynomials in Eisenstein series and odd Riemann zeta values. Integration over the complex structure results in coefficients of the low energy expansion that are rational numbers multiplying monomials in odd Riemann zeta values.

  5. On the modular structure of the genus-one Type II superstring low energy expansion

    Science.gov (United States)

    D'Hoker, Eric; Green, Michael B.; Vanhove, Pierre

    2015-08-01

    The analytic contribution to the low energy expansion of Type II string amplitudes at genus-one is a power series in space-time derivatives with coefficients that are determined by integrals of modular functions over the complex structure modulus of the world-sheet torus. These modular functions are associated with world-sheet vacuum Feynman diagrams and given by multiple sums over the discrete momenta on the torus. In this paper we exhibit exact differential and algebraic relations for a certain infinite class of such modular functions by showing that they satisfy Laplace eigenvalue equations with inhomogeneous terms that are polynomial in non-holomorphic Eisenstein series. Furthermore, we argue that the set of modular functions that contribute to the coefficients of interactions up to order are linear sums of functions in this class and quadratic polynomials in Eisenstein series and odd Riemann zeta values. Integration over the complex structure results in coefficients of the low energy expansion that are rational numbers multiplying monomials in odd Riemann zeta values.

  6. Structural controls on Carlin-type gold mineralization in the gold bar district, Eureka County, Nevada

    Science.gov (United States)

    Yigit, O.; Nelson, E.P.; Hitzman, M.W.; Hofstra, A.H.

    2003-01-01

    The Gold Bar district in the southern Roberts Mountains, 48 km northwest of Eureka, Nevada, contains one main deposit (Gold Bar), five satellite deposits, and other resources. Approximately 0.5 Moz of gold have been recovered from a resource of 1,639,000 oz of gold in Carlin-type gold deposits in lower plate, miogeoclinal carbonate rocks below the Roberts Mountains thrust. Host rocks are unit 2 of the Upper Member of the Devonian Denay Formation and the Bartine Member of the McColley Canyon Formation. Spatial and temporal relations between structures and gold mineralization indicate that both pre-Tertiary and Tertiary structures were important controls on gold mineralization. Gold mineralization occurs primarily along high-angle Tertiary normal faults, some of which are reactivated reverse faults of Paleozoic or Mesozoic age. Most deposits are localized at the intersection of northwest- and northeast-striking faults. Alteration includes decalcification, and to a lesser extent, silicification along high-angle faults. Jasperoid (pervasive silicification), which formed along most faults and in some strata-bound zones, accounts for a small portion of the ore in every deposit. In the Gold Canyon deposit, a high-grade jasperoid pipe formed along a Tertiary normal fault which was localized along a zone of overturned fault-propagation folds and thrust faults of Paleozoic or Mesozoic age.

  7. The Russian oil industry re-structuration: towards the emergence of western type enterprises?

    Energy Technology Data Exchange (ETDEWEB)

    Locatelli, C

    1999-01-01

    The Russian oil industry has undergone fundamental changes since the collapse of the Soviet Empire and its bureaucratic administrative structure, dominated by its various Branch Ministries. The monopoly in the Soviet oil industry has now been replaced by a number of ''oil companies'', some of which are very powerful, the best known of them being Lukoil. These ''joint stock companies'' are the product of a reform aimed essentially at implanting, out of all the numerous organisational arrangements developed in the West, the model of the vertically integrated private firm. Beyond the legal reforms in the Russian oil industry sector, however, the nature of the organisational model that has actually emerged in Russia begs several questions. Many entities, which are complex and highly diversified, are involved in this industry. There are, of course, the many private structures in which the banks sometimes carry a considerable amount of weight. There are also some vertically integrated organisations, but the degree of integration is variable and their method of centralization is based on a specific form of economic logic. It should not be considered, however, that these actors are similar to capitalist-type private enterprises, whose behaviour is regulated by the demands of international competition. Reform of property rights has not been sufficient to create true private enterprise in Russia. (author)

  8. Crystal structure of the pilotin from the enterohemorrhagic Escherichia coli type II secretion system

    Science.gov (United States)

    Korotkov, Konstantin V.; Hol, Wim G. J.

    2013-01-01

    Bacteria contain several sophisticated macromolecular machineries responsible for translocating proteins across the cell envelope. One prominent example is the type II secretion system (T2SS), which contains a large outer membrane channel, called the secretin. These gated channels require specialized proteins, so-called pilotins, to reach and assemble in the outer membrane. Here we report the crystal structure of the pilotin GspS from the T2SS of enterohemorrhagic Escherichia coli (EHEC), an important pathogen that can cause severe disease in cases of food poisoning. In this four-helix protein, the straight helix α2, the curved helix α3 and the bent helix α4 surround the central N-terminal helix α1. The helices of GspS create a prominent groove, mainly formed by side chains of helices α1, α2 and α3. In the EHEC GspS structure this groove is occupied by extra electron density which is reminiscent of an α-helix and corresponds well with a binding site observed in a homologous pilotin. The residues forming the groove are well conserved among homologs, pointing to a key role of this groove in this class of T2SS pilotins. At the same time, T2SS pilotins in different species can be entirely different in structure, and the pilotins for secretins in non-T2SS machineries have yet again unrelated folds, despite a common function. It is striking that a common complex function, such as targeting and assembling an outer membrane multimeric channel, can be performed by proteins with entirely different folds. PMID:23458689

  9. Structure and immunogenicity of the rough-type lipopolysaccharide from the periodontal pathogen Tannerella forsythia.

    Science.gov (United States)

    Posch, Gerald; Andrukhov, Oleh; Vinogradov, Evgeny; Lindner, Buko; Messner, Paul; Holst, Otto; Schäffer, Christina

    2013-06-01

    Tannerella forsythia is a Gram-negative anaerobic organism that inhabits subgingival plaque biofilms and is covered with a so far unique surface layer composed of two glycoproteins. It belongs to the so-called "red complex" of bacteria comprising species that are associated with periodontal disease. While the surface layer glycoprotein glycan structure had been elucidated recently and found to be a virulence factor, no structural data on the lipopolysaccharide (LPS) of this organism were available. In this study, the T. forsythia LPS structure was partially elucidated by a combined mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR) approach and initial experiments to characterize its immunostimulatory potential were performed. The T. forsythia LPS is a complex, rough-type LPS with a core region composed of one 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) residue, three mannose residues, and two glucosamine residues. MS analyses of O-deacylated LPS proved that, in addition, one phosphoethanolamine residue and most likely one galactose-phosphate residue were present, however, their positions could not be identified. Stimulation of human macrophages with T. forsythia LPS resulted in the production of the proinflammatory cytokines interleukin-1 (IL-1), IL-6, and tumor necrosis factor alpha in a dose-dependent manner. The response to T. forsythia LPS was observed only upon stimulation in the presence of fetal calf serum (FCS), whereas no cytokine production was observed in the absence of FCS. This finding suggests that the presence of certain additional cofactors is crucial for the immune response induced by T. forsythia LPS.

  10. Structure, process, and outcomes of care in a telemonitoring program for patients with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Nocella JM

    2016-03-01

    Full Text Available Jill M Nocella,1 Victoria Vaughan Dickson,2 Charles M Cleland,2 Gail D’Eramo Melkus2 1Department of Nursing, William Paterson University, Wayne, NJ, 2College of Nursing, New York University, New York, NY, USA Background: Using Donabedian's structure-process-outcomes (SPO framework, this descriptive, exploratory study examined the structure of a telemonitoring program in a population of patients with type 2 diabetes (T2D, the process of nurse–patient telephonic interactions, and patients’ clinical outcomes. Methods: Secondary data analysis was conducted using data from 581 patients who participated in a home telemonitoring program for 12 months. Three point-biserial and six Pearson correlations were estimated to determine how patient demographics related to clinical characteristics. Mixed model regressions were conducted predicting hemoglobin A1c (HbA1c, systolic blood pressure (SBP, and diastolic blood pressure (DBP levels at 6, 9, and 12 months based on the frequency of contact in the earlier 3 months. Analysis of variances were conducted to assess if the frequency of contact was significantly different by change in HbA1c levels from 3 to 6, 6 to 9, and 9 to 12 months. Results: Significant negative correlations were found between age and HbA1c (r=–0.10, P=0.015 and DBP (r=–0.16, P<0.001, a significant positive correlation was found between age and SBP (r=0.15, P=0.001. A significant correlation was found between sex and DBP (rpb=–0.11, P=0.015; female participants had lower DBP levels than males. Frequency of contact was not related to the change in clinical outcomes. However, the frequency of contact for the time period 3 to 6 months was associated with change in HbA1c for the 6- to 9- month period and frequency of contact during the 6- to 9- month period was associated with change in HbA1c from 9 to 12 months. Conclusion: Examination of the SPO measures in the telemonitoring environment assisted in understanding the effectiveness

  11. Structural characterization of mono-ruthenium substituted Keggin-type silicotungstates.

    Science.gov (United States)

    Sadakane, Masahiro; Tsukuma, Daisuke; Dickman, Michael H; Bassil, Bassem; Kortz, Ulrich; Higashijima, Michio; Ueda, Wataru

    2006-09-21

    We have synthesized the mono-ruthenium substituted Keggin-type silicotungstate [SiW(11)O(39)Ru(III)(H(2)O)](5-) (1a) by reaction of the mono-lacunary silicotungstate precursor [SiW(11)O(39)](8-) with Ru(acac)(3) under hydrothermal conditions and isolated as the caesium salt Cs(5)[SiW(11)O(39)Ru(III)(H(2)O)] (1). The DMSO-coordinated complex [SiW(11)O(39)Ru(III)(DMSO)](5-) (2a) was prepared by reaction of 1a with DMSO in aqueous solution at 353 K and isolated as the caesium-potassium mixed salt Cs(4.9)K(0.1)[SiW(11)O(39)Ru(III)(DMSO)] (2). Both compounds 1 and 2 were characterized by single-crystal X-ray structure analysis, powder X-ray structure analysis, UV-Vis spectroscopy, cyclic voltammetry, IR-spectroscopy and elemental analysis. 1 crystallized in the tetragonal space group P4(2)/ncm with a = 20.9299(4), c = 10.3603(4) Angstrom, Z = 4. The ruthenium atom in the Keggin unit could not be distinguished from the tungsten due to disorder. The structural analysis of 2 (monoclinic, P2(1)/c, a = 13.5850(4), b = 20.2764(7), c = 18.1326(4) Angstrom, beta = 90.8730(10) degrees , Z = 4) successfully revealed that the incorporated ruthenium atom is coordinated by DMSO through a Ru-S bond. Polyanion 2a represents the first mono-substituted Keggin ion in which the ruthenium center is not crystallographically disordered. UV-Vis spectroscopy combined with controlled potential electrolysis confirmed that the incorporated rutheniums in 1 and 2 have a valence state of +3. The IR spectra of both 1 and 2 were very similar. All these data indicate that 1 synthesized by reaction of the mono-lacunary silicotungstate K(8)[SiW(11)O(39)] with Ru(acac)(3) under hydrothermal conditions is truly the mono-ruthenium substituted Keggin-type silicotungstate.

  12. NES consensus redefined by structures of PKI-type and Rev-type nuclear export signals bound to CRM1.

    Science.gov (United States)

    Güttler, Thomas; Madl, Tobias; Neumann, Piotr; Deichsel, Danilo; Corsini, Lorenzo; Monecke, Thomas; Ficner, Ralf; Sattler, Michael; Görlich, Dirk

    2010-11-01

    Classic nuclear export signals (NESs) confer CRM1-dependent nuclear export. Here we present crystal structures of the RanGTP-CRM1 complex alone and bound to the prototypic PKI or HIV-1 Rev NESs. These NESs differ markedly in the spacing of their key hydrophobic (Φ) residues, yet CRM1 recognizes them with the same rigid set of five Φ pockets. The different Φ spacings are compensated for by different conformations of the bound NESs: in the case of PKI, an α-helical conformation, and in the case of Rev, an extended conformation with a critical proline docking into a Φ pocket. NMR analyses of CRM1-bound and CRM1-free PKI NES suggest that CRM1 selects NES conformers that pre-exist in solution. Our data lead to a new structure-based NES consensus, and explain why NESs differ in their affinities for CRM1 and why supraphysiological NESs bind the exportin so tightly.

  13. Monazite-type ceramics for conditioning of minor actinides. Structural characterization and properties

    Energy Technology Data Exchange (ETDEWEB)

    Babelot, Carole

    2013-07-01

    . Structural and morphological characteristics (using X-ray diffraction (XRD) and scanning electron microscope (SEM)) combined with physical and thermal properties of samples (using thermogravimetry, differential scanning calorimetry (TG-DSC) and dilatometry) are realized in order to study the behavior of monazite-type powder and pellets. The access to short-range-order spectroscopy (time resolved laser fluorescence spectroscopy (TRLFS) and extended X-ray absorption fine structure (EXAFS)) permits to understand the structure of ceramic waste forms at the molecular level. La-monazite matrices being doped with Eu (III) (as a non-radioactive chemical homologue for Am (III)) and Cm (III), TRLFS is used to explore the local structural environment of Eu and Cm within the monazite crystal structure. Eu (III) and Cm (III) are substituted on the La site of LaPO{sub 4}. The single site of Cm (III) is found in four slightly different environments which is assumed to be due to a difference in the four La sites within a LaPO4 unit cell. Structural parameters of the Eu (III) species were also analyzed by EXAFS. The nearest neighbors of Eu (III) are modeled as 9.5 oxygen atoms (N{sub O1} = 4 at r(EuO1) = 2.37 Aa, N{sub O2} = 4 at r(Eu-O2) = 2.53 Aa, and N{sub O3} = 1.5 at r(Eu-O3) = 2.83 Aa). An essential parameter that describes the stability of the host phases is their dissolution rate obtained under conditions of relevance for final repositories. In this context, a set-up is developed and tested on crushed pellets. Normalized weight losses of lanthanumphosphates and europium-doped lanthanum-phosphates, measured in acidic media at 90 C, are interpreted and compared against the previous findings from the literature. The normalized dissolution rate for La and Eu within (La, Eu)PO{sub 4} is between 1.10{sup -5} and 1.10{sup -4} g.m{sup -2}.d{sup -1}, whereas the rate of Na, Cs and Sr in phosphate glass at room temperature in deionized water is about 1.10{sup -2} g.m{sup -2}.d{sup -1}. Another

  14. Four types of interference competition and their impacts on the ecology and evolution of size-structured populations and communities

    DEFF Research Database (Denmark)

    Zhang, Lai; Andersen, Ken Haste; Dieckmann, Ulf

    2015-01-01

    We investigate how four types of interference competition - which alternatively affect foraging, metabolism, survival, and reproduction - impact the ecology and evolution of size-structured populations. Even though all four types of interference competition reduce population biomass, interference...... competition at intermediate intensity sometimes significantly increases the abundance of adult individuals and the population[U+05F3]s reproduction rate. We find that foraging and metabolic interference evolutionarily favor smaller maturation size when interference is weak and larger maturation size when...... together, our results show how the type and intensity of interference competition jointly affect coexistence patterns in structured population models...

  15. Systematic determination of replication activity type highlights interconnections between replication, chromatin structure and nuclear localization.

    Science.gov (United States)

    Farkash-Amar, Shlomit; David, Yaara; Polten, Andreas; Hezroni, Hadas; Eldar, Yonina C; Meshorer, Eran; Yakhini, Zohar; Simon, Itamar

    2012-01-01

    DNA replication is a highly regulated process, with each genomic locus replicating at a distinct time of replication (ToR). Advances in ToR measurement technology enabled several genome-wide profiling studies that revealed tight associations between ToR and general genomic features and a remarkable ToR conservation in mammals. Genome wide studies further showed that at the hundreds kb-to-megabase scale the genome can be divided into constant ToR regions (CTRs) in which the replication process propagates at a faster pace due to the activation of multiple origins and temporal transition regions (TTRs) in which the replication process propagates at a slower pace. We developed a computational tool that assigns a ToR to every measured locus and determines its replication activity type (CTR versus TTR). Our algorithm, ARTO (Analysis of Replication Timing and Organization), uses signal processing methods to fit a constant piece-wise linear curve to the measured raw data. We tested our algorithm and provide performance and usability results. A Matlab implementation of ARTO is available at http://bioinfo.cs.technion.ac.il/people/zohar/ARTO/. Applying our algorithm to ToR data measured in multiple mouse and human samples allowed precise genome-wide ToR determination and replication activity type characterization. Analysis of the results highlighted the plasticity of the replication program. For example, we observed significant ToR differences in 10-25% of the genome when comparing different tissue types. Our analyses also provide evidence for activity type differences in up to 30% of the probes. Integration of the ToR data with multiple aspects of chromosome organization characteristics suggests that ToR plays a role in shaping the regional chromatin structure. Namely, repressive chromatin marks, are associated with late ToR both in TTRs and CTRs. Finally, characterization of the differences between TTRs and CTRs, with matching ToR, revealed that TTRs are associated with

  16. Systematic determination of replication activity type highlights interconnections between replication, chromatin structure and nuclear localization.

    Directory of Open Access Journals (Sweden)

    Shlomit Farkash-Amar

    Full Text Available DNA replication is a highly regulated process, with each genomic locus replicating at a distinct time of replication (ToR. Advances in ToR measurement technology enabled several genome-wide profiling studies that revealed tight associations between ToR and general genomic features and a remarkable ToR conservation in mammals. Genome wide studies further showed that at the hundreds kb-to-megabase scale the genome can be divided into constant ToR regions (CTRs in which the replication process propagates at a faster pace due to the activation of multiple origins and temporal transition regions (TTRs in which the replication process propagates at a slower pace. We developed a computational tool that assigns a ToR to every measured locus and determines its replication activity type (CTR versus TTR. Our algorithm, ARTO (Analysis of Replication Timing and Organization, uses signal processing methods to fit a constant piece-wise linear curve to the measured raw data. We tested our algorithm and provide performance and usability results. A Matlab implementation of ARTO is available at http://bioinfo.cs.technion.ac.il/people/zohar/ARTO/. Applying our algorithm to ToR data measured in multiple mouse and human samples allowed precise genome-wide ToR determination and replication activity type characterization. Analysis of the results highlighted the plasticity of the replication program. For example, we observed significant ToR differences in 10-25% of the genome when comparing different tissue types. Our analyses also provide evidence for activity type differences in up to 30% of the probes. Integration of the ToR data with multiple aspects of chromosome organization characteristics suggests that ToR plays a role in shaping the regional chromatin structure. Namely, repressive chromatin marks, are associated with late ToR both in TTRs and CTRs. Finally, characterization of the differences between TTRs and CTRs, with matching ToR, revealed that TTRs are

  17. Structural, electronic and magnetic properties of chevron-type graphene, BN and BC{sub 2}N nanoribbons

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, T.; Azevedo, S. [Departamento de Física/CCEN, Universidade Federal da Paraíba, Caixa Postal 5008, 58051-900 João Pessoa, PB (Brazil); Kaschny, J.R. [Instituto Federal da Bahia-Campus Vitória da Conquista, Caixa Postal 3150, 45075-265 Vitória da Conquista, BA (Brazil)

    2017-04-15

    Graphene nanoribbons are predicted to be essential components in future nanoelectronics. The size, edge type, arrangement of atoms and width of nanoribbons drastically change their properties. Boronnitrogencarbon nanoribbons properties are not fully understood so far. In the present contribution it was investigated the structural, electronic and magnetic properties of chevron-type carbon, boron nitride and BC{sub 2}N nanoribbons, using first-principles calculations. The results indicate that the structural stability is closely related to the discrepancies in the bond lengths, which can induce structural deformations and stress. Such nanoribbons present a wide range of electronic behaviors, depending on their composition and particularities of the atomic arrangement. A net magnetic moment is found for structures that present carbon atoms at the nanoribbon borders. Nevertheless, the calculated magnetic moment depends on the peculiarities of the symmetric arrangement of atoms and imbalance of carbon atoms between different sublattices. It was found that all structures which have a significant energy gap do not present magnetic moment, and vice-versa. Such result indicates the strong correlation between the electronic and magnetic properties of the chevron-type nanoribbons. - Highlights: • Small discrepancies between distinct bond lengths can influence the formation energy of the BC{sub 2}N nanoribbons. • The electronic behavior of the BC{sub 2}N chevron-type nanoribbons depends on the atomic arrangement and structural symmetries. • There is a strong correlation between the electronic and magnetic properties for the BC{sub 2}N structures.

  18. Structural and magnetic properties of Ca-substituted barium W-type hexagonal hexaferrites

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Kai [Engineering Technology Research Center of Magnetic Materials, Anhui Province, School of Physics & Materials Science, Anhui University, Hefei 230601 (China); Department of Mathmatic and Physics, Anhui Jianzhu University, Hefei 230601 (China); Liu, Xiansong, E-mail: xiansongliu@ahu.edu.cn [Engineering Technology Research Center of Magnetic Materials, Anhui Province, School of Physics & Materials Science, Anhui University, Hefei 230601 (China); Feng, Shuangjiu; Zhang, Zhanjun [Engineering Technology Research Center of Magnetic Materials, Anhui Province, School of Physics & Materials Science, Anhui University, Hefei 230601 (China); Yu, Jiangying [Department of Mathmatic and Physics, Anhui Jianzhu University, Hefei 230601 (China); Niu, Xiaofei; Lv, Farui; Huang, Xing [Engineering Technology Research Center of Magnetic Materials, Anhui Province, School of Physics & Materials Science, Anhui University, Hefei 230601 (China)

    2015-04-01

    A series of W-type hexagonal ferrites with the composition Ba{sub 1−x}Ca{sub x}Co{sub 2}Fe{sub 16}O{sub 27} (x=0, 0.1, 0.3, 0.4 and 0.5) were synthesized using a sol–gel method. The effects of doping on structural and magnetic properties are studied by X-ray diffraction, thermal analyzer, scanning electron microscopy, vibrating sample magnetometer and vector network analyzer, respectively. The X-ray diffraction analysis shows that the samples belong to the W-type hexagonal ferrite. The lattice constants a and c decreases as Ca contents increases. The grains exhibit well defined hexagonal shape. The saturation magnetization and the intrinsic coercive force increases with the increase of the Ca substitution amount. The real part of complex permittivity (ε′) and imaginary part (ε″) increase with more addition of Ca{sup 2+} amount. The imaginary part of complex permittivity (μ′) increases and the real part (μ′′) goes down after Ca{sup 2+} is doped. Furthermore, the Ca{sup 2+} ions doped in the ferrite improved microwave absorbency. - Highlights: • Various Ba{sub 1−x}Ca{sub x}Co{sub 2}Fe{sub 16}O{sub 27} (x=0, 0.1, 0.3, 0.4 and 0.5) ferrites are W-type phase with a space group of p63/mmc and no any extra peak were observed in the powder XRD patterns.The lattice constants a and c decrease as Ca contents increases. • Three weight loss steps corresponding to one sharp exothermic peak have been observed in the TG curve. • The shape and diameters of most the grains remains almost independent of Ca{sup 2+} substitution by scanning electron microscopy. • The saturation magnetization and the intrinsic coercive force increases with the increase of the Ca substitution amount. • The real part of complex permittivity (ε′) and imaginary part (ε″) increase with more addition of Ca{sup 2+} amount. The imaginary part of complex permittivity (μ′) increases and the real part (μ′′) goes down after Ca{sup 2+} is doped. Furthermore, the Ca{sup 2

  19. Dominant Tree Species and Soil Type Affect the Fungal Community Structure in a Boreal Peatland Forest.

    Science.gov (United States)

    Sun, Hui; Terhonen, Eeva; Kovalchuk, Andriy; Tuovila, Hanna; Chen, Hongxin; Oghenekaro, Abbot O; Heinonsalo, Jussi; Kohler, Annegret; Kasanen, Risto; Vasander, Harri; Asiegbu, Fred O

    2016-05-01

    Boreal peatlands play a crucial role in global carbon cycling, acting as an important carbon reservoir. However, little information is available on how peatland microbial communities are influenced by natural variability or human-induced disturbances. In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal transcribed spacer (ITS) region. We have also compared the fungal communities during the primary colonization of wood with those of the surrounding soils. A permutational multivariate analysis of variance (PERMANOVA) confirmed that the community composition significantly differed between soil types (Pstructure (Psoil nutrients (Ca [P= 0.002], Fe [P= 0.003], and P [P= 0.003]) within the site was an important factor in the fungal community composition. The species richness in wood was significantly lower than in the corresponding soil (P< 0.004). The results of the molecular identification were supplemented by fruiting body surveys. Seven of the genera of Agaricomycotina identified in our surveys were among the top 20 genera observed in pyrosequencing data. Our study is the first, to our knowledge, fungal high-throughput next-generation sequencing study performed on peatlands; it further provides a baseline for the investigation of the dynamics of the fungal community in the boreal peatlands. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  20. Structural characterization of a novel Chlamydia pneumoniae type III secretion-associated protein, Cpn0803.

    Directory of Open Access Journals (Sweden)

    Chris B Stone

    Full Text Available Type III secretion (T3S is an essential virulence factor used by gram-negative pathogenic bacteria to deliver effector proteins into the host cell to establish and maintain an intracellular infection. Chlamydia is known to use T3S to facilitate invasion of host cells but many proteins in the system remain uncharacterized. The C. trachomatis protein CT584 has previously been implicated in T3S. Thus, we analyzed the CT584 ortholog in C. pneumoniae (Cpn0803 and found that it associates with known T3S proteins including the needle-filament protein (CdsF, the ATPase (CdsN, and the C-ring protein (CdsQ. Using membrane lipid strips, Cpn0803 interacted with phosphatidic acid and phosphatidylinositol, suggesting that Cpn0803 may associate with host cells. Crystallographic analysis revealed a unique structure of Cpn0803 with a hydrophobic pocket buried within the dimerization interface that may be important for binding small molecules. Also, the binding domains on Cpn0803 for CdsN, CdsQ, and CdsF were identified using Pepscan epitope mapping. Collectively, these data suggest that Cpn0803 plays a role in T3S.

  1. Structural characterization of a novel Chlamydia pneumoniae type III secretion-associated protein, Cpn0803.

    Science.gov (United States)

    Stone, Chris B; Sugiman-Marangos, Seiji; Bulir, David C; Clayden, Rob C; Leighton, Tiffany L; Slootstra, Jerry W; Junop, Murray S; Mahony, James B

    2012-01-01

    Type III secretion (T3S) is an essential virulence factor used by gram-negative pathogenic bacteria to deliver effector proteins into the host cell to establish and maintain an intracellular infection. Chlamydia is known to use T3S to facilitate invasion of host cells but many proteins in the system remain uncharacterized. The C. trachomatis protein CT584 has previously been implicated in T3S. Thus, we analyzed the CT584 ortholog in C. pneumoniae (Cpn0803) and found that it associates with known T3S proteins including the needle-filament protein (CdsF), the ATPase (CdsN), and the C-ring protein (CdsQ). Using membrane lipid strips, Cpn0803 interacted with phosphatidic acid and phosphatidylinositol, suggesting that Cpn0803 may associate with host cells. Crystallographic analysis revealed a unique structure of Cpn0803 with a hydrophobic pocket buried within the dimerization interface that may be important for binding small molecules. Also, the binding domains on Cpn0803 for CdsN, CdsQ, and CdsF were identified using Pepscan epitope mapping. Collectively, these data suggest that Cpn0803 plays a role in T3S.

  2. The structural and optical properties of type III human collagen biosynthetic corneal substitutes

    Science.gov (United States)

    Hayes, Sally; Lewis, Phillip; Islam, M. Mirazul; Doutch, James; Sorensen, Thomas; White, Tomas; Griffith, May; Meek, Keith M.

    2015-01-01

    The structural and optical properties of clinically biocompatible, cell-free hydrogels comprised of synthetically cross-linked and moulded recombinant human collagen type III (RHCIII) with and without the incorporation of 2-methacryloyloxyethyl phosphorylcholine (MPC) were assessed using transmission electron microscopy (TEM), X-ray scattering, spectroscopy and refractometry. These findings were examined alongside similarly obtained data from 21 human donor corneas. TEM demonstrated the presence of loosely bundled aggregates of fine collagen filaments within both RHCIII and RHCIII-MPC implants, which X-ray scattering showed to lack D-banding and be preferentially aligned in a uniaxial orientation throughout. This arrangement differs from the predominantly biaxial alignment of collagen fibrils that exists in the human cornea. By virtue of their high water content (90%), very fine collagen filaments (2–9 nm) and lack of cells, the collagen hydrogels were found to transmit almost all incident light in the visible spectrum. They also transmitted a large proportion of UV light compared to the cornea which acts as an effective UV filter. Patients implanted with these hydrogels should be cautious about UV exposure prior to regrowth of the epithelium and in-growth of corneal cells into the implants. PMID:26159106

  3. Tangshen Formula Attenuates Colonic Structure Remodeling in Type 2 Diabetic Rats

    DEFF Research Database (Denmark)

    Chen, Pengmin; Zhao, Jingbo; Zhang, Haojun

    2017-01-01

    Aim. This study investigated the effect and mechanism of the Chinese herbal medicine Tangshen Formula (TSF) on GI structure remodeling in the rat model of diabetes. Methods. Type 2 diabetic rats were used. Wet weight per unit length, layer thicknesses, levels of collagens I and III, nuclear factor...... kappa B (NF-κB), interferon-γ (IFN-γ), interleukin-6 (IL-6), transforming growth factor-β1 (TGF-β1), and Smad2/3 expression in the rat colon were measured. Results. Compared with the control group animals, wet weight and layer thicknesses of the colon increased, and expressions of collagens I and III......, NF-κB, IFN-γ, IL-6, TGF-β1, and Smad2/3 increased significantly in the diabetic animals. TSF inhibited increase in colonic wet weight and layer thicknesses, downregulated expressions of collagens I and III in the mucosal layer, and downregulated expressions of NF-κB, IFN-γ, IL-6, TGF-β1, and Smad2...

  4. [Lasers in dentistry. Part A--Development, characteristics, structure, principles of operation and types of lasers].

    Science.gov (United States)

    Stabholz, A; Stabholz, A; Leopold, Y; Rosenberg, Y; Moshonov, J

    2001-04-01

    Laser technology is developing very quickly. New Lasers with a wide range of characteristics are available today and are being used in the various fields of dentistry. The search for new devices and technologies for dental procedures was always challenging and in the last two decades much experience and knowledge has been gained. The purpose of this series of articles published in the journal of the Israel Dental Association in three parts is to present the Israeli dentist a comprehensive and contemporary overview which will assist him in understanding the potential of the use of laser technology for clinical applications in dentistry. The first part will describe the history and development of lasers in dentistry, the characteristics and structure of lasers as well as their principles of operation. A description of the different types of lasers used today in dentistry will be presented in the first part. The second part will describe the interaction of lasers with biological tissues and their effect on the soft and hard tissues of the oral cavity as well as on the dental pulp. Laser safety in the dental practice will also be discussed. The third part will focus on clinical applications of Lasers in Dentistry: pits and fissures sealing, dentin desensitization, cavity preparations, composite curing, surgical procedures and tooth whitening. Current status of using lasers in periodontics, endodontics and dental implantology will be discussed and possible future clinical applications of lasers in dentistry will be presented.

  5. Development of layered anode structures supported over Apatite-type Solid Electrolytes

    Directory of Open Access Journals (Sweden)

    Pandis P.

    2016-01-01

    Full Text Available Apatite-type lanthanum silicates (ATLS materials have attracted interest in recent literature as solid electrolytes for SOFCs. The fabrication of an ATLS based fuel cell with the state-of-art electrodes (NiO/YSZ as anode and LSCF or LSM as cathode can show degradation after long operation hours due to Si diffusion mainly towards the anode. In this work, we report a “layer-by-layer anodic electrodes” fabrication by means of spin coating and physical spraying. The overall aim of this work is the successful fabrication of such a layered structure including suitable blocking layers towards the inhibition of Si interdiffusion from the apatite electrolyte to the anode. The results showed that the deposition of 3 layers of LFSO/GDC (3μm, NiO/GDC (4μm and the final NiO/YSZ anode layer provided a stable half-cell, with no solid state reaction occurring among the electrodes and no Si diffusion observed towards the anode after thermal treatment at 800°C for 120h.

  6. Dominant Tree Species and Soil Type Affect the Fungal Community Structure in a Boreal Peatland Forest

    Science.gov (United States)

    Terhonen, Eeva; Kovalchuk, Andriy; Tuovila, Hanna; Chen, Hongxin; Oghenekaro, Abbot O.; Heinonsalo, Jussi; Kohler, Annegret; Kasanen, Risto; Vasander, Harri; Asiegbu, Fred O.

    2016-01-01

    Boreal peatlands play a crucial role in global carbon cycling, acting as an important carbon reservoir. However, little information is available on how peatland microbial communities are influenced by natural variability or human-induced disturbances. In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal transcribed spacer (ITS) region. We have also compared the fungal communities during the primary colonization of wood with those of the surrounding soils. A permutational multivariate analysis of variance (PERMANOVA) confirmed that the community composition significantly differed between soil types (P soil nutrients (Ca [P = 0.002], Fe [P = 0.003], and P [P = 0.003]) within the site was an important factor in the fungal community composition. The species richness in wood was significantly lower than in the corresponding soil (P body surveys. Seven of the genera of Agaricomycotina identified in our surveys were among the top 20 genera observed in pyrosequencing data. Our study is the first, to our knowledge, fungal high-throughput next-generation sequencing study performed on peatlands; it further provides a baseline for the investigation of the dynamics of the fungal community in the boreal peatlands. PMID:26896139

  7. The Interplay of Implicit Causality, Structural Heuristics, and Anaphor Type in Ambiguous Pronoun Resolution.

    Science.gov (United States)

    Järvikivi, Juhani; van Gompel, Roger P G; Hyönä, Jukka

    2017-06-01

    Two visual-world eye-tracking experiments investigating pronoun resolution in Finnish examined the time course of implicit causality information relative to both grammatical role and order-of-mention information. Experiment 1 showed an effect of implicit causality that appeared at the same time as the first-mention preference. Furthermore, when we counterbalanced the semantic roles of the verbs, we found no effect of grammatical role, suggesting the standard observed subject preference has a large semantic component. Experiment 2 showed that both the personal pronoun hän and the demonstrative tämä preferred the antecedent consistent with the implicit causality bias; tämä was not interpreted as referring to the semantically non-prominent entity. In contrast, structural prominence affected hän and tämä differently: we found a first-mention preference for hän, but a second-mention preference for tämä. The results suggest that semantic implicit causality information has an immediate effect on pronoun resolution and its use is not delayed relative to order-of-mention information. Furthermore, they show that order-of-mention differentially affects different types of anaphoric expressions, but semantic information has the same effect.

  8. The structural and optical properties of type III human collagen biosynthetic corneal substitutes.

    Science.gov (United States)

    Hayes, Sally; Lewis, Phillip; Islam, M Mirazul; Doutch, James; Sorensen, Thomas; White, Tomas; Griffith, May; Meek, Keith M

    2015-10-01

    The structural and optical properties of clinically biocompatible, cell-free hydrogels comprised of synthetically cross-linked and moulded recombinant human collagen type III (RHCIII) with and without the incorporation of 2-methacryloyloxyethyl phosphorylcholine (MPC) were assessed using transmission electron microscopy (TEM), X-ray scattering, spectroscopy and refractometry. These findings were examined alongside similarly obtained data from 21 human donor corneas. TEM demonstrated the presence of loosely bundled aggregates of fine collagen filaments within both RHCIII and RHCIII-MPC implants, which X-ray scattering showed to lack D-banding and be preferentially aligned in a uniaxial orientation throughout. This arrangement differs from the predominantly biaxial alignment of collagen fibrils that exists in the human cornea. By virtue of their high water content (90%), very fine collagen filaments (2-9 nm) and lack of cells, the collagen hydrogels were found to transmit almost all incident light in the visible spectrum. They also transmitted a large proportion of UV light compared to the cornea which acts as an effective UV filter. Patients implanted with these hydrogels should be cautious about UV exposure prior to regrowth of the epithelium and in-growth of corneal cells into the implants. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  9. Physical properties of new cerium palladium phosphide with C6Cr23-type structure

    Directory of Open Access Journals (Sweden)

    T. Abe

    2014-01-01

    Full Text Available We have found that a cerium palladium phosphide crystallizes into a C6Cr23-type structure with atomic disorder. Prepared polycrystalline samples show a homogeneity range in the ternary Ce–Pd–P phase diagram. The physical properties of the highest-quality sample of Ce2.4Pd20.7P5.9 were investigated by measuring the magnetization, electrical resistivity and specific heat. No pronounced phase transition was observed down to 0.5 K. The Kondo screening of localized 4f electrons in metallic Ce2.4Pd20.7P5.9 appears to be weaker than that in the isostructural compounds of Ce3Pd20Si6 and Ce3Pd20Ge6. By a comparative study of Ce2.4Pd20.7P5.9 and Ce3Pd20X6 (X = Si, Ge, the competition between the Kondo temperature and ordering temperatures including the quadrupolar ordering temperature is briefly discussed.

  10. Structure and function of invertebrate Kazal-type serine proteinase inhibitors.

    Science.gov (United States)

    Rimphanitchayakit, Vichien; Tassanakajon, Anchalee

    2010-04-01

    Proteinases and proteinase inhibitors are involved in several biological and physiological processes in all multicellular organisms. The proteinase inhibitors function as modulators for controlling the extent of deleterious proteinase activity. The Kazal-type proteinase inhibitors (KPIs) in family I1 are among the well-known families of proteinase inhibitors, widely found in mammals, avian and a variety of invertebrates. Like those classical KPIs, the invertebrate KPIs can be single or multiple domain proteins containing one or more Kazal inhibitory domains linked together by peptide spacers of variable length. All invertebrate Kazal domains of about 40-60 amino acids in length share a common structure which is dictated by six conserved cysteine residues forming three intra-domain disulfide cross-links despite the variability of amino acid sequences between the half-cystines. Invertebrate KPIs are strong inhibitors as shown by their extremely high association constant of 10(7)-10(13)M(-1). The inhibitory specificity of a Kazal domain varies widely with a different reactive P(1) amino acid. Different invertebrate KPI domains may arise from gene duplication but several KPI proteins can also be derived from alternative splicing. The invertebrate KPIs function as anticoagulants in blood-sucking animals such as leech, mosquitoes and ticks. Several KPIs are likely involved in protecting host from microbial proteinases while some from the parasitic protozoa help protecting the parasites from the host digestive proteinase enzymes. Silk moths produce KPIs to protect their cocoon from predators and microbial destruction.

  11. Finite Element Model for Thermal-Structural analysis of CLIC Lab Module type 0#2

    CERN Document Server

    Moilanen, Antti; Vamvakas, Alex; Vainola, Jukka Ilmari; Doebert, Steffen

    2017-01-01

    Temperature changes lead to unwanted thermo-mechanical deformations in the components of the Compact Linear Collider (CLIC) module. There are several sources and sinks of heat around the CLIC two-beam module. Heat is generated in the components that produce, transfer, and extract radio frequency (RF) power. Excess heat is removed from the components by cooling water as well as dissipated to air by convection from the outer surfaces of the components. The ambient temperature might also vary along the tunnel during the operation of CLIC. Due to tight assembling and alignment tolerances, it is necessary to minimize the thermo-mechanical deformations in the components. In this paper, the steps of thermal-structural Finite Element Analysis (FEA) of CLIC lab module type 0#2 are described from geometry model simplification to setting up the simulation. The description is accompanied by useful hints for CATIA and ANSYS users performing similar modelling tasks. A reliable computer simulation is important for studying ...

  12. Structure of Human M-type Phospholipase A2 Receptor Revealed by Cryo-Electron Microscopy.

    Science.gov (United States)

    Dong, Yue; Cao, Longxing; Tang, Hua; Shi, Xiangyi; He, Yongning

    2017-12-08

    M-type phospholipase A2 receptor (M-PLA2R) is a member of the mannose receptor family and known as the receptor of secretory phospholipase A2s. It has also been identified as the major autoantigen of idiopathic membranous nephropathy, one of the most common causes for nephrotic syndrome in adults. Here we determine the structure of human M-PLA2R ectodomain by cryo-electron microscopy. The results show that the ectodomain has high internal flexibility and forms a compact dual-ring-shaped conformation at acidic pH and adopts extended conformations at basic pH. The inter-domain interactions of human M-PLA2R are explored by the binding studies with individual domains, showing the mechanism of the conformational change. In addition, the biochemical data suggest that mouse M-PLA2R recognizes mouse secretory phospholipase A2-G1B only at physiological or basic pH, rather than at acidic pH. These results suggest that the pH-dependent conformational change might play important roles in the functional activities of M-PLA2R such as ligand binding and release, and may also be relevant to the immunogenicity in membranous nephropathy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Neutron scattering studies of domain structures in type-II superconductor niobium

    Energy Technology Data Exchange (ETDEWEB)

    Reimann, Tommy; Schulz, Michael [Heinz Maier-Leibnitz Zentrum (MLZ), TU Muenchen, Garching (Germany); Physikdepartment E21, TU Muenchen, Garching (Germany); Muehlbauer, Sebastian [Heinz Maier-Leibnitz Zentrum (MLZ), TU Muenchen, Garching (Germany); Gruenzweig, Christian [Paul-Scherrer-Institut, Villigen (Switzerland); Boeni, Peter [Physikdepartment E21, TU Muenchen, Garching (Germany)

    2014-07-01

    In the intermediate mixed state (IMS) of a type II superconductor (SC), the sample splits up into Meissner domains and Shubnikov domains which carry the vortex lattice (VL). A detailed investigation of these domain patterns offers the possibility to study general characteristics of domain nucleation and morphology as well as the physical properties of vortex-vortex and vortex-pinning interactions. In this talk we show that ultra small angle neutron scattering (USANS) can be used for the identification of VL properties. We have studied the VL domain morphology in a Nb single crystal disc that exhibit strong vortex pinning. USANS is sensitive to structures with sizes up to 20 microns and is therefore capable to probe IMS domains which is not possible with the commonly used small angle neutron scattering (SANS). Furthermore, USANS averages over the whole sample and hence probes the bulk of the material in contrast to magneto optical methods. Our investigation on the IMS of Nb reveals a preferred domain size with a strong dependence on magnetic field and sample thickness. Surprisingly, the average domain size is nearly independent of the temperature in a field cooled measurement giving some hint on the nature of field expulsion in the IMS of samples with significant pinning.

  14. Structure-activity relationship of a u-type antimicrobial microemulsion system.

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    Full Text Available The structure-activity relationship of a U-type antimicrobial microemulsion system containing glycerol monolaurate and ethanol at a 1∶1 mass ratio as oil phase and Tween 20 as surfactant were investigated along a water dilution line at a ratio of 80∶20 mass% surfactant/oil phase, based on a pseudo-ternary phase diagram. The differential scanning calorimetry results showed that in the region of up to 33% water, all water molecules are confined to the hydrophilic core of the reverse micelles, leading to the formation of w/o microemulsion. As the water content increases, the water gains mobility, and transforms into bicontinuous in the region of 33-39% water, and finally the microemulsion become o/w in the region of above 39% water. The microstructure characterization was confirmed by the dynamic light scattering measurements and freeze-fracture transmission electron microscope observation. The antimicrobial activity assay using kinetics of killing analysis demonstrated that the microemulsions in w/o regions exhibited relatively high antimicrobial activity against Escherichia coli and Staphylococcus aureus due to the antimicrobial oil phase as the continuous phase, while the antimicrobial activity started to decrease when the microemulsions entered the bicontinuous region, and decreased rapidly as the water content increased in the o/w region, as a result of the dilution of antimicrobial oil droplets in the aqueous continuous phase.

  15. Five types of polyurethane vascular grafts in dogs: the importance of structural design and material selection.

    Science.gov (United States)

    Xie, Xingyi; Eberhart, Andreas; Guidoin, Robert; Marois, Yves; Douville, Yvan; Zhang, Ze

    2010-01-01

    Five polyurethane vascular grafts with three different chemistries were investigated in terms of device function, healing characteristics and material stability in a canine abdominal aorta model for prescheduled periods of 1 and 6 months. Corvita-reinforced grafts, with walls made of poly(carbonate urethane) (PCU) filaments, displayed a relatively thin, uniform and partially endothelialized inner capsule with good tissue in-growth. The external polyester mesh separated from the underlying PCU wall due to the degradation of the melt adhesive between these two layers. Three types of Thoratec access graft exhibited a high degree of thrombus and little tissue in-growth, and were non-adhesive to both the inner and external capsules as the solid layer beneath their lumens completely blocked any transmural communication. The microporous poly(ether urethane urea) degraded extensively. Pulse-Tec grafts at one month also demonstrated non-adhesive properties because the external skin served as a barrier to tissue in-growth. At 6 months, its poly(ether urethane) wall displayed the most severe degradation, damaging graft structural integrity and causing significant tissue deposition in the degradation areas. This study shows the importance of multiple factors in vascular prosthesis design and demonstrates that collective and comprehensive thinking will be key in the future development of creative and novel approaches.

  16. Symbol nomenclature for representing glycan structures: Extension to cover different carbohydrate types.

    Science.gov (United States)

    Harvey, David J; Merry, Anthony H; Royle, Louise; Campbell, Matthew P; Rudd, Pauline M

    2011-11-01

    This Viewpoint article addresses comments made on our original article describing a symbolic system for the depiction of N- and O-linked carbohydrate structures and proposes a method for extending the symbol set to include monosaccharides commonly found in carbohydrates present in bacteria and plants. As before, basic monosaccharides are shown by shape with one or more additions such as solid fill or additions of lines, crosses or dots to represent functional groups. The use of colour to differentiate constituent monosaccharides is avoided, thus enabling the system to be used in a variety of formats. Linkage and anomericity are shown by the angle and type of line connecting the symbols. In this extended version, new symbols are proposed for additional hexoses and it is proposed that pyranose and furanose forms of the monosaccharides could be shown by solid or broken outlines to the symbols. Conventions for depicting the presence of multiple functional groups such as deoxy-(NH(2))(2) are also discussed. It is hoped that these proposals will stimulate discussion so that a consensus can be reached as to how the glycobiology community can best convey complex information in a simple manner. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Effect of annealing temperature on the structural, photoluminescence and magnetic properties of sol-gel derived Magnetoplumbite-type (M-type) hexagonal strontium ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Teh, Geok Bee, E-mail: sharonteh2009@gmail.com [Division of Bioscience and Chemistry, School of Arts and Science, Tunku Abdul Rahman College, Jalan Genting Kelang, 53300 Kuala Lumpur (Malaysia); Wong, Yat Choy [Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, PO Box 218, Hawthorn, Victoria 3122 (Australia); Tilley, Richard D. [School of Chemical and Physical Sciences, MacDiarmid Institute of Advanced Materials and Nanotechnology, Victoria University of Wellington, PO Box 600, Wellington (New Zealand)

    2011-09-15

    Magnetoplumbite-type (M-type) hexagonal strontium ferrite particles were synthesized via sol-gel technique employing ethylene glycol as the gel precursor at two different calcination temperatures (800 and 1000 deg. C). Structural properties were systematically investigated via X-ray diffraction (XRD), field emission scanning electron microscopy, high resolution transmission electron microscopy (HRTEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), photoluminescence spectrophotometry and superconducting quantum interference device magnetometer. XRD results showed that the sample synthesized at 1000 deg. C was of single-phase with a space group of P6{sub 3}/mmc and lattice cell parameter values of a=5.882 A and c=23.048 A. EDS confirmed the composition of strontium ferrite calcined at 1000 deg. C being mainly of M-type SrFe{sub 12}O{sub 19} with HRTEM micrographs confirming the ferrites exhibiting M-type long range ordering along the c-axis of the crystal structure. The photoluminescence (PL) property of strontium ferrite was examined at excitation wavelengths of 260 and 270 nm with significant PL emission peaks centered at 350 nm being detected. Strontium ferrite annealed at higher temperature (1000 deg. C) was found to have grown into larger particle size, having higher content of oxygen vacancies and exhibited 83-85% more intense PL. Both the as-prepared strontium ferrites exhibited significant oxygen vacancies defect structures, which were verified via TGA. Higher calcination temperature turned strontium ferrite into a softer ferrite. - Highlights: > High annealing temperature produced M-type ferrite with higher oxygen vacancies. > Photoluminescence intensity is proportional to the existence of oxygen vacancies. > XRD data showed cell contraction well suited to the change of oxygen vacancies. > Shift in hysteresis loop due to defect-induced exchange bias was observed.

  18. Radiation stimulated effects in crystals of quartz and berlinit with different type and degree of perfection structure

    CERN Document Server

    Ibragimov, Z D

    2001-01-01

    of structure. The effectiveness of creation of additional defects near defects of one type is increased with growth of concentration of other types of structure violations. It was established that in crystals of quartz and berlinit alpha-beta-transition during neutron irradiation occurs through formation of seeds of beta-phase. It was shown that the grown layer with beta-phase inherited also neutron induced defects of alpha-phase as well as defects related to beta-phase of quartz. The structure of amorphous phase formed around seeds of beta-phase differs from quartz glass structure. The formation of regions with structure closed to quartz glass structure occurs after definite neutron fluence values. In quartz crystals there are several defect centers emitting in red spectral range. The processes of impact and non-impact production of point defects, mechanisms of structure transformations in quartz and berlinit crystals irradiated by various types of radiation with over- and sub- threshold energy were studied....

  19. Evaluation of seismic performance and effectiveness of multiple slim-type damper system for seismic response control of building structures.

    Science.gov (United States)

    Kim, David; Sung, Eun Hee; Park, Kwan-Soon; Park, Jaegyun

    2014-01-01

    This paper presents the evaluation of seismic performance and cost-effectiveness of a multiple slim-type damper system developed for the vibration control of earthquake excited buildings. The multiple slim-type damper (MSD) that consists of several small slim-type dampers and linkage units can control damping capacity easily by changing the number of small dampers. To evaluate the performance of the MSD, dynamic loading tests are performed with three slim-type dampers manufactured at a real scale. Numerical simulations are also carried out by nonlinear time history analysis with a ten-story earthquake excited building structure. The seismic performance and cost-effectiveness of the MSD system are investigated according to the various installation configurations of the MSD system. From the results of numerical simulation and cost-effectiveness evaluation, it is shown that combinations of the MSD systems can effectively improve the seismic performance of earthquake excited building structures.

  20. Evaluation of Seismic Performance and Effectiveness of Multiple Slim-Type Damper System for Seismic Response Control of Building Structures

    Science.gov (United States)

    Kim, David; Sung, Eun Hee; Park, Kwan-Soon; Park, Jaegyun

    2014-01-01

    This paper presents the evaluation of seismic performance and cost-effectiveness of a multiple slim-type damper system developed for the vibration control of earthquake excited buildings. The multiple slim-type damper (MSD) that consists of several small slim-type dampers and linkage units can control damping capacity easily by changing the number of small dampers. To evaluate the performance of the MSD, dynamic loading tests are performed with three slim-type dampers manufactured at a real scale. Numerical simulations are also carried out by nonlinear time history analysis with a ten-story earthquake excited building structure. The seismic performance and cost-effectiveness of the MSD system are investigated according to the various installation configurations of the MSD system. From the results of numerical simulation and cost-effectiveness evaluation, it is shown that combinations of the MSD systems can effectively improve the seismic performance of earthquake excited building structures. PMID:25301387

  1. Coder and decoder of fractal signals of comb-type structure

    Directory of Open Access Journals (Sweden)

    Politanskyi R. L.

    2014-08-01

    Full Text Available The article presents a coder and decoder of fractal signals of comb-type structure (FSCS based on microcontrollers (MC. The coder and decoder consist of identical control modules, while their managed modules have different schematic constructions. The control module performs forming or recognition of signals, and also carries out the function of information exchange with a computer. The basic element of the control module is a PIC18F2550 microcontroller from MicroChip. The coder of the system forms fractal signals of a given order according to the information bits coming from the computer. Samples of the calculated values of the amplitudes of elementary rectangular pulses that constitute the structure of fractal pulses are stored in the memory of the microcontroller as a table. Minimum bit capacity of the DAC necessary for the generation of FSCS of fourth order is four bits. The operation algorithm, "wired" into the controller of the program, provides for encoding of the transmitted information by two-bit symbols. Recognition of the start of transmission of each byte in communication channel is performed by the transmission of the timing signal. In a decoder the microcontroller carries out reception and decoding of the received fractal signals which are then transmitted to the computer. The developed algorithm of the program for the microcontroller of the decoder is carried out by determination of order of fractal impulse after the value of sum of amplitudes of elementary impulses, constituents fractal signal. The programs for coder and decoder are written in "C". In the most critical places of the program influencing on the fast-acting of chart “assembler” insertions are done. The blocks of the coder and decoder were connected with a coaxial 10 meters long cable with an impendance of 75 Ohm. The signals generated by the developed coder of FSCS, were studied using a digital oscillograph. On the basis of the obtained spectrums, it is possible

  2. Magnetic field structure in single late-type giants: the effectively single giant V390 Aurigae

    Science.gov (United States)

    Konstantinova-Antova, R.; Aurière, M.; Petit, P.; Charbonnel, C.; Tsvetkova, S.; Lèbre, A.; Bogdanovski, R.

    2012-05-01

    Aims: We have studied the active giant V390 Aur using spectropolarimetry to obtain direct and simultaneous measurements of the magnetic field and the activity indicators to obtain a precise insight of its activity. Methods: We used the spectropolarimeter NARVAL at the Bernard Lyot Telescope (Observatoire du Pic du Midi, France) to obtain a series of Stokes I and Stokes V profiles. Using the least-squares deconvolution (LSD) technique we were able to detect the Zeeman signature of the magnetic field in each of our 13 observations and to measure its longitudinal component. Using the wide wavelength range of the spectra we were able to monitor the CaII K&H and IR triplet, as well as the Hα lines, which are activity indicators. To reconstruct the magnetic field geometry of V390 Aur on the basis of modelling the Stokes V profiles, we applied the Zeeman Doppler imaging (ZDI) inversion method and present a map for the magnetic field. Based on the obtained spectra, we also refined the fundamental parameters of the star and the Li abundance using MARCS model atmospheres. Results: The ZDI revealed a structure in the radial magnetic field consisting of a polar magnetic spot of positive polarity and several negative spots at lower latitude. A high latitude belt is present on the azimuthal field map, indicative of a toroidal field close to the surface. Similar features are observed in some RS CVn and FK Com -type stars. It was found that the photometric period cannot fit the behaviour of the activity indicators formed in the chromosphere. Their behaviour suggests slower rotation compared to the photosphere, but our dataset is too short for us to be able to estimate their exact periods. All these results can be explained in terms of an α - ω dynamo operation, taking into account the stellar structure and rotation properties of V390 Aur that we studied with up-to-date stellar models computed at solar metallicity with the code STAREVOL. The calculated Rossby number also points

  3. Switchable subwavelength plasmonic structures with phase-change materials for reflection-type active metasurfaces in the visible region

    Science.gov (United States)

    Hwang, Chi-Young; Lee, Seung-Yeol; Kim, Yong-Hae; Kim, Tae-Youb; Kim, Gi Heon; Yang, Jong-Heon; Pi, Jae-Eun; Choi, Ji Hun; Choi, Kyunghee; Kim, Hee-Ok; Hwang, Chi-Sun

    2017-12-01

    In this work, a switchable plasmonic structure is proposed for reflection-type spatial light modulation in the visible range with subwavelength resolution. This structure is based on a metallic grating in which each resonant cavity couples the incident light into a gap surface plasmon mode and then reflects the light modulated in the cavity. By incorporating an ultrathin layer of the phase-change material Ge2Sb2Te5 at the entrance of the cavity, the optical modulation characteristic of the structure can be switched between two modes. Numerical investigations are conducted to verify the proposed structure, with the focused analysis of two common types of binary modulations: amplitude-only and phase-only modulations.

  4. Riemann type algebraic structures and their differential-algebraic integrability analysis

    Directory of Open Access Journals (Sweden)

    Prykarpatsky A.K.

    2010-06-01

    Full Text Available The differential-algebraic approach to studying the Lax type integrability of generalized Riemann type equations is devised. The differentiations and the associated invariant differential ideals are analyzed in detail. The approach is also applied to studying the Lax type integrability of the well known Korteweg-de Vries dynamical system.

  5. Phytoplankton community structure in local water types at a coastal site in north-western Bay of Bengal.

    Science.gov (United States)

    Baliarsingh, S K; Srichandan, Suchismita; Lotliker, Aneesh A; Sahu, K C; Srinivasa Kumar, T

    2016-07-01

    A comprehensive analysis on seasonal distribution of phytoplankton community structure and their interaction with environmental variables was carried out in two local water types (type 1  30 m isobath) at a coastal site in north-western Bay of Bengal. Phytoplankton community was represented by 211 taxa (146 marine, 37 fresh, 2 brackish, 20 marine-fresh, and 6 marine-brackish-fresh) belonging to seven major groups including 45 potential bloom forming and 22 potential toxin producing species. The seasonal variability depicted enrichment of phytoplankton during pre-monsoon in both water types. Total phytoplankton abundance pattern observed with inter-annual shift during monsoon and post-monsoon period at both water types. In both water types, diatom predominance was observed in terms of species richness and abundance comprising of centric (82 sp.) and pennate (58 sp.) forms. Pennate diatoms, Thalassiothrix longissima and Skeletonema costatum preponderated in both the water types. The diatom abundance was higher in type 1 in comparison to type 2. In general, SiO4 found to fuel growth of the dominant phytoplankton group, diatom in both the water types despite comparative lower concentration of other macronutrients in type 2.

  6. Stereotypic and complex phrase types provide structural evidence for a multi-message display in humpback whales (Megaptera novaeangliae).

    Science.gov (United States)

    Murray, Anita; Dunlop, Rebecca A; Noad, Michael J; Goldizen, Anne W

    2018-02-01

    Male humpback whales produce a mating display called "song." Behavioral studies indicate song has inter- and/or intra-sexual functionality, suggesting song may be a multi-message display. Multi-message displays often include stereotypic components that convey group membership for mate attraction and/or male-male interactions, and complex components that convey individual quality for courtship. Humpback whale song contains sounds ("units") arranged into sequences ("phrases"). Repetitions of a specific phrase create a "theme." Within a theme, imperfect phrase repetitions ("phrase variants") create variability among phrases of the same type ("phrase type"). The hypothesis that song contains stereotypic and complex phrase types, structural characteristics consistent with a multi-message display, is investigated using recordings of 17 east Australian males (8:2004, 9:2011). Phrase types are categorized as stereotypic or complex using number of unit types, number of phrase variants, and the proportion of phrases that is unique to an individual versus shared amongst males. Unit types are determined using self-organizing maps. Phrase variants are determined by Levenshtein distances between phrases. Stereotypic phrase types have smaller numbers of unit types and shared phrase variants. Complex phrase types have larger numbers of unit types and unique phrase variants. This study supports the hypothesis that song could be a multi-message display.

  7. Identification of promising chemical systems for the synthesis of new materials structure types: An ab initio minimization data mining approach

    Directory of Open Access Journals (Sweden)

    Dejan Zagorac

    2013-03-01

    Full Text Available In this research we performed data exploring for binary compounds with elements from groups V, IV-VI, and III-VII, with the goal to identify chemical systems where the recently proposed “5-5” structure type might be experimentally accessible. Among others, TlF, SnO, SnS, SnSe, GeS, GeSe, PbO, PbS, ZnO and ZnS, were chosen for the study. For each of these systems, a local optimization on ab initio level with the LDA functional was performed for the 5-5 structure type, plus other experimentally observed and theoretically proposed structure types, for comparison. Afterwards, the results were combined with earlier theoretical work involving the 5-5 structure in the earth alkaline metal oxides and the alkali metal halides. As a result, we suggest the GeSe and the ZnO systems as the most suitable ones for synthesizing the 5-5 structure type.

  8. Regional factors rather than forest type drive the community structure of soil living oribatid mites (Acari, Oribatida).

    Science.gov (United States)

    Erdmann, Georgia; Scheu, Stefan; Maraun, Mark

    2012-06-01

    Most European forests are managed by humans. However, the manner and intensity of management vary. While the effect of forest management on above-ground communities has been investigated in detail, effects on the below-ground fauna remain poorly understood. Oribatid mites are abundant microarthropods in forest soil and important decomposers in terrestrial ecosystems. Here, we investigated the effect of four forest types (i.e., managed coniferous forests; 30 and 70 years old managed beech forests; natural beech forests) on the density, diversity and community structure of oribatid mites (Acari). The study was replicated at three regions in Germany: the Swabian Alb, the Hainich and the Schorfheide. To relate changes in oribatid mite community structure to environmental factors, litter mass, pH, C and N content of litter, fine roots and C content of soil were measured. Density of oribatid mites was highest in the coniferous forests and decreased in the order 30 years old, 70 years old, and natural beech forests. Mass of the litter layer and density of oribatid mites were strongly correlated indicating that the litter layer is an important factor regulating oribatid mite densities. Diversity of oribatid mites was little affected by forest type indicating that they harbor similar numbers of niches. Species composition differed between the forest types, suggesting different types of niches. The community structure of oribatid mites differed more strongly between the three regions than between the forest types indicating that regional factors are more important than effects associated with forest type.

  9. Complete {sup 1}H and {sup 13}C NMR structural assignments for a group of four goyazensolide-type furanoheliangolides

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Ana Carolina Ferreira; Silva, Aline Nazare; Matos, Priscilla Mendonca; Silva, Eder Henrique da; Heleno, Vladimir Constantino Gomes [Universidade de Franca, Franca, SP (Brazil). Nucleo de Pesquisas em Ciencias Exatas e Tecnologicas; Lopes, Norberto Peporine; Lopes, Joao Luis Callegari [Universidade de Sao Paulo (FCFRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Ciencias Farmaceuticas de Ribeirao Preto. Dept. de Quimica e Fisica; Sass, Daiane Cristina, E-mail: vheleno_05@yahoo.com.br [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Filosofia, Ciencias e Letras de Ribeirao Preto. Dept. de Quimica

    2012-07-01

    Four goyazensolide-type sesquiterpene lactones - lychnofolide, centratherin, goyazensolide and goyazensolide acetate - were thoroughly studied by NMR experimental techniques. {sup 1}H NMR, {sup 13}C NMR {l_brace}{sup 1}H{r_brace}, COSY, HMQC, HMBC, J-res. and NOE experiments were performed to provide the needed structural information. Complete and unequivocal assignment, including the determination of all multiplicities, was obtained for each structure and the data collections are presented in tables (author)

  10. A strategy for depositing different types of cells in three dimensions to mimic tubular structures in tissues.

    Science.gov (United States)

    Yuan, Bo; Jin, Yu; Sun, Yi; Wang, Dong; Sun, Jiashu; Wang, Zhuo; Zhang, Wei; Jiang, Xingyu

    2012-02-14

    The fabrication of tubular structures, with multiple cell types forming different layers of the tube walls, is described using a stress-induced rolling membrane (SIRM). Cell orientation inside the tubes can also be controlled by topographical contact guidance. These layered tubes precisely mimic blood vessels and many other tubular structures, suggesting that they may be of great use in tissue engineering. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Potential Use of Avocado Oil on Structured Lipids MLM-Type Production Catalysed by Commercial Immobilised Lipases

    OpenAIRE

    Caballero, Eduardo; Soto, Carmen; Olivares, Araceli; Altamirano, Claudia

    2014-01-01

    Structured Lipids are generally constituents of functional foods. Growing demands for SL are based on a fuller understanding of nutritional requirements, lipid metabolism, and improved methods to produce them. Specifically, this work was aimed to add value to avocado oil by producing dietary triacylglycerols (TAG) containing medium-chain fatty acids (M) at positions sn-1,3 and long-chain fatty acids (L) at position sn-2. These MLM-type structured lipids (SL) were produced by interesterificati...

  12. Complete ¹H and 13C NMR structural assignments for a group of four goyazensolide-type furanoheliangolides

    Directory of Open Access Journals (Sweden)

    Ana Carolina Ferreira Soares

    2012-01-01

    Full Text Available Four goyazensolide-type sesquiterpene lactones - lychnofolide, centratherin, goyazensolide and goyazensolide acetate - were thoroughly studied by NMR experimental techniques. ¹H NMR, 13C NMR {¹H}, COSY, HMQC, HMBC, J-res. and NOE experiments were performed to provide the needed structural information. Complete and unequivocal assignment, including the determination of all multiplicities, was obtained for each structure and the data collections are presented in tables.

  13. Cytotoxic lanostane-type triterpenoids from the fruiting bodies of Ganoderma lucidum and their structure?activity relationships

    OpenAIRE

    Chen, Shaodan; Li, Xiangmin; Yong, Tianqiao; Wang, Zhanggen; Su, Jiyan; Jiao, Chunwei; Xie, Yizhen; Yang, Burton B.

    2016-01-01

    We conducted a study of Ganoderma lucidum metabolites and isolated 35 lanostane-type triterpenoids, including 5 new ganoderols (1-5). By spectroscopy, we compared the structures of these compounds with known related compounds in this group. All of the isolated compounds were assayed for their effect against the human breast carcinoma cell line MDA-MB-231 and hepatocellular carcinoma cell line HepG2. Corresponding three-dimensional quantitative structure?activity relationship (3D-QSAR) models ...

  14. Measuring the Growth Rate of Structure with Type IA Supernovae from LSST

    Science.gov (United States)

    Howlett, Cullan; Robotham, Aaron S. G.; Lagos, Claudia D. P.; Kim, Alex G.

    2017-10-01

    We investigate the peculiar motions of galaxies up to z = 0.5 using Type Ia supernovae (SNe Ia) from the Large Synoptic Survey Telescope (LSST) and predict the subsequent constraints on the growth rate of structure. We consider two cases. Our first is based on measurements of the volumetric SNe Ia rate and assumes we can obtain spectroscopic redshifts and light curves for varying fractions of objects that are detected pre-peak luminosity by LSST (some of which may be obtained by LSST itself, and others that would require additional follow-up observations). We find that these measurements could produce growth rate constraints at zRSD) with DESI or 4MOST, even though there are ˜ 4× fewer objects. For our second case, we use semi-analytic simulations and a prescription for the SNe Ia rate as a function of stellar mass and star-formation rate to predict the number of LSST SNe IA whose host redshifts may already have been obtained with the Taipan+WALLABY surveys or with a future multi-object spectroscopic survey. We find ˜18,000 and ˜160,000 SNe Ia with host redshifts for these cases, respectively. While this is only a fraction of the total LSST-detected SNe Ia, they could be used to significantly augment and improve the growth rate constraints compared to only RSD. Ultimately, we find that combining LSST SNe Ia with large numbers of galaxy redshifts will provide the most powerful probe of large-scale gravity in the z< 0.5 regime over the coming decades.

  15. Structural model for dihydropyridine binding to L-type calcium channels.

    Science.gov (United States)

    Tikhonov, Denis B; Zhorov, Boris S

    2009-07-10

    1,4-Dihydropyridines (DHPs) constitute a major class of ligands for L-type Ca(2+) channels (LTCC). The DHPs have a boat-like, six-membered ring with an NH group at the stern, an aromatic moiety at the bow, and substituents at the port and starboard sides. Various DHPs exhibit antagonistic or agonistic activities, which were previously explained as stabilization or destabilization, respectively, of the closed activation gate by the portside substituents. Here we report a novel structural model in which agonist and antagonist activities are determined by different parts of the DHP molecule and have different mechanisms. In our model, which is based on Monte Carlo minimizations of DHP-LTCC complexes, the DHP moieties at the stern, bow, and starboard form H-bonds with side chains of the key DHP-sensing residues Tyr_IIIS6, Tyr_IVS6, and Gln_IIIS5, respectively. We propose that these H-bonds, which are common for agonists and antagonists, stabilize the LTCC conformation with the open activation gate. This explains why both agonists and antagonists increase probability of the long lasting channel openings and why even partial disruption of the contacts eliminates the agonistic action. In our model, the portside approaches the selectivity filter. Hydrophobic portside of antagonists may induce long lasting channel closings by destabilizing Ca(2+) binding to the selectivity filter glutamates. Agonists have either hydrophilic substituents or a hydrogen atom at their portside, and thus lack this destabilizing effect. The predicted orientation of the DHP core allows accommodation of long substituents in the domain interface or in the inner pore. Our model may be useful for developing novel clinically relevant LTCC blockers.

  16. Structural Model for Dihydropyridine Binding to L-type Calcium Channels*

    Science.gov (United States)

    Tikhonov, Denis B.; Zhorov, Boris S.

    2009-01-01

    1,4-Dihydropyridines (DHPs) constitute a major class of ligands for L-type Ca2+ channels (LTCC). The DHPs have a boat-like, six-membered ring with an NH group at the stern, an aromatic moiety at the bow, and substituents at the port and starboard sides. Various DHPs exhibit antagonistic or agonistic activities, which were previously explained as stabilization or destabilization, respectively, of the closed activation gate by the portside substituents. Here we report a novel structural model in which agonist and antagonist activities are determined by different parts of the DHP molecule and have different mechanisms. In our model, which is based on Monte Carlo minimizations of DHP-LTCC complexes, the DHP moieties at the stern, bow, and starboard form H-bonds with side chains of the key DHP-sensing residues Tyr_IIIS6, Tyr_IVS6, and Gln_IIIS5, respectively. We propose that these H-bonds, which are common for agonists and antagonists, stabilize the LTCC conformation with the open activation gate. This explains why both agonists and antagonists increase probability of the long lasting channel openings and why even partial disruption of the contacts eliminates the agonistic action. In our model, the portside approaches the selectivity filter. Hydrophobic portside of antagonists may induce long lasting channel closings by destabilizing Ca2+ binding to the selectivity filter glutamates. Agonists have either hydrophilic substituents or a hydrogen atom at their portside, and thus lack this destabilizing effect. The predicted orientation of the DHP core allows accommodation of long substituents in the domain interface or in the inner pore. Our model may be useful for developing novel clinically relevant LTCC blockers. PMID:19416978

  17. Immunogold fine structural localization of extracellular matrix components in aged human cornea. I. Types I-IV collagen and laminin.

    Science.gov (United States)

    Marshall, G E; Konstas, A G; Lee, W R

    1991-01-01

    Using the immunogold technique combined with cryoultramicrotomy and London Resin white (LR white) embedding, we studied the fine structural distribution of types I-IV collagen and laminin in corneal tissue from seven enucleated human eyes (age range, 63-78 years). Type II collagen was not identified in any corneal layer. Type I and type III collagen were distributed in a similar fashion in striated collagen fibrils in Bowman's layer and in the stroma. Type IV collagen was located only in the posterior non-banded region of Descemet's membrane. Laminin was identified in subepithelial anchoring plaques and the sub-endothelial region of Descemet's membrane in accordance with its recognized adhesive function.

  18. Development Directions for Various Types of the Light Wood-Framed Structures

    Science.gov (United States)

    Malesza, J.; Baszeń, M.; Miedziałowski, Cz

    2017-11-01

    The paper presents current trends in the development of the wood-framed structures. Authors describe the evolution of the technology of implementation, the production process of precast elements of buildings as well as selected realization on the site of these kinds of structures. The attention has been paid to the effect of implementation phases on construction and erecting technology of the wood-framed structures. The paper draws attention to the importance and enhancement of structural analysis of structures in individual phases of building realization.

  19. Response Analyses of Tuned Mass Dampers to Structures Exposed to Vortex Loading of Simiu-Scanlan Type

    DEFF Research Database (Denmark)

    Andersen, Lars; Birch, N. W.; Hansen, A. H.

    2001-01-01

    Vortex-induced loads on slender one-dimensional structures vibrating at lock-in conditions consist of a self-induced part in phase with the velocity of the structure in addition to an additive, almost harmonially varying component representing the same type of load as the vortex-induced force...... on a fixed cylinder. Simiu and Scanlan (1996 Wind Effects on Structures. New York: John Wiley & Sons Inc.) have proposed a widely used model for the self-induced part of the load based on a van der Pol oscillator. The aim of this paper is to investigate the optimal design of tuned mass dampers...

  20. Vortices and magnetic structures of the target type in two-dimensional ferromagnetics with the anisotropic exchange interaction

    CERN Document Server

    Borisov, A B; Mikushina, N A; Moskvin, A S

    2002-01-01

    One investigated into structure of vortices and of other topological defects in two-dimensional Heisenberg ferromagnet. Paper contains basic data derived from microscopic theory of spin anisotropy in 3d- and 4f-element base systems. One studied effect of parameters of anisotropic exchange and single-ionic anisotropy on vortex structure. One studied magnetization vortices in freely plane ferromagnetic with anisotropic exchange and local anisotropy. One predicted and analyzed structure of a new class of static leading centre (target) type vortex configurations in anisotropic ferromagnet

  1. The effect of fabric structural parameters and fiber type on the comfort-related properties of commercial apparel fabrics

    CSIR Research Space (South Africa)

    Stoffberg, ME

    2015-10-01

    Full Text Available The effect of fabric structural parameters and fiber type on the comfort-related properties, namely water vapor resistance and thermal resistance, of commercial apparel (suiting) fabrics, containing both natural and man-made fibers have been studied...

  2. Lack of immunogenicity of ice structuring protein type III HPLC12 preparation administered by the oral route to human volunteers

    DEFF Research Database (Denmark)

    Crevel, R W R; Cooper, K J; Poulsen, Lars K.

    2007-01-01

    Before a novel protein can be used in foods, its potential allergenicity must be assessed. In this study, healthy volunteers consumed ice structuring protein (ISP) Type III preparation or a control material 5 days a week for a total of 8 weeks. General measures of health were recorded during...

  3. Spiro-bridged ladder-type poly(p-phenylene)s: towards structurally perfect light-emitting materials.

    Science.gov (United States)

    Wu, Yonggang; Zhang, Jianyuan; Fei, Zhuping; Bo, Zhishan

    2008-06-11

    Structurally perfect spiro-bridged ladder-type poly(p-phenylene)s, which show blue fluorescence in the photoluminescence (PL) and electroluminescence (EL) emission spectra, are prepared by Suzuki-Miyaura polycondensation and Friedel-Crafts cyclization. The polymers are free of ketonic defects, exhibiting excellent thermal and color stability upon annealing in air at 110 degrees C for 24 h.

  4. Structured exercise interventions for type 2 diabetes mellitus: Strength of current evidence

    Directory of Open Access Journals (Sweden)

    Mohammed Ejas Hussain

    2011-07-01

    Full Text Available Exercise, along with medical nutrition therapy and pharmacological interventions, is an important component in the clinical management of type 2 diabetes mellitus (T2D. Current clinical guidelines on type 2 diabetes provide no detailed information on the modalities of effective exercise intervention in the treatment of type 2 diabetes. Both endurance and resistance types of exercise seem to be equally effective in improving metabolic control in patients with type 2 diabetes. Determining the best method of providing exercise is clinically relevant to this population. This paper reviews the epidemiology of diabetes and problems of physical function associated with type 2 diabetes and discuss the benefits of exercise therapy on the parameters of glycemic control and function in type 2 diabetes patients, with special reference to Asian Indians. Based on the currently available literature, it is concluded that type 2 diabetes patients should be encouraged to participate in specifically designed exercise intervention programs. Attention should be paid to the avoidance of cardiovascular and musculoskeletal deconditioning. More clinical research is warranted to establish the efficacy of different dosages of exercise intervention in a holistic approach for type 2 diabetes subpopulations within different stages of the disease and various levels of co-morbidity.

  5. Call types of Bigg's killer whales (Orcinus orca) in western Alaska: Using vocal dialects to assess population structure

    Science.gov (United States)

    Sharpe, Deborah Lynn

    Apex predators are important indicators of ecosystem health, but little is known about the population structure of Bigg's killer whales ( Orcinus orca; i.e. 'transient' ecotype) in western Alaska. Currently, all Bigg's killer whales in western Alaska are ascribed to a single broad stock for management under the US Marine Mammal Protection Act. However, recent nuclear microsatellite and mitochondrial DNA analyses indicate that this stock is likely comprised of genetically distinct sub-populations. In accordance with what is known about killer whale vocal dialects in other locations, I sought to evaluate Bigg's killer whale population structure by examining the spatial distribution of group-specific call types in western Alaska. Digital audio recordings were collected from 33 encounters with Bigg's killer whales throughout the Aleutian and Pribilof Islands in the summers of 2001-2007 and 2009-2010. Recorded calls were perceptually classified into discrete types and then quantitatively described using 12 structural and time-frequency measures. Resulting call categories were objectively validated using a random forest approach. A total of 36 call types and subtypes were identified across the entire study area, and regional patterns of call type usage revealed three distinct dialects, each of which corresponding to proposed genetic delineations. I suggest that at least three acoustically and genetically distinct subpopulations are present in western Alaska, and put forth an initial catalog for this area describing the regional vocal repertoires of Bigg's killer whale call types.

  6. Social influence and adolescent health-related physical activity in structured and unstructured settings: role of channel and type.

    Science.gov (United States)

    Spink, Kevin S; Wilson, Kathleen S; Ulvick, Jocelyn

    2012-08-01

    Social influence channels (e.g., parents) and types (e.g., compliance) have each been related to physical activity independently, but little is known about how these two categories of influence may operate in combination. This study examined the relationships between various combinations of social influence and physical activity among youth across structured and unstructured settings. Adolescents (N=304), classified as high or low active, reported the social influence combinations they received for being active. Participants identified three channels and three types of influence associated with being active. For structured activity, compliance with peers and significant others predicted membership in the high active group (values of psetting, peer compliance (p= .009) and conformity (p= .019) were associated with active group membership. These findings reinforce considering both setting, as well as the channel/type combinations of social influence, when examining health-related physical activity.

  7. Structure of the cytoplasmic domain of Yersinia pestis YscD, an essential component of the type III secretion system

    Energy Technology Data Exchange (ETDEWEB)

    Lountos, George T.; Tropea, Joseph E.; Waugh, David S. (SAIC); (NCI)

    2012-09-17

    The Yersinia pestis YscD protein is an essential component of the type III secretion system. YscD consists of an N-terminal cytoplasmic domain (residues 1-121), a transmembrane linker (122-142) and a large periplasmic domain (143-419). Both the cytoplasmic and the periplasmic domains are required for the assembly of the type III secretion system. Here, the structure of the YscD cytoplasmic domain solved by SAD phasing is presented. Although the three-dimensional structure is similar to those of forkhead-associated (FHA) domains, comparison with the structures of canonical FHA domains revealed that the cytoplasmic domain of YscD lacks the conserved residues that are required for binding phosphothreonine and is therefore unlikely to function as a true FHA domain.

  8. Structural Elucidation of α-Cyclodextrin-Succinic Acid Pseudo Dodecahydrate: Expanding the Packing Types of α-Cyclodextrin Inclusion Complexes

    Directory of Open Access Journals (Sweden)

    Sofiane Saouane

    2015-12-01

    Full Text Available This paper reports a new packing type of α-cyclodextrin inclusion complexes, obtained here with succinic acid under low-temperature crystallization conditions. The structure of the 1:1 complex is characterized by heavy disorder of the guest, the solvent, and part of the host. The crystal packing belongs to the known channel-type structure; the basic structural unit is composed of cyclodextrin trimers, as opposed to the known isolated molecular or dimeric constructs, packed along the c-axis. Each trimer is made of crystallographically independent molecules assembled in a stacked vase-like cluster. A multi-temperature single-crystal X-ray diffraction analysis reveals the presence of dynamic disorder.

  9. Age-dependent changes of the immunohistochemical distribution of various collagen types and structural glycoproteins in the human uterine tube.

    Science.gov (United States)

    Schultka, R; Göpel, C; Schuppan, D; Schmidt, T

    1993-12-01

    This immunohistochemical investigation deals with the age-dependent localization and distribution of types I, III, IV, V, and VI collagen and the structural glycoproteins undulin, fibronectin, laminin, tenascin, and vitronectin in the connective tissue of the human uterine tube. The stroma of this oviductal region consisted of all collagen types. Collagen types I and VI were distributed throughout the connective tissue of the mucosa reaching the basal membrane. The findings suggest that the amount of these collagen types and type III collagen increases in relation to age, since the coarser fibres of the mucosal stroma in the uterine tubes of older women were strongly labelled by immunohistochemistry. The pattern of undulin reactivity was similar to that of types I and VI collagen. The exact quantitative proportions of age-related oviductal changes for types I, III, and VI as well as of undulin are still unknown. Type V collagen was associated with a fine fibre meshwork in the mucosal stroma. The fibres reached the subepithelial zone which appeared membrane-like. The location of type V collagen-associated fibres and aldehyde fuchsin-positive fibres characterized in our previous studies appears to be identical. Moreover, the structural glycoproteins undulin, fibronectin, laminin, tenascin, and vitronectin were detected in the mucosal stroma. The staining of fibronectin was less pronounced than that of undulin. Laminin was located in the zone of the basal membrane, whereas tenascin was mainly found in the mucosal vessels. Contrary to these findings, tenascin showed a unique distribution in the region near the basis of the mucosal folds in the isthmic part. Vitronectin could be observed in the same region of the isthmic part of uterine tubes obtained from younger women. However, the zonal localization of vitronectin reactivity was absent in the isthmic part of older women.

  10. Structures and physical properties of epsilon-FeSi-type and CsCl-type RuSi studied by first-principles pseudopotential calculations

    Science.gov (United States)

    Vocadlo; Price; Wood

    2000-06-01

    An investigation of the relative stability of the two known polymorphs of RuSi, having the epsilon-FeSi and CsCl structures, has been made by first-principles pseudopotential calculations. The resulting cell volumes and fractional coordinates at P = 0 are in good agreement with experiment. Application of high pressure to the epsilon-FeSi phase of RuSi is predicted to produce a structure having almost perfect sevenfold coordination. However, it appears that RuSi having the CsCl-type structure will be the thermodynamically most stable phase for pressures greater than 3.6 GPa. Fitting of the calculated internal energy versus volume to a fourth-order logarithmic equation of state led to values (at T = 0 K) for the bulk modulus, K0, of 202 and 244 GPa for the epsilon-FeSi and CsCl phases, respectively, in excellent agreement with experiment. Band-structure calculations for both phases are also presented.

  11. Synthesis and structural characterization of RE7Zn21Tt2 (RE = La-Nd; Tt = Ge, Sn, and Pb): new structure type among the polar intermetallic phases.

    Science.gov (United States)

    Suen, Nian-Tzu; Bobev, Svilen

    2013-11-04

    Reported are 11 new ternary phases with the general formula RE7Zn21Tt2 (RE = La-Nd; Tt = Ge, Sn, and Pb), synthesized from the respective elements by reactions at high temperature. Their structures, established on the basis of single-crystal and powder X-ray diffraction work, are shown to be a new structure type with the orthorhombic space group Pbam (No. 55, Pearson symbol oP60). This complex atomic arrangement features condensed polyhedra made up of Zn atoms, interspersed by Ge, Sn, or Pb atoms in trigonal-planar coordination. The structure bears resemblance with the La3Al11 and the LaRhSn2 structure types, which are compared and discussed. Temperature dependent dc magnetization measurements confirm RE(3+) ground states for all rare-earth elements, and the expected local-moment magnetism due to the partial filling of their 4f states for RE(3+) = Ce(3+), Pr(3+), and Nd(3+). Theoretical considerations of the electronic structure based on the tight-binding linear muffin-tin orbital (TB-LMTO-ASA) method are also presented: the calculations support the experimental observation of a small, but not negligible, homogeneity range in RE7Zn(21+x)Tt(2-x) (x intermetallics.

  12. C-band disk-loaded-type accelerating structure for a high acceleration gradient and high-repetition-rate operation

    Directory of Open Access Journals (Sweden)

    T. Sakurai

    2017-04-01

    Full Text Available A high-acceleration-gradient linear accelerator (LINAC for an x-ray free electron laser (XFEL offers the advantages of a short accelerator length and low construction costs. In addition, the high pulse repetition rate of the LINAC, which can drive multiple x-ray beam lines, provides additional user opportunities for experiments involving XFEL. A C-band disk-loaded-type accelerating structure was developed to achieve a high acceleration gradient of >50  MV/m and an rf-pulse repetition rate of 120 pps, which is twice as high as that of the XFEL facility, SACLA (60 pps. The structure has a quasiconstant gradient and a traveling wave type with an accelerating mode of TM01−2π/3. To reduce the surface electric fields, we employed a cross section with an ellipsoidal curvature around an iris aperture. The accelerating structure was manufactured for SACLA. High-power rf conditioning was conducted to investigate its performance. Owing to the conditioning, the acceleration gradient reached a value of more than 50.1  MV/m. The structure was operated without any serious issues at a repetition rate of 120 pps. The accelerating structures were installed in the dedicated accelerator for EUV-FEL at SACLA beam line-1. Finally, we obtained accelerated electron beams with the structures operated at an acceleration gradient of 41.4  MV/m.

  13. C -band disk-loaded-type accelerating structure for a high acceleration gradient and high-repetition-rate operation

    Science.gov (United States)

    Sakurai, T.; Ego, H.; Inagaki, T.; Asaka, T.; Suzuki, D.; Miura, S.; Otake, Y.

    2017-04-01

    A high-acceleration-gradient linear accelerator (LINAC) for an x-ray free electron laser (XFEL) offers the advantages of a short accelerator length and low construction costs. In addition, the high pulse repetition rate of the LINAC, which can drive multiple x-ray beam lines, provides additional user opportunities for experiments involving XFEL. A C -band disk-loaded-type accelerating structure was developed to achieve a high acceleration gradient of >50 MV /m and an rf-pulse repetition rate of 120 pps, which is twice as high as that of the XFEL facility, SACLA (60 pps). The structure has a quasiconstant gradient and a traveling wave type with an accelerating mode of TM 01 -2 π /3 . To reduce the surface electric fields, we employed a cross section with an ellipsoidal curvature around an iris aperture. The accelerating structure was manufactured for SACLA. High-power rf conditioning was conducted to investigate its performance. Owing to the conditioning, the acceleration gradient reached a value of more than 50.1 MV /m . The structure was operated without any serious issues at a repetition rate of 120 pps. The accelerating structures were installed in the dedicated accelerator for EUV-FEL at SACLA beam line-1. Finally, we obtained accelerated electron beams with the structures operated at an acceleration gradient of 41.4 MV /m .

  14. The crystal structure of SDR-type pyridoxal 4-dehydrogenase of Mesorhizobium loti.

    Science.gov (United States)

    Chu, Huy Nhat; Kobayashi, Jun; Mikami, Bunzo; Yagi, Toshiharu

    2011-01-01

    Pyridoxal 4-dehydrogenase catalyzes the irreversible oxidation of pyridoxal to 4-pyridoxolactone and is involved in degradation pathway I of pyridoxine, a vitamin B(6) compound. Its crystal structure was elucidated for the first time. Molecular replacement with (S)-1-phenylthanol dehydrogenase (PDB code 2EW8) was adopted to determine the tertiary structure of the NAD(+)-bound enzyme.

  15. Application of high-throughput technologies to a structural proteomics-type analysis of Bacillus anthracis

    NARCIS (Netherlands)

    Au, K.; Folkers, G.E.; Kaptein, R.

    2006-01-01

    A collaborative project between two Structural Proteomics In Europe (SPINE) partner laboratories, York and Oxford, aimed at high-throughput (HTP) structure determination of proteins from Bacillus anthracis, the aetiological agent of anthrax and a biomedically important target, is described. Based

  16. Canopy structure on forest lands in western Oregon: differences among forest types and stand ages

    Science.gov (United States)

    Anne C.S. McIntosh; Andrew N. Gray; Steven L. Garman

    2009-01-01

    Canopy structure is an important attribute affecting economic and ecological values of forests in the Pacific Northwest. However, canopy cover and vertical layering are rarely measured directly; they are usually inferred from other forest measurements. In this study, we quantified and compared vertical and horizontal patterns of tree canopy structure and understory...

  17. Multi-virulence-locus sequence typing of Staphylococcus lugdunensis generates results consistent with a clonal population structure and is reliable for epidemiological typing.

    Science.gov (United States)

    Didi, Jennifer; Lemée, Ludovic; Gibert, Laure; Pons, Jean-Louis; Pestel-Caron, Martine

    2014-10-01

    Staphylococcus lugdunensis is an emergent virulent coagulase-negative staphylococcus responsible for severe infections similar to those caused by Staphylococcus aureus. To understand its potentially pathogenic capacity and have further detailed knowledge of the molecular traits of this organism, 93 isolates from various geographic origins were analyzed by multi-virulence-locus sequence typing (MVLST), targeting seven known or putative virulence-associated loci (atlLR2, atlLR3, hlb, isdJ, SLUG_09050, SLUG_16930, and vwbl). The polymorphisms of the putative virulence-associated loci were moderate and comparable to those of the housekeeping genes analyzed by multilocus sequence typing (MLST). However, the MVLST scheme generated 43 virulence types (VTs) compared to 20 sequence types (STs) based on MLST, indicating that MVLST was significantly more discriminating (Simpson's index [D], 0.943). No hypervirulent lineage or cluster specific to carriage strains was defined. The results of multilocus sequence analysis of known and putative virulence-associated loci are consistent with a clonal population structure for S. lugdunensis, suggesting a coevolution of these genes with housekeeping genes. Indeed, the nonsynonymous to synonymous evolutionary substitutions (dN/dS) ratio, the Tajima's D test, and Single-likelihood ancestor counting (SLAC) analysis suggest that all virulence-associated loci were under negative selection, even atlLR2 (AtlL protein) and SLUG_16930 (FbpA homologue), for which the dN/dS ratios were higher. In addition, this analysis of virulence-associated loci allowed us to propose a trilocus sequence typing scheme based on the intragenic regions of atlLR3, isdJ, and SLUG_16930, which is more discriminant than MLST for studying short-term epidemiology and further characterizing the lineages of the rare but highly pathogenic S. lugdunensis. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  18. Femoral fracture type can be predicted from femoral structure: A finite element study validated by digital volume correlation experiments.

    Science.gov (United States)

    Ridzwan, Mohamad Ikhwan Zaini; Sukjamsri, Chamaiporn; Pal, Bidyut; van Arkel, Richard J; Bell, Andrew; Khanna, Monica; Baskaradas, Aroon; Abel, Richard; Boughton, Oliver; Cobb, Justin; Hansen, Ulrich N

    2017-08-01

    Proximal femoral fractures can be categorized into two main types: Neck and intertrochanteric fractures accounting for 53% and 43% of all proximal femoral fractures, respectively. The possibility to predict the type of fracture a specific patient is predisposed to would allow drug and exercise therapies, hip protector design, and prophylactic surgery to be better targeted for this patient rendering fracture preventing strategies more effective. This study hypothesized that the type of fracture is closely related to the patient-specific femoral structure and predictable by finite element (FE) methods. Fourteen femora were DXA scanned, CT scanned, and mechanically tested to fracture. FE-predicted fracture patterns were compared to experimentally observed fracture patterns. Measurements of strain patterns to explain neck and intertrochanteric fracture patterns were performed using a digital volume correlation (DVC) technique and compared to FE-predicted strains and experimentally observed fracture patterns. Although loaded identically, the femora exhibited different fracture types (six neck and eight intertrochanteric fractures). CT-based FE models matched the experimental observations well (86%) demonstrating that the fracture type can be predicted. DVC-measured and FE-predicted strains showed obvious consistency. Neither DXA-based BMD nor any morphologic characteristics such as neck diameter, femoral neck length, or neck shaft angle were associated with fracture type. In conclusion, patient-specific femoral structure correlates with fracture type and FE analyses were able to predict these fracture types. Also, the demonstration of FE and DVC as metrics of the strains in bones may be of substantial clinical value, informing treatment strategies and device selection and design. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  19. Chemical composition, crystal structure, and their relationships with the intrinsic properties of spinel-type crystals based on bond valences.

    Science.gov (United States)

    Liu, Xiao; Wang, Hao; Lavina, Barbara; Tu, Bingtian; Wang, Weimin; Fu, Zhengyi

    2014-06-16

    Spinel-type crystals may possess complex and versatile chemical composition and crystal structure, which leads to difficulty in constructing relationships among the chemical composition, crystal structure, and intrinsic properties. In this work, we develop new empirical methods based on bond valences to estimate the intrinsic properties, namely, compressibility and thermal expansion of complex spinel-type crystals. The composition-weighted average of bond force constants in tetrahedral and octahedral coordination polyhedra is derived as a function of the composition-weighted average of bond valences, which can be calculated according to the experimental chemical composition and crystal structural parameters. We discuss the coupled effects of tetrahedral and octahedral frameworks on the aforementioned intrinsic properties. The bulk modulus could be quantitatively calculated from the composition-weighted average of bond force constants in tetrahedral and octahedral coordination polyhedra. In contrast, a quantitative estimation of the thermal expansion coefficient could be obtained from the composition-weighted average of bond force constants in octahedral coordination polyhedra. These empirical methods have been validated by the results obtained for a new complex quaternary spinel-type oxynitride Mg0.268Al2.577O3.733N0.267 as well as MgAl2O4 and Al2.85O3.45N0.55 from the literature. Further, these empirical methods have the potential to be extensively applied in other types of complex crystals.

  20. The structure of galactic disks - Studying late-type spiral galaxies using SDSS

    National Research Council Canada - National Science Library

    Pohlen, M; Trujillo, I

    2006-01-01

    Using imaging data from the SDSS survey, we present the g' and r' radial stellar light distribution of a complete sample of similar to 90 face-on to intermediate inclined, nearby, late-type (Sb-Sdm) spiral galaxies...

  1. Structure-activity relationships of lanostane-type triterpenoids from Ganoderma lingzhi as α-glucosidase inhibitors.

    Science.gov (United States)

    Fatmawati, Sri; Kondo, Ryuichiro; Shimizu, Kuniyoshi

    2013-11-01

    A series of lanostane-type triterpenoids, identified as ganoderma alcohols and ganoderma acids, were isolated from the fruiting body of Ganoderma lingzhi. Some of these compounds were confirmed as active inhibitors of the in vitro human recombinant aldose reductase. This paper aims to explain the structural requirement for α-glucosidase inhibition. Our structure-activity studies of ganoderma alcohols showed that the OH substituent at C-3 and the double-bond moiety at C-24 and C-25 are necessary to increase α-glucosidase inhibitory activity. The structure-activity relationships of ganoderma acids revealed that the OH substituent at C-11 is an important feature and that the carboxylic group in the side chain is essential for the recognition of α-glucosidase inhibitory activity. Moreover, the double-bond moiety at C-20 and C-22 in the side chain and the OH substituent at C-3 of ganoderma acids improve α-glucosidase inhibitory activity. These results provide an approach with which to consider the structural requirements of lanostane-type triterpenoids from G. lingzhi. An understanding of these requirements is considered necessary in order to improve a new type of α-glucosidase inhibitor. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. MWW-type titanosilicate synthesis, structural modification and catalytic applications to green oxidations

    CERN Document Server

    Wu, Peng; Xu, Le; Liu, Yueming; He, Mingyuan

    2013-01-01

    This book provides a comprehensive review of a new generation of selective oxidation titanosilicate catalysts with the MWW topology (Ti-MWW) based on the research achievements of the past 12 years. It gives an overview of the synthesis, structure modification and catalytic properties of Ti-MWW. Ti-MWW can readily be prepared by means of direct hydrothermal synthesis with crystallization-supporting agents, using dual-structure-directing agents and a dry-gel conversion technique. It also can be post-synthesized through unique reversible structure transformation and liquid-phase isomorphous subst

  3. Structure Analysis of Jungle-Gym-Type Gels by Brownian Dynamics Simulation

    Science.gov (United States)

    Ohta, Noriyoshi; Ono, Kohki; Takasu, Masako; Furukawa, Hidemitsu

    2008-02-01

    We investigated the structure and the formation process of two kinds of gels by Brownian dynamics simulation. The effect of flexibility of main chain oligomer was studied. From our results, hard gel with rigid main chain forms more homogeneous network structure than soft gel with flexible main chain. In soft gel, many small loops are formed, and clusters tend to shrink. This heterogeneous network structure may be caused by microgels. In the low density case, soft gel shows more heterogeneity than the high density case.

  4. Pyrosequencing-Based Assessment of Bacterial Community Structure Along Different Management Types in German Forest and Grassland Soils

    Science.gov (United States)

    Nacke, Heiko; Thürmer, Andrea; Wollherr, Antje; Will, Christiane; Hodac, Ladislav; Herold, Nadine; Schöning, Ingo; Schrumpf, Marion; Daniel, Rolf

    2011-01-01

    Background Soil bacteria are important drivers for nearly all biogeochemical cycles in terrestrial ecosystems and participate in most nutrient transformations in soil. In contrast to the importance of soil bacteria for ecosystem functioning, we understand little how different management types affect the soil bacterial community composition. Methodology/Principal Findings We used pyrosequencing-based analysis of the V2-V3 16S rRNA gene region to identify changes in bacterial diversity and community structure in nine forest and nine grassland soils from the Schwäbische Alb that covered six different management types. The dataset comprised 598,962 sequences that were affiliated to the domain Bacteria. The number of classified sequences per sample ranged from 23,515 to 39,259. Bacterial diversity was more phylum rich in grassland soils than in forest soils. The dominant taxonomic groups across all samples (>1% of all sequences) were Acidobacteria, Alphaproteobacteria, Actinobacteria, Betaproteobacteria, Deltaproteobacteria, Gammaproteobacteria, and Firmicutes. Significant variations in relative abundances of bacterial phyla and proteobacterial classes, including Actinobacteria, Firmicutes, Verrucomicrobia, Cyanobacteria, Gemmatimonadetes and Alphaproteobacteria, between the land use types forest and grassland were observed. At the genus level, significant differences were also recorded for the dominant genera Phenylobacter, Bacillus, Kribbella, Streptomyces, Agromyces, and Defluviicoccus. In addition, soil bacterial community structure showed significant differences between beech and spruce forest soils. The relative abundances of bacterial groups at different taxonomic levels correlated with soil pH, but little or no relationships to management type and other soil properties were found. Conclusions/Significance Soil bacterial community composition and diversity of the six analyzed management types showed significant differences between the land use types grassland

  5. Dominant Tree Species and Soil Type Affect the Fungal Community Structure in a Boreal Peatland Forest

    National Research Council Canada - National Science Library

    Sun, Hui; Terhonen, Eeva; Kovalchuk, Andriy; Tuovila, Hanna; Chen, Hongxin; Oghenekaro, Abbot O; Heinonsalo, Jussi; Kohler, Annegret; Kasanen, Risto; Vasander, Harri; Asiegbu, Fred O

    2016-01-01

    .... In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal...

  6. Rock type discrimination and structural analysis with LANDSAT and Seasat data: San Rafael swell, Utah

    Science.gov (United States)

    Stewart, H. E.; Blom, R.; Abrams, M.; Daily, M.

    1980-01-01

    Satellite synthetic aperture radar (SAR) images is evaluated in terms of its geologic applications. The benchmark to which the SAR images are compared is LANDSAT, used both for structural and lithologic interpretations.

  7. Structure of a novel c7-type three-heme cytochrome domain from a multidomain cytochrome c polymer

    OpenAIRE

    Pokkuluri, P. Raj; Londer, Yuri Y.; Duke, Norma E.C.; Erickson, Jill; Pessanha, Miguel; Salgueiro, Carlos A.; Schiffer, Marianne

    2004-01-01

    The structure of a novel c7-type cytochrome domain that has two bishistidine coordinated hemes and one heme with histidine, methionine coordination (where the sixth ligand is a methionine residue) was determined at 1.7 Å resolution. This domain is a representative of domains that form three polymers encoded by the Geobacter sulfurreducens genome. Two of these polymers consist of four and one protein of nine c7-type domains with a total of 12 and 27 hemes, respectively. Four individual domains...

  8. Type-II quantum-dot-in-nanowire structures with large oscillator strength for optical quantum gate applications

    DEFF Research Database (Denmark)

    Taherkhani, Masoomeh; Willatzen, Morten; Mørk, Jesper

    2017-01-01

    -I systems. To increase the oscillator strength, we propose a double quantum dot structure featuring a strongly localized exciton wave function and a corresponding fourfold relative enhancement of the oscillator strength, paving the way towards efficient optically controlled quantum gate applications......We present a numerical investigation of the exciton energy and oscillator strength in type-II nanowire quantum dots. For a single quantum dot, the poor overlap of the electron part and the weakly confined hole part of the excitonic wave function leads to a low oscillator strength compared to type...

  9. Determining workspace parameters for a new type of 6RSS parallel manipulator based on structural and geometric models

    Directory of Open Access Journals (Sweden)

    Milica Lucian

    2017-01-01

    Full Text Available Workspace geometric modelling of a new type of 6RSS parallel manipulator is described below. In the beginning, the researches undertaken in this area by other authors are highlighted and then a definition of this type of mechanisms is provided. The structural model of the 6RSS manipulator is briefly described. Inverse geometric model and translation subspace methods are used in order to determine the dimensions that define the workspace volume of the parallel manipulator. The reachable workspace is defined as a subset of the whole workspace in relation with the positions achieved by the characteristic point.

  10. The genetic structure of the A mating-type locus of Lentinula edodes.

    Science.gov (United States)

    Au, Chun Hang; Wong, Man Chun; Bao, Dapeng; Zhang, Meiyan; Song, Chunyan; Song, Wenhua; Law, Patrick Tik Wan; Kües, Ursula; Kwan, Hoi Shan

    2014-02-10

    The Shiitake mushroom, Lentinula edodes (Berk.) Pegler is a tetrapolar basidiomycete with two unlinked mating-type loci, commonly called the A and B loci. Identifying the mating-types in shiitake is important for enhancing the breeding and cultivation of this economically-important edible mushroom. Here, we identified the A mating-type locus from the first draft genome sequence of L. edodes and characterized multiple alleles from different monokaryotic strains. Two intron-length polymorphism markers were developed to facilitate rapid molecular determination of A mating-type. L. edodes sequences were compared with those of known tetrapolar and bipolar basidiomycete species. The A mating-type genes are conserved at the homeodomain region across the order Agaricales. However, we observed unique genomic organization of the locus in L. edodes which exhibits atypical gene order and multiple repetitive elements around its A locus. To our knowledge, this is the first known exception among Homobasidiomycetes, in which the mitochondrial intermediate peptidase (mip) gene is not closely linked to A locus. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Cytotoxic lanostane-type triterpenoids from the fruiting bodies of Ganoderma lucidum and their structure-activity relationships.

    Science.gov (United States)

    Chen, Shaodan; Li, Xiangmin; Yong, Tianqiao; Wang, Zhanggen; Su, Jiyan; Jiao, Chunwei; Xie, Yizhen; Yang, Burton B

    2017-02-07

    We conducted a study of Ganoderma lucidum metabolites and isolated 35 lanostane-type triterpenoids, including 5 new ganoderols (1-5). By spectroscopy, we compared the structures of these compounds with known related compounds in this group. All of the isolated compounds were assayed for their effect against the human breast carcinoma cell line MDA-MB-231 and hepatocellular carcinoma cell line HepG2. Corresponding three-dimensional quantitative structure-activity relationship (3D-QSAR) models were built and analyzed using Discovery Studio. These results provide further evidence for anti-cancer constituents within Ganoderma lucidum, and may provide a theoretical foundation for designing novel therapeutic compounds.

  12. Cost-benefit analysis of the construction of different flexible pavement structures considering the axle load and type of binder

    Directory of Open Access Journals (Sweden)

    Lucas Dotto Bueno

    2016-08-01

    Full Text Available The status of Brazilian highways reflects a deficient pavement performance when they are subjected to loadings imposed by heavy traffic. Current legislation, as enacted by Contran (National Traffic Council, has increased the axle weight limit for cargo vehicles by up to 10%. Therefore, the aim of this study was to determine a cost-benefit ratio by using different types of structures, asphalt binders and load intensities. Typical pavements were determined and then analyzed by the software AEMC (SisPav to obtain the horizontal tensile strain (εt values at the bottom of the asphalt concrete layer and, later, the NFATIGUE value. It was found that the increase in weight, within values covered by legislation, might result in a reduction of approximately 50% in the NFATIGUE value for the pavement structures analyzed. As for economic impact, the same weight increase caused a mean increase of 120% in the cost of repeated loading on pavement structures (R$ NFATIGUE-1. It was also observed that structures with more robust asphalt concrete layers can provide the best R$ NFATIGUE-1 ratios. The best results for granular materials were found with thinner layers, associated with a thicker coating. The benefits of modified binders were shown by the analyses of the best structural options: both the polymer-modified binder and the rubber asphalt binder offer significant structural and economic improvements to the structure.

  13. Effect of sintering temperature on structural property of X-type barium-zinc hexaferrites

    Science.gov (United States)

    Kagdi, Amrin; Solanki, Neha; Jotania, Rajshree B.

    2016-05-01

    X-type Barium-Zinc hexaferrite powder with chemical composition Ba2Zn2Fe28O46 has been prepared using citrate gel auto combustion technique. The combusted powder waspre-heated at 550 °C for 4 hours followed by final calcinations of 1100 °C and 1250 °C for 5 hoursrespectively. Prepared hexaferrite samples were characterizedusingdifferent instrumental techniques such as FTIR and XRD. XRD analysis of the sample calcined at 1250 °C revealed formation of mono phase of X-type hexaferrite; while the sample calcined at 1100 °C shows multiphases of M, W and X-type hexaferrites. FTIR spectra of both samples show stretching of metal-oxide bands.

  14. MIn(HAsO4)2 (M = K, Rb, Cs): three new hydrogenarsenates adopting two different structure types

    OpenAIRE

    Karolina Schwendtner; Uwe Kolitsch

    2017-01-01

    Potassium indium bis[hydrogen arsenate(V)], KIn(HAsO4)2, rubidium indium bis[hydrogen arsenate(V)], RbIn(HAsO4)2, and caesium indium bis[hydrogen arsenate(V)], CsIn(HAsO4)2, were grown under mild hydrothermal conditions (T = 493 K, 7–8 d). KIn(HAsO4)2 adopts the KSc(HAsO4)2 structure type (space group C2/c), while RbIn(HAsO4)2 and CsIn(HAsO4)2 crystallize in the space group R-3c and are the first arsenate representatives of the RbFe(HPO4)2 structure type. All three compounds have tetrahedral–...

  15. KInAs2O7, a new diarsenate with the TlInAs2O7 structure type

    Directory of Open Access Journals (Sweden)

    Karolina Schwendtner

    2017-09-01

    Full Text Available Potassium indium diarsenate(V was grown under mild hydrothermal conditions (T = 493 K, 7 d at a pH value of about 1. It adopts the TlInAs2O7 structure type (P-1, Z = 4 and is closely related to the KAlP2O7 (P21/c and RbAlAs2O7 (P-1 structure types. The framework topology of KInAs2O7 is built of two symmetrically non-equivalent As2O7 groups which share corners with InO6 octahedra. The K atoms are located in channels extending along [010].

  16. Structure design and motion simulation of the pin-cycloid gear planetary reducer with ring-plate-type

    Science.gov (United States)

    Duan, Hongjie; Li, Lijun; Tao, Junyi

    2017-06-01

    The pin-cycloid gear planetary reducer with ring-plate-type is a new type of reducers. It has high transmission ratio range and high efficiency. In this paper the working principle of pin-cycloid gear planetary reducer is discussed, and the structure of the reducer is designed. Especially for the complexity and the difficulty in modelling of the cycloid gear tooth profile, the parametric design module of cycloid gear is developed to solve the cycloid gear modelling problem through the second development of Solid Works. At last, the speed schemes of the input shaft and output shaft of the reducer are obtained by the motion simulation. Through the analysis of the simulation curves, the rationality of the structure design is proved, which provides a theoretical basis for the design and manufacture of the reducer.

  17. Spin-glass transition in Ni carbide single crystal nanoparticles with Ni3C − type structure

    Directory of Open Access Journals (Sweden)

    S. Fujieda

    2016-05-01

    Full Text Available Hexagonal shaped nanoparticles about 60 nm in size were successfully synthesized in tetraethylene glycol solution containing polyvinylpyrrolidone. By the analysis of the electron diffraction pattern, these were identified as a single crystal of Ni carbide with Ni3C − type structure. Their magnetization curve at 5 K was not completely saturated under a magnetic field of 5 T. The thermomagnetization curves after zero-field cooling and after field cooling exhibited the magnetic cooling effect at low temperatures. Furthermore, the 2nd order nonlinear term of AC magnetic susceptibility exhibited a negative divergence at about 17 K. It is concluded that Ni carbide single crystal nanoparticles with the Ni3C − type structure exhibit spin-glass transition at low temperatures.

  18. Crash-Induced Vibration and Safety Assessment of Breakaway-Type Post Structures Made of High Anticorrosion Steels

    Directory of Open Access Journals (Sweden)

    Sang-Youl Lee

    2016-01-01

    Full Text Available This study deals with car crash effects and passenger safety assessment of post structures with breakaway types using high performance steel materials. To disperse the impact force when a car crashes into a post, the post could be designed with a breakaway feature. In this study, we used a new high anticorrosion steel for the development of advanced breakaways. Based on the improved Cowper-Symonds model, specific physical properties to the high anticorrosion steel were determined. In particular, the complex mechanism of breakaways was studied using various parameters. The parametric studies are focused on the various effects of car crash on the structural performance and passenger safety of breakaway-type posts. The combined effects of using different steel materials on the dynamic behavers are also investigated.

  19. Structural consistency analysis of recombinant and wild-type human serum albumin

    Science.gov (United States)

    Cao, Hui-Ling; Sun, Li-Hua; Liu, Li; Li, Jian; Tang, Lin; Guo, Yun-Zhu; Mei, Qi-Bing; He, Jian-Hua; Yin, Da-Chuan

    2017-01-01

    Recombinant human serum albumin (rHSA) is potential alternatives for human serum albumin (HSA) which may ease severe shortage of HSA worldwide. In theory, rHSA and HSA are the same. Structure decides function. Therefore, the 3D structural consistency analysis of rHSA and HSA is outmost importance, which is the base of their function consistency. In this paper, the crystal structures of rHSA at resolution limit of 2.22 Å and HSA at 2.30 Å were determined by X-ray diffraction (XRD), which were deposited in the Protein Data Bank (PDB) with accession codes 4G03 (rHSA) and 4G04 (HSA). The differences between rHSA and HSA were systematically analyzed from the crystallization behavior, diffraction data and three-dimensional (3D) structure. The superimposed contrasted analysis indicated that rHSA and HSA achieved a structural similarity of 99% with an r.m.s. deviation of 0.397 Å for the corresponding overall Cα atoms. In addition, the number of α-helices in the rHSA or HSA molecule was verified to be 30. As a result, rHSA can potentially replace HSA. The study provides a theoretical and experimental basis for the clinical and additional applications of rHSA. Meanwhile, it is also a good example for applications of genetic engineering.

  20. Design of an Improved Type Rotary Inductive Coupling Structure for Rotatable Contactless Power Transfer System

    Directory of Open Access Journals (Sweden)

    Lee Jia-You

    2015-01-01

    Full Text Available This paper is aimed at analyzing the rotary inductive coupling structure of contactless rotary transformer. The main feature of the proposed rotatable contactless power transfer system is which winding is coaxial-interlayered for improving the magnetic coupling capability. There is no ferrite core used in the secondary-side of the rotary inductive coupling structure, this helps to ease the exerted force that is stress by the secondary-side on spindle. In order to verify the feasibility of the proposed contactless power transfer system for rotary applications, an inductive powered rotary machinery and the control system have been integrated. The experimental results show that the maximum power transfer efficiency of the proposed rotary inductive coupling structure is about 94.8%. The maximum output power received in the load end is 1030 W with transmission efficiency of 88%.

  1. Structure of Glycerol Dehydratase Reactivase: A New Type of Molecular Chaperone

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Der-Ing; Reiss, Lisa; Turner, Jr., Ivan; Dotson, Garry (Dupont)

    2010-03-08

    The function of glycerol dehydratase (GDH) reactivase is to remove damaged coenzyme B{sub 12} from GDH that has suffered mechanism-based inactivation. The structure of GDH reactivase from Klebsiella pneumoniae was determined at 2.4 {angstrom} resolution by the single isomorphous replacement with anomalous signal (SIR/AS) method. Each tetramer contains two elongated 63 kDa {alpha} subunits and two globular 14 kDa {beta} subunits. The {alpha} subunit contains structural features resembling both GroEL and Hsp70 groups of chaperones, and it appears chaperone like in its interactions with ATP. The fold of the {beta} subunit resembles that of the {beta} subunit of glycerol dehydratase, except that it lacks some coenzyme B12 binding elements. A hypothesis for the reactivation mechanism of reactivase is proposed based on these structural features.

  2. Structure of the C-type lectin carbohydrate recognition domain of human tetranectin

    DEFF Research Database (Denmark)

    Kastrup, J S; Nielsen, B B; Rasmussen, H

    1998-01-01

    Tetranectin (TN) is a C-type lectin involved in fibrinolysis, being the only endogenous ligand known to bind specifically to the kringle 4 domain of plasminogen. TN was originally isolated from plasma, but shows a wide tissue distribution. Furthermore, TN has been found in the extracellular matrix...

  3. Structural and mechanistic insights into ABC-type ECF transporters for vitamin uptake

    NARCIS (Netherlands)

    Dosz-Majsnerowska, Maria

    2014-01-01

    Dit proefschrift gaat over de relatie tussen de structuur en het mechanisme van ABC-type ECF transporters voor vitamines, uit de bacterie Lactococcus lactis. Energy-Coupling Factor (ECF) transporters vormen een subgroep van de ATP-binding cassette (ABC) transporters en zijn betrokken bij de opname

  4. Examining Culturally Structured Learning Environments with Different Types of Music-Linked Movement Opportunity

    Science.gov (United States)

    Cole, Juanita M.; Boykin, A. Wade

    2008-01-01

    This study describes two experiments that extended earlier work on the Afrocultural theme Movement Expression. The impact of various learning conditions characterized by different types of music-linked movement on story recall performance was examined. African American children were randomly assigned to a learning condition, presented a story, and…

  5. Lymphocyte activation receptors:new structural paradigms in group V of C-type animal lectins

    Czech Academy of Sciences Publication Activity Database

    Pavlíček, J.; Kavan, Daniel; Pompach, Petr; Novák, Petr; Lukšan, Ondřej; Bezouška, Karel

    2004-01-01

    Roč. 32, č. 6 (2004), s. 1124-1126 ISSN 0300-5127 R&D Projects: GA AV ČR IAA5020403 Institutional research plan: CEZ:AV0Z5020903 Keywords : lectin -type receptor * ligand identification * lymphocyte Subject RIV: EE - Microbiology, Virology Impact factor: 2.267, year: 2004

  6. Structure of Spa15, a type III secretion chaperone from Shigella flexneri with broad specificity

    NARCIS (Netherlands)

    Eerde, André van; Hamiaux, Cyril; Pérez, Javier; Parsot, Claude; Dijkstra, Bauke W.

    2004-01-01

    Type III secretion (TTS) systems are used by many Gram-negative pathogens to inject virulence proteins into the cells of their hosts. Several of these virulence effectors require TTS chaperones that maintain them in a secretion-competent state. Whereas most chaperones bind only one effector, Spa15

  7. Structure-cytotoxicity relationships of some helenanolide-type sesquiterpene lactones

    NARCIS (Netherlands)

    Beekman, AC; Woerdenbag, HJ; vanUden, W; Pras, N; Konings, AWT; Wikstrom, HV; Schmidt, TJ

    This study deals with the cytotoxicity of helenanolide-type (10 alpha-methylpseudoguaianolide) sesquiterpene lactones. We determined the influence of substitution patterns on the toxicity of 21 helenanolides to a cloned Ehrlich ascites tumor cell line, EN2. Within a series of helenalin esters, the

  8. The structure of galactic disks - Studying late-type spiral galaxies using SDSS

    NARCIS (Netherlands)

    Pohlen, M.; Trujillo, I.

    Using imaging data from the SDSS survey, we present the g' and r' radial stellar light distribution of a complete sample of similar to 90 face-on to intermediate inclined, nearby, late-type (Sb-Sdm) spiral galaxies. The surface brightness profiles are reliable (1s uncertainty less than 0.2 mag) down

  9. Structure and chromosomal localization of the human anti-mullerian hormone type II receptor gene

    NARCIS (Netherlands)

    J.A. Visser (Jenny); A. McLuskey; T. van Beers (T.); D.O. Weghuis (D. Olde); A.H.M. Geurts van Kessel (Ad); J.A. Grootegoed (Anton); A.P.N. Themmen (Axel)

    1995-01-01

    textabstractUsing the rat anti-müllerian hormone type II receptor (AMHRII) cDNA as a probe, two overlapping lambda phage clones containing the AMHRII gene were isolated from a human genomic library. Sequence analysis of the exons was performed and the exon/intron boundaries were determined. The

  10. A New Type of In-Pipe Inspection Minirobot with Adaptable Structure (IPMR-3

    Directory of Open Access Journals (Sweden)

    Andrei Pop

    2016-06-01

    Full Text Available Pipe damages and imperfections led to a start in researching ways of inspecting and maintaining the pipelines. An attractive solution is using mobile robots for this matter. This paper presents the development process of a wheeled in-pipe minirobot with adaptable structure called IPMR-3. IPMR-3has three articulated mechanisms placed at 120° angles around its central axis. The actuation is done with three DC motors. IPMR-3 can adapt its structure to pipe diameters ranged between 220 and 380 mm. The end of the paper presents the image capturing method, achieved with a C910 wireless video camera, and images from the testing process.

  11. Structural Dimensions, Fabrication, Materials, and Operational History for Types I and II Waste Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B.J.

    2000-08-16

    Radioactive waste is confined in 48 underground storage tanks at the Savannah River Site. The waste will eventually be processed and transferred to other site facilities for stabilization. Based on waste removal and processing schedules, many of the tanks, including those with flaws and/or defects, will be required to be in service for another 15 to 20 years. Until the waste is removed from storage, transferred, and processed, the materials and structures of the tanks must maintain a confinement function by providing a leak-tight barrier to the environment and by maintaining acceptable structural stability during design basis event which include loading from both normal service and abnormal conditions.

  12. Enhancement of structural and magnetic properties of M-type hexaferrite permanent magnet based on synthesis temperature

    Science.gov (United States)

    Anjum, Safia; Sehar, Fatima; Mustafa, Zeeshan; Awan, M. S.

    2018-01-01

    The main purpose of this research work is to develop the single domain magnetic particles of M-type barium hexaferrite (BaFe12O19) using oxide precursors employing conventional powder metallurgy technique. The phase formation and magnetic performance of the powders and magnets will be optimized by adjusting calcination and sintering temperatures. The synthesis of M-type barium hexaferrite was carried out in two sections. A series of four samples have been prepared by initial wet mixed powders calcined at different temperatures, i.e., 750, 850, 950 and 1050 °C. On the basis of structural analysis, the sample calcined at 950 °C has been selected and further divided into four parts to sintered them at 1100, 1150, 1200 and 1250 °C. The structural measurements depict the confirmation of M-type barium hexaferrite structure. SEM micrographs show the hexagonal-shaped grains. The abrupt decrease in coercivity for the sample sintered at 1250 °C has been seen which may be due to high sintering temperature, at which the particles have multi-domain properties.

  13. Land use types influenced avian assemblage structure in a forest-agriculture landscape in Ghana.

    Science.gov (United States)

    Deikumah, Justus Precious; Kwafo, Richard; Konadu, Vida Asieduwaa

    2017-11-01

    The conservation of biodiversity within tropical forest regions does not lie only in the maintenance of natural forest areas, but on conservation strategies directed toward agricultural land types within which they are embedded. This study investigated variations in bird assemblages of different functional groups of forest-dependent birds in three agricultural land types, relative to distance from the interior of 34 tropical forest patches of varying sizes. Point counts were used to sample birds at each study site visited. Data from counts were used to estimate species richness, species evenness, and Simpson's diversity of birds. Mean species richness, evenness, and diversity were modeled as responses and as a function of agricultural land type, distance from the forest interior and three site-scale vegetation covariates (density of large trees, fruiting trees, and patch size) using generalized linear mixed-effect models. Mean observed species richness of birds varied significantly within habitat types. Mean observed species richness was highest in forest interior sites while sites located in farm centers recorded the lowest mean species richness. Species richness of forest specialists was strongly influenced by the type of agricultural land use. Fallow lands, density of large trees, and patch size strongly positively influenced forest specialists. Insectivorous and frugivorous birds were more species-rich in fallow lands while monoculture plantations favored nectarivorous birds. Our results suggest that poor agricultural practices can lead to population declines of forest-dependent birds particularly specialist species. Conservation actions should include proper land use management that ensures heterogeneity through retention of native tree species on farms in tropical forest-agriculture landscapes.

  14. The structure of Serratia marcescens Lip, a membrane-bound component of the type VI secretion system

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Vincenzo A.; Shepherd, Sharon M.; English, Grant; Coulthurst, Sarah J.; Hunter, William N., E-mail: w.n.hunter@dundee.ac.uk [College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland (United Kingdom)

    2011-12-01

    The high-resolution crystal structure of S. marcescens Lip reveals a new member of the transthyretin family of proteins. Lip, a core component of the type VI secretion apparatus, is localized to the outer membrane and is positioned to interact with other proteins forming this complex system. Lip is a membrane-bound lipoprotein and a core component of the type VI secretion system found in Gram-negative bacteria. The structure of a Lip construct (residues 29–176) from Serratia marcescens (SmLip) has been determined at 1.92 Å resolution. Experimental phases were derived using a single-wavelength anomalous dispersion approach on a sample cocrystallized with iodide. The membrane localization of the native protein was confirmed. The structure is that of the globular domain lacking only the lipoprotein signal peptide and the lipidated N-terminus of the mature protein. The protein fold is dominated by an eight-stranded β-sandwich and identifies SmLip as a new member of the transthyretin family of proteins. Transthyretin and the only other member of the family fold, 5-hydroxyisourate hydrolase, form homotetramers important for their function. The asymmetric unit of SmLip is a tetramer with 222 symmetry, but the assembly is distinct from that previously noted for the transthyretin protein family. However, structural comparisons and bacterial two-hybrid data suggest that the SmLip tetramer is not relevant to its role as a core component of the type VI secretion system, but rather reflects a propensity for SmLip to participate in protein–protein interactions. A relatively low level of sequence conservation amongst Lip homologues is noted and is restricted to parts of the structure that might be involved in interactions with physiological partners.

  15. Relationship between copper, glycopeptide, and macrolide resistance among Enterococcus faecium strains isolated from pigs in Denmark between 1997 and 2003

    DEFF Research Database (Denmark)

    Hasman, Henrik; Aarestrup, Frank Møller

    2005-01-01

    A significant relationship between copper resistance (tcrB), glycopeptide resistance (Tn1546), and macrolide resistance [erm(B)] in Enterococcus faecium isolated from pigs was found. The tcrB gene was located closely upstream of the Tn1546 element. However, the continued use of copper sulfate has...

  16. Mechanism of Bacterial Cell-Surface Attachment Revealed by the Structure of Cellulosomal Type II Cohesin-dockerin Complex

    Energy Technology Data Exchange (ETDEWEB)

    Adams,J.; Pal, G.; Jia, Z.; Smith, S.

    2006-01-01

    Bacterial cell-surface attachment of macromolecular complexes maintains the microorganism in close proximity to extracellular substrates and allows for optimal uptake of hydrolytic byproducts. The cellulosome is a large multienzyme complex used by many anaerobic bacteria for the efficient degradation of plant cell-wall polysaccharides. The mechanism of cellulosome retention to the bacterial cell surface involves a calcium-mediated protein-protein interaction between the dockerin (Doc) module from the cellulosomal scaffold and a cohesin (Coh) module of cell-surface proteins located within the proteoglycan layer. Here, we report the structure of an ultra-high-affinity (K{sub a} = 1.44 x 10{sup 10} M{sup 1-}) complex between type II Doc, together with its neighboring X module from the cellulosome scaffold of Clostridium thermocellum, and a type II Coh module associated with the bacterial cell surface. Identification of X module-Doc and X module-Coh contacts reveal roles for the X module in Doc stability and enhanced Coh recognition. This extremely tight interaction involves one face of the Coh and both helices of the Doc and comprises significant hydrophobic character and a complementary extensive hydrogen-bond network. This structure represents a unique mechanism for cell-surface attachment in anaerobic bacteria and provides a rationale for discriminating between type I and type II Coh modules.

  17. Vegetation types, dominant compositions, woody plant diversity and stand structure in Trishna Wildlife Sanctuary of Northeast India.

    Science.gov (United States)

    Majumdar, Koushik; Datta, B K

    2015-03-01

    Present study was carried out to assess the vegetation types, diversity and phytosociological status of woody plants in Trishna Wildlife Sanctuary of Tripura, Northeast India. Vegetation data was derived by 25 line transects (10 m wide and 500 m length, each 0.5 ha size). All woody species at >10 cm gbh (Girth at Breast Height) within each plots were measured and counted. A total of six forest types were classified by cluster analysis using Importance Value Index (IVI) of 289 woody species. Species diversity, forest structure and woody community associations were evaluated and discussed. One way ANOVA revealed significant differences in all species diversity measures and stand structure along the forest types. Distribution of stem density at ten different gbh classes showed reverse J-shaped curves. Population status of woody plants was also examined through grouping of all individuals into four population age stages viz. sapling ( or = 30 - 120 - 210 cm gbh) and old (> or =210 cm). To observe dominant composition and species population trend, IVI of top ten dominant species from all forest types were tabulated. The present study suggested that Trishna Wildlife Sanctuary is an important habitat in Tripura from floristic point of view and it should be conserved on priority basis for remaining wildlife endurances and monitor for forest livelihoods products for sustainable biodiversity conservation in this region.

  18. Investigation into possible geometrical configurations for scissor-type deployable structures using expandable bars

    DEFF Research Database (Denmark)

    Lee, Daniel Sang-Hoon; Jia, Wenwen; Cai, Jianguo

    2015-01-01

    The current paper describes a spin-off investigation from the initially published international research project [1] [2] , which is looking into the design and development of single-meridian grid deployable structure. As a part of the collaborative international project between South Korea (Project...

  19. Crystal structure of a copper-transporting PIB-type ATPase

    DEFF Research Database (Denmark)

    Gourdon, Pontus; Liu, Xiang-Yu; Skjørringe, Tina

    2011-01-01

    copper entry point at the intracellular interface. Comparisons to Ca(2+)-ATPase suggest an ATPase-coupled copper release mechanism from the binding sites in the membrane via an extracellular exit site. The structure also provides a framework to analyse missense mutations in the human ATP7A and ATP7B...... proteins associated with Menkes' and Wilson's diseases....

  20. Structural, magnetic, and Mössbauer spectroscopy of Cu substituted M-type hexaferrites

    Energy Technology Data Exchange (ETDEWEB)

    Awadallah, Ahmad, E-mail: ahmadmoh@yahoo.co [Physics Department, The University of Jordan, Amman 11942 (Jordan); Mahmood, Sami H., E-mail: s.mahmood@ju.edu.jo [Physics Department, The University of Jordan, Amman 11942 (Jordan); Maswadeh, Yazan, E-mail: nawabra251@gmail.com [Physics Department, The University of Jordan, Amman 11942 (Jordan); Bsoul, Ibrahim, E-mail: ibrahimbsoul@yahoo.com [Physics Department, Al al-Bayt University, Mafraq 13040 (Jordan); Awawdeh, Mufeed, E-mail: amufeed@yu.edu.jo [Physics Department, Yarmouk University, Irbid 21163 (Jordan); Mohaidat, Qassem I., E-mail: q.muhaidat@yu.edu.jo [Physics Department, Yarmouk University, Irbid 21163 (Jordan); Juwhari, Hassan, E-mail: h.juwhari@ju.edu.jo [Physics Department, The University of Jordan, Amman 11942 (Jordan)

    2016-02-15

    Highlights: • Single BaM hexaferrite structural phases with Cu substations were prepared. • The magnetocrystalline anisotropy decreased with Cu substitution. • The coercivity was significantly modified while the magnetization remained high. • Hexaferrites with 0.2–0.4 Cu possess properties suitable for magnetic recording. • Ionic distributions from structural refinement agreed with Mössbauer spectroscopy. - Abstract: BaFe{sub 12−x}Cu{sub x}O{sub 19} hexaferrites were prepared using ball milling and sintering at 1100 °C. Refinement of the X-ray diffraction patterns was carried out to determine the structural parameters and the ionic distribution over the crystallographic sites. The preferential site occupation and valence state of Cu was consistent with the results obtained from the analysis of Mössbauer spectra. Further, the magnetic parameters of the samples were discussed in light of the structural and Mössbauer analyses. The magnetic phase transition temperature was found to decrease with the level of Cu substitution, in accordance with the reduction of the superexchange interactions. Further, the magnetic softening of the hexaferrite and the significant reduction in magnetocrystalline anisotropy with Cu substitution was consistent with the ionic distribution in the lattice. This study clearly demonstrated the feasibility of using a simple method to fabricate hexaferrites with a modified coercivity, while maintain the saturation magnetization high enough for practical applications.

  1. New insights into structure and function of the different types of fatty acid-binding protein

    NARCIS (Netherlands)

    Zimmerman, Augusta Wilhelmina

    2002-01-01

    Fatty acid binding proteins (FABPs) are small cytosolic proteins with virtually identical backbone structures that facilitate the solubility and intracellular transport of fatty acids. They may also modulate the effect of fatty acids on various metabolic enzymes and receptors and on cellular

  2. Structure and Composition of Protein Bodies from Wild-Type and High-Lysine Barley Endosperm

    DEFF Research Database (Denmark)

    Ingversen, J.

    1975-01-01

    with a granular component. Particles with the same structure were present in the protein body preparation from the mutant, where, however, the granular component was the most prominent. Amino-acid composition and SDS-polyacrylamide gel electrophoresis of the proteins from the protein body preparation revealed...

  3. STRUCTURAL PERFORMANCE OF TWO TYPES OF WALL SLAB CONNECTION UNDER OUT-OF-PLANE LATERAL CYCLIC LOADING

    Directory of Open Access Journals (Sweden)

    AHMED ABDULRAZZAQ NASSER AL-AGHBARI

    2012-04-01

    Full Text Available Currently, most of the high-rise buildings in Malaysia are constructed using tunnel form system. However, this type of structural system is still questionable of its safety under ground motion. Thus, the main objective of this study is to test and compare the structural performance of two types of wall-slab connection namely cross and anchorage bracings under reversible quasi-static cyclic loading. Two identical sub-assemblage of wall-slab connections are designed, constructed and tested in heavy structural laboratory. A load actuator together with load cell was positioned horizontally at the upper part of the wall for applying the lateral cyclic load. The experimental result shows that the anchorage bracing connection has higher strength, higher ductility, better energy absorption and less structural damage as compared to cross-bracing connections. Based on this experiment, the ductility of anchorage bracing connection is m=6 which satisfies the requirement of ductility for seismic code of practice. Anchorage bracing connection can resist earthquake loading better than cross-bracing connections. Therefore, it is recommended to the construction industry to adopt this kind of design together with the detailing which consists of double layer of wire fabric at the connections. As a conclusion, the anchorage bracing connection has better seismic performance as compared to cross-bracing connection under lateral cyclic loading.

  4. Designing Air-Stable O3-Type Cathode Materials by Combined Structure Modulation for Na-Ion Batteries.

    Science.gov (United States)

    Yao, Hu-Rong; Wang, Peng-Fei; Gong, Yue; Zhang, Jienan; Yu, Xiqian; Gu, Lin; OuYang, Chuying; Yin, Ya-Xia; Hu, Enyuan; Yang, Xiao-Qing; Stavitski, Eli; Guo, Yu-Guo; Wan, Li-Jun

    2017-06-28

    As promising high-capacity cathode materials for Na-ion batteries, O3-type Na-based metal oxides always suffer from their poor air stability originating from the spontaneous extraction of Na and oxidation of transition metals when exposed to air. Herein, a combined structure modulation is proposed to tackle concurrently the two handicaps via reducing Na layers spacing and simultaneously increasing valence state of transition metals. Guided by density functional theory calculations, we demonstrate such a modulation can be subtly realized through cosubstitution of one kind of heteroatom with comparable electronegativity and another one with substantially different Fermi level, by adjusting the structure of NaNi0.5Mn0.5O2 via Cu/Ti codoping. The as-obtained NaNi0.45Cu0.05Mn0.4Ti0.1O2 exhibits an increase of 20 times in stable air-exposure period and 9 times in capacity retention after 500 cycles, and even retains its structure and capacity after being soaked in water. Such a simple and effective structure modulation reveals a new avenue for high-performance O3-type cathodes and pushes the large-scale industrialization of Na-ion batteries a decisive step forward.

  5. Synthesis, crystal structure and charge-distribution validation of β-Na4Cu(MoO43 adopting the alluadite structure-type

    Directory of Open Access Journals (Sweden)

    Wassim Dridi

    2016-08-01

    Full Text Available Single crystals of a new variety of tetrasodium copper(II tris[molybdate(VI], Na4Cu(MoO43, have been synthesized by solid-state reactions and characterized by single-crystal X-ray diffraction. This alluaudite structure-type is characterized by the presence of infinite layers of composition (Cu/Na2Mo3O14 parallel to the (100 plane, which are linked by MoO4 tetrahedra, forming a three-dimensional framework containing two types of hexagonal channels in which Na+ cations reside. The Cu2+ and Na2+ cations are located at the same general site with occupancies of 0.5. All atoms are on general positions except for one Mo, two Na (site symmetry 2 and another Na (site symmetry -1 atom. One O atom is split into two separate positions with occupancies of 0.5. The title compound is isotypic with Na5Sc(MoO44 and Na3In2As3O12. The structure model is supported by bond-valence-sum (BVS and charge-distribution CHARDI methods. β-Na4Cu(MoO43 is compared and discussed with the K4Cu(MoO43 and α-Na4Cu(MoO43 structures.

  6. In situ environment rather than substrate type dictates microbial community structure of biofilms in a cold seep system

    KAUST Repository

    Lee, O.O.

    2014-01-08

    Using microscopic and molecular techniques combined with computational analysis, this study examined the structure and composition of microbial communities in biofilms that formed on different artificial substrates in a brine pool and on a seep vent of a cold seep in the Red Sea to test our hypothesis that initiation of the biofilm formation and spreading mode of microbial structures differs between the cold seep and the other aquatic environments. Biofilms on different substrates at two deployment sites differed morphologically, with the vent biofilms having higher microbial abundance and better structural features than the pool biofilms. Microbes in the pool biofilms were more taxonomically diverse and mainly composed of various sulfate-reducing bacteria whereas the vent biofilms were exclusively dominated by sulfur-oxidizing Thiomicrospira. These results suggest that the redox environments at the deployment sites might have exerted a strong selection on microbes in the biofilms at two sites whereas the types of substrates had limited effects on the biofilm development.

  7. Landscape structure and diseases profile: associating land use type composition with disease distribution.

    Science.gov (United States)

    Votsi, Nefta-Eleftheria P; Mazaris, Antonios D; Kallimanis, Athanasios S; Drakou, Evangelia G; Pantis, John D

    2014-04-01

    Human health and well-being presuppose environmental quality. Several studies have documented the indicative role of land use types in environmental quality. However, the exact role of land use composition on disease distribution has remained scientifically vague. We assessed the congruence of diseases' distribution with land use composition, focusing on high environmental quality areas, defined as tranquil areas with view to indicating places offering well-being. Landscape composition is linked to the presence of diseases across 51 prefectures of Greece. Agricultural and natural land use types proved to be the main drivers of disease distribution. Tranquility demonstrated a strong negative correlation with population density, thus could be considered as a quantitative spatial index of life-quality. We concluded that the landscape context affects the dominance of diseases' patterns. Special emphasis should be put on the role of tranquil areas in human health and the relative environmental health policies.

  8. Structural requirements of the major protective antibody to Haemophilus influenzae type b

    DEFF Research Database (Denmark)

    Hougs, L; Juul, L; Svejgaard, A

    1999-01-01

    Protective antibodies to the important childhood pathogen Haemophilus influenzae type b (Hib) are directed against the capsular polysaccharide (HibCP). Most of the antibody is encoded by a well-defined set of ("canonical") immunoglobulin genes, including the Vkappa A2 gene, and expresses an idiot......Protective antibodies to the important childhood pathogen Haemophilus influenzae type b (Hib) are directed against the capsular polysaccharide (HibCP). Most of the antibody is encoded by a well-defined set of ("canonical") immunoglobulin genes, including the Vkappa A2 gene, and expresses...... an idiotypic marker (HibId-1). In comparison to noncanonical antibodies, the canonical antibody is generally of higher avidity, shows higher levels of in vitro bactericidal activity, and is more protective in infant rats. Using site-directed mutagenesis, we here characterize canonical HibCP antibodies...

  9. Hencky-type discrete model for pantographic structures: numerical comparison with second gradient continuum models

    Science.gov (United States)

    Turco, Emilio; dell'Isola, Francesco; Cazzani, Antonio; Rizzi, Nicola Luigi

    2016-08-01

    Hencky (Über die angenäherte Lösung von Stabilitätsproblemen im Raum mittels der elastischen Gelenkkette. Ph.D. thesis, Engelmann, 1921) proposed a discrete model for elasticae by introducing rigid bars and rotational springs. Hencky (Proc R Soc Lond A Math Phys Eng Sci 472(2185), 2016) approach has been introduced to heuristically motivate the need of second gradient continua. Here, we present a novel numerical code implementing directly the discrete Hencky-type model which is robust enough to solve the problem of the determination of equilibrium configurations in the large deformation and displacement regimes. We apply this model to study some potentially applicable problems, and we compare its performances with those of the second gradient continuum model. The numerical evidence presented supports the conjecture that Hencky-type converges to second gradient model.

  10. Structure and operation of the DNA-translocating type I DNA restriction enzymes

    OpenAIRE

    Kennaway, Christopher K.; Taylor, James E.; Song, Chun Feng; Potrzebowski, Wojciech; Nicholson, William; White, John H.; Swiderska, Anna; Obarska-Kosinska, Agnieszka; Callow, Philip; Cooper, Laurie P.; Roberts, Gareth A.; Artero, Jean-Baptiste; Bujnicki, Janusz M.; Trinick, John; Kneale, G. Geoff

    2012-01-01

    Type I DNA restriction/modification (RM) enzymes are molecular machines found in the majority of bacterial species. Their early discovery paved the way for the development of genetic engineering. They control (restrict) the influx of foreign DNA via horizontal gene transfer into the bacterium while maintaining sequence-specific methylation (modification) of host DNA. The endonuclease reaction of these enzymes on unmethylated DNA is preceded by bidirectional translocation of thousands of base ...

  11. Haemophilus influenzae type b carriage and novel bacterial population structure among children in urban Kathmandu, Nepal.

    Science.gov (United States)

    Williams, E J; Lewis, J; John, T; Hoe, J C; Yu, L; Dongol, S; Kelly, D F; Griffiths, D T; Shah, A; Limbu, B; Pradhan, R; Mawas, F; Shrestha, S; Thorson, S; Werno, A M; Murdoch, D R; Adhikari, N; Pollard, A J

    2011-04-01

    Haemophilus influenzae type b (Hib) is a major cause of invasive bacterial infection in children that can be prevented by a vaccine, but there is still uncertainty about its relative importance in Asia. This study investigated the age-specific prevalence of Hib carriage and its molecular epidemiology in carriage and disease in Nepal. Oropharyngeal swabs were collected from children in Kathmandu, Nepal, from 3 different settings: a hospital outpatient department (OPD), schools, and children's homes. Hib was isolated using Hib antiserum agar plates, and serotyping was performed with latex agglutination. Hib isolates from children with invasive disease were obtained during active microbiological surveillance at Patan Hospital, Kathmandu, Nepal. Genotyping of disease and carriage isolates was undertaken using multilocus sequence typing (MLST). Swabs were taken from 2,195 children, including 1,311 children at an OPD, 647 children attending schools, and 237 children in homes. Overall, Hib was identified in 5.0% (110/2,195; 95% confidence interval [95% CI], 3.9% to 6.4%). MLST was performed on 108 Hib isolates from children carrying Hib isolates and 15 isolates from children with invasive disease. Thirty-one sequence types (STs) were identified, and 20 of these were novel STs. The most common ST isolates were sequence type 6 (ST6) and the novel ST722. There was marked heterogeneity among the STs from children with disease and children carrying Hib. STs identified from invasive infections were those commonly identified in carriage. This study provides evidence of Hib carriage among children in urban Nepal with genetically diverse strains prior to introduction of universal vaccination. The Hib carriage rate in Nepal was similar to the rates observed in other populations with documented high disease rates prior to vaccination, supporting implementation of Hib vaccine in Nepal in 2009.

  12. Structural Changes of Thyroid Gland in Victims of Chernobyl Disaster with Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    I.M. Muravyova

    2014-07-01

    Full Text Available According to the objective of the study, we have carried out a research of clinical relationships between diabetes mellitus (DM type 2 and nonmalignant thyroid disease in victims of Chernobyl disaster in remote post-accident period (148 persons and in control group (38 persons. We have obtained data on the nature and incidence of thyroid organic pathology. The incidence of thyroid organic pathology in patients with DM type 2, who are victims of Chernobyl disaster (58.3 ± 6.3 %, is statistically significant (p < 0.05 higher than in control group (43.1 ± 3.9 %. Dominating pathology in patients with type 2 DM, who are victims of Chernobyl disaster, is nodular euthyroid goiter, the incidence of which (26.7 ± 5.7 % in 3.3 time higher (p < 0.01 than in control group (8.1 ± 2.2 %, and depends on sex, age and duration of underlying disease.

  13. Simulation of heat transfer in intricately-configured polymer composite structures of instrumented container type

    Directory of Open Access Journals (Sweden)

    Slitkov Mikhail N.

    2017-01-01

    Full Text Available Method of mathematical simulation of heat transfer processes in polymer composite (PC products with intricate configuration, being an alternative of using up-to-date commercial software complexes has been developed. On the example of PC container with instrumentation and fiberglass electric heaters located in it, a mathematical model describing unsteady temperature field (a system of nonlinear differential heat balance equations for each element has been formulated. Features of heat transfer between elements (heaters, instrumentation, enclosing structures were taken into account. The verification of the method was conducted by comparing of theoretical temperature distributions with results of measurements in experiments with simplified variant of the structure. The developed method is effective, in particular, for such PC products as containers, modules, bunkers and vessels. It allows us to specify optimum operation modes for heating elements, operational parameters for conditioners and funs, heat insulation characteristics for providing a given level of air temperature inside objects in winter and summer service periods.

  14. Morphology, genome sequence, and structural proteome of type phage P335 from Lactococcus lactis

    DEFF Research Database (Denmark)

    Labrie, Simon J.; Josephsen, Jytte; Neve, Horst

    2008-01-01

    for a shorter tail and a different collar/whisker structure. Its 33,613-bp double-stranded DNA genome had 50 open reading frames. Putative functions were assigned to 29 of them. Unlike other sequenced genomes from lactococcal phages belonging to this species, P335 did not have a lysogeny module. However, it did...... carry a dUTPase gene, the most conserved gene among this phage species. Comparative genomic analyses revealed a high level of identity between the morphogenesis modules of the phages P335, ul36, TP901-1, and Tuc2009 and two putative prophages of L. lactis SK11. Differences were noted in genes coding...... for receptor-binding proteins, in agreement with their distinct host ranges. Sixteen structural proteins of phage P335 were identified by liquid chromatography-tandem mass spectrometry. A 2.8-kb insertion was recognized between the putative genes coding for the activator of late transcription (Alt...

  15. Einstein equations and conformal structure: Existence of Anti-de Sitter-type space-times

    Science.gov (United States)

    Friedrich, Helmut

    1995-10-01

    We discuss Einstein's equations in the context of normal conformal Cartan connections, derive a new conformal representation of the equations, and express the equations in a conformally invariant gauge. The resulting formulation of the equations is used to show the existence of asymptotically simple solutions to Einstein's equations with a positive cosmological constant. The solutions are characterized by Cauchy data on a space-like slice and by the intrinsic conformal structure on the conformal boundary at space-like and null infinity.

  16. From Proteomics to Structural Studies of Cytosolic/Mitochondrial-Type Thioredoxin Systems in Barley Seeds

    DEFF Research Database (Denmark)

    Shahpiri, Azar; Svensson, Birte; Finnie, Christine

    2009-01-01

    Thioredoxins (Trx) are ubiquitous proteins that participate in thiol disulfide reactions via two active site cysteine residues, allowing Trx to reduce disulfide bonds in target proteins. Recent progress in proteome analysis has resulted in identification of a wide range of potential target protei...... systems in cereal seeds and summarizes the current knowledge of the barley system including recent data on function, regulation, interactions, and structure. Directions for future research are discussed....

  17. Structural and magnetic properties in Heusler-type ferromagnet/antiferromagnet bilayers

    Science.gov (United States)

    Fukatani, N.; Inagaki, K.; Miyawaki, T.; Ueda, K.; Asano, H.

    2013-05-01

    The structure and magnetic properties of Heusler ferromagnet/antiferromagnet (FM/AFM) bilayers were investigated. Structural characterization revealed that Fe2CrSi/Ru2MnGe bilayers were epitaxially grown with an L21 ordered structure when the Ru2MnGe growth temperature was 573 K. The magnetization curve indicates that exchange bias occurs in the Fe2CrSi/Ru2MnGe bilayers at 77 K. The appearance of an exchange-anisotropy field Hex depends on the growth of Ru2MnGe layer, indicating that the exchange bias originates from the epitaxial Fe2CrSi/Ru2MnGe interface. The exchange anisotropy energy Jk of the Fe2CrSi/Ru2MnGe and Co2MnGe/Ru2MnGe bilayer systems appears to follow a Heisenberg-like exchange coupling model. This suggests that the Cr and Mn interface atoms in the FM layers play significant roles in exchange coupling in the Fe2CrSi/Ru2MnGe and Co2MnGe/Ru2MnGe bilayer systems, respectively.

  18. Isolated rat alveolar type II cells protrude intracellular lamellar bodies by forming bubble-like structures during surfactant secretion.

    Science.gov (United States)

    Ogasawara, Rie; Yoshida, Yasuo; Tohyama, Koujiro; Satoh, Yoh-ichi; Suwabe, Akira

    2009-02-01

    Pulmonary surfactant is synthesized and secreted by pulmonary alveolar type II epithelial cells (type II cells). It passes through the alveolar lining fluid and adsorbs to the air-liquid interface. The process from secretion to adsorption is not yet entirely understood. To acquire a detailed understanding of this process, we used multiple observations of type II cells isolated from rat lungs under electron microscopy (EM) and confocal laser scanning microscopy (CLSM). Transmission EM observation demonstrated a loosening process of the intracellular lamellar bodies from the inside to the outside of the cell. Scanning EM observation revealed bubble-like protrusions from the cell surface, and differential interference contrast microscopy illustrated the protrusions expanding with time. CLSM observation with FM 1-43, a fluorescent membrane probe, revealed that the bubble-like protrusions were composed of phospholipids. Thus, we have demonstrated that isolated rat type II cells protrude intracellular lamellar bodies by forming bubble-like structures, possibly enabling them to adsorb to the air-liquid interface directly. These observations suggest a new mechanism for surfactant secretion from type II cells.

  19. Layered hydride CaNiGeH with a ZrCuSiAs-type structure: crystal structure, chemical bonding, and magnetism induced by Mn doping.

    Science.gov (United States)

    Liu, Xiaofeng; Matsuishi, Satoru; Fujitsu, Satoru; Ishigaki, Toru; Kamiyama, Takashi; Hosono, Hideo

    2012-07-18

    Stimulated by the discovery of the iron oxypnictide superconductor with ZrCuSiAs-type structure in 2008, extensive exploration of its isostructural and isoelectronic compounds has started. These compounds, including oxides, fluorides, and hydrides, can all be simply recognized as valence compounds for which the octet rule is valid. We report herein the first example of a ZrCuSiAs-type hydride, CaNiGeH, which violates the octet rule. This hydride was synthesized by hydrogenation of the CeFeSi-type compound CaNiGe under pressurized hydrogen. Powder diffraction and theoretical simulation confirm that H enters into the interstitial position of the Ca(4) tetrahedron, leading to notable anisotropic expansion of the unit cell along the c axis. Density functional theory calculations indicate the modification of the chemical bonding and formation of ionic Ca-H bond as a result of hydrogen insertion. Furthermore, CaNiGeH shows Pauli paramagnetism and metallic conduction similar to that of CaNiGe, but its carrier type changes to hole and the carrier density is drastically reduced as compared to CaNiGe. Mn-doping at the Ni site introduces magnetism to both the parent compound and the hydride. The measurement demonstrates that hydrogenation of CaNi(1-x)Mn(x)Ge reduces ferromagnetic ordering of Mn ions and induces huge magnetic hysteresis, whereas the spin glass state observed for the parent compound is preserved in the hydride. The hydrogenation-induced changes in the electric and magnetic properties are interpreted in terms of development of two-dimensionality in crystal structure as well as electronic state.

  20. FR-type radio sources in COSMOS: relation of radio structure to size, accretion modes and large-scale environment

    Science.gov (United States)

    Vardoulaki, Eleni; Faustino Jimenez Andrade, Eric; Delvecchio, Ivan; Karim, Alexander; Smolčić, Vernesa; Magnelli, Benjamin; Bertoldi, Frank; Schinnener, Eva; Sargent, Mark; Finoguenov, Alexis; VLA COSMOS Team

    2018-01-01

    The radio sources associated with active galactic nuclei (AGN) can exhibit a variety of radio structures, from simple to more complex, giving rise to a variety of classification schemes. The question which still remains open, given deeper surveys revealing new populations of radio sources, is whether this plethora of radio structures can be attributed to the physical properties of the host or to the environment. Here we present an analysis on the radio structure of radio-selected AGN from the VLA-COSMOS Large Project at 3 GHz (JVLA-COSMOS; Smolčić et al.) in relation to: 1) their linear projected size, 2) the Eddington ratio, and 3) the environment their hosts lie within. We classify these as FRI (jet-like) and FRII (lobe-like) based on the FR-type classification scheme, and compare them to a sample of jet-less radio AGN in JVLA-COSMOS. We measure their linear projected sizes using a semi-automatic machine learning technique. Their Eddington ratios are calculated from X-ray data available for COSMOS. As environmental probes we take the X-ray groups (hundreds kpc) and the density fields (~Mpc-scale) in COSMOS. We find that FRII radio sources are on average larger than FRIs, which agrees with literature. But contrary to past studies, we find no dichotomy in FR objects in JVLA-COSMOS given their Eddington ratios, as on average they exhibit similar values. Furthermore our results show that the large-scale environment does not explain the observed dichotomy in lobe- and jet-like FR-type objects as both types are found on similar environments, but it does affect the shape of the radio structure introducing bents for objects closer to the centre of an X-ray group.

  1. Impact of type 2 diabetes and the metabolic syndrome on myocardial structure and microvasculature of men with coronary artery disease

    Directory of Open Access Journals (Sweden)

    Yii Michael

    2011-09-01

    Full Text Available Abstract Background Type 2 diabetes and the metabolic syndrome are associated with impaired diastolic function and increased heart failure risk. Animal models and autopsy studies of diabetic patients implicate myocardial fibrosis, cardiomyocyte hypertrophy, altered myocardial microvascular structure and advanced glycation end-products (AGEs in the pathogenesis of diabetic cardiomyopathy. We investigated whether type 2 diabetes and the metabolic syndrome are associated with altered myocardial structure, microvasculature, and expression of AGEs and receptor for AGEs (RAGE in men with coronary artery disease. Methods We performed histological analysis of left ventricular biopsies from 13 control, 10 diabetic and 23 metabolic syndrome men undergoing coronary artery bypass graft surgery who did not have heart failure or atrial fibrillation, had not received loop diuretic therapy, and did not have evidence of previous myocardial infarction. Results All three patient groups had similar extent of coronary artery disease and clinical characteristics, apart from differences in metabolic parameters. Diabetic and metabolic syndrome patients had higher pulmonary capillary wedge pressure than controls, and diabetic patients had reduced mitral diastolic peak velocity of the septal mitral annulus (E', consistent with impaired diastolic function. Neither diabetic nor metabolic syndrome patients had increased myocardial interstitial fibrosis (picrosirius red, or increased immunostaining for collagen I and III, the AGE Nε-(carboxymethyllysine, or RAGE. Cardiomyocyte width, capillary length density, diffusion radius, and arteriolar dimensions did not differ between the three patient groups, whereas diabetic and metabolic syndrome patients had reduced perivascular fibrosis. Conclusions Impaired diastolic function of type 2 diabetic and metabolic syndrome patients was not dependent on increased myocardial fibrosis, cardiomyocyte hypertrophy, alteration of the

  2. Community structure of skipper butterflies (Lepidoptera, Hesperiidae along elevational gradients in Brazilian Atlantic forest reflects vegetation type rather than altitude.

    Directory of Open Access Journals (Sweden)

    Eduardo Carneiro

    Full Text Available Species turnover across elevational gradients has matured into an important paradigm of community ecology. Here, we tested whether ecological and phylogenetic structure of skipper butterfly assemblages is more strongly structured according to altitude or vegetation type along three elevation gradients of moderate extent in Serra do Mar, Southern Brazil. Skippers were surveyed along three different mountain transects, and data on altitude and vegetation type of every collection site were recorded. NMDS ordination plots were used to assess community turnover and the influence of phylogenetic distance between species on apparent community patterns. Ordinations based on ecological similarity (Bray-Curtis index were compared to those based on phylogenetic distance measures (MPD and MNTD derived from a supertree. In the absence of a well-resolved phylogeny, various branch length transformation methods were applied together with four different null models, aiming to assess if results were confounded by low-resolution trees. Species composition as well as phylogenetic community structure of skipper butterflies were more prominently related to vegetation type instead of altitude per se. Phylogenetic distances reflected spatial community patterns less clearly than species composition, but revealed a more distinct fauna of monocot feeders associated with grassland habitats, implying that historical factors have played a fundamental role in shaping species composition across elevation gradients. Phylogenetic structure of community turned out to be a relevant additional tool which was even superior to identify faunal contrasts between forest and grassland habitats related to deep evolutionary splits. Since endemic skippers tend to occur in grassland habitats in the Serra do Mar, inclusion of phylogenetic diversity may also be important for conservation decisions.

  3. Nanometric solid solutions of the fluorite and perovskite type crystal structures: Synthesis and properties

    Directory of Open Access Journals (Sweden)

    Snežana Bošković

    2012-09-01

    Full Text Available In this paper a short review of our results on the synthesis of nanosized CeO2, CaMnO3 and BaCeO3 solid solutions are presented. The nanopowders were prepared by two innovative methods: self propagating room temperature synthesis (SPRT and modified glycine/nitrate procedure (MGNP. Different types of solid solutions with rare earth dopants in concentrations ranging from 0–0.25 mol% were synthesized. The reactions forming solid solutions were studied. In addition, the characteristics of prepared nanopowders, phenomena during sintering and the properties of sintered samples are discussed.

  4. Recent Structural Evolution of Early-Type Galaxies: Size Growth from z = 1 to z = 0

    Science.gov (United States)

    van der Wel, Arjen; Holden, Bradford P.; Zirm, Andrew W.; Franx, Marijn; Rettura, Alessandro; Illingworth, Garth D.; Ford, Holland C.

    2008-11-01

    Strong size and internal density evolution of early-type galaxies between z ~ 2 and the present has been reported by several authors. Here we analyze samples of nearby and distant (z ~ 1) galaxies with dynamically measured masses in order to confirm the previous, model-dependent results and constrain the uncertainties that may play a role. Velocity dispersion (σ) measurements are taken from the literature for 50 morphologically selected 0.8 University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  5. Effects of Type 2 Diabetes on Brain Structure and Cognitive Function: African American-Diabetes Heart Study MIND.

    Science.gov (United States)

    Whitlow, C T; Sink, K M; Divers, J; Smith, S C; Xu, J; Palmer, N D; Hugenschmidt, C E; Williamson, J D; Bowden, D W; Freedman, B I; Maldjian, J A

    2015-09-01

    Rates of type 2 diabetes are higher among African Americans compared with individuals of European ancestry. The purpose of this investigation was to determine the relationship between MR imaging measures of brain structure (volume of GM, WM, WM lesions) and cognitive function in a population of African Americans with type 2 diabetes. These MR imaging measures of brain structure are affected by type 2 diabetes-associated macrovascular and microvascular disease and may be associated with performance on tasks of cognitive function in the understudied African American population. African Americans with type 2 diabetes enrolled in the African American-Diabetes Heart Study MIND study (n = 263) were evaluated across a broad range of cognitive domains and imaged with brain MR imaging. Associations between cognitive parameters and MR imaging measures of whole-brain GM, WM, and WM lesion volumes were assessed by using adjusted multivariate models. Lower GM volume was associated with poorer performance on measures of general cognitive function, working memory, and executive function. Higher WM lesion volume was associated with poorer performance on a smaller subset of cognitive domains compared with GM volume but included aspects of working memory and executive function. There were no statistically significant associations with WM volume. Markers of cortical atrophy and WM lesion volume are associated with cognitive function in African Americans with type 2 diabetes. These associations are described in an African American cohort with disease control similar to that of individuals of European ancestry, rather than underserved African Americans with poor access to health care. Interventions to reduce cortical atrophy and WM disease may improve cognitive outcomes in this understudied population. © 2015 by American Journal of Neuroradiology.

  6. The Structure of the Poxvirus A33 Protein Reveals a Dimer of Unique C-Type Lectin-Like Domains

    Energy Technology Data Exchange (ETDEWEB)

    Su, Hua-Poo; Singh, Kavita; Gittis, Apostolos G.; Garboczi, David N. (NIH)

    2010-11-03

    The current vaccine against smallpox is an infectious form of vaccinia virus that has significant side effects. Alternative vaccine approaches using recombinant viral proteins are being developed. A target of subunit vaccine strategies is the poxvirus protein A33, a conserved protein in the Chordopoxvirinae subfamily of Poxviridae that is expressed on the outer viral envelope. Here we have determined the structure of the A33 ectodomain of vaccinia virus. The structure revealed C-type lectin-like domains (CTLDs) that occur as dimers in A33 crystals with five different crystal lattices. Comparison of the A33 dimer models shows that the A33 monomers have a degree of flexibility in position within the dimer. Structural comparisons show that the A33 monomer is a close match to the Link module class of CTLDs but that the A33 dimer is most similar to the natural killer (NK)-cell receptor class of CTLDs. Structural data on Link modules and NK-cell receptor-ligand complexes suggest a surface of A33 that could interact with viral or host ligands. The dimer interface is well conserved in all known A33 sequences, indicating an important role for the A33 dimer. The structure indicates how previously described A33 mutations disrupt protein folding and locates the positions of N-linked glycosylations and the epitope of a protective antibody.

  7. Primary volcanic structures from a type section of Deccan Trap flows ...

    Indian Academy of Sciences (India)

    Volcanic structures from Deccan Trap flows. 639. XI. 2 m thick, v ery fine ba sa lt ch ip s a lmost con v erted to b lack soil. 3.25 m ex p osed with. 0.7 m w ide co lumns. F ragm en ted en tab latu re zo ne w ith b o ulders v a ryin g in d iam . from. 6–8 cm. 5 m ex p o sedw ith0 .3 m w id e slender co lumns. 2 m th ick. , b lack soil w.

  8. A new type of artificial structure to achieve broadband omnidirectional acoustic absorption

    Directory of Open Access Journals (Sweden)

    Li-Yang Zheng

    2013-10-01

    Full Text Available We present a design for a two-dimensional omnidirectional acoustic absorber that can achieve 98.6% absorption of acoustic waves in water, forming an effective acoustic black hole. This artificial black hole consists of an absorptive core coated with layers of periodically distributed polymer cylinders embedded in water. Effective medium theory describes the response of the coating layers to the acoustic waves. The polymer parameters can be adjusted, allowing practical fabrication of the absorber. Since the proposed structure does not rely on resonances, it is applicable to broad bandwidths. The design might be extended to a variety of applications.

  9. A new type of artificial structure to achieve broadband omnidirectional acoustic absorption

    KAUST Repository

    Zheng, L.-Y.

    2013-10-18

    We present a design for a two-dimensional omnidirectional acoustic absorber that can achieve 98.6% absorption of acoustic waves in water, forming an effective acoustic black hole. This artificial black hole consists of an absorptive core coated with layers of periodically distributed polymer cylinders embedded in water. Effective medium theory describes the response of the coating layers to the acoustic waves. The polymer parameters can be adjusted, allowing practical fabrication of the absorber. Since the proposed structure does not rely on resonances, it is applicable to broad bandwidths. The design might be extended to a variety of applications.

  10. Cnidimonins A-C, Three Types of Hybrid Dimer from Cnidium monnieri: Structural Elucidation and Semisynthesis.

    Science.gov (United States)

    Su, Fangyi; Zhao, Zheng; Ma, Shuanggang; Wang, Rubing; Li, Yong; Liu, Yunbao; Li, Yuhuan; Li, Li; Qu, Jing; Yu, Shishan

    2017-09-15

    Three pairs of racemic dimers, (±)-cnidimonins A-C (1-3), were isolated from the fruits of Cnidium monnieri. They represent novel hybrid-dimerization patterns of coumarin skeleton with structurally diverse units (flavonol, benzofuran, and chromone) via an unprecedented terminal chiral carbon of prenyl. The absolute configurations of the enantiomers were determined by electronic circular dichroism (ECD). To investigate their bioactivities in depth, (±)-cnidimonins A-C (1-3) were synthesized. The racemic mixture (±)-1 exhibited stronger antiviral activity against HSV-1 (IC50: 1.23 μM) than its corresponding optically pure enantiomers.

  11. The type I interferon receptor: structure, function, and evolution of a family business.

    Science.gov (United States)

    Mogensen, K E; Lewerenz, M; Reboul, J; Lutfalla, G; Uzé, G

    1999-10-01

    Recent results indicate that coherent models of how multiple interferons (IFN) are recognized and signal selectively through a common receptor are now feasible. A proposal is made that the IFN receptor, with its subunits IFNAR-1 and IFNAR-2, presents two separate ligand binding sites, and this double structure is both necessary and sufficient to ensure that the different IFN are recognized and can act selectively. The key feature is the duplication of the extracellular domain of the IFNAR-1 subunit and the configurational geometry that this imposes on the intracellular domains of the receptor subunits and their associated tyrosine kinases.

  12. The Structures of Coiled-Coil Domains from Type III Secretion System Translocators Reveal Homology to Pore-Forming Toxins

    Energy Technology Data Exchange (ETDEWEB)

    Barta, Michael L.; Dickenson, Nicholas E.; Patil, Mrinalini; Keightley, Andrew; Wyckoff, Gerald J.; Picking, William D.; Picking, Wendy L.; Geisbrecht, Brian V. (UMKC); (OKLU)

    2012-03-26

    Many pathogenic Gram-negative bacteria utilize type III secretion systems (T3SSs) to alter the normal functions of target cells. Shigella flexneri uses its T3SS to invade human intestinal cells to cause bacillary dysentery (shigellosis) that is responsible for over one million deaths per year. The Shigella type III secretion apparatus is composed of a basal body spanning both bacterial membranes and an exposed oligomeric needle. Host altering effectors are secreted through this energized unidirectional conduit to promote bacterial invasion. The active needle tip complex of S. flexneri is composed of a tip protein, IpaD, and two pore-forming translocators, IpaB and IpaC. While the atomic structure of IpaD has been elucidated and studied, structural data on the hydrophobic translocators from the T3SS family remain elusive. We present here the crystal structures of a protease-stable fragment identified within the N-terminal regions of IpaB from S. flexneri and SipB from Salmonella enterica serovar Typhimurium determined at 2.1 {angstrom} and 2.8 {angstrom} limiting resolution, respectively. These newly identified domains are composed of extended-length (114 {angstrom} in IpaB and 71 {angstrom} in SipB) coiled-coil motifs that display a high degree of structural homology to one another despite the fact that they share only 21% sequence identity. Further structural comparisons also reveal substantial similarity to the coiled-coil regions of pore-forming proteins from other Gram-negative pathogens, notably, colicin Ia. This suggests that these mechanistically separate and functionally distinct membrane-targeting proteins may have diverged from a common ancestor during the course of pathogen-specific evolutionary events.

  13. Spectroscopic analysis on structure-affinity relationship in the interactions of different oleanane-type triterpenoids with bovine serum albumin.

    Science.gov (United States)

    Hou, Jia; Wang, Zhenzhong; Yue, Ying; Li, Qian; Shao, Shijun

    2015-09-01

    Oleanane-type triterpenoids serve as an important group of plant secondary metabolites with a variety of biological activities and the C-3 position substitution pattern is a significant structural feature for their biological activities. Three selected oleanane-type triterpenoids (glycyrrhizin, glycyrrhetinic acid, and carbenoxolone) bearing different substituents (glucuronic acid dimer, hydroxyl, and succinyl groups) at the C-3 position were studied for their affinities to bind bovine serum albumin (BSA) by steady-state fluorescence, synchronous, three-dimensional fluorescence and ultraviolet-visible (UV-vis) absorption spectra. The binding mechanism of the triterpenoids to BSA is due to the formation of the triterpenoids-BSA complex and the binding affinity is strongest for carbenoxolone and ranked in the order carbenoxolone > glycyrrhetinic acid > glycyrrhizin. The thermodynamic parameters calculated at different temperatures showed that triterpenoids binding to BSA primarily depended on hydrophobic interaction and hydrogen bonding. The distance between the bound triterpenoid and BSA was determined on the basis of the Förster's energy transfer theory. Displacement experiments using phenylbutazone and ibuprofen showed the binding site of triterpenoids on BSA at subdomain IIA (Sudlow's site I). The effect of triterpenoids on BSA conformation was analyzed by UV-vis absorption, and synchronous and three-dimensional fluorescence spectra. These results revealed that the C-3 position substitution pattern significantly affects the structure-affinity relationships of oleanane-type triterpenoid binding to BSA and further affects the bioavailability of triterpenoids in the blood circulatory system. Copyright © 2014 John Wiley & Sons, Ltd.

  14. Structural studies of P-type ATPase–ligand complexes using an X-ray free-electron laser

    Directory of Open Access Journals (Sweden)

    Maike Bublitz

    2015-07-01

    Full Text Available Membrane proteins are key players in biological systems, mediating signalling events and the specific transport of e.g. ions and metabolites. Consequently, membrane proteins are targeted by a large number of currently approved drugs. Understanding their functions and molecular mechanisms is greatly dependent on structural information, not least on complexes with functionally or medically important ligands. Structure determination, however, is hampered by the difficulty of obtaining well diffracting, macroscopic crystals. Here, the feasibility of X-ray free-electron-laser-based serial femtosecond crystallography (SFX for the structure determination of membrane protein–ligand complexes using microcrystals of various native-source and recombinant P-type ATPase complexes is demonstrated. The data reveal the binding sites of a variety of ligands, including lipids and inhibitors such as the hallmark P-type ATPase inhibitor orthovanadate. By analyzing the resolution dependence of ligand densities and overall model qualities, SFX data quality metrics as well as suitable refinement procedures are discussed. Even at relatively low resolution and multiplicity, the identification of ligands can be demonstrated. This makes SFX a useful tool for ligand screening and thus for unravelling the molecular mechanisms of biologically active proteins.

  15. Wave attenuation around a large pontoon-type floating structure; Pontoon gata choogata futai shui no haro gensui ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Kagemoto, H.; Fujino, M.; Ishii, H.; Yamashita, T. [The University of Tokyo, Tokyo (Japan)

    1996-10-01

    With an objective to identify actual conditions of wave attenuation at the bottom of an ultra-large floating structure, a model of a large pontoon-type floating structure was used to measure and discuss wave varying pressure distribution at the bottom of the floating structure subjected to regular waves. The experiment used a pontoon-type model having a length of 6.00 m and a depth of 1.20 m. A pressure sensor was embedded at the bottom of the floating body to measure the wave varying pressure. The experiment was performed in regular waves with wave amplitude kept constant nearly at 1.0 cm, and the wave cycle was changed between 0.475 and 1.000 sec. Angle of encounter with wave was set to four values of 0 degrees, 10 degrees, 45 degrees and 90 degrees. As a result of the experiment, it was verified that the wave varying pressure underneath the floating body agrees well with the linearity potential theoretical value, and the wave varying pressure attenuates to nearly zero inside the floating body from its end above waves to about one wave length. In addition, the pressure distribution in a direction perpendicular to waves was found nearly constant excepting the edges of the floating body. 3 refs., 7 figs.

  16. Cell type specificity and structural determinants of IRES activity from the 5' leaders of different HIV-1 transcripts.

    Science.gov (United States)

    Plank, Terra-Dawn M; Whitehurst, James T; Kieft, Jeffrey S

    2013-07-01

    Internal ribosome entry site (IRES) RNAs are important regulators of gene expression, but their diverse molecular mechanisms remain partially understood. The HIV-1 gag transcript leader contains an IRES that may be a good model for understanding the function of many other IRESs. We investigated the possibility that this IRES' function is linked to both the structure of the RNA and its cellular environment. We find that in the context of a bicistronic reporter construct, HIV-1 gag IRES' activity is cell type-specific, with higher activity in T-cell culture systems that model the natural target cells for HIV-1 infection. This finding underscores how an IRES may be fine tuned to function in certain cells, perhaps owing to cell type-specific protein factors. Using RNA probing and mutagenesis, we demonstrate that the HIV-1 gag IRES does not use pre-folded RNA structure to drive function, a finding that gives insight into how conformationally dynamic IRESs operate. Furthermore, we find that a common exon drives IRES activity in a diverse set of alternatively spliced transcripts. We propose a mechanism in which a structurally plastic RNA element confers the ability to initiate translation internally, and activity from this common element is modulated by 3' nucleotides added by alternative splicing.

  17. Structural studies of P-type ATPase–ligand complexes using an X-ray free-electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Bublitz, Maike; Nass, Karol; Drachmann, Nikolaj D.; Markvardsen, Anders J.; Gutmann, Matthias J.; Barends, Thomas R. M.; Mattle, Daniel; Shoeman, Robert L.; Doak, R. Bruce; Boutet, Sébastien; Messerschmidt, Marc; Seibert, Marvin M.; Williams, Garth J.; Foucar, Lutz; Reinhard, Linda; Sitsel, Oleg; Gregersen, Jonas L.; Clausen, Johannes D.; Boesen, Thomas; Gotfryd, Kamil; Wang, Kai-Tuo; Olesen, Claus; Møller, Jesper V.; Nissen, Poul; Schlichting, Ilme

    2015-06-11

    Membrane proteins are key players in biological systems, mediating signalling events and the specific transport ofe.g.ions and metabolites. Consequently, membrane proteins are targeted by a large number of currently approved drugs. Understanding their functions and molecular mechanisms is greatly dependent on structural information, not least on complexes with functionally or medically important ligands. Structure determination, however, is hampered by the difficulty of obtaining well diffracting, macroscopic crystals. Here, the feasibility of X-ray free-electron-laser-based serial femtosecond crystallography (SFX) for the structure determination of membrane protein–ligand complexes using microcrystals of various native-source and recombinant P-type ATPase complexes is demonstrated. The data reveal the binding sites of a variety of ligands, including lipids and inhibitors such as the hallmark P-type ATPase inhibitor orthovanadate. By analyzing the resolution dependence of ligand densities and overall model qualities, SFX data quality metrics as well as suitable refinement procedures are discussed. Even at relatively low resolution and multiplicity, the identification of ligands can be demonstrated. This makes SFX a useful tool for ligand screening and thus for unravelling the molecular mechanisms of biologically active proteins.

  18. Enhanced p-type behavior in the hybrid structure of graphene quantum dots/2D-WSe2

    Science.gov (United States)

    Liu, Ping; Zhu, Xingqun; Feng, Chao; Huang, Meng; Li, Jing; Lu, Yalin; Xiang, Bin

    2017-09-01

    Transition metal dichalcogenides (TMDs) have emerged as promising candidates for realizing p-n junction device applications. However, the realization of the modulation in the electronic properties of p-type TMDs still remains challenging. Here, we report an enhanced p-type electrical transport behavior in a hybrid structure of graphene quantum dot (GQD)/two dimensional (2D) WSe2. The incorporation of GQDs onto the surface of thin layer WSe2 triggers significantly the charge transfer from WSe2 to GQDs due to the band alignment at the interface. As a result, the increase in the spectral weight of positive charged trions occurs, leading to a red shift in the photoluminescence in the hybrid structure of GQD/WSe2. Because of the charge transfer, it results in 50-time improvement in the hole carrier mobility with a decreased threshold voltage in the hybrid structure compared to pristine WSe2. Our results pave the way for enhancing the performance of other 2D material-based electronic devices.

  19. Verification of the authenticity of handwritten signature using structure neural-network-type OCON

    Science.gov (United States)

    Molina, M. L.; Arias, N. A.; Gualdron, Oscar

    2004-10-01

    A method in order to carry out the verification of handwritten signatures is described. The method keeps in mind global features and local features that encode the shape and the dynamics of the signatures. Signatures are recorded with a digital tablet that can read the position and pressure of the pen. Input patterns are considered time and space dependent. Before extracting the information of the static features such as total length or height/width ratio, and the dynamic features such as speed or acceleration, the signature is normalized for position, size and orientation using its Fourier Descriptors. The comparison stage is carried out for algorithms of neurals networks. For each one of the sets of features a special two stage Perceptron OCON (one-class-one-network) classification structure has been implemented. In the first stage networks multilayer perceptron with few neurons are used. The classifier combines the decision results of the neural networks and the Euclidean distance obtained using the two feature sets. The results of the first-stage classifier feed a second-stage radial basis function (RBF) neural network structure, which makes the final decision. The entire system was extensively tested, 160 neurals networks has been implemented.

  20. Structure diversity in three forest types of north-eastern Thailand (Sakaerat Reserve, Pak Tong Chai

    Directory of Open Access Journals (Sweden)

    Malaisse F.

    1998-01-01

    Full Text Available The aim of the present study is to provide a basic knowledge in view of a better understanding of the global structure of threetropical forests at the Sakaerat Environmental Research Station (Pak Tong Chai district, Northeastern Thailand: a drydipterocarp forest (DDF, a dry evergreen forest (DEF and an intermediate stage (DDFwf, characterized by the absence offire since 29 years in a pyro-climax. These forest ecosystems were contrasted by the composition and floristic structure, thebasal area and the tree density. The species richness increases with the passage from the DDF, the most open environment, to the DDFwf, the most densely wooded. By these tree density and basal area, the DDF (602 trees/ha at DBH ³ 5 cm, 14.2 m2/ha and the DEF (992 trees/ha at DBH ³ 5 cm, 29.0 m2/ha studied belong to the typical tropical ecosytems of southeast Asia. The man-made fires and anarchic forest exploitations are a danger for the stability of these different ecosystems.

  1. Structure and function of a novel type of ATP-dependent Clp protease.

    Science.gov (United States)

    Andersson, Fredrik I; Tryggvesson, Anders; Sharon, Michal; Diemand, Alexander V; Classen, Mirjam; Best, Christoph; Schmidt, Ronny; Schelin, Jenny; Stanne, Tara M; Bukau, Bernd; Robinson, Carol V; Witt, Susanne; Mogk, Axel; Clarke, Adrian K

    2009-05-15

    The Clp protease is conserved among eubacteria and most eukaryotes, and uses ATP to drive protein substrate unfolding and translocation into a chamber of sequestered proteolytic active sites. The main constitutive Clp protease in photosynthetic organisms has evolved into a functionally essential and structurally intricate enzyme. The model Clp protease from the cyanobacterium Synechococcus consists of the HSP100 molecular chaperone ClpC and a mixed proteolytic core comprised of two distinct subunits, ClpP3 and ClpR. We have purified the ClpP3/R complex, the first for a Clp proteolytic core comprised of heterologous subunits. The ClpP3/R complex has unique functional and structural features, consisting of twin heptameric rings each with an identical ClpP3(3)ClpR(4) configuration. As predicted by its lack of an obvious catalytic triad, the ClpR subunit is shown to be proteolytically inactive. Interestingly, extensive modification to ClpR to restore proteolytic activity to this subunit showed that its presence in the core complex is not rate-limiting for the overall proteolytic activity of the ClpCP3/R protease. Altogether, the ClpP3/R complex shows remarkable similarities to the 20 S core of the proteasome, revealing a far greater degree of convergent evolution than previously thought between the development of the Clp protease in photosynthetic organisms and that of the eukaryotic 26 S proteasome.

  2. Place Of Hunting Tourism In The Structure Of Modern Tourism Types

    Directory of Open Access Journals (Sweden)

    Ioan Petroman

    2015-10-01

    Full Text Available From an economic and socialpoint of view, hunting tourism has two sub-categories: resident hunting andtourism hunting (for the travellers who travel long distances to participate inhunting. Tourism hunting covers six types of tourism: subsistence indigenoushunting, traditional hunting, commercial hunting, recreational-sport hunting,integrated hunting, and optimum level game maintenance hunting. Huntingtourists should be classified into three distinct categories: large gamehunting tourists (for whom what matters is adventure and trophies, small gamehunting tourists (interested in the hunting experience, and experiencedhunting tourists (characterised by the use of frontal charge guns or arrowshooting. Hunting tourism can be considered a sub-category of nature tourismbecause it contributes to the preservation of area biodiversity, of culturaltourism as educational, cultural activity, and of sustainable tourism inprotected areas (ecotourism whose hunting tourism sub-category is trophyhunting

  3. Seismic Experimental Study on New-Type Composite Exterior Wallboard with Integrated Structural Function and Insulation

    Directory of Open Access Journals (Sweden)

    Shaochun Ma

    2015-06-01

    Full Text Available In order to evaluate the seismic performance of new-type composite exterior wallboard, a total of six exterior and interior wallboards were incorporated in the experiment of seismic performance. Seismic performance such as the stress process, damage mode, hysteresis and skeleton curve, load-carrying and ductility coefficient, damping and energy dissipation, stiffness degradation as well as material strain of the exterior wallboards were analyzed with emphasis and compared with interior wallboards. Results of the experiment and analysis showed that both interior and exterior wallboards exhibited outstanding seismic performance. Due to the existence of insulation layer and externally bonded single gypsum board, the capacity of elastoplastic deformation and seismic energy dissipation of the exterior wallboards was improved and each seismic performance indicator of the exterior wallboards outperformed the interior wallboards.

  4. Structure and pathogenicity of antibodies specific for citrullinated collagen type II in experimental arthritis

    DEFF Research Database (Denmark)

    Uysal, Hüseyin; Bockermann, Robert; Nandakumar, Kutty S

    2009-01-01

    Antibodies to citrulline-modified proteins have a high diagnostic value in rheumatoid arthritis (RA). However, their biological role in disease development is still unclear. To obtain insight into this question, a panel of mouse monoclonal antibodies was generated against a major triple helical...... collagen type II (CII) epitope (position 359-369; ARGLTGRPGDA) with or without arginines modified by citrullination. These antibodies bind cartilage and synovial tissue, and mediate arthritis in mice. Detection of citrullinated CII from RA patients' synovial fluid demonstrates that cartilage-derived CII...... that autoimmunity to CII, leading to the production of antibodies specific for both native and citrullinated CII, is an important pathogenic factor in the development of RA....

  5. Application of cubane-type structures to hydro-treatment catalysis; Application des structures d'architecture cubane a la catalyse d'hydrotraitement

    Energy Technology Data Exchange (ETDEWEB)

    Marchand, K.

    2003-11-01

    [Mo{sub 3}S{sub 4}(H{sub 2}O){sub 9}]{sup 4+} has been prepared and supported on zeolites H-USY and NaY. Using this cluster as a precursor for HDT catalysts has many advantages: it is cationic, already in a sulfided form, and a promoter such as a second metal M' such as Cu, Ni or Pd can be incorporated to form Mo{sub 3}M'S{sub 4}{sup 4+}. The cubane structure was found unchanged after loading in the case of NaY (EXAFS, XPS) and although TEM showed that Mo was mainly on the outer surface of the zeolite crystals, DRX confirmed that a modification of the counter ion also occurred, and an isotherm was obtained with NaY zeolite. A thermal stability study was led under N{sub 2} and a mixture of H{sub 2}/H{sub 2}S to optimize the pretreatment of the catalysts. Those were subsequently pre-sulfided and tested in toluene hydrogenation and their activities with both types of zeolites turned out to be the same or even better than that of catalysts prepared by the classical route. An application to mixed cubane-type structures is also reported. (author)

  6. Reef fishes of Saba Bank, Netherlands Antilles: assemblage structure across a gradient of habitat types.

    Directory of Open Access Journals (Sweden)

    Wes Toller

    Full Text Available Saba Bank is a 2,200 km(2 submerged carbonate platform in the northeastern Caribbean Sea off Saba Island, Netherlands Antilles. The presence of reef-like geomorphic features and significant shelf edge coral development on Saba Bank have led to the conclusion that it is an actively growing, though wholly submerged, coral reef atoll. However, little information exists on the composition of benthic communities or associated reef fish assemblages of Saba Bank. We selected a 40 km(2 area of the bank for an exploratory study. Habitat and reef fish assemblages were investigated in five shallow-water benthic habitat types that form a gradient from Saba Bank shelf edge to lagoon. Significant coral cover was restricted to fore reef habitat (average cover 11.5% and outer reef flat habitat (2.4% and declined to near zero in habitats of the central lagoon zone. Macroalgae dominated benthic cover in all habitats (average cover: 32.5--48.1% but dominant algal genera differed among habitats. A total of 97 fish species were recorded. The composition of Saba Bank fish assemblages differed among habitat types. Highest fish density and diversity occurred in the outer reef flat, fore reef and inner reef flat habitats. Biomass estimates for commercially valued species in the reef zone (fore reef and reef flat habitats ranged between 52 and 83 g/m(2. The composition of Saba Bank fish assemblages reflects the absence of important nursery habitats, as well as the effects of past fishing. The relatively high abundance of large predatory fish (i.e. groupers and sharks, which is generally considered an indicator of good ecosystem health for tropical reef systems, shows that an intact trophic network is still present on Saba Bank.

  7. Performance of a novel type of electrolyte-supported solid oxide fuel cell with honeycomb structure

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Morales, Juan Carlos; Savvin, Stanislav N.; Nunez, Pedro [Departmento de Quimica Inorganica, Universidad de La Laguna, 38200 Tenerife (Spain); Marrero-Lopez, David [Departamento de Fisica Aplicada I, Universidad de Malaga, 29071 Malaga (Spain); Pena-Martinez, Juan; Canales-Vazquez, Jesus [Instituto de Energias Renovables-Universidad de Castilla la Mancha, 02006 Albacete (Spain); Roa, Joan Josep; Segarra, Merce [DIOPMA, Departamento de Ciencia de los Materiales e Ing. Metalurgica, 08028 Barcelona (Spain)

    2010-01-15

    A novel design, alternative to the conventional electrolyte-supported solid oxide fuel cell (SOFC) is presented. In this new design, a honeycomb-electrolyte is fabricated from hexagonal cells, providing high mechanical strength to the whole structure and supporting the thin layer used as electrolyte of a SOFC. This new design allows a reduction of {proportional_to}70% of the electrolyte material and it renders modest performances over 320 mW cm{sup -2} but high volumetric power densities, i.e. 1.22 W cm{sup -3} under pure CH{sub 4} at 900 C, with a high OCV of 1.13 V, using the standard Ni-YSZ cermet as anode, Pt as cathode material and air as the oxidant gas. (author)

  8. Citral degradation in micellar structures formed with polyoxyethylene-type surfactants.

    Science.gov (United States)

    Park, Sung Joon; Hong, Chi Rac; Choi, Seung Jun

    2015-03-01

    In a micellar solution, the chemical degradation of poorly water-soluble food flavours can be influenced by the properties of the surfactants forming the micelles in aqueous solutions. To evaluate how hydrophilic head size and hydrophobic tail length influence the chemical degradation rate of food flavour, micelles were prepared with Brij surfactants (Brij 35, 58, 78 and 700), each of which had very similar molecular structures (polyoxyethylene fatty acid ether). The chemical degradation of citral in Brij micelles was found to be highest in an acidic environment. There was no significant difference in the chemical degradation rate of citral in Brij micelles in non-acidic conditions, regardless of the hydrophilic head size or hydrophobic tail length. Brij surfactants with larger hydrophilic heads effectively retarded the chemical degradation of citral in an acidic environment. Our findings suggest that the length of the hydrophobic tail rarely influenced the micelle's ability to chemically stabilize citral. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Intelligence structure and personality in various types of physical handicap in childhood and adolescence.

    Science.gov (United States)

    Steinhausen, H C; Wefers, D

    1976-08-01

    Intelligence structure and personality were assessed in a sample of 104 physically disabled children of normal intelligence (IQ is greater than or equal to 85). Findings were compared to those of healthy controls matched by age, sex, rank order and number of siblings and socioeconomic status. Physically handicapped children had lower scores in all subtests of a multi-factorial intelligence test. Furthermore five different subgroups of physically disabled children could be discriminated along one factor marked by different variables of visual perception. Personality of the total group of handicapped children was different when compared to normal controls. This specific personality pattern may be labeled: lack of emotional integration into social environment without conflict. Various subgroups of physically handicapped children differed only little as far as personality is concerned.

  10. Structure elucidation of new oleanane-type glycosides from three species of Acanthophyllum.

    Science.gov (United States)

    Timité, Gaoussou; Mitaine-Offer, Anne-Claire; Miyamoto, Tomofumi; Ramezani, Mohammad; Rustaiyan, Abdolhossein; Mirjolet, Jean-François; Duchamp, Olivier; Lacaille-Dubois, Marie-Aleth

    2010-05-01

    From the roots of three species of Acanthophyllum (Caryophyllaceae), two new gypsogenic acid glycosides, 1 and 2, were isolated, 1 from A. sordidum and A. lilacinum, 2 from A. elatius and A. lilacinum, together with three known saponins, glandulosides B and C, and SAPO50. The structures of 1 and 2 were established mainly by 2D NMR techniques as 23-O-beta-D-galactopyranosylgypsogenic acid-28-O-beta-D-glucopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->6)]-beta-D-galactopyranoside (1) and gypsogenic acid-28-O-beta-D-glucopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->6)]-beta-D-galactopyranoside (2). The cytotoxicity of several of these saponins was evaluated against two human colon cancer cell lines (HT-29 and HCT 116). Copyright 2010 John Wiley & Sons, Ltd.

  11. A method for acoustic source location in plate-type structures

    Science.gov (United States)

    Mostafapour, Amir; Davoodi, Saman

    2017-09-01

    In this study an algorithm based on Shannon entropy, cross-time frequency spectrum (CTFS) and frequency varying velocities was proposed for structure health monitoring in two-layer plate. A linear array of two sensors is applied to capture the signals. By reducing the number of sensors we used a secondary pattern to get enough information for source locating. For this purpose a pattern for secondary points based on Shannon entropy and cost function was developed. Then to estimate the time delay of signals, cross-time frequency spectrum function was taken from captured signals. The time delay was calculated when CTFS function reached the maximum value. By taking short time Fourier transform of cross correlation function of captures signals and using dispersive curves, time delay and corresponding frequency dependent velocity are estimated. The experiments were carried out and the results showed high precision of presented algorithm.

  12. Isolation and Structure Elucidation of GM4-Type Gangliosides from the Okinawan Starfish Protoreaster nodosus

    Directory of Open Access Journals (Sweden)

    Tomofumi Miyamoto

    2012-11-01

    Full Text Available Three new ganglioside molecular species, termed PNG-1, PNG-2A, and PNG-2B were isolated from pyloric caeca of the starfish Protoreaster nodosus. Their structures were elucidated using a combination of spectroscopic and chemical methods, and characterized as 1-O-[8-O-methyl-N-acetyl-α-neuraminosyl-(2→3-β-galactopyranosyl]-ceramide for PNG-1, 1-O-[β-galactofuranosyl-(1→3-α-galactopyranosyl-(1→4-8-O-methyl-N-acetyl-α-neuraminosyl-(2→3-β-galactopyranosyl]-ceramide for PNG-2A, and 1-O-[β-galacto furanosyl-(1→3-α-galactopyranosyl-(1→9-N-acetyl-α-neuraminosyl-(2→3-β-galactopyr anosyl]-ceramide for PNG-2B. PNG-2A and PNG-2B represent the first GM4 elongation products in nature.

  13. Isolation and Structure Elucidation of GM4-Type Gangliosides from the Okinawan Starfish Protoreaster nodosus

    Science.gov (United States)

    Pan, Ke; Tanaka, Chiaki; Inagaki, Masanori; Higuchi, Ryuichi; Miyamoto, Tomofumi

    2012-01-01

    Three new ganglioside molecular species, termed PNG-1, PNG-2A, and PNG-2B were isolated from pyloric caeca of the starfish Protoreaster nodosus. Their structures were elucidated using a combination of spectroscopic and chemical methods, and characterized as 1-O-[8-O-methyl-N-acetyl-α-neuraminosyl-(2→3)-β-galactopyranosyl]-ceramide for PNG-1, 1-O-[β-galactofuranosyl-(1→3)-α-galactopyranosyl-(1→4)-8-O-methyl-N-acetyl-α-neuraminosyl-(2→3)-β-galactopyranosyl]-ceramide for PNG-2A, and 1-O-[β-galactofuranosyl-(1→3)-α-galactopyranosyl-(1→9)-N-acetyl-α-neuraminosyl-(2→3)-β-galactopyranosyl]-ceramide for PNG-2B. PNG-2A and PNG-2B represent the first GM4 elongation products in nature. PMID:23203271

  14. Phosphovanadylite: a new vanadium phosphate mineral with a zeolite-type structure

    Science.gov (United States)

    Medrano, M.D.; Evans, H.T.; Wenk, H.-R.; Piper, D.Z.

    1998-01-01

    Phosphovanadylite, whose simplified formula is (Ba,Ca,K,Na)x([(Va,Al)4P2(P,OH)16].12H2), is a new vanadium phosphate zeolite mineral found in the Phosphoria Formation at Monsanto's Enoch Valley Mine, Soda Springs, Idaho. Its formula in more detail is (Ba0.38Ca0.20K0.006Na0.02)??0.66 [P2(V3.44Al0.046)??3.90O10.34(OH)5.66] .12H2O. The drusy mineral occurs as pale greenish-blue euhedral cubes (20-50 ??m edge) coating phosphatic, organic-rich mudstone. The chemical composition determined by electron microprobe is (in weight percent) V-28.02, P-9.91, Al-1.97, Ca-1.31, Ba-8.28, Cd-0.09, Zn-0.34, Na-0.15, K-0.73, O-46.57, and F-0.03. The index of refraction is nD = 1.566 (4) and specific gravity is 2.16 (3). The X-ray powder pattern shows strong reflections at 3.16 A (422), 2.58 (600), 2.44 (620), and 7.73 (200), which are indexed on the basis of a cubic body-centered unit cell with a = 15.470 (4) A. From the single-crystal structure analysis, its space group was determined to be I43m, Z = 6, and its structure consists of V4O18 16 octahedral clusters linked to each other by P atoms to form a cubic lattice, creating cavities 7.0 and 5.5 A in diameter where mainly H2O resides. Final residual indexes are R = 0.066, Rw = 0.061, goodness-of-fit = 0.75, and 93 observations and 24 parameters.

  15. Removal of dentin non-collagenous structures results in the unraveling of microfibril bundles in collagen type I.

    Science.gov (United States)

    Bertassoni, Luiz E; Swain, Michael V

    2017-09-01

    The structural organization of collagen from mineralized tissues, such as dentin and bone, has been a topic of debate in the recent literature. Recent reports have presented novel interpretations of the complexity of collagen type I at different hierarchical levels and in different tissues. Here, we investigate the nanostructural organization of demineralized dentin collagen following the digestion of non-collagenous components with a trypsin enzyme. Dentin specimens were obtained from healthy third-molars, cut into small cubes, and polished down to 1 µm roughness. Samples were then demineralized with 10% citric acid for 2 min. Selected specimens were further treated with a solution containing 1 mg/ml trypsin for 48 hours at 37 °C (pH 7.9-9.0). Both untreated and trypsin digested samples were analyzed using SDS-PAGE, Field Emission Scanning Electron Microscopy (FE-SEM), and nanoindentation, where surface hardness and creep properties were compared before and after treatments. FE-SEM images of demineralized dentin showed the banded morphology of D-periodical collagen type I, which upon enzymatic digestion with trypsin appeared to dissociate longitudinally, consistently unraveling ~20 nm structures (microfibril bundles). Such nanoscale structures, to the best of our knowledge, have not been characterized in dentin previously. Mechanical characterization via nanoindentation showed that the unraveling of such microfibril bundles affected the creep displacement and creep rate of demineralized dentin. In summary, our results provide novel evidence of the organization of collagen type I from dentin, which may have important implications for the interaction of dental materials with the organic dentin matrix and the mechanical properties of mineralized tissues.

  16. Genome-scale multilocus microsatellite typing of Trypanosoma cruzi discrete typing unit I reveals phylogeographic structure and specific genotypes linked to human infection.

    Directory of Open Access Journals (Sweden)

    Martin S Llewellyn

    2009-05-01

    Full Text Available Trypanosoma cruzi is the most important parasitic infection in Latin America and is also genetically highly diverse, with at least six discrete typing units (DTUs reported: Tc I, IIa, IIb, IIc, IId, and IIe. However, the current six-genotype classification is likely to be a poor reflection of the total genetic diversity present in this undeniably ancient parasite. To determine whether epidemiologically important information is "hidden" at the sub-DTU level, we developed a 48-marker panel of polymorphic microsatellite loci to investigate population structure among 135 samples from across the geographic distribution of TcI. This DTU is the major cause of resurgent human disease in northern South America but also occurs in silvatic triatomine vectors and mammalian reservoir hosts throughout the continent. Based on a total dataset of 12,329 alleles, we demonstrate that silvatic TcI populations are extraordinarily genetically diverse, show spatial structuring on a continental scale, and have undergone recent biogeographic expansion into the southern United States of America. Conversely, the majority of human strains sampled are restricted to two distinct groups characterised by a considerable reduction in genetic diversity with respect to isolates from silvatic sources. In Venezuela, most human isolates showed little identity with known local silvatic strains, despite frequent invasion of the domestic setting by infected adult vectors. Multilocus linkage indices indicate predominantly clonal parasite propagation among all populations. However, excess homozygosity among silvatic strains and raised heterozygosity among domestic populations suggest that some level of genetic recombination cannot be ruled out. The epidemiological significance of these findings is discussed.

  17. A near-infrared census of the multicomponent stellar structure of early-type dwarf galaxies in the Virgo cluster

    Energy Technology Data Exchange (ETDEWEB)

    Janz, J.; Laurikainen, E.; Salo, H. [Division of Astronomy, Department of Physics, P.O. Box 3000, FI-90014 University of Oulu (Finland); Lisker, T.; Hansson, K. S. A.; Meyer, H. T.; Paudel, S. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstraße 12-14, D-69120 Heidelberg (Germany); Peletier, R. F.; Den Brok, M. [Kapteyn Astronomical Institute, University of Groningen, P.O. Box 800, 9700 AV Groningen (Netherlands); Niemi, S.-M. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom); Toloba, E. [UCO/Lick Observatory, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Hensler, G. [University of Vienna, Department of Astrophysics, Türkenschanzstraße 17, 1180 Vienna (Austria); Falcón-Barroso, J.; Ryś, A. [Instituto de Astrofísica de Canarias, Vía Láctea s/n, La Laguna, Tenerife (Spain); Boselli, A., E-mail: jjanz@ari.uni-heidelberg.de [CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, Aix Marseille Université, F-13388 Marseille (France)

    2014-05-10

    The fraction of star-forming to quiescent dwarf galaxies varies from almost infinity in the field to zero in the centers of rich galaxy clusters. What is causing this pronounced morphology-density relation? What do quiescent dwarf galaxies look like when studied in detail, and what conclusions can be drawn about their formation mechanism? Here we study a nearly magnitude-complete sample (–19 < M{sub r} < –16 mag) of 121 Virgo cluster early types with deep near-infrared images from the SMAKCED project. We fit two-dimensional models with optional inner and outer components, as well as bar and lens components (in ∼15% of the galaxies), to the galaxy images. While a single Sérsic function may approximate the overall galaxy structure, it does not entirely capture the light distribution of two-thirds of our galaxies, for which multicomponent models provide a better fit. This fraction of complex galaxies shows a strong dependence on luminosity, being larger for brighter objects. We analyze the global and component-specific photometric scaling relations of early-type dwarf galaxies and discuss similarities with bright early and late types. The dwarfs' global galaxy parameters show scaling relations that are similar to those of bright disk galaxies. The inner components are mostly fitted with Sérsic n values close to 1. At a given magnitude, they are systematically larger than the bulges of spirals, suggesting that they are not ordinary bulges. We argue that the multicomponent structures in early-type dwarfs are mostly a phenomenon inherent to the disks and may indeed stem from environmental processing.

  18. Two types of impact melts with contrasting magnetic mineralogy from Jänisjärvi impact structure, Russian Karelia

    Science.gov (United States)

    Sergienko, Elena S.; Kosterov, Andrei; Kharitonskii, Petr V.

    2017-05-01

    Palaeomagnetic and rock magnetic studies of impact-related rocks can provide important constraints for deciphering geophysical records from suspected impact structures, their geochronology, and, in the case of very large impacts, their effect on the Earth as a whole. However, the palaeomagnetic record in impact-related rocks may be ambiguous because of the uncertain origin of their natural remanent magnetization (NRM). Towards this end, we carried out a comprehensive rock magnetic and mineralogical study of tagamites (impact melts) from the Jänisjärvi astrobleme, Russian Karelia. Chemical composition of magnetic minerals and non-magnetic matrix was evaluated by scanning electron microscopy (SEM) and X-ray analysis. Magnetic minerals were identified using thermomagnetic analysis at high and low temperatures, whereas their domain state was evaluated from hysteresis measurements and magnetic force microscopy. Jänisjärvi tagamites appear to belong to two essentially different types arising from the differences in the impact melt crystallization conditions. Type I tagamites were likely formed by an extremely rapid cooling of a superhot melt with initial temperatures well above 2000 °C. Type II tagamites originate from cooler and more iron-enriched melt. Common to the two types is that they both contain a substantial amount of fine inclusions in silicate matrix tens of nanometres to few micrometres in size, which appear to be a major, in some cases dominant, magnetic mineral carrying a significant part of rocks NRM. Structurally, these inclusions are heterogeneous objects consisting of two phases showing both chemical and magnetic contrast.

  19. The Deep-Sea Polyextremophile Halobacteroides lacunaris TB21 Rough-Type LPS: Structure and Inhibitory Activity towards Toxic LPS

    Science.gov (United States)

    Di Lorenzo, Flaviana; Palmigiano, Angelo; Paciello, Ida; Pallach, Mateusz; Garozzo, Domenico; Bernardini, Maria-Lina; La Cono, Violetta; Yakimov, Michail M.; Molinaro, Antonio; Silipo, Alba

    2017-01-01

    The structural characterization of the lipopolysaccharide (LPS) from extremophiles has important implications in several biomedical and therapeutic applications. The polyextremophile Gram-negative bacterium Halobacteroides lacunaris TB21, isolated from one of the most extreme habitats on our planet, the deep-sea hypersaline anoxic basin Thetis, represents a fascinating microorganism to investigate in terms of its LPS component. Here we report the elucidation of the full structure of the R-type LPS isolated from H. lacunaris TB21 that was attained through a multi-technique approach comprising chemical analyses, NMR spectroscopy, and Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry. Furthermore, cellular immunology studies were executed on the pure R-LPS revealing a very interesting effect on human innate immunity as an inhibitor of the toxic Escherichia coli LPS. PMID:28653982

  20. Effect of Correlation Structure in Generalized Estimating Equation and Quasi Least Square: An Application in Type 2 Diabetes Patient

    Directory of Open Access Journals (Sweden)

    Dilip C Nath

    2011-07-01

    Full Text Available The Quasi-Least Squares (QLS is useful for different correlation structure with attachment of Generalized Estimating Equation (GEE. The purpose of this work is to compare the regression parameter in the presence of different correlation structure with respect to GEE and QLS method. The comparison of estimated regression parameter has been performed in clinical trial data set; studying the effect of drug treatment (metformin with pioglitazone Vs (gliclazide with pioglitazone in type 2 diabetes patients. In case of QLS, the correlation coefficient of post-parandinal blood sugar (PPBS under tridiagonal correlation is 0.008 while it failed to produce by GEE. It has been found that the combination of metformin with pioglitazone is more effective as compared to the combination of gliclazide with pioglitazone.

  1. Effect of Correlation Structure in Generalized Estimating Equation and Quasi Least Square: An Application in Type 2 Diabetes Patient

    Directory of Open Access Journals (Sweden)

    Dilip C Nath

    2011-08-01

    Full Text Available The Quasi-Least Squares (QLS is useful for different correlation structure with attachment of Generalized Estimating Equation (GEE. The purpose of this work is to compare the regression parameter in the presence of different correlation structure with respect to GEE and QLS method. The comparison of estimated regression parameter has been performed in clinical trial data set; studying the effect of drug treatment (metformin with pioglitazone Vs (gliclazide with pioglitazone in type 2 diabetes patients. In case of QLS, the correlation coefficient of post-parandinal blood sugar (PPBS under tridiagonal correlation is 0.008 while it failed to produce by GEE. It has been found that the combination of metformin with pioglitazone is more effective as compared to the combination of gliclazide with pioglitazone.

  2. Syntheses, Crystal Structures and Thermal Behaviors of Two Supramolecular Salamo-Type Cobalt(II and Zinc(II Complexes

    Directory of Open Access Journals (Sweden)

    Gang Li

    2017-07-01

    Full Text Available This paper reports the syntheses of two new complexes, [Co(L1(H2O2] (1 and [{Zn(L2(μ-OAcZn(n-PrOH}2] (2, from asymmetric halogen-substituted Salamo-type ligands H2L1 and H3L2, respectively. Investigation of the crystal structure of complex 1 reveals that the complex includes one Co(II ion, one (L12− unit and two coordinated water molecules. Complex 1 shows slightly distorted octahedral coordination geometry, forming an infinite 2D supramolecular structure by intermolecular hydrogen bond and π–π stacking interactions. Complex 2 contains four Zn(IIions, two completely deprotonated (L23− moieties, two coordinated μ-OAc− ions and n-propanol molecules. The Zn(II ions in complex 2 display slightly distorted trigonal bipyramidal or square pyramidal geometries.

  3. Wind Load Design of Hangar-Type Closed Steel Structures with Different Roof Pitches Using Abaqus CAE Software

    Directory of Open Access Journals (Sweden)

    Aybike Özyüksel Çiftçioğlu

    2017-05-01

    Full Text Available Structures convert the kinetic energy available in the air into potential energy which is in the form of pressure and suction forces reducing or fully stopping its motion. The potential impact of the wind depends on the geometric properties and pertinacity of a building, the angle of the wind flow, its strength and velocity. Design gains importance for tall buildings against the impact of the resonance along with the force based on pressure. Relevant calculations are made in Turkey based on the TS 498 Wind Load Velocity Criterion and this standard is currently being updated. This study develops the wind load design of hangar-type closed steel structures with different roof pitches using Abaqus CAE software.

  4. Biphenyl derived oxovanadium(IV) and copper(II) salen-type complexes--structure and redox tuning.

    Science.gov (United States)

    Plitt, Patrick; Pritzkow, Hans; Oeser, Thomas; Kraemer, Roland

    2005-05-01

    A series of vanadyl(IV) salen (N,N'-bis(salicylidene)ethylenediaminato)-type complexes (1-4) bearing phenyl or 2-hydroxyphenyl moieties have been prepared and characterized by means of mass spectrometry, infra-red, electron paramagnetic resonance (EPR), UV/Vis spectroscopy, cyclovoltammetry and X-ray crystallography. Their structures have been compared to their copper(II) analogs 5-8. Hydrogen intralinkages have been observed in the crystal structure of 5. The pendant hydroxy groups fine-tune the redox properties of the complexes. The catalytic activity in the oxygenation of ethyl phenyl sulfide to the corresponding sulfoxide was investigated. Results indicate that complex 1 bearing hydroxyphenyl subunits and a phenylene bridge is the most selective under these reaction conditions, with the smallest amount of the over-oxidized product, sulfone.

  5. Experimental and theoretical investigations of the electronic band structure of metal-organic frameworks of HKUST-1 type

    Science.gov (United States)

    Gu, Zhi-Gang; Heinke, Lars; Wöll, Christof; Neumann, Tobias; Wenzel, Wolfgang; Li, Qiang; Fink, Karin; Gordan, Ovidiu D.; Zahn, Dietrich R. T.

    2015-11-01

    The electronic properties of metal-organic frameworks (MOFs) are increasingly attracting the attention due to potential applications in sensor techniques and (micro-) electronic engineering, for instance, as low-k-dielectric in semiconductor technology. Here, the band gap and the band structure of MOFs of type HKUST-1 are studied in detail by means of spectroscopic ellipsometry applied to thin surface-mounted MOF films and by means of quantum chemical calculations. The analysis of the density of states, the band structure, and the excitation spectrum reveal the importance of the empty Cu-3d orbitals for the electronic properties of HKUST-1. This study shows that, in contrast to common belief, even in the case of this fairly "simple" MOF, the excitation spectra cannot be explained by a superposition of "intra-unit" excitations within the individual building blocks. Instead, "inter-unit" excitations also have to be considered.

  6. Experimental and theoretical investigations of the electronic band structure of metal-organic frameworks of HKUST-1 type

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Zhi-Gang [Institut für Funktionelle Grenzflächen (IFG), Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, 350002 Fuzhou (China); Heinke, Lars, E-mail: Lars.Heinke@KIT.edu; Wöll, Christof [Institut für Funktionelle Grenzflächen (IFG), Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Neumann, Tobias; Wenzel, Wolfgang; Li, Qiang; Fink, Karin [Institute of Nanotechnology (INT), Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Gordan, Ovidiu D.; Zahn, Dietrich R. T. [Semiconductor Physics, Technische Universität Chemnitz, 09107 Chemnitz (Germany)

    2015-11-02

    The electronic properties of metal-organic frameworks (MOFs) are increasingly attracting the attention due to potential applications in sensor techniques and (micro-) electronic engineering, for instance, as low-k-dielectric in semiconductor technology. Here, the band gap and the band structure of MOFs of type HKUST-1 are studied in detail by means of spectroscopic ellipsometry applied to thin surface-mounted MOF films and by means of quantum chemical calculations. The analysis of the density of states, the band structure, and the excitation spectrum reveal the importance of the empty Cu-3d orbitals for the electronic properties of HKUST-1. This study shows that, in contrast to common belief, even in the case of this fairly “simple” MOF, the excitation spectra cannot be explained by a superposition of “intra-unit” excitations within the individual building blocks. Instead, “inter-unit” excitations also have to be considered.

  7. Bacterial eukaryotic type serine-threonine protein kinases: from structural biology to targeted anti-infective drug design.

    Science.gov (United States)

    Danilenko, Valery N; Osolodkin, Dmitry I; Lakatosh, Sergey A; Preobrazhenskaya, Maria N; Shtil, Alexander A

    2011-01-01

    Signaling through protein kinases is an evolutionary conserved, widespread language of biological regulation. The eukaryotic type serine-threonine protein kinases (STPKs) found in normal human microbiote and in pathogenic bacteria play a key role in regulation of microbial survival, virulence and pathogenicity. Therefore, down-regulation of bacterial STPKs emerges as an attractive approach to cure infections. In this review we focused on actinobacterial STPKs to demonstrate that these enzymes can be used for crystal structure studies, modeling of 3D structure, construction of test systems and design of novel chemical libraries of low molecule as weight inhibitors. In particular, the prototypic pharmacological antagonists of Mycobacterium tuberculosis STPKs are perspective for development of a novel generation of drugs to combat the socially important disease. These inhibitors may modulate both actinobacterial and host STPKs and trigger programmed death of pathogenic bacteria.

  8. Energy spectrum of quantum wells in PbTe/PbEuTe type structures based on photoluminescence data

    CERN Document Server

    Zasavitskij, I I; Abramof, E

    2002-01-01

    The effect of the dimensional quantization and temperature on the energy spectrum of structures with the quantum wells of the PbTe/PbEuTe-type is studied. The calculated spectrum is compared with the data on the photoluminescence spectra, measured at 4.2 and 77.4 K. The energies of the emitting transitions are well described within the frames of the two-zone model with an account of the nonparabolicity, anisotropy and PbTe multivalley structure as well as by the uniaxial deformation, available in the heterostructures. It is established, that by decrease in the E sub g forbidden zone width the dE sub g /dT temperature coefficient in the two-dimensional heterostructure decreases, which is explained by weakening the electron-phonon interaction

  9. An area-efficient topology for VLSI implementation of Viterbi decoders and other shuffle-exchange type structures

    DEFF Research Database (Denmark)

    Sparsø, Jens; Jørgensen, Henrik Nordtorp; Paaske, Erik

    1991-01-01

    A topology for single-chip implementation of computing structures based on shuffle-exchange (SE)-type interconnection networks is presented. The topology is suited for structures with a small number of processing elements (i.e. 32-128) whose area cannot be neglected compared to the area required......- mu m CMOS process using MOSIS-like simplified design rules. The chip operates at speeds up to 19 MHz under worst-case conditions (V/sub DD/=4.75 V and T/sub A/=70 degrees C). The core of the chip (excluding pad cells) is 7.8*5.1 mm/sup 2/ and contains approximately 50000 transistors...

  10. Studies on the peroxisomal multifunctional enzyme type-1:domain structure with special reference to the hydratase/isomerase fold

    OpenAIRE

    Kiema, T.-R. (Tiila-Riikka)

    2001-01-01

    Abstract The peroxisomal multifunctional enzyme type-1 (perMFE-1) is a monomeric protein of β-oxidation possessing 2-enoyl-CoA hydratase-1, Δ3-Δ 2-enoyl-CoA isomerase, and (3S)-hydroxyacyl-CoA dehydrogenase activities. The amino-terminal part of perMFE-1 shows sequence similarity to mitochondrial 2-enoyl-CoA hydratases (ECH-1) and Δ3-Δ 2-enoyl-CoA isomerases, and belongs to the hydratase/isomerase superfamily. Family members with known structures are either...

  11. Quantification of age-related changes in the structure model type and trabecular thickness of human tibial cancellous

    DEFF Research Database (Denmark)

    Ding, Ming; Hvid, I

    2000-01-01

    Structure model type and trabecular thickness are important characteristics in describing cancellous bone architecture. It has been qualitatively observed that a radical change of trabeculae from plate-like to rod-like occurs in aging, bone remodeling, and osteoporosis. Thickness of trabeculae has......) cancellous bone. In this study, 160 human proximal tibial cancellous bone specimens from 40 normal donors, aged 16 to 85 years, were collected. These specimens were micro-computed tomography (micro-CT) scanned, then the micro-CT images were segmented using optimal thresholds. From accurate 3-D data sets...

  12. Analysis of the Local Budget’s Expenditures Structure at Different Types of Administrative Units in Romania

    Directory of Open Access Journals (Sweden)

    Dan-Constantin Danuletiu

    2016-01-01

    Full Text Available Financial decentralization process affected the expenditure part of the local budgets in Romania by imposing new destinations for own revenues, but also by limiting the decision autonomy because of the equalization system design or the transfer of responsibilities without establishing new sources of revenues. But the effects on the local budgets are not the same for every administrative unit. The article highlights the structure of expenditures of local budgets for different types of administrative unit, for identifying variations in and potential causes of the financial autonomy regarding local expenditures.

  13. Structural characterization of Ni and Ni/Ti ohmic contact on n-type 4H-SiC

    Energy Technology Data Exchange (ETDEWEB)

    Siad, M., E-mail: siadmenouar@yahoo.fr [Centre de Recherche Nucleaire d' Alger, 02 Bd Frantz Fanon (Algeria); Abdesselam, M. [USTHB, Faculte de Physique, BP 32, El Alia, Bab Ezzouar (Algeria); Souami, N. [Centre de Recherche Nucleaire d' Alger, 02 Bd Frantz Fanon (Algeria); Chami, A.C. [USTHB, Faculte de Physique, BP 32, El Alia, Bab Ezzouar (Algeria)

    2011-10-01

    In this study, we report on the structural characterization of Ni layer and Ni/Ti bilayer contacts on n-type 4H-SiC. The resulting Ni-silicides and the redistribution of carbon, after annealing at 950 deg. C, in the Ni/SiC and the Ni/Ti/SiC contacts are particularly studied by Rutherford Backscattering Spectrometry (RBS) at E{sub {alpha}} = 3.2 MeV, nuclear reaction analysis (NRA) at E{sub d} = 1 MeV, scanning electron microscopy (SEM) and Energy Dispersive X-ray Spectrometry (EDS) techniques.

  14. Performance of DFT+U method for prediction of structural and thermodynamic parameters of monazite-type ceramics.

    Science.gov (United States)

    Blanca Romero, Ariadna; Kowalski, Piotr M; Beridze, George; Schlenz, Hartmut; Bosbach, Dirk

    2014-07-05

    We performed a density functional theory (DFT) study of the monazite-type ceramics using DFT+U method, where the Hubbard U parameters are derived ab initio, with the main goal in testing the predictive power of this computational method for modeling of f-electron materials that are of interest in nuclear waste management. We show that DFT+U approach with PBEsol as the exchange-correlation functional significantly improves description of structures and thermodynamic parameters of lanthanide-bearing oxides and monazites over commonly used standard DFT (PBE) approach. We found that it is essential to use the Hubbard U parameter derived for a given element and a given structure to reproduce the structural parameters of the measured materials. We obtained exceptionally good description of the structural parameters with U parameter derived using the linear response approach of Cococcioni and de Gironcoli (Phys. Rev. B 2005, 71, 035105). This shows that affordable methods, such as DFT+U with a clever choice of exchange-correlation functional and the Hubbard U parameter can lead to a good description of f-electron materials. Copyright © 2014 Wiley Periodicals, Inc.

  15. Organosilane with gemini-type structure as the mesoporogen for synthesis of hierarchical porous ZSM-5 zeolite

    KAUST Repository

    Zhu, Haibo

    2016-02-08

    A new kind of organosilane (1,6-bis (diethyl(3-trimethoxysilylpropyl)ammonium) hexane bromide) with a gemini-type structure was prepared and used as a mesoporogen for the synthesis of hierarchical porous ZSM-5 zeolite. There are two quaternary ammonium centers along with double hydrolysable -RSi(OMe)3 fragments in the organosilane, which results in a strong interaction between this mesoporogen and silica-alumina gel. The organosilane can be easily incorporated into ZSM-5 zeolite structure during the crystallization process, and it was finally removed by calcination leading to secondary pores in ZSM-5. The synthesized ZSM-5 has been systematically studied by XRD, nitrogen adsorption, SEM, TEM, TG and solid-state one-dimensional (1D) and two-dimensional (2D) NMR, which reveals information on its detailed structure. It has a hierarchical porosity system, which combines the intrinsic micropores coming from the crystalline structure and irregular mesopores created by the organosilane template. Moreover, the mesoposity including pore size and volume within ZSM-5 can be systematically tuned by changing the organosilane/TEOS ratios, which confirms this organosilane has high flexibility of using as template for the synthesis of hierarchical porous zeolite.

  16. Structure of EspB from the ESX-1 type VII secretion system and insights into its export mechanism.

    Science.gov (United States)

    Solomonson, Matthew; Setiaputra, Dheva; Makepeace, Karl A T; Lameignere, Emilie; Petrotchenko, Evgeniy V; Conrady, Deborah G; Bergeron, Julien R; Vuckovic, Marija; DiMaio, Frank; Borchers, Christoph H; Yip, Calvin K; Strynadka, Natalie C J

    2015-03-03

    Mycobacterium tuberculosis (Mtb) uses the ESX-1 type VII secretion system to export virulence proteins across its lipid-rich cell wall, which helps permeabilize the host's macrophage phagosomal membrane, facilitating the escape and cell-to-cell spread of Mtb. ESX-1 membranolytic activity depends on a set of specialized secreted Esp proteins, the structure and specific roles of which are not currently understood. Here, we report the X-ray and electron microscopic structures of the ESX-1-secreted EspB. We demonstrate that EspB adopts a PE/PPE-like fold that mediates oligomerization with apparent heptameric symmetry, generating a barrel-shaped structure with a central pore that we propose contributes to the macrophage killing functions of EspB. Our structural data also reveal unexpected direct interactions between the EspB bipartite secretion signal sequence elements that form a unified aromatic surface. These findings provide insight into how specialized proteins encoded within the ESX-1 locus are targeted for secretion, and for the first time indicate an oligomerization-dependent role for Esp virulence factors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Structural and Functional Characterization of the Bacterial Type III Secretion Export Apparatus.

    Directory of Open Access Journals (Sweden)

    Tobias Dietsche

    2016-12-01

    Full Text Available Bacterial type III protein secretion systems inject effector proteins into eukaryotic host cells in order to promote survival and colonization of Gram-negative pathogens and symbionts. Secretion across the bacterial cell envelope and injection into host cells is facilitated by a so-called injectisome. Its small hydrophobic export apparatus components SpaP and SpaR were shown to nucleate assembly of the needle complex and to form the central "cup" substructure of a Salmonella Typhimurium secretion system. However, the in vivo placement of these components in the needle complex and their function during the secretion process remained poorly defined. Here we present evidence that a SpaP pentamer forms a 15 Å wide pore and provide a detailed map of SpaP interactions with the export apparatus components SpaQ, SpaR, and SpaS. We further refine the current view of export apparatus assembly, consolidate transmembrane topology models for SpaP and SpaR, and present intimate interactions of the periplasmic domains of SpaP and SpaR with the inner rod protein PrgJ, indicating how export apparatus and needle filament are connected to create a continuous conduit for substrate translocation.

  18. Vitamin D, carotid intima-media thickness and bone structure in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Winckler, Karoline; Tarnow, Lise; Lundby-Christensen, Louise

    2015-01-01

    with osteoporosis. A 25(OH)D level was not associated with carotid IMT or arterial stiffness (P>0.3) or bone health (P>0.6) after adjustment for CVD risk factors. In conclusion, 25(OH)D status was not associated with carotid IMT, arterial stiffness or bone health in this cohort of patients with T2D. To explore......Despite aggressive treatment of cardiovascular disease (CVD) risk factors individuals with type 2 diabetes (T2D) still have increased risk of cardiovascular morbidity and mortality. The primary aim of this study was to examine the cross-sectional association between total (25-hydroxy vitamin D (25......(OH)D)) and risk of CVD in patients with T2D. Secondary objective was to examine the association between 25(OH)D and bone health. A Danish cohort of patients with T2D participating in a randomised clinical trial were analysed. In total 415 patients (68% men, age 60±9 years (mean±s.d.), duration...

  19. Structures and efficiency areas of object control systems with various types of recycling

    Science.gov (United States)

    Myshlyaev, L. P.; Tsyryapkina, A. V.; Burkov, V. N.; Ivushkin, K. A.

    2017-09-01

    The work is devoted to the study of automatic control systems (ACS) of objects with various types of recycling. The characteristic feature of such objects is the presence of a delay element in the coordinates. It is known that only with the help of recycling the use of raw materials and energy resources can be maximized. However, little attention has been paid to the control of such objects in the well-known publications, which gives the study a particular importance. The paper describes a classification of objects with recycling proposed by the authors with the identification of four classes of objects: recycling “by concentration”, “by mass”, “by parameters”, combined recycling. ACS are synthesized for the first three classes of objects. The task of comparative analysis of the systems effectiveness with a model control law and the proposed synthesized systems is set, as well as the task of determination of areas of systems effective operation depending on the variable value of the ratio of the delay time in the recycling chain and in the direct circuit, the conclusions are drawn.

  20. Molecular Analysis of the Coprinus Cinereus Mating Type a Factor Demonstrates an Unexpectedly Complex Structure

    Science.gov (United States)

    May, G.; Chevanton, L. L.; Pukkila, P. J.

    1991-01-01

    We report here the molecular cloning of the A43 mating type factor from Coprinus cinereus, a basidiomycetous fungus. Our molecular analyses revealed an unexpected source of variation in the A factor. Though genetic studies have demonstrated that A has two subunits, α and β, we located three nonoverlapping fragments in the A43 region that have A factor function following DNA-mediated transformation. The three fragments demonstrate no similarity to one another as judged by restriction enzyme maps and by hybridization on Southern blots. We conclude that the A43 factor is composed of at least three subunits. When strains carrying different A factors are examined by hybridization to the cloned subunits, extensive polymorphism is seen. Both intensity of hybridization and restriction fragment lengths vary between strains. Some strains fail to show any hybridization to a probe. In contrast, other strains from widely separated geographic locations apparently share very similar subunits. From comparative restriction enzyme mapping of A43 and a mutated A43 factor, we inferred that a 12-kb deletion in the A factor was responsible for the constitutive, dominant phenotype of the mutated A factor. The results of transformation experiments support an activator model for the activity of the A factor in regulating the A pathway. PMID:1678725

  1. Influence of strain on local structure and lithium ionic conduction in garnet-type solid electrolyte

    Science.gov (United States)

    Yamada, Hirotoshi; Ito, Tomoko; Hongahally Basappa, Rajendra; Bekarevich, Raman; Mitsuishi, Kazutaka

    2017-11-01

    All-solid-state batteries (ASSBs) have various problems associated with their usage that are normally not encountered in conventional lithium-ion batteries. Stress on interfaces between solid electrolytes and active materials is one of the key issues because the active materials change their volume during charging/discharging. In this work, first, we reveal that garnet-type solid electrolytes, Li6.5La3Zr1.5Ta0.5O12 (LLZT), prepared by the spark plasma sintering (SPS) technique, exhibit a residual tensile stress of more than 100 MPa in the direction of the SPS pressure. Then, the influence of the strain on ionic conduction is investigated in detail. It is demonstrated that the strain causes no change in the bulk resistance, while the grain boundary resistance increases in both the pre-exponential factor and the activation energy. The results suggest the importance of the strength of grain boundaries (including interfaces) for the practical application of ASSBs.

  2. An Active Heater Control Concept to Meet IXO Type Mirror Module Thermal-Structural Distortion Requirement

    Science.gov (United States)

    Choi, Michael

    2013-01-01

    Flight mirror assemblies (FMAs) of large telescopes, such as the International X-ray Observatory (IXO), have very stringent thermal-structural distortion requirements. The spatial temperature gradient requirement within a FMA could be as small as 0.05 C. Con ventionally, heaters and thermistors are attached to the stray light baffle (SLB), and centralized heater controllers (i.e., heater controller boards located in a large electronics box) are used. Due to the large number of heater harnesses, accommodating and routing them is extremely difficult. The total harness length/mass is very large. This innovation uses a thermally conductive pre-collimator to accommodate heaters and a distributed heater controller approach. It minimizes the harness length and mass, and reduces the problem of routing and accommodating them. Heaters and thermistors are attached to a short (4.67 cm) aluminum portion of the pre-collimator, which is thermally coupled to the SLB. Heaters, which have a very small heater power density, and thermistors are attached to the exterior of all the mirror module walls. The major portion (23.4 cm) of the pre-collimator for the middle and outer modules is made of thin, non-conductive material. It minimizes the view factors from the FMA and heated portion of the precollimator to space. It also minimizes heat conduction from one end of the FMA to the other. Small and multi-channel heater controllers, which have adjustable set points and internal redundancy, are used. They are mounted to the mechanical support structure members adjacent to each module. The IXO FMA, which is 3.3 m in diameter, is an example of a large telescope. If the heater controller boards are centralized, routing and accommodating heater harnesses is extremely difficult. This innovation has the following advantages. It minimizes the length/mass of the heater harness between the heater controllers and heater circuits. It reduces the problem of routing and accommodating the harness on the

  3. Effect of surfactant types and their concentration on the structural characteristics of nanoclay

    Science.gov (United States)

    Zawrah, M. F.; Khattab, R. M.; Saad, E. M.; Gado, R. A.

    2014-03-01

    A series of organo-modified nanoclays was synthesized using three different surfactants having different alkyl chain lengths and concentrations [0.5-5.0 cation exchange capacity (CEC)]. These surfactants were Ethanolamine (EA), Cetyltrimethylammoniumbromide (CTAB) and Tetraoctadecylammoniumbromide (TO). The obtained modified nanoclays were characterized by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) and compared with unmodified nanoclay. The results of XRD analysis indicated that the basal d-spacing has increased with increasing alkyl chain length and surfactant concentration. From the obtained microstructures of these organo-modified nanoclays, the mechanism of surfactant adsorption was proposed. At relatively low loading of surfactant, most of surfactant entered the spacing by an ion-exchange mechanism and is adsorbed onto the interlayer cation sites. When the concentration of the surfactant exceeds the CEC of clay, the surfactant molecules then adhere to the surface adsorbed surfactant. Some surfactants entered the interlayers, whereas the others were attached to the clay surface. When the concentration of surfactant increased further beyond 2.0 CEC, the surfactants might occupy the inter-particle space within the house-of-cards aggregate structure.

  4. Structure of the macrozoobenthos as an indicator of different types of pollution in running waters

    Directory of Open Access Journals (Sweden)

    Simić Vladica M.

    2002-01-01

    Full Text Available Hydrobiological research on streams with different dominant forms of pollution (anthropogenic eutrophication, organic pollution, toxic pollution, trans-saprobic pollution in the central part of the Balkan Peninsula (territory of Serbia and Montenegro indicates that these different forms of pollution can be detected on the basis of structure of the macrozoobenthos community and individual indicator taxa. It is established from the obtained results that the greatest community diversity occurs in the case of anthropogenic eutrophication or weak organic pollution as a dominant process, where phytophilous and/or detritophagic forms (Cloeon, Polypedilum, Asellus, Stylaria, Erpobdella, Gammarus are dominant in the community. In the cases of very strong organic pollution, the macrozoobenthos community is characterized by mass development of certain taxa of the group Oligochaeta (Tubificidae and Chironomidae larvae {Chironomus gr. thummi. Depending on the strength and contribution of organic, toxic, and/or transsaprobic components, toxic pollution and mixed pollution arc characterized by a more or less heterogeneous and nonspecific population. However, a common feature is the presence of a small number of taxa with populations of a relatively low density, or the occurrence of individual specimens belonging to different groups of animals.

  5. A comparative study on electronic and structural properties of transition metal monosilicides, CrSi(B20-type), RhSi(B20-type), RhSi(B31-type) and RhSi(B2-type)

    Science.gov (United States)

    Altintas, Bahadir

    2011-11-01

    Transition metal based monosilicide compounds (CrSi and RhSi) have been investigated theoretically from ab initio calculations. The structural and electronic band calculations of CrSi and different phases of RhSi crystals show that the metallic property and hypothetically constructed structures of RhSi(Pnma) under different pressures from 0 GPa to 75 GPa show a certain difference only along Γ-Z directions of the high symmetry points of first Brillouin zone. The character of the bands around fermi level was determined by partial density of state calculations.

  6. Structural effect of monomer type on properties of copolyimides and copolyimide-silica hybrid materials

    Directory of Open Access Journals (Sweden)

    Kizilkaya Canan

    2015-01-01

    Full Text Available In this work, the effect of two different diamine monomers, containing phosphine oxide, on thermal, mechanical and morphological properties of copolyimides and their hybrid materials was investigated. Gas separation properties of the synthesized copolyimides were also analysed. Two different diamine monomers with phosphine oxide were bis(3-aminophenyl phenylphosphine oxide (BAPPO and bis(3-aminophenoxy-4-phenyl phenylphosphine oxide (m-BAPPO. In the synthesis of copolyimides 3,3’-diamino-diphenyl sulfone (DDS was also used as the diamine, as well as 2,2’-bis(3,4-dicarboxyphenylhexafluoropropane dianhydride (6FDA. Copolyimide films were prepared by thermal imidization. Hybrid materials containing 5 % SiO2 were synthesised further by sol-gel technique. The Fourier-transform infrared spectroscopy (FTIR, Nuclear magnetic resonance spectroscopy (NMR confirmed the expected structure. Dynamic mechanical analysis (DMA demonstrated that m-BAPPO based copolyimides had lower glass transition temperatures (Tg than BAPPO based copolyimides. m-BAPPO containing copolyimide without silica shifted the thermal decomposition temperature to a higher value. The moduli and strength values of BAPPO diamine containing copolyimide and its hybrid were higher than those of m-BAPPO containing materials. The contact angle measurements showed the hydrophobicity. Scanning electron microscope (SEM analysis exhibited the silica particles dispersion in the copolyimides. These copolyimides may be used in the coating industry. The CO2 permeability and the permselectivity were the highest among the other values in this study, when m-BAPPO containing copolyimide in the absence of silica was used. The gas permeabilities obtained from this work were in this decreasing order: PCO2 > PO2 > PN2.

  7. Structural, microstructural and electrochemical properties of dispersed-type polymer nanocomposite films

    Science.gov (United States)

    Arya, Anil; Sharma, A. L.

    2018-01-01

    Free-standing solid polymer nanocomposite (PEO–PVC)  +  LiPF6-TiO2 films have been prepared through a standard solution-cast technique. The improvement in structural, microstructural and electrochemical properties has been observed on the dispersion of nanofiller in polymer salt complex. X-ray diffraction studies clearly reflect the formation of complex formation, as no corresponding salt peak appeared in the diffractograms. The Fourier transform infrared analysis suggested clear and convincing evidence of polymer–ion, ion–ion and polymer–ion-nanofiller interaction. The highest ionic conductivity of the prepared solid polymer electrolyte (SPE) films is ~5  ×  10‑5 S cm‑1 for 7 wt.% TiO2. The linear sweep voltammetry provides the electrochemical stability window of the prepared SPE films, about ~3.5 V. The ion transference number has been estimated, t ion  =  0.99 through the DC polarization technique. Dielectric spectroscopic studies were performed to understand the ion transport process in polymer electrolytes. All solid polymer electrolytes possess good thermal stability up to 300 °C. Differential scanning calorimetry analysis confirms the decrease of the melting temperature and signal of glass transition temperature with the addition of nanofiller, which indicates the decrease of crystallinity of the polymer matrix. An absolute correlation between diffusion coefficient (D), ion mobility (µ), number density (n), double-layer capacitance (C dl), glass transition temperature, melting temperature (T m), free ion area (%) and conductivity (σ) has been observed. A convincing model to study the role of nanofiller in a polymer salt complex has been proposed, which supports the experimental findings. The prepared polymer electrolyte system with significant ionic conductivity, high ionic transference number, and good thermal and voltage stability could be suggested as a potential candidate as electrolyte cum separator for the

  8. Statistical aspects of discerning indel-type structural variation via DNA sequence alignment

    Directory of Open Access Journals (Sweden)

    Wilson Richard K

    2009-08-01

    Full Text Available Abstract Background Structural variations in the form of DNA insertions and deletions are an important aspect of human genetics and especially relevant to medical disorders. Investigations have shown that such events can be detected via tell-tale discrepancies in the aligned lengths of paired-end DNA sequencing reads. Quantitative aspects underlying this method remain poorly understood, despite its importance and conceptual simplicity. We report the statistical theory characterizing the length-discrepancy scheme for Gaussian libraries, including coverage-related effects that preceding models are unable to account for. Results Deletion and insertion statistics both depend heavily on physical coverage, but otherwise differ dramatically, refuting a commonly held doctrine of symmetry. Specifically, coverage restrictions render insertions much more difficult to capture. Increased read length has the counterintuitive effect of worsening insertion detection characteristics of short inserts. Variance in library insert length is also a critical factor here and should be minimized to the greatest degree possible. Conversely, no significant improvement would be realized in lowering fosmid variances beyond current levels. Detection power is examined under a straightforward alternative hypothesis and found to be generally acceptable. We also consider the proposition of characterizing variation over the entire spectrum of variant sizes under constant risk of false-positive errors. At 1% risk, many designs will leave a significant gap in the 100 to 200 bp neighborhood, requiring unacceptably high redundancies to compensate. We show that a few modifications largely close this gap and we give a few examples of feasible spectrum-covering designs. Conclusion The theory resolves several outstanding issues and furnishes a general methodology for designing future projects from the standpoint of a spectrum-wide constant risk.

  9. [Antigenic polysaccharides of bacteria: 41. Structures of the O-specific polysaccharides of Shigella dysenteriae types 4 and 5 revised by NMR spectroscopy].

    Science.gov (United States)

    Perepelov, A V; Senchenkova, S N; Shashkov, A S; Knirel', Iu A; Liu, B; Feng, L; Wang, L

    2008-01-01

    The earlier established structures of the acidic O-specific polysaccharides from two typical strains of the Shigella dysenteriae bacterium were revised using modern NMR spectroscopy techniques. In particular, the configurations of the glycosidic linkages of GlcNAc (S. dysenteriae type 4) and mannose (S. dysenteriae type 5) residues were corrected. In addition, the location of the sites of nonstoichiometric O-acetylation in S. dysenteriae type 4 was determined: the lateral fucose residue was shown to be occasionally O-acetylated; also, the position of the O-acetyl group present at the stoichiometric quantity in S. dysenteriae type 5 was corrected. The revised structures of the polysaccharides studied are shown below. The known identity of the O-specific polysaccharide structures of S. dysenteriae type 5 and Escherichia coli O58 was confirmed by 13C NMR spectroscopy and, hence, the structure of the E. coli O58 polysaccharide should be revised in the same manner. [Formula: see text].

  10. A working hypothesis for broadening framework types of zeolites in seed-assisted synthesis without organic structure-directing agent.

    Science.gov (United States)

    Itabashi, Keiji; Kamimura, Yoshihiro; Iyoki, Kenta; Shimojima, Atsushi; Okubo, Tatsuya

    2012-07-18

    Recent research has demonstrated a new synthesis route to useful zeolites such as beta, RUB-13, and ZSM-12 via seed-assisted, organic structure-directing agent (OSDA)-free synthesis, although it had been believed that these zeolites could be essentially synthesized with OSDAs. These zeolites are obtained by adding seeds to the gels that otherwise yield other zeolites; however, the underlying crystallization mechanism has not been fully understood yet. Without any strategy, it is unavoidable to employ a trial-and-error procedure for broadening zeolite types by using this synthesis method. In this study, the effect of zeolite seeds with different framework structures is investigated to understand the crystallization mechanism of zeolites obtained by the seed-assisted, OSDA-free synthesis method. It has been found that the key factor in the successful synthesis of zeolites in the absence of OSDA is the common composite building unit contained both in the seeds and in the zeolite obtained from the gel after heating without seeds. A new working hypothesis for broadening zeolite types by the seed-assisted synthesis without OSDA is proposed on the basis of the findings of the common composite building units in zeolites. This hypothesis enables us to design the synthesis condition of target zeolites. The validity of the hypothesis is experimentally tested and verified by synthesizing several zeolites including ECR-18 in K-aluminosilicate system.

  11. Determination of kinetics and crystal structure of a novel Type 2 Isopentenyl Diphosphate: Dimethylallyl Diphosphate Isomerase from Streptococcus pneumoniae

    Science.gov (United States)

    de Ruyck, Jerome; Janczak, Matthew W.; Neti, Syam Sundar; Rothman, Steven C.; Schubert, Heidi L.; Cornish, Rita M.; Matagne, Andre; Wouters, Johan; Poulter, C. Dale

    2014-01-01

    Isopentenyl diphosphate dimethylallyl diphosphate isomerase (IDI) is a key enzyme in the isoprenoid biosynthetic pathway and is required for all organisms that synthesize isoprenoid metabolites from mevalonate. Type 1 IDI (IDI-1) is a metalloprotein and is found in eukaryotes, while the type-2 isoform (IDI-2) is a flavoenzyme found in bacteria and completely absent from human. IDI-2 from the pathogenic bacterium Streptococcus pneumoniae was recombinantly expressed in E. coli. Steady state kinetic studies of the enzyme indicated that FMNH2 (KM= 0.3 μM) bound before isopentenyl diphosphate (KM= 40 μM) in an ordered binding mechanism. An X-ray crystal structure at 1.4 Å resolution was obtained for the holo-enzyme, in the closed conformation with reduced flavin cofactor and two sulfate ions in the active site. These results helped to further approach the enzymatic mechanism of IDI-2 and, thus, open new possibilities for the rational design of antibacterial compounds against closely sequence and structure related pathogens such as E. faecalis or S. aureus. PMID:24910111

  12. Synthesis and electronic structure of proton-type partially substituted birnessite by period-four transition metal

    Energy Technology Data Exchange (ETDEWEB)

    Takei, Takahiro, E-mail: takei@yamanashi.ac.jp [Center for Crystal Science and Technology, University of Yamanashi, 7-32 Miyamae, Kofu, Yamanashi 400-8511 (Japan); Dong, Qiang; Yonesaki, Yoshinori; Kumada, Nobuhiro; Kinomura, Nobukazu [Center for Crystal Science and Technology, University of Yamanashi, 7-32 Miyamae, Kofu, Yamanashi 400-8511 (Japan)

    2011-11-15

    Highlights: {yields} Partial metal substitutions of birnessite result in three types of crystal structure. {yields} Rhombohedral, monoclinic and hexagonal phase emerged in the substituted birnessite. {yields} The electrical conductivity decreased by substitution of transition metal for Mn. {yields} Partially substitution by Fe, Co and Ni poses splitting of crystal field for MnO{sub 6}. -- Abstract: Partially substituted proton-type birnessite were prepared by solid state reaction and their structures were refined. The formed birnessite with no substitution is identified to rhombohedral phase. In the case of substitution treatment by V and Cr for Mn, birnessite phase was not formed. On substituting Fe, hexagonal phase increased with increase of the amount of the Fe. For Co and Ni-substitution, monoclinic phase emerged at substitution ratio of around 0.37 and 0.02, respectively. For the substitution of Cu, only the monoclinic birnessite formed irrespective of the ratio. The electric conductivity of the partially substituted birnessites was examined at room temperature. The general trend is lower conductivity with increasing ratio of contained substituents. On several mol% of the substitution by Ni and Cu, the conductivity slightly increased. From DOS calculation of these compounds, the partially substitution for Mn by Fe, Co and Ni in the birnessite poses splitting of crystal field to emerge new bands at around -1 and +1 eV by Mn(IV) 3d orbital.

  13. A Comparative Structure/Function Analysis of Two Type IV Pilin DNA Receptors Defines a Novel Mode of DNA Binding.

    Science.gov (United States)

    Berry, Jamie-Lee; Xu, Yingqi; Ward, Philip N; Lea, Susan M; Matthews, Stephen J; Pelicic, Vladimir

    2016-06-07

    DNA transformation is a widespread process allowing bacteria to capture free DNA by using filamentous nano-machines composed of type IV pilins. These proteins can act as DNA receptors as demonstrated by the finding that Neisseria meningitidis ComP minor pilin has intrinsic DNA-binding ability. ComP binds DNA better when it contains the DNA-uptake sequence (DUS) motif abundant in this species genome, playing a role in its trademark ability to selectively take up its own DNA. Here, we report high-resolution structures for meningococcal ComP and Neisseria subflava ComPsub, which recognize different DUS motifs. We show that they are structurally identical type IV pilins that pack readily into filament models and display a unique DD region delimited by two disulfide bonds. Functional analysis of ComPsub defines a new mode of DNA binding involving the DD region, adapted for exported DNA receptors. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  14. A new type of coil structure called pan-shaped coil of wireless charging system based on magnetic resonance

    Science.gov (United States)

    Yue, Z. K.; Liu, Z. Z.; Hou, Y. J.; Zeng, H.; Liang, L. H.; Cui, S.

    2017-11-01

    The problem that misalignment between the transmitting coil and the receiving coil significantly impairs the transmission power and efficiency of the system has been attached more and more attention. In order to improve the uniformity of the magnetic field between the two coils to solve this problem, a new type of coil called pan-shaped coil is proposed. Three-dimension simulation models of the planar-core coil and the pan-shaped coil are established using Ansoft Maxwell software. The coupling coefficient between the transmitting coil and the receiving coil is obtained by simulating the magnetic field with the receiving coil misalignment or not. And the maximum percentage difference strength along the radial direction which is defined as the magnetic field uniformity factor is calculated. According to the simulation results of the two kinds of coil structures, it is found that the new type of coil structure can obviously improve the uniformity of the magnetic field, coupling coefficient and power transmission properties between the transmitting coil and the receiving coil.

  15. MIn(HAsO42 (M = K, Rb, Cs: three new hydrogenarsenates adopting two different structure types

    Directory of Open Access Journals (Sweden)

    Karolina Schwendtner

    2017-10-01

    Full Text Available Potassium indium bis[hydrogen arsenate(V], KIn(HAsO42, rubidium indium bis[hydrogen arsenate(V], RbIn(HAsO42, and caesium indium bis[hydrogen arsenate(V], CsIn(HAsO42, were grown under mild hydrothermal conditions (T = 493 K, 7–8 d. KIn(HAsO42 adopts the KSc(HAsO42 structure type (space group C2/c, while RbIn(HAsO42 and CsIn(HAsO42 crystallize in the space group R-3c and are the first arsenate representatives of the RbFe(HPO42 structure type. All three compounds have tetrahedral–octahedral framework topologies. The M+ cations, located in voids of the respective framework, are slightly disordered in RbIn(HAsO42. In KIn(HAsO42, there is a second K-atom position with a very low occupancy, which may suggest that the K atom can easily move in the channels extending along [101].

  16. Determination of kinetics and the crystal structure of a novel type 2 isopentenyl diphosphate: dimethylallyl diphosphate isomerase from Streptococcus pneumoniae.

    Science.gov (United States)

    de Ruyck, Jerome; Janczak, Matthew W; Neti, Syam Sundar; Rothman, Steven C; Schubert, Heidi L; Cornish, Rita M; Matagne, Andre; Wouters, Johan; Poulter, C Dale

    2014-07-07

    Isopentenyl diphosphate isomerase (IDI) is a key enzyme in the isoprenoid biosynthetic pathway and is required for all organisms that synthesize isoprenoid metabolites from mevalonate. Type 1 IDI (IDI-1) is a metalloprotein that is found in eukaryotes, whereas the type 2 isoform (IDI-2) is a flavoenzyme found in bacteria that is completely absent from human. IDI-2 from the pathogenic bacterium Streptococcus pneumoniae was recombinantly expressed in Escherichia coli. Steady-state kinetic studies of the enzyme indicated that FMNH2 (KM =0.3 μM) bound before isopentenyl diphosphate (KM =40 μM) in an ordered binding mechanism. An X-ray crystal structure at 1.4 Å resolution was obtained for the holoenzyme in the closed conformation with a reduced flavin cofactor and two sulfate ions in the active site. These results helped to further approach the enzymatic mechanism of IDI-2 and, thus, open new possibilities for the rational design of antibacterial compounds against sequence-similar and structure-related pathogens such as Enterococcus faecalis or Staphylococcus aureus. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Structural studies of n-type nc-Si-QD thin films for nc-Si solar cells

    Science.gov (United States)

    Das, Debajyoti; Kar, Debjit

    2017-12-01

    A wide optical gap nanocrystalline silicon (nc-Si) dielectric material is a basic requirement at the n-type window layer of nc-Si solar cells in thin film n-i-p structure on glass substrates. Taking advantage of the high atomic-H density inherent to the planar inductively coupled low-pressure (SiH4 + CH4)-plasma, development of an analogous material in P-doped nc-Si-QD/a-SiC:H network has been tried. Incorporation of C in the Si-network extracted from the CH4 widens the optical band gap; however, at enhanced PH3-dilution of the plasma spontaneous miniaturization of the nc-Si-QDs below the dimension of Bohr radius (∼4.5 nm) further enhances the band gap by virtue of the quantum size effect. At increased flow rate of PH3, dopant induced continuous amorphization of the intrinsic crystalline network is counterbalanced by the further crystallization promoted by the supplementary atomic-H extracted from PH3 (1% in H2) in the plasma, eventually holding a moderately high degree of crystallinity. The n-type wide band gap (∼1.93 eV) window layer with nc-Si-QDs in adequate volume fraction (∼52%) could furthermore be instrumental as an effective seed layer for advancing sequential crystallization in the i-layer of nc-Si solar cells with n-i-p structure in superstrate configuration.

  18. [Effects of three types of veneering porcelain on bending strength of KAVO(TM) Y-TZP/porcelain bilayered structure].

    Science.gov (United States)

    Ma, Ting-ting; Yi, Yuan-fu; Shao, Long-quan; Tian, Jie-mo; Hou, Kang-lin; Zhang, Wei-wei; Wen, Ning; Deng, Bin

    2010-10-01

    To investigate the effect of three types of veneering porcelain on the bending strength of KAVO Y-TZP/porcelain layered structure. KAVO zirconia ceramics were used as the substructure. To form Y-TZP/porcelain bilayered structure, a leucite-based veneering porcelain was fired on the zirconia substructures by slip-casting technique with dentin washbake, and two nano-fluorapatite-based veneering porcelains were fired on the zirconia substructures by either slip-casting or pressed-on technique with or without liner coverage. The bending strength was tested according to ISO 6872 standard, and the veneered surfaces of the fracture samples were analyzed by scanning electron microscopy (SEM). For covering KAVO zirconia core material, the conventional veneering slurry-porcelain combined with liner or wash firing had significant higher bending strength than pressed-on porcelain. SEM showed that the main failure type at the interface was adhesive failure. Thin layer sintering using washbake program or liner on KAVO zirconia surface increases the surface wettability, and this procedure may be indispensable when veneering on the surface of dental zirconia.

  19. Three-Dimensional Gene Map of Cancer Cell Types: Structural Entropy Minimisation Principle for Defining Tumour Subtypes

    Science.gov (United States)

    Li, Angsheng; Yin, Xianchen; Pan, Yicheng

    2016-02-01

    In this study, we propose a method for constructing cell sample networks from gene expression profiles, and a structural entropy minimisation principle for detecting natural structure of networks and for identifying cancer cell subtypes. Our method establishes a three-dimensional gene map of cancer cell types and subtypes. The identified subtypes are defined by a unique gene expression pattern, and a three-dimensional gene map is established by defining the unique gene expression pattern for each identified subtype for cancers, including acute leukaemia, lymphoma, multi-tissue, lung cancer and healthy tissue. Our three-dimensional gene map demonstrates that a true tumour type may be divided into subtypes, each defined by a unique gene expression pattern. Clinical data analyses demonstrate that most cell samples of an identified subtype share similar survival times, survival indicators and International Prognostic Index (IPI) scores and indicate that distinct subtypes identified by our algorithms exhibit different overall survival times, survival ratios and IPI scores. Our three-dimensional gene map establishes a high-definition, one-to-one map between the biologically and medically meaningful tumour subtypes and the gene expression patterns, and identifies remarkable cells that form singleton submodules.

  20. Influence of reinforcement type on the mechanical behavior and fire response of hybrid composites and sandwich structures

    Science.gov (United States)

    Giancaspro, James William

    Lightweight composites and structural sandwich panels are commonly used in marine and aerospace applications. Using carbon, glass, and a host of other high strength fiber types, a broad range of laminate composites and sandwich panels can be developed. Hybrid composites can be constructed by laminating multiple layers of varying fiber types while sandwich panels are manufactured by laminating rigid fiber facings onto a lightweight core. However, the lack of fire resistance of the polymers used for the fabrication remains a very important problem. The research presented in this dissertation deals with an inorganic matrix (Geopolymer) that can be used to manufacture laminate composites and sandwich panels that are resistant up to 1000°C. This dissertation deals with the influence of fiber type on the mechanical behavior and the fire response of hybrid composites and sandwich structures manufactured using this resin. The results are categorized into the following distinct studies. (i) High strength carbon fibers were combined with low cost E-glass fibers to obtain hybrid laminate composites that are both economical and strong. The E-glass fabrics were used as a core while the carbon fibers were placed on the tension face and on both tension and compression faces. (ii) Structural sandwich beams were developed by laminating various types of reinforcement onto the tension and compression faces of balsa wood cores. The flexural behavior of the beams was then analyzed and compared to beams reinforced with organic composite. The effect of core density was evaluated using oak beams reinforced with inorganic composite. (iii) To measure the fire response, balsa wood sandwich panels were manufactured using a thin layer of a fire-resistant paste to serve for fire protection. Seventeen sandwich panels were fabricated and tested to measure the heat release rates and smoke-generating characteristics. The results indicate that Geopolymer can be effectively used to fabricate both

  1. Myotonic Dystrophy Type 1 RNA Crystal Structures Reveal Heterogeneous 1 × 1 Nucleotide UU Internal Loop Conformations

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Amit; Park, HaJeung; Fang, Pengfei; Parkesh, Raman; Guo, Min; Nettles, Kendall W.; Disney, Matthew D. (Scripps)

    2012-03-27

    RNA internal loops often display a variety of conformations in solution. Herein, we visualize conformational heterogeneity in the context of the 5'CUG/3'GUC repeat motif present in the RNA that causes myotonic dystrophy type 1 (DM1). Specifically, two crystal structures of a model DM1 triplet repeating construct, 5'r[{und UU}GGGC(C{und U}G){sub 3}GUCC]{sub 2}, refined to 2.20 and 1.52 {angstrom} resolution are disclosed. Here, differences in the orientation of the 5' dangling UU end between the two structures induce changes in the backbone groove width, which reveals that noncanonical 1 x 1 nucleotide UU internal loops can display an ensemble of pairing conformations. In the 2.20 {angstrom} structure, CUGa, the 5' UU forms a one hydrogen-bonded pair with a 5' UU of a neighboring helix in the unit cell to form a pseudoinfinite helix. The central 1 x 1 nucleotide UU internal loop has no hydrogen bonds, while the terminal 1 x 1 nucleotide UU internal loops each form a one-hydrogen bond pair. In the 1.52 {angstrom} structure, CUGb, the 5' UU dangling end is tucked into the major groove of the duplex. While the canonically paired bases show no change in base pairing, in CUGb the terminal 1 x 1 nucleotide UU internal loops now form two hydrogen-bonded pairs. Thus, the shift in the major groove induced by the 5' UU dangling end alters noncanonical base patterns. Collectively, these structures indicate that 1 x 1 nucleotide UU internal loops in DM1 may sample multiple conformations in vivo. This observation has implications for the recognition of this RNA, and other repeating transcripts, by protein and small molecule ligands.

  2. Structural basis for type VI secreted peptidoglycan dl-endopeptidase function, specificity and neutralization in Serratia marcescens

    Energy Technology Data Exchange (ETDEWEB)

    Srikannathasan, Velupillai; English, Grant [University of Dundee, Dundee DD1 5EH, Scotland (United Kingdom); Bui, Nhat Khai [Newcastle University, Newcastle upon Tyne NE2 4HH (United Kingdom); Trunk, Katharina; O’Rourke, Patrick E. F.; Rao, Vincenzo A. [University of Dundee, Dundee DD1 5EH, Scotland (United Kingdom); Vollmer, Waldemar [Newcastle University, Newcastle upon Tyne NE2 4HH (United Kingdom); Coulthurst, Sarah J., E-mail: s.j.coulthurst@dundee.ac.uk; Hunter, William N., E-mail: s.j.coulthurst@dundee.ac.uk [University of Dundee, Dundee DD1 5EH, Scotland (United Kingdom)

    2013-12-01

    Crystal structures of type VI secretion system-associated immunity proteins, a peptidoglycan endopeptidase and a complex of the endopeptidase and its cognate immunity protein are reported together with assays of endopeptidase activity and functional assessment. Some Gram-negative bacteria target their competitors by exploiting the type VI secretion system to extrude toxic effector proteins. To prevent self-harm, these bacteria also produce highly specific immunity proteins that neutralize these antagonistic effectors. Here, the peptidoglycan endopeptidase specificity of two type VI secretion-system-associated effectors from Serratia marcescens is characterized. These small secreted proteins, Ssp1 and Ssp2, cleave between γ-d-glutamic acid and l-meso-diaminopimelic acid with different specificities. Ssp2 degrades the acceptor part of cross-linked tetratetrapeptides. Ssp1 displays greater promiscuity and cleaves monomeric tripeptides, tetrapeptides and pentapeptides and dimeric tetratetra and tetrapenta muropeptides on both the acceptor and donor strands. Functional assays confirm the identity of a catalytic cysteine in these endopeptidases and crystal structures provide information on the structure–activity relationships of Ssp1 and, by comparison, of related effectors. Functional assays also reveal that neutralization of these effectors by their cognate immunity proteins, which are called resistance-associated proteins (Raps), contributes an essential role to cell fitness. The structures of two immunity proteins, Rap1a and Rap2a, responsible for the neutralization of Ssp1 and Ssp2-like endopeptidases, respectively, revealed two distinct folds, with that of Rap1a not having previously been observed. The structure of the Ssp1–Rap1a complex revealed a tightly bound heteromeric assembly with two effector molecules flanking a Rap1a dimer. A highly effective steric block of the Ssp1 active site forms the basis of effector neutralization. Comparisons with Ssp2–Rap2

  3. IMPROVING THE UNDERSTANDING OF THE CONCEPT AND STUDENT LEARNING ACTIVITIES USED COOPERATIVE LEARNING MODEL TYPE STAD BASED STRUCTURED LKS

    Directory of Open Access Journals (Sweden)

    Elisa .

    2013-06-01

    Full Text Available The objective in this research to improve understanding of the concepts and learning activity of students in solving physics problems through learning models of Cooperative type STAD based structured worksheet. The subjects were first grade students of SMA Swasta Galih Agung numbered 21 people consisted of 21 girls. Object of research is a process of learning by applying Cooperative type STAD model of learning. The research method was applied action research through two learning cycles, each cycle consisting of the stages of planning, implementation, observation and reflection. The results of the data analysis shown that through the application of Cooperative type STAD based structured worksheet model of learning there is an increasing mastery of physics concepts and learning activity first grade students. Increased mastery of physics concepts is seen from increase the number of students who pass out of 10 students (47,62% to 18 students (85,7% with averages of 66,62 and 81,09, the learning outcomes completeness criteria of a minimum of 65. Increasing students' learning activity was view from the first and second cycles includes Visual with an average of 81,90% to 91,42%, Oral with an average of 80% to 87,90%, Listening with an average of 81,27% to 84,15%, Writing with an average of 78,08 to 85,41%, Motor with an average of 72,05% to 80%, Mental with an average of 71,44% to 82,20% and Emotional with an average of 73,03% to 82,24%.

  4. A novel land use approach for assessment of human health: The relationship between urban structure types and cardiorespiratory disease risk.

    Science.gov (United States)

    Réquia Júnior, Weeberb João; Roig, Henrique Llacer; Koutrakis, Petros

    2015-12-01

    Extensive evidence shows that in addition to lifestyle factors, environmental aspects are an important risk factor for human health. Numerous approaches have been used to estimate the relationship between environment and health. For example, the urban characteristics, especially the types of land use, are considered a potential proxy indicator to evaluate risk of disease. Although several studies have used land use variables to assess human health, none of them has used the concept of Urban Morphology by Urban Structure Types (USTs) as indicators of land use. The aim of this study was to assess the relationship between USTs and cardiorespiratory disease risks in the Federal District, Brazil. Toward this end, we used a quantile regression model to estimate risk. We used 21 types of UST. Income and population density were used as covariates in our sensitivity analysis. Our analysis showed an association between cardiorespiratory diseases risk and 10 UST variables (1 related to rural area, 6 related to residential area, 1 recreational area, 1 public area and 1 commercial area). Our findings suggest that the conventional land use method may be missing important information about the effect of land use on human health. The use of USTs can be an approach to complement the conventional method. This should be of interest to policy makers in order to enhance public health policies and to create future strategies in terms of urban planning, land use and environmental health. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Stellar Kinematics and Structural Properties of Virgo Cluster Dwarf Early-Type Galaxies from the SMAKCED Project

    Science.gov (United States)

    Toloba, Elisa; Guhathakurta, Puragra; Peletier, Reynier; Boselli, Alessandro; Lisker, Thorsten; Emsellem, Eric; Simon, Joshua D.; van de Ven, Glenn; Smakced Collaboration

    2015-01-01

    We analyze the stellar kinematics of 39 dwarf early-type galaxies (dEs) in the Virgo cluster. This is the largest survey conducted so far on spatially resolved kinematics of dEs. This sample is representative of the early-type population in the absolute magnitude range -19.0 high-pass filtered optical images, while the slow rotators do not exhibit these structures. In addition, two of the dEs have kinematically decoupled cores and four more have emission partially filling in the Balmer absorption lines. These properties suggest that Virgo cluster dEs may have originated from late-type star-forming galaxies that were transformed by the environment after their infall into the cluster. The correlation between the specific angular momentum and the clustercentric distance can be explained by a scenario where low luminosity star-forming galaxies fall into the cluster, their gas is rapidly removed by ram pressure stripping, although some of it can be retained in their core, their star-formation is quenched but their stellar kinematics are preserved. After a long time in the cluster and several passes through its center, the galaxies are heated up and transformed into slow rotating dEs.

  6. Structure-function relationships of different vascular bundle types in the stem of the Mexican fanpalm (Washingtonia robusta).

    Science.gov (United States)

    Rüggeberg, Markus; Speck, Thomas; Burgert, Ingo

    2009-01-01

    Structure and mechanics of fibre caps of different types of vascular bundles were studied at a certain height in the trunk of the palm Washingtonia robusta. By correlating these features with the distribution of the different bundle types across the trunk, possible strategies to cope with mechanical loads were elucidated. Micromechanical properties, cell parameters, microfibril orientation and lignification were studied using micromechanical testing, image analysis, synchrotron X-ray diffraction and UV-microspectrophotometry. The adjustment of stiffness followed a common principle in the fibre caps of all bundle types. Gradients in stiffness appeared across the caps in the centre of the trunk whereas stiffness remained high across the caps in the periphery of the trunk. The difference in stiffness profiles was interpreted as an adaptation to different mechanical constraints arising across the trunk. The gradual transition in stiffness prevents high local stress discontinuities between cap fibres and parenchyma and might be beneficial for trunk damping. At the periphery, the fibre caps without stiffness gradients contribute to a high flexural stiffness of the trunk as this has to be exclusively maintained by the material properties because geometric adjustments through increasing trunk diameter hardly occur in monocotyledonous palms.

  7. Structure and Biosynthesis of Branched Wax Compounds on Wild Type and Wax Biosynthesis Mutants of Arabidopsis thaliana.

    Science.gov (United States)

    Busta, Lucas; Jetter, Reinhard

    2017-06-01

    The cuticle is a waxy composite that protects the aerial organs of land plans from non-stomatal water loss. The chemical make-up of the cuticular wax mixture plays a central role in defining the water barrier, but structure-function relationships have not been established so far, in part due to gaps in our understanding of wax structures and biosynthesis. While wax compounds with saturated, linear hydrocarbon tails have been investigated in detail, very little is known about compounds with modified aliphatic tails, which comprise substantial portions of some plant wax mixtures. This study aimed to investigate the structures, abundances and biosynthesis of branched compounds on the species for which wax biosynthesis is best understood: Arabidopsis thaliana. Microscale derivatization, mass spectral interpretation and organic synthesis identified homologous series of iso-alkanes and iso-alcohols on flowers and leaves, respectively. These comprised approximately 10-15% of wild type wax mixtures. The abundances of both branched wax constituents and accompanying unbranched compounds were reduced on the cer6, cer3 and cer1 mutants but not cer4, indicating that branched compounds are in part synthesized by the same machinery as unbranched compounds. In contrast, the abundances of unbranched, but not branched, wax constituents were reduced on the cer2 and cer26 mutants, suggesting that the pathways to both types of compounds deviate in later steps of chain elongation. Finally, the abundances of branched, but not unbranched, wax compounds were reduced on the cer16 mutant, and the (uncharacterized) CER16 protein may therefore be controlling the relative abundances of iso-alkanes and iso-alcohols on Arabidopsis surfaces. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. Crystal Structure of a Bacterial Type IB DNA Topoisomerase Reveals a Preassembled Active Site in the Absence of DNA

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Asmita; Shuman, Stewart; Mondragon, Alfonso (NWU); (SKI)

    2010-03-08

    Type IB DNA topoisomerases are found in all eukarya, two families of eukaryotic viruses (poxviruses and mimivirus), and many genera of bacteria. They alter DNA topology by cleaving and resealing one strand of duplex DNA via a covalent DNA-(3-phosphotyrosyl)-enzyme intermediate. Bacterial type IB enzymes were discovered recently and are described as poxvirus-like with respect to their small size, primary structures, and bipartite domain organization. Here we report the 1.75-{angstrom} crystal structure of Deinococcus radiodurans topoisomerase IB (DraTopIB), a prototype of the bacterial clade. DraTopIB consists of an amino-terminal (N) {beta}-sheet domain (amino acids 1-90) and a predominantly {alpha}-helical carboxyl-terminal (C) domain (amino acids 91-346) that closely resemble the corresponding domains of vaccinia virus topoisomerase IB. The five amino acids of DraTopIB that comprise the catalytic pentad (Arg-137, Lys-174, Arg-239, Asn-280, and Tyr-289) are preassembled into the active site in the absence of DNA in a manner nearly identical to the pentad configuration in human topoisomerase I bound to DNA. This contrasts with the apoenzyme of vaccinia topoisomerase, in which three of the active site constituents are either displaced or disordered. The N and C domains of DraTopIB are splayed apart in an 'open' conformation, in which the surface of the catalytic domain containing the active site is exposed for DNA binding. A comparison with the human topoisomerase I-DNA cocrystal structure suggests how viral and bacterial topoisomerase IB enzymes might bind DNA circumferentially via movement of the N domain into the major groove and clamping of a disordered loop of the C domain around the helix.

  9. Structural insights into the redox-switch mechanism of the MarR/DUF24-type regulator HypR.

    Science.gov (United States)

    Palm, Gottfried J; Khanh Chi, Bui; Waack, Paul; Gronau, Katrin; Becher, Dörte; Albrecht, Dirk; Hinrichs, Winfried; Read, Randy J; Antelmann, Haike

    2012-05-01

    Bacillus subtilis encodes redox-sensing MarR-type regulators of the OhrR and DUF24-families that sense organic hydroperoxides, diamide, quinones or aldehydes via thiol-based redox-switches. In this article, we characterize the novel redox-sensing MarR/DUF24-family regulator HypR (YybR) that is activated by disulphide stress caused by diamide and NaOCl in B. subtilis. HypR controls positively a flavin oxidoreductase HypO that confers protection against NaOCl stress. The conserved N-terminal Cys14 residue of HypR has a lower pK(a) of 6.36 and is essential for activation of hypO transcription by disulphide stress. HypR resembles a 2-Cys-type regulator that is activated by Cys14-Cys49' intersubunit disulphide formation. The crystal structures of reduced and oxidized HypR proteins were resolved revealing structural changes of HypR upon oxidation. In reduced HypR a hydrogen-bonding network stabilizes the reactive Cys14 thiolate that is 8-9 Å apart from Cys49'. HypR oxidation breaks these H-bonds, reorients the monomers and moves the major groove recognition α4 and α4' helices ∼4 Å towards each other. This is the first crystal structure of a redox-sensing MarR/DUF24 family protein in bacteria that is activated by NaOCl stress. Since hypochloric acid is released by activated macrophages, related HypR-like regulators could function to protect pathogens against the host immune defense.

  10. Structure of a glycomimetic ligand in the carbohydrate recognition domain of C-type lectin DC-SIGN. Structural requirements for selectivity and ligand design.

    Science.gov (United States)

    Thépaut, Michel; Guzzi, Cinzia; Sutkeviciute, Ieva; Sattin, Sara; Ribeiro-Viana, Renato; Varga, Norbert; Chabrol, Eric; Rojo, Javier; Bernardi, Anna; Angulo, Jesus; Nieto, Pedro M; Fieschi, Franck

    2013-02-20

    In genital mucosa, different fates are described for HIV according to the subtype of dendritic cells (DCs) involved in its recognition. This notably depends on the C-type lectin receptor, langerin or DC-SIGN, involved in gp120 interaction. Langerin blocks HIV transmission by its internalization in specific organelles of Langerhans cells. On the contrary, DC-SIGN enhances HIV trans-infection of T lymphocytes. Thus, approaches aiming to inhibit DC-SIGN, without blocking langerin, represent attractive anti-HIV strategies. We previously demonstrated that dendrons bearing multiple copies of glycomimetic compounds were able to block DC-SIGN-dependent HIV infection in cervical explant models. Optimization of such ligand requires detailed characterization of its binding mode. In the present work, we determined the first high-resolution structure of a glycomimetic/DC-SIGN complex by X-ray crystallography. This glycomimetic, pseudo-1,2-mannobioside, shares shape and conformational properties with Manα1-2Man, its natural counterpart. However, it uses the binding epitope previously described for Lewis X, a ligand specific for DC-SIGN among the C-type lectin family. Thus, selectivity gain for DC-SIGN versus langerin is observed with pseudo-1,2-mannobioside as shown by surface plasmon resonance analysis. In parallel, ligand binding was also analyzed by TR-NOESY and STD NMR experiments, combined with the CORCEMA-ST protocol. These studies demonstrate that the complex, defined by X-ray crystallography, represents the unique binding mode of this ligand as opposed to the several binding orientations described for the natural ligand. This exclusive binding mode and its selective interaction properties position this glycomimetic as a good lead compound for rational improvement based on a structurally driven approach.

  11. Influence of organic waste type and soil structure on the bacterial filtration rates in unsaturated intact soil columns.

    Science.gov (United States)

    Mosaddeghi, M R; Mahboubi, A A; Zandsalimi, S; Unc, A

    2009-02-01

    better structured SCL. While the results confirmed the significant role of soil structure and preferential (macroporous) pathways, manure type was proven to have a major role in determining the maximum penetration risk of bacteria by governing filtration of bacteria. Thus while the numbers of bacteria in waste may be of significance for shallow aquifers, the type of waste may determine the risk for microbial contamination of deep aquifers.

  12. Exploring the thermal expansion of fluorides and oxyfluorides with rhenium trioxide-type structures: From negative to positive thermal expansion

    Science.gov (United States)

    Greve, Benjamin K.

    This thesis explores the thermal expansion and high pressure behavior of some materials with the ReO3 structure type. This structure is simple and has, in principle, all of the features necessary for negative thermal expansion (NTE) arising from the transverse thermal motion of the bridging anions and the coupled rotation of rigid units; however, ReO 3 itself only exhibits mild NTE across a narrow temperature range at low temperatures. ReO3 is metallic because of a delocalized d-electron, and this may contribute to the lack of NTE in this material. The materials examined in this thesis are all based on d 0 metal ions so that the observed thermal expansion behavior should arise from vibrational, rather than electronic, effects. In Chapter 2, the thermal expansion of scandium fluoride, ScF3 , is examined using a combination of in situ synchrotron X-ray and neutron variable temperature diffraction. ScF3 retains the cubic ReO3 structure across the entire temperature range examined (10 - 1600 K) and exhibits pronounced negative thermal expansion at low temperatures. The magnitude of NTE in this material is comparable to that of cubic ZrW2O8, which is perhaps the most widely studied NTE material, at room temperature and below. This is the first report of NTE in an ReO3 type structure across a wide temperature range. Chapter 3 presents a comparison between titanium oxyfluoride, TiOF 2, and a vacancy-containing titanium hydroxyoxyfluoride, Ti x(O/OH/F)3. TiOF2 was originally reported to adopt the cubic ReO3 structure type under ambient conditions, therefore the initial goal for this study was to examine the thermal expansion of this material and determine if it displayed interesting behavior such as NTE. During the course of the study, it was discovered that the original synthetic method resulted in Tix(O/OH/F)3, which does adopt the cubic ReO3 structure type. The chemical composition of the hydroxyoxyfluoride is highly dependent upon synthesis conditions and subsequent

  13. Structural basis of typhoid: Salmonella typhi type IVb pilin (PiLS) and cystic fibrosis transmembrane conductance regulator interaction

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishna, A.M.; Saxena, A.; Mok, H. Y.-K.; Swaminathan, K.

    2009-11-01

    The type IVb pilus of the enteropathogenic bacteria Salmonella typhi is a major adhesion factor during the entry of this pathogen into gastrointestinal epithelial cells. Its target of adhesion is a stretch of 10 residues from the first extracellular domain of cystic fibrosis transmembrane conductance regulator (CFTR). The crystal structure of the N-terminal 25 amino acid deleted S. typhi native PilS protein ({Delta}PilS), which makes the pilus, was determined at 1.9 {angstrom} resolution by the multiwavelength anomalous dispersion method. Also, the structure of the complex of {Delta}PilS and a target CFTR peptide, determined at 1.8 {angstrom}, confirms that residues 113-117 (NKEER) of CFTR are involved in binding with the pilin protein and gives us insight on the amino acids that are essential for binding. Furthermore, we have also explored the role of a conserved disulfide bridge in pilus formation. The subunit structure and assembly architecture are crucial for understanding pilus functions and designing suitable therapeutics against typhoid.

  14. Abundance and Structure of African Baobab (Adansonia digitata across Different Soil Types in Gonarezhou National Park, Zimbabwe

    Directory of Open Access Journals (Sweden)

    Clayton Mashapa

    2013-01-01

    Full Text Available This study investigated the abundance and structure of African baobab (Adansonia digitata across soil group strata in Gonarezhou National Park, Zimbabwe. The study was based on a stratified random sampling design composed of the following soil group substrates: (i granophyres, (ii malvernia, and (iii rhyolite. Belt transects of 0.3×0.1 km were randomly laid across soil group. Baobab abundance and population structure were determined from the density and size class distribution, respectively. There were significant differences in plant height and plant density across Gonarezhou soil groups. Study sites on granophyres derived soil group indicated viable abundance and recruitment of baobab population. Whereas the study highlighted a concern over the unbalanced size structure distribution of baobab population on malvernia derived soil group, our results indicated that baobabs are in danger of extirpation on malvernia derived soil group. Baobab community in Gonarezhou tends to occur more densely along environmental gradient of soil group type as influenced by the underlying geological soil substrate of granophyres. Malvernia derived soil group is likely less ideal for baobab recruitment.

  15. Structural and Biophysical Analysis of the Soluble DHH/DHHA1-Type Phosphodiesterase TM1595 from Thermotoga maritima.

    Science.gov (United States)

    Drexler, David Jan; Müller, Martina; Rojas-Cordova, Carlos Alberto; Bandera, Adrian Maurice; Witte, Gregor

    2017-12-05

    The concentration of messenger molecules in bacterial cells needs to be tightly regulated. This can be achieved by either controlling the synthesis rate, degradation, or export by specific transporters, respectively. The regulation of the essential second messenger c-di-AMP is achieved by modulation of the diadenylate cyclase activity as well as by specific phosphodiesterases that hydrolyze c-di-AMP in the cell. We provide here structural and biochemical data on the DHH-type phosphodiesterase TmPDE (TM1595) from Thermotoga maritima. Our analysis shows that TmPDE is preferentially degrading linear dinucleotides, such as 5'-pApA, 5'-pGpG, and 5'-pApG, compared with cyclic dinucleotide substrates. The high-resolution structural data provided here describe all steps of the PDE reaction: the ligand-free enzyme, two substrate-bound states, and three post-reaction states. We can furthermore show that Pde2 from Streptococcus pneumoniae shares both structural features and substrate specificity based on small-angle X-ray scattering data and biochemical assays. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Potential use of avocado oil on structured lipids MLM-type production catalysed by commercial immobilised lipases.

    Science.gov (United States)

    Caballero, Eduardo; Soto, Carmen; Olivares, Araceli; Altamirano, Claudia

    2014-01-01

    Structured Lipids are generally constituents of functional foods. Growing demands for SL are based on a fuller understanding of nutritional requirements, lipid metabolism, and improved methods to produce them. Specifically, this work was aimed to add value to avocado oil by producing dietary triacylglycerols (TAG) containing medium-chain fatty acids (M) at positions sn-1,3 and long-chain fatty acids (L) at position sn-2. These MLM-type structured lipids (SL) were produced by interesterification of caprylic acid (CA) (C8:0) and avocado oil (content of C18:1). The regiospecific sn-1,3 commercial lipases Lipozyme RM IM and TL IM were used as biocatalysts to probe the potential of avocado oil to produce SL. Reactions were performed at 30-50°C for 24 h in solvent-free media with a substrate molar ratio of 1∶2 (TAG:CA) and 4-10% w/w enzyme content. The lowest incorporation of CA (1.1% mol) resulted from Lipozyme RM IM that was incubated at 50°C. The maximum incorporation of CA into sn-1,3 positions of TAG was 29.2% mol. This result was obtained at 30°C with 10% w/w Lipozyme TL IM, which is the highest values obtained in solvent-free medium until now for structured lipids of low-calories. This strategy opens a new market to added value products based on avocado oil.

  17. Crystal structure and relaxor-type transition in SrBi(2)Ta(2)O(9) doped with praseodymium.

    Science.gov (United States)

    Mata, J; Durán, A; Martínez, E; Escamilla, R; Heiras, J; Siqueiros, J M

    2006-11-22

    The effects of Pr substitution in the structure and ferroelectric response for the Sr(1-x)Pr(x)Bi(2)Ta(2)O(9) (SBT-Pr) compound have been studied. Rietveld refinement of the x-ray diffraction patterns indicates that the Pr ion progressively replaces the Sr site in the A 2(1)am space group structure. The solubility of Pr in solid solution is around 15%. The replacement induces a change in the crystal structure and, as a consequence, the dielectric properties are affected. The ferroelectric transition at T(m)∼558 K is shifted to lower temperatures, T(m)∼413 K for x = 0.15 composition. Apparently, the tilt angle (α) associated with the c-axis does not play an important role since it remains essentially constant. However, the rotation in the ab-plane (β) as well as the octahedral distortion observed are strongly related to the coupling between T(m) and x. A relaxor-type transition is observed as Pr is increased, leading to polar microregions above the nominal ferroelectric transition. The local disorder induced by the Pr ion is confirmed by the continuous increase in the diffuseness coefficient according to Isupov's model. These facts hinder the displacement of the TaO(6) octahedra with respect to Bi(2)O(2) along the polarization axis, decreasing the polarization values.

  18. Comprehensive molecular mechanics model for oxidized type I copper proteins: active site structures, strain energies, and entatic bulging.

    Science.gov (United States)

    Deeth, Robert J

    2007-05-28

    The ligand field molecular mechanics (LFMM) model has been applied to the oxidized Type 1 copper center. In conjunction with the AMBER94 force field implemented in DommiMOE, the ligand field extension of the molecular operating environment (MOE), LFMM parameters for Cu-N(imidazole), Cu-S(thiolate), Cu-S(thioether), and Cu-O(carbonyl) interactions were developed on the basis of experimental and theoretical data for homoleptic model systems. Subsequent LFMM optimizations of the active site model complex [Cu(imidazole)2(SMe)(SMe2]+ agree with high level quantum results both structurally and energetically. Stable trigonal and tetragonal structures are located with the latter about 1.5 kcal mol-1 lower in energy. Fully optimized unconstrained structures were computed for 24 complete proteins containing T1 centers spanning four-coordinate, plastocyanin-like CuN2SS' and stellacyanin-like CuN2SO sites, plus the five-coordinate CuN2SS'O sites of the azurins. The initial structures were based on PDB coordinates augmented by a 10 A layer of water molecules. Agreement between theory and experiment is well within the experimental uncertainties. Moreover, the LFMM results for plastocyanin (Pc), cucumber basic protein (CBP) and azurin (Az) are at least as good as previously reported QM/MM structures and are achieved several orders of magnitude faster. The LFMM calculations suggest the protein provides an entatic strain of about 10 kcal mol-1. However, when combined with the intrinsic 'plasticity' of d9 Cu(II), different starting protein/solvent configurations can have a significant effect on the final optimized structure. This 'entatic bulging' results in relatively large fluctuations in the calculated metal-ligand bond lengths. For example, simply on the basis of 25 different starting configurations of the solvent molecules, the optimized Cu-S(thiolate) bond lengths in Pc vary by 0.04 A while the Cu-S(thioether) distance spans over 0.3 A. These variations are the same order of

  19. Crystal structure of 2-enoyl-CoA hydratase 2 from human peroxisomal multifunctional enzyme type 2.

    Science.gov (United States)

    Koski, Kristian M; Haapalainen, Antti M; Hiltunen, J Kalervo; Glumoff, Tuomo

    2005-02-04

    2-Enoyl-CoA hydratase 2 is the middle part of the mammalian peroxisomal multifunctional enzyme type 2 (MFE-2), which is known to be important in the beta-oxidation of very-long-chain and alpha-methyl-branched fatty acids as well as in the synthesis of bile acids. Here, we present the crystal structure of the hydratase 2 from the human MFE-2 to 3A resolution. The three-dimensional structure resembles the recently solved crystal structure of hydratase 2 from the yeast, Candida tropicalis, MFE-2 having a two-domain subunit structure with a C-domain complete hot-dog fold housing the active site, and an N-domain incomplete hot-dog fold housing the cavity for the aliphatic acyl part of the substrate molecule. The ability of human hydratase 2 to utilize such bulky compounds which are not physiological substrates for the fungal ortholog, e.g. CoA esters of C26 fatty acids, pristanic acid and di/trihydroxycholestanoic acids, is explained by a large hydrophobic cavity formed upon the movements of the extremely mobile loops I-III in the N-domain. In the unliganded form of human hydratase 2, however, the loop I blocks the entrance of fatty enoyl-CoAs with chain-length >C8. Therefore, we expect that upon binding of substrates bulkier than C8, the loop I gives way, contemporaneously causing a secondary effect in the CoA-binding pocket and/or active site required for efficient hydration reaction. This structural feature would explain the inactivity of human hydratase 2 towards short-chain substrates. The solved structure is also used as a tool for analyzing the various inactivating mutations, identified among others in MFE-2-deficient patients. Since hydratase 2 is the last functional unit of mammalian MFE-2 whose structure has been solved, the organization of the functional units in the biologically active full-length enzyme is also discussed.

  20. Structure-Function Basis of Attenuated Inverse Agonism of Angiotensin II Type 1 Receptor Blockers for Active-State Angiotensin II Type 1 Receptor.

    Science.gov (United States)

    Takezako, Takanobu; Unal, Hamiyet; Karnik, Sadashiva S; Node, Koichi

    2015-09-01

    Ligand-independent signaling by the angiotensin II type 1 receptor (AT1R) can be activated in clinical settings by mechanical stretch and autoantibodies as well as receptor mutations. Transition of the AT1R to the activated state is known to lower inverse agonistic efficacy of clinically used AT1R blockers (ARBs). The structure-function basis for reduced efficacy of inverse agonists is a fundamental aspect that has been understudied not only in relation to the AT1R but also regarding other homologous receptors. Here, we demonstrate that the active-state transition in the AT1R indeed attenuates an inverse agonistic effect of four biphenyl-tetrazole ARBs through changes in specific ligand-receptor interactions. In the ground state, tight interactions of four ARBs with a set of residues (Ser109(TM3), Phe182(ECL2), Gln257(TM6), Tyr292(TM7), and Asn295(TM7)) results in potent inverse agonism. In the activated state, the ARB-AT1R interactions shift to a different set of residues (Val108(TM3), Ser109(TM3), Ala163(TM4), Phe182(ECL2), Lys199(TM5), Tyr292(TM7), and Asn295(TM7)), resulting in attenuated inverse agonism. Interestingly, V108I, A163T, N295A, and F182A mutations in the activated state of the AT1R shift the functional response to the ARB binding toward agonism, but in the ground state the same mutations cause inverse agonism. Our data show that the second extracellular loop is an important regulator of the functional states of the AT1R. Our findings suggest that the quest for discovering novel ARBs, and improving current ARBs, fundamentally depends on the knowledge of the unique sets of residues that mediate inverse agonistic potency in the two states of the AT1R. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.