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Sample records for unique low-symmetry structures

  1. Unique atom hyper-kagome order in Na4Ir3O8 and in low-symmetry spinel modifications.

    Science.gov (United States)

    Talanov, V M; Shirokov, V B; Talanov, M V

    2015-05-01

    Group-theoretical and thermodynamic methods of the Landau theory of phase transitions are used to investigate the hyper-kagome atomic order in structures of ordered spinels and a spinel-like Na4Ir3O8 crystal. The formation of an atom hyper-kagome sublattice in Na4Ir3O8 is described theoretically on the basis of the archetype (hypothetical parent structure/phase) concept. The archetype structure of Na4Ir3O8 has a spinel-like structure (space group Fd\\bar 3m) and composition [Na1/2Ir3/2](16d)[Na3/2](16c)O(32e)4. The critical order parameter which induces hypothetical phase transition has been stated. It is shown that the derived structure of Na4Ir3O8 is formed as a result of the displacements of Na, Ir and O atoms, and ordering of Na, Ir and O atoms, ordering dxy, dxz, dyz orbitals as well. Ordering of all atoms takes place according to the type 1:3. Ir and Na atoms form an intriguing atom order: a network of corner-shared Ir triangles called a hyper-kagome lattice. The Ir atoms form nanoclusters which are named decagons. The existence of hyper-kagome lattices in six types of ordered spinel structures is predicted theoretically. The structure mechanisms of the formation of the predicted hyper-kagome atom order in some ordered spinel phases are established. For a number of cases typical diagrams of possible crystal phase states are built in the framework of the Landau theory of phase transitions. Thermodynamical conditions of hyper-kagome order formation are discussed by means of these diagrams. The proposed theory is in accordance with experimental data.

  2. Transformation Paths from Cubic to Low-Symmetry Structures in Heusler Ni2MnGa Compound.

    Science.gov (United States)

    Zelený, Martin; Straka, Ladislav; Sozinov, Alexei; Heczko, Oleg

    2018-05-08

    In order to explain the formation of low-temperature phases in stoichiometric Ni 2 MnGa magnetic shape memory alloy, we investigate the phase transformation paths from cubic austenite with Heusler structure to low-symmetry martensitic structures. We used ab initio calculations combined with the generalized solid state nudged elastic band method to determine the minimum energy path and corresponding changes in crystal lattice. The four-, five-, and seven-layered modulated phases of martensite (4O, 10M, and 14M) are built as the relaxed nanotwinned non-modulated (NM) phase. Despite having a total energy larger than the other martensitic phases, the 10M phase will spontaneously form at 0 K, because there is no energy barrier on the path and the energy decreases with a large negative slope. Moreover, a similar negative slope in the beginning of path is found also for the transformation to the 6M premartensite, which appears as a local minimum on the path leading further to 10M martensite. Transformation paths to other structures exhibit more or less significant barriers in the beginning hindering such a transformation from austenite. These findings correspond to experiment and demonstrates that the kinetics of the transformation is decisive for the selection of the particular low-symmetry structure.

  3. Characterization of Low-Symmetry Structures from Phase Equilibrium of Fe-Al System—Microstructures and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Piotr Matysik

    2015-03-01

    Full Text Available Fe-Al intermetallic alloys with aluminum content over 60 at% are in the area of the phase equilibrium diagram that is considerably less investigated in comparison to the high-symmetry Fe3Al and FeAl phases. Ambiguous crystallographic information and incoherent data referring to the phase equilibrium diagrams placed in a high-aluminum range have caused confusions and misinformation. Nowadays unequivocal material properties description of FeAl2, Fe2Al5 and FeAl3 intermetallic alloys is still incomplete. In this paper, the influence of aluminum content and processing parameters on phase composition is presented. The occurrence of low-symmetry FeAl2, Fe2Al5 and FeAl3 structures determined by chemical composition and phase transformations was defined by scanning electron microscopy (SEM and energy-dispersive X-ray spectroscopy (EDS examinations. These results served to verify diffraction investigations (XRD and to explain the mechanical properties of cast materials such as: hardness, Young’s modulus and fracture toughness evaluated using the nano-indentation technique.

  4. Characterization of Low-Symmetry Structures from Phase Equilibrium of Fe-Al System-Microstructures and Mechanical Properties.

    Science.gov (United States)

    Matysik, Piotr; Jóźwiak, Stanisław; Czujko, Tomasz

    2015-03-04

    Fe-Al intermetallic alloys with aluminum content over 60 at% are in the area of the phase equilibrium diagram that is considerably less investigated in comparison to the high-symmetry Fe₃Al and FeAl phases. Ambiguous crystallographic information and incoherent data referring to the phase equilibrium diagrams placed in a high-aluminum range have caused confusions and misinformation. Nowadays unequivocal material properties description of FeAl₂, Fe₂Al₅ and FeAl₃ intermetallic alloys is still incomplete. In this paper, the influence of aluminum content and processing parameters on phase composition is presented. The occurrence of low-symmetry FeAl₂, Fe₂Al₅ and FeAl₃ structures determined by chemical composition and phase transformations was defined by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) examinations. These results served to verify diffraction investigations (XRD) and to explain the mechanical properties of cast materials such as: hardness, Young's modulus and fracture toughness evaluated using the nano-indentation technique.

  5. On standardization of low symmetry crystal fields

    Science.gov (United States)

    Gajek, Zbigniew

    2015-07-01

    Standardization methods of low symmetry - orthorhombic, monoclinic and triclinic - crystal fields are formulated and discussed. Two alternative approaches are presented, the conventional one, based on the second-rank parameters and the standardization based on the fourth-rank parameters. Mainly f-electron systems are considered but some guidelines for d-electron systems and the spin Hamiltonian describing the zero-field splitting are given. The discussion focuses on premises for choosing the most suitable method, in particular on inadequacy of the conventional one. Few examples from the literature illustrate this situation.

  6. Unique structural features facilitate lizard tail autotomy.

    Science.gov (United States)

    Sanggaard, Kristian W; Danielsen, Carl Chr; Wogensen, Lise; Vinding, Mads S; Rydtoft, Louise M; Mortensen, Martin B; Karring, Henrik; Nielsen, Niels Chr; Wang, Tobias; Thøgersen, Ida B; Enghild, Jan J

    2012-01-01

    Autotomy refers to the voluntary shedding of a body part; a renowned example is tail loss among lizards as a response to attempted predation. Although many aspects of lizard tail autotomy have been studied, the detailed morphology and mechanism remains unclear. In the present study, we showed that tail shedding by the Tokay gecko (Gekko gecko) and the associated extracellular matrix (ECM) rupture were independent of proteolysis. Instead, lizard caudal autotomy relied on biological adhesion facilitated by surface microstructures. Results based on bio-imaging techniques demonstrated that the tail of Gekko gecko was pre-severed at distinct sites and that its structural integrity depended on the adhesion between these segments.

  7. Unique structural features facilitate lizard tail autotomy.

    Directory of Open Access Journals (Sweden)

    Kristian W Sanggaard

    Full Text Available Autotomy refers to the voluntary shedding of a body part; a renowned example is tail loss among lizards as a response to attempted predation. Although many aspects of lizard tail autotomy have been studied, the detailed morphology and mechanism remains unclear. In the present study, we showed that tail shedding by the Tokay gecko (Gekko gecko and the associated extracellular matrix (ECM rupture were independent of proteolysis. Instead, lizard caudal autotomy relied on biological adhesion facilitated by surface microstructures. Results based on bio-imaging techniques demonstrated that the tail of Gekko gecko was pre-severed at distinct sites and that its structural integrity depended on the adhesion between these segments.

  8. MCD spectroscopy and TD-DFT calculations of low symmetry subnaphthalocyanine analogs.

    Science.gov (United States)

    Mack, John; Otaki, Tatsuya; Durfee, William S; Kobayashi, Nagao; Stillman, Martin J

    2014-07-01

    Magnetic circular dichroism (MCD) spectroscopy and time-dependent density functional theory (TD-DFT) calculations are used to analyze the electronic structure and optical properties of low-symmetry subnaphthalocyanine analogs with AAB and ABB structures formed during mixed condensations of tetrafluorophthalonitrile and 2,3-naphthalenedicarbonitrile. The results demonstrate that trends observed in the properties of phthalocyanine analogs can be used to fine tune the optical properties so that the Q(0,0) bands lie in the red region, in a manner that does not significantly destabilize the highest occupied molecular orbital (HOMO) energy relative to that of the parent subphthalocyanine ligand. Attempts to study the spectroscopy of anion radical species proved unsuccessful, since they proved to be unstable. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Low-Symmetry Gap Functions of Organic Superconductors

    Science.gov (United States)

    Mori, Takehiko

    2018-04-01

    Superconducting gap functions of various low-symmetry organic superconductors are investigated starting from the tight-binding energy band and the random phase approximation by numerically solving Eliashberg's equation. The obtained singlet gap function is approximately represented by an asymmetrical dx2 - y2 form, where two cosine functions are mixed in an appropriate ratio. This is usually called d + s wave, where the ratio of the two cosine functions varies from 1:1 in the two-dimensional limit to 1:0 in the one-dimensional limit. A single cosine function does not make a superconducting gap in an ideal one-dimensional conductor, but works as a relevant gap function in quasi-one-dimensional conductors with slight interchain transfer integrals. Even when the Fermi surface is composed of small pockets, the gap function is obtained supposing a globally connected elliptical Fermi surface. In such a case, we have to connect the second energy band in the second Brillouin zone. The periodicity of the resulting gap function is larger than the first Brillouin zone. This is because the susceptibility has peaks at 2kF, where the periodicity has to be twice the size of the global Fermi surface. In general, periodicity of gap function corresponds to one electron or two molecules in the real space. In the κ-phase, two axes are nonequivalent, but the exact dx2 - y2 symmetry is maintained because the diagonal transfer integral introduced to a square lattice is oriented to the node direction of the dx2 - y2 wave. By contrast, the θ-phase gap function shows considerable anisotropy because a quarter-filled square lattice has a different dxy symmetry.

  10. Instability of Yb3+ and Pr3+ low-symmetry luminescence centers in gallium phosphide

    International Nuclear Information System (INIS)

    Kasatkin, V.A.

    1985-01-01

    The stability of γb 3+ and Pr 3+ low-symmetry luminescence centers formed in gallium phosphide during quenching were studied in the process of durable storage and annealing. Observation of the Yb 3+ and Pr 3+ centrer states was accomplished by the photoluminescence spectra at 18 K. It has been established that annealing in the dark under normal conditions results in a reduced integral luminescence intensity of all low-symmetry Yb 3+ and Pr 3+ centers. Annealing of quenched GaP and GaP saples at 400 K results in complete disappearance of intracenter luminescence of Pr 3+ and low-symmetry Yb 3+ centers. Decomposition during storage and low anealing temperature point to the instability of low-symmetry centers of Pr 3+ and Yb 3+ luminescence

  11. Unique Structural Features of Influenza Virus H15 Hemagglutinin

    Energy Technology Data Exchange (ETDEWEB)

    Tzarum, Netanel; McBride, Ryan; Nycholat, Corwin M.; Peng, Wenjie; Paulson, James C.; Wilson, Ian A. (Scripps)

    2017-04-12

    Influenza A H15 viruses are members of a subgroup (H7-H10-H15) of group 2 hemagglutinin (HA) subtypes that include H7N9 and H10N8 viruses that were isolated from humans during 2013. The isolation of avian H15 viruses is, however, quite rare and, until recently, geographically restricted to wild shorebirds and waterfowl in Australia. The HAs of H15 viruses contain an insertion in the 150-loop (loop beginning at position 150) of the receptor-binding site common to this subgroup and a unique insertion in the 260-loop compared to any other subtype. Here, we show that the H15 HA has a high preference for avian receptor analogs by glycan array analyses. The H15 HA crystal structure reveals that it is structurally closest to H7N9 HA, but the head domain of the H15 trimer is wider than all other HAs due to a tilt and opening of the HA1 subunits of the head domain. The extended 150-loop of the H15 HA retains the conserved conformation as in H7 and H10 HAs. Furthermore, the elongated 260-loop increases the exposed HA surface and can contribute to antigenic variation in H15 HAs. Since avian-origin H15 HA viruses have been shown to cause enhanced disease in mammalian models, further characterization and immune surveillance of H15 viruses are warranted.

    IMPORTANCEIn the last 2 decades, an apparent increase has been reported for cases of human infection by emerging avian influenza A virus subtypes, including H7N9 and H10N8 viruses isolated during 2013. H15 is the other member of the subgroup of influenza A virus group 2 hemagglutinins (HAs) that also include H7 and H10. H15 viruses have been restricted to Australia, but recent isolation of H15 viruses in western Siberia suggests that they could be spread more globally via the avian flyways that converge and emanate from this region. Here we report on characterization of the three-dimensional structure and receptor specificity of the H15 hemagglutinin, revealing distinct features and specificities that can

  12. Understanding `galaxy groups' as a unique structure in the universe

    Science.gov (United States)

    Paul, S.; John, R. S.; Gupta, P.; Kumar, H.

    2017-10-01

    'Galaxy groups' have hardly been realized as a separate class of objects with specific characteristics in the structural hierarchy. The presumption that the self-similarity of dark matter structures is a valid prescription for the baryonic universe at all scales has rendered smaller structures undetectable by current observational facilities, leading to lesser dedicated studies on them. Some recent reports that indicate a deviation from LX-T scaling in groups compared to clusters have motivated us to study their physical properties in depth. In this article, we report the extensive study on physical properties of groups in comparison to the clusters through cosmological hydrodynamic plus N-body simulations using enzo 2.2 code. As additional physics, radiative cooling, heating due to supernova and star motions, star formation and stellar feedback have been implemented. We have produced a mock sample of 362 objects with mass ranging from 5 × 1012 M⊙ to 2.5 × 1015 M⊙. Strikingly, we have found that objects with mass below ˜8 × 1013 M⊙ do not follow any of the cluster self-similar laws in hydrostatics, not even in thermal and non-thermal energies. Two distinct scaling laws are observed to be followed with breaks at ˜8 × 1013 M⊙ for mass, ˜1 keV for temperature and ˜1 Mpc for radius. This places groups as a distinct entity in the hierarchical structures, well demarcated from clusters. This study reveals that groups are mostly far away from virialization, suggesting the need for formulating new models for deciphering their physical parameters. They are also shown to have high turbulence and more non-thermal energy stored, indicating better visibility in the non-thermal regime.

  13. Understanding 'Galaxy Groups' as a Unique Structure in the Universe

    Science.gov (United States)

    John, Reju Sam; Paul, Surajit; Gupta, Prateek; Kumar, Harish

    2017-07-01

    'Galaxy groups' have hardly been realized as a separate class of objects with specific characteristics in the structural hierarchy of the universe. The presumption that the self-similarity of dark matter structures is a valid prescription for the baryonic universe also at all scales has rendered smaller structures undetectable by current observational facilities, leading to lesser dedicated studies on them. Some recent reports on deviation of {L_x}-T scaling in groups from that of clusters have motivated us to study their physical properties in depth. In this article, we report the extensive study on physical properties of groups in comparison with clusters through cosmological hydrodynamic plus N-body simulations using ENZO 2.2 code. We have included cooling and heating physics and star formation feedback in the simulation. And produced a mock sample of 362 objects with mass ranging from 5×10^{12} M_{⊙} to 2.5×10^{15} M_{⊙}. Strikingly, we have found that objects with a mass below ˜ 8×10^{13} M_{⊙} do not follow any of the cluster self-similar laws in hydrostatics, not even in thermal and non-thermal regimes. Two distinct scaling laws are observed to be followed with breaks at ˜ 6-8× 10^{13} M_{⊙} for mass, ˜1 keV for temperature and ˜1 Mpc for radius. This places groups as a distinct entity in the hierarchical structures, well demarcated from clusters. This study reveals that groups are mostly far away from virialization, suggesting the need for formulating new models for deciphering their physical parameters. They are also shown to have high turbulence and more non-thermal energy stored, indicating better visibility in the non-thermal regime.

  14. Electrospun superhydrophobic membranes with unique structures for membrane distillation.

    Science.gov (United States)

    Liao, Yuan; Loh, Chun-Heng; Wang, Rong; Fane, Anthony G

    2014-09-24

    With modest temperature demand, low operating pressure, and high solute rejection, membrane distillation (MD) is an attractive option for desalination, waste treatment, and food and pharmaceutical processing. However, large-scale practical applications of MD are still hindered by the absence of effective membranes with high hydrophobicity, high porosity, and adequate mechanical strength, which are important properties for MD permeation fluxes, stable long-term performance, and effective packing in modules without damage. This study describes novel design strategies for highly robust superhydrophobic dual-layer membranes for MD via electrospinning. One of the newly developed membranes comprises a durable and ultrathin 3-dimensional (3D) superhydrophobic skin and porous nanofibrous support whereas another was fabricated by electrospinning 3D superhydrophobic layers on a nonwoven support. These membranes exhibit superhydrophobicity toward distilled water, salty water, oil-in-water emulsion, and beverages, which enables them to be used not only for desalination but also for other processes. The superhydrophobic dual-layer membrane #3S-N with nanofibrous support has a competitive permeation flux of 24.6 ± 1.2 kg m(-2) h(-1) in MD (feed and permeate temperate were set as 333 and 293 K, respectively) due to the higher porosity of the nanofibrous scaffold. Meanwhile, the membranes with the nonwoven support exhibit greater mechanical strength due to this support combined with better long-term performance because of the thicker 3D superhydrophobic layers. The morphology, pore size, porosity, mechanical properties, and liquid enter pressure of water of these superhydrophobic composite membranes with two different structures are reported and compared with commercial polyvinylidene fluoride membranes.

  15. Structure determination of human Lck unique and SH3 domains by nuclear magnetic resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Willbold Dieter

    2003-05-01

    Full Text Available Abstract Background Protein tyrosine kinases are involved in signal transduction pathways that regulate cell growth, differentiation, activation and transformation. Human lymphocyte specific kinase (Lck is a 56 kDa protein involved in T-cell- and IL2-receptor signaling. Three-dimensional structures are known for SH3, SH2 and kinase domains of Lck as well as for other tyrosine kinases. No structure is known for the unique domain of any Src-type tyrosine kinase. Results Lck(1–120 comprising unique and SH3 domains was structurally investigated by nuclear magnetic resonance spectroscopy. We found the unique domain, in contrast to the SH3 part, to have basically no defined structural elements. The solution structure of the SH3 part could be determined with very high precision. It does not show significant differences to Lck SH3 in the absence of the unique domain. Minor differences were observed to the X-ray structure of Lck SH3. Conclusion The unique domain of Lck does not contain any defined structure elements in the absence of ligands and membranes. Presence of the unique domain is not relevant to the three-dimensional structure of the Lck SH3 domain.

  16. Uniqueness of the joint measurement and the structure of the set of compatible quantum measurements

    Science.gov (United States)

    Guerini, Leonardo; Terra Cunha, Marcelo

    2018-04-01

    We address the problem of characterising the compatible tuples of measurements that admit a unique joint measurement. We derive a uniqueness criterion based on the method of perturbations and apply it to show that extremal points of the set of compatible tuples admit a unique joint measurement, while all tuples that admit a unique joint measurement lie in the boundary of such a set. We also provide counter-examples showing that none of these properties are both necessary and sufficient, thus completely describing the relation between the joint measurement uniqueness and the structure of the compatible set. As a by-product of our investigations, we completely characterise the extremal and boundary points of the set of general tuples of measurements and of the subset of compatible tuples.

  17. High-field Transport in Low Symmetry β-Ga2O3 Crystal

    Science.gov (United States)

    Ghosh, Krishnendu; Singisetti, Uttam

    High-field carrier transport plays an important role in many disciplines of electronics. Conventional transport theories work well on high-symmetry materials but lacks insight as the crystal symmetry goes down. Newly emerging materials, many of which possess low symmetry, demand more rigorous treatment of charge transport. We will present a comprehensive study of high-field transport using ab initio electron-phonon interaction (EPI) elements in a full-band Monte Carlo (FBMC) algorithm. We use monoclinic β-Ga2O3 as a benchmark low-symmetry material which is also an emerging wide-bandgap semiconductor. β-Ga2O3 has a C2m space group and a 10 atom primitive cell. In this work the EPIs are calculated under density-functional perturbation theory framework. We will focus on the computational challenges arising from many phonon modes and low crystal symmetry. Significant insights will be presented on the details of energy relaxation by the hot electrons mediated by different phonon modes. We will also show the velocity-field curves of electrons in different crystal directions. The authors acknowledge the support from the National Science Foundation Grant (ECCS 1607833). The authors also acknowledge the computing support provided by the Center for Computational Research at the University at Buffalo.

  18. Emergent Low-Symmetry Phases and Large Property Enhancements in Ferroelectric KNbO 3 Bulk Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Lummen, Tom T. A. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 USA; Leung, J. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 USA; Kumar, Amit [School of Mathematics and Physics, Queen' s University Belfast, University Road, Belfast BT71NN Northern Ireland UK; Wu, X. [Department of Physics, University of Texas at Austin, Austin TX 78712 USA; Ren, Y. [Department of Physics, University of Texas at Austin, Austin TX 78712 USA; VanLeeuwen, Brian K. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 USA; Haislmaier, Ryan C. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 USA; Holt, Martin [Center for Nanoscale Materials, Argonne National Laboratory, Argonne IL 60439 USA; Lai, Keji [Department of Physics, University of Texas at Austin, Austin TX 78712 USA; Kalinin, Sergei V. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Gopalan, Venkatraman [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 USA

    2017-06-19

    The design of new or enhanced functionality in materials is traditionally viewed as requiring the discovery of new chemical compositions through synthesis. Large property enhancements may however also be hidden within already well-known materials, when their structural symmetry is deviated from equilibrium through a small local strain or field. Here, the discovery of enhanced material properties associated with a new metastable phase of monoclinic symmetry within bulk KNbO3 is reported. This phase is found to coexist with the nominal orthorhombic phase at room temperature, and is both induced by and stabilized with local strains generated by a network of ferroelectric domain walls. While the local microstructural shear strain involved is only approximate to 0.017%, the concurrent symmetry reduction results in an optical second harmonic generation response that is over 550% higher at room temperature. Moreover, the meandering walls of the low-symmetry domains also exhibit enhanced electrical conductivity on the order of 1 S m(-1). This discovery reveals a potential new route to local engineering of significant property enhancements and conductivity through symmetry lowering in ferroelectric crystals.

  19. Exploiting Unique Structural and Functional Properties of Malarial Glycolytic Enzymes for Antimalarial Drug Development

    Directory of Open Access Journals (Sweden)

    Asrar Alam

    2014-01-01

    Full Text Available Metabolic enzymes have been known to carry out a variety of functions besides their normal housekeeping roles known as “moonlighting functions.” These functionalities arise from structural changes induced by posttranslational modifications and/or binding of interacting proteins. Glycolysis is the sole source of energy generation for malaria parasite Plasmodium falciparum, hence a potential pathway for therapeutic intervention. Crystal structures of several P. falciparum glycolytic enzymes have been solved, revealing that they exhibit unique structural differences from the respective host enzymes, which could be exploited for their selective targeting. In addition, these enzymes carry out many parasite-specific functions, which could be of potential interest to control parasite development and transmission. This review focuses on the moonlighting functions of P. falciparum glycolytic enzymes and unique structural differences and functional features of the parasite enzymes, which could be exploited for therapeutic and transmission blocking interventions against malaria.

  20. Spider Silk Violin Strings with a Unique Packing Structure Generate a Soft and Profound Timbre

    Science.gov (United States)

    Osaki, Shigeyoshi

    2012-04-01

    We overcome the difficulties in pulling long draglines from spiders, twist bundles of dragline filaments, and succeed in preparing violin strings. The twisting is found to change the cross section shapes of filaments from circular to polygonal and to optimize the packing structure with no openings among filaments providing mechanically strong and elastic strings. The spider string signal peaks of overtones for the violin are relatively large at high frequencies, generating a soft and profound timbre. Such a preferable timbre is considered to be due to the unique polygonal packing structure which provides valuable knowledge for developing new types of materials.

  1. Uranium(VI) coordination polymers with pyromellitate ligand: Unique 1D channel structures and diverse fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yingjie, E-mail: yzx@ansto.gov.au [Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Bhadbhade, Mohan [Mark Wainwright Analytical Centre, University of New South Wales, Kensington, NSW 2052 (Australia); Karatchevtseva, Inna [Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Price, Jason R. [Australian Synchrotron, 800 Blackburn Road, Clayton, VIC 3168 (Australia); Liu, Hao [Centre for Clean Energy Technology, School of Chemistry and Forensic Science, University of Technology Sydney, PO Box 123, Broadway, Sydney, NSW 2007 (Australia); Zhang, Zhaoming; Kong, Linggen [Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Čejka, Jiří [Department of Mineralogy, National Museum, Václavské náměstí, 68, Prague 1, 115 79-CZ (Czech Republic); Lu, Kim; Lumpkin, Gregory R. [Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia)

    2015-03-15

    Three new coordination polymers of uranium(VI) with pyromellitic acid (H{sub 4}btca) have been synthesized and structurally characterized. (ED)[(UO{sub 2})(btca)]·(DMSO)·3H{sub 2}O (1) (ED=ethylenediammonium; DMSO=dimethylsulfoxide) has a lamellar structure with intercalation of ED and DMSO. (NH{sub 4}){sub 2}[(UO{sub 2}){sub 6}O{sub 2}(OH){sub 6}(btca)]·~6H{sub 2}O (2) has a 3D framework built from 7-fold coordinated uranyl trinuclear units and btca ligands with 1D diamond-shaped channels (~8.5 Å×~8.6 Å). [(UO{sub 2}){sub 2}(H{sub 2}O)(btca)]·4H{sub 2}O (3) has a 3D network constructed by two types of 7-fold coordinated uranium polyhedron. The unique μ{sub 5}-coordination mode of btca in 3 enables the formation of 1D olive-shaped large channels (~4.5 Å×~19 Å). Vibrational modes, thermal stabilities and fluorescence properties have been investigated. - Graphical abstract: Table of content: three new uranium(VI) coordination polymers with pyromellitic acid (H{sub 4}btca) have been synthesized via room temperature and hydrothermal synthesis methods, and structurally characterized. Two to three dimensional (3D) frameworks are revealed. All 3D frameworks have unique 1D large channels. Their vibrational modes, thermal stabilities and photoluminescence properties have been investigated. - Highlights: • Three new coordination polymers of U(VI) with pyromellitic acid (H{sub 4}btca). • Structures from a 2D layer to 3D frameworks with unique 1D channels. • Unusual µ{sub 5}-(η{sub 1}:η{sub 2}:η{sub 1}:η{sub 2:}η{sub 1}) coordination mode of btca ligand. • Vibrational modes, thermal stabilities and luminescent properties reported.

  2. Scientific Support of Construction of Unique Buildings and Structures and Facilities of Increased Danger

    Science.gov (United States)

    Alekhin, V. N.; Antipin, A. A.; Gorodilov, S. N.

    2017-11-01

    A range of works on scientific support for the construction of unique buildings and the structures and facilities of increased danger, such as airport facilities, long-span and high-rise buildings is being implemented at the department “Computer Aided Design in Civil Engineering” of Ural Federal University. The scope of work includes: numerical simulation of wind and snow loads, analysis of progressive collapse and seismic impacts, verification of design solutions. The results of wind, snow loads and progressive collapse of airport buildings in the cities of Orenburg, Rostov-on-Don and Perm are considered in the article.

  3. Unique structure and optics of the lesser eyes of the box jellyfish Tripedalia cystophora

    DEFF Research Database (Denmark)

    Garm, A; Andersson, F; Nilsson, Dan-E

    2008-01-01

    mere light meters. The slit eyes, comprising four cell types, are complex and highly asymmetric. They also hold a lens-like structure, but its optical power is minute. Optical modeling suggests spatial resolution, but only in one plane. These unique and intriguing traits support strong peripheral......The visual system of box jellyfish comprises a total of 24 eyes. These are of four types and each probably has a special function. To investigate this hypothesis the morphology and optics of the lesser eyes, the pit and slit eyes, were examined. The pit eyes hold one cell type only and are probably...

  4. Co-residence patterns in hunter-gatherer societies show unique human social structure.

    Science.gov (United States)

    Hill, Kim R; Walker, Robert S; Bozicević, Miran; Eder, James; Headland, Thomas; Hewlett, Barry; Hurtado, A Magdalena; Marlowe, Frank; Wiessner, Polly; Wood, Brian

    2011-03-11

    Contemporary humans exhibit spectacular biological success derived from cumulative culture and cooperation. The origins of these traits may be related to our ancestral group structure. Because humans lived as foragers for 95% of our species' history, we analyzed co-residence patterns among 32 present-day foraging societies (total n = 5067 individuals, mean experienced band size = 28.2 adults). We found that hunter-gatherers display a unique social structure where (i) either sex may disperse or remain in their natal group, (ii) adult brothers and sisters often co-reside, and (iii) most individuals in residential groups are genetically unrelated. These patterns produce large interaction networks of unrelated adults and suggest that inclusive fitness cannot explain extensive cooperation in hunter-gatherer bands. However, large social networks may help to explain why humans evolved capacities for social learning that resulted in cumulative culture.

  5. Unique structural modulation of a non-native substrate by cochaperone DnaJ.

    Science.gov (United States)

    Tiwari, Satyam; Kumar, Vignesh; Jayaraj, Gopal Gunanathan; Maiti, Souvik; Mapa, Koyeli

    2013-02-12

    The role of bacterial DnaJ protein as a cochaperone of DnaK is strongly appreciated. Although DnaJ unaccompanied by DnaK can bind unfolded as well as native substrate proteins, its role as an individual chaperone remains elusive. In this study, we demonstrate that DnaJ binds a model non-native substrate with a low nanomolar dissociation constant and, more importantly, modulates the structure of its non-native state. The structural modulation achieved by DnaJ is different compared to that achieved by the DnaK-DnaJ complex. The nature of structural modulation exerted by DnaJ is suggestive of a unique unfolding activity on the non-native substrate by the chaperone. Furthermore, we demonstrate that the zinc binding motif along with the C-terminal substrate binding domain of DnaJ is necessary and sufficient for binding and the subsequent binding-induced structural alterations of the non-native substrate. We hypothesize that this hitherto unknown structural alteration of non-native states by DnaJ might be important for its chaperoning activity by removing kinetic traps of the folding intermediates.

  6. The unique N-terminal zinc finger of synaptotagmin-like protein 4 reveals FYVE structure.

    Science.gov (United States)

    Miyamoto, Kazuhide; Nakatani, Arisa; Saito, Kazuki

    2017-12-01

    Synaptotagmin-like protein 4 (Slp4), expressed in human platelets, is associated with dense granule release. Slp4 is comprised of the N-terminal zinc finger, Slp homology domain, and C2 domains. We synthesized a compact construct (the Slp4N peptide) corresponding to the Slp4 N-terminal zinc finger. Herein, we have determined the solution structure of the Slp4N peptide by nuclear magnetic resonance (NMR). Furthermore, experimental, chemical modification of Cys residues revealed that the Slp4N peptide binds two zinc atoms to mediate proper folding. NMR data showed that eight Cys residues coordinate zinc atoms in a cross-brace fashion. The Simple Modular Architecture Research Tool database predicted the structure of Slp4N as a RING finger. However, the actual structure of the Slp4N peptide adopts a unique C 4 C 4 -type FYVE fold and is distinct from a RING fold. To create an artificial RING finger (ARF) with specific ubiquitin-conjugating enzyme (E2)-binding capability, cross-brace structures with eight zinc-ligating residues are needed as the scaffold. The cross-brace structure of the Slp4N peptide could be utilized as the scaffold for the design of ARFs. © 2017 The Protein Society.

  7. Magnetic anisotropy of dysprosium(III) in a low-symmetry environment: a theoretical and experimental investigation.

    Science.gov (United States)

    Bernot, Kevin; Luzon, Javier; Bogani, Lapo; Etienne, Mael; Sangregorio, Claudio; Shanmugam, Muralidharan; Caneschi, Andrea; Sessoli, Roberta; Gatteschi, Dante

    2009-04-22

    A mixed theoretical and experimental approach was used to determine the local magnetic anisotropy of the dysprosium(III) ion in a low-symmetry environment. The susceptibility tensor of the monomeric species having the formula [Dy(hfac)(3)(NIT-C(6)H(4)-OEt)(2)], which contains nitronyl nitroxide (NIT-R) radicals, was determined at various temperatures through angle-resolved magnetometry. These results are in agreement with ab initio calculations performed using the complete active space self-consistent field (CASSCF) method, validating the predictive power of this theoretical approach for complex systems containing rare-earth ions, even in low-symmetry environments. Susceptibility measurements performed with the applied field along the easy axis eventually permitted a detailed analysis of the temperature and field dependence of the magnetization, providing evidence that the Dy ion transmits an antiferromagnetic interaction between radicals but that the Dy-radical interaction is ferromagnetic.

  8. Probing the Unique Role of Gallium in Amorphous Oxide Semiconductors through Structure-Property Relationships

    Energy Technology Data Exchange (ETDEWEB)

    Moffitt, Stephanie L.; Zhu, Qimin; Ma, Qing; Falduto, Allison F.; Buchholz, D. Bruce; Chang, Robert P.H.; Mason, Thomas O.; Medvedeva, Julia E.; Marks, Tobin J.; Bedzyk, Michael J. (NWU); (MUST)

    2017-09-01

    This study explores the unique role of Ga in amorphous (a-) In[BOND]Ga[BOND]O oxide semiconductors through combined theory and experiment. It reveals substitutional effects that have not previously been attributed to Ga, and that are investigated by examining how Ga influences structure–property relationships in a series of pulsed laser deposited a-In[BOND]Ga[BOND]O thin films. Element-specific structural studies (X-ray absorption and anomalous scattering) show good agreement with the results of ab initio molecular dynamics simulations. This structural knowledge is used to understand the results of air-annealing and Hall effect electrical measurements. The crystallization temperature of a-IO is shown to increase by as much as 325 °C on substituting Ga for In. This increased thermal stability is understood on the basis of the large changes in local structure that Ga undergoes, as compared to In, during crystallization. Hall measurements reveal an initial sharp drop in both carrier concentration and mobility with increasing Ga incorporation, which moderates at >20 at% Ga content. This decline in both the carrier concentration and mobility with increasing Ga is attributed to dilution of the charge-carrying In[BOND]O matrix and to increased structural disorder. The latter effect saturates at high at% Ga.

  9. Unique Intramolecular Electronic Communications in Mono-ferrocenylpyrimidine Derivatives: Correlation between Redox Properties and Structural Nature

    International Nuclear Information System (INIS)

    Xiang, Debo; Noel, Jerome; Shao, Huibo; Dupas, Georges; Merbouh, Nabyl; Yu, Hua-Zhong

    2015-01-01

    Highlights: • Unique intramolecular electronic communications (electron withdrawing and π-bond delocalization effects) exist in the mono-ferrocenylpyrimidine derivatives. • The redox potential shift correlates the pyrimidine ring torsion angle with the extent of electron delocalization. • The correlation between redox properties and structural nature in mono-ferrocenylpyrimidine derivatives is evident. - Abstract: The correlation between redox properties and structural nature in a complete set of mono-ferrocenylpyrimidine derivatives (2-ferrocenylpyrimidine, 2-FcPy; 4-ferrocenylpyrimidine, 4-FcPy; 5-ferrocenylpyrimidine, 5-FcPy) was evaluated by investigating the intramolecular electronic communications. Both conventional electrochemical measurements in organic solvents and thin-film voltammetric studies of these compounds were carried out. It was discovered that their formal potentials are significantly different from each other, and shift negatively in the order of 4-FcPy > 5-FcPy > 2-FcPy. This result suggests that the intramolecular electronic communication is dictated by the delocalization effect of the π-bonding systems in 2-FcPy, and that the electron-withdrawing effect of the nitrogen atoms in the pyrimidine ring plays the key role in 4-FcPy and 5-FcPy. The single crystal X-ray structure analyis and Density Functional Theory (DFT) calculation provided additional evidence (e.g., different torsion angles between the cyclopentadienyl and pyrimidine rings) to support the observed correlation between the redox properties and structural nature

  10. Nuclear resonance scattering of synchrotron radiation as a unique electronic, structural and thermodynamic probe

    International Nuclear Information System (INIS)

    Alp, E. Ercan; Sturhahn, Wolfgang; Toellner, Thomas S.; Zhao, Jiyong; Leu, Bogdan M.

    2012-01-01

    (SMS). However, to place these two techniques into some perspective with respect to other methods that yield related information, they display their version of a frequently used map of momentum and energy transfer diagram in figure 17.1. Here, various probes like electrons, neutrons, or light, i.e., Brillouin or Raman, and relatively newer forms of X-ray scattering are placed according to their range of energy and momentum transfer taking place during the measurements. Accordingly, NRIXS is a method that needs to be considered as a complementary probe to inelastic neutron and X-ray scattering, while SMS occupies a unique space due to its sensitivity to magnetism, structural deformations, valence, and spin states.

  11. Unique hyper-thermal composting process in Kagoshima City forms distinct bacterial community structures.

    Science.gov (United States)

    Tashiro, Yukihiro; Tabata, Hanae; Itahara, Asuka; Shimizu, Natsuki; Tashiro, Kosuke; Sakai, Kenji

    2016-11-01

    A unique compost, Satsuma soil, is produced from three types of wastewater sludge using hyper-thermal processes at temperatures much higher than that of general thermophilic processes in Kagoshima City, Japan. We analyzed the bacterial community structures of this hyper-thermal compost sample and other sludges and composts by a high-throughput barcoded pyrosequencing method targeting the 16S rRNA gene. In total, 621,076 reads were derived from 17 samples and filtered. Artificial sequences were deleted and the reads were clustered based on the operational taxonomic units (OTUs) at 97% similarity. Phylum-level analysis of the hyper-thermal compost revealed drastic changes of the sludge structures (each relative abundance) from Firmicutes (average 47.8%), Proteobacteria (average 22.3%), and Bacteroidetes (average 10.1%) to two main phyla including Firmicutes (73.6%) and Actinobacteria (25.0%) with less Proteobacteria (∼0.3%) and Bacteroidetes (∼0.1%). Furthermore, we determined the predominant species (each relative abundance) of the hyper-thermal compost including Firmicutes related to Staphylococcus cohnii (13.8%), Jeotgalicoccus coquinae (8.01%), and Staphylococcus lentus (5.96%), and Actinobacteria related to Corynebacterium stationis (6.41%), and found that these species were not predominant in wastewater sludge. In contrast, we did not observe any common structures among eight other composts produced, using the hyper-thermal composts as the inoculums, under thermophilic conditions from different materials. Principle coordinate analysis of the hyper-thermal compost indicated a large difference in bacterial community structures from material sludge and other composts. These results suggested that a distinct bacterial community structure was formed by hyper-thermal composting. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  12. Genetic structure of a unique admixed population: implications for medical research.

    Science.gov (United States)

    Patterson, Nick; Petersen, Desiree C; van der Ross, Richard E; Sudoyo, Herawati; Glashoff, Richard H; Marzuki, Sangkot; Reich, David; Hayes, Vanessa M

    2010-02-01

    STATEMENT: In naming population groups, we think a chief aim is to use terms that the group members use themselves, or find familiar and comfortable. The terms used in this manuscript to describe populations are as historically correct as possible and are chosen so as not to offend any population group. Two of the authors (DCP and REvdR) belong to the Coloured population, with one of the authors (REvdR) having contributed extensively to current literature on the history of the Coloured people of South Africa and served as Vice-President of the South African Institute of Race Relations. According to the 2001 South African census (http://www.statssa.gov.za/census01/HTML/CInBrief/CIB2001.pdf), "Statistics South Africa continues to classify people by population group, in order to monitor progress in moving away from the apartheid-based discrimination of the past. However, membership of a population group is now based on self-perception and self-classification, not on a legal definition. Five options were provided on the questionnaire, Black African, Coloured, Indian or Asian, White and Other. Responses in the category 'Other' were very few and were therefore imputed". We have elected to use the term Bushmen rather than San to refer to the hunter-gatherer people of Southern Africa. Although they have no collective name for themselves, this decision was based on the term Bushmen (or Bossiesman) being the more familiar to the communities themselves, while the term San is the more accepted academic classification. Understanding human genetic structure has fundamental implications for understanding the evolution and impact of human diseases. In this study, we describe the complex genetic substructure of a unique and recently admixed population arising approximately 350 years ago as a direct result of European settlement in South Africa. Analysis was performed using over 900 000 genome-wide single nucleotide polymorphisms in 20 unrelated ancestry-informative marker selected

  13. The structure of Haemophilus influenzae prephenate dehydrogenase suggests unique features of bifunctional TyrA enzymes

    International Nuclear Information System (INIS)

    Chiu, Hsiu-Ju; Abdubek, Polat; Astakhova, Tamara; Axelrod, Herbert L.; Carlton, Dennis; Clayton, Thomas; Das, Debanu; Deller, Marc C.; Duan, Lian; Feuerhelm, Julie; Grant, Joanna C.; Grzechnik, Anna; Han, Gye Won; Jaroszewski, Lukasz; Jin, Kevin K.; Klock, Heath E.; Knuth, Mark W.; Kozbial, Piotr; Krishna, S. Sri; Kumar, Abhinav; Marciano, David; McMullan, Daniel; Miller, Mitchell D.; Morse, Andrew T.; Nigoghossian, Edward; Okach, Linda; Reyes, Ron; Tien, Henry J.; Trame, Christine B.; Bedem, Henry van den; Weekes, Dana; Xu, Qingping; Hodgson, Keith O.; Wooley, John; Elsliger, Marc-André; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A.

    2010-01-01

    The crystal structure of the prephenate dehydrogenase component of the bifunctional H. influenzae TyrA reveals unique structural differences between bifunctional and monofunctional TyrA enzymes. Chorismate mutase/prephenate dehydrogenase from Haemophilus influenzae Rd KW20 is a bifunctional enzyme that catalyzes the rearrangement of chorismate to prephenate and the NAD(P) + -dependent oxidative decarboxylation of prephenate to 4-hydroxyphenylpyruvate in tyrosine biosynthesis. The crystal structure of the prephenate dehydrogenase component (HinfPDH) of the TyrA protein from H. influenzae Rd KW20 in complex with the inhibitor tyrosine and cofactor NAD + has been determined to 2.0 Å resolution. HinfPDH is a dimeric enzyme, with each monomer consisting of an N-terminal α/β dinucleotide-binding domain and a C-terminal α-helical dimerization domain. The structure reveals key active-site residues at the domain interface, including His200, Arg297 and Ser179 that are involved in catalysis and/or ligand binding and are highly conserved in TyrA proteins from all three kingdoms of life. Tyrosine is bound directly at the catalytic site, suggesting that it is a competitive inhibitor of HinfPDH. Comparisons with its structural homologues reveal important differences around the active site, including the absence of an α–β motif in HinfPDH that is present in other TyrA proteins, such as Synechocystis sp. arogenate dehydrogenase. Residues from this motif are involved in discrimination between NADP + and NAD + . The loop between β5 and β6 in the N-terminal domain is much shorter in HinfPDH and an extra helix is present at the C-terminus. Furthermore, HinfPDH adopts a more closed conformation compared with TyrA proteins that do not have tyrosine bound. This conformational change brings the substrate, cofactor and active-site residues into close proximity for catalysis. An ionic network consisting of Arg297 (a key residue for tyrosine binding), a water molecule, Asp206 (from

  14. Unique spin-polarized transmission effects in a QD ring structure

    Science.gov (United States)

    Hedin, Eric; Joe, Yong

    2010-10-01

    Spintronics is an emerging field in which the spin of the electron is used for switching purposes and to communicate information. In order to obtain spin-polarized electron transmission, the Zeeman effect is employed to produce spin-split energy states in quantum dots which are embedded in the arms of a mesoscopic Aharonov-Bohm (AB) ring heterostructure. The Zeeman splitting of the QD energy levels can be induced by a parallel magnetic field, or by a perpendicular field which also produces AB-effects. The combination of these effects on the transmission resonances of the structure is studied analytically and several parameter regimes are identified which produce a high degree of spin-polarized output. Contour and line plots of the weighted spin polarization as a function of electron energy and magnetic field are presented to visualize the degree of spin-polarization. Taking advantage of these unique parameter regimes shows the potential promise of such devices for producing spin-polarized currents.

  15. The unique structural parameters of the underlying host galaxies in blue compact dwarfs

    International Nuclear Information System (INIS)

    Janowiecki, Steven; Salzer, John J.

    2014-01-01

    The nature of possible evolutionary pathways between various types of dwarf galaxies is still not fully understood. Blue compact dwarf galaxies (BCDs) provide a unique window into dwarf galaxy formation and evolution and are often thought of as an evolutionary stage between different classes of dwarf galaxies. In this study we use deep optical and near-infrared observations of the underlying hosts of BCDs in order to study the structural differences between different types of dwarf galaxies. When compared with dwarf irregular galaxies of similar luminosities, we find that the underlying hosts of BCDs have significantly more concentrated light distributions, with smaller scale lengths and brighter central surface brightnesses. We demonstrate here that the underlying hosts of BCDs are distinct from the broad continuum of typical dwarf irregular galaxies, and that it is unlikely that most dwarf irregular galaxies can transform into a BCD or vice versa. Furthermore, we find that the starburst in a BCD only brightens it on average by ∼0.8 mag (factor of two), in agreement with other studies. It appears that a BCD is a long-lived and distinct type of dwarf galaxy that exhibits an exceptionally concentrated matter distribution. We suggest that it is this compact mass distribution that enables the strong star formation events that characterize this class of dwarf galaxy, that the compactness of the underlying host can be used as a distinguishing parameter between BCDs and other dwarf galaxies, and that it can also be used to identify BCDs which are not currently experiencing an intense starburst event.

  16. Relationship between symmetry of porphyrinic pi-conjugated systems and singlet oxygen (1Delta g) yields: low-symmetry tetraazaporphyrin derivatives.

    Science.gov (United States)

    Ishii, Kazuyuki; Itoya, Hatsumi; Miwa, Hideya; Fujitsuka, Mamoru; Ito, Osamu; Kobayashi, Nagao

    2005-07-07

    We have investigated the excited-state properties and singlet oxygen ((1)Delta(g)) generation mechanism in phthalocyanines (4M; M = H(2), Mg, or Zn) and in low-symmetry metal-free, magnesium, and zinc tetraazaporphyrins (TAPs), that is, monobenzo-substituted (1M), adjacently dibenzo-substituted (2AdM), oppositely dibenzo-substituted (2OpM), and tribenzo-substituted (3M) TAP derivatives, whose pi conjugated systems were altered by fusing benzo rings. The S(1)(x) and S(1)(y) states (these lowest excited singlet states are degenerate in D(4)(h) symmetry) split in the low-symmetry TAP derivatives. The excited-state energies were quantitatively determined from the electronic absorption spectra. The lowest excited triplet (T(1)(x)) energies were also determined from phosphorescence spectra, while the second lowest excited triplet (T(1)(y)) states were evaluated by using the energy splitting between the T(1)(x) and T(1)(y) states previously reported (Miwa, H.; Ishii, K.; Kobayashi, N. Chem. Eur. J. 2004, 10, 4422-4435). The singlet oxygen quantum yields (Phi(Delta)) are strongly dependent on the pi conjugated system. In particular, while the Phi(Delta) value of 2AdH(2) is smallest in our system, that of 2OpH(2), an isomer of 2AdH(2), is larger than that of 4Zn, in contrast to the heavy atom effect. The relationship between the molecular structure and Phi(Delta) values can be transformed into a relationship between the S(1)(x) --> T(1)(y) intersystem crossing rate constant (k(ISC)) and the energy difference between the S(1)(x) and T(1)(y) states (DeltaE(S)(x)(T)(y)). In each of the Zn, Mg, and metal-free compounds, the Phi(Delta)/tau(F) values (tau(F): fluorescence lifetime), which are related to the k(ISC) values, are proportional to exp(-DeltaE(S)(x)(T)(y)), indicating that singlet oxygen ((1)Delta(g)) is produced via the T(1)(y) state and that the S(1)(x) --> T(1)(y) ISC process follows the energy-gap law. From the viewpoint of photodynamic therapy, our methodology

  17. The Structure and Assessment of a Unique and Popular Interdisciplinary Science Course for Nonmajors

    Science.gov (United States)

    Train, Tonya Laakko; Gammon, David E.

    2012-01-01

    Science Without Borders is a unique interdisciplinary science course that uses group and active-learning strategies and is in high demand among nonscience majors at a masters-level university. Registrar data showed that nonscience majors were far more likely to choose this course compared with other, discipline-based science courses. In an…

  18. A unique structure for the multiplexer in quantum-dot cellular automata to create a revolution in design of nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Naji Asfestani, Mazaher; Rasouli Heikalabad, Saeed, E-mail: s.rasouli@iaut.ac.ir

    2017-05-01

    Quantum-dot cellular automata (QCA) is the advent of technology and suitable replacement for semiconductor transistor technology. In this paper, a unique structure for the 2:1 multiplexer is presented in QCA. The structure of this component is simple, ultra-efficient and very useful to implement the various logical functions. The proposed structure does not follow any Boolean function. It takes advantage of the inherent characteristics of quantum technology to produce the desired output. Based on these principles, we design the new and efficient structures for the 4:1 multiplexer and 8:1 multiplexer in the QCA technology. These structures are designed with QCADesigner simulator and simulation results are examined. Investigation results indicate the amazing performance of proposed structure compared to existing structures in terms of area, complexity, power consumption and latency.

  19. Unique Reversible Crystal-to-Crystal Phase Transition – Structural and Functional Properties of Fused Ladder Thienoarenes

    KAUST Repository

    Abe, Yuichiro

    2017-08-15

    Donor-acceptor type molecules based on fused ladder thienoarenes, indacenodithiophene (IDT) and dithienocyclopenta-thienothiophene (DTCTT), coupled with benzothiadiazole, are prepared and their solid-state structures are investigated. They display a rich variety of solid phases ranging from amorphous glass states to crystalline states, upon changes in the central aromatic core and side group structures. Most notably, the DTCTT-based derivatives showed reversible crystal-to-crystal phase transitions in heating and cooling cycles. Unlike what has been seen in π−conjugated molecules variable temperature XRD revealed that structural change occurs continuously during the transition. A columnar self-assembled structure with slip-stacked π−π interaction is proposed to be involved in the solid-state. This research provides the evidence of unique structural behavior of the DTCTT-based molecules through the detailed structural analysis. This unique structural transition paves the way for these materials to have self-healing of crystal defects, leading to improved optoelectronic properties.

  20. Unique Reversible Crystal-to-Crystal Phase Transition – Structural and Functional Properties of Fused Ladder Thienoarenes

    KAUST Repository

    Abe, Yuichiro; Savikhin, Victoria; Yin, Jun; Grimsdale, Andrew C.; Soci, Cesare; Toney, Michael F.; Lam, Yeng Ming

    2017-01-01

    Donor-acceptor type molecules based on fused ladder thienoarenes, indacenodithiophene (IDT) and dithienocyclopenta-thienothiophene (DTCTT), coupled with benzothiadiazole, are prepared and their solid-state structures are investigated. They display a rich variety of solid phases ranging from amorphous glass states to crystalline states, upon changes in the central aromatic core and side group structures. Most notably, the DTCTT-based derivatives showed reversible crystal-to-crystal phase transitions in heating and cooling cycles. Unlike what has been seen in π−conjugated molecules variable temperature XRD revealed that structural change occurs continuously during the transition. A columnar self-assembled structure with slip-stacked π−π interaction is proposed to be involved in the solid-state. This research provides the evidence of unique structural behavior of the DTCTT-based molecules through the detailed structural analysis. This unique structural transition paves the way for these materials to have self-healing of crystal defects, leading to improved optoelectronic properties.

  1. Morchella tomentosa: a unique belowground structure and a new clade of morels

    Science.gov (United States)

    Franck O.P. Stefani; Serge Sokolski; Trish L. Wurtz; Yves Piché; Richard C. Hamelin; J. André Fortin; Jean A. Bérubé

    2010-01-01

    Mechanisms involved in post-fire morel fructification remain unclear. A new undescribed belowground vegetative structure of Marchella tomentosa in a burned boreal forest was investigated north of Fairbanks, Alaska. The name "radiscisclerotium" is proposed to define this peculiar and elaborate belowground vegetative structure of ...

  2. Micro-nano hierarchically structured nylon 6,6 surfaces with unique wettability.

    Science.gov (United States)

    Zhang, Liang; Zhang, Xiaoyan; Dai, Zhen; Wu, Junjie; Zhao, Ning; Xu, Jian

    2010-05-01

    A micro-nano hierarchically structured nylon 6,6 surface was easily fabricated by phase separation. Nylon 6,6 plate was swelled by formic acid and then immersed in a coagulate bath to precipitate. Micro particles with nano protrusions were generated and linked together covering over the surface. After dried up, the as-formed surface showed superhydrophilic ability. Inspired by lotus only employing 2-tier structure and ordinary plant wax to maintain superhydrophobicity, paraffin wax, a low surface energy material, was used to modify the hierarchically structured nylon 6,6 surface. The resultant surface had water contact angle (CA) of 155.2+/-1.3 degrees and a low sliding angle. The whole process was carried on under ambient condition and only need a few minutes. Copyright 2010 Elsevier Inc. All rights reserved.

  3. HOW SME UNIQUENESS AFFECTS CAPITAL STRUCTURE: EVIDENCE FROM A 1994-1998 SPANISH DATA PANEL

    OpenAIRE

    Francisco Sogorb- Mira

    2002-01-01

    The principal aim of this paper is to test how firm characteristics affect Small and Medium Enterprise (SME) capital structure. We carry out an empirical analysis over a panel data of 6482 non?financial Spanish SMEs along the five-year period 1994?1998, modelling the leverage ratio as a function of firm specific attributes hypothesized by capital structure theory. Our results suggest that non?debt tax shields and profitability are both negatively related to SME leverage, while size, growth op...

  4. Unique sail-like structure of cor triatriatum dexter in three-dimensional echocardiogram.

    Science.gov (United States)

    Low, Ting Ting; Uy, Celia Catherine C; Wong, Raymond Ching Chiew

    2014-08-01

    Cor triatriatum dexter (CTD) is an extremely rare congenital condition arising from the persistence of the right valve of the sinus venosus. It divides the right atrium (RA) into 2 separate chambers. We report a case of a 50-year-old man who had an incidental finding of CTD on transesophageal echocardiogram. An incomplete membrane of the RA was seen, and three-dimensional echocardiogram delineated the structure clearly as a triangular sail-like structure with multiple orifices and a fenestration. © 2013, Wiley Periodicals, Inc.

  5. Highly leukemogenic radiation leukemia virus isolate is a thymotropic, immunosuppressive retrovirus with a unique RNA structure

    Energy Technology Data Exchange (ETDEWEB)

    Ben David, Y.; Kotler, M.; Yefenof, E.

    1987-04-15

    Clones of N-, B- and NB-fibrotropic viruses were isolated from weakly (D-RadLV) and strongly (A-RadLV) leukomogenic RadLV preparations. A highly leukemogenic, thymotropic virus (TV) was isolated by ex-vivo infection of thymocytes with A-RadLV. This virus could not be isolated from D-RadLV. Two-dimensional fingerprint analysis suggested that TV recombines unique RNA sequences with RNA genomic material derived from a B-tropic endogenous virus. C57BL/6 (B6) mice injected with B- or NB-fibrotropic clones, but not with TV or N-tropic viral clones, developed reactive T lymphocytes (Tr), capable of differentiating into anti-tumor cytotoxic cells. The N-tropic virus isolates were non-immunogenic in B6 mice whereas the TV isolate induced suppressor T lymphocytes (Ts) that abrogated a potential Tr response. These results suggest that emergence of highly leukemogenic RadLV involves activation of endogenous fibrotropic virus which is immunogenic in its natural host strain (B6). This virus can further recombine with other retroviral genetic sequences, resulting in a suppressogenic and thymotropic, highly leukemogenic virus.

  6. O'nyong nyong virus molecular determinants of unique vector specificity reside in non-structural protein 3.

    Directory of Open Access Journals (Sweden)

    Kali D Saxton-Shaw

    Full Text Available O'nyong nyong virus (ONNV and Chikungunya virus (CHIKV are two closely related alphaviruses with very different infection patterns in the mosquito, Anopheles gambiae. ONNV is the only alphavirus transmitted by anopheline mosquitoes, but specific molecular determinants of infection of this unique vector specificity remain unidentified. Fifteen distinct chimeric viruses were constructed to evaluate both structural and non-structural regions of the genome and infection patterns were determined through artificial infectious feeds in An. gambiae with each of these chimeras. Only one region, non-structural protein 3 (nsP3, was sufficient to up-regulate infection to rates similar to those seen with parental ONNV. When ONNV non-structural protein 3 (nsP3 replaced nsP3 from CHIKV virus in one of the chimeric viruses, infection rates in An. gambiae went from 0% to 63.5%. No other single gene or viral region addition was able to restore infection rates. Thus, we have shown that a non-structural genome element involved in viral replication is a major element involved in ONNV's unique vector specificity.

  7. Unique mosaicism of structural chromosomal rearrangement: is chromosome 18 preferentially involved?

    NARCIS (Netherlands)

    Pater, J.M. de; Smeets, D.F.C.M.; Scheres, J.M.J.C.

    2003-01-01

    The mentally normal mother of a 4-year-old boy with del(18)(q21.3) syndrome was tested cytogenetically to study the possibility of an inherited structural rearrangement of chromosome 18. She was found to carry an unusual mosaicism involving chromosomes 18 and 21. Two unbalanced cell lines were seen

  8. Beyond the Lambertian limit: Novel low-symmetry gratings for ultimate light trapping enhancement in next-generation photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Birkmire, Robert [Univ. of Delaware, Newark, DE (United States); Hu, Juejun [Univ. of Delaware, Newark, DE (United States); Richardson, Kathleen [Univ. of Central Florida, Orlando, FL (United States). College of Optics and Photonics, Center for Research and Education in Optics and Lasers (CREOL)

    2016-05-20

    This project aims at addressing the efficiency limit and high fabrication cost of current light trapping methods by developing novel low-symmetry gratings (LSG) for next-generation thin c-Si photovoltaic (PV) cells. The LSG design achieves light trapping enhancement exceeding the 4n2 Lambertian limit and can be fabricated over large areas using low-cost, single-step nanoimprint techniques. We further explored the use of deposited high-refractive-index glass materials for low-temperature LSG processing, which enables direct imprint sculpting of even complex grating geometries in glass without requiring an additional pattern transfer step, which minimizes processing cost and surface damage to PV cells. In the project, we have demonstrated fabrication and integration of sub-wavelength LSG with thin c-Si wafers and bifacial solar cells with low defect density. Optical absorption measurements indicate that LSGs demonstrated superior absorption enhancement compared to their traditional symmetric counterparts as predicted by our simulations. Efficiency enhancement was observed in solar cells integrated with LSGs although fabrication yield of the LSG-integrated cells remains a challenge

  9. Unique Structural Modifications Are Present in the Lipopolysaccharide from Colistin-Resistant Strains of Acinetobacter baumannii

    Science.gov (United States)

    2013-10-01

    Selected reaction monitoring (SRM) studies were performed on a Thermo TSQ Quantum Ultra Triple Stage quadrupole mass spectrometer. The scans of the...well as a PmrC-dependent pEtN addition to the lipid A of E. coli O157:H7 (39). Surprisingly, the canine pathogen Capnocytophaga canimorsus and plant...variety of novel lipid A structures obtained from Francisella tula- rensis live vaccine strain. Innate Immun. 18:268 –278. 44. Balaji V, Jeremiah SS

  10. Unique C. elegans telomeric overhang structures reveal the evolutionarily conserved properties of telomeric DNA

    Czech Academy of Sciences Publication Activity Database

    Školáková, Petra; Foldynová-Trantírková, Silvie; Bednářová, Klára; Fiala, R.; Vorlíčková, Michaela; Trantírek, L.

    2015-01-01

    Roč. 43, č. 9 (2015), s. 4733-4745 ISSN 0305-1048 R&D Projects: GA ČR(CZ) GA13-28310S; GA ČR(CZ) GAP205/12/0466 Institutional support: RVO:68081707 ; RVO:60077344 Keywords : NUCLEASE HYPERSENSITIVE ELEMENT * G-QUADRUPLEX STRUCTURES * I-MOTIF Subject RIV: BO - Biophysics Impact factor: 9.202, year: 2015

  11. Human NOD2 Recognizes Structurally Unique Muramyl Dipeptides from Mycobacterium leprae.

    Science.gov (United States)

    Schenk, Mirjam; Mahapatra, Sebabrata; Le, Phuonganh; Kim, Hee Jin; Choi, Aaron W; Brennan, Patrick J; Belisle, John T; Modlin, Robert L

    2016-09-01

    The innate immune system recognizes microbial pathogens via pattern recognition receptors. One such receptor, NOD2, via recognition of muramyl dipeptide (MDP), triggers a distinct network of innate immune responses, including the production of interleukin-32 (IL-32), which leads to the differentiation of monocytes into dendritic cells (DC). NOD2 has been implicated in the pathogenesis of human leprosy, yet it is not clear whether Mycobacterium leprae, which has a distinct MDP structure, can activate this pathway. We investigated the effect of MDP structure on the innate immune response, finding that infection of monocytes with M. leprae induces IL-32 and DC differentiation in a NOD2-dependent manner. The presence of the proximal l-Ala instead of Gly in the common configuration of the peptide side chain of M. leprae did not affect recognition by NOD2 or cytokine production. Furthermore, amidation of the d-Glu residue did not alter NOD2 activation. These data provide experimental evidence that NOD2 recognizes naturally occurring structural variants of MDP. Copyright © 2016 Schenk et al.

  12. Structural, Bioinformatic, and In Vivo Analyses of Two Treponema pallidum Lipoproteins Reveal a Unique TRAP Transporter

    Energy Technology Data Exchange (ETDEWEB)

    Deka, Ranjit K.; Brautigam, Chad A.; Goldberg, Martin; Schuck, Peter; Tomchick, Diana R.; Norgard, Michael V. (NIH); (UTSMC)

    2012-05-25

    Treponema pallidum, the bacterial agent of syphilis, is predicted to encode one tripartite ATP-independent periplasmic transporter (TRAP-T). TRAP-Ts typically employ a periplasmic substrate-binding protein (SBP) to deliver the cognate ligand to the transmembrane symporter. Herein, we demonstrate that the genes encoding the putative TRAP-T components from T. pallidum, tp0957 (the SBP), and tp0958 (the symporter), are in an operon with an uncharacterized third gene, tp0956. We determined the crystal structure of recombinant Tp0956; the protein is trimeric and perforated by a pore. Part of Tp0956 forms an assembly similar to those of 'tetratricopeptide repeat' (TPR) motifs. The crystal structure of recombinant Tp0957 was also determined; like the SBPs of other TRAP-Ts, there are two lobes separated by a cleft. In these other SBPs, the cleft binds a negatively charged ligand. However, the cleft of Tp0957 has a strikingly hydrophobic chemical composition, indicating that its ligand may be substantially different and likely hydrophobic. Analytical ultracentrifugation of the recombinant versions of Tp0956 and Tp0957 established that these proteins associate avidly. This unprecedented interaction was confirmed for the native molecules using in vivo cross-linking experiments. Finally, bioinformatic analyses suggested that this transporter exemplifies a new subfamily of TPATs (TPR-protein-associated TRAP-Ts) that require the action of a TPR-containing accessory protein for the periplasmic transport of a potentially hydrophobic ligand(s).

  13. Syndecans as cell surface receptors: Unique structure equates with functional diversity

    DEFF Research Database (Denmark)

    Choi, Youngsil; Chung, Heesung; Jung, Heyjung

    2011-01-01

    An increasing number of functions for syndecan cell surface heparan sulfate proteoglycans have been proposed over the last decade. Moreover, aberrant syndecan regulation has been found to play a critical role in multiple pathologies, including cancers, as well as wound healing and inflammation....... As receptors, they have much in common with other molecules on the cell surface. Syndecans are type I transmembrane molecules with cytoplasmic domains that link to the actin cytoskeleton and can interact with a number of regulators. However, they are also highly complex by virtue of their external...... glycosaminoglycan chains, especially heparan sulfate. This heterodisperse polysaccharide has the potential to interact with many ligands from diverse protein families. Here, we relate the structural features of syndecans to some of their known functions....

  14. Novel Fluorinated Indanone, Tetralone and Naphthone Derivatives: Synthesis and Unique Structural Features

    Directory of Open Access Journals (Sweden)

    Joseph C. Sloop

    2012-02-01

    Full Text Available Several fluorinated and trifluoromethylated indanone, tetralone and naphthone derivatives have been prepared via Claisen condensations and selective fluorinations in yields ranging from 22–60%. In addition, we report the synthesis of new, selectively fluorinated bindones in yields ranging from 72–92%. Of particular interest is the fluorination and trifluoroacetylation regiochemistry observed in these fluorinated products. We also note unusual transformations including a novel one pot, dual trifluoroacetylation, trifluoroacetylnaphthone synthesis via a deacetylation as well as an acetyl-trifluoroacetyl group exchange. Solid-state structural features exhibited by these compounds were investigated using crystallographic methods. Crystallographic results, supported by spectroscopic data, show that trifluoroacetylated ketones prefer a chelated cis-enol form whereas fluorinated bindone products exist primarily as the cross-conjugated triketo form.

  15. Chordotonal organs in hemipteran insects: unique peripheral structures but conserved central organization revealed by comparative neuroanatomy.

    Science.gov (United States)

    Nishino, Hiroshi; Mukai, Hiromi; Takanashi, Takuma

    2016-12-01

    Hemipteran insects use sophisticated vibrational communications by striking body appendages on the substrate or by oscillating the abdominal tymbal. There has been, however, little investigation of sensory channels for processing vibrational signals. Using sensory nerve stainings and low invasive confocal analyses, we demonstrate the comprehensive neuronal mapping of putative vibration-responsive chordotonal organs (COs) in stink bugs (Pentatomidae and Cydinidae) and cicadas (Cicadidae). The femoral CO (FCO) in stink bugs consists of ventral and dorsal scoloparia, homologous to distal and proximal scoloparia in locusts, which are implicated in joint movement detection and vibration detection, respectively. The ligament of the dorsal scoloparium is distally attached to the accessory extensor muscle, whereas that of the ventral scoloparium is attached to a specialized tendon. Their afferents project to the dorso-lateral neuropil and the central region of the medial ventral association center (mVAC) in the ipsilateral neuromere, where presumed dorsal scoloparium afferents and subgenual organ afferents are largely intermingled. In contrast, FCOs in cicadas have decreased dorsal scoloparium neurons and lack projections to the mVAC. The tymbal CO of stink bugs contains four sensory neurons that are distally attached to fat body cells via a ligament. Their axons project intersegmentally to the dorsal region of mVACs in all neuromeres. Together with comparisons of COs in different insect groups, the results suggest that hemipteran COs have undergone structural modification for achieving faster signaling of resonating peripheral tissues. The conserved projection patterns of COs suggest functional importance of the FCO and subgenual organ for vibrational communications.

  16. Extensive genetic diversity, unique population structure and evidence of genetic exchange in the sexually transmitted parasite Trichomonas vaginalis.

    Directory of Open Access Journals (Sweden)

    Melissa D Conrad

    Full Text Available Trichomonas vaginalis is the causative agent of human trichomoniasis, the most common non-viral sexually transmitted infection world-wide. Despite its prevalence, little is known about the genetic diversity and population structure of this haploid parasite due to the lack of appropriate tools. The development of a panel of microsatellite makers and SNPs from mining the parasite's genome sequence has paved the way to a global analysis of the genetic structure of the pathogen and association with clinical phenotypes.Here we utilize a panel of T. vaginalis-specific genetic markers to genotype 235 isolates from Mexico, Chile, India, Australia, Papua New Guinea, Italy, Africa and the United States, including 19 clinical isolates recently collected from 270 women attending New York City sexually transmitted disease clinics. Using population genetic analysis, we show that T. vaginalis is a genetically diverse parasite with a unique population structure consisting of two types present in equal proportions world-wide. Parasites belonging to the two types (type 1 and type 2 differ significantly in the rate at which they harbor the T. vaginalis virus, a dsRNA virus implicated in parasite pathogenesis, and in their sensitivity to the widely-used drug, metronidazole. We also uncover evidence of genetic exchange, indicating a sexual life-cycle of the parasite despite an absence of morphologically-distinct sexual stages.Our study represents the first robust and comprehensive evaluation of global T. vaginalis genetic diversity and population structure. Our identification of a unique two-type structure, and the clinically relevant phenotypes associated with them, provides a new dimension for understanding T. vaginalis pathogenesis. In addition, our demonstration of the possibility of genetic exchange in the parasite has important implications for genetic research and control of the disease.

  17. Extensive genetic diversity, unique population structure and evidence of genetic exchange in the sexually transmitted parasite Trichomonas vaginalis.

    Science.gov (United States)

    Conrad, Melissa D; Gorman, Andrew W; Schillinger, Julia A; Fiori, Pier Luigi; Arroyo, Rossana; Malla, Nancy; Dubey, Mohan Lal; Gonzalez, Jorge; Blank, Susan; Secor, William E; Carlton, Jane M

    2012-01-01

    Trichomonas vaginalis is the causative agent of human trichomoniasis, the most common non-viral sexually transmitted infection world-wide. Despite its prevalence, little is known about the genetic diversity and population structure of this haploid parasite due to the lack of appropriate tools. The development of a panel of microsatellite makers and SNPs from mining the parasite's genome sequence has paved the way to a global analysis of the genetic structure of the pathogen and association with clinical phenotypes. Here we utilize a panel of T. vaginalis-specific genetic markers to genotype 235 isolates from Mexico, Chile, India, Australia, Papua New Guinea, Italy, Africa and the United States, including 19 clinical isolates recently collected from 270 women attending New York City sexually transmitted disease clinics. Using population genetic analysis, we show that T. vaginalis is a genetically diverse parasite with a unique population structure consisting of two types present in equal proportions world-wide. Parasites belonging to the two types (type 1 and type 2) differ significantly in the rate at which they harbor the T. vaginalis virus, a dsRNA virus implicated in parasite pathogenesis, and in their sensitivity to the widely-used drug, metronidazole. We also uncover evidence of genetic exchange, indicating a sexual life-cycle of the parasite despite an absence of morphologically-distinct sexual stages. Our study represents the first robust and comprehensive evaluation of global T. vaginalis genetic diversity and population structure. Our identification of a unique two-type structure, and the clinically relevant phenotypes associated with them, provides a new dimension for understanding T. vaginalis pathogenesis. In addition, our demonstration of the possibility of genetic exchange in the parasite has important implications for genetic research and control of the disease.

  18. Crystal structure of lactose permease in complex with an affinity inactivator yields unique insight into sugar recognition

    Energy Technology Data Exchange (ETDEWEB)

    Chaptal, Vincent; Kwon, Seunghyug; Sawaya, Michael R.; Guan, Lan; Kaback, H. Ronald; Abramson, Jeff (UCLA); (TTU)

    2011-08-29

    Lactose permease of Escherichia coli (LacY) with a single-Cys residue in place of A122 (helix IV) transports galactopyranosides and is specifically inactivated by methanethiosulfonyl-galactopyranosides (MTS-gal), which behave as unique suicide substrates. In order to study the mechanism of inactivation more precisely, we solved the structure of single-Cys122 LacY in complex with covalently bound MTS-gal. This structure exhibits an inward-facing conformation similar to that observed previously with a slight narrowing of the cytoplasmic cavity. MTS-gal is bound covalently, forming a disulfide bond with C122 and positioned between R144 and W151. E269, a residue essential for binding, coordinates the C-4 hydroxyl of the galactopyranoside moiety. The location of the sugar is in accord with many biochemical studies.

  19. Plutonium uniqueness

    International Nuclear Information System (INIS)

    Silver, G.L.

    1984-01-01

    A standard is suggested against which the putative uniqueness of plutonium may be tested. It is common folklore that plutonium is unique among the chemical elements because its four common oxidation states can coexist in the same solution. Whether this putative uniqueness appears only during transit to equilibrium, or only at equilibrium, or all of the time, is not generally made clear. But while the folklore may contain some truth, it cannot be put to test until some measure of 'uniqueness' is agreed upon so that quantitative comparisons are possible. One way of measuring uniqueness is as the magnitude of the product of the mole fractions of the element at equilibrium. A 'coexistence index' is defined and discussed. (author)

  20. Discrete and structurally unique proteins (tāpirins) mediate attachment of extremely thermophilic Caldicellulosiruptor species to cellulose.

    Science.gov (United States)

    Blumer-Schuette, Sara E; Alahuhta, Markus; Conway, Jonathan M; Lee, Laura L; Zurawski, Jeffrey V; Giannone, Richard J; Hettich, Robert L; Lunin, Vladimir V; Himmel, Michael E; Kelly, Robert M

    2015-04-24

    A variety of catalytic and noncatalytic protein domains are deployed by select microorganisms to deconstruct lignocellulose. These extracellular proteins are used to attach to, modify, and hydrolyze the complex polysaccharides present in plant cell walls. Cellulolytic enzymes, often containing carbohydrate-binding modules, are key to this process; however, these enzymes are not solely responsible for attachment. Few mechanisms of attachment have been discovered among bacteria that do not form large polypeptide structures, called cellulosomes, to deconstruct biomass. In this study, bioinformatics and proteomics analyses identified unique, discrete, hypothetical proteins ("tāpirins," origin from Māori: to join), not directly associated with cellulases, that mediate attachment to cellulose by species in the noncellulosomal, extremely thermophilic bacterial genus Caldicellulosiruptor. Two tāpirin genes are located directly downstream of a type IV pilus operon in strongly cellulolytic members of the genus, whereas homologs are absent from the weakly cellulolytic Caldicellulosiruptor species. Based on their amino acid sequence, tāpirins are specific to these extreme thermophiles. Tāpirins are also unusual in that they share no detectable protein domain signatures with known polysaccharide-binding proteins. Adsorption isotherm and trans vivo analyses demonstrated the carbohydrate-binding module-like affinity of the tāpirins for cellulose. Crystallization of a cellulose-binding truncation from one tāpirin indicated that these proteins form a long β-helix core with a shielded hydrophobic face. Furthermore, they are structurally unique and define a new class of polysaccharide adhesins. Strongly cellulolytic Caldicellulosiruptor species employ tāpirins to complement substrate-binding proteins from the ATP-binding cassette transporters and multidomain extracellular and S-layer-associated glycoside hydrolases to process the carbohydrate content of lignocellulose.

  1. Structure of the large terminase from a hyperthermophilic virus reveals a unique mechanism for oligomerization and ATP hydrolysis.

    Science.gov (United States)

    Xu, Rui-Gang; Jenkins, Huw T; Antson, Alfred A; Greive, Sandra J

    2017-12-15

    The crystal structure of the large terminase from the Geobacillus stearothermophilus bacteriophage D6E shows a unique relative orientation of the N-terminal adenosine triphosphatase (ATPase) and C-terminal nuclease domains. This monomeric 'initiation' state with the two domains 'locked' together is stabilized via a conserved C-terminal arm, which may interact with the portal protein during motor assembly, as predicted for several bacteriophages. Further work supports the formation of an active oligomeric state: (i) AUC data demonstrate the presence of oligomers; (ii) mutational analysis reveals a trans-arginine finger, R158, indispensable for ATP hydrolysis; (iii) the location of this arginine is conserved with the HerA/FtsK ATPase superfamily; (iv) a molecular docking model of the pentamer is compatible with the location of the identified arginine finger. However, this pentameric model is structurally incompatible with the monomeric 'initiation' state and is supported by the observed increase in kcat of ATP hydrolysis, from 7.8 ± 0.1 min-1 to 457.7 ± 9.2 min-1 upon removal of the C-terminal nuclease domain. Taken together, these structural, biophysical and biochemical data suggest a model where transition from the 'initiation' state into a catalytically competent pentameric state, is accompanied by substantial domain rearrangements, triggered by the removal of the C-terminal arm from the ATPase active site. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  2. Hepatic crown-like structure: a unique histological feature in non-alcoholic steatohepatitis in mice and humans.

    Directory of Open Access Journals (Sweden)

    Michiko Itoh

    Full Text Available Although macrophages are thought to be crucial for the pathogenesis of chronic inflammatory diseases, how they are involved in disease progression from simple steatosis to non-alcoholic steatohepatitis (NASH is poorly understood. Here we report the unique histological structure termed "hepatic crown-like structures (hCLS" in the mouse model of human NASH; melanocortin-4 receptor deficient mice fed a Western diet. In hCLS, CD11c-positive macrophages aggregate to surround hepatocytes with large lipid droplets, which is similar to those described in obese adipose tissue. Histological analysis revealed that hCLS is closely associated with activated fibroblasts and collagen deposition. When treatment with clodronate liposomes effectively depletes macrophages scattered in the liver, with those in hCLS intact, hepatic expression of inflammatory and fibrogenic genes is unaffected, suggesting that hCLS is an important source of inflammation and fibrosis during the progression of NASH. Notably, the number of hCLS is positively correlated with the extent of liver fibrosis. We also observed increased number of hCLS in the liver of non-alcoholic fatty liver disease/NASH patients. Collectively, our data provide evidence that hCLS is involved in the development of hepatic inflammation and fibrosis, thereby suggesting its pathophysiologic role in disease progression from simple steatosis to NASH.

  3. A Novel Carbohydrate-binding Module from Sugar Cane Soil Metagenome Featuring Unique Structural and Carbohydrate Affinity Properties*

    Science.gov (United States)

    Campos, Bruna Medeia; Alvarez, Thabata Maria; Zanphorlin, Letícia Maria; Ematsu, Gabriela Cristina; Barud, Hernane; Polikarpov, Igor; Ruller, Roberto; Gilbert, Harry J.; Zeri, Ana Carolina de Mattos; Squina, Fabio Marcio

    2016-01-01

    Carbohydrate-binding modules (CBMs) are appended to glycoside hydrolases and can contribute to the degradation of complex recalcitrant substrates such as the plant cell wall. For application in bioethanol production, novel enzymes with high catalytic activity against recalcitrant lignocellulosic material are being explored and developed. In this work, we report the functional and structural study of CBM_E1, which was discovered through a metagenomics approach and is the founding member of a novel CBM family, CBM81. CBM_E1, which is linked to an endoglucanase, displayed affinity for mixed linked β1,3-β1,4-glucans, xyloglucan, Avicel, and cellooligosaccharides. The crystal structure of CBM_E1 in complex with cellopentaose displayed a canonical β-sandwich fold comprising two β-sheets. The planar ligand binding site, observed in a parallel orientation with the β-strands, is a typical feature of type A CBMs, although the expected affinity for bacterial crystalline cellulose was not detected. Conversely, the binding to soluble glucans was enthalpically driven, which is typical of type B modules. These unique properties of CBM_E1 are at the interface between type A and type B CBMs. PMID:27621314

  4. Structural analysis and unique molecular recognition properties of a Bauhinia forficata lectin that inhibits cancer cell growth.

    Science.gov (United States)

    Lubkowski, Jacek; Durbin, Sarah V; Silva, Mariana C C; Farnsworth, David; Gildersleeve, Jeffrey C; Oliva, Maria Luiza V; Wlodawer, Alexander

    2017-02-01

    Lectins have been used at length for basic research and clinical applications. New insights into the molecular recognition properties enhance our basic understanding of carbohydrate-protein interactions and aid in the design/development of new lectins. In this study, we used a combination of cell-based assays, glycan microarrays, and X-ray crystallography to evaluate the structure and function of the recombinant Bauhinia forficata lectin (BfL). The lectin was shown to be cytostatic for several cancer cell lines included in the NCI-60 panel; in particular, it inhibited growth of melanoma cancer cells (LOX IMVI) by over 95%. BfL is dimeric in solution and highly specific for binding of oligosaccharides and glycopeptides with terminal N-acetylgalactosamine (GalNAc). BfL was found to have especially strong binding (apparent K d  = 0.5-1.0 nm) to the tumor-associated Tn antigen. High-resolution crystal structures were determined for the ligand-free lectin, as well as for its complexes with three Tn glycopeptides, globotetraose, and the blood group A antigen. Extensive analysis of the eight crystal structures and comparison to structures of related lectins revealed several unique features of GalNAc recognition. Of special note, the carboxylate group of Glu126, lining the glycan-binding pocket, forms H-bonds with both the N-acetyl of GalNAc and the peptide amido group of Tn antigens. Stabilization provided by Glu126 is described here for the first time for any GalNAc-specific lectin. Taken together, the results provide new insights into the molecular recognition of carbohydrates and provide a structural understanding that will enable rational engineering of BfL for a variety of applications. Structural data are available in the PDB under the accession numbers 5T50, 5T52, 5T55, 5T54, 5T5L, 5T5J, 5T5P, and 5T5O. © 2016 Federation of European Biochemical Societies.

  5. Two unique ligand-binding clamps of Rhizopus oryzae starch binding domain for helical structure disruption of amylose.

    Directory of Open Access Journals (Sweden)

    Ting-Ying Jiang

    Full Text Available The N-terminal starch binding domain of Rhizopus oryzae glucoamylase (RoSBD has a high binding affinity for raw starch. RoSBD has two ligand-binding sites, each containing a ligand-binding clamp: a polyN clamp residing near binding site I is unique in that it is expressed in only three members of carbohydrate binding module family 21 (CBM21 members, and a Y32/F58 clamp located at binding site II is conserved in several CBMs. Here we characterized different roles of these sites in the binding of insoluble and soluble starches using an amylose-iodine complex assay, atomic force microscopy, isothermal titration calorimetry, site-directed mutagenesis, and structural bioinformatics. RoSBD induced the release of iodine from the amylose helical cavity and disrupted the helical structure of amylose type III, thereby significantly diminishing the thickness and length of the amylose type III fibrils. A point mutation in the critical ligand-binding residues of sites I and II, however, reduced both the binding affinity and amylose helix disruption. This is the first molecular model for structure disruption of the amylose helix by a non-hydrolytic CBM21 member. RoSBD apparently twists the helical amylose strands apart to expose more ligand surface for further SBD binding. Repeating the process triggers the relaxation and unwinding of amylose helices to generate thinner and shorter amylose fibrils, which are more susceptible to hydrolysis by glucoamylase. This model aids in understanding the natural roles of CBMs in protein-glycan interactions and contributes to potential molecular engineering of CBMs.

  6. Structural characterization of the bacterial proteasome homolog BPH reveals a tetradecameric double-ring complex with unique inner cavity properties.

    Science.gov (United States)

    Fuchs, Adrian C D; Maldoner, Lorena; Hipp, Katharina; Hartmann, Marcus D; Martin, Jörg

    2018-01-19

    Eukaryotic and archaeal proteasomes are paradigms for self-compartmentalizing proteases. To a large extent, their function requires interplay with hexameric ATPases associated with diverse cellular activities (AAA+) that act as substrate unfoldases. Bacteria have various types of self-compartmentalizing proteases; in addition to the proteasome itself, these include the proteasome homolog HslV, which functions together with the AAA+ HslU; the ClpP protease with its partner AAA+ ClpX; and Anbu, a recently characterized ancestral proteasome variant. Previous bioinformatic analysis has revealed a novel bacterial member of the proteasome family Betaproteobacteria proteasome homolog (BPH). Using cluster analysis, we here affirmed that BPH evolutionarily descends from HslV. Crystal structures of the Thiobacillus denitrificans and Cupriavidus metallidurans BPHs disclosed a homo-oligomeric double-ring architecture in which the active sites face the interior of the cylinder. Using small-angle X-ray scattering (SAXS) and electron microscopy averaging, we found that BPH forms tetradecamers in solution, unlike the dodecamers seen in HslV. Although the highly acidic inner surface of BPH was in striking contrast to the cavity characteristics of the proteasome and HslV, a classical proteasomal reaction mechanism could be inferred from the covalent binding of the proteasome-specific inhibitor epoxomicin to BPH. A ligand-bound structure implied that the elongated BPH inner pore loop may be involved in substrate recognition. The apparent lack of a partner unfoldase and other unique features, such as Ser replacing Thr as the catalytic residue in certain BPH subfamilies, suggest a proteolytic function for BPH distinct from those of known bacterial self-compartmentalizing proteases. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Structural characterization of a unique marine animal family 7 cellobiohydrolase suggests a mechanism of cellulase salt tolerance.

    Science.gov (United States)

    Kern, Marcelo; McGeehan, John E; Streeter, Simon D; Martin, Richard N A; Besser, Katrin; Elias, Luisa; Eborall, Will; Malyon, Graham P; Payne, Christina M; Himmel, Michael E; Schnorr, Kirk; Beckham, Gregg T; Cragg, Simon M; Bruce, Neil C; McQueen-Mason, Simon J

    2013-06-18

    Nature uses a diversity of glycoside hydrolase (GH) enzymes to convert polysaccharides to sugars. As lignocellulosic biomass deconstruction for biofuel production remains costly, natural GH diversity offers a starting point for developing industrial enzymes, and fungal GH family 7 (GH7) cellobiohydrolases, in particular, provide significant hydrolytic potential in industrial mixtures. Recently, GH7 enzymes have been found in other kingdoms of life besides fungi, including in animals and protists. Here, we describe the in vivo spatial expression distribution, properties, and structure of a unique endogenous GH7 cellulase from an animal, the marine wood borer Limnoria quadripunctata (LqCel7B). RT-quantitative PCR and Western blot studies show that LqCel7B is expressed in the hepatopancreas and secreted into the gut for wood degradation. We produced recombinant LqCel7B, with which we demonstrate that LqCel7B is a cellobiohydrolase and obtained four high-resolution crystal structures. Based on a crystallographic and computational comparison of LqCel7B to the well-characterized Hypocrea jecorina GH7 cellobiohydrolase, LqCel7B exhibits an extended substrate-binding motif at the tunnel entrance, which may aid in substrate acquisition and processivity. Interestingly, LqCel7B exhibits striking surface charges relative to fungal GH7 enzymes, which likely results from evolution in marine environments. We demonstrate that LqCel7B stability and activity remain unchanged, or increase at high salt concentration, and that the L. quadripunctata GH mixture generally contains cellulolytic enzymes with highly acidic surface charge compared with enzymes derived from terrestrial microbes. Overall, this study suggests that marine cellulases offer significant potential for utilization in high-solids industrial biomass conversion processes.

  8. Structural and biochemical analysis of a unique phosphatase from Bdellovibrio bacteriovorus reveals its structural and functional relationship with the protein tyrosine phosphatase class of phytase.

    Directory of Open Access Journals (Sweden)

    Robert J Gruninger

    Full Text Available Bdellovibrio bacteriovorus is an unusual δ-proteobacterium that invades and preys on other Gram-negative bacteria and is of potential interest as a whole cell therapeutic against pathogens of man, animals and crops. PTPs (protein tyrosine phosphatases are an important class of enzyme involved in desphosphorylating a variety of substrates, often with implications in cell signaling. The B. bacteriovorus open reading frame Bd1204 is predicted to encode a PTP of unknown function. Bd1204 is both structurally and mechanistically related to the PTP-like phytase (PTPLP class of enzymes and possesses a number of unique properties not observed in any other PTPLPs characterized to date. Bd1204 does not display catalytic activity against some common protein tyrosine phosphatase substrates but is highly specific for hydrolysis of phosphomonoester bonds of inositol hexakisphosphate. The structure reveals that Bd1204 has the smallest and least electropositive active site of all characterized PTPLPs to date yet possesses a unique substrate specificity characterized by a strict preference for inositol hexakisphosphate. These two active site features are believed to be the most significant contributors to the specificity of phytate degrading enzymes. We speculate that Bd1204 may be involved in phosphate acquisition outside of prey.

  9. Participatory role of zinc in structural and functional characterization of bioremediase: a unique thermostable microbial silica leaching protein.

    Science.gov (United States)

    Chowdhury, Trinath; Sarkar, Manas; Chaudhuri, Biswadeep; Chattopadhyay, Brajadulal; Halder, Umesh Chandra

    2015-07-01

    A unique protein, bioremediase (UniProt Knowledgebase Accession No.: P86277), isolated from a hot spring bacterium BKH1 (GenBank Accession No.: FJ177512), has shown to exhibit silica leaching activity when incorporated to prepare bio-concrete material. Matrix-assisted laser desorption ionization mass spectrometry analysis suggests that bioremediase is 78% homologous to bovine carbonic anhydrase II though it does not exhibit carbonic anhydrase-like activity. Bioinformatics study is performed for understanding the various physical and chemical parameters of the protein which predicts the involvement of zinc encircled by three histidine residues (His94, His96 and His119) at the active site of the protein. Isothermal titration calorimetric-based thermodynamic study on diethyl pyrocarbonate-modified protein recognizes the presence of Zn(2+) in the enzyme moiety. Exothermic to endothermic transition as observed during titration of the protein with Zn(2+) discloses that there are at least two binding sites for zinc within the protein moiety. Addition of Zn(2+) regains the activity of EDTA chelated bioremediase confirming the presence of extra binding site of Zn(2+) in the protein moiety. Revival of folding pattern of completely unfolded urea-treated protein by Zn(2+) explains the participatory role of zinc in structural stability of the protein. Restoration of the λ max in intrinsic fluorescence emission study of the urea-treated protein by Zn(2+) similarly confirms the involvement of Zn in the refolding of the protein. The utility of bioremediase for silica nanoparticles preparation is observed by field emission scanning electron microscopy.

  10. A Validation Study of the Rank-Preserving Structural Failure Time Model: Confidence Intervals and Unique, Multiple, and Erroneous Solutions.

    Science.gov (United States)

    Ouwens, Mario; Hauch, Ole; Franzén, Stefan

    2018-05-01

    The rank-preserving structural failure time model (RPSFTM) is used for health technology assessment submissions to adjust for switching patients from reference to investigational treatment in cancer trials. It uses counterfactual survival (survival when only reference treatment would have been used) and assumes that, at randomization, the counterfactual survival distribution for the investigational and reference arms is identical. Previous validation reports have assumed that patients in the investigational treatment arm stay on therapy throughout the study period. To evaluate the validity of the RPSFTM at various levels of crossover in situations in which patients are taken off the investigational drug in the investigational arm. The RPSFTM was applied to simulated datasets differing in percentage of patients switching, time of switching, underlying acceleration factor, and number of patients, using exponential distributions for the time on investigational and reference treatment. There were multiple scenarios in which two solutions were found: one corresponding to identical counterfactual distributions, and the other to two different crossing counterfactual distributions. The same was found for the hazard ratio (HR). Unique solutions were observed only when switching patients were on investigational treatment for <40% of the time that patients in the investigational arm were on treatment. Distributions other than exponential could have been used for time on treatment. An HR equal to 1 is a necessary but not always sufficient condition to indicate acceleration factors associated with equal counterfactual survival. Further assessment to distinguish crossing counterfactual curves from equal counterfactual curves is especially needed when the time that switchers stay on investigational treatment is relatively long compared to the time direct starters stay on investigational treatment.

  11. Requirement of lid2 for interfacial activation of a family I.3 lipase with unique two lid structures.

    Science.gov (United States)

    Cheng, Maria; Angkawidjaja, Clement; Koga, Yuichi; Kanaya, Shigenori

    2012-10-01

    A family I.3 lipase from Pseudomonas sp. MIS38 (PML) is characterized by the presence of two lids (lid1 and lid2) that greatly change conformation upon substrate binding. While lid1 represents the commonly known lid in lipases, lid2 is unique to PML and other family I.3 lipases. To clarify the role of lid2 in PML, a lid2 deletion mutant (ΔL2-PML) was constructed by deleting residues 35-64 of PML. ΔL2-PML requires calcium ions for both lipase and esterase activities as does PML, suggesting that it exhibits activity only when lid1 is fully open and anchored by the catalytically essential calcium ion, as does PML. However, when the enzymatic activity was determined using triacetin, the activity of PML exponentially increased as the substrate concentration reached and increased beyond the critical micellar concentration, while that of ΔL2-PML did not. These results indicate that PML undergoes interfacial activation, while ΔL2-PML does not. The activities of ΔL2-PML for long-chain triglycerides significantly decreased while its activity for fatty acid ethyl esters increased, compared with those of PML. Comparison of the tertiary models of ΔL2-PML in a closed and open conformation, which are optimized by molecular dynamics simulation, with the crystal structures of PML suggests that the hydrophobic surface area provided by lid1 and lid2 in an open conformation is considerably decreased by the deletion of lid2. We propose that the hydrophobic surface area provided by these lids is necessary to hold the micellar substrates firmly to the active site and therefore lid2 is required for interfacial activation of PML. © 2012 The Authors Journal compilation © 2012 FEBS.

  12. The unique architecture and function of cellulose-interacting proteins in oomycetes revealed by genomic and structural analyses

    Directory of Open Access Journals (Sweden)

    Larroque Mathieu

    2012-11-01

    Full Text Available Abstract Background Oomycetes are fungal-like microorganisms evolutionary distinct from true fungi, belonging to the Stramenopile lineage and comprising major plant pathogens. Both oomycetes and fungi express proteins able to interact with cellulose, a major component of plant and oomycete cell walls, through the presence of carbohydrate-binding module belonging to the family 1 (CBM1. Fungal CBM1-containing proteins were implicated in cellulose degradation whereas in oomycetes, the Cellulose Binding Elicitor Lectin (CBEL, a well-characterized CBM1-protein from Phytophthora parasitica, was implicated in cell wall integrity, adhesion to cellulosic substrates and induction of plant immunity. Results To extend our knowledge on CBM1-containing proteins in oomycetes, we have conducted a comprehensive analysis on 60 fungi and 7 oomycetes genomes leading to the identification of 518 CBM1-containing proteins. In plant-interacting microorganisms, the larger number of CBM1-protein coding genes is expressed by necrotroph and hemibiotrophic pathogens, whereas a strong reduction of these genes is observed in symbionts and biotrophs. In fungi, more than 70% of CBM1-containing proteins correspond to enzymatic proteins in which CBM1 is associated with a catalytic unit involved in cellulose degradation. In oomycetes more than 90% of proteins are similar to CBEL in which CBM1 is associated with a non-catalytic PAN/Apple domain, known to interact with specific carbohydrates or proteins. Distinct Stramenopile genomes like diatoms and brown algae are devoid of CBM1 coding genes. A CBM1-PAN/Apple association 3D structural modeling was built allowing the identification of amino acid residues interacting with cellulose and suggesting the putative interaction of the PAN/Apple domain with another type of glucan. By Surface Plasmon Resonance experiments, we showed that CBEL binds to glycoproteins through galactose or N-acetyl-galactosamine motifs. Conclusions This study

  13. Crystal structure of Aquifex aeolicus gene product Aq1627: a putative phosphoglucosamine mutase reveals a unique C-terminal end-to-end disulfide linkage.

    Science.gov (United States)

    Sridharan, Upasana; Kuramitsu, Seiki; Yokoyama, Shigeyuki; Kumarevel, Thirumananseri; Ponnuraj, Karthe

    2017-06-27

    The Aq1627 gene from Aquifex aeolicus, a hyperthermophilic bacterium has been cloned and overexpressed in Escherichia coli. The protein was purified to homogeneity and its X-ray crystal structure was determined to 1.3 Å resolution using multiple wavelength anomalous dispersion phasing. The structural and sequence analysis of Aq1627 is suggestive of a putative phosphoglucosamine mutase. The structural features of Aq1627 further indicate that it could belong to a new subclass of the phosphoglucosamine mutase family. Aq1627 structure contains a unique C-terminal end-to-end disulfide bond, which links two monomers and this structural information can be used in protein engineering to make proteins more stable in different applications.

  14. 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.

  15. The structural chemistry of metallocorroles: combined X-ray crystallography and quantum chemistry studies afford unique insights.

    Science.gov (United States)

    Thomas, Kolle E; Alemayehu, Abraham B; Conradie, Jeanet; Beavers, Christine M; Ghosh, Abhik

    2012-08-21

    Although they share some superficial structural similarities with porphyrins, corroles, trianionic ligands with contracted cores, give rise to fundamentally different transition metal complexes in comparison with the dianionic porphyrins. Many metallocorroles are formally high-valent, although a good fraction of them are also noninnocent, with significant corrole radical character. These electronic-structural characteristics result in a variety of fascinating spectroscopic behavior, including highly characteristic, paramagnetically shifted NMR spectra and textbook cases of charge-transfer spectra. Although our early research on corroles focused on spectroscopy, we soon learned that the geometric structures of metallocorroles provide a fascinating window into their electronic-structural characteristics. Thus, we used X-ray structure determinations and quantum chemical studies, chiefly using DFT, to obtain a comprehensive understanding of metallocorrole geometric and electronic structures. This Account describes our studies of the structural chemistry of metallocorroles. At first blush, the planar or mildly domed structure of metallocorroles might appear somewhat uninteresting particularly when compared to metalloporphyrins. Metalloporphyrins, especially sterically hindered ones, are routinely ruffled or saddled, but the missing meso carbon apparently makes the corrole skeleton much more resistant to nonplanar distortions. Ruffling, where the pyrrole rings are alternately twisted about the M-N bonds, is energetically impossible for metallocorroles. Saddling is also uncommon; thus, a number of sterically hindered, fully substituted metallocorroles exhibit almost perfectly planar macrocycle cores. Against this backdrop, copper corroles stand out as an important exception. As a result of an energetically favorable Cu(d(x2-y2))-corrole(π) orbital interaction, copper corroles, even sterically unhindered ones, are inherently saddled. Sterically hindered substituents

  16. The unique hemoglobin system of Pleuragramma antarcticum, an antarctic migratory teleost. Structure and function of the three components.

    Science.gov (United States)

    Tamburrini, M; D'Avino, R; Fago, A; Carratore, V; Kunzmann, A; Prisco, G

    1996-09-27

    Pleuragramma antarcticum (suborder Notothenioidei, family Nototheniidae) is the most abundant fish in the antarctic shelf. This pelagic species has a circum-antarctic distribution and is characterized by spawning migration. This species displays the highest multiplicity of major hemoglobins (three); the other notothenioids have a single one (except one species, having two) with relatively low oxygen affinity regulated by pH and organophosphates. The hemoglobins of P. antarcticum display strong Bohr and Root effects; however, they reveal important functional differences in subunit cooperativity and organophosphate regulation and, above all, in the response of oxygenation to temperature. Despite the substitution ValbetaE11 --> Ile found in Hb 2, which decreases the affinity in human mutants, the hemoglobins have similar oxygen affinity, higher than that of the other notothenioids. Hb 1 has the alpha chain in common with Hb 2 and the beta in common with Hb 3. The amino acid sequence of all four chains has been established. Thus the hematological features of P. antarcticum differ remarkably from those of antarctic notothenioids. This unique and sophisticated oxygen transport system may adequately meet the requirements of the unusual mode of life of this fish.

  17. Human HDAC isoform selectivity achieved via exploitation of the acetate release channel with structurally unique small molecule inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, Lewis; Dobler, Markus R.; Radetich, Branko; Zhu, Yanyi; Atadja, Peter W.; Claiborne, Tavina; Grob, Jonathan E.; McRiner, Andrew; Pancost, Margaret R.; Patnaik, Anup; Shao, Wenlin; Shultz, Michael; Tichkule, Ritesh; Tommasi, Ruben A.; Vash, Brian; Wang, Ping; Stams, Travis (Novartis)

    2013-11-20

    Herein we report the discovery of a family of novel yet simple, amino-acid derived class I HDAC inhibitors that demonstrate isoform selectivity via access to the internal acetate release channel. Isoform selectivity criteria is discussed on the basis of X-ray crystallography and molecular modeling of these novel inhibitors bound to HDAC8, potentially revealing insights into the mechanism of enzymatic function through novel structural features revealed at the atomic level.

  18. F-Type Lectins: A Highly Diversified Family of Fucose-Binding Proteins with a Unique Sequence Motif and Structural Fold, Involved in Self/Non-Self-Recognition

    Directory of Open Access Journals (Sweden)

    Gerardo R. Vasta

    2017-11-01

    Full Text Available The F-type lectin (FTL family is one of the most recent to be identified and structurally characterized. Members of the FTL family are characterized by a fucose recognition domain [F-type lectin domain (FTLD] that displays a novel jellyroll fold (“F-type” fold and unique carbohydrate- and calcium-binding sequence motifs. This novel lectin family comprises widely distributed proteins exhibiting single, double, or greater multiples of the FTLD, either tandemly arrayed or combined with other structurally and functionally distinct domains, yielding lectin subunits of pleiotropic properties even within a single species. Furthermore, the extraordinary variability of FTL sequences (isoforms that are expressed in a single individual has revealed genetic mechanisms of diversification in ligand recognition that are unique to FTLs. Functions of FTLs in self/non-self-recognition include innate immunity, fertilization, microbial adhesion, and pathogenesis, among others. In addition, although the F-type fold is distinctive for FTLs, a structure-based search revealed apparently unrelated proteins with minor sequence similarity to FTLs that displayed the FTLD fold. In general, the phylogenetic analysis of FTLD sequences from viruses to mammals reveals clades that are consistent with the currently accepted taxonomy of extant species. However, the surprisingly discontinuous distribution of FTLDs within each taxonomic category suggests not only an extensive structural/functional diversification of the FTLs along evolutionary lineages but also that this intriguing lectin family has been subject to frequent gene duplication, secondary loss, lateral transfer, and functional co-option.

  19. Unique structure and stability of HmuY, a novel heme-binding protein of Porphyromonas gingivalis.

    Directory of Open Access Journals (Sweden)

    Halina Wójtowicz

    2009-05-01

    Full Text Available Infection, survival, and proliferation of pathogenic bacteria in humans depend on their capacity to impair host responses and acquire nutrients in a hostile environment. Among such nutrients is heme, a co-factor for oxygen storage, electron transport, photosynthesis, and redox biochemistry, which is indispensable for life. Porphyromonas gingivalis is the major human bacterial pathogen responsible for severe periodontitis. It recruits heme through HmuY, which sequesters heme from host carriers and delivers it to its cognate outer-membrane transporter, the TonB-dependent receptor HmuR. Here we report that heme binding does not significantly affect the secondary structure of HmuY. The crystal structure of heme-bound HmuY reveals a new all-beta fold mimicking a right hand. The thumb and fingers pinch heme iron through two apical histidine residues, giving rise to highly symmetric octahedral iron co-ordination. The tetrameric quaternary arrangement of the protein found in the crystal structure is consistent with experiments in solution. It shows that thumbs and fingertips, and, by extension, the bound heme groups, are shielded from competing heme-binding proteins from the host. This may also facilitate heme transport to HmuR for internalization. HmuY, both in its apo- and in its heme-bound forms, is resistant to proteolytic digestion by trypsin and the major secreted proteases of P. gingivalis, gingipains K and R. It is also stable against thermal and chemical denaturation. In conclusion, these studies reveal novel molecular properties of HmuY that are consistent with its role as a putative virulence factor during bacterial infection.

  20. A New Star-shaped Carbazole Derivative with Polyhedral Oligomeric Silsesquioxane Core: Crystal Structure and Unique Photoluminescence Property.

    Science.gov (United States)

    Xu, Zixuan; Yu, Tianzhi; Zhao, Yuling; Zhang, Hui; Zhao, Guoyun; Li, Jianfeng; Chai, Lanqin

    2016-01-01

    A new inorganic–organic hybrid material based on polyhedral oligomeric silsesquioxane (POSS) capped with carbazolyl substituents, octakis[3-(carbazol-9-yl)propyldimethylsiloxy]-silsesquioxane (POSS-8Cz), was successfully synthesized and characterized. The X-ray crystal structure of POSS-8Cz were described. The photophysical properties of POSS-8Cz were investigated by using UV–vis,photoluminescence spectroscopic analysis. The hybrid material exhibits blue emission in the solution and the solid film.The morphology and thermal stablity properties were measured by X-ray diffraction (XRD) and TG-DTA analysis.

  1. Kinetic and structural studies reveal a unique binding mode of sulfite to the nickel center in urease.

    Science.gov (United States)

    Mazzei, Luca; Cianci, Michele; Benini, Stefano; Bertini, Leonardo; Musiani, Francesco; Ciurli, Stefano

    2016-01-01

    Urease is the most efficient enzyme known to date, and catalyzes the hydrolysis of urea using two Ni(II) ions in the active site. Urease is a virulence factor in several human pathogens, while causing severe environmental and agronomic problems. Sporosarcina pasteurii urease has been used extensively in the structural characterization of the enzyme. Sodium sulfite has been widely used as a preservative in urease solutions to prevent oxygen-induced oxidation, but its role as an inhibitor has also been suggested. In the present study, isothermal titration microcalorimetry was used to establish sulfite as a competitive inhibitor for S. pasteurii urease, with an inhibition constant of 0.19mM at pH7. The structure of the urease-sulfite complex, determined at 1.65Å resolution, shows the inhibitor bound to the dinuclear Ni(II) center of urease in a tridentate mode involving bonds between the two Ni(II) ions in the active site and all three oxygen atoms of the inhibitor, supporting the observed competitive inhibition kinetics. This coordination mode of sulfite has never been observed, either in proteins or in small molecule complexes, and could inspire synthetic coordination chemists as well as biochemists to develop urease inhibitors based on this chemical moiety. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. CsAg{sub 5}Te{sub 3}: a new metal-rich telluride with a unique tunnel structure

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Li [Rutgers Univ., Camden, NJ (United States). Dept. of Chem.; Hongyou, Guo [Rutgers Univ., Camden, NJ (United States). Dept. of Chem.; Xiang, Zhang [Michigan State Univ., East Lansing, MI (United States). Dept. of Chemistry; Kanatzidis, M G [Michigan State Univ., East Lansing, MI (United States). Dept. of Chemistry

    1995-02-15

    The synthesis and structure of a new ternary silver telluride, CsAg{sub 5}Te{sub 3}, is described. The compound was prepared from a Cs{sub 2}Te-CaTe-Te flux but it can also be prepared from a direct combination of Cs{sub 2}Te and Ag{sub 2}Te under vacuum at 600 C. The crystal data for CsAg{sub 5}Te{sub 3} at 20 C (Mo K{alpha} radiation) are as follows: a=14.672(2) A and c=4.601(3) A; V=990.5(8) A{sup 3}; Z=4; D{sub calc}=7.075 g cm{sup -3}; space group, P4{sub 2} /mnm (No. 136); 2{theta}{sub max}=50 ; number of independent data collected, 572; number of data observed with I>3{sigma}(I), 267; number of variables, 32; {mu}=218.51 cm{sup -1}; extinction coefficient, 0.585x10{sup -7}; final R=0.040; R{sub w}=0.046; goodness of fit, 1.42. The compound features a new structure type with Cs{sup +}-filled, relatively large tunnels running through the lattice. The material is a semiconductor with a band gap of about 0.65 eV. ((orig.))

  3. Unique cellular structures in the parotid gland of an Old world fruit bat, Pteropus lylei (Lyle's flying fox).

    Science.gov (United States)

    Lanlua, Passara; Sricharoenvej, Sirinush; Niyomchan, Apichaya; Chico, Diane E

    2007-01-01

    Pteropus lylei (Lyle's flying fox), an Old World fruit bat, consumes only ripe fruit, which contains low protein and sodium. The carpophagous diet of P. lylei presents an adaptive challenge for salivary glands to conserve sufficient nutrition for living. Therefore, the parotid glands in both sexes were investigated by using light microscopy and transmission electron microscopy. No structural difference was observed in the parotid glands between sexes. The acinar cell contained dense serous secretory granules, prominent luminal microvilli and intercellular canaliculi. The intercalated duct exhibited simple cuboidal epithelium with no secretory granule. Striated duct consisted of simple columnar epithelium with basal striation, numerous elongated mitochondria, and apical vesicles. In the interlobular duct, simple tall columnar epithelium and apocrine secretion were found. The interlobar and excretory ducts surprisingly contained continuous capillaries that intervened in stratified cuboidal epithelium. In addition, there were several blood vessels around the interlobular, interlobar and excretory ducts. The morphological adaptation of the parotid gland observed in P. lylei enables this species to obtain sufficient nutrients from the preferred consumption of ripe fruit. Serous secretory granule was suitable for digestion of ripe fruit. A well-developed striated duct, continuous capillaries among the epithelial cells of interlobar and excretory ducts, and numerous blood vessels around these ducts enhanced the reabsorption of amino acids and ions. Structural variations in the parotid gland can indicate not only a correlation to diet and survival but also a close relationship of the Old World fruit bat to other kinds of bats.

  4. Unique Optoelectronic Structure and Photoreduction Properties of Sulfur-Doped Lead Chromates Explaining Their Instability in Paintings.

    Science.gov (United States)

    Rahemi, Vanoushe; Sarmadian, Nasrin; Anaf, Willemien; Janssens, Koen; Lamoen, Dirk; Partoens, Bart; De Wael, Karolien

    2017-03-21

    Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artist's material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr 1-x S x O 4 , with 0 ≤ x ≤ 0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO 4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the coprecipitate with lead sulfate (PbCr 1-x S x O 4 ) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that, when the the sulfur(S)-content in chrome yellow increases, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photoactivity is the result. However, the photoactivity relative to the Cr content and, thus, Cr reduction of sulfur-rich PbCr 1-x S x O 4 is found to be much higher compared to the sulfur-poor or nondoped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as a function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its coprecipitates are p-type semiconductors, which explains the observed reduction reaction. Because understanding this phenomenon is

  5. Mechanistic and Structural Insights Into the Unique TetR-Dependent Regulation of a Drug Efflux Pump in Mycobacterium abscessus.

    Science.gov (United States)

    Richard, Matthias; Gutiérrez, Ana Victoria; Viljoen, Albertus J; Ghigo, Eric; Blaise, Mickael; Kremer, Laurent

    2018-01-01

    Mycobacterium abscessus is an emerging human pathogen causing severe pulmonary infections and is refractory to standard antibiotherapy, yet few drug resistance mechanisms have been reported in this organism. Recently, mutations in MAB_4384 leading to up-regulation of the MmpS5/MmpL5 efflux pump were linked to increased resistance to thiacetazone derivatives. Herein, the DNA-binding activity of MAB_4384 was investigated by electrophoretic mobility shift assays using the palindromic sequence IR S5/L5 located upstream of mmpS5/mmpL5 . Introduction of point mutations within IR S5/L5 identified the sequence requirements for optimal binding of the regulator. Moreover, formation of the protein/IR S5/L5 complex was severely impaired for MAB_4384 harboring D14N or F57L substitutions. IR S5/L5 /lacZ reporter fusions in M. abscessus demonstrated increased β-galactosidase activity either in strains lacking a functional MAB_4384 or in cultures treated with the TAC analogs. In addition, X-ray crystallography confirmed a typical TetR homodimeric structure of MAB_4384 and unraveled a putative ligand binding site in which the analogs could be docked. Overall, these results support drug recognition of the MAB_4384 TetR regulator, alleviating its binding to IR S5/L5 and steering up-regulation of MmpS5/MmpL5. This study provides new mechanistic and structural details of TetR-dependent regulatory mechanisms of efflux pumps and drug resistance in mycobacteria.

  6. The crystal structure of Haloferax volcanii proliferating cell nuclear antigen reveals unique surface charge characteristics due to halophilic adaptation

    Directory of Open Access Journals (Sweden)

    Morroll Shaun

    2009-08-01

    Full Text Available Abstract Background The high intracellular salt concentration required to maintain a halophilic lifestyle poses challenges to haloarchaeal proteins that must stay soluble, stable and functional in this extreme environment. Proliferating cell nuclear antigen (PCNA is a fundamental protein involved in maintaining genome integrity, with roles in both DNA replication and repair. To investigate the halophilic adaptation of such a key protein we have crystallised and solved the structure of Haloferax volcanii PCNA (HvPCNA to a resolution of 2.0 Å. Results The overall architecture of HvPCNA is very similar to other known PCNAs, which are highly structurally conserved. Three commonly observed adaptations in halophilic proteins are higher surface acidity, bound ions and increased numbers of intermolecular ion pairs (in oligomeric proteins. HvPCNA possesses the former two adaptations but not the latter, despite functioning as a homotrimer. Strikingly, the positive surface charge considered key to PCNA's role as a sliding clamp is dramatically reduced in the halophilic protein. Instead, bound cations within the solvation shell of HvPCNA may permit sliding along negatively charged DNA by reducing electrostatic repulsion effects. Conclusion The extent to which individual proteins adapt to halophilic conditions varies, presumably due to their diverse characteristics and roles within the cell. The number of ion pairs observed in the HvPCNA monomer-monomer interface was unexpectedly low. This may reflect the fact that the trimer is intrinsically stable over a wide range of salt concentrations and therefore additional modifications for trimer maintenance in high salt conditions are not required. Halophilic proteins frequently bind anions and cations and in HvPCNA cation binding may compensate for the remarkable reduction in positive charge in the pore region, to facilitate functional interactions with DNA. In this way, HvPCNA may harness its environment as

  7. The crystal structure of Haloferax volcanii proliferating cell nuclear antigen reveals unique surface charge characteristics due to halophilic adaptation

    Science.gov (United States)

    Winter, Jody A; Christofi, Panayiotis; Morroll, Shaun; Bunting, Karen A

    2009-01-01

    Background The high intracellular salt concentration required to maintain a halophilic lifestyle poses challenges to haloarchaeal proteins that must stay soluble, stable and functional in this extreme environment. Proliferating cell nuclear antigen (PCNA) is a fundamental protein involved in maintaining genome integrity, with roles in both DNA replication and repair. To investigate the halophilic adaptation of such a key protein we have crystallised and solved the structure of Haloferax volcanii PCNA (HvPCNA) to a resolution of 2.0 Å. Results The overall architecture of HvPCNA is very similar to other known PCNAs, which are highly structurally conserved. Three commonly observed adaptations in halophilic proteins are higher surface acidity, bound ions and increased numbers of intermolecular ion pairs (in oligomeric proteins). HvPCNA possesses the former two adaptations but not the latter, despite functioning as a homotrimer. Strikingly, the positive surface charge considered key to PCNA's role as a sliding clamp is dramatically reduced in the halophilic protein. Instead, bound cations within the solvation shell of HvPCNA may permit sliding along negatively charged DNA by reducing electrostatic repulsion effects. Conclusion The extent to which individual proteins adapt to halophilic conditions varies, presumably due to their diverse characteristics and roles within the cell. The number of ion pairs observed in the HvPCNA monomer-monomer interface was unexpectedly low. This may reflect the fact that the trimer is intrinsically stable over a wide range of salt concentrations and therefore additional modifications for trimer maintenance in high salt conditions are not required. Halophilic proteins frequently bind anions and cations and in HvPCNA cation binding may compensate for the remarkable reduction in positive charge in the pore region, to facilitate functional interactions with DNA. In this way, HvPCNA may harness its environment as opposed to simply surviving in

  8. Quantitative Analysis of Major Factors Affecting Black Carbon Transport and Concentrations in the Unique Atmospheric Structures of Urban Environment

    Science.gov (United States)

    Liang, Marissa Shuang

    Black carbon (BC) from vehicular emission in transportation is a principal component of particulate matters ≤ 2.5 mum (PM2.5). PM2.5 and other diesel emission pollutants (e.g., NOx) are regulated by the Clean Air Act (CAA) according to the National Ambient Air Quality standards (NAAQS). This doctoral dissertation details a study on transport behaviors of black carbon and PM2.5 from transportation routes, their relations with the atmospheric structure of an urban formation, and their relations with the use of biodiesel fuels. The results have implications to near-road risk assessment and to the development of sustainable transportation solutions in urban centers. The first part of study quantified near-roadside black carbon transport as a function of particulate matter (PM) size and composition, as well as microclimatic variables (temperature and wind fields) at the interstate highway I-75 in northern Cincinnati, Ohio. Among variables examined, wind speed and direction significantly affect the roadside transport of black carbon and hence its effective emission factor. Observed non-Gaussian dispersion occurred during low wind and for wind directions at acute angles or upwind to the receptors, mostly occurring in the morning hours. Meandering of air pollutant mass under thermal inversion is likely the driving force. In contrary, Gaussian distribution predominated in daytime of strong downwinds. The roles of urban atmospheric structure, wind fields, and the urban heat island (UHI) effects were further examined on pollutant dispersion and transport. Spatiotemporal variations of traffic flow, atmospheric structure, ambient temperature and PM2.5 concentration data from 14 EPA-certified NAAQS monitoring stations, were analyzed in relation to land-use in the Cincinnati metropolitan area. The results show a decade-long UHI effects with higher interior temperature than that in exurban, and a prominent nocturnal thermal inversion frequent in urban boundary layer. The

  9. Superhard behaviour, low residual stress, and unique structure in diamond-like carbon films by simple bilayer approach

    International Nuclear Information System (INIS)

    Dwivedi, Neeraj; Kumar, Sushil; Malik, Hitendra K.

    2012-01-01

    Simple bilayer approach is proposed for synthesizing hard and superhard diamond-like carbon (DLC) coatings with reduced residual stress. For this, M/DLC bilayer (M = Ti and Cu) structures are grown using hybrid system involving radio frequency (RF)-sputtering and RF-plasma enhanced chemical vapor deposition techniques. Ti/DLC bilayer deposited at negative self bias of 100 V shows superhard behaviour with hardness (H) as 49 GPa. Cu/DLC bilayer grown at self bias of 100 V exhibits hard behaviour with H as 22.8 GPa. The hardness of Ti/DLC (Cu/DLC) bilayer gets changed from superhard (hard) to hard (moderate hard) regime, when the self bias is raised to 300 V. Residual stress in Ti/DLC (Cu/DLC) bilayer is found to be significantly low that varies in the range of 1 GPa-1.65 GPa (0.8 GPa-1.6 GPa). The microstructure and morphology are studied by Raman spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). SEM and AFM pictures reveal the creation of nanostructured features in the deposited bilayers. Raman, SEM, and AFM analyses are correlated with the nano-mechanical properties. Owing to excellent nano-mechanical properties, these bilayers can find their direct industrial applications as hard and protective coatings.

  10. Shared and unique components of human population structure and genome-wide signals of positive selection in South Asia.

    Science.gov (United States)

    Metspalu, Mait; Romero, Irene Gallego; Yunusbayev, Bayazit; Chaubey, Gyaneshwer; Mallick, Chandana Basu; Hudjashov, Georgi; Nelis, Mari; Mägi, Reedik; Metspalu, Ene; Remm, Maido; Pitchappan, Ramasamy; Singh, Lalji; Thangaraj, Kumarasamy; Villems, Richard; Kivisild, Toomas

    2011-12-09

    South Asia harbors one of the highest levels genetic diversity in Eurasia, which could be interpreted as a result of its long-term large effective population size and of admixture during its complex demographic history. In contrast to Pakistani populations, populations of Indian origin have been underrepresented in previous genomic scans of positive selection and population structure. Here we report data for more than 600,000 SNP markers genotyped in 142 samples from 30 ethnic groups in India. Combining our results with other available genome-wide data, we show that Indian populations are characterized by two major ancestry components, one of which is spread at comparable frequency and haplotype diversity in populations of South and West Asia and the Caucasus. The second component is more restricted to South Asia and accounts for more than 50% of the ancestry in Indian populations. Haplotype diversity associated with these South Asian ancestry components is significantly higher than that of the components dominating the West Eurasian ancestry palette. Modeling of the observed haplotype diversities suggests that both Indian ancestry components are older than the purported Indo-Aryan invasion 3,500 YBP. Consistent with the results of pairwise genetic distances among world regions, Indians share more ancestry signals with West than with East Eurasians. However, compared to Pakistani populations, a higher proportion of their genes show regionally specific signals of high haplotype homozygosity. Among such candidates of positive selection in India are MSTN and DOK5, both of which have potential implications in lipid metabolism and the etiology of type 2 diabetes. Copyright © 2011 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  11. 4.0-A resolution cryo-EM structure of the mammalian chaperonin TRiC/CCT reveals its unique subunit arrangement.

    Science.gov (United States)

    Cong, Yao; Baker, Matthew L; Jakana, Joanita; Woolford, David; Miller, Erik J; Reissmann, Stefanie; Kumar, Ramya N; Redding-Johanson, Alyssa M; Batth, Tanveer S; Mukhopadhyay, Aindrila; Ludtke, Steven J; Frydman, Judith; Chiu, Wah

    2010-03-16

    The essential double-ring eukaryotic chaperonin TRiC/CCT (TCP1-ring complex or chaperonin containing TCP1) assists the folding of approximately 5-10% of the cellular proteome. Many TRiC substrates cannot be folded by other chaperonins from prokaryotes or archaea. These unique folding properties are likely linked to TRiC's unique heterooligomeric subunit organization, whereby each ring consists of eight different paralogous subunits in an arrangement that remains uncertain. Using single particle cryo-EM without imposing symmetry, we determined the mammalian TRiC structure at 4.7-A resolution. This revealed the existence of a 2-fold axis between its two rings resulting in two homotypic subunit interactions across the rings. A subsequent 2-fold symmetrized map yielded a 4.0-A resolution structure that evinces the densities of a large fraction of side chains, loops, and insertions. These features permitted unambiguous identification of all eight individual subunits, despite their sequence similarity. Independent biochemical near-neighbor analysis supports our cryo-EM derived TRiC subunit arrangement. We obtained a Calpha backbone model for each subunit from an initial homology model refined against the cryo-EM density. A subsequently optimized atomic model for a subunit showed approximately 95% of the main chain dihedral angles in the allowable regions of the Ramachandran plot. The determination of the TRiC subunit arrangement opens the way to understand its unique function and mechanism. In particular, an unevenly distributed positively charged wall lining the closed folding chamber of TRiC differs strikingly from that of prokaryotic and archaeal chaperonins. These interior surface chemical properties likely play an important role in TRiC's cellular substrate specificity.

  12. Single crystal structure analyses of scheelite-powellite CaW1-xMoxO4 solidsolutions and unique occurrence in Jisyakuyama skarn deposits

    Science.gov (United States)

    Yamashita, K.; Yoshiasa, A.; Miyazaki, H.; Tokuda, M.; Tobase, T.; Isobe, H.; Nishiyama, T.; Sugiyama, K.; Miyawaki, R.

    2017-12-01

    Jisyakuyama skarn deposit, Fukuchi, Fukuoka, Japan, shows a simple occurrenceformed by penetration of hot water into limestone cracks. A unique occurrence of scheelite-powellite CaW1-xMoxO4 minerals is observed in the skarn deposit. Many syntheticexperiments for scheelite-powellite solid solutions have been reported as research onfluorescent materials. In this system it is known that a complete continuous solid solution isformed even at room temperature. In this study, we have carried out the chemical analyses,crystal structural refinements and detail description of occurrence on scheelite-powelliteminerals. We have also attempted synthesis of single crystal of solid solution in a widecomposition range. The chemical compositions were determined by JEOL scanningelectron microscope and EDS, INCA system. We have performed the crystal structurerefinements of the scheelite-powellite CaW1-xMoxO4 solid solutions (x=0.0-1.0) byRIGAKU single-crystal structure analysis system RAPID. The R and S values are around0.0s and 1.03. As the result of structural refinements of natural products and many solidsolutions, we confirm that most large natural single crystals have compositions at bothendmembers, and large solid solution crystals are rare. The lattice constants, interatomicdistances and other crystallographic parameters for the solid solution change uniquely withcomposition and it was confirmed as a continuous solid solution. Single crystals of scheeliteendmember + powellite endmember + solid solution with various compositions form anaggregate in the deposit (Figure 1). Crystal shapes of powellite and scheelite arehypidiomorphic and allotriomorphic, respectively. Many solid solution crystals areaccompanied by scheelite endmember and a compositional gap is observed betweenpowellite and solid-solution crystals. The presence of several penetration solutions withsignificantly different W and Mo contents may be assumed. This research can be expectedto lead to giving restrictive

  13. Enabling cell-cell communication via nanopore formation: structure, function and localization of the unique cell wall amidase AmiC2 of Nostoc punctiforme.

    Science.gov (United States)

    Büttner, Felix M; Faulhaber, Katharina; Forchhammer, Karl; Maldener, Iris; Stehle, Thilo

    2016-04-01

    To orchestrate a complex life style in changing environments, the filamentous cyanobacterium Nostoc punctiforme facilitates communication between neighboring cells through septal junction complexes. This is achieved by nanopores that perforate the peptidoglycan (PGN) layer and traverse the cell septa. The N-acetylmuramoyl-l-alanine amidase AmiC2 (Npun_F1846; EC 3.5.1.28) in N. punctiforme generates arrays of such nanopores in the septal PGN, in contrast to homologous amidases that mediate daughter cell separation after cell division in unicellular bacteria. Nanopore formation is therefore a novel property of AmiC homologs. Immunofluorescence shows that native AmiC2 localizes to the maturing septum. The high-resolution crystal structure (1.12 Å) of its catalytic domain (AmiC2-cat) differs significantly from known structures of cell splitting and PGN recycling amidases. A wide and shallow binding cavity allows easy access of the substrate to the active site, which harbors an essential zinc ion. AmiC2-cat exhibits strong hydrolytic activity in vitro. A single point mutation of a conserved glutamate near the zinc ion results in total loss of activity, whereas zinc removal leads to instability of AmiC2-cat. An inhibitory α-helix, as found in the Escherichia coli AmiC(E. coli) structure, is absent. Taken together, our data provide insight into the cell-biological, biochemical and structural properties of an unusual cell wall lytic enzyme that generates nanopores for cell-cell communication in multicellular cyanobacteria. The novel structural features of the catalytic domain and the unique biological function of AmiC2 hint at mechanisms of action and regulation that are distinct from other amidases. The AmiC2-cat structure has been deposited in the Protein Data Bank under accession number 5EMI. © 2016 Federation of European Biochemical Societies.

  14. Lipid A structural modifications in extreme conditions and identification of unique modifying enzymes to define the Toll-like receptor 4 structure-activity relationship.

    Science.gov (United States)

    Scott, Alison J; Oyler, Benjamin L; Goodlett, David R; Ernst, Robert K

    2017-11-01

    Strategies utilizing Toll-like receptor 4 (TLR4) agonists for treatment of cancer, infectious diseases, and other targets report promising results. Potent TLR4 antagonists are also gaining attention as therapeutic leads. Though some principles for TLR4 modulation by lipid A have been described, a thorough understanding of the structure-activity relationship (SAR) is lacking. Only through a complete definition of lipid A-TLR4 SAR is it possible to predict TLR4 signaling effects of discrete lipid A structures, rendering them more pharmacologically relevant. A limited 'toolbox' of lipid A-modifying enzymes has been defined and is largely composed of enzymes from mesophile human and zoonotic pathogens. Expansion of this 'toolbox' will result from extending the search into lipid A biosynthesis and modification by bacteria living at the extremes. Here, we review the fundamentals of lipid A structure, advances in lipid A uses in TLR4 modulation, and the search for novel lipid A-modifying systems in extremophile bacteria. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. A High-Resolution Crystal Structure of a Psychrohalophilic α-Carbonic Anhydrase from Photobacterium profundum Reveals a Unique Dimer Interface.

    Directory of Open Access Journals (Sweden)

    Vijayakumar Somalinga

    Full Text Available Bacterial α-carbonic anhydrases (α-CA are zinc containing metalloenzymes that catalyze the rapid interconversion of CO2 to bicarbonate and a proton. We report the first crystal structure of a pyschrohalophilic α-CA from a deep-sea bacterium, Photobacterium profundum. Size exclusion chromatography of the purified P. profundum α-CA (PprCA reveals that the protein is a heterogeneous mix of monomers and dimers. Furthermore, an "in-gel" carbonic anhydrase activity assay, also known as protonography, revealed two distinct bands corresponding to monomeric and dimeric forms of PprCA that are catalytically active. The crystal structure of PprCA was determined in its native form and reveals a highly conserved "knot-topology" that is characteristic of α-CA's. Similar to other bacterial α-CA's, PprCA also crystallized as a dimer. Furthermore, dimer interface analysis revealed the presence of a chloride ion (Cl- in the interface which is unique to PprCA and has not been observed in any other α-CA's characterized so far. Molecular dynamics simulation and chloride ion occupancy analysis shows 100% occupancy for the Cl- ion in the dimer interface. Zinc coordinating triple histidine residues, substrate binding hydrophobic patch residues, and the hydrophilic proton wire residues are highly conserved in PprCA and are identical to other well-studied α-CA's.

  16. Cardiac contractility structure-activity relationship and ligand-receptor interactions; the discovery of unique and novel molecular switches in myosuppressin signaling.

    Directory of Open Access Journals (Sweden)

    Megan Leander

    Full Text Available Peptidergic signaling regulates cardiac contractility; thus, identifying molecular switches, ligand-receptor contacts, and antagonists aids in exploring the underlying mechanisms to influence health. Myosuppressin (MS, a decapeptide, diminishes cardiac contractility and gut motility. Myosuppressin binds to G protein-coupled receptor (GPCR proteins. Two Drosophila melanogaster myosuppressin receptors (DrmMS-Rs exist; however, no mechanism underlying MS-R activation is reported. We predicted DrmMS-Rs contained molecular switches that resembled those of Rhodopsin. Additionally, we believed DrmMS-DrmMS-R1 and DrmMS-DrmMS-R2 interactions would reflect our structure-activity relationship (SAR data. We hypothesized agonist- and antagonist-receptor contacts would differ from one another depending on activity. Lastly, we expected our study to apply to other species; we tested this hypothesis in Rhodnius prolixus, the Chagas disease vector. Searching DrmMS-Rs for molecular switches led to the discovery of a unique ionic lock and a novel 3-6 lock, as well as transmission and tyrosine toggle switches. The DrmMS-DrmMS-R1 and DrmMS-DrmMS-R2 contacts suggested tissue-specific signaling existed, which was in line with our SAR data. We identified R. prolixus (RhpMS-R and discovered it, too, contained the unique myosuppressin ionic lock and novel 3-6 lock found in DrmMS-Rs as well as transmission and tyrosine toggle switches. Further, these motifs were present in red flour beetle, common water flea, honey bee, domestic silkworm, and termite MS-Rs. RhpMS and DrmMS decreased R. prolixus cardiac contractility dose dependently with EC50 values of 140 nM and 50 nM. Based on ligand-receptor contacts, we designed RhpMS analogs believed to be an active core and antagonist; testing on heart confirmed these predictions. The active core docking mimicked RhpMS, however, the antagonist did not. Together, these data were consistent with the unique ionic lock, novel 3-6 lock

  17. Unique structure of iC3b resolved at a resolution of 24 Å by 3D-electron microscopy.

    Science.gov (United States)

    Alcorlo, Martin; Martínez-Barricarte, Ruben; Fernández, Francisco J; Rodríguez-Gallego, César; Round, Adam; Vega, M Cristina; Harris, Claire L; de Cordoba, Santiago Rodríguez; Llorca, Oscar

    2011-08-09

    Activation of C3, deposition of C3b on the target surface, and subsequent amplification by formation of a C3-cleaving enzyme (C3-convertase; C3bBb) triggers the effector functions of complement that result in inflammation and cell lysis. Concurrently, surface-bound C3b is proteolyzed to iC3b by factor I and appropriate cofactors. iC3b then interacts with the complement receptors (CR) of the Ig superfamily, CR2 (CD21), CR3 (CD11b/CD18), and CR4 (CD11c/CD18) on leukocytes, down-modulating inflammation, enhancing B cell-mediated immunity, and targeting pathogens for clearance by phagocytosis. Using EM and small-angle X-ray scattering, we now present a medium-resolution structure of iC3b (24 Å). iC3b displays a unique conformation with structural features distinct from any other C3 fragment. The macroglobulin ring in iC3b is similar to that in C3b, whereas the TED (thioester-containing domain) domain and the remnants of the CUB (complement protein subcomponents C1r/C1s, urchin embryonic growth factor and bone morphogenetic protein 1) domain have moved to locations more similar to where they were in native C3. A consequence of this large conformational change is the disruption of the factor B binding site, which renders iC3b unable to assemble a C3-convertase. This structural model also justifies the decreased interaction between iC3b and complement regulators and the recognition of iC3b by the CR of the Ig superfamily, CR2, CR3, and CR4. These data further illustrate the extraordinary conformational versatility of C3 to accommodate a great diversity of functional activities.

  18. Formation of a unique cluster of G-quadruplex structures in the HIV-1 Nef coding region: implications for antiviral activity.

    Directory of Open Access Journals (Sweden)

    Rosalba Perrone

    Full Text Available G-quadruplexes are tetraplex structures of nucleic acids that can form in G-rich sequences. Their presence and functional role have been established in telomeres, oncogene promoters and coding regions of the human chromosome. In particular, they have been proposed to be directly involved in gene regulation at the level of transcription. Because the HIV-1 Nef protein is a fundamental factor for efficient viral replication, infectivity and pathogenesis in vitro and in vivo, we investigated G-quadruplex formation in the HIV-1 nef gene to assess the potential for viral inhibition through G-quadruplex stabilization. A comprehensive computational analysis of the nef coding region of available strains showed the presence of three conserved sequences that were uniquely clustered. Biophysical testing proved that G-quadruplex conformations were efficiently stabilized or induced by G-quadruplex ligands in all three sequences. Upon incubation with a G-quadruplex ligand, Nef expression was reduced in a reporter gene assay and Nef-dependent enhancement of HIV-1 infectivity was significantly repressed in an antiviral assay. These data constitute the first evidence of the possibility to regulate HIV-1 gene expression and infectivity through G-quadruplex targeting and therefore open a new avenue for viral treatment.

  19. Non-Born-Oppenheimer electronic and nuclear densities for a Hooke-Calogero three-particle model: non-uniqueness of density-derived molecular structure.

    Science.gov (United States)

    Ludeña, E V; Echevarría, L; Lopez, X; Ugalde, J M

    2012-02-28

    We consider the calculation of non-Born-Oppenheimer, nBO, one-particle densities for both electrons and nuclei. We show that the nBO one-particle densities evaluated in terms of translationally invariant coordinates are independent of the wavefunction describing the motion of center of mass of the whole system. We show that they depend, however, on an arbitrary reference point from which the positions of the vectors labeling the particles are determined. We examine the effect that this arbitrary choice has on the topology of the one-particle density by selecting the Hooke-Calogero model of a three-body system for which expressions for the one-particle densities can be readily obtained in analytic form. We extend this analysis to the one-particle densities obtained from full Coulomb interaction wavefunctions for three-body systems. We conclude, in view of the fact that there is a close link between the choice of the reference point and the topology of one-particle densities that the molecular structure inferred from the topology of these densities is not unique. We analyze the behavior of one-particle densities for the Hooke-Calogero Born-Oppenheimer, BO, wavefunction and show that topological transitions are also present in this case for a particular mass value of the light particles even though in the BO regime the nuclear masses are infinite. In this vein, we argue that the change in topology caused by variation of the mass ratio between light and heavy particles does not constitute a true indication in the nBO regime of the emergence of molecular structure.

  20. Ligand design for alkali-metal-templated self-assembly of unique high-nuclearity CuII aggregates with diverse coordination cage units: crystal structures and properties.

    Science.gov (United States)

    Du, Miao; Bu, Xian-He; Guo, Ya-Mei; Ribas, Joan

    2004-03-19

    The construction of two unique, high-nuclearity Cu(II) supramolecular aggregates with tetrahedral or octahedral cage units, [(mu(3)-Cl)[Li subset Cu(4)(mu-L(1))(3)](3)](ClO(4))(8)(H(2)O)(4.5) (1) and [[Na(2) subset Cu(12)(mu-L(2))(8)(mu-Cl)(4)](ClO(4))(8)(H(2)O)(10)(H(3)O(+))(2)](infinity) (2) by alkali-metal-templated (Li(+) or Na(+)) self-assembly, was achieved by the use of two newly designed carboxylic-functionalized diazamesocyclic ligands, N,N'-bis(3-propionyloxy)-1,4-diazacycloheptane (H(2)L(1)) or 1,5-diazacyclooctane-N,N'-diacetate acid (H(2)L(2)). Complex 1 crystallizes in the trigonal R3c space group (a = b = 20.866(3), c = 126.26(4) A and Z = 12), and 2 in the triclinic P1 space group (a = 13.632(4), b = 14.754(4), c = 19.517(6) A, alpha = 99.836(6), beta = 95.793(5), gamma = 116.124(5) degrees and Z = 1). By subtle variation of the ligand structures and the alkali-metal templates, different polymeric motifs were obtained: a dodecanuclear architecture 1 consisting of three Cu(4) tetrahedral cage units with a Li(+) template, and a supramolecular chain 2 consisting of two crystallographically nonequivalent octahedral Cu(6) polyhedra with a Na(+) template. The effects of ligand functionality and alkali metal template ions on the self-assembly processes of both coordination supramolecular aggregates, and their magnetic behaviors are discussed in detail.

  1. Fibrinogen-Related Proteins in Tissue Repair: How a Unique Domain with a Common Structure Controls Diverse Aspects of Wound Healing.

    Science.gov (United States)

    Zuliani-Alvarez, Lorena; Midwood, Kim S

    2015-05-01

    Significance: Fibrinogen-related proteins (FRePs) comprise an intriguing collection of extracellular molecules, each containing a conserved fibrinogen-like globe (FBG). This group includes the eponymous fibrinogen as well as the tenascin, angiopoietin, and ficolin families. Many of these proteins are upregulated during tissue repair and exhibit diverse roles during wound healing. Recent Advances: An increasing body of evidence highlights the specific expression of a number of FRePs following tissue injury and infection. Upon induction, each FReP uses its FBG domain to mediate quite distinct effects that contribute to different stages of tissue repair, such as driving coagulation, pathogen detection, inflammation, angiogenesis, and tissue remodeling. Critical Issues: Despite a high degree of homology among FRePs, each contains unique sequences that enable their diversification of function. Comparative analysis of the structure and function of FRePs and precise mapping of regions that interact with a variety of ligands has started to reveal the underlying molecular mechanisms by which these proteins play very different roles using their common domain. Future Directions: Fibrinogen has long been used in the clinic as a synthetic matrix serving as a scaffold or a delivery system to aid tissue repair. Novel therapeutic strategies are now emerging that harness the use of other FRePs to improve wound healing outcomes. As we learn more about the underlying mechanisms by which each FReP contributes to the repair response, specific blockade, or indeed potentiation, of their function offers real potential to enable regulation of distinct processes during pathological wound healing.

  2. Trinuclear Lanthanoid Complexes of 1,3,5-Triamino-1,3,5-trideoxy-cis-inositol with a Unique, Sandwich-Type Cage Structure(1).

    Science.gov (United States)

    Hedinger, Roman; Ghisletta, Michele; Hegetschweiler, Kaspar; Tóth, Eva; Merbach, André E.; Sessoli, Roberta; Gatteschi, Dante; Gramlich, Volker

    1998-12-28

    A variety of trinuclear complexes [M(3)(H(-)(3)L)(2)](3+) [M = Y, La, Eu, Gd, Dy; L = 1,3,5-triamino-1,3,5-trideoxy-cis-inositol (taci) and 1,3,5-trideoxy-1,3,5-tris(dimethylamino)-cis-inositol (tdci)] was prepared as solid materials of the composition M(3)(H(-)(3)L)(2)X(3).pH(2)O.qEtOH (X = Cl, NO(3); 2.5 structures of [La(3)(H(-)(3)taci)(2)(H(2)O)(4)Cl]Cl(2).3H(2)O and [Gd(3)(H(-)(3)taci)(2)(H(2)O)(6)]Cl(3).3H(2)O were elucidated by single-crystal X-ray diffraction studies. The La complex crystallizes in the orthorhombic space group Pbca, a = 17.10(2) Å, b = 16.20(4) Å, c = 20.25(4) Å, Z = 8 for C(12)Cl(3)H(38)La(3)N(6)O(13). The Gd complex crystallizes in the monoclinic space group P2(1)/n, a = 10.294(3) Å, b = 15.494(5) Å, c = 19.994(6) Å, beta = 95.36(2) degrees, Z = 4 for C(12)Cl(3)Gd(3)H(42)N(6)O(15). The two complexes exhibited a unique, sandwich-type cage structure, where the two triply deprotonated taci ligands encapsulate an equilateral triangle of the three metal centers. The metal cations are coordinated to the equatorial, terminal amino groups and are bridged by the axial &mgr;(2)-alkoxo groups. The coordination spheres are completed by additional peripheral ligands such as H(2)O or Cl(-) counterions. The coordination number of the metal cations is 8. Magnetic susceptibility measurements of the Gd complex revealed very weak antiferromagnetic coupling interactions between the three Gd centers. Complex formation and species distribution in aqueous solution was investigated by potentiometry and pD-dependent NMR spectroscopy. An exclusive formation of the [Eu(3)(H(-)(3)taci)(2)](3+) unit in solution was found in the range 7

  3. Unique features of the structure and interactions of mycobacterial uracil-DNA glycosylase: structure of a complex of the Mycobacterium tuberculosis enzyme in comparison with those from other sources.

    Science.gov (United States)

    Kaushal, Prem Singh; Talawar, Ramappa K; Krishna, P D V; Varshney, Umesh; Vijayan, M

    2008-05-01

    Uracil-DNA glycosylase (UNG), a repair enzyme involved in the excision of uracil from DNA, from mycobacteria differs from UNGs from other sources, particularly in the sequence in the catalytically important loops. The structure of the enzyme from Mycobacterium tuberculosis (MtUng) in complex with a proteinaceous inhibitor (Ugi) has been determined by X-ray analysis of a crystal containing seven crystallographically independent copies of the complex. This structure provides the first geometric characterization of a mycobacterial UNG. A comparison of the structure with those of other UNG proteins of known structure shows that a central core region of the molecule is relatively invariant in structure and sequence, while the N- and C-terminal tails exhibit high variability. The tails are probably important in folding and stability. The mycobacterial enzyme exhibits differences in UNG-Ugi interactions compared with those involving UNG from other sources. The MtUng-DNA complex modelled on the basis of the known structure of the complex involving the human enzyme indicates a domain closure in the enzyme when binding to DNA. The binding involves a larger burial of surface area than is observed in binding by human UNG. The DNA-binding site of MtUng is characterized by the presence of a higher proportion of arginyl residues than is found in the binding site of any other UNG of known structure. In addition to the electrostatic effects produced by the arginyl residues, the hydrogen bonds in which they are involved compensate for the loss of some interactions arising from changes in amino-acid residues, particularly in the catalytic loops. The results arising from the present investigation represent unique features of the structure and interaction of mycobacterial Ungs.

  4. Unique Path Partitions

    DEFF Research Database (Denmark)

    Bessenrodt, Christine; Olsson, Jørn Børling; Sellers, James A.

    2013-01-01

    We give a complete classification of the unique path partitions and study congruence properties of the function which enumerates such partitions.......We give a complete classification of the unique path partitions and study congruence properties of the function which enumerates such partitions....

  5. Uniqueness in time measurement

    International Nuclear Information System (INIS)

    Lorenzen, P.

    1981-01-01

    According to P. Janich a clock is defined as an apparatus in which a point ( hand ) is moving uniformly on a straight line ( path ). For the definition of uniformly first the scaling (as a constant ratio of velocities) is defined without clocks. Thereafter the uniqueness of the time measurement can be proved using the prove of scaling of all clocks. But the uniqueness can be defined without scaling, as it is pointed out here. (orig.) [de

  6. A unique distortion in K{sub 1/3}Ba{sub 2/3}AgTe{sub 2}: X-ray diffraction determination and electronic band structure analysis of its incommensurately modulated structure

    Energy Technology Data Exchange (ETDEWEB)

    Gourdon, O; Hanko, J; Boucher, F; Petricek, V; Whangbo, M H; Kanatzidis, M G; Evain, M

    2000-04-03

    The incommensurately modulated structure of a square Te-net, namely that of K{sub 1/3}Ba{sub 2/3}AgTe{sub 2}, is determined from single-crystal X-ray diffraction data within a (3+1)D higher dimension formalism. The phase is shown to crystallize in the monoclinic symmetry, P2{sub 1}({alpha}0{gamma}) superspace group with the following lattice parameters: a = 4.6441(10) {angstrom}, b = 4.6292(12) {angstrom}, c = 23.765(9) {angstrom}, and {beta} = 101.28(2){degree} with q = 0.3248(6)a* {minus}0.07(8)c*, that is, in a symmetry different from that reported for the average structure (tetragonal) or that assumed from electron diffraction measurements (orthorhombic). After the introduction of a crenel function for the Te displacive description, the refinement converged to a residual factor R = 0.033 for 2583 observed reflections and 115 parameters (R = 0.024 and 0.101 for 1925 main reflections and 658 first-order satellites, respectively). The [Ag{sub 2}-Te{sub 2}] and the Ba/K layers are found to be only weakly modulated. The modulation of the square Te-net is, however, both substantial and unique. Namely, it results in two different units: a V-shaped Te{sub 3} trimer and a W-shaped Te{sub 5} pentamer. To examine both unit types, which are segregated in domains that aperiodically alternate within the Te layers, first principles electronic band structure calculations were carried out for three model commensurate structures using the tight-binding linear-muffin-tin-orbital method (LMTO). The calculations show that the distorted structures of V-pattern (model 2) and W-pattern (model 3) are more stable than the average structure (model 1) and that the V-pattern distortion provides a slightly larger stabilization than does the W-pattern distortion. The Fermi surface calculated for the average structure shows nesting vectors that are consistent with the occurrence of the V- and W-pattern distortions in the Te layers. However, these vectors do not predict the observed modulation

  7. Determination of g-tensors of low-symmetry Nd{sup 3+} centers in LiNbO{sub 3} by rectification of angular dependence of electron paramagnetic resonance spectra

    Energy Technology Data Exchange (ETDEWEB)

    Grachev, V., E-mail: grachev@physics.montana.edu; Malovichko, G. [Physics Department, Montana State University, Bozeman, Montana 59717 (United States); Munro, M. [Quantel Laser, Bozeman, Montana 59715 (United States); Kokanyan, E. [Institute of Physical Researches, Ashtarak (Armenia)

    2015-07-28

    Two procedures for facilitation of line tracing and deciphering of complicated spectra of electron paramagnetic resonance (EPR) were developed: a correction of microwave frequencies for every orientation of external magnetic field on the base of known values of g-tensor components for a reference paramagnetic center and followed rectification of measured angular dependences using plots of effective deviation of g{sup 2}-factors of observed lines from effective g{sup 2}-factors of the reference center versus angles or squared cosines of angles describing magnetic field orientations. Their application to EPR spectra of nearly stoichiometric lithium niobate crystals doped with neodymium allowed identifying two axial and six different low-symmetry Nd{sup 3+} centers, to determine all components of their g-tensors, and to propose common divacancy models for a whole family of Nd{sup 3+} centers.

  8. Structure of the first representative of Pfam family PF04016 (DUF364) reveals enolase and Rossmann-like folds that combine to form a unique active site with a possible role in heavy-metal chelation

    International Nuclear Information System (INIS)

    Miller, Mitchell D.; Aravind, L.; Bakolitsa, Constantina; Rife, Christopher L.; Carlton, Dennis; Abdubek, Polat; Astakhova, Tamara; Axelrod, Herbert L.; Chiu, Hsiu-Ju; Clayton, Thomas; Deller, Marc C.; Duan, Lian; Feuerhelm, Julie; Grant, Joanna C.; Han, Gye Won; Jaroszewski, Lukasz; Jin, Kevin K.; Klock, Heath E.; Knuth, Mark W.; Kozbial, Piotr; Krishna, S. Sri; Kumar, Abhinav; Marciano, David; McMullan, Daniel; Morse, Andrew T.; Nigoghossian, Edward; Okach, Linda; Reyes, Ron; Bedem, Henry van den; Weekes, Dana; Xu, Qingping; Hodgson, Keith O.; Wooley, John; Elsliger, Marc-André; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A.

    2010-01-01

    The crystal structure of the first representative of DUF364 family reveals a combination of enolase N-terminal-like and C-terminal Rossmann-like folds. Analysis of the interdomain cleft combined with sequence and genome context conservation among homologs, suggests a unique catalytic site likely involved in the synthesis of a flavin or pterin derivative. The crystal structure of Dhaf4260 from Desulfitobacterium hafniense DCB-2 was determined by single-wavelength anomalous diffraction (SAD) to a resolution of 2.01 Å using the semi-automated high-throughput pipeline of the Joint Center for Structural Genomics (JCSG) as part of the NIGMS Protein Structure Initiative (PSI). This protein structure is the first representative of the PF04016 (DUF364) Pfam family and reveals a novel combination of two well known domains (an enolase N-terminal-like fold followed by a Rossmann-like domain). Structural and bioinformatic analyses reveal partial similarities to Rossmann-like methyltransferases, with residues from the enolase-like fold combining to form a unique active site that is likely to be involved in the condensation or hydrolysis of molecules implicated in the synthesis of flavins, pterins or other siderophores. The genome context of Dhaf4260 and homologs additionally supports a role in heavy-metal chelation

  9. Structures of two cell wall-associated polysaccharides of a Streptococcus mitis biovar 1 strain. A unique teichoic acid-like polysaccharide and the group O antigen which is a C-polysaccharide in common with pneumococci

    DEFF Research Database (Denmark)

    Bergström, N; Jansson, P.-E.; Kilian, Mogens

    2000-01-01

    The cell wall of Streptococcus mitis biovar 1 strain SK137 contains the C-polysaccharide known as the common antigen of a closely related species Streptococcus pneumoniae, and a teichoic acid-like polysaccharide with a unique structure. The two polysaccharides are different entities and could...... be partially separated by gel chromatography. The structures of the two polysaccharides were determined by chemical methods and by NMR spectroscopy. The teichoic acid-like polymer has a heptasaccharide phosphate repeating unit with the following structure: The structure neither contains ribitol nor glycerol...... phosphate as classical teichoic acids do, thus we have used the expression teichoic acid-like for this polysaccharide. The following structure of the C-polysaccharide repeating unit was established: where AAT is 2-acetamido-4-amino-2,4, 6-trideoxy-D-galactose. It has a carbohydrate backbone identical...

  10. Lattices with unique complements

    CERN Document Server

    Saliĭ, V N

    1988-01-01

    The class of uniquely complemented lattices properly contains all Boolean lattices. However, no explicit example of a non-Boolean lattice of this class has been found. In addition, the question of whether this class contains any complete non-Boolean lattices remains unanswered. This book focuses on these classical problems of lattice theory and the various attempts to solve them. Requiring no specialized knowledge, the book is directed at researchers and students interested in general algebra and mathematical logic.

  11. Structural and functional analysis of a microbial mat ecosystem from a unique permanent hypersaline inland lake: ‘La Salada de Chiprana’ (NE Spain)

    DEFF Research Database (Denmark)

    Jonkers, Henk M.; Ludwig, Rebecca; De Wit, Rutger

    2003-01-01

    The benthic microbial mat community of the only permanent hypersaline natural inland lake of Western Europe, ‘La Salada de Chiprana’, northeastern Spain, was structurally and functionally analyzed. The ionic composition of the lake water is characterized by high concentrations of magnesium...

  12. Structure of Stenotrophomonas maltophilia FeoA complexed with zinc: a unique prokaryotic SH3-domain protein that possibly acts as a bacterial ferrous iron-transport activating factor

    International Nuclear Information System (INIS)

    Su, Yi-Che; Chin, Ko-Hsin; Hung, Hui-Chih; Shen, Gwan-Han; Wang, Andrew H.-J.; Chou, Shan-Ho

    2010-01-01

    The crystal structure of FeoA from Stenotrophomonas maltophilia has been determined to a resolution of 1.7 Å using an Se single-wavelength anomalous dispersion (Se-SAD) approach and revealed a unique dimer cross-linked by two zinc ions and six chloride ions. Iron is vital to the majority of prokaryotes, with ferrous iron believed to be the preferred form for iron uptake owing to its much better solubility. The major route for bacterial ferrous iron uptake is found to be via an Feo (ferrous iron-transport) system comprising the three proteins FeoA, FeoB and FeoC. Although the structure and function of FeoB have received much attention recently, the roles played by FeoA and FeoC have been little investigated to date. Here, the tertiary structure of FeoA from Stenotrophomonas maltophilia (Sm), a vital opportunistic pathogen in immunodepressed hosts, is reported. The crystal structure of SmFeoA has been determined to a resolution of 1.7 Å using an Se single-wavelength anomalous dispersion (Se-SAD) approach. Although SmFeoA bears low sequence identity to eukaryotic proteins, its structure is found to adopt a eukaryotic SH3-domain-like fold. It also bears weak similarity to the C-terminal SH3 domain of bacterial DtxR (diphtheria toxin regulator), with some unique characteristics. Intriguingly, SmFeoA is found to adopt a unique dimer cross-linked by two zinc ions and six anions (chloride ions). Since FeoB has been found to contain a G-protein-like domain with low GTPase activity, FeoA may interact with FeoB through the SH3–G-protein domain interaction to act as a ferrous iron-transport activating factor

  13. The Uniqueness of Milton Friedman

    OpenAIRE

    J. Daniel Hammond

    2013-01-01

    That there is no Milton Friedman today is not a mystery; the mystery is how Milton Friedman could have been. The facts of Friedman’s biography make him unique among twentieth-century public figures. He had extensive knowledge and expertise in mathematics and statistics. Yet he became a critic of ‘formal’ theory, exemplified by mathematical economics, that failed to engage with real-world facts and data, and of econometric modeling that presumed more knowledge of economic structure than Friedm...

  14. Unique Features of Halophilic Proteins.

    Science.gov (United States)

    Arakawa, Tsutomu; Yamaguchi, Rui; Tokunaga, Hiroko; Tokunaga, Masao

    2017-01-01

    Proteins from moderate and extreme halophiles have unique characteristics. They are highly acidic and hydrophilic, similar to intrinsically disordered proteins. These characteristics make the halophilic proteins soluble in water and fold reversibly. In addition to reversible folding, the rate of refolding of halophilic proteins from denatured structure is generally slow, often taking several days, for example, for extremely halophilic proteins. This slow folding rate makes the halophilic proteins a novel model system for folding mechanism analysis. High solubility and reversible folding also make the halophilic proteins excellent fusion partners for soluble expression of recombinant proteins.

  15. Les structures secondaires dans l'ARN : une étude par mesure de forces sur molécules uniques

    OpenAIRE

    Bercy , Mathilde

    2015-01-01

    Traditionally, RNA has been considered as a mere intermediate between DNA, keeper of the genetic information, and proteins, which assume cells self-sustenance. With the discoveries of the transfert RNA in the 70s, and of the ribozymes in the 80s, RNA took on both roles: it can store information in its linear sequence, and tridimensional structuration enables catalytic functions. Since then, numerous roles devoted to RNA have been discovered, particularly for gene expression regulation. Most o...

  16. An integrated health and social care organisation in Sweden: creation and structure of a unique local public health and social care system.

    Science.gov (United States)

    Øvretveit, John; Hansson, Johan; Brommels, Mats

    2010-10-01

    Research and citizens have noted failures in coordinating health and social services and professionals, and the need to address this issue to realize benefits from increasing specialisation. Different methods have been proposed and one has been structural integration of separate services within one organisation. This paper reports an empirical longitudinal study of the development of an integrated health and social care organisation in Sweden combining service provision, purchasing and political governance for a defined population. The study found a combination of influences contributed to the development of this new organisation. The initial structural macro-integration facilitated, but did not of itself result in better clinical care coordination. Other actions were needed to modify the specialised systems and cultures which the organisation inherited. The study design was not able to establish with any degree of certainty whether better patient and cost outcomes resulted, but it did find structural and process changes which make improved outcomes likely. The study concludes that coordinated actions at different levels and of different types were needed to achieve care coordination for patients and that a phased approach was necessary where management capacity and outside expertise are limited. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  17. Crystal structure of Lymnaea stagnalis AChBP complexed with the potent nAChR antagonist DHβE suggests a unique mode of antagonism.

    Directory of Open Access Journals (Sweden)

    Azadeh Shahsavar

    Full Text Available Nicotinic acetylcholine receptors (nAChRs are pentameric ligand-gated ion channels that belong to the Cys-loop receptor superfamily. These receptors are allosteric proteins that exist in different conformational states, including resting (closed, activated (open, and desensitized (closed states. The acetylcholine binding protein (AChBP is a structural homologue of the extracellular ligand-binding domain of nAChRs. In previous studies, the degree of the C-loop radial extension of AChBP has been assigned to different conformational states of nAChRs. It has been suggested that a closed C-loop is preferred for the active conformation of nAChRs in complex with agonists whereas an open C-loop reflects an antagonist-bound (closed state. In this work, we have determined the crystal structure of AChBP from the water snail Lymnaea stagnalis (Ls in complex with dihydro-β-erythroidine (DHβE, which is a potent competitive antagonist of nAChRs. The structure reveals that binding of DHβE to AChBP imposes closure of the C-loop as agonists, but also a shift perpendicular to previously observed C-loop movements. These observations suggest that DHβE may antagonize the receptor via a different mechanism compared to prototypical antagonists and toxins.

  18. Materials by design--exploiting the unique properties of pulsed laser deposition for the synthesis of novel hard materials and structures

    International Nuclear Information System (INIS)

    Willmott, P.R.; Spillmann, H.

    2002-01-01

    Novel multilayer thin film structures with an (A-B-C-B) four-sublayer periodicity were synthesized using pulsed reactive crossed-beam laser ablation. The layers were based on transition metal carbonitrides in which one sublayer (A=TiC x N 1-x ) was optimized for its high hardness, another (C=ZrC x N 1-x ) for its low frictional properties, and a third (B=VC x N 1-x ) which acted as a barrier to dislocation propagation. Control of growth and stoichiometry was facilitated by using thermally stable gases as sources for the carbon and nitrogen which were activated by collisions with the ablation plasma. It was discovered that the ablation yields of Ti, V, and Zr were almost identical, so that the sublayer thickness was directly proportional to the number of ablated shots per sublayer metal. The four-sublayer structures were harder (H-bar=35 GPa) than corresponding bilayer structures (H-bar=30 GPa) in which the VC x N 1-x sublayers were missing. Further improvements are expected by optimizing the sublayer ratios and the absolute period thickness

  19. Is Life Unique?

    Science.gov (United States)

    Abel, David L.

    2011-01-01

    Is life physicochemically unique? No. Is life unique? Yes. Life manifests innumerable formalisms that cannot be generated or explained by physicodynamics alone. Life pursues thousands of biofunctional goals, not the least of which is staying alive. Neither physicodynamics, nor evolution, pursue goals. Life is largely directed by linear digital programming and by the Prescriptive Information (PI) instantiated particularly into physicodynamically indeterminate nucleotide sequencing. Epigenomic controls only compound the sophistication of these formalisms. Life employs representationalism through the use of symbol systems. Life manifests autonomy, homeostasis far from equilibrium in the harshest of environments, positive and negative feedback mechanisms, prevention and correction of its own errors, and organization of its components into Sustained Functional Systems (SFS). Chance and necessity—heat agitation and the cause-and-effect determinism of nature’s orderliness—cannot spawn formalisms such as mathematics, language, symbol systems, coding, decoding, logic, organization (not to be confused with mere self-ordering), integration of circuits, computational success, and the pursuit of functionality. All of these characteristics of life are formal, not physical. PMID:25382119

  20. Crystal Structure of Perakine Reductase, Founding Member of a Novel Aldo-Keto Reductase (AKR) Subfamily That Undergoes Unique Conformational Changes during NADPH Binding*

    Science.gov (United States)

    Sun, Lianli; Chen, Yixin; Rajendran, Chitra; Mueller, Uwe; Panjikar, Santosh; Wang, Meitian; Mindnich, Rebekka; Rosenthal, Cindy; Penning, Trevor M.; Stöckigt, Joachim

    2012-01-01

    Perakine reductase (PR) catalyzes the NADPH-dependent reduction of the aldehyde perakine to yield the alcohol raucaffrinoline in the biosynthetic pathway of ajmaline in Rauvolfia, a key step in indole alkaloid biosynthesis. Sequence alignment shows that PR is the founder of the new AKR13D subfamily and is designated AKR13D1. The x-ray structure of methylated His6-PR was solved to 2.31 Å. However, the active site of PR was blocked by the connected parts of the neighbor symmetric molecule in the crystal. To break the interactions and obtain the enzyme-ligand complexes, the A213W mutant was generated. The atomic structure of His6-PR-A213W complex with NADPH was determined at 1.77 Å. Overall, PR folds in an unusual α8/β6 barrel that has not been observed in any other AKR protein to date. NADPH binds in an extended pocket, but the nicotinamide riboside moiety is disordered. Upon NADPH binding, dramatic conformational changes and movements were observed: two additional β-strands in the C terminus become ordered to form one α-helix, and a movement of up to 24 Å occurs. This conformational change creates a large space that allows the binding of substrates of variable size for PR and enhances the enzyme activity; as a result cooperative kinetics are observed as NADPH is varied. As the founding member of the new AKR13D subfamily, PR also provides a structural template and model of cofactor binding for the AKR13 family. PMID:22334702

  1. Clones or clans: the genetic structure of a deep-sea sponge, Aphrocallistes vastus, in unique sponge reefs of British Columbia, Canada.

    Science.gov (United States)

    Brown, Rachel R; Davis, Corey S; Leys, Sally P

    2017-02-01

    Understanding patterns of reproduction, dispersal and recruitment in deep-sea communities is increasingly important with the need to manage resource extraction and conserve species diversity. Glass sponges are usually found in deep water (>1000 m) worldwide but form kilometre-long reefs on the continental shelf of British Columbia and Alaska that are under threat from trawling and resource exploration. Due to their deep-water habitat, larvae have not yet been found and the level of genetic connectivity between reefs and nonreef communities is unknown. The genetic structure of Aphrocallistes vastus, the primary reef-building species in the Strait of Georgia (SoG) British Columbia, was studied using single nucleotide polymorphisms (SNPs). Pairwise comparisons of multilocus genotypes were used to assess whether sexual reproduction is common. Structure was examined 1) between individuals in reefs, 2) between reefs and 3) between sites in and outside the SoG. Sixty-seven SNPs were genotyped in 91 samples from areas in and around the SoG, including four sponge reefs and nearby nonreef sites. The results show that sponge reefs are formed through sexual reproduction. Within a reef and across the SoG basin, the genetic distance between individuals does not vary with geographic distance (r = -0.005 to 0.014), but populations within the SoG basin are genetically distinct from populations in Barkley Sound, on the west coast of Vancouver Island. Population structure was seen across all sample sites (global F ST  = 0.248), especially between SoG and non-SoG locations (average pairwise F ST  = 0.251). Our results suggest that genetic mixing occurs across sponge reefs via larvae that disperse widely. © 2016 John Wiley & Sons Ltd.

  2. Membrane-Active Epithelial Keratin 6A Fragments (KAMPs) Are Unique Human Antimicrobial Peptides with a Non-αβ Structure

    Science.gov (United States)

    Lee, Judy T. Y.; Wang, Guangshun; Tam, Yu Tong; Tam, Connie

    2016-01-01

    Antibiotic resistance is a pressing global health problem that threatens millions of lives each year. Natural antimicrobial peptides and their synthetic derivatives, including peptoids and peptidomimetics, are promising candidates as novel antibiotics. Recently, the C-terminal glycine-rich fragments of human epithelial keratin 6A were found to have bactericidal and cytoprotective activities. Here, we used an improved 2-dimensional NMR method coupled with a new protocol for structural refinement by low temperature simulated annealing to characterize the solution structure of these kerain-derived antimicrobial peptides (KAMPs). Two specific KAMPs in complex with membrane mimicking sodium dodecyl sulfate (SDS) micelles displayed amphipathic conformations with only local bends and turns, and a central 10-residue glycine-rich hydrophobic strip that is central to bactericidal activity. To our knowledge, this is the first report of non-αβ structure for human antimicrobial peptides. Direct observation of Staphylococcus aureus and Pseudomonas aeruginosa by scanning and transmission electron microscopy showed that KAMPs deformed bacterial cell envelopes and induced pore formation. Notably, in competitive binding experiments, KAMPs demonstrated binding affinities to LPS and LTA that did not correlate with their bactericidal activities, suggesting peptide-LPS and peptide-LTA interactions are less important in their mechanisms of action. Moreover, immunoprecipitation of KAMPs-bacterial factor complexes indicated that membrane surface lipoprotein SlyB and intracellular machineries NQR sodium pump and ribosomes are potential molecular targets for the peptides. Results of this study improve our understanding of the bactericidal function of epithelial cytokeratin fragments, and highlight an unexplored class of human antimicrobial peptides, which may serve as non-αβ peptide scaffolds for the design of novel peptide-based antibiotics. PMID:27891122

  3. Membrane-Active Epithelial Keratin 6A Fragments (KAMPs Are Unique Human Antimicrobial Peptides with a Non-αβ Structure

    Directory of Open Access Journals (Sweden)

    Judy Tsz Ying Lee

    2016-11-01

    Full Text Available Antibiotic resistance is a pressing global health problem that threatens millions of lives each year. Natural antimicrobial peptides and their synthetic derivatives, including peptoids and peptidomimetics, are promising candidates as novel antibiotics. Recently, the C-terminal glycine-rich fragments of human epithelial keratin 6A were found to have bactericidal and cytoprotective activities. Here, we used an improved 2-dimensional NMR method coupled with a new protocol for structural refinement by low temperature simulated annealing to characterize the solution structure of these kerain-derived antimicrobial peptides (KAMPs. Two specific KAMPs in complex with membrane mimicking sodium dodecyl sulfate (SDS micelles displayed amphipathic conformations with only local bends and turns, and a central 10-residue glycine-rich hydrophobic strip that is central to bactericidal activity. To our knowledge, this is the first report of non-αβ structure for human antimicrobial peptides. Direct observation of Staphylococcus aureus and Pseudomonas aeruginosa by scanning and transmission electron microscopy showed that KAMPs deformed bacterial cell envelopes and induced pore formation. Notably, in competitive binding experiments, KAMPs demonstrated binding affinities to LPS and LTA that did not correlate with their bactericidal activities, suggesting peptide-LPS and peptide-LTA interactions are less important in their mechanisms of action. Moreover, immunoprecipitation of KAMPs-bacterial factor complexes indicated that membrane surface lipoprotein SlyB and intracellular machineries NQR sodium pump and ribosomes are potential molecular targets for the peptides. Results of this study improve our understanding of the bactericidal function of epithelial cytokeratin fragments, and highlight an unexplored class of human antimicrobial peptides, which may serve as non-αβ peptide scaffolds for the design of novel peptide-based antibiotics.

  4. Integration of spectral domain optical coherence tomography with microperimetry generates unique datasets for the simultaneous identification of visual function and retinal structure in ophthalmological applications

    Science.gov (United States)

    Koulen, Peter; Gallimore, Gary; Vincent, Ryan D.; Sabates, Nelson R.; Sabates, Felix N.

    2011-06-01

    Conventional perimeters are used routinely in various eye disease states to evaluate the central visual field and to quantitatively map sensitivity. However, standard automated perimetry proves difficult for retina and specifically macular disease due to the need for central and steady fixation. Advances in instrumentation have led to microperimetry, which incorporates eye tracking for placement of macular sensitivity values onto an image of the macular fundus thus enabling a precise functional and anatomical mapping of the central visual field. Functional sensitivity of the retina can be compared with the observed structural parameters that are acquired with high-resolution spectral domain optical coherence tomography and by integration of scanning laser ophthalmoscope-driven imaging. Findings of the present study generate a basis for age-matched comparison of sensitivity values in patients with macular pathology. Microperimetry registered with detailed structural data performed before and after intervention treatments provides valuable information about macular function, disease progression and treatment success. This approach also allows for the detection of disease or treatment related changes in retinal sensitivity when visual acuity is not affected and can drive the decision making process in choosing different treatment regimens and guiding visual rehabilitation. This has immediate relevance for applications in central retinal vein occlusion, central serous choroidopathy, age-related macular degeneration, familial macular dystrophy and several other forms of retina related visual disability.

  5. Unique structure and dynamics of the EphA5 ligand binding domain mediate its binding specificity as revealed by X-ray crystallography, NMR and MD simulations.

    Directory of Open Access Journals (Sweden)

    Xuelu Huan

    Full Text Available The 16 EphA and EphB receptors represent the largest family of receptor tyrosine kinases, and their interactions with 9 ephrin-A and ephrin-B ligands initiate bidirectional signals controlling many physiological and pathological processes. Most interactions occur between receptor and ephrins of the same class, and only EphA4 can bind all A and B ephrins. To understand the structural and dynamic principles that enable Eph receptors to utilize the same jellyroll β-sandwich fold to bind ephrins, the VAPB-MSP domain, peptides and small molecules, we have used crystallography, NMR and molecular dynamics (MD simulations to determine the first structure and dynamics of the EphA5 ligand-binding domain (LBD, which only binds ephrin-A ligands. Unexpectedly, despite being unbound, the high affinity ephrin-binding pocket of EphA5 resembles that of other Eph receptors bound to ephrins, with a helical conformation over the J-K loop and an open pocket. The openness of the pocket is further supported by NMR hydrogen/deuterium exchange data and MD simulations. Additionally, the EphA5 LBD undergoes significant picosecond-nanosecond conformational exchanges over the loops, as revealed by NMR and MD simulations, but lacks global conformational exchanges on the microsecond-millisecond time scale. This is markedly different from the EphA4 LBD, which shares 74% sequence identity and 87% homology. Consequently, the unbound EphA5 LBD appears to comprise an ensemble of open conformations that have only small variations over the loops and appear ready to bind ephrin-A ligands. These findings show how two proteins with high sequence homology and structural similarity are still able to achieve distinctive binding specificities through different dynamics, which may represent a general mechanism whereby the same protein fold can serve for different functions. Our findings also suggest that a promising strategy to design agonists/antagonists with high affinity and selectivity

  6. Synthesis and structure-activity relationship of di-(3, 8-diazabicyclo[3.2.1]octane) diquaternary ammonium salts as unique analgesics.

    Science.gov (United States)

    Liu, Hong; Cheng, Tie-Ming; Zhang, Hong-Mei; Li, Run-Tao

    2003-11-01

    Based on the structure characteristics of the lead compounds, 1, 1' octanedioyl-4, 4'-dimethyl-4, 4'-dibenzyl dipiperazinium dibromide (2) and 3, 8-disubstituted-3, 8-diazabicyclo [3.2.1]octanes (DBO), di-(3, 8-diazabicyclo [3.2.1]octane) diquaternary ammonium salts 3 a-c were designed and synthesized through a highly practical procedure. Target compounds 3 a-c and the hydrochloride salts of their precursors 10 a-c were evaluated for their in vivo analgesic and sedative activities. Interestingly, the introduction of an endoethylenic bridge in the piperazine of lead compound 2 causes loss of the analgesic activity and increases the toxicity dramatically. This result shows that the flexible conformation of piperazine in compound 2 is favorable for interaction with the receptor, and the quaternization of compounds 10 a-c is the main reason for the toxicity increase.

  7. Structural Analysis of β-Fructofuranosidase from Xanthophyllomyces dendrorhous Reveals Unique Features and the Crucial Role of N-Glycosylation in Oligomerization and Activity*

    Science.gov (United States)

    Ramírez-Escudero, Mercedes; Gimeno-Pérez, María; González, Beatriz; Linde, Dolores; Merdzo, Zoran; Fernández-Lobato, María; Sanz-Aparicio, Julia

    2016-01-01

    Xanthophyllomyces dendrorhous β-fructofuranosidase (XdINV)is a highly glycosylated dimeric enzyme that hydrolyzes sucrose and releases fructose from various fructooligosaccharides (FOS) and fructans. It also catalyzes the synthesis of FOS, prebiotics that stimulate the growth of beneficial bacteria in human gut. In contrast to most fructosylating enzymes, XdINV produces neo-FOS, which makes it an interesting biotechnology target. We present here its three-dimensional structure, which shows the expected bimodular arrangement and also a long extension of its C terminus that together with an N-linked glycan mediate the formation of an unusual dimer. The two active sites of the dimer are connected by a long crevice, which might indicate its potential ability to accommodate branched fructans. This arrangement could be representative of a group of GH32 yeast enzymes having the traits observed in XdINV. The inactive D80A mutant was used to obtain complexes with relevant substrates and products, with their crystals structures showing at least four binding subsites at each active site. Moreover, two different positions are observed from subsite +2 depending on the substrate, and thus, a flexible loop (Glu-334–His-343) is essential in binding sucrose and β(2–1)-linked oligosaccharides. Conversely, β(2–6) and neo-type substrates are accommodated mainly by stacking to Trp-105, explaining the production of neokestose and the efficient fructosylating activity of XdINV on α-glucosides. The role of relevant residues has been investigated by mutagenesis and kinetics measurements, and a model for the transfructosylating reaction has been proposed. The plasticity of its active site makes XdINV a valuable and flexible biocatalyst to produce novel bioconjugates. PMID:26823463

  8. The roles of the RIIβ linker and N-terminal cyclic nucleotide-binding domain in determining the unique structures of the type IIβ protein kinase A: a small angle x-ray and neutron scattering study.

    Science.gov (United States)

    Blumenthal, Donald K; Copps, Jeffrey; Smith-Nguyen, Eric V; Zhang, Ping; Heller, William T; Taylor, Susan S

    2014-10-10

    Protein kinase A (PKA) is ubiquitously expressed and is responsible for regulating many important cellular functions in response to changes in intracellular cAMP concentrations. The PKA holoenzyme is a tetramer (R2:C2), with a regulatory subunit homodimer (R2) that binds and inhibits two catalytic (C) subunits; binding of cAMP to the regulatory subunit homodimer causes activation of the catalytic subunits. Four different R subunit isoforms exist in mammalian cells, and these confer different structural features, subcellular localization, and biochemical properties upon the PKA holoenzymes they form. The holoenzyme containing RIIβ is structurally unique in that the type IIβ holoenzyme is much more compact than the free RIIβ homodimer. We have used small angle x-ray scattering and small angle neutron scattering to study the solution structure and subunit organization of a holoenzyme containing an RIIβ C-terminal deletion mutant (RIIβ(1-280)), which is missing the C-terminal cAMP-binding domain to better understand the structural organization of the type IIβ holoenzyme and the RIIβ domains that contribute to stabilizing the holoenzyme conformation. Our results demonstrate that compaction of the type IIβ holoenzyme does not require the C-terminal cAMP-binding domain but rather involves large structural rearrangements within the linker and N-terminal cyclic nucleotide-binding domain of the RIIβ homodimer. The structural rearrangements are significantly greater than seen previously with RIIα and are likely to be important in mediating short range and long range interdomain and intersubunit interactions that uniquely regulate the activity of the type IIβ isoform of PKA. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Extended local similarity analysis (eLSA) reveals unique associations between bacterial community structure and odor emission during pig carcasses decomposition.

    Science.gov (United States)

    Ki, Bo-Min; Ryu, Hee Wook; Cho, Kyung-Suk

    2018-02-22

    Soil burial and composting methods have been widely used for the disposal of pig carcasses. The relationship between bacterial community structure and odor emission was examined using extended local similarity analysis (eLSA) during the degradation of pig carcasses in soil and compost. In soil, Hyphomicrobium, Niastella, Rhodanobacter, Polaromonas, Dokdonella and Mesorhizobium were associated with the emission of sulfur-containing odors such as hydrogen sulfide, methyl mercaptan and dimethyl disulfide. Sphingomonas, Rhodanobacter, Mesorhizobium, Dokdonella, Leucobacter and Truepera were associated with the emission of nitrogen-containing odors including ammonia and trimetylamine. In compost, however, Carnobacteriaceae, Lachnospiaceae and Clostridiales were highly correlated with the emission of sulfur-containing odors, while Rumincoccaceae was associated with the emission of nitrogen-containing odors. The emission of organic acids was closely related to Massilia, Sphaerobacter and Bradyrhizobiaceae in soil, but to Actinobacteria, Sporacetigenium, Micromonosporaceae and Solirubrobacteriales in compost. This study suggests that network analysis using eLSA is a useful strategy for exploring the mechanisms of odor emission during biodegradation of pig carcasses.

  10. Ultraviolet light-induced crosslinking reveals a unique region of local tertiary structure in potato spindle tuber viroid and HeLa 5S RNA

    International Nuclear Information System (INIS)

    Branch, A.D.; Benenfeld, B.J.; Robertson, H.D.

    1985-01-01

    The positions of intramolecular crosslinks induced by irradiation with ultraviolet light were mapped into potato spindle tuber viroid RNA and HeLa 5S rRNA. Crosslinking in each of these molecules occurred at a single major site, which was located by RNA fingerprinting and secondary analysis. Various lines of evidence suggest that these crosslinks identify a previously undescribed element of local tertiary structure common to these two widely divergent RNA molecules: (i) both crosslinks occur in an identical eight-base context, with the sequence 5 GGGAA 3 on one side and the sequence 5 UAC 3 on the other; (ii) both crosslinks connect bases that are not thought to be involved in conventional hydrogen bonding, within regions usually depicted as single-stranded loops flanked by short helical segments; and (iii) both crosslinks connect a purine and a pyrimidine residue, and both may generate the same G-U dimer. Furthermore, it is likely that the crosslinking site is of functional significance because it is located within the most highly conserved region of the viroid sequence and involves bases that are essentially invariant among eukaryotic 5S rRNA molecules

  11. Preparation, structure, and unique redox properties of mono-, bis-, and Tris(diarylmethylene)-1,3,5-trithianes and related compounds

    Science.gov (United States)

    Suzuki; Yoshino; Nishida; Ohkita; Tsuji

    2000-09-08

    A series of 1,3,5-trithianes 1-3 having diarylmethylene units were designed as novel electron donors giving highly colored cationic species upon oxidation. They were prepared along with the dithiane and dithiazine derivatives 4-6 by the reactions of lithiated heterocycles with diaryl ketones followed by dehydration. Voltammetric analyses indicate that a large structural change and/or transannular bonding are induced during their electrochemical oxidation. Mono(diarylmethylene) derivative 1a exhibits electrochromism with vivid change in color from faintly yellow to deep blue with concomitant rotation around the exocyclic bond. Both of the strongly colored salts obtained upon oxidation of 2,4-bis- and 2,4,6-tris(diarylmethylene)-1,3,5-trithianes (2aa and 3) consist of the dications with a 1,2,4-trithiane ring, suggesting the easy skeletal rearrangement of the transannular dications with a trithiabicylo[3.1.0]hexane ring. Upon reduction of these salts were obtained bright yellow 12 and 13, respectively, with high electron-donating properties due to the tetraarylbutadiene-type conjugation, thus giving another class of electrochromic compounds.

  12. A unified picture of the crystal structures of metals

    Science.gov (United States)

    Söderlind, Per; Eriksson, Olle; Johansson, Börje; Wills, J. M.; Boring, A. M.

    1995-04-01

    THE crystal structures of the light actinides have intrigued physicists and chemists for several decades1. Simple metals and transition metals have close-packed, high-symmetry structures, such as body-centred cubic, face-centred cubic and hexagonal close packing. In contrast, the structures of the light actinides are very loosely packed and of low symmetry-tetragonal, orthorhombic and monoclinic. To understand these differences, we have performed total-energy calculations, as a function of volume, for both high-and low-symmetry structures of a simple metal (aluminium), a non-magnetic transition metal (niobium), a ferromagnetic transition metal (iron) and a light actinide (uranium). We find that the crystal structure of all of these metals is determined by the balance between electrostatic (Madelung) interactions, which favour high symmetry, and a Peierls distortion of the crystal lattice, which favours low symmetry. We show that simple metals and transition metals can adopt low-symmetry structures on expansion of the lattice; and we predict that, conversely, the light actinides will undergo transitions to structures of higher symmetry on compression.

  13. A unified picture of the crystal structures of metals

    International Nuclear Information System (INIS)

    Soederlind, P.; Eriksson, O.; Johansson, B.; Wills, J.M.; Boring, A.M.

    1995-01-01

    The crystal structures of the light actinides have intrigued physicists and chemists for several decades. Simple metals and transition metals have close-packed, high-symmetry structures, such as body-centred cubic, face-centred cubic hexagonal close packing. In contrast, the structures of the light actinides are very loosely packed and of low symmetry -tetragonal, orthorhombic and monoclinic. To understand these differences, we have have performed total-energy calculations, as a function of volume, for both high- and low-symmetry structures of a simple metal (aluminium), a non-magnetic transition metal (niobium), a ferromagnetic transition metal (iron) and a light actinide (uranium). We find that the crystal structure of all these metals is determined by the balance between electrostatic (Madelung) interactions, which favour high symmetry, and a Peierls distortion of the crystal lattice, which favours low symmetry. We show that simple metals and transition metals can adopt low-symmetry structures on expansion of the lattice; and we predict that, conversely, the light actinides will undergo transitions to structures of higher symmetry on compression. (author)

  14. Structural and functional analysis of a microbial mat ecosystem from a unique permanent hypersaline inland lake: 'La Salada de Chiprana' (NE Spain).

    Science.gov (United States)

    Jonkers, Henk M; Ludwig, Rebecca; Wit, Rutger; Pringault, Olivier; Muyzer, Gerard; Niemann, Helge; Finke, Niko; Beer, Dirk

    2003-05-01

    The benthic microbial mat community of the only permanent hypersaline natural inland lake of Western Europe, 'La Salada de Chiprana', northeastern Spain, was structurally and functionally analyzed. The ionic composition of the lake water is characterized by high concentrations of magnesium and sulfate, which were respectively 0.35 and 0.5 M at the time of sampling while the total salinity was 78 g l(-1). Community composition was analyzed by microscopy, high-performance liquid chromatography (HPLC) pigment analyses and by studying culturable bacteria from different functional groups. Therefore, denaturing gradient gel electrophoresis (DGGE) was applied on most probable number (MPN) dilution cultures. Microscopy revealed that a thin layer of Chloroflexus-like bacteria overlaid various cyanobacteria-dominated layers each characterized by different morphotypes. DGGE analysis of MPN dilution cultures from distinct mat layers showed that various phylotypes of anoxygenic phototrophic, aerobic heterotrophic, colorless sulfur-, and sulfate-reducing bacteria were present. The mats were furthermore functionally studied and attention was focussed on the relationship between oxygenic primary production and the flow of carbon through the microbial community. Microsensor techniques, porewater and sediment photopigment analysis were applied in order to estimate oxygenic photosynthetic rates, daily dynamics of (in)organic carbon porewater concentration and migration behavior of phototrophs. Chiprana microbial mats produced dissolved organic carbon (DOC) both during the day and night. It was estimated that 14% of the mats gross photosynthetic production and 49% of the mats net photosynthetic production diffused out of the mat in the form of low molecular mass fatty acids, although these compounds made up only 2% of the total DOC pool. The high flux of dissolved fatty acids from the microbial mat to the water column may explain why in this system Chloroflexus-like bacteria

  15. Unique structural features facilitate lizard tail autotomy

    DEFF Research Database (Denmark)

    Sanggaard, Kristian W; Danielsen, Carl Chr; Wogensen, Lise

    2012-01-01

    Autotomy refers to the voluntary shedding of a body part; a renowned example is tail loss among lizards as a response to attempted predation. Although many aspects of lizard tail autotomy have been studied, the detailed morphology and mechanism remains unclear. In the present study, we showed...... that tail shedding by the Tokay gecko (Gekko gecko) and the associated extracellular matrix (ECM) rupture were independent of proteolysis. Instead, lizard caudal autotomy relied on biological adhesion facilitated by surface microstructures. Results based on bio-imaging techniques demonstrated that the tail...

  16. Cancer: Unique to Older Adults

    Science.gov (United States)

    ... A to Z › Cancer › Unique to Older Adults Font size A A A Print Share Glossary Unique ... group with other older people with the same type of cancer. Researchers have found that support groups ...

  17. Deciphering the structure of isomeric oligosaccharides in a complex mixture by tandem mass spectrometry: Photon activation with vacuum ultra-violet brings unique information and enables definitive structure assignment

    Energy Technology Data Exchange (ETDEWEB)

    Ropartz, David, E-mail: David.Ropartz@nantes.inra.fr [INRA, UR1268 Biopolymers Interactions Assemblies, F-44316 Nantes (France); Lemoine, Jérôme [Institut des Sciences Analytiques, UMR 5280, Université Lyon 1-CNRS, Université de Lyon, F-69622 Villeurbanne cedex (France); Giuliani, Alexandre [Synchrotron SOLEIL, L’Orme des Merisiers, F-91190 Gif-sur-Yvette (France); UAR 1008 CEPIA, INRA, F-44316 Nantes (France); Bittebière, Yann [INRA, UR1268 Biopolymers Interactions Assemblies, F-44316 Nantes (France); Enjalbert, Quentin [Institut des Sciences Analytiques, UMR 5280, Université Lyon 1-CNRS, Université de Lyon, F-69622 Villeurbanne cedex (France); Institut Lumière Matière, UMR5306, Université Lyon 1-CNRS, Université de Lyon, F-69622 Villeurbanne cedex (France); Antoine, Rodolphe; Dugourd, Philippe [Institut Lumière Matière, UMR5306, Université Lyon 1-CNRS, Université de Lyon, F-69622 Villeurbanne cedex (France); Ralet, Marie-Christine; Rogniaux, Hélène [INRA, UR1268 Biopolymers Interactions Assemblies, F-44316 Nantes (France)

    2014-01-07

    Graphical abstract: -- Highlights: •A complex mixture of methylated oligogalacturonans was fractionated by IP-RP-UHPLC. •Synchrotron-radiation in VUV range was used as an activation process for tandem MS. •VUV activation brought rich structural information compared to LE-CAD. •Resolution of more than 35 structures, including isomers, was successfully completed. -- Abstract: Carbohydrates have a wide variety of structures whose complexity and heterogeneity challenge the field of analytical chemistry. Tandem mass spectrometry, with its remarkable sensitivity and high information content, provides key advantages to addressing the structural elucidation of polysaccharides. Yet, classical fragmentation by collision-activated dissociation (CAD) in many cases fails to reach a comprehensive structural determination, especially when isomers have to be differentiated. In this work, for the first time, vacuum ultra-violet (VUV) synchrotron radiation is used as the activation process in tandem mass spectrometry of large oligosaccharides. Compared to low energy CAD (LE-CAD), photon activated dissociation brought more straightforward and valuable structural information. The outstanding feature was that complete series of informative ions were produced, with only minor neutral losses. Moreover, systematic fragmentation rules could be drawn thus facilitating the definitive assignments of fragment identities. As a result, most of the structures present in a complex mixture of oligogalacturonans could be comprehensively resolved, including many isomers differing in the position of methyl groups along the galacturonic acid backbone.

  18. Complete nucleotide sequence and genome structure of a Japanese isolate of hibiscus latent Fort Pierce virus, a unique tobamovirus that contains an internal poly(A) region in its 3' end.

    Science.gov (United States)

    Yoshida, Tetsuya; Kitazawa, Yugo; Komatsu, Ken; Neriya, Yutaro; Ishikawa, Kazuya; Fujita, Naoko; Hashimoto, Masayoshi; Maejima, Kensaku; Yamaji, Yasuyuki; Namba, Shigetou

    2014-11-01

    In this study, we detected a Japanese isolate of hibiscus latent Fort Pierce virus (HLFPV-J), a member of the genus Tobamovirus, in a hibiscus plant in Japan and determined the complete sequence and organization of its genome. HLFPV-J has four open reading frames (ORFs), each of which shares more than 98 % nucleotide sequence identity with those of other HLFPV isolates. Moreover, HLFPV-J contains a unique internal poly(A) region of variable length, ranging from 44 to 78 nucleotides, in its 3'-untranslated region (UTR), as is the case with hibiscus latent Singapore virus (HLSV), another hibiscus-infecting tobamovirus. The length of the HLFPV-J genome was 6431 nucleotides, including the shortest internal poly(A) region. The sequence identities of ORFs 1, 2, 3 and 4 of HLFPV-J to other tobamoviruses were 46.6-68.7, 49.9-70.8, 31.0-70.8 and 39.4-70.1 %, respectively, at the nucleotide level and 39.8-75.0, 43.6-77.8, 19.2-70.4 and 31.2-74.2 %, respectively, at the amino acid level. The 5'- and 3'-UTRs of HLFPV-J showed 24.3-58.6 and 13.0-79.8 % identity, respectively, to other tobamoviruses. In particular, when compared to other tobamoviruses, each ORF and UTR of HLFPV-J showed the highest sequence identity to those of HLSV. Phylogenetic analysis showed that HLFPV-J, other HLFPV isolates and HLSV constitute a malvaceous-plant-infecting tobamovirus cluster. These results indicate that the genomic structure of HLFPV-J has unique features similar to those of HLSV. To our knowledge, this is the first report of the complete genome sequence of HLFPV.

  19. Liquid structure and temperature invariance of sound velocity in supercooled Bi melt

    International Nuclear Information System (INIS)

    Emuna, M.; Mayo, M.; Makov, G.; Greenberg, Y.; Caspi, E. N.; Yahel, E.; Beuneu, B.

    2014-01-01

    Structural rearrangement of liquid Bi in the vicinity of the melting point has been proposed due to the unique temperature invariant sound velocity observed above the melting temperature, the low symmetry of Bi in the solid phase and the necessity of overheating to achieve supercooling. The existence of this structural rearrangement is examined by measurements on supercooled Bi. The sound velocity of liquid Bi was measured into the supercooled region to high accuracy and it was found to be invariant over a temperature range of ∼60°, from 35° above the melting point to ∼25° into the supercooled region. The structural origin of this phenomenon was explored by neutron diffraction structural measurements in the supercooled temperature range. These measurements indicate a continuous modification of the short range order in the melt. The structure of the liquid is analyzed within a quasi-crystalline model and is found to evolve continuously, similar to other known liquid pnictide systems. The results are discussed in the context of two competing hypotheses proposed to explain properties of liquid Bi near the melting: (i) liquid bismuth undergoes a structural rearrangement slightly above melting and (ii) liquid Bi exhibits a broad maximum in the sound velocity located incidentally at the melting temperature

  20. Uniquely Strongly Clean Group Rings

    Institute of Scientific and Technical Information of China (English)

    WANG XIU-LAN

    2012-01-01

    A ring R is called clean if every element is the sum of an idempotent and a unit,and R is called uniquely strongly clean (USC for short) if every element is uniquely the sum of an idempotent and a unit that commute.In this article,some conditions on a ring R and a group G such that RG is clean are given.It is also shown that if G is a locally finite group,then the group ring RG is USC if and only if R is USC,and G is a 2-group.The left uniquely exchange group ring,as a middle ring of the uniquely clean ring and the USC ring,does not possess this property,and so does the uniquely exchange group ring.

  1. Using Quantum Confinement to Uniquely Identify Devices

    Science.gov (United States)

    Roberts, J.; Bagci, I. E.; Zawawi, M. A. M.; Sexton, J.; Hulbert, N.; Noori, Y. J.; Young, M. P.; Woodhead, C. S.; Missous, M.; Migliorato, M. A.; Roedig, U.; Young, R. J.

    2015-11-01

    Modern technology unintentionally provides resources that enable the trust of everyday interactions to be undermined. Some authentication schemes address this issue using devices that give a unique output in response to a challenge. These signatures are generated by hard-to-predict physical responses derived from structural characteristics, which lend themselves to two different architectures, known as unique objects (UNOs) and physically unclonable functions (PUFs). The classical design of UNOs and PUFs limits their size and, in some cases, their security. Here we show that quantum confinement lends itself to the provision of unique identities at the nanoscale, by using fluctuations in tunnelling measurements through quantum wells in resonant tunnelling diodes (RTDs). This provides an uncomplicated measurement of identity without conventional resource limitations whilst providing robust security. The confined energy levels are highly sensitive to the specific nanostructure within each RTD, resulting in a distinct tunnelling spectrum for every device, as they contain a unique and unpredictable structure that is presently impossible to clone. This new class of authentication device operates with minimal resources in simple electronic structures above room temperature.

  2. An open-framework bimetallic chalcogenide structure K3Rb3Zn4Sn3Se13 built on a unique [Zn4Sn3Se16]12- cluster: synthesis, crystal structure, ion exchange and optical properties

    International Nuclear Information System (INIS)

    Wu Min; Su Weiping; Jasutkar, Niren; Huang, Xiaoying; Li Jing

    2005-01-01

    Single crystals of K 3 Rb 3 Zn 4 Sn 3 Se 13 were synthesized by solvothermal method. The building block in this structure is a [Zn 4 Sn 3 Se 16 ] 12- cluster which consists of four ZnSe 4 and three SnSe 4 tetrahedra connected through corner-sharing of Se atoms. The 3D network contains intersecting channels running parallel to the crystallographic [2 1 1], [1-1-1] and [12-1] directions. The disordered K + and Rb + cations reside in these channels. Ion exchange of Cs + with disordered Rb + /K + ions in the structure showed a partial replacement of 15.8%. Optical diffuse reflectance experiments were carried out and gave a sharp absorption edge at 2.6 eV

  3. Diabetes: Unique to Older Adults

    Science.gov (United States)

    ... Stroke Urinary Incontinence Related Documents PDF Choosing Wisely: Diabetes Tests and Treatments Download Related Video Join our e-newsletter! Aging & Health A to Z Diabetes Unique to Older Adults This section provides information ...

  4. Building unique surface structure on aramid fibers through a green layer-by-layer self-assembly technique to develop new high performance fibers with greatly improved surface activity, thermal resistance, mechanical properties and UV resistance

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Lifang; Yuan, Li; Guan, Qingbao; Gu, Aijuan, E-mail: ajgu@suda.edu.cn; Liang, Guozheng, E-mail: lgzheng@suda.edu.cn

    2017-07-31

    Highlights: • A green technology is setup to build unique surface structure on aramid fiber (AF). • The method is layer-by-layer self-assembling SiO{sub 2} and layered double hydroxide. • The surface of AF is adjustable by controlling the self-assembly cycle number. • New AF has excellent surface activity, anti-UV, thermal and mechanical properties. • The origin behind attractive performances of new AFs was intensively studied. - Abstract: Combining green preparation and high performance is becoming the direction of sustainable development of materials. How to simultaneously overcome the two bottlenecks (poor surface activity and UV resistance) of aramid fibers (AFs) while improving thermal and mechanical properties through a green process is still an interesting issue with big challenge. Herein, new AFs (BL-AFs) were prepared by alternately self-assembling SiO{sub 2} and MgAlFe layered double hydroxide (LDH) on surfaces of AFs, successively, through a green layer-by-layer (LBL) self-assembly technique without using high temperature and organic solvent. The structures and properties of BL-AFs were systematically studied, which are controllable by adjusting the number of self-assembly cycle. The new fibers with three or more self-assembly cycles have remarkably improved surface activity, thermal resistance, mechanical properties and UV resistance compared with AFs. Typically, with three self-assembly cycles, the initial degradation temperature and char yield of the new fiber (3BL-AF) are as high as 552.9 °C and 81.2%, about 92 °C and 25.2% higher than those of AF, respectively; after 168 h-UV irradiation, the retention of tensile performances of 3BL-AF fiber is as high as 91–95%, about 29–14% higher than that of AF, showing the best overall performances among all modified AFs prepared using a green technique reported so far. The origin behind the attractive performances of BL-AFs is revealed through correlating with structures of original and

  5. The liberal illusion of uniqueness.

    Science.gov (United States)

    Stern, Chadly; West, Tessa V; Schmitt, Peter G

    2014-01-01

    In two studies, we demonstrated that liberals underestimate their similarity to other liberals (i.e., display truly false uniqueness), whereas moderates and conservatives overestimate their similarity to other moderates and conservatives (i.e., display truly false consensus; Studies 1 and 2). We further demonstrated that a fundamental difference between liberals and conservatives in the motivation to feel unique explains this ideological distinction in the accuracy of estimating similarity (Study 2). Implications of the accuracy of consensus estimates for mobilizing liberal and conservative political movements are discussed.

  6. Might "Unique" Factors Be "Common"? On the Possibility of Indeterminate Common-Unique Covariances

    Science.gov (United States)

    Grayson, Dave

    2006-01-01

    The present paper shows that the usual factor analytic structured data dispersion matrix lambda psi lambda' + delta can readily arise from a set of scores y = lambda eta + epsilon, shere the "common" (eta) and "unique" (epsilon) factors have nonzero covariance: gamma = Cov epsilon,eta) is not equal to 0. Implications of this finding are discussed…

  7. Kosovo case: A unique arbitrariness

    Directory of Open Access Journals (Sweden)

    Nakarada Radmila

    2007-01-01

    Full Text Available The end of Cold war, contrary to expectations has brought new conflicts and forms of violence, new divisions and new relativizations of the international legal order. Taking as an example the endeavors to resolve the Kosovo conflict, the author attempts to indicate the broader implications of the international efforts to constitute an independent state on part of the territory of an existing sovereign state. The arguments used to justify the redefinition of the borders of the Serbian state without its consent, the moral, democratic, peace arguments, are reviewed. Particular attention is paid to the argument that Kosovo is a unique case and therefore unique rules should be applied. The author seeks to understand the deeper significance of these efforts, concluding that dismantling the present international legal order is not only a potential danger but a possible aim.

  8. Uniqueness theorems in linear elasticity

    CERN Document Server

    Knops, Robin John

    1971-01-01

    The classical result for uniqueness in elasticity theory is due to Kirchhoff. It states that the standard mixed boundary value problem for a homogeneous isotropic linear elastic material in equilibrium and occupying a bounded three-dimensional region of space possesses at most one solution in the classical sense, provided the Lame and shear moduli, A and J1 respectively, obey the inequalities (3 A + 2 J1) > 0 and J1>O. In linear elastodynamics the analogous result, due to Neumann, is that the initial-mixed boundary value problem possesses at most one solution provided the elastic moduli satisfy the same set of inequalities as in Kirchhoffs theorem. Most standard textbooks on the linear theory of elasticity mention only these two classical criteria for uniqueness and neglect altogether the abundant literature which has appeared since the original publications of Kirchhoff. To remedy this deficiency it seems appropriate to attempt a coherent description ofthe various contributions made to the study of uniquenes...

  9. A unique gesture of sharing

    International Nuclear Information System (INIS)

    Mustafa, T.

    1985-01-01

    The Atoms for Peace program was a unique gesture of sharing on the part of the leading industrialized nation, and has very few parallels in modern history. The author says one of the major advantages of the program for developing nations was the much needed stimulation of their indigenous science and technology efforts and the awakening of their governments to the multifaceted benefits of atomic energy. The author discusses how the program benefited Pakistan in the production of electrical energy and in the application of nuclear techniques in the fields of agriculture and medicine, which help to alleviate hunger and combat disease

  10. Consciousness: a unique way of processing information.

    Science.gov (United States)

    Marchetti, Giorgio

    2018-02-08

    In this article, I argue that consciousness is a unique way of processing information, in that: it produces information, rather than purely transmitting it; the information it produces is meaningful for us; the meaning it has is always individuated. This uniqueness allows us to process information on the basis of our personal needs and ever-changing interactions with the environment, and consequently to act autonomously. Three main basic cognitive processes contribute to realize this unique way of information processing: the self, attention and working memory. The self, which is primarily expressed via the central and peripheral nervous systems, maps our body, the environment, and our relations with the environment. It is the primary means by which the complexity inherent to our composite structure is reduced into the "single voice" of a unique individual. It provides a reference system that (albeit evolving) is sufficiently stable to define the variations that will be used as the raw material for the construction of conscious information. Attention allows for the selection of those variations in the state of the self that are most relevant in the given situation. Attention originates and is deployed from a single locus inside our body, which represents the center of the self, around which all our conscious experiences are organized. Whatever is focused by attention appears in our consciousness as possessing a spatial quality defined by this center and the direction toward which attention is focused. In addition, attention determines two other features of conscious experience: periodicity and phenomenal quality. Self and attention are necessary but not sufficient for conscious information to be produced. Complex forms of conscious experiences, such as the various modes of givenness of conscious experience and the stream of consciousness, need a working memory mechanism to assemble the basic pieces of information selected by attention.

  11. Unique Features of Mobile Commerce

    Institute of Scientific and Technical Information of China (English)

    DING Xiaojun; IIJIMA Junichi; HO Sho

    2004-01-01

    While the market potentials and impacts of web-based e-commerce are still in the ascendant, the advances in wireless technologies and mobile networks have brought about a new business opportunity and research attention, what is termed mobile commerce. Commonly, mobile commerce is considered to be another new application of existing web-based e-commerce onto wireless networks, but as an independent business area, mobile commerce has its own advantages and challenges as opposed to traditional e-commerce applications. This paper focuses on exploring the unique features of mobile commerce as. Compared with traditional e-commerce. Also, there are still some limitations arisen in m-commerce in contrast to web-based e-commerce. Finally, current state of mobile commerce in Japan is presented in brief, with an introduction of several cases involving mobile commerce applications in today 's marketplace.

  12. Unique features of space reactors

    International Nuclear Information System (INIS)

    Buden, D.

    1990-01-01

    This paper reports on space reactors that are designed to meet a unique set of requirements; they must be sufficiently compact to be launched in a rocket to their operational location, operate for many years without maintenance and servicing, operate in extreme environments, and reject heat by radiation to space. To meet these restrictions, operating temperatures are much greater than in terrestrial power plants, and the reactors tend to have a fast neutron spectrum. Currently, a new generation of space reactor power plants is being developed. The major effort is in the SP-100 program, where the power plant is being designed for seven years of full power, and no maintenance operation at a reactor outlet operating temperature of 1350 K

  13. The Uniqueness of Islamic Culture

    Directory of Open Access Journals (Sweden)

    Sinan YILMAZ

    2014-12-01

    Full Text Available Abstract This paper examines the main reasons behind why Islamic culture is different than other cultures. In the introduction part of the paper, the usage area of the words culture and civilization were tackled. In the first part of the paper, an evaluation of the uniqueness of Islamic culture was made and examples about this were given. In the second part of the paper, evaluations about how Islamic culture has struggled with modernization and secularization and how it has shaped itself as a result of this were made. In the third part of the paper, the situation in which Islamic civilization has regressed against the Western civilization causing emerging arguments and the current situation in Islamic civilization have been addressed by making evaluations on culture and civilization. In the final part, evaluations on thesis this paper has used were made.

  14. Unique properties of Drosophila spermatocyte primary cilia

    Directory of Open Access Journals (Sweden)

    Maria Giovanna Riparbelli

    2013-09-01

    The primary cilium is an essential organelle required for animal development and adult homeostasis that is found on most animal cells. The primary cilium contains a microtubule-based axoneme cytoskeleton that typically grows from the mother centriole in G0/G1 phase of the cell cycle as a membrane-bound compartment that protrudes from the cell surface. A unique system of bidirectional transport, intraflagellar transport (IFT, maintains the structure and function of cilia. While the axoneme is dynamic, growing and shrinking at its tip, at the same time it is very stable to the effects of microtubule-targeting drugs. The primary cilia found on Drosophila spermatocytes diverge from the general rules of primary cilium biology in several respects. Among these unique attributes, spermatocyte cilia assemble from all four centrioles in an IFT-independent manner in G2 phase, and persist continuously through two cell divisions. Here, we show that Drosophila spermatocyte primary cilia are extremely sensitive to microtubule-targeting drugs, unlike their mammalian counterparts. Spermatocyte cilia and their axonemes fail to assemble or be maintained upon nocodazole treatment, while centriole replication appears unperturbed. On the other hand, paclitaxel (Taxol, a microtubule-stabilizing drug, disrupted transition zone assembly and anchoring to the plasma membrane while causing spermatocyte primary cilia to grow extensively long during the assembly/elongation phase, but did not overtly affect the centrioles. However, once assembled to their mature length, spermatocyte cilia appeared unaffected by Taxol. The effects of these drugs on axoneme dynamics further demonstrate that spermatocyte primary cilia are endowed with unique assembly properties.

  15. Population structure analyses of Staphylococcus aureus at Tygerberg Hospital, South Africa, reveals a diverse population, a high prevalence of Panton-Valentine leukocidin genes, and unique local methicillin-resistant S. aureus clones

    NARCIS (Netherlands)

    Oosthuysen, W. F.; Orth, H.; Lombard, C. J.; Sinha, B.; Wasserman, E.

    Studies reporting on the population structure of Staphylococcus aureus in South Africa have focused only on methicillin-resistant S. aureus (MRSA). This study describes the population structure of S. aureus, including methicillin-susceptible S. aureus (MSSA) isolated from patients at Tygerberg

  16. Unmanned Aerial Vehicles unique cost estimating requirements

    Science.gov (United States)

    Malone, P.; Apgar, H.; Stukes, S.; Sterk, S.

    Unmanned Aerial Vehicles (UAVs), also referred to as drones, are aerial platforms that fly without a human pilot onboard. UAVs are controlled autonomously by a computer in the vehicle or under the remote control of a pilot stationed at a fixed ground location. There are a wide variety of drone shapes, sizes, configurations, complexities, and characteristics. Use of these devices by the Department of Defense (DoD), NASA, civil and commercial organizations continues to grow. UAVs are commonly used for intelligence, surveillance, reconnaissance (ISR). They are also use for combat operations, and civil applications, such as firefighting, non-military security work, surveillance of infrastructure (e.g. pipelines, power lines and country borders). UAVs are often preferred for missions that require sustained persistence (over 4 hours in duration), or are “ too dangerous, dull or dirty” for manned aircraft. Moreover, they can offer significant acquisition and operations cost savings over traditional manned aircraft. Because of these unique characteristics and missions, UAV estimates require some unique estimating methods. This paper describes a framework for estimating UAV systems total ownership cost including hardware components, software design, and operations. The challenge of collecting data, testing the sensitivities of cost drivers, and creating cost estimating relationships (CERs) for each key work breakdown structure (WBS) element is discussed. The autonomous operation of UAVs is especially challenging from a software perspective.

  17. 2XIIB vacuum vessel: a unique design

    International Nuclear Information System (INIS)

    Hibbs, S.M.; Calderon, M.O.

    1975-01-01

    The 2XIIB mirror confinement experiment makes unique demands on its vacuum system. The confinement coil set encloses a cavity whose surface is comprised of both simple and compound curves. Within this cavity and at the core of the machine is the operating vacuum which is on the order of 10 -9 Torr. The vacuum container fits inside the cavity, presenting an inside surface suitable for titanium getter pumping and a means of removing the heat load imposed by incandescent sublimator wires. In addition, the cavity is constructed of nonmagnetic and nonconducting materials (nonmetals) to avoid distortion of the pulsed confinement field. It is also isolated from mechanical shocks induced in the machine's main structure when the coils are pulsed. This paper describes the design, construction, and operation of the 2XIIB high-vacuum vessel that has been performing successfully since early 1974

  18. Density functional theory calculations for the band gap and formation energy of Pr4-xCaxSi12O3+xN18-x; a highly disordered compound with low symmetry and a large cell size.

    Science.gov (United States)

    Hong, Sung Un; Singh, Satendra Pal; Pyo, Myoungho; Park, Woon Bae; Sohn, Kee-Sun

    2017-06-28

    A novel oxynitride compound, Pr 4-x Ca x Si 12 O 3+x N 18-x , synthesized using a solid-state route has been characterized as a monoclinic structure in the C2 space group using Rietveld refinement on synchrotron powder X-ray diffraction data. The crystal structure of this compound was disordered due to the random distribution of Ca/Pr and N/O ions at various Wyckoff sites. A pragmatic approach for an ab initio calculation based on density function theory (DFT) for this disordered compound has been implemented to calculate an acceptable value of the band gap and formation energy. In general, for the DFT calculation of a disordered compound, a sufficiently large super cell and infinite variety of ensemble configurations is adopted to simulate the random distribution of ions; however, such an approach is time consuming and cost ineffective. Even a single unit cell model gave rise to 43 008 independent configurations as an input model for the DFT calculations. Since it was nearly impossible to calculate the formation energy and the band gap energy for all 43 008 configurations, an elitist non-dominated sorting genetic algorithm (NSGA-II) was employed to find the plausible configurations. In the NSGA-II, all 43 008 configurations were mathematically treated as genomes and the calculated band gap and the formation energy as the objective (fitness) function. Generalized gradient approximation (GGA) was first employed in the preliminary screening using NSGA-II, and thereafter a hybrid functional calculation (HSE06) was executed only for the most plausible GGA-relaxed configurations with lower formation and higher band gap energies. The final band gap energy (3.62 eV) obtained after averaging over the selected configurations, resembles closely the experimental band gap value (4.11 eV).

  19. Heart Failure: Unique to Older Adults

    Science.gov (United States)

    ... to Z › Heart Failure › Unique to Older Adults Font size A A A Print Share Glossary Unique ... will suffer from depression at some point. This type of severe depression is more serious than the ...

  20. Computational topology and the Unique Games Conjecture

    OpenAIRE

    Grochow, Joshua A.; Tucker-Foltz, Jamie

    2018-01-01

    Covering spaces of graphs have long been useful for studying expanders (as "graph lifts") and unique games (as the "label-extended graph"). In this paper we advocate for the thesis that there is a much deeper relationship between computational topology and the Unique Games Conjecture. Our starting point is Linial's 2005 observation that the only known problems whose inapproximability is equivalent to the Unique Games Conjecture - Unique Games and Max-2Lin - are instances of Maximum Section of...

  1. Structure-activity relationships of the unique and potent agouti-related protein (AGRP)-melanocortin chimeric Tyr-c[beta-Asp-His-DPhe-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH2 peptide template.

    Science.gov (United States)

    Wilczynski, Andrzej; Wilson, Krista R; Scott, Joseph W; Edison, Arthur S; Haskell-Luevano, Carrie

    2005-04-21

    The melanocortin receptor system consists of endogenous agonists, antagonists, G-protein coupled receptors, and auxiliary proteins that are involved in the regulation of complex physiological functions such as energy and weight homeostasis, feeding behavior, inflammation, sexual function, pigmentation, and exocrine gland function. Herein, we report the structure-activity relationship (SAR) of a new chimeric hAGRP-melanocortin agonist peptide template Tyr-c[beta-Asp-His-DPhe-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) that was characterized using amino acids previously reported in other melanocortin agonist templates. Twenty peptides were examined in this study, and six peptides were selected for (1)H NMR and computer-assisted molecular modeling structural analysis. The most notable results include the identification that modification of the chimeric template at the His position with Pro and Phe resulted in ligands that were nM mouse melanocortin-3 receptor (mMC3R) antagonists and nM mouse melanocortin-4 receptor (mMC4R) agonists. The peptides Tyr-c[beta-Asp-His-DPhe-Ala-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) and Tyr-c[beta-Asp-His-DNal(1')-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) resulted in 730- and 560-fold, respectively, mMC4R versus mMC3R selective agonists that also possessed nM agonist potency at the mMC1R and mMC5R. Structural studies identified a reverse turn occurring in the His-DPhe-Arg-Trp domain, with subtle differences observed that may account for the differences in melanocortin receptor pharmacology. Specifically, a gamma-turn secondary structure involving the DPhe(4) in the central position of the Tyr-c[beta-Asp-Phe-DPhe-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) peptide may differentiate the mixed mMC3R antagonist and mMC4R agonist pharmacology.

  2. Unique Fock quantization of scalar cosmological perturbations

    Science.gov (United States)

    Fernández-Méndez, Mikel; Mena Marugán, Guillermo A.; Olmedo, Javier; Velhinho, José M.

    2012-05-01

    We investigate the ambiguities in the Fock quantization of the scalar perturbations of a Friedmann-Lemaître-Robertson-Walker model with a massive scalar field as matter content. We consider the case of compact spatial sections (thus avoiding infrared divergences), with the topology of a three-sphere. After expanding the perturbations in series of eigenfunctions of the Laplace-Beltrami operator, the Hamiltonian of the system is written up to quadratic order in them. We fix the gauge of the local degrees of freedom in two different ways, reaching in both cases the same qualitative results. A canonical transformation, which includes the scaling of the matter-field perturbations by the scale factor of the geometry, is performed in order to arrive at a convenient formulation of the system. We then study the quantization of these perturbations in the classical background determined by the homogeneous variables. Based on previous work, we introduce a Fock representation for the perturbations in which: (a) the complex structure is invariant under the isometries of the spatial sections and (b) the field dynamics is implemented as a unitary operator. These two properties select not only a unique unitary equivalence class of representations, but also a preferred field description, picking up a canonical pair of field variables among all those that can be obtained by means of a time-dependent scaling of the matter field (completed into a linear canonical transformation). Finally, we present an equivalent quantization constructed in terms of gauge-invariant quantities. We prove that this quantization can be attained by a mode-by-mode time-dependent linear canonical transformation which admits a unitary implementation, so that it is also uniquely determined.

  3. 2.3-MW Medium-Voltage, Three-Level Wind Energy Inverter Applying a Unique Bus Structure and 4.5-kV Si/SiC Hybrid Isolated Power Modules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Erdman, W.; Keller, J.; Grider, D.; VanBrunt, E.

    2014-11-01

    A high-efficiency, 2.3-MW, medium-voltage, three-level inverter utilizing 4.5-kV Si/SiC (silicon carbide) hybrid modules for wind energy applications is discussed. The inverter addresses recent trends in siting the inverter within the base of multimegawatt turbine towers. A simplified split, three-layer laminated bus structure that maintains low parasitic inductances is introduced along with a low-voltage, high-current test method for determining these inductances. Feed-thru bushings, edge fill methods, and other design features of the laminated bus structure provide voltage isolation that is consistent with the 10.4-kV module isolation levels. Inverter efficiency improvement is a result of the (essential) elimination of the reverse recovery charge present in 4.5-kV Si PIN diodes, which can produce a significant reduction in diode turn-off losses as well as insulated-gate bipolar transistor (IGBT) turn-on losses. The hybrid modules are supplied in industry-standard 140 mm x 130 mm and 190 mm x 130 mm packages to demonstrate direct module substitution into existing inverter designs. A focus on laminated bus/capacitor-bank/module subassembly level switching performance is presented.

  4. EPR investigation into the structure of boron-containing quartz glasses

    International Nuclear Information System (INIS)

    Amosov, A.V.; Bushmarin, D.B.; Prokhorova, T.I.; Yudin, D.M.

    1975-01-01

    Certain properties of boron-containing quartz glasses and the nature of occurrence of boron in the glass lattice are studied as functions of the method of alloying. The formation of three types of borate structural nodes (BO 4 , BO 3 and BO 4 -BO 3 ) in the lattice of quartz glasses is established. Alloying by boron oxide up to 3% (weight) increases the crystallization stability of quartz glasses, lowers down tsub(g) from 1220 to 950 deg C and does not affect the coefficient of thermal expansion. Low symmetry of borate structural nodes, following from the analysis of EPR spectra, confirms the literature data concerning the low symmetry of glass-forming polyhedrons in a quartz glass

  5. Direct structural and spectroscopic investigation of ultrathin films of tetragonal CuO: Six-fold coordinated copper

    NARCIS (Netherlands)

    Samal, D.; Tan, H.; Takamura, Y.; Siemons, W.; Verbeeck, J.; van Tendeloo, G.; Arenholz, E.; Jenkins, A.; Rijnders, Augustinus J.H.M.; Koster, Gertjan

    2014-01-01

    Unlike other 3d transition metal monoxides (MnO, FeO, CoO, and NiO), CuO is found in a low-symmetry distorted monoclinic structure rather than the rocksalt structure. We report here of the growth of ultrathin CuO films on SrTiO3 substrates; scanning transmission electron microscopy was used to show

  6. Optimizing Nonlinear Beam Coupling in Low-Symmetry Crystals (Postprint)

    Science.gov (United States)

    2014-10-02

    input face normal and wavevector of the signal wave. The Debye screening length , `s = [εe f f ε0kBT/(Ne f f e2)]1/2, depends on the effective trap...interaction length inside the sample which is equal to the sample thickness in this case. 8 ution A. Approved for public release (PA): distribution...cos2 β + ε33 sin2 β + ε13 sin2β )/ε11 , (7) where `sX stands for Debye constant along the x-axis. In the first case (5◦) charge screening is strongly

  7. Nuclear magnetic resonance in low-symmetry superconductors

    Science.gov (United States)

    Cavanagh, D. C.; Powell, B. J.

    2018-01-01

    We consider the nuclear spin-lattice relaxation rate 1 /T1 in superconductors with accidental nodes, i.e., zeros of the order parameter that are not enforced by its symmetries. Such nodes in the superconducting gap are not constrained by symmetry to a particular position on the Fermi surface. We show, analytically and numerically, that a Hebel-Slichter-like peak occurs even in the absence of an isotropic component of the superconducting gap. For a gap with symmetry-required nodes the Fermi velocity at the node must point along the node. For accidental nodes this is not, in general, the case. This leads to additional terms in spectral function and hence the density of states. These terms lead to a logarithmic divergence in 1 /T1T at T →Tc- in models neglecting disorder and interactions [except for those leading to superconductivity; here T is temperature, Tc-=limδ→0(Tc-δ ) , and Tc is the critical temperature]. This contrasts with the usual Hebel-Slichter peak which arises from the coherence factors due to the isotropic component of the gap and leads to a divergence in 1 /T1T somewhat below Tc. The divergence in superconductors with accidental nodes is controlled by either disorder or additional electron-electron interactions. However, for reasonable parameters, neither of these effects removes the peak altogether. This provides a simple experimental method to distinguish between symmetry-required and accidental nodes.

  8. Unique Physician Identification Number (UPIN) Directory

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Unique Physician Identification Number (UPIN) Directory contains selected information on physicians, doctors of Osteopathy, limited licensed practitioners and...

  9. Uniqueness of time-independent electromagnetic fields

    DEFF Research Database (Denmark)

    Karlsson, Per W.

    1974-01-01

    As a comment on a recent paper by Steele, a more general uniqueness theorem for time-independent fields is mentioned. ©1974 American Institute of Physics......As a comment on a recent paper by Steele, a more general uniqueness theorem for time-independent fields is mentioned. ©1974 American Institute of Physics...

  10. Unique specification of Yang-Mills solutions

    International Nuclear Information System (INIS)

    Campbell, W.B.; Joseph, D.W.; Morgan, T.A.

    1980-01-01

    Screened time-independent cylindrically-symmetric solutions of Yang-Mills equations are given which show that the source does not uniquely determine the field. However, these particular solutions suggest a natural way of uniquely specifying solutions in terms of a physical realization of a symmetry group. (orig.)

  11. Constructing Dense Graphs with Unique Hamiltonian Cycles

    Science.gov (United States)

    Lynch, Mark A. M.

    2012-01-01

    It is not difficult to construct dense graphs containing Hamiltonian cycles, but it is difficult to generate dense graphs that are guaranteed to contain a unique Hamiltonian cycle. This article presents an algorithm for generating arbitrarily large simple graphs containing "unique" Hamiltonian cycles. These graphs can be turned into dense graphs…

  12. Uniqueness conditions for finitely dependent random fields

    International Nuclear Information System (INIS)

    Dobrushin, R.L.; Pecherski, E.A.

    1981-01-01

    The authors consider a random field for which uniqueness and some additional conditions guaranteeing that the correlations between the variables of the field decrease rapidly enough with the distance between the values of the parameter occur. The main result of the paper states that in such a case uniqueness is true for any other field with transition probabilities sufficiently close to those of the original field. Then they apply this result to some ''degenerate'' classes of random fields for which one can check this condition of correlation to decay, and thus obtain some new conditions of uniqueness. (Auth.)

  13. Peatlands as a unique climatic hotspots

    Science.gov (United States)

    Slowinska, S.; Marcisz, K.; Slowinski, M. M.; Blazejczyk, K.; Lamentowicz, M.

    2017-12-01

    Peatlands are unique environments, often acting as microrefugia of various taxa. High groundwater table, organic soils, specific vegetation and topography are important determinants of their local climatic conditions. However, relations between those determinants are not stable. For example, seasonal changes in weather patterns, hydrological dynamics, and local vegetation may alter microclimate. Additionally, long-term changes are important factor, as for example overgrowing due to significant change of microclimate conditions, what in turn changes geochemical and biological processes in the peat layer. We have been investigating interactions between abiotic and biotic factors of a small Sphagnum mire (ca. 6.0 ha) for over ten years now. The mire is located in Poland in transitional temperate climate and is the only place in polish lowlands where glacial relict Betula nana occurs. Identification of local climate of the mire, its microclimatic differentiation and its influence on surroundings were objectives of the study. We recorded water level fluctuations, photosynthetically active radiation (PAR), air temperature and humidity, and peat temperature at five monitoring plots at the mire and observed significant differences between them. We also investigated Sphagnum mosses growth and testate amoeba diversity and community structure to understand biological response of those differences. We observed that local climate of the mire was significantly different from open area reference place, it was much colder especially during nights. The average minimal temperature at the height 30 cm for growing seasons 2010-2012 was 3.7oC lower there and ground frosts occurred even in the summer. The climate of the mire affected the forest directly adjacent to it, and depending on weather conditions the strength and the distance of this interaction was different. Our results show that micro-environmental changes affects on biological processes and should be taken into consideration

  14. Classical many-particle systems with unique disordered ground states

    Science.gov (United States)

    Zhang, G.; Stillinger, F. H.; Torquato, S.

    2017-10-01

    Classical ground states (global energy-minimizing configurations) of many-particle systems are typically unique crystalline structures, implying zero enumeration entropy of distinct patterns (aside from trivial symmetry operations). By contrast, the few previously known disordered classical ground states of many-particle systems are all high-entropy (highly degenerate) states. Here we show computationally that our recently proposed "perfect-glass" many-particle model [Sci. Rep. 6, 36963 (2016), 10.1038/srep36963] possesses disordered classical ground states with a zero entropy: a highly counterintuitive situation . For all of the system sizes, parameters, and space dimensions that we have numerically investigated, the disordered ground states are unique such that they can always be superposed onto each other or their mirror image. At low energies, the density of states obtained from simulations matches those calculated from the harmonic approximation near a single ground state, further confirming ground-state uniqueness. Our discovery provides singular examples in which entropy and disorder are at odds with one another. The zero-entropy ground states provide a unique perspective on the celebrated Kauzmann-entropy crisis in which the extrapolated entropy of a supercooled liquid drops below that of the crystal. We expect that our disordered unique patterns to be of value in fields beyond glass physics, including applications in cryptography as pseudorandom functions with tunable computational complexity.

  15. Tattoos and piercings: bodily expressions of uniqueness?

    Science.gov (United States)

    Tiggemann, Marika; Hopkins, Louise A

    2011-06-01

    The study aimed to investigate the motivations underlying the body modification practices of tattooing and piercing. There were 80 participants recruited from an Australian music store, who provided descriptions of their tattoos and piercings and completed measures of need for uniqueness, appearance investment and distinctive appearance investment. It was found that tattooed individuals scored significantly higher on need for uniqueness than non-tattooed individuals. Further, individuals with conventional ear piercings scored significantly lower on need for uniqueness than individuals with no piercings or with facial and body piercings. Neither appearance investment nor distinctive appearance investment differed significantly among tattoo or piercing status groups. Strength of identification with music was significantly correlated with number of tattoos, but not number of piercings. It was concluded that tattooing, but not body piercing, represents a bodily expression of uniqueness. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. High Blood Pressure: Unique to Older Adults

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z High Blood Pressure Hypertension Unique to Older Adults This section provides ... Pressure Targets are Different for Very Old Adults High blood pressure (also called hypertension) increases your chance of having ...

  17. unique determination of structure and velocity by 3-d tomographic ...

    African Journals Online (AJOL)

    ADMIN

    In this paper the cause of this velocity-depth ambiguity is examined and a methodology is proposed that ..... Thus the matrix. A has a null space and we have infinite solution ... acquired in the North Sea along 10 parallel profiles with a ship ...

  18. Nondestructive Detection of Structural Damage Uniquely Associated with Fatigue

    Science.gov (United States)

    1974-07-01

    corrosion were not as numerous as cracks caused by fatigue. Stress corrosion cracking occurred mostly at fillet radius, shear pinhole, and the web of...nil i. i^mji^mitm^mm^mmmmmw^mmmtmi>i>i.vi\\ -^^ wix ^w 0) a E re i A c 0) 1- D o ^el /l Current le // T wi th ~ transducer — ’"A

  19. Waved graphene: Unique structure for the adsorption of small molecules

    International Nuclear Information System (INIS)

    Pan, Hui

    2017-01-01

    We propose waved graphenes for the strong adsorption of molecules and investigate their potential applications. We find that the physical adsorption of molecules on waved graphene is greatly enhanced by compression. At optimal compression, the physical adsorption energies of H_2, N_2, NO, and CO are increased by 6–9 times, and that for O_2 is more than 2 times. We show that the energy for their chemical adsorption on waved graphene decreases dramatically with the increment of compression. The energy of dissociation of H_2 on flat graphene is 1.63 eV and reduced to 0.06 eV (96% reduction) on waved graphene at a compression of 50%, respectively. The energy for chemical adsorption of O_2 on waved graphenes is extremely reduced from 0.98 eV to −0.57 eV as with compression increasing from 0 to 50%, indicating the transition of endothermic chemical adsorption to exothermic. We further show that the electronic properties of waved graphenes are modified, leading to the change of electrical characters. We see that the waved graphenes may find applications in gas storage, sensor and catalyst because of enhanced physical and chemical adsorption and the induced change of electronic properties. - Highlights: • Adsorption of small molecules on waved graphene is greatly enhanced. • Strong physical adsorption in the trough of waved graphene can be achieved by tuning the curvature. • Chemical adsorption is on the crest of waved graphene. • Exothermic dissociation of H2 and O2 can be realized on waved graphene under high compression. • Wave graphene can be candidates as catalysts and gas storage/sensor.

  20. Waved graphene: Unique structure for the adsorption of small molecules

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Hui, E-mail: huipan@umac.mo

    2017-03-01

    We propose waved graphenes for the strong adsorption of molecules and investigate their potential applications. We find that the physical adsorption of molecules on waved graphene is greatly enhanced by compression. At optimal compression, the physical adsorption energies of H{sub 2}, N{sub 2}, NO, and CO are increased by 6–9 times, and that for O{sub 2} is more than 2 times. We show that the energy for their chemical adsorption on waved graphene decreases dramatically with the increment of compression. The energy of dissociation of H{sub 2} on flat graphene is 1.63 eV and reduced to 0.06 eV (96% reduction) on waved graphene at a compression of 50%, respectively. The energy for chemical adsorption of O{sub 2} on waved graphenes is extremely reduced from 0.98 eV to −0.57 eV as with compression increasing from 0 to 50%, indicating the transition of endothermic chemical adsorption to exothermic. We further show that the electronic properties of waved graphenes are modified, leading to the change of electrical characters. We see that the waved graphenes may find applications in gas storage, sensor and catalyst because of enhanced physical and chemical adsorption and the induced change of electronic properties. - Highlights: • Adsorption of small molecules on waved graphene is greatly enhanced. • Strong physical adsorption in the trough of waved graphene can be achieved by tuning the curvature. • Chemical adsorption is on the crest of waved graphene. • Exothermic dissociation of H2 and O2 can be realized on waved graphene under high compression. • Wave graphene can be candidates as catalysts and gas storage/sensor.

  1. Theory of structural phase transition in MgTi{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Talanov, V. M., E-mail: valtalanov@mail.ru [South Russian State Polytechnical University (Russian Federation); Shirokov, V. B. [Russian Academy of Sciences, South Science Centre (Russian Federation); Ivanov, V. V. [South Russian State Polytechnical University (Russian Federation); Talanov, M. V. [South Federal University (Russian Federation)

    2015-01-15

    A theory of phase transition in MgTi{sub 2}O{sub 4} is proposed based on a study of the order-parameter symmetry, thermodynamics, and mechanisms of formation of the atomic and orbital structure of the low-symmetry MgTi{sub 2}O{sub 4} phase. The critical order parameter (which induces a phase transition) is determined. It is shown that the calculated MgTi{sub 2}O{sub 4} tetragonal structure is a result of displacements of magnesium, titanium, and oxygen atoms; ordering of oxygen atoms; and the participation of d{sub xy}, d{sub xz}, and d{sub yz} orbitals. The contribution of noncritical representations to ion displacements is proven to be insignificant. The existence of various metal clusters in the tetragonal phase has been established by calculation in correspondence with experimental data. It is shown (within the Landau theory of phase transitions) that phase states can be changed as a result of both first- and second-order phase transitions: the high-symmetry phase borders two low-symmetry phases by second-order transition lines, while the border between low-symmetry phases is a first-order transition line.

  2. Modularity, comparative cognition and human uniqueness.

    Science.gov (United States)

    Shettleworth, Sara J

    2012-10-05

    Darwin's claim 'that the difference in mind between man and the higher animals … is certainly one of degree and not of kind' is at the core of the comparative study of cognition. Recent research provides unprecedented support for Darwin's claim as well as new reasons to question it, stimulating new theories of human cognitive uniqueness. This article compares and evaluates approaches to such theories. Some prominent theories propose sweeping domain-general characterizations of the difference in cognitive capabilities and/or mechanisms between adult humans and other animals. Dual-process theories for some cognitive domains propose that adult human cognition shares simple basic processes with that of other animals while additionally including slower-developing and more explicit uniquely human processes. These theories are consistent with a modular account of cognition and the 'core knowledge' account of children's cognitive development. A complementary proposal is that human infants have unique social and/or cognitive adaptations for uniquely human learning. A view of human cognitive architecture as a mosaic of unique and species-general modular and domain-general processes together with a focus on uniquely human developmental mechanisms is consistent with modern evolutionary-developmental biology and suggests new questions for comparative research.

  3. Two Galaxies for a Unique Event

    Science.gov (United States)

    2009-04-01

    To celebrate the 100 Hours of Astronomy, ESO is sharing two stunning images of unusual galaxies, both belonging to the Sculptor group of galaxies. The images, obtained at two of ESO's observatories at La Silla and Paranal in Chile, illustrate the beauty of astronomy. ESO PR Photo 14a/09 Irregular Galaxy NGC 55 ESO PR Photo 14b/09 Spiral Galaxy NGC 7793 As part of the International Year of Astronomy 2009 Cornerstone project, 100 Hours of Astronomy, the ambitious "Around the World in 80 Telescopes" event is a unique live webcast over 24 hours, following night and day around the globe to some of the most advanced observatories on and off the planet. To provide a long-lasting memory of this amazing world tour, observatories worldwide are revealing wonderful, and previously unseen, astronomical images. For its part, ESO is releasing outstanding pictures of two galaxies, observed with telescopes at the La Silla and Paranal observatories. The first of these depicts the irregular galaxy NGC 55, a member of the prominent Sculptor group of galaxies in the southern constellation of Sculptor. The galaxy is about 70 000 light-years across, that is, a little bit smaller than our own Milky Way. NGC 55 actually resembles more our galactic neighbour, the Large Magellanic Cloud (LMC), although the LMC is seen face-on, whilst NGC 55 is edge-on. By studying about 20 planetary nebulae in this image, a team of astronomers found that NGC 55 is located about 7.5 million light-years away. They also found that the galaxy might be forming a bound pair with the gorgeous spiral galaxy NGC 300 . Planetary nebulae are the final blooming of Sun-like stars before their retirement as white dwarfs. This striking image of NGC 55, obtained with the Wide Field Imager on the 2.2-metre MPG/ESO telescope at La Silla, is dusted with a flurry of reddish nebulae, created by young, hot massive stars. Some of the more extended ones are not unlike those seen in the LMC, such as the Tarantula Nebula. The quality

  4. Marketing the Uniqueness of Small Towns. Revised.

    Science.gov (United States)

    Dunn, Douglas; Hogg, David H.

    The key to marketing a town is determining and promoting the town's "differential advantage" or uniqueness that would make people want to visit or live there. Exercises to help communities gain important insights into the town's competitive edge include a brainstorming session with knowledgeable community members, a visitor…

  5. On uniqueness in evolution quasivariational inequalities

    Czech Academy of Sciences Publication Activity Database

    Brokate, M.; Krejčí, Pavel; Schnabel, H.

    2004-01-01

    Roč. 11, č. 1 (2004), s. 111-130 ISSN 0944-6532 Institutional research plan: CEZ:AV0Z1019905 Keywords : evolution quasivariational inequality * uniqueness * sweeping process Subject RIV: BA - General Mathematics Impact factor: 0.425, year: 2004 http://www.heldermann-verlag.de/jca/jca11/jca0386.pdf

  6. Esperanto: A Unique Model for General Linguistics.

    Science.gov (United States)

    Dulichenko, Aleksandr D.

    1988-01-01

    Esperanto presents a unique model for linguistic research by allowing the study of language development from project to fully functioning language. Esperanto provides insight into the growth of polysemy and redundancy, as well as into language universals and the phenomenon of social control. (Author/CB)

  7. Weeping dragon, a unique ornamenal citrus

    Science.gov (United States)

    ‘Weeping Dragon’ is a new ornamental citrus cultivar developed by intercrossing of two unusual and unique citrus types, Poncirus trifoliata cultivated variety (cv.) Flying Dragon, and Citrus sinensis cv. ‘Cipo’. This new hybrid cultivar combines strongly contorted and weeping growth traits in a smal...

  8. The end of the unique myocardial band

    DEFF Research Database (Denmark)

    MacIver, David H; Partridge, John B; Agger, Peter

    2018-01-01

    Two of the leading concepts of mural ventricular architecture are the unique myocardial band and the myocardial mesh model. We have described, in an accompanying article published in this journal, how the anatomical, histological and high-resolution computed tomographic studies strongly favour th...

  9. Unique microstructure and excellent mechanical properties of ADI

    Directory of Open Access Journals (Sweden)

    Jincheng Liu

    2006-11-01

    Full Text Available Amongst the cast iron family, ADI has a unique microstructure and an excellent, optimised combination of mechanical properties. The main microstructure of ADI is ausferrite, which is a mixture ofextremely fine acicular ferrite and stable, high carbon austenite. There are two types of austenite in ADI:(1 the coarser and more equiaxed blocks of austenite between non-parallel acicular structures, which exist mainly in the last solidified area, and (2 the thin films of ustenite between the individual ferriteplatelets in the acicular structure. It is this unique microstructure, which gives ADI its excellent static and dynamic properties, and good low temperature impact toughness. The effect of microstructure on the mechanical properties is explained in more detail by examining the microstructure at the atomic scale. Considering the nanometer grain sizes, the unique microstructure, the excellent mechanical properties,good castability, (which enables near net shape components to be produced economically and in large volumes, and the fact that it can be 100% recycled, it is not overemphasized to call ADI a high-tech,nanometer and “green” material. ADI still has the potential to be further improved and its production and the number of applications for ADI will continue to grow, driven by the resultant cost savings over alternative materials.

  10. [Uniqueness seeking behavior as a self-verification: an alternative approach to the study of uniqueness].

    Science.gov (United States)

    Yamaoka, S

    1995-06-01

    Uniqueness theory explains that extremely high perceived similarity between self and others evokes negative emotional reactions and causes uniqueness seeking behavior. However, the theory conceptualizes similarity so ambiguously that it appears to suffer from low predictive validity. The purpose of the current article is to propose an alternative explanation of uniqueness seeking behavior. It posits that perceived uniqueness deprivation is a threat to self-concepts, and therefore causes self-verification behavior. Two levels of self verification are conceived: one based on personal categorization and the other on social categorization. The present approach regards uniqueness seeking behavior as the personal-level self verification. To test these propositions, a 2 (very high or moderate similarity information) x 2 (with or without outgroup information) x 2 (high or low need for uniqueness) between-subject factorial-design experiment was conducted with 95 university students. Results supported the self-verification approach, and were discussed in terms of effects of uniqueness deprivation, levels of self-categorization, and individual differences in need for uniqueness.

  11. Non-unique factorizations algebraic, combinatorial and analytic theory

    CERN Document Server

    Geroldinger, Alfred

    2006-01-01

    From its origins in algebraic number theory, the theory of non-unique factorizations has emerged as an independent branch of algebra and number theory. Focused efforts over the past few decades have wrought a great number and variety of results. However, these remain dispersed throughout the vast literature. For the first time, Non-Unique Factorizations: Algebraic, Combinatorial, and Analytic Theory offers a look at the present state of the theory in a single, unified resource.Taking a broad look at the algebraic, combinatorial, and analytic fundamentals, this book derives factorization results and applies them in concrete arithmetical situations using appropriate transfer principles. It begins with a basic introduction that can be understood with knowledge of standard basic algebra. The authors then move to the algebraic theory of monoids, arithmetic theory of monoids, the structure of sets of lengths, additive group theory, arithmetical invariants, and the arithmetic of Krull monoids. They also provide a s...

  12. Multiple floating metatarsals: a unique injury

    Directory of Open Access Journals (Sweden)

    Trikha Vivek

    2013-04-01

    Full Text Available 【Abstract】Concomitant dislocation of the tar-sometatarsal and metatarsophalangeal joints of foot is an extremely rare injury. Such injuries presenting in a single or adjacent dual rays have been described in few cases previously. We describe such an injury in adjacent three metatarsals of a polytrauma patient. These injuries are likely to be missed in the initial assessment of a polytrauma patient. These patients are at risk of an overlooked diagnosis but the consequences of missing this type of injury may be Vivek Trikha*, Tarun Goyal, Amit K Agarwal quite severe. This case is presented in view of its unique-ness along with possible mechanism of injury, the sequence of reduction and follow-up. Knowledge of such injury and its proper management may be useful to the trauma surgeons. Key words: Metatarsal bones; Metatarsophalangeal joint; Wounds and injuries

  13. Modularity, comparative cognition and human uniqueness

    OpenAIRE

    Shettleworth, Sara J.

    2012-01-01

    Darwin's claim ‘that the difference in mind between man and the higher animals … is certainly one of degree and not of kind’ is at the core of the comparative study of cognition. Recent research provides unprecedented support for Darwin's claim as well as new reasons to question it, stimulating new theories of human cognitive uniqueness. This article compares and evaluates approaches to such theories. Some prominent theories propose sweeping domain-general characterizations of the difference ...

  14. A unique theory of all forces

    International Nuclear Information System (INIS)

    Di Vecchia, Paolo

    1997-01-01

    In discussing the construction of a consistent theory of quantum gravity unified with the gauge interactions we are naturally led to a string theory. We review its properties and the five consistent supersymmetric string theories in ten dimensions. We finally discuss the evidence that these theories are actually special limits of a unique 11-dimensional theory, called M-theory, and a recent conjecture for its explicit formulation as a supersymmetric Matrix theory

  15. Uniqueness and non-uniqueness of semigroups generated by singular diffusion operators

    CERN Document Server

    Eberle, Andreas

    1999-01-01

    This book addresses both probabilists working on diffusion processes and analysts interested in linear parabolic partial differential equations with singular coefficients. The central question discussed is whether a given diffusion operator, i.e., a second order linear differential operator without zeroth order term, which is a priori defined on test functions over some (finite or infinite dimensional) state space only, uniquely determines a strongly continuous semigroup on a corresponding weighted Lp space. Particular emphasis is placed on phenomena causing non-uniqueness, as well as on the relation between different notions of uniqueness appearing in analytic and probabilistic contexts.

  16. Unique supply function equilibrium with capacity constraints

    International Nuclear Information System (INIS)

    Holmberg, Paer

    2008-01-01

    Consider a market where producers submit supply functions to a procurement auction with uncertain demand, e.g. an electricity auction. In the Supply Function Equilibrium (SFE), every firm commits to the supply function that maximises expected profit in the one-shot game given the supply functions of competitors. A basic weakness of the SFE is the presence of multiple equilibria. This paper shows that with (i) symmetric producers, (ii) perfectly inelastic demand, (iii) a price cap, and (iv) capacity constraints that bind with a positive probability, there exists a unique, symmetric SFE. (author)

  17. Stationary Black Holes: Uniqueness and Beyond

    Directory of Open Access Journals (Sweden)

    Heusler Markus

    1998-01-01

    Full Text Available The spectrum of known black hole solutions to the stationary Einstein equations has increased in an unexpected way during the last decade. In particular, it has turned out that not all black hole equilibrium configurations are characterized by their mass, angular momentum and global charges. Moreover, the high degree of symmetry displayed by vacuum and electro-vacuum black hole space-times ceases to exist in self-gravitating non-linear field theories. This text aims to review some of the recent developments and to discuss them in the light of the uniqueness theorem for the Einstein-Maxwell system.

  18. Stationary Black Holes: Uniqueness and Beyond

    Directory of Open Access Journals (Sweden)

    Piotr T. Chruściel

    2012-05-01

    Full Text Available The spectrum of known black-hole solutions to the stationary Einstein equations has been steadily increasing, sometimes in unexpected ways. In particular, it has turned out that not all black-hole-equilibrium configurations are characterized by their mass, angular momentum and global charges. Moreover, the high degree of symmetry displayed by vacuum and electro vacuum black-hole spacetimes ceases to exist in self-gravitating non-linear field theories. This text aims to review some developments in the subject and to discuss them in light of the uniqueness theorem for the Einstein-Maxwell system.

  19. On uniqueness in diffuse optical tomography

    International Nuclear Information System (INIS)

    Harrach, Bastian

    2009-01-01

    A prominent result of Arridge and Lionheart (1998 Opt. Lett. 23 882–4) demonstrates that it is in general not possible to simultaneously recover both the diffusion (aka scattering) and the absorption coefficient in steady-state (dc) diffusion-based optical tomography. In this work we show that it suffices to restrict ourselves to piecewise constant diffusion and piecewise analytic absorption coefficients to regain uniqueness. Under this condition both parameters can simultaneously be determined from complete measurement data on an arbitrarily small part of the boundary

  20. Young children's preference for unique owned objects.

    Science.gov (United States)

    Gelman, Susan A; Davidson, Natalie S

    2016-10-01

    An important aspect of human thought is the value we place on unique individuals. Adults place higher value on authentic works of art than exact replicas, and young children at times value their original possessions over exact duplicates. What is the scope of this preference in early childhood, and when do children understand its subjective nature? On a series of trials, we asked three-year-olds (N=36) to choose between two toys for either themselves or the researcher: an old (visibly used) toy vs. a new (more attractive) toy matched in type and appearance (e.g., old vs. brand-new blanket). Focal pairs contrasted the child's own toy with a matched new object; Control pairs contrasted toys the child had never seen before. Children preferred the old toys for Focal pairs only, and treated their own preferences as not shared by the researcher. By 3years of age, young children place special value on unique individuals, and understand the subjective nature of that value. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Event segmentation ability uniquely predicts event memory.

    Science.gov (United States)

    Sargent, Jesse Q; Zacks, Jeffrey M; Hambrick, David Z; Zacks, Rose T; Kurby, Christopher A; Bailey, Heather R; Eisenberg, Michelle L; Beck, Taylor M

    2013-11-01

    Memory for everyday events plays a central role in tasks of daily living, autobiographical memory, and planning. Event memory depends in part on segmenting ongoing activity into meaningful units. This study examined the relationship between event segmentation and memory in a lifespan sample to answer the following question: Is the ability to segment activity into meaningful events a unique predictor of subsequent memory, or is the relationship between event perception and memory accounted for by general cognitive abilities? Two hundred and eight adults ranging from 20 to 79years old segmented movies of everyday events and attempted to remember the events afterwards. They also completed psychometric ability tests and tests measuring script knowledge for everyday events. Event segmentation and script knowledge both explained unique variance in event memory above and beyond the psychometric measures, and did so as strongly in older as in younger adults. These results suggest that event segmentation is a basic cognitive mechanism, important for memory across the lifespan. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Edges and vertices in a unique signed circle in a signed graph

    Directory of Open Access Journals (Sweden)

    Richard Behr

    2017-12-01

    Full Text Available We examine the conditions under which a signed graph contains an edge or a vertex that is contained in a unique negative circle or a unique positive circle. For an edge in a unique signed circle, the positive and negative case require the same structure on the underlying graph, but the requirements on the signature are different. We characterize the structure of the underlying graph necessary to support such an edge in terms of bridges of a circle. We then use the results from the edge version of the problem to help solve the vertex version.

  3. Unique sodium phosphosilicate glasses designed through extended topological constraint theory.

    Science.gov (United States)

    Zeng, Huidan; Jiang, Qi; Liu, Zhao; Li, Xiang; Ren, Jing; Chen, Guorong; Liu, Fude; Peng, Shou

    2014-05-15

    Sodium phosphosilicate glasses exhibit unique properties with mixed network formers, and have various potential applications. However, proper understanding on the network structures and property-oriented methodology based on compositional changes are lacking. In this study, we have developed an extended topological constraint theory and applied it successfully to analyze the composition dependence of glass transition temperature (Tg) and hardness of sodium phosphosilicate glasses. It was found that the hardness and Tg of glasses do not always increase with the content of SiO2, and there exist maximum hardness and Tg at a certain content of SiO2. In particular, a unique glass (20Na2O-17SiO2-63P2O5) exhibits a low glass transition temperature (589 K) but still has relatively high hardness (4.42 GPa) mainly due to the high fraction of highly coordinated network former Si((6)). Because of its convenient forming and manufacturing, such kind of phosphosilicate glasses has a lot of valuable applications in optical fibers, optical amplifiers, biomaterials, and fuel cells. Also, such methodology can be applied to other types of phosphosilicate glasses with similar structures.

  4. Self-interstitials structure in the hcp metals: A further perspective from first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Pasianot, Roberto C., E-mail: pasianot@cnea.gov.ar [Gerencia Materiales, CAC-CNEA, Avda. Gral. Paz 1499, 1650 San Martín (Argentina); CONICET, Godoy Cruz 2290, 1425 Buenos Aires (Argentina); Instituto Sabato, UNSAM/CNEA, Avda. Gral. Paz 1499, 1650 San Martín (Argentina)

    2016-12-01

    We study the structure of several standard and non-standard self-interstitial configurations in a series of hcp metals, by using Density Functional Theory as embodied in the computer codes SIESTA and WIEN2k. The considered metals include Be, Mg, Ti, Zr, Co, Zn, and Cd, thus spanning the whole range of experimental c/a ratios, different kinds of bonding, and even magnetism (Co). The results show the importance of low symmetry configurations, closely related to the non-basal crowdion, in order to rationalize the experimental data on self-interstitial structure and migration.

  5. Detecting beer intake by unique metabolite patterns

    DEFF Research Database (Denmark)

    Gürdeniz, Gözde; Jensen, Morten Georg; Meier, Sebastian

    2016-01-01

    Evaluation of health related effects of beer intake is hampered by the lack of accurate tools for assessing intakes (biomarkers). Therefore, we identified plasma and urine metabolites associated with recent beer intake by untargeted metabolomics and established a characteristic metabolite pattern...... representing raw materials and beer production as a qualitative biomarker of beer intake. In a randomized, crossover, single-blinded meal study (MSt1) 18 participants were given one at a time four different test beverages: strong, regular and non-alcoholic beers and a soft drink. Four participants were...... assigned to have two additional beers (MSt2). In addition to plasma and urine samples, test beverages, wort and hops extract were analyzed by UPLC-QTOF. A unique metabolite pattern reflecting beer metabolome, including metabolites derived from beer raw material (i.e. N-methyl tyramine sulfate and the sum...

  6. Is physical space unique or optional

    International Nuclear Information System (INIS)

    Ekstein, H.; Centre National de la Recherche Scientifique, 13 - Marseille

    1975-02-01

    There are two concepts of the physical space-time. One, S(F), is that of a fixed arena in which events take place. The other S(D), is that of a space-time shaped by events. The second depends on the state (initial conditions) or on the external field, the first does not. The main assertions of the present paper are: 1) the fixed space-time S(F) is neither incompatibles with nor made superfluous, by Einstein's theory. S(F) is experimentally explorable, unique, and probably identical with Minkowski space M. 2) The dynamical space S(D) is largely optional. It can be chosen to be M, but the natural choice is Einstein's pseudo-Riemanian manifold [fr

  7. ARAC: A unique command and control resource

    International Nuclear Information System (INIS)

    Bradley, M.M.; Baskett, R.L.; Ellis, J.S.

    1996-04-01

    The Atmospheric Release Advisory Capability (ARAC) at Lawrence Livermore National Laboratory (LLNL) is a centralized federal facility designed to provide real-time, world-wide support to military and civilian command and control centers by predicting the impacts of inadvertent or intentional releases of nuclear, biological, or chemical materials into the atmosphere. ARAC is a complete response system consisting of highly trained and experienced personnel, continually updated computer models, redundant data collection systems, and centralized and remote computer systems. With over 20 years of experience responding to domestic and international incidents, strong linkages with the Department of Defense, and the ability to conduct classified operations, ARAC is a unique command and control resource

  8. ARAC: A unique command and control resource

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, M.M.; Baskett, R.L.; Ellis, J.S. [and others

    1996-04-01

    The Atmospheric Release Advisory Capability (ARAC) at Lawrence Livermore National Laboratory (LLNL) is a centralized federal facility designed to provide real-time, world-wide support to military and civilian command and control centers by predicting the impacts of inadvertent or intentional releases of nuclear, biological, or chemical materials into the atmosphere. ARAC is a complete response system consisting of highly trained and experienced personnel, continually updated computer models, redundant data collection systems, and centralized and remote computer systems. With over 20 years of experience responding to domestic and international incidents, strong linkages with the Department of Defense, and the ability to conduct classified operations, ARAC is a unique command and control resource.

  9. Unique computer system for safeguards use

    International Nuclear Information System (INIS)

    Kuckertz, T.H.; Pratt, J.C.

    1981-01-01

    Microprocessors have been used to implement specialized scientific data processing systems since 1976. One such system, the LeCroy 3500, is presently being used by the Detection and Verification Group of the Energy Division at Los Alamos National Laboratory for a large variety of tasks involving measurement of various nuclear parameters associated with radioactive materials. The system is unique because it can do not only sophisticated pulse height and multi-scale analyses but also other analyses that are limited only by the availability fo CAMAC modules that would acquire data from exotic experiments. The system is also field portable which extends the range of experiments that it can control. Four applications of this system are described in this paper: (1) plutonium storage vault monitoring, (2) coded aperture image reconstruction, (3) spatial distribution of gamma radiation, and (4) nuclear waste management. 7 figures

  10. The unique ethics of sports medicine.

    Science.gov (United States)

    Johnson, Rob

    2004-04-01

    The ethical code by which physicians traditionally conduct themselves is based on the relationship between the physician and the patient: both work toward the goal of improving or maintaining health. Constraints on this relationship may be behaviors of patient choice (tobacco use, excessive alcohol use, sedentary behavior, and so on). The athlete-physician relationship is ethically different. Influences such as the physician's employer, the athlete's desire to play with pain and injury, and the economic consequences of playing or not complicate medical decisions. This perspective suggests something different and even unique about the ethics of the sports medicine practitioner. This article explores the differences fostering the ethical tight ropes that sports physicians walk in their sports medicine practices.

  11. MRI: unique costing and pricing issues.

    Science.gov (United States)

    Schwartz, H W; Jarl, D F

    1985-01-01

    Acquisition of magnetic resonance imaging (MRI) involves a plethora of costs not traditionally encountered in radiology procedure cost accounting models. Experiences with MRI gained at the University of Minnesota Hospitals and Clinics during 1984 uncovered a wide variety of unique costing issues which were eventually identified at the time when the MRI hospital charge was being established. Our experience at UMHC can provide those radiology departments now acquiring MRI with an earlier awareness of these special costing issues, hopefully resulting in better and more timely data collection. Current reimbursement and pricing issues are also having a dramatic impact on MRI costs at each institution and must be assessed in terms of third-party payor intentions.

  12. Unique Turbinal Morphology in Horseshoe Bats (Chiroptera: Rhinolophidae).

    Science.gov (United States)

    Curtis, Abigail A; Simmons, Nancy B

    2017-02-01

    The mammalian nasal fossa contains a set of delicate and often structurally complex bones called turbinals. Turbinals and associated mucosae function in regulating respiratory heat and water loss, increasing surface area for olfactory tissue, and directing airflow within the nasal fossa. We used high-resolution micro-CT scanning to investigate a unique maxilloturbinal morphology in 37 species from the bat family Rhinolophidae, which we compared with those of families Hipposideridae, Megadermatidae, and Pteropodidae. Rhinolophids exhibit numerous structural modifications along the nasopharyngeal tract associated with emission of high duty cycle echolocation calls via the nostrils. In rhinolophids, we found that the maxilloturbinals and a portion of ethmoturbinal I form a pair of strand-like bony structures on each side of the nasal chamber. These structures project anteriorly from the transverse lamina and complete a hairpin turn to project posteriorly down the nasopharyngeal duct, and vary in length among species. The strand-like maxilloturbinals in Rhinolophidae were not observed in our outgroups and represent a synapomorphy for this family, and are unique in form among mammals. Within Rhinolophidae, maxilloturbinal size and cross-sectional shape were correlated with phylogeny. We hypothesize that strand-shaped maxilloturbinals may function to reduce respiratory heat and water loss without greatly impacting echolocation call transmission since they provide increased mucosal surface area for heat and moisture exchange but occupy minimal space. Alternatively, they may play a role in transmission of echolocation calls since they are located directly along the path sound travels between the larynx and nostrils during call emission. Anat Rec, 300:309-325, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Structuralism.

    Science.gov (United States)

    Piaget, Jean

    Provided is an overview of the analytical method known as structuralism. The first chapter discusses the three key components of the concept of a structure: the view of a system as a whole instead of so many parts; the study of the transformations in the system; and the fact that these transformations never lead beyond the system but always…

  14. The complex and unique ATLAS Toroid family

    CERN Multimedia

    2002-01-01

    Big parts for the toroid magnets that will be used in the ATLAS experiment have been continuously arriving at CERN since March. These structures will create the largest superconducting toroid magnet ever.

  15. Theory of uniqueness of Indian Caste System

    OpenAIRE

    Ashwin Kumar

    2006-01-01

    Classical studies on pre-modern Indian social structure have suggested apparent differences between the Indian caste system and social stratification as one can discern in other parts of the world. However, one needs to question such dogmatic assertions that such vast differences really existed. An endeavor is made in this research paper to reflect on the nature of caste hierarchy in pre-modern India. The caste system forms the significant basis of pre-modern Indian social structure. Early wr...

  16. Alpbach Summer School - a unique learning experience

    Science.gov (United States)

    Kern, K.; Aulinas, J.; Clifford, D.; Krejci, D.; Topham, R.

    2011-12-01

    The Alpbach Summer School is a ten-day program that provides a unique opportunity for young european science and engineering students, both undergraduate and graduate, to learn how to approach the entire design process of a space mission. The theme of the 2010 Summer School was "New Space Missions to Understand Climate Change", a current, challenging, very broad and complex topic. The program was established more than 35 years ago and is organised in two interrelated parts: a series of lectures held by renowned experts in the field (in the case of this specific year, climate change and space engineering experts) that provides a technical and scientific background for the workshops that follow, the core of the Summer School. For the workshops the students are split into four international, interdisciplinary teams of about 15 students. In 2010 every team had to complete a number of tasks, four in total: (1) identify climate change research gaps and design a space mission that has not yet been flown or proposed, (2) define the science objectives and requirements of the mission, (3) design a spacecraft that meets the mission requirements, which includes spacecraft design and construction, payload definition, orbit calculations, but also the satellite launch, operation and mission costs and (4) write up a short mission proposal and present the results to an expert review panel. Achieving these tasks in only a few days in a multicultural, interdisciplinary team represents a major challenge for all participants and provides an excellent practical learning experience. Over the course of the program, students do not just learn facts about climate change and space engineering, but scientists also learn from engineers and engineers from scientists. The participants have to deepen their knowledge in an often unfamiliar field, develop organisational and team-work skills and work under pressure. Moreover, teams are supported by team and roving tutors and get the opportunity to

  17. Detecting Beer Intake by Unique Metabolite Patterns.

    Science.gov (United States)

    Gürdeniz, Gözde; Jensen, Morten Georg; Meier, Sebastian; Bech, Lene; Lund, Erik; Dragsted, Lars Ove

    2016-12-02

    Evaluation of the health related effects of beer intake is hampered by the lack of accurate tools for assessing intakes (biomarkers). Therefore, we identified plasma and urine metabolites associated with recent beer intake by untargeted metabolomics and established a characteristic metabolite pattern representing raw materials and beer production as a qualitative biomarker of beer intake. In a randomized, crossover, single-blinded meal study (MSt1), 18 participants were given, one at a time, four different test beverages: strong, regular, and nonalcoholic beers and a soft drink. Four participants were assigned to have two additional beers (MSt2). In addition to plasma and urine samples, test beverages, wort, and hops extract were analyzed by UPLC-QTOF. A unique metabolite pattern reflecting beer metabolome, including metabolites derived from beer raw material (i.e., N-methyl tyramine sulfate and the sum of iso-α-acids and tricyclohumols) and the production process (i.e., pyro-glutamyl proline and 2-ethyl malate), was selected to establish a compliance biomarker model for detection of beer intake based on MSt1. The model predicted the MSt2 samples collected before and up to 12 h after beer intake correctly (AUC = 1). A biomarker model including four metabolites representing both beer raw materials and production steps provided a specific and accurate tool for measurement of beer consumption.

  18. Unique features in the ARIES glovebox line

    International Nuclear Information System (INIS)

    Martinez, H.E.; Brown, W.G.; Flamm, B.; James, C.A.; Laskie, R.; Nelson, T.O.; Wedman, D.E.

    1998-01-01

    A series of unique features have been incorporated into the Advanced Recovery and Integrated Extraction System (ARIES) at the Los Alamos National Laboratory, TA-55 Plutonium Facility. The features enhance the material handling in the process of the dismantlement of nuclear weapon primaries in the glovebox line. Incorporated into these features are the various plutonium process module's different ventilation zone requirements that the material handling systems must meet. These features include a conveyor system that consists of a remotely controlled cart that transverses the length of the conveyor glovebox, can be operated from a remote location and can deliver process components to the entrance of any selected module glovebox. Within the modules there exists linear motion material handling systems with lifting hoist, which are controlled via an Allen Bradley control panel or local control panels. To remove the packaged products from the hot process line, the package is processed through an air lock/electrolytic decontamination process that removes the radioactive contamination from the outside of the package container and allows the package to be removed from the process line

  19. Clinical EPR: Unique Opportunities and Some Challenges

    Science.gov (United States)

    Swartz, Harold M.; Williams, Benjamin B.; Zaki, Bassem I.; Hartford, Alan C.; Jarvis, Lesley A.; Chen, Eunice; Comi, Richard J.; Ernstoff, Marc S.; Hou, Huagang; Khan, Nadeem; Swarts, Steven G.; Flood, Ann B.; Kuppusamy, Periannan

    2014-01-01

    Electron paramagnetic resonance (EPR) spectroscopy has been well established as a viable technique for measurement of free radicals and oxygen in biological systems, from in vitro cellular systems to in vivo small animal models of disease. However, the use of EPR in human subjects in the clinical setting, although attractive for a variety of important applications such as oxygen measurement, is challenged with several factors including the need for instrumentation customized for human subjects, probe and regulatory constraints. This paper describes the rationale and development of the first clinical EPR systems for two important clinical applications, namely, measurement of tissue oxygen (oximetry), and radiation dose (dosimetry) in humans. The clinical spectrometers operate at 1.2 GHz frequency and use surface loop resonators capable of providing topical measurements up to 1 cm depth in tissues. Tissue pO2 measurements can be carried out noninvasively and repeatedly after placement of an oxygen-sensitive paramagnetic material (currently India ink) at the site of interest. Our EPR dosimetry system is capable of measuring radiation-induced free radicals in the tooth of irradiated human subjects to determine the exposure dose. These developments offer potential opportunities for clinical dosimetry and oximetry, which include guiding therapy for individual patients with tumors or vascular disease, by monitoring of tissue oxygenation. Further work is in progress to translate this unique technology to routine clinical practice. PMID:24439333

  20. TDRSS S-shuttle unique receiver equipment

    Science.gov (United States)

    Weinberg, A.; Schwartz, J. J.; Spearing, R.

    1985-01-01

    Beginning with STS-9, the Tracking and Date Relay Satellite system (TDRSS) will start providing S- and Ku-band communications and tracking support to the Space Shuttle and its payloads. The most significant element of this support takes place at the TDRSS White Sands Ground Terminal, which processes the Shuttle return link S- and Ku-band signals. While Ku-band hardware available to other TDRSS users is also applied to Ku-Shuttle, stringent S-Shuttle link margins have precluded the application of the standard TDRSS S-band processing equipment to S-Shuttle. It was therfore found necessary to develop a unique S-Shuttle Receiver that embodies state-of-the-art digital technology and processing techniques. This receiver, developed by Motorola, Inc., enhances link margins by 1.5 dB relative to the standard S-band equipment and its bit error rate performance is within a few tenths of a dB of theory. An overview description of the Space Shuttle Receiver Equipment (SSRE) is presented which includes the presentation of block diagrams and salient design features. Selected, measured performance results are also presented.

  1. The AD: The unique anti-accelerator

    CERN Multimedia

    Slide show by Maximilien Brice. Voice (French only): Jacques Fichet. Content: Paola Catapano, Django Manglunki, CERN Bulletin

    2011-01-01

    Unlike other machines whose performance is measured in terms of energy records, AD's uniqueness resides in the fact that it can very effectively decelerate beams. At the hearth of antimatter production at CERN, the AD is making headlines in the world's press. This provides an excellent opportunity for us to retrace its history in images.   var flash_video_player=get_video_player_path(); insert_player_for_external('Video/Public/Movies/2011/CERN-MOVIE-2011-083/CERN-MOVIE-2011-083-0753-kbps-480x360-25-fps-audio-64-kbps-44-kHz-stereo', 'mms://mediastream.cern.ch/MediaArchive/Video/Public/Movies/2011/CERN-MOVIE-2011-083/CERN-MOVIE-2011-083-0480-kbps-384x288-25-fps-audio-128-kbps-48-kHz-stereo.wmv', 'false', 480, 360, 'http://mediaarchive.cern.ch/MediaArchive/Video/Public/Movies/2011/CERN-MOVIE-2011-083/CERN-MOVIE-2011-083-posterframe-480x360-at-5-percent.jpg', '1357551', true, '');  

  2. Hausdorff dimension of unique beta expansions

    International Nuclear Information System (INIS)

    Kong, Derong; Li, Wenxia

    2015-01-01

    Given an integer N ⩾ 2 and a real number β > 1, let Γ β, N be the set of all x=∑ i=1 ∞ d i /β i with d i  ∈ {0, 1, ···, N − 1} for all i ⩾ 1. The infinite sequence (d i ) is called a β-expansion of x. Let U β,N be the set of all x's in Γ β,N which have unique β-expansions. We give explicit formula of the Hausdorff dimension of U β,N for β in any admissible interval [β L , β U ], where β L is a purely Parry number while β U is a transcendental number whose quasi-greedy expansion of 1 is related to the classical Thue–Morse sequence. This allows us to calculate the Hausdorff dimension of U β,N for almost every β > 1. In particular, this improves the main results of Gábor Kallós (1999, 2001). Moreover, we find that the dimension function f(β) = dim H U β,N fluctuates frequently for β ∈ (1, N). (paper)

  3. Unique type of isolated cardiac valvular amyloidosis

    Directory of Open Access Journals (Sweden)

    Reehana Salma

    2006-10-01

    Full Text Available Abstract Background Amyloid deposition in heart is a common occurrence in systemic amyloidosis. But localised valvular amyloid deposits are very uncommon. It was only in 1922 that the cases of valvular amyloidosis were reported. Then in 1980, Goffin et al reported another type of valvular amyloidosis, which he called the dystrophic valvular amyloidosis. We report a case of aortic valve amyloidosis which is different from the yet described valvular amyloidosis. Case presentation A 72 years old gentleman underwent urgent aortic valve replacement. Intraoperatively, a lesion was found attached to the inferior surface of his bicuspid aortic valve. Histopathology examination of the valve revealed that the lesion contained amyloid deposits, identified as AL amyloidosis. The serum amyloid A protein (SAP scan was normal and showed no evidence of systemic amyloidosis. The ECG and echocardiogram were not consistent with cardiac amyloidosis. Conclusion Two major types of cardiac amyloidosis have been described in literature: primary-myelomatous type (occurs with systemic amyolidosis, and senile type(s. Recently, a localised cardiac dystrophic valvular amyloidosis has been described. In all previously reported cases, there was a strong association of localised valvular amyloidosis with calcific deposits. Ours is a unique case which differs from the previously reported cases of localised valvular amyloidosis. In this case, the lesion was not associated with any scar tissue. Also there was no calcific deposit found. This may well be a yet unknown type of isolated valvular amyloidosis.

  4. A Unique Civil Engineering Capstone Design Course

    Directory of Open Access Journals (Sweden)

    G Padmanabhan

    2018-02-01

    Full Text Available The North Dakota State University, USA, capstone course was developed as a unique model in response to the effort of the Accreditation Board of Engineering and Technology, USA, to streamline and improve design instruction in the curriculum and has steadily evolved to keep pace with the ever-changing technology and the expectations of the profession and the society we serve. A capstone design course by definition should be a design experience for students in the final year before graduation integrating all major design concepts they have learned up until then in the program. Carefully chosen real world projects with design content in all sub-disciplines of civil engineering are assigned in this team-taught course. Faculty and practicing professionals make presentations on design process; project management; leadership in an engineering environment; and public policy; global perspectives in engineering; and professional career and licensure. Practicing professionals also critique the final student presentations. Students work in teams with number of faculty serving as technical consultants, and a faculty mentor for each team to provide non-technical guidance and direction. The course requires students to demonstrate mastery of the curriculum and to work with others in a team environment. Course assessment includes evaluation of the final design, presentations, written technical reports, project design schedule, a project design journal, and reaction papers.

  5. Unique thermal record in False Bay

    CSIR Research Space (South Africa)

    Grundlingh, ML

    1993-10-01

    Full Text Available Over the past decade False Bay has assumed a prime position in terms of research in to large South African bays. This is manifested by investigations that cover flow conditions modelling, thermal structure, management, biology and nutrients, geology...

  6. ZEEMAN DOPPLER MAPS: ALWAYS UNIQUE, NEVER SPURIOUS?

    Energy Technology Data Exchange (ETDEWEB)

    Stift, Martin J.; Leone, Francesco [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom)

    2017-01-01

    Numerical models of atomic diffusion in magnetic atmospheres of ApBp stars predict abundance structures that differ from the empirical maps derived with (Zeeman) Doppler mapping (ZDM). An in-depth analysis of this apparent disagreement investigates the detectability by means of ZDM of a variety of abundance structures, including (warped) rings predicted by theory, but also complex spot-like structures. Even when spectra of high signal-to-noise ratio are available, it can prove difficult or altogether impossible to correctly recover shapes, positions, and abundances of a mere handful of spots, notwithstanding the use of all four Stokes parameters and an exactly known field geometry; the recovery of (warped) rings can be equally challenging. Inversions of complex abundance maps that are based on just one or two spectral lines usually permit multiple solutions. It turns out that it can by no means be guaranteed that any of the regularization functions in general use for ZDM (maximum entropy or Tikhonov) will lead to a true abundance map instead of some spurious one. Attention is drawn to the need for a study that would elucidate the relation between the stratified, field-dependent abundance structures predicted by diffusion theory on the one hand, and empirical maps obtained by means of “canonical” ZDM, i.e., with mean atmospheres and unstratified abundances, on the other hand. Finally, we point out difficulties arising from the three-dimensional nature of the atomic diffusion process in magnetic ApBp star atmospheres.

  7. Lourdes: A uniquely Catholic approach to medicine.

    Science.gov (United States)

    Dichoso, Travis Jon

    2015-02-01

    As an American medical student, I spent the summer break between my first and second year in Lourdes, France, the site where the Immaculate Conception appeared eighteen times to St. Bernadette in 1858 as proclaimed approved by the Catholic Church and whose water is associated with over seven thousand unexplained cures. During this time I volunteered with St. Joseph's Service and Poste Secour, followed several medical teams taking care of large pilgrim groups, and shadowed Dr. Alessandro de Franciscis the president of Le Bureau des Constations Médicales, the office in Lourdes charged with investigating claims of miracles. Through my experiences, I found the mission of medicine in Lourdes to be twofold: to provide the critical care needed to give sick persons the chance to transform their experience of disease through their faith; and secondly, through the efforts of the Medical Bureau, to be an instrument by which we can comprehend the wonders of the work of God. I conclude that this twofold mission should inform the work of every Catholic in health care or research, and Lourdes provides the venue par excellence to cultivate this mission. Lay Summary: Lourdes is a pilgrimage site in southern France that has been associated with medical miracles for the past 150 years. The site is unique in that throughout its history, physicians, of any or no faith, have been invited to participate in the proceedings of the investigations of each claimed cure. The investigations have formalized into a process handled by the Lourdes Medical Bureau and the Lourdes International Medical Association. Travis Dichoso, an American medical student, writes about his experiences as part of this process.

  8. Evolution of a Unique Systems Engineering Capability

    Energy Technology Data Exchange (ETDEWEB)

    Robert M. Caliva; James A. Murphy; Kyle B. Oswald

    2011-06-01

    The Idaho National Laboratory (INL) is a science-based, applied engineering laboratory dedicated to supporting U.S. Department of Energy missions in nuclear and energy research, science, and national security. The INL’s Systems Engineering organization supports all of the various programs under this wide array of missions. As with any multifaceted organization, strategic planning is essential to establishing a consistent culture and a value discipline throughout all levels of the enterprise. While an organization can pursue operational excellence, product leadership or customer intimacy, it is extremely difficult to excel or achieve best-in-class at all three. In fact, trying to do so has resulted in the demise of a number of organizations given the very intricate balancing act that is necessary. The INL’s Systems Engineering Department has chosen to focus on customer intimacy where the customer’s needs are first and foremost and a more total solution is the goal. Frequently a total solution requires the employment of specialized tools to manage system complexity. However, it is only after understanding customer needs that tool selection and use would be pursued. This results in using both commercial-off-the-shelf (COTS) tools and, in some cases, requires internal development of specialized tools. This paper describes how a unique systems engineering capability, through the development of customized tools, evolved as a result of this customer-focused culture. It also addresses the need for a common information model or analysis framework and presents an overview of the tools developed to manage and display relationships between entities, support trade studies through the application of utility theory, and facilitate the development of a technology roadmap to manage system risk and uncertainty.

  9. Core and Shell Song Systems Unique to the Parrot Brain

    Science.gov (United States)

    Chakraborty, Mukta; Walløe, Solveig; Nedergaard, Signe; Fridel, Emma E.; Dabelsteen, Torben; Pakkenberg, Bente; Bertelsen, Mads F.; Dorrestein, Gerry M.; Brauth, Steven E.; Durand, Sarah E.; Jarvis, Erich D.

    2015-01-01

    The ability to imitate complex sounds is rare, and among birds has been found only in parrots, songbirds, and hummingbirds. Parrots exhibit the most advanced vocal mimicry among non-human animals. A few studies have noted differences in connectivity, brain position and shape in the vocal learning systems of parrots relative to songbirds and hummingbirds. However, only one parrot species, the budgerigar, has been examined and no differences in the presence of song system structures were found with other avian vocal learners. Motivated by questions of whether there are important differences in the vocal systems of parrots relative to other vocal learners, we used specialized constitutive gene expression, singing-driven gene expression, and neural connectivity tracing experiments to further characterize the song system of budgerigars and/or other parrots. We found that the parrot brain uniquely contains a song system within a song system. The parrot “core” song system is similar to the song systems of songbirds and hummingbirds, whereas the “shell” song system is unique to parrots. The core with only rudimentary shell regions were found in the New Zealand kea, representing one of the only living species at a basal divergence with all other parrots, implying that parrots evolved vocal learning systems at least 29 million years ago. Relative size differences in the core and shell regions occur among species, which we suggest could be related to species differences in vocal and cognitive abilities. PMID:26107173

  10. Unique Construction and Social Experiences in Residential Remediation Sites - 13423

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Paul; Scarborough, Rebecca [Sevenson Environmental Services, Inc. 2749 Lockport Road, Niagara Falls, NY 14305 (United States)

    2013-07-01

    Sevenson Environmental Services, Inc., (Sevenson) has performed several radiological remediation projects located in residential urban areas. Over the course of these projects, there has been a wide variety of experiences encountered from construction related issues to unique social situations. Some of the construction related issues included the remediation of interior basements where contaminated material was located under the footers of the structure or was used in the mortar between cinder block or field stone foundations. Other issues included site security, maintaining furnaces or other utilities, underpinning, backfilling and restoration. In addition to the radiological hazards associated with this work there were occupational safety and industrial hygiene issues that had to be addressed to ensure the safety and health of neighboring properties and residents. The unique social situations at these job sites have included arson, theft/stolen property, assault/battery, prostitution, execution of arrest warrants for residents, discovery of drugs and paraphernalia, blood borne pathogens, and unexploded ordnance. Some of these situations have become a sort of comical urban legend throughout the organization. One situation had historical significance, involving the demolition of a house to save a tree older than the Declaration of Independence. All of these projects typically involve the excavation of early 20. century items such as advertisement signs, various old bottles (milk, Listerine, perfume, whisky) and other miscellaneous common trash items. (authors)

  11. Rationality, irrationality and escalating behavior in lowest unique bid auctions.

    Science.gov (United States)

    Radicchi, Filippo; Baronchelli, Andrea; Amaral, Luís A N

    2012-01-01

    Information technology has revolutionized the traditional structure of markets. The removal of geographical and time constraints has fostered the growth of online auction markets, which now include millions of economic agents worldwide and annual transaction volumes in the billions of dollars. Here, we analyze bid histories of a little studied type of online auctions--lowest unique bid auctions. Similarly to what has been reported for foraging animals searching for scarce food, we find that agents adopt Lévy flight search strategies in their exploration of "bid space". The Lévy regime, which is characterized by a power-law decaying probability distribution of step lengths, holds over nearly three orders of magnitude. We develop a quantitative model for lowest unique bid online auctions that reveals that agents use nearly optimal bidding strategies. However, agents participating in these auctions do not optimize their financial gain. Indeed, as long as there are many auction participants, a rational profit optimizing agent would choose not to participate in these auction markets.

  12. Dissociative absorption: An empirically unique, clinically relevant, dissociative factor.

    Science.gov (United States)

    Soffer-Dudek, Nirit; Lassri, Dana; Soffer-Dudek, Nir; Shahar, Golan

    2015-11-01

    Research of dissociative absorption has raised two questions: (a) Is absorption a unique dissociative factor within a three-factor structure, or a part of one general dissociative factor? Even when three factors are found, the specificity of the absorption factor is questionable. (b) Is absorption implicated in psychopathology? Although commonly viewed as "non-clinical" dissociation, absorption was recently hypothesized to be specifically associated with obsessive-compulsive symptoms. To address these questions, we conducted exploratory and confirmatory factor analyses on 679 undergraduates. Analyses supported the three-factor model, and a "purified" absorption scale was extracted from the original inclusive absorption factor. The purified scale predicted several psychopathology scales. As hypothesized, absorption was a stronger predictor of obsessive-compulsive symptoms than of general psychopathology. In addition, absorption was the only dissociative scale that longitudinally predicted obsessive-compulsive symptoms. We conclude that absorption is a unique and clinically relevant dissociative tendency that is particularly meaningful to obsessive-compulsive symptoms. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Uniqueness of magnetotomography for fuel cells and fuel cell stacks

    International Nuclear Information System (INIS)

    Lustfeld, H; Hirschfeld, J; Reissel, M; Steffen, B

    2009-01-01

    The criterion for the applicability of any tomographic method is its ability to construct the desired inner structure of a system from external measurements, i.e. to solve the inverse problem. Magnetotomography applied to fuel cells and fuel cell stacks aims at determining the inner current densities from measurements of the external magnetic field. This is an interesting idea since in those systems the inner electric current densities are large, several hundred mA per cm 2 and therefore relatively high external magnetic fields can be expected. Still the question remains how uniquely the inverse problem can be solved. Here we present a proof that by exploiting Maxwell's equations extensively the inverse problem of magnetotomography becomes unique under rather mild assumptions and we show that these assumptions are fulfilled in fuel cells and fuel cell stacks. Moreover, our proof holds true for any other device fulfilling the assumptions listed here. Admittedly, our proof has one caveat: it does not contain an estimate of the precision requirements the measurements need to fulfil for enabling reconstruction of the inner current densities from external magnetic fields.

  14. Rationality, irrationality and escalating behavior in lowest unique bid auctions.

    Directory of Open Access Journals (Sweden)

    Filippo Radicchi

    Full Text Available Information technology has revolutionized the traditional structure of markets. The removal of geographical and time constraints has fostered the growth of online auction markets, which now include millions of economic agents worldwide and annual transaction volumes in the billions of dollars. Here, we analyze bid histories of a little studied type of online auctions--lowest unique bid auctions. Similarly to what has been reported for foraging animals searching for scarce food, we find that agents adopt Lévy flight search strategies in their exploration of "bid space". The Lévy regime, which is characterized by a power-law decaying probability distribution of step lengths, holds over nearly three orders of magnitude. We develop a quantitative model for lowest unique bid online auctions that reveals that agents use nearly optimal bidding strategies. However, agents participating in these auctions do not optimize their financial gain. Indeed, as long as there are many auction participants, a rational profit optimizing agent would choose not to participate in these auction markets.

  15. Unique Construction and Social Experiences in Residential Remediation Sites - 13423

    International Nuclear Information System (INIS)

    Jung, Paul; Scarborough, Rebecca

    2013-01-01

    Sevenson Environmental Services, Inc., (Sevenson) has performed several radiological remediation projects located in residential urban areas. Over the course of these projects, there has been a wide variety of experiences encountered from construction related issues to unique social situations. Some of the construction related issues included the remediation of interior basements where contaminated material was located under the footers of the structure or was used in the mortar between cinder block or field stone foundations. Other issues included site security, maintaining furnaces or other utilities, underpinning, backfilling and restoration. In addition to the radiological hazards associated with this work there were occupational safety and industrial hygiene issues that had to be addressed to ensure the safety and health of neighboring properties and residents. The unique social situations at these job sites have included arson, theft/stolen property, assault/battery, prostitution, execution of arrest warrants for residents, discovery of drugs and paraphernalia, blood borne pathogens, and unexploded ordnance. Some of these situations have become a sort of comical urban legend throughout the organization. One situation had historical significance, involving the demolition of a house to save a tree older than the Declaration of Independence. All of these projects typically involve the excavation of early 20. century items such as advertisement signs, various old bottles (milk, Listerine, perfume, whisky) and other miscellaneous common trash items. (authors)

  16. Rationality, Irrationality and Escalating Behavior in Lowest Unique Bid Auctions

    Science.gov (United States)

    Radicchi, Filippo; Baronchelli, Andrea; Amaral, Luís A. N.

    2012-01-01

    Information technology has revolutionized the traditional structure of markets. The removal of geographical and time constraints has fostered the growth of online auction markets, which now include millions of economic agents worldwide and annual transaction volumes in the billions of dollars. Here, we analyze bid histories of a little studied type of online auctions – lowest unique bid auctions. Similarly to what has been reported for foraging animals searching for scarce food, we find that agents adopt Lévy flight search strategies in their exploration of “bid space”. The Lévy regime, which is characterized by a power-law decaying probability distribution of step lengths, holds over nearly three orders of magnitude. We develop a quantitative model for lowest unique bid online auctions that reveals that agents use nearly optimal bidding strategies. However, agents participating in these auctions do not optimize their financial gain. Indeed, as long as there are many auction participants, a rational profit optimizing agent would choose not to participate in these auction markets. PMID:22279553

  17. Creativity and technical innovation: spatial ability's unique role.

    Science.gov (United States)

    Kell, Harrison J; Lubinski, David; Benbow, Camilla P; Steiger, James H

    2013-09-01

    In the late 1970s, 563 intellectually talented 13-year-olds (identified by the SAT as in the top 0.5% of ability) were assessed on spatial ability. More than 30 years later, the present study evaluated whether spatial ability provided incremental validity (beyond the SAT's mathematical and verbal reasoning subtests) for differentially predicting which of these individuals had patents and three classes of refereed publications. A two-step discriminant-function analysis revealed that the SAT subtests jointly accounted for 10.8% of the variance among these outcomes (p development of creativity, beyond the roles played by the abilities traditionally measured in educational selection, counseling, and industrial-organizational psychology. Spatial ability plays a key and unique role in structuring many important psychological phenomena and should be examined more broadly across the applied and basic psychological sciences.

  18. Human Uniqueness, Cognition by Description, and Procedural Memory

    Directory of Open Access Journals (Sweden)

    John Bolender

    2008-06-01

    Full Text Available Evidence will be reviewed suggesting a fairly direct link between the human ability to think about entities which one has never perceived — here called “cognition by description” — and procedural memory. Cognition by description is a uniquely hominid trait which makes religion, science, and history possible. It is hypothesized that cognition by description (in the manner of Bertrand Russell’s “knowledge by description” requires variable binding, which in turn utilizes quantifier raising. Quantifier raising plausibly depends upon the computational core of language, specifically the element of it which Noam Chomsky calls “internal Merge”. Internal Merge produces hierarchical structures by means of a memory of derivational steps, a process plausibly involving procedural memory. The hypothesis is testable, predicting that procedural memory deficits will be accompanied by impairments in cognition by description. We also discuss neural mechanisms plausibly underlying procedural memory and also, by our hypothesis, cognition by description.

  19. Embodied history. Uniqueness and exemplarity of South African AIDS.

    Science.gov (United States)

    Fassin, Didier

    2002-01-01

    The exceptionality of AIDS in South Africa, both for its epidemiological features and public controversies, seems to have its correspondence in the exceptionalism of South African history, with its unprecedented regime of apartheid and its unexpected turn to democracy. The article shows that AIDS in this country can simultaneously be seen as unique (because of the historical context in which it is inscribed) and exemplar (of social determinants observed in other countries characterised by similar past or present of domination). As an alternative to cultural and behavioural models of the epidemic which have been widely spread on the African continent, the concept of embodiment of history is proposed in order to account for both the structural facts underlying the epidemic (inequality, violence, migration) and the construction of collective as well as individual narratives of the disease (including victimisation and accusation).

  20. Kerala: a unique model of development.

    Science.gov (United States)

    Kannan, K P; Thankappan, K R; Ramankutty, V; Aravindan, K P

    1991-12-01

    This article capsules health in terms of morbidity, mortality, and maternal and child health; sex ratios, and population density in Kerala state in India from a more expanded report. Kerala state is known for its highly literate and female literate, and poor income population, but its well advanced state of demographic transition. There is a declining population growth rate, a high average marriage age, a low fertility rate, and a high degree of population mobility. One of the unique features of Kerala is the high female literacy, and the favorable position of women in decision making and a matrilineal inheritance mode. The rights of the poor and underprivileged have been upheld. The largest part of government revenue is spent on education followed by health. Traditional healing systems such the ayurveda are strong in Kerala, and Christian missionaries have contributed to a caring tradition. Morbidity is high and mortality is low because medical interventions have affected morality only. The reduction of poverty and environmentally related diseases has not been accomplished inspite of land reform, mass schooling, and general egalitarian policies. Mortality declines and a decline in birth rates have lead to a more adult and aged population, which increases the prevalence of chronic degenerative diseases. Historically, the death rate in Kerala was always lower (25/1000 in 1930 and 6.4 in 1986). The gains in mortality were made in reducing infant mortality (27/1000), which is 4 times less than India as a whole and comparable to Korea, Panama, Yugoslavia, Sri Lanka, and Colombia. Lower female mortality occurs in the 0-4 years. Life expectancy which was the same as India's in 1930 is currently 12 years higher than India's. Females have a higher expectation of life. The sex ratio in 1981 was 1032 compared to India's of 935. Kerala had almost replacement level in 1985. The crude birth rate is 21 versus 32 for India. In addition to the decline in death rates of those 5

  1. Unitary Evolution as a Uniqueness Criterion

    Science.gov (United States)

    Cortez, J.; Mena Marugán, G. A.; Olmedo, J.; Velhinho, J. M.

    2015-01-01

    It is well known that the process of quantizing field theories is plagued with ambiguities. First, there is ambiguity in the choice of basic variables describing the system. Second, once a choice of field variables has been made, there is ambiguity concerning the selection of a quantum representation of the corresponding canonical commutation relations. The natural strategy to remove these ambiguities is to demand positivity of energy and to invoke symmetries, namely by requiring that classical symmetries become unitarily implemented in the quantum realm. The success of this strategy depends, however, on the existence of a sufficiently large group of symmetries, usually including time-translation invariance. These criteria are therefore generally insufficient in non-stationary situations, as is typical for free fields in curved spacetimes. Recently, the criterion of unitary implementation of the dynamics has been proposed in order to select a unique quantization in the context of manifestly non-stationary systems. Specifically, the unitarity criterion, together with the requirement of invariance under spatial symmetries, has been successfully employed to remove the ambiguities in the quantization of linearly polarized Gowdy models as well as in the quantization of a scalar field with time varying mass, propagating in a static background whose spatial topology is either of a d-sphere (with d = 1, 2, 3) or a three torus. Following Ref. 3, we will see here that the symmetry and unitarity criteria allows for a complete removal of the ambiguities in the quantization of scalar fields propagating in static spacetimes with compact spatial sections, obeying field equations with an explicitly time-dependent mass, of the form ddot φ - Δ φ + s(t)φ = 0 . These results apply in particular to free fields in spacetimes which, like e.g. in the closed FRW models, are conformal to a static spacetime, by means of an exclusively time-dependent conformal factor. In fact, in such

  2. Nature inspired capacitive sensor with unique and unclonable characteristic

    Science.gov (United States)

    Karuthedath, C. B.; Schwesinger, N.

    2018-02-01

    Background of this paper is the development of sensors showing a nature like characteristic. The sensor is able to detect excitations on inertia bases and operates capacitive. It consists of a miniaturized interdigitated electrode structure on a printed circuit board, a flexible and conductive membrane of PDMS located in a certain distance above and a certain number of steel balls fixed on top of the membrane. The steel ball distribution is random and the conductivity of the membrane is not homogeneous across the membrane. Due to this double random distribution, no sensor equals the other, although the external geometry is equal. The overall size of the sensor is 4.7mm x 4.7mm x 1.7mm. Tilt, acceleration or magnetic fields are capable of causing forces on the steel balls and therefore relative movements between the membrane and the electrode structures. Due to this movement, capacity changes of the arrangement are measurable. This paper describes besides the fabrication of conductive membranes the preparation of regarding sensors. Process technology makes cloning of the sensors impossible. Although all process steps are suited for mass production, no sensor equals the other. Measurements with these sensors prove that each sensor reacts differently to the same excitation. Calculations of the Intra-Concordance-Coefficient show the similarity of the sensors for equal excitations. On the other hand, the maximum Inter-Concordance-Coefficient reveals the differences of such sensors very clearly. Such a characteristic, i.e. equal reaction to equal excitation and an output of significantly different signals allows considering each sensor as a unique device. The sensors obviously behave like receptors in natural organisms. These unusual properties of uniqueness and impossibility to clone make the sensors very interesting for highly secure identification demands. In combination with a very simple measurement procedure, the sensors are an attractive hardware base for

  3. ROSAT Discovers Unique, Distant Cluster of Galaxies

    Science.gov (United States)

    1995-06-01

    Brightest X-ray Cluster Acts as Strong Gravitational Lens Based on exciting new data obtained with the ROSAT X-ray satellite and a ground-based telescope at the ESO La Silla Observatory, a team of European astronomers [2] has just discovered a very distant cluster of galaxies with unique properties. It emits the strongest X-ray emission of any cluster ever observed by ROSAT and is accompanied by two extraordinarily luminous arcs that represent the gravitationally deflected images of even more distant objects. The combination of these unusual characteristics makes this cluster, now known as RXJ1347.5-1145, a most interesting object for further cosmological studies. DISCOVERY AND FOLLOW-UP OBSERVATIONS This strange cluster of galaxies was discovered during the All Sky Survey with the ROSAT X-ray satellite as a moderately intense X-ray source in the constellation of Virgo. It could not be identified with any already known object and additional ground-based observations were therefore soon after performed with the Max-Planck-Society/ESO 2.2-metre telescope at the La Silla observatory in Chile. These observations took place within a large--scale redshift survey of X-ray clusters of galaxies detected by the ROSAT All Sky Survey, a so-called ``ESO Key Programme'' led by astronomers from the Max-Planck-Institut fur Extraterrestrische Physik and the Osservatorio Astronomico di Brera. The main aim of this programme is to identify cluster X-ray sources, to determine the distance to the X-ray emitting clusters and to investigate their overall properties. These observations permitted to measure the redshift of the RXJ1347.5-1145 cluster as z = 0.45, i.e. it moves away from us with a velocity (about 106,000 km/sec) equal to about one-third of the velocity of light. This is an effect of the general expansion of the universe and it allows to determine the distance as about 5,000 million light-years (assuming a Hubble constant of 75 km/sec/Mpc). In other words, we see these

  4. Novel criteria of uniqueness for signal reconstruction from phase

    NARCIS (Netherlands)

    Ma, C.

    1991-01-01

    An approach for ascertaining whether a signal is uniquely determined by its Fourier transform phase is proposed. It is shown that uniqueness corresponds to the nonsingularity of a matrix which can be formed from the finite-length real sequence. The criterion of uniqueness for reconstructing a

  5. Symmetry breaking and uniqueness for the incompressible Navier-Stokes equations

    International Nuclear Information System (INIS)

    Dascaliuc, Radu; Thomann, Enrique; Waymire, Edward C.; Michalowski, Nicholas

    2015-01-01

    The present article establishes connections between the structure of the deterministic Navier-Stokes equations and the structure of (similarity) equations that govern self-similar solutions as expected values of certain naturally associated stochastic cascades. A principle result is that explosion criteria for the stochastic cascades involved in the probabilistic representations of solutions to the respective equations coincide. While the uniqueness problem itself remains unresolved, these connections provide interesting problems and possible methods for investigating symmetry breaking and the uniqueness problem for Navier-Stokes equations. In particular, new branching Markov chains, including a dilogarithmic branching random walk on the multiplicative group (0, ∞), naturally arise as a result of this investigation

  6. Symmetry breaking and uniqueness for the incompressible Navier-Stokes equations.

    Science.gov (United States)

    Dascaliuc, Radu; Michalowski, Nicholas; Thomann, Enrique; Waymire, Edward C

    2015-07-01

    The present article establishes connections between the structure of the deterministic Navier-Stokes equations and the structure of (similarity) equations that govern self-similar solutions as expected values of certain naturally associated stochastic cascades. A principle result is that explosion criteria for the stochastic cascades involved in the probabilistic representations of solutions to the respective equations coincide. While the uniqueness problem itself remains unresolved, these connections provide interesting problems and possible methods for investigating symmetry breaking and the uniqueness problem for Navier-Stokes equations. In particular, new branching Markov chains, including a dilogarithmic branching random walk on the multiplicative group (0, ∞), naturally arise as a result of this investigation.

  7. What is Unique About Extension Personnel in the City?

    Directory of Open Access Journals (Sweden)

    Julie Fox

    2017-06-01

    Full Text Available Extension’s pursuit to better attract, develop, retain, and structure competent personnel in the city requires new strategies to build on the knowledge base established through previous research and practice. With the support of numerous national organizations, this study utilized a Competency Framework Development (CFD process to systematically tap into the knowledge of County Extension Directors serving in large urban communities. Findings indicated these local leaders need specific knowledge, skills, attitudes, and beliefs that are both similar and unique when compared with results from other Extension competency studies. Competencies identified included building social and financial capital, strategic planning and organizing, resource attraction and management, advocacy and impact accountability with multiple stakeholders, and others. A primary difference was that diversity, complexity, and scale in urban communities influenced the extent to which competencies are demonstrated. Research results can be applied to a competency model that incorporates intentional recruiting and hiring practices that reflect the diversity and priorities of the community, competency-based professional development, competitive compensation and retention tactics, and staffing structure and strategies. Further research can include CFD with various types of Extension personnel and perspectives. Extension leaders can continue learning alongside others who can help inform administrators about human capital policies and practices.

  8. Unique biochemical and mineral composition of whale ear bones.

    Science.gov (United States)

    Kim, Sora L; Thewissen, J G M; Churchill, Morgan M; Suydam, Robert S; Ketten, Darlene R; Clementz, Mark T

    2014-01-01

    Abstract Cetaceans are obligate aquatic mammals derived from terrestrial artiodactyls. The defining characteristic of cetaceans is a thick and dense lip (pachyosteosclerotic involucrum) of an ear bone (the tympanic). This unique feature is absent in modern terrestrial artiodactyls and is suggested to be important in underwater hearing. Here, we investigate the mineralogical and biochemical properties of the involucrum, as these may hold clues to the aquatic adaptations of cetaceans. We compared bioapatites (enamel, dentine, cementum, and skeletal bone) of cetaceans with those of terrestrial artiodactyls and pachyosteosclerotic ribs of manatees (Sirenia). We investigated organic, carbonate, and mineral composition as well as crystal size and crystallinity index. In all studied variables, bioapatites of the cetacean involucrum were intermediate in composition and structure between those of tooth enamel on the one hand and those of dentine, cementum, and skeletal bone on the other. We also studied the amino acid composition of the cetacean involucrum relative to that of other skeletal bone. The central involucrum had low glycine and hydroxyproline concentrations but high concentrations of nonessential amino acids, unlike most bone samples but similar to the tympanic of hippos and the (pachyosteosclerotic) ribs of manatees. These amino acid results are evidence of rapid bone development. We hypothesize that the mineralogical and amino acid composition of cetacean bullae differs from that of other bone because of (1) functional modifications for underwater sound reception and (2) structural adaptations related to rapid ossification.

  9. A uniquely specialized ear in a very early tetrapod.

    Science.gov (United States)

    Clack, J A; Ahlberg, P E; Finney, S M; Dominguez Alonso, P; Robinson, J; Ketcham, R A

    2003-09-04

    The Late Devonian genus Ichthyostega was for many decades the earliest known tetrapod, and the sole representative of a transitional form between a fish and a land vertebrate. However, despite being known since 1932 (ref. 1) from a large collection of specimens, its morphology remained enigmatic and not what was expected of a very primitive tetrapod. Its apparent specializations led it to be considered as a "blind offshoot" or "sidebranch" off the tetrapod family tree, and recent cladistic analyses have disagreed about its exact phylogenetic position within the tetrapod stem group. In particular, its braincase and ear region defied interpretation, such that conventional anatomical terms seemed inapplicable. Using new material collected in 1998 (ref. 9), preparation of earlier-collected material, and high-resolution computed tomography scanning, here we identify and interpret these problematic anatomical structures. They can now be seen to form part of a highly specialized ear, probably a hearing device for use in water. This represents a structurally and functionally unique modification of the tetrapod otic region, unlike anything seen in subsequent tetrapod evolution. The presence of deeply grooved gill bars as in its contemporary Acanthostega suggest that Ichthyostega may have been more aquatically adapted than previously believed.

  10. Mast Cells Produce a Unique Chondroitin Sulfate Epitope.

    Science.gov (United States)

    Farrugia, Brooke L; Whitelock, John M; O'Grady, Robert; Caterson, Bruce; Lord, Megan S

    2016-02-01

    The granules of mast cells contain a myriad of mediators that are stored and protected by the sulfated glycosaminoglycan (GAG) chains that decorate proteoglycans. Whereas heparin is the GAG predominantly associated with mast cells, mast cell proteoglycans are also decorated with heparan sulfate and chondroitin sulfate (CS). This study investigated a unique CS structure produced by mast cells that was detected with the antibody clone 2B6 in the absence of chondroitinase ABC digestion. Mast cells in rodent tissue sections were characterized using toluidine blue, Leder stain and the presence of mast cell tryptase. The novel CS epitope was identified in rodent tissue sections and localized to cells that were morphologically similar to cells chemically identified as mast cells. The rodent mast cell-like line RBL-2H3 was also shown to express the novel CS epitope. This epitope co-localized with multiple CS proteoglycans in both rodent tissue and RBL-2H3 cultured cells. These findings suggest that the novel CS epitope that decorates mast cell proteoglycans may play a role in the way these chains are structured in mast cells. © 2016 The Histochemical Society.

  11. IDGenerator: unique identifier generator for epidemiologic or clinical studies

    Directory of Open Access Journals (Sweden)

    Matthias Olden

    2016-09-01

    Full Text Available Abstract Background Creating study identifiers and assigning them to study participants is an important feature in epidemiologic studies, ensuring the consistency and privacy of the study data. The numbering system for identifiers needs to be random within certain number constraints, to carry extensions coding for organizational information, or to contain multiple layers of numbers per participant to diversify data access. Available software can generate globally-unique identifiers, but identifier-creating tools meeting the special needs of epidemiological studies are lacking. We have thus set out to develop a software program to generate IDs for epidemiological or clinical studies. Results Our software IDGenerator creates unique identifiers that not only carry a random identifier for a study participant, but also support the creation of structured IDs, where organizational information is coded into the ID directly. This may include study center (for multicenter-studies, study track (for studies with diversified study programs, or study visit (baseline, follow-up, regularly repeated visits. Our software can be used to add a check digit to the ID to minimize data entry errors. It facilitates the generation of IDs in batches and the creation of layered IDs (personal data ID, study data ID, temporary ID, external data ID to ensure a high standard of data privacy. The software is supported by a user-friendly graphic interface that enables the generation of IDs in both standard text and barcode 128B format. Conclusion Our software IDGenerator can create identifiers meeting the specific needs for epidemiologic or clinical studies to facilitate study organization and data privacy. IDGenerator is freeware under the GNU General Public License version 3; a Windows port and the source code can be downloaded at the Open Science Framework website: https://osf.io/urs2g/ .

  12. MYRRHA. An innovative and unique research facility

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Rafaeol; Neerdael, Bernard; Schyns, Marc; Dyck, Steven Van; Michiels, Sidney; Ait Abderrahim, Hamid, E-mail: myrrha@sckcen.be [Belgian Nuclear Research Centre (SCK-CEN), Mol (Belgium)

    2012-03-15

    The MYRRHA project started in 1998 by SCK{center_dot}CEN in collaboration with Ion Beam Applications (IBA, Louvain-la-Neuve), as an upgrade of the ADONIS project. MYRRHA is designed as a multi-purpose irradiation facility in order to support research programmes on fission and fusion reactor structural materials and nuclear fuel development. Applications of these are found in Accelerator Driven Systems (ADS) systems and in present generation as well as in next generation critical reactors. The first objective of MYRRHA however, will be to demonstrate on one hand the ADS concept at a reasonable power level and on the other hand the technological feasibility of transmutation of Minor Actinides (MA) and Long-Lived Fission Products (LLFP) arising from the reprocessing of radioactive waste. MYRRHA will also help the development of the Pb-alloys technology needed for the LFR (Lead Fast Reactor) Gen.IV concept. Transmutation of MA can be completed in an efficient way in fast neutron spectrum facilities. Both critical reactors and sub-critical ADS are potential candidates as dedicated transmutation systems. However, critical reactors, heavily loaded with fuel containing large amounts of MA, pose safety problems caused by unfavourable reactivity coefficients due to the little delayed neutron fraction. A sub-critical ADS operates in a flexible and safe manner even with a core loading containing a high amount of MA leading to achieve a high efficient transmutation. Thus, the sub-criticality is not a virtue but rather a necessity for an efficient and economical burning of the MA. Besides the reduction of the HLW burden, the MYRRHA project will serve the purpose of developing the lead alloys technology as a reactor coolant that can be used in one of the Generation IV reactor concepts namely the Lead Fast Reactor (LFR). Although carrying out the MYRRHA project will lead to the demonstration of the efficient and safe transmutation of MA in ADS systems as the ultimate goal the

  13. Coexistence of uniquely ergodic subsystems of interval mapping

    International Nuclear Information System (INIS)

    Ye Xiangdong.

    1991-10-01

    The purpose of this paper is to show that uniquely ergodic subsystems of interval mapping also coexist in the same way as minimal sets do. To do this we give some notations in section 2. In section 3 we define D-function of a uniquely ergodic system and show its basic properties. We prove the coexistence of uniquely ergodic subsystems of interval mapping in section 4. Lastly we give the examples of uniquely ergodic systems with given D-functions in section 5. 27 refs

  14. Affective and cognitive meta-bases of attitudes: Unique effects on information interest and persuasion.

    Science.gov (United States)

    See, Ya Hui Michelle; Petty, Richard E; Fabrigar, Leandre R

    2008-06-01

    The authors investigated the predictive utility of people's subjective assessments of whether their evaluations are affect- or cognition driven (i.e., meta-cognitive bases) as separate from whether people's attitudes are actually affect- or cognition based (i.e., structural bases). Study 1 demonstrated that meta-bases uniquely predict interest in affective versus cognitive information above and beyond structural bases and other related variables (i.e., need for cognition and need for affect). In Study 2, meta-bases were shown to account for unique variance in attitude change as a function of appeal type. Finally, Study 3 showed that as people became more deliberative in their judgments, meta-bases increased in predictive utility, and structural bases decreased in predictive utility. These findings support the existence of meta-bases of attitudes and demonstrate that meta-bases are distinguishable from structural bases in their predictive utility. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

  15. On the accuracy, uniqueness and implication of dimensionless accidental relations between fundamental constants

    International Nuclear Information System (INIS)

    Bahran, M.; Univ. of Oklahoma, Norman-OK,

    2002-01-01

    Ibrahim et al(1) found an accidental formula relating the gravitational coupling constant, the electromagnetic fine structure constant and the proton to electron mass ratio. This work comments on such relation, in particular it studies the accuracy, uniqueness and unification implication of such accidental relation.(author)

  16. Unique functional properties of somatostatin-expressing GABAergic neurons in mouse barrel cortex.

    NARCIS (Netherlands)

    Gentet, L.J.; Kremer, Y.; Taniguchi, H.; Huang, Z.J.; Staiger, J.F.; Petersen, C.C.H.

    2012-01-01

    Neocortical GABAergic neurons have diverse molecular, structural and electrophysiological features, but the functional correlates of this diversity are largely unknown. We found unique membrane potential dynamics of somatostatin-expressing (SOM) neurons in layer 2/3 of the primary somatosensory

  17. On the Existence and Uniqueness of JML Estimates for the Partial Credit Model

    Science.gov (United States)

    Bertoli-Barsotti, Lucio

    2005-01-01

    A necessary and sufficient condition is given in this paper for the existence and uniqueness of the maximum likelihood (the so-called joint maximum likelihood) estimate of the parameters of the Partial Credit Model. This condition is stated in terms of a structural property of the pattern of the data matrix that can be easily verified on the basis…

  18. Frames of References – Art Museums as Unique Visual Media

    Directory of Open Access Journals (Sweden)

    Aneta Hristova

    2015-10-01

    Full Text Available The age old activity of collecting arts is not intrinsically dependent on the art museum as separate architectural type. How was the art museum as an independent structure conceptualized and why? What was the idea behind that concept? Was it created as a medium consciously and what kind of messages was it supposed to deliver? What kind of unique “textual” overlaps the various disciplines of archaeology, art history, politics, literature, science and architecture created in order to produce what we today recognize as art museum space? This study focuses on the crucial historical moments of the late 17th century when such questions were posed for the first time within the classical discourse of the French architectural theory which followed the consolidation of French absolutism and the foundation of the Royal academies of arts and sciences, until the mid 19th century when the answers to those questions were finally exemplified in built architecture. The study gives a comprehensive overview of the cultural context art museums as public institutions emerged from and became new spatial models for collective cultivation.

  19. The unique cysteine knot regulates the pleotropic hormone leptin.

    Directory of Open Access Journals (Sweden)

    Ellinor Haglund

    Full Text Available Leptin plays a key role in regulating energy intake/expenditure, metabolism and hypertension. It folds into a four-helix bundle that binds to the extracellular receptor to initiate signaling. Our work on leptin revealed a hidden complexity in the formation of a previously un-described, cysteine-knotted topology in leptin. We hypothesized that this unique topology could offer new mechanisms in regulating the protein activity. A combination of in silico simulation and in vitro experiments was used to probe the role of the knotted topology introduced by the disulphide-bridge on leptin folding and function. Our results surprisingly show that the free energy landscape is conserved between knotted and unknotted protein, however the additional complexity added by the knot formation is structurally important. Native state analyses led to the discovery that the disulphide-bond plays an important role in receptor binding and thus mediate biological activity by local motions on distal receptor-binding sites, far removed from the disulphide-bridge. Thus, the disulphide-bridge appears to function as a point of tension that allows dissipation of stress at a distance in leptin.

  20. The companion dog as a unique translational model for aging.

    Science.gov (United States)

    Mazzatenta, Andrea; Carluccio, Augusto; Robbe, Domenico; Giulio, Camillo Di; Cellerino, Alessandro

    2017-10-01

    The dog is a unique species due to its wide variation among breeds in terms of size, morphology, behaviour and lifespan, coupled with a genetic structure that facilitates the dissection of the genetic architecture that controls these traits. Dogs and humans co-evolved and share recent evolutionary selection processes, such as adaptation to digest starch-rich diets. Many diseases of the dog have a human counterpart, and notably Alzheimer's disease, which is otherwise difficult to model in other organisms. Unlike laboratory animals, companion dogs share the human environment and lifestyle, are exposed to the same pollutants, and are faced with pathogens and infections. Dogs represented a very useful model to understand the relationship between size, insulin-like growth factor-1 genetic variation and lifespan, and have been used to test the effects of dietary restriction and immunotherapy for Alzheimer's disease. Very recently, rapamycin was tested in companion dogs outside the laboratory, and this approach where citizens are involved in research aimed at the benefit of dog welfare might become a game changer in geroscience. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Unique physiology of host-parasite interactions in microsporidia infections.

    Science.gov (United States)

    Williams, Bryony A P

    2009-11-01

    Microsporidia are intracellular parasites of all major animal lineages and have a described diversity of over 1200 species and an actual diversity that is estimated to be much higher. They are important pathogens of mammals, and are now one of the most common infections among immunocompromised humans. Although related to fungi, microsporidia are atypical in genomic biology, cell structure and infection mechanism. Host cell infection involves the rapid expulsion of a polar tube from a dormant spore to pierce the host cell membrane and allow the direct transfer of the spore contents into the host cell cytoplasm. This intimate relationship between parasite and host is unique. It allows the microsporidia to be highly exploitative of the host cell environment and cause such diverse effects as the induction of hypertrophied cells to harbour prolific spore development, host sex ratio distortion and host cell organelle and microtubule reorganization. Genome sequencing has revealed that microsporidia have achieved this high level of parasite sophistication with radically reduced proteomes and with many typical eukaryotic pathways pared-down to what appear to be minimal functional units. These traits make microsporidia intriguing model systems for understanding the extremes of reductive parasite evolution and host cell manipulation.

  2. Origin of the unique ventilatory apparatus of turtles.

    Science.gov (United States)

    Lyson, Tyler R; Schachner, Emma R; Botha-Brink, Jennifer; Scheyer, Torsten M; Lambertz, Markus; Bever, G S; Rubidge, Bruce S; de Queiroz, Kevin

    2014-11-07

    The turtle body plan differs markedly from that of other vertebrates and serves as a model system for studying structural and developmental evolution. Incorporation of the ribs into the turtle shell negates the costal movements that effect lung ventilation in other air-breathing amniotes. Instead, turtles have a unique abdominal-muscle-based ventilatory apparatus whose evolutionary origins have remained mysterious. Here we show through broadly comparative anatomical and histological analyses that an early member of the turtle stem lineage has several turtle-specific ventilation characters: rigid ribcage, inferred loss of intercostal muscles and osteological correlates of the primary expiratory muscle. Our results suggest that the ventilation mechanism of turtles evolved through a division of labour between the ribs and muscles of the trunk in which the abdominal muscles took on the primary ventilatory function, whereas the broadened ribs became the primary means of stabilizing the trunk. These changes occurred approximately 50 million years before the evolution of the fully ossified shell.

  3. CERN openlab and its partners - a unique collaboration

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    Collaborating with industry is a long-standing tradition at CERN. CERN openlab is a unique example of a structure for CERN and industry to jointly carry out large-scale research and development in the field of information technologies. An initiative perceived by some as rather new, as already old by others,  the openlab this year celebrates its 10th anniversary.   CERN openlab 10th birthday celebration on 3 May 2011, on the occasion of its annual Board of Sponsors meeting, in the presence of the CERN Director-General, the partners, as well as past and present team members. © Fons Rademakers (CERN Photo Club). The idea of openlab started with Manuel Delfino, who was the head of the IT Department at the start of the millennium. “Links with industry were already in place in the computing field but lacked a general framework” explains François Fluckiger, the manager of openlab since its inception. For example, benchmarking of cutting-edge IT products ...

  4. Application of combinatorial biocatalysis for a unique ring expansion of dihydroxymethylzearalenone.

    Science.gov (United States)

    Rich, Joseph O; Budde, Cheryl L; McConeghey, Luke D; Cotterill, Ian C; Mozhaev, Vadim V; Singh, Sheo B; Goetz, Michael A; Zhao, Annie; Michels, Peter C; Khmelnitsky, Yuri L

    2009-06-01

    Combinatorial biocatalysis was applied to generate a diverse set of dihydroxymethylzearalenone analogs with modified ring structure. In one representative chemoenzymatic reaction sequence, dihydroxymethylzearalenone was first subjected to a unique enzyme-catalyzed oxidative ring opening reaction that creates two new carboxylic groups on the molecule. These groups served as reaction sites for further derivatization involving biocatalytic ring closure reactions with structurally diverse bifunctional reagents, including different diols and diamines. As a result, a library of cyclic bislactones and bislactams was created, with modified ring structures covering chemical space and structure activity relationships unattainable by conventional synthetic means.

  5. Unique strategies for technical information management at Johnson Space Center

    Science.gov (United States)

    Krishen, Vijay

    1994-01-01

    In addition to the current NASA manned programs, the maturation of Space Station and the introduction of the Space Exploration programs are anticipated to add substantially to the number and variety of data and documentation at NASA Johnson Space Center (JSC). This growth in the next decade has been estimated at five to ten fold compared to the current numbers. There will be an increased requirement for the tracking and currency of space program data and documents with National pressures to realize economic benefits from the research and technological developments of space programs. From a global perspective the demand for NASA's technical data and documentation is anticipated to increase at local, national, and international levels. The primary users will be government, industry, and academia. In our present national strategy, NASA's research and technology will assume a great role in the revitalization of the economy and gaining international competitiveness. Thus, greater demand will be placed on NASA's data and documentation resources. In this paper the strategies and procedures developed by DDMS, Inc., to accommodate the present and future information utilization needs are presented. The DDMS, Inc., strategies and procedures rely on understanding user requirements, library management issues, and technological applications for acquiring, searching, storing, and retrieving specific information accurately and quickly. The proposed approach responds to changing customer requirements and product deliveries. The unique features of the proposed strategy include: (1) To establish customer driven data and documentation management through an innovative and unique methods to identify needs and requirements. (2) To implement a structured process which responds to user needs, aimed at minimizing costs and maximizing services, resulting in increased productivity. (3) To provide a process of standardization of services and procedures. This standardization is the central

  6. Customization: Ideal Varieties, Product Uniqueness and Price Competition

    OpenAIRE

    Oksana Loginova; X. Henry Wang

    2009-01-01

    We study customization in the Hotelling model with two firms. In addition to providing ideal varieties, the perceived uniqueness of a customized product contributes independently to consumer utility. We show that only when consumer preferences for uniqueness are high customization occurs in equilibrium.

  7. Unique Protein Signature of Circulating Microparticles in Systemic Lupus Erythematosus

    DEFF Research Database (Denmark)

    Østergaard, Ole; Nielsen, Christoffer; Iversen, Line V

    2013-01-01

    To characterize the unique qualities of proteins associated with circulating subcellular material in systemic lupus erythematosus (SLE) patients compared with healthy controls and patients with other chronic autoimmune diseases.......To characterize the unique qualities of proteins associated with circulating subcellular material in systemic lupus erythematosus (SLE) patients compared with healthy controls and patients with other chronic autoimmune diseases....

  8. Can facial uniqueness be inferred from impostor scores?

    NARCIS (Netherlands)

    Dutta, A.; Veldhuis, Raymond N.J.; Spreeuwers, Lieuwe Jan

    2013-01-01

    In Biometrics, facial uniqueness is commonly inferred from impostor similarity scores. In this paper, we show that such uniqueness measures are highly unstable in the presence of image quality variations like pose, noise and blur. We also experimentally demonstrate the instability of a recently

  9. What is IgG4? A review of the biology of a unique immunoglobulin subtype.

    Science.gov (United States)

    Nirula, Ajay; Glaser, Scott M; Kalled, Susan L; Taylor, Frederick R; Taylora, Frederick R

    2011-01-01

    Recent descriptions of the group of clinical disorders collectively defined as IgG4-related systemic disease (IgG4-RSD) have prompted this review of the unique biology of the IgG4 antibody. This article will discuss IgG4 structure and function, the unique phenomenon of half-antibody exchange, and the implications of IgG4 biology for its proposed role in immunologic diseases. IgG4 antibodies have unique structural and functional properties and undergo 'half-antibody exchange' in vivo, resulting in recombined antibodies composed of two different binding specificities. The production of IgG4 antibodies appears to be driven in part by T helper 2 (Th2) cytokines that mediate allergic responses and IgE production. Although serum IgG4 levels in healthy individuals vary significantly, data from multiple sclerosis (MS) patients suggest tight regulation of individual IgG4 levels over time. IgG4-RSD represents a diverse group of clinical disorders unified by elevated IgG4 levels and specific histopathologic findings. A key unanswered question is whether IgG4, a relatively weak activator of effector cells, is pathogenic in these disorders. IgG4 is a unique antibody biologically and structurally. Increased understanding of its precise role in the clinical syndromes that comprise IgG4-RSD may ultimately elucidate the underlying pathogenesis.

  10. The Congenital Heart Surgeons Society Datacenter: unique attributes as a research organization.

    Science.gov (United States)

    Caldarone, Christopher A; Williams, William G

    2010-01-01

    Over the last 25 years, the Congenital Heart Surgeons Society (CHSS) has evolved from an informal club to a mature organization. A central feature of the CHSS has been dedication to evaluating outcomes of congenital heart surgery across a wide array of clinical diagnoses. These research activities have been orchestrated through the CHSS Datacenter, which has developed a unique organizational structure that has strengths and weaknesses in comparison to other research organizational structures (e.g., prospective randomized trials, registries, etc). This review will highlight the unique attributes of the CHSS Datacenter with emphasis on the Datacenter's strengths and weaknesses in comparison to other organizational structures. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  11. Changes in unique hues induced by chromatic surrounds.

    Science.gov (United States)

    Klauke, Susanne; Wachtler, Thomas

    2016-03-01

    A chromatic surround can have a strong influence on the perceived hue of a stimulus. We investigated whether chromatic induction has similar effects on the perception of colors that appear pure and unmixed (unique red, green, blue, and yellow) as on other colors. Subjects performed unique hue settings of stimuli in isoluminant surrounds of different chromaticities. Compared with the settings in a neutral gray surround, unique hue settings altered systematically with chromatic surrounds. The amount of induced hue shift depended on the difference between stimulus and surround hues, and was similar for unique hue settings as for settings of nonunique hues. Intraindividual variability in unique hue settings was roughly twice as high as for settings obtained in asymmetric matching experiments, which may reflect the presence of a reference stimulus in the matching task. Variabilities were also larger with chromatic surrounds than with neutral gray surrounds, for both unique hue settings and matching of nonunique hues. The results suggest that the neural representations underlying unique hue percepts are influenced by the same neural processing mechanisms as the percepts of other colors.

  12. Unique relations among anxiety sensitivity factors and anxiety, depression, and suicidal ideation.

    Science.gov (United States)

    Allan, Nicholas P; Capron, Daniel W; Raines, Amanda M; Schmidt, Norman B

    2014-03-01

    Anxiety sensitivity (AS) is composed of three lower-order dimensions, cognitive concerns, physical concerns, and social concerns. We examined the relations between AS dimensions using a more adequate assessment of subscales (ASI-3) than has previously been used, and measures of anxiety and mood disorders as well as suicidal ideation in a sample of 256 (M age = 37.10 years, SD = 16.40) treatment-seeking individuals using structural equation modeling. AS cognitive concerns was uniquely associated with generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), major depressive disorder (MDD), post-traumatic stress disorder (PTSD), and suicidal ideation. AS physical concerns was uniquely associated with OCD, social anxiety disorder (SAD), panic disorder (PD), and specific phobia. AS social concerns was uniquely associated with SAD, GAD, OCD, and MDD. These results highlight the importance of considering the lower-order AS dimensions when examining the relations between AS and psychopathology. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Non-unique Product Groups on Two Generators

    OpenAIRE

    Carter, William Paul

    2007-01-01

    The main purpose of this paper is to better understand groups that do not have the unique product property. In particular, the goal is to better understand Promislow's example, G, of such a group. In doing so, we will develop methods for generating examples of other sets that do not have the unique product property. With these methods we can show that there exists other distinct 14 element, square, non-unique product sets in G that are not inversions or translations. Also, this paper answers ...

  14. Guide to good practices for operations aspects of unique processes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This Guide to Good Practices is written to enhance understanding of, and provide direction for, Operations Aspects of Facility Chemistry and Unique Processes, Chapter XIII of Department of Energy (DOE) Order 5480.19, Conduct of Operations Requirements for DOE Facilities. The practices in this guide should be considered when planning or reviewing employee training and facility management programs. Contractors are advised to adopt procedures that meet the intent of DOE Order 5480.19. Operations Aspects of Unique Processes is an element of an effective Conduct of Operations program. The complexity and array of activities performed in DOE facilities dictate the necessity for all personnel to coordinate interrelated activities affecting unique processes.

  15. PET-CT in the typification of unique pulmonary injuries

    International Nuclear Information System (INIS)

    Cobos, P.; San Roman, Jose L.; Dalurzo, L.

    2007-01-01

    The objective of this document is to evaluate the usefulness of the PET-CT for the characterization of the unique pulmonary injuries. Retrospective analysis was made to patients with unique pulmonary injuries who carried out a PET-CT in the Italian Hospital between May of 2003 - March of 2005. Those patients with pulmonary outlying nodule, or unique pulmonary mass that had pathological anatomy of injury or follow-up through a computed tomography of thorax made with an interval of time not minor at 2 years of the PET-CT were included [es

  16. Programmable self-assembly of three-dimensional nanostructures from 10,000 unique components

    Science.gov (United States)

    Ong, Luvena L.; Hanikel, Nikita; Yaghi, Omar K.; Grun, Casey; Strauss, Maximilian T.; Bron, Patrick; Lai-Kee-Him, Josephine; Schueder, Florian; Wang, Bei; Wang, Pengfei; Kishi, Jocelyn Y.; Myhrvold, Cameron; Zhu, Allen; Jungmann, Ralf; Bellot, Gaetan; Ke, Yonggang; Yin, Peng

    2017-12-01

    Nucleic acids (DNA and RNA) are widely used to construct nanometre-scale structures with ever increasing complexity, with possible application in fields such as structural biology, biophysics, synthetic biology and photonics. The nanostructures are formed through one-pot self-assembly, with early kilodalton-scale examples containing typically tens of unique DNA strands. The introduction of DNA origami, which uses many staple strands to fold one long scaffold strand into a desired structure, has provided access to megadalton-scale nanostructures that contain hundreds of unique DNA strands. Even larger DNA origami structures are possible, but manufacturing and manipulating an increasingly long scaffold strand remains a challenge. An alternative and more readily scalable approach involves the assembly of DNA bricks, which each consist of four short binding domains arranged so that the bricks can interlock. This approach does not require a scaffold; instead, the short DNA brick strands self-assemble according to specific inter-brick interactions. First-generation bricks used to create three-dimensional structures are 32 nucleotides long, consisting of four eight-nucleotide binding domains. Protocols have been designed to direct the assembly of hundreds of distinct bricks into well formed structures, but attempts to create larger structures have encountered practical challenges and had limited success. Here we show that DNA bricks with longer, 13-nucleotide binding domains make it possible to self-assemble 0.1-1-gigadalton, three-dimensional nanostructures from tens of thousands of unique components, including a 0.5-gigadalton cuboid containing about 30,000 unique bricks and a 1-gigadalton rotationally symmetric tetramer. We also assembled a cuboid that contains around 10,000 bricks and about 20,000 uniquely addressable, 13-base-pair ‘voxels’ that serves as a molecular canvas for three-dimensional sculpting. Complex, user-prescribed, three-dimensional cavities can

  17. Phase field theory of proper displacive phase transformations: Structural anisotropy and directional flexibility, a vector model, and the transformation kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Rao Weifeng [Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ 08854 (United States); Khachaturyan, Armen G., E-mail: khach@jove.rutgers.edu [Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ 08854 (United States)

    2011-06-15

    A phase field theory of proper displacive transformations is developed to address the microstructure evolution and its response to applied fields in decomposing and martensitic systems. The theory is based on the explicit equation for the non-equilibrium free energy function of the transformation strain obtained by a consistent separation of the total strain into transformation and elastic strains. The transformation strain is considered to be a relaxing long-range order parameter evolving in accordance with the system energetics rather than as a fixed material constant used in the conventional Eshelby theory of coherent inclusions. The elastic strain is defined as a coherency strain recovering the crystal lattice compatibility. The obtained free energy function of the transformation strain leads to the concepts of structural anisotropy and directional flexibility of low symmetry phases. The formulated vector model of displacive transformation makes apparent a similarity between proper displacive transformation and ferromagnetic/ferroelectric transformation and, in particular, a similarity between the structural anisotropy and magnetic/polar anisotropy of ferromagnetic/ferroelectric materials. It even predicts the feasibility of a glass-like structural state with unlimited directional flexibility of the transformation strain that is conceptually similar to a ferromagnetic glass. The thermodynamics of the equilibrium between low symmetry phases and the thermodynamic conditions leading to the formation of adaptive states are formulated.

  18. Holistic Leadership-Nursing's Unique Contribution to Healthcare.

    Science.gov (United States)

    Clarke, Pamela N; Bleich, Michael R

    2018-04-01

    This dialogue is focused on holistic leadership from the perspective of a well-known leader in nursing. He frames the changing healthcare environment and nursing's unique contribution on the interprofessional team.

  19. The Tankwa Karoo National Park feral goat population: A unique ...

    African Journals Online (AJOL)

    The Tankwa Karoo National Park feral goat population: A unique genetic ... The feral goats from Tankwa Karoo National Park in the Northern Cape, South Africa, ... Park and former Tankwa goats, now kept on a private farm were genotyped, ...

  20. Protein nanoparticle: A unique system as drug delivery vehicles

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... Nanobiotechnology Research Center, Faculty of Chemical Engineering, Babol University of Technology, Iran. ... as potential carriers with unique advantages including ..... for intracellular uptake in BT/20 human breast cancer.

  1. Unique morphology of dispersed clay particles in a polymer nanocomposite

    CSIR Research Space (South Africa)

    Malwela, T

    2011-02-01

    Full Text Available This communication reports a unique morphology of dispersed clay particles in a polymer nanocomposite. A nanocomposite of poly[butylene succinate)-co-adipate] (PBSA) with 3 wt% of organically modified montmorillonite was prepared by melt...

  2. Determining hydraulic parameters of a karst aquifer using unique ...

    African Journals Online (AJOL)

    2014-07-15

    Jul 15, 2014 ... 1 Faculty of Natural Sciences, Potchefstroom Campus, North-West University, ... a first-ever attempt to utilise various sets of unique historical data ..... Even though the aquifer shows characteristics of all major ...... Earth Sci.

  3. Uniqueness of the electrostatic solution in Schwarzschild space

    International Nuclear Information System (INIS)

    Molnar, Pal G.; Elsaesser, Klaus

    2003-01-01

    In this Brief Report we give the proof that the solution of any static test charge distribution in Schwarzschild space is unique. In order to give the proof we derive the first Green's identity written with p-forms on (pseudo) Riemannian manifolds. Moreover, the proof of uniqueness can be shown for either any purely electric or purely magnetic field configuration. The spacetime geometry is not crucial for the proof

  4. Practical relevance of pattern uniqueness in forensic science.

    Science.gov (United States)

    Jayaprakash, Paul T

    2013-09-10

    Uniqueness being unprovable, it has recently been argued that individualization in forensic science is irrelevant and, probability, as applied for DNA profiles, should be applied for all identifications. Critiques against uniqueness have omitted physical matching, a realistic and tangible individualization that supports uniqueness. Describing case examples illustrating pattern matches including physical matching, it is indicated that individualizations are practically relevant for forensic science as they establish facts on a definitive basis providing firm leads benefitting criminal investigation. As a tenet of forensic identification, uniqueness forms a fundamental paradigm relevant for individualization. Evidence on the indeterministic and stochastic causal pathways of characteristics in patterns available in the related fields of science sufficiently supports the proposition of uniqueness. Characteristics involved in physical matching and matching achieved in patterned evidence existing in the state of nature are not events amenable for counting; instead these are ensemble of visible units occupying the entire pattern area stretching the probability of re-occurrence of a verisimilitude pattern into infinity offering epistemic support to uniqueness. Observational methods are as respectable as instrumental or statistical methods since they are capable of generating results that are tangible and obviously valid as in physical matching. Applying the probabilistic interpretation used for DNA profiles to the other patterns would be unbefitting since these two are disparate, the causal pathways of the events, the loci, in the manipulated DNA profiles being determinable. While uniqueness enables individualizations, it does not vouch for eliminating errors. Instead of dismissing uniqueness and individualization, accepting errors as human or system failures and seeking remedial measures would benefit forensic science practice and criminal investigation. Copyright © 2013

  5. Investigation of unique hue setting changes with ageing

    Institute of Scientific and Technical Information of China (English)

    Chenyang Fu; Kaida Xiao; Dimosthenis Karatzas; Sophie Wuerger

    2011-01-01

    Clromatic sensitivity along the protan, deutan, and tritan lines and the loci of the unique hues (red, green,yellow, blue) for a very large sample (n = 185) of colour-normal observers ranging from 18 to 75 years of age are assessed. Visual judgments are obtained under normal viewing conditions using colour patches on self-luminous display under controlled adaptation conditions. Trivector discrimination thresholds show an increase as a function of age along the protan, deutan, and tritan axes, with the largest increase present along the tritan line, less pronounced shifts in unique hue settings are also observed. Based on the chromatic (protan, deutan, tritan) thresholds and using scaled cone signals, we predict the unique hue changes with ageing. A dependency on age for unique red and unique yellow for predicted hue angle is found. We conclude that the chromatic sensitivity deteriorates significantly with age, whereas the appearance of unique hues is much less affected, remaining almost constant despite the known changes in the ocular media.%@@ Clromatic sensitivity along the protan, deutan, and tritan lines and the loci of the unique hues (red, green,yellow, blue) for a very large sample (n = 185) of colour-normal observers ranging from 18 to 75 years of age are assessed.Visual judgments are obtained under normal viewing conditions using colour patches on self-luminous display under controlled adaptation conditions.Trivector discrimination thresholds show an increase as a function of age along the protan, deutan, and tritan axes, with the largest increase present along the tritan line, less pronounced shifts in unique hue settings are also observed.

  6. Denture identification using unique identification authority of India barcode

    OpenAIRE

    Sudhindra Mahoorkar; Anoop Jain

    2013-01-01

    Over the years, various denture marking systems have been reported in the literature for personal identification. They have been broadly divided into surface marking and inclusion methods. In this technique, patient's unique identification number and barcode printed in the patient's Aadhaar card issued by Unique Identification Authority of India (UIDAI) are used as denture markers. This article describes a simple, quick, and economical method for identification of individual.

  7. Denture identification using unique identification authority of India barcode.

    Science.gov (United States)

    Mahoorkar, Sudhindra; Jain, Anoop

    2013-01-01

    Over the years, various denture marking systems have been reported in the literature for personal identification. They have been broadly divided into surface marking and inclusion methods. In this technique, patient's unique identification number and barcode printed in the patient's Aadhaar card issued by Unique Identification Authority of India (UIDAI) are used as denture markers. This article describes a simple, quick, and economical method for identification of individual.

  8. Unique interconnected graphene/SnO2 nanoparticle spherical multilayers for lithium-ion battery applications.

    Science.gov (United States)

    Shao, Qingguo; Tang, Jie; Sun, Yige; Li, Jing; Zhang, Kun; Yuan, Jinshi; Zhu, Da-Ming; Qin, Lu-Chang

    2017-03-30

    We have designed and synthesized a unique structured graphene/SnO 2 composite, where SnO 2 nanoparticles are inserted in between interconnected graphene sheets which form hollow spherical multilayers. The hollow spherical multilayered structure provides much flexibility to accommodate the configuration and volume changes of SnO 2 in the material. When it is used as an anode material for lithium-ion batteries, such a novel nanostructure can not only provide a stable conductive matrix and suppress the mechanical stress, but also eliminate the need of any binders for constructing electrodes. Electrochemical tests show that the unique graphene/SnO 2 composite electrode as designed could exhibit a large reversible capacity over 1000 mA h g -1 and long cycling life with 88% retention after 100 cycles. These results indicate the great potential of the composite for being used as a high performance anode material for lithium-ion batteries.

  9. Carotamine, a Unique Aromatic Amide from Daucus Carota L. Var Biossieri (Apiaceae

    Directory of Open Access Journals (Sweden)

    Mohamed M. El-Azizi

    2002-06-01

    Full Text Available The unique aromatic peptide 4-(p-aminobenzoylamino-2-aminobenzoic acid, carotamine, together with 2,4-diaminobenzoic acid, isolated for the first time from a plant source, were identified from the aqueous alcoholic extract of the aerial parts of Daucus carota L. var. boissieri (Apiaceae. The structures were determined through conventional methods of analysis and confirmed by LC-ESI/MS and NMR spectral analysis.

  10. Executive Functions Contribute Uniquely to Reading Competence in Minority Youth

    Science.gov (United States)

    Jacobson, Lisa A.; Koriakin, Taylor; Lipkin, Paul; Boada, Richard; Frijters, Jan; Lovett, Maureen; Hill, Dina; Willcutt, Erik; Gottwald, Stephanie; Wolf, Maryanne; Bosson-Heenan, Joan; Gruen, Jeffrey R.; Mahone, E. Mark

    2018-01-01

    Competent reading requires various skills beyond those for basic word reading (i.e., core language skills, rapid naming, phonological processing). Contributing “higher-level” or domain-general processes include information processing speed and executive functions (working memory, strategic problem solving, attentional switching). Research in this area has relied on largely Caucasian samples, with limited representation of children from racial or ethnic minority groups. This study examined contributions of executive skills to reading competence in 761 children of minority backgrounds. Hierarchical linear regressions examined unique contributions of executive functions (EF) to word reading, fluency, and comprehension. EF contributed uniquely to reading performance, over and above reading-related language skills; working memory contributed uniquely to all components of reading; while attentional switching, but not problem solving, contributed to isolated and contextual word reading and reading fluency. Problem solving uniquely predicted comprehension, suggesting that this skill may be especially important for reading comprehension in minority youth. Attentional switching may play a unique role in development of reading fluency in minority youth, perhaps as a result of the increased demand for switching between spoken versus written dialects. Findings have implications for educational and clinical practice with regard to reading instruction, remedial reading intervention, and assessment of individuals with reading difficulty. PMID:26755569

  11. Structural region

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Structural region. The two groups had 4 substitutions similar to Yawat strain. The Yawat strain had 5 unique mutations. 3 in the E2 region and 2 in the E1 region. The mutation, I702V (E2), though different from all the recent Indian and Reunion sequences was similar ...

  12. Uniqueness: skews bit occurrence frequencies in randomly generated fingerprint libraries.

    Science.gov (United States)

    Chen, Nelson G

    2016-08-01

    Requiring that randomly generated chemical fingerprint libraries have unique fingerprints such that no two fingerprints are identical causes a systematic skew in bit occurrence frequencies, the proportion at which specified bits are set. Observed frequencies (O) at which each bit is set within the resulting libraries systematically differ from frequencies at which bits are set at fingerprint generation (E). Observed frequencies systematically skew toward 0.5, with the effect being more pronounced as library size approaches the compound space, which is the total number of unique possible fingerprints given the number of bit positions each fingerprint contains. The effect is quantified for varying library sizes as a fraction of the overall compound space, and for changes in the specified frequency E. The cause and implications for this systematic skew are subsequently discussed. When generating random libraries of chemical fingerprints, the imposition of a uniqueness requirement should either be avoided or taken into account.

  13. Word from the CSO - CERN’s unique scientific breadth

    CERN Multimedia

    2008-01-01

    Whilst we are all clearly focused on completion of the LHC and the detectors around it and look forward to a successful start of operations later this year, we should not forget that CERN has yet more to offer in addition to this highest priority programme ‘at the energy frontier’. Indeed, CERN also attracts a large scientific community seizing the opportunities offered by its other facilities. Sometimes I wonder whether we are not too modest and should not emphasize more CERN’s unique scientific breadth. ISOLDE, at the PS Booster, relies on innovative techniques to produce results at the forefront of nuclear physics very cost-effectively. nTOF has provided unique measurements of interest to nuclear technology, nuclear astrophysics and basic nuclear physics, and still has an ambitious programme ahead of it after refurbishment of the target. Another unique facility is the Antiproton Decelerator, at which the study of antimatter is being pursued with ingenious experiment...

  14. RUCS: Rapid identification of PCR primers for unique core sequences

    DEFF Research Database (Denmark)

    Thomsen, Martin Christen Frølund; Hasman, Henrik; Westh, Henrik

    2017-01-01

    Designing PCR primers to target a specific selection of whole genome sequenced strains can be a long, arduous, and sometimes impractical task. Such tasks would benefit greatly from an automated tool to both identify unique targets, and to validate the vast number of potential primer pairs...... for the targets in silico . Here we present RUCS, a program that will find PCR primer pairs and probes for the unique core sequences of a positive genome dataset complement to a negative genome dataset. The resulting primer pairs and probes are in addition to simple selection also validated through a complex...... in silico PCR simulation. We compared our method, which identifies the unique core sequences, against an existing tool called ssGeneFinder, and found that our method was 6.5-20 times more sensitive. We used RUCS to design primer pairs that would target a set of genomes known to contain the mcr-1 colistin...

  15. Flexible and efficient genome tiling design with penalized uniqueness score

    Directory of Open Access Journals (Sweden)

    Du Yang

    2012-12-01

    Full Text Available Abstract Background As a powerful tool in whole genome analysis, tiling array has been widely used in the answering of many genomic questions. Now it could also serve as a capture device for the library preparation in the popular high throughput sequencing experiments. Thus, a flexible and efficient tiling array design approach is still needed and could assist in various types and scales of transcriptomic experiment. Results In this paper, we address issues and challenges in designing probes suitable for tiling array applications and targeted sequencing. In particular, we define the penalized uniqueness score, which serves as a controlling criterion to eliminate potential cross-hybridization, and a flexible tiling array design pipeline. Unlike BLAST or simple suffix array based methods, computing and using our uniqueness measurement can be more efficient for large scale design and require less memory. The parameters provided could assist in various types of genomic tiling task. In addition, using both commercial array data and experiment data we show, unlike previously claimed, that palindromic sequence exhibiting relatively lower uniqueness. Conclusions Our proposed penalized uniqueness score could serve as a better indicator for cross hybridization with higher sensitivity and specificity, giving more control of expected array quality. The flexible tiling design algorithm incorporating the penalized uniqueness score was shown to give higher coverage and resolution. The package to calculate the penalized uniqueness score and the described probe selection algorithm are implemented as a Perl program, which is freely available at http://www1.fbn-dummerstorf.de/en/forschung/fbs/fb3/paper/2012-yang-1/OTAD.v1.1.tar.gz.

  16. Human uniqueness-self-interest and social cooperation.

    Science.gov (United States)

    Okada, Daijiro; Bingham, Paul M

    2008-07-21

    Humans are unique among all species of terrestrial history in both ecological dominance and individual properties. Many, or perhaps all, of the unique elements of this nonpareil status can be plausibly interpreted as evolutionary and strategic elements and consequences of the unprecedented intensity and scale of our social cooperation. Convincing explanation of this unique human social adaptation remains a central, unmet challenge to the scientific enterprise. We develop a hypothesis for the ancestral origin of expanded cooperative social behavior. Specifically, we present a game theoretic analysis demonstrating that a specific pattern of expanded social cooperation between conspecific individuals with conflicts of interest (including non-kin) can be strategically viable, but only in animals that possess a highly unusual capacity for conspecific violence (credible threat) having very specific properties that dramatically reduce the costs of coercive violence. The resulting reduced costs allow preemptive or compensated coercion to be an instantaneously self-interested behavior under diverse circumstances rather than in rare, idiosyncratic circumstances as in actors (animals) who do not have access to inexpensive coercive threat. Humans are apparently unique among terrestrial organisms in having evolved conspecific coercive capabilities that fulfill these stringent requirements. Thus, our results support the proposal that access to a novel capacity for projection of coercive threat might represent the essential initiating event for the evolution of a human-like pattern of social cooperation and the subsequent evolution of the diverse features of human uniqueness. Empirical evidence indicates that these constraints were, in fact, met only in our evolutionary lineage. The logic for the emergence of uniquely human cooperation suggested by our analysis apparently accounts simply for the human fossil record.

  17. Electronic and structural ground state of heavy alkali metals at high pressure

    Science.gov (United States)

    Fabbris, G.; Lim, J.; Veiga, L. S. I.; Haskel, D.; Schilling, J. S.

    2015-02-01

    Alkali metals display unexpected properties at high pressure, including emergence of low-symmetry crystal structures, which appear to occur due to enhanced electronic correlations among the otherwise nearly free conduction electrons. We investigate the high-pressure electronic and structural ground state of K, Rb, and Cs using x-ray absorption spectroscopy and x-ray diffraction measurements together with a b i n i t i o theoretical calculations. The sequence of phase transitions under pressure observed at low temperature is similar in all three heavy alkalis except for the absence of the o C 84 phase in Cs. Both the experimental and theoretical results point to pressure-enhanced localization of the valence electrons characterized by pseudogap formation near the Fermi level and strong s p d hybridization. Although the crystal structures predicted to host magnetic order in K are not observed, the localization process appears to drive these alkalis closer to a strongly correlated electron state.

  18. A note on unique solvability of the absolute value equation

    Directory of Open Access Journals (Sweden)

    Taher Lotfi

    2014-05-01

    Full Text Available It is proved that applying sufficient regularity conditions to the interval matrix $[A-|B|,A+|B|]$‎, ‎we can create a new unique solvability condition for the absolute value equation $Ax+B|x|=b$‎, ‎since regularity of interval matrices implies unique solvability of their corresponding absolute value equation‎. ‎This condition is formulated in terms of positive definiteness of a certain point matrix‎. ‎Special case $B=-I$ is verified too as an application.

  19. Increasing Need for Uniqueness in Contemporary China: Empirical Evidence

    Directory of Open Access Journals (Sweden)

    Huajian Cai

    2018-05-01

    Full Text Available Past research has documented various cultural and psychological changes in contemporary China. In two studies, we examine how Chinese people’s need for uniqueness (NFU also has changed. In Study 1, we found a significant cross-generational increase in Chinese participants’ self-reported NFU. In Study 2, we sampled the names of Chinese newborn babies over the last five decades and found that parents have been increasingly likely to use unique characters to name their children. These findings suggest that the NFU has been rising in China, a historically collectivistic-oriented society. Theoretical and practical implications of our findings were discussed.

  20. Regional cluster policy between best practices and cultural uniqueness

    NARCIS (Netherlands)

    Hospers, Gerrit J.; Beugelsdijk, S.; Boneschansker, E.; van Dijk, J.; Jansma, L.G.J.; Verhaar, K.H.A.

    2004-01-01

    This chapter deals with an intriguing paradox in current regional economic policy: whereas unique local factors are increasingly seen as the determinants of regional economic success, more and more governments simultaneously try to copy policy experiences that have proved successful in a particular

  1. Teen camp: a unique approach to recruit future nurses.

    Science.gov (United States)

    Redding, Donna A; Riech, Sandy; Prater, Marsha A

    2004-01-01

    A collaborative and unique approach to interest high school students in nursing. To inform educators and nursing departments about an innovative approach to recruit future nurses. Professional literature and authors' experience. All students related positive experiences. The initial camp evaluation produced innovative input from the students, and each camp met its goal of creating career interest in the nursing profession.

  2. Differentiating Performance Approach Goals and Their Unique Effects

    Science.gov (United States)

    Edwards, Ordene V.

    2014-01-01

    The study differentiates between two types of performance approach goals (competence demonstration performance approach goal and normative performance approach goal) by examining their unique effects on self-efficacy, interest, and fear of failure. Seventy-nine students completed questionnaires that measure performance approach goals,…

  3. Sufficient conditions for uniqueness of the weak value

    International Nuclear Information System (INIS)

    Dressel, J; Jordan, A N

    2012-01-01

    We review and clarify the sufficient conditions for uniquely defining the generalized weak value as the weak limit of a conditioned average using the contextual values formalism introduced in Dressel, Agarwal and Jordan (2010 Phys. Rev. Lett. http://dx.doi.org/10.1103/PhysRevLett.104.240401). We also respond to criticism of our work by Parrott (arXiv:1105.4188v1) concerning a proposed counter-example to the uniqueness of the definition of the generalized weak value. The counter-example does not satisfy our prescription in the case of an underspecified measurement context. We show that when the contextual values formalism is properly applied to this example, a natural interpretation of the measurement emerges and the unique definition in the weak limit holds. We also prove a theorem regarding the uniqueness of the definition under our sufficient conditions for the general case. Finally, a second proposed counter-example by Parrott (arXiv:1105.4188v6) is shown not to satisfy the sufficiency conditions for the provided theorem. (paper)

  4. On the Existence of Unique Equilibria in Location Models

    NARCIS (Netherlands)

    Webers, H.M.

    1996-01-01

    In this paper, we study a two-stage location-then-price game where consumers are distributed piecewise uniformly, each piece being referred to as an interval.Although the firms face a coordination problem, it is obvious that, for any given locations and prices, there is a unique indifferent

  5. Marketing the Uniqueness of Small Towns. Small Town Strategy.

    Science.gov (United States)

    Hogg, David H.; Dunn, Douglas

    A small town can strengthen its local economy as a result of business people and concerned citizens collectively identifying that community's uniqueness and then capitalizing on it via advertising, personal selling, sales promotion, or publicity. This publication relates the science of marketing to communities. Seven simple techniques are provided…

  6. Secondary metabolites from the unique bamboo, Melocanna baccifera.

    Science.gov (United States)

    Govindan, Balaji; Johnson, Anil John; Viswanathan, Gayathri; Ramaswamy, Venkataraman; Koshy, Konnath Chacko; Baby, Sabulal

    2018-02-15

    Phytochemistry of fruits and leaves of the unique bamboo Melocanna baccifera resulted in the isolation of 27 secondary metabolites, including 4-Oxabicyclo[3.2.2]nona-1(7),5,8-triene and Verbacine. Biological activity studies of Verbacine revealed it as an inhibitor of acetylcholinesterase and as cytotoxic against C6 cancer cells.

  7. Uniqueness in inverse elastic scattering with finitely many incident waves

    International Nuclear Information System (INIS)

    Elschner, Johannes; Yamamoto, Masahiro

    2009-01-01

    We consider the third and fourth exterior boundary value problems of linear isotropic elasticity and present uniqueness results for the corresponding inverse scattering problems with polyhedral-type obstacles and a finite number of incident plane elastic waves. Our approach is based on a reflection principle for the Navier equation. (orig.)

  8. Unique case of esophageal rupture after a fall from height

    NARCIS (Netherlands)

    van Heijl, Mark; Saltzherr, Teun P.; van Berge Henegouwen, Mark I.; Goslings, J. Carel

    2009-01-01

    ABSTRACT: BACKGROUND: Traumatic ruptures of the esophagus are relatively rare. This condition is associated with high morbidity and mortality. Most traumatic ruptures occur after motor vehicle accidents. Case Presentation: We describe a unique case of a 23 year old woman that presented at our trauma

  9. DECISIONS ET COMPETITIVITE SUR LE MARCHE UNIQUE EUROPEEN

    Directory of Open Access Journals (Sweden)

    Sirghi Nicoleta

    2008-05-01

    Full Text Available L’un des traits importants du marché unique européen, a comme source le męme énoncé du principal objectif de l’intégration européenne ainsi que: l’harmonisation des niveaux du développement des Etats Membres et l’augmentation du niveau de vie dans l’ensemble de la communauté. Pour le marché unique européen, cet aspect se traduit par une permanente et soutenue augmentation de la demande. Cet ouvrage présente au début une analyse des éléments spécifiques du marché européen. Ensuite on identifie les opportunités et les risques au niveau macroéconomique adjointes aux perspectives du marché unique européen. Comme fondement on présente des stratégies du développement réalisables au niveau microéconomique que puissent assurer l’augmentation du niveau sur la compétitivité des sociétés sur le marché unique européen.

  10. Is Self-Assessment in Religious Education Unique?

    Science.gov (United States)

    Brooks, Val; Fancourt, Nigel

    2012-01-01

    This paper addresses the question: is self-assessment in religious education unique? It first presents an overview of some challenges for assessment from subject differences, and then reviews the generic literature on self-assessment. It builds on earlier empirical research on self-assessment in religious education, carried out in an English state…

  11. Three Unique Implementations of Processes for PyCSP

    DEFF Research Database (Denmark)

    Friborg, Rune Møllegaard; Bjørndalen, John Markus; Vinter, Brian

    2009-01-01

    In this work we motivate and describe three unique implementations of processes for PyCSP: process, thread and greenlet based. The overall purpose is to demonstrate the feasibility of Communicating Sequential Processes as a framework for different application types and target platforms. The result...

  12. Zeros and uniqueness of Q-difference polynomials of meromorphic ...

    Indian Academy of Sciences (India)

    Meromorphic functions; Nevanlinna theory; logarithmic order; uniqueness problem; difference-differential polynomial. Abstract. In this paper, we investigate the value distribution of -difference polynomials of meromorphic function of finite logarithmic order, and study the zero distribution of difference-differential polynomials ...

  13. Why Is Family Firms' Internationalization Unique? : A Meta-Analysis

    NARCIS (Netherlands)

    Arregle, Jean-Luc; Duran, Patricio; Hitt, Michael A.; van Essen, M.

    Despite its importance, there is no clear understanding of the uniqueness of family firms' internationalization. This article sheds new light on this issue with a meta-analysis of 76 studies covering 41 countries. We show that the considerable study and cross-country differences in the relationship

  14. Meeting Each Student's Unique Potential: One Approach to Education.

    Science.gov (United States)

    Gauld, Joseph W.

    1996-01-01

    By championing extrinsic motivation, the achievement-reward system short-circuits individuals' innate inner power. Achievement-oriented adults rely on their knowledge, skills, and abilities, not their deeper potential. Hyde School, in Bath, Maine, solves this problem by committing the entire school community to development of unique potential via…

  15. Determining hydraulic parameters of a karst aquifer using unique ...

    African Journals Online (AJOL)

    Although karst aquifers constitute some of the most important water resources worldwide, generally accepted methods for reliably characterising their hydraulic properties are still elusive. This paper aims at contributing to the discussion by a first-ever attempt to utilise various sets of unique historical data derived from ...

  16. Uniqueness and zeros of q-shift difference polynomials

    Indian Academy of Sciences (India)

    In this paper, we consider the zero distributions of -shift difference polynomials of meromorphic functions with zero order, and obtain two theorems that extend the classical Hayman results on the zeros of differential polynomials to -shift difference polynomials. We also investigate the uniqueness problem of -shift ...

  17. Crossover Can Be Constructive When Computing Unique Input Output Sequences

    DEFF Research Database (Denmark)

    Lehre, Per Kristian; Yao, Xin

    2010-01-01

    Unique input output (UIO) sequences have important applications in conformance testing of finite state machines (FSMs). Previous experimental and theoretical research has shown that evolutionary algorithms (EAs) can compute UIOs efficiently on many FSM instance classes, but fail on others. However...

  18. review article how unique is south african military integration?

    African Journals Online (AJOL)

    Roy Licklider

    Rutgers University. The study of civil war ... South Africa has a strong case to be the poster child of military integration after civil violence.6 In a .... One aspect of the South African response to this problem was unique: a. Defence White Paper ...

  19. Uniqueness of inverse scattering problem in local quantum physics

    Energy Technology Data Exchange (ETDEWEB)

    Schroer, Bert [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mail: schroer@cbpf.br

    2001-06-01

    It is shown that the a Bisognano-Wichmann-Unruh inspired formulation of local quantum physics which starts from wedge-localized algebras, leads to a uniqueness proof for the scattering problem. The important mathematical tool is the thermal KMS aspect of localization and its strengthening by the requirement of crossing symmetry for generalized formfactors. (author)

  20. Cone photoreceptor sensitivities and unique hue chromatic responses: correlation and causation imply the physiological basis of unique hues.

    Directory of Open Access Journals (Sweden)

    Ralph W Pridmore

    Full Text Available This paper relates major functions at the start and end of the color vision process. The process starts with three cone photoreceptors transducing light into electrical responses. Cone sensitivities were once expected to be Red Green Blue color matching functions (to mix colors but microspectrometry proved otherwise: they instead peak in yellowish, greenish, and blueish hues. These physiological functions are an enigma, unmatched with any set of psychophysical (behavioral functions. The end-result of the visual process is color sensation, whose essential percepts are unique (or pure hues red, yellow, green, blue. Unique hues cannot be described by other hues, but can describe all other hues, e.g., that hue is reddish-blue. They are carried by four opponent chromatic response curves but the literature does not specify whether each curve represents a range of hues or only one hue (a unique over its wavelength range. Here the latter is demonstrated, confirming that opponent chromatic responses define, and may be termed, unique hue chromatic responses. These psychophysical functions also are an enigma, unmatched with any physiological functions or basis. Here both enigmas are solved by demonstrating the three cone sensitivity curves and the three spectral chromatic response curves are almost identical sets (Pearson correlation coefficients r from 0.95-1.0 in peak wavelengths, curve shapes, math functions, and curve crossover wavelengths, though previously unrecognized due to presentation of curves in different formats, e.g., log, linear. (Red chromatic response curve is largely nonspectral and thus derives from two cones. Close correlation combined with deterministic causation implies cones are the physiological basis of unique hues. This match of three physiological and three psychophysical functions is unique in color vision.

  1. Cone photoreceptor sensitivities and unique hue chromatic responses: correlation and causation imply the physiological basis of unique hues.

    Science.gov (United States)

    Pridmore, Ralph W

    2013-01-01

    This paper relates major functions at the start and end of the color vision process. The process starts with three cone photoreceptors transducing light into electrical responses. Cone sensitivities were once expected to be Red Green Blue color matching functions (to mix colors) but microspectrometry proved otherwise: they instead peak in yellowish, greenish, and blueish hues. These physiological functions are an enigma, unmatched with any set of psychophysical (behavioral) functions. The end-result of the visual process is color sensation, whose essential percepts are unique (or pure) hues red, yellow, green, blue. Unique hues cannot be described by other hues, but can describe all other hues, e.g., that hue is reddish-blue. They are carried by four opponent chromatic response curves but the literature does not specify whether each curve represents a range of hues or only one hue (a unique) over its wavelength range. Here the latter is demonstrated, confirming that opponent chromatic responses define, and may be termed, unique hue chromatic responses. These psychophysical functions also are an enigma, unmatched with any physiological functions or basis. Here both enigmas are solved by demonstrating the three cone sensitivity curves and the three spectral chromatic response curves are almost identical sets (Pearson correlation coefficients r from 0.95-1.0) in peak wavelengths, curve shapes, math functions, and curve crossover wavelengths, though previously unrecognized due to presentation of curves in different formats, e.g., log, linear. (Red chromatic response curve is largely nonspectral and thus derives from two cones.) Close correlation combined with deterministic causation implies cones are the physiological basis of unique hues. This match of three physiological and three psychophysical functions is unique in color vision.

  2. Unique Action of Interleukin-18 on T Cells and Other Immune Cells

    Directory of Open Access Journals (Sweden)

    Kenji Nakanishi

    2018-04-01

    Full Text Available Interleukin (IL-18 was originally discovered as a factor that enhances interferon (IFN-γ production by anti-CD3-stimulated Th1 cells, particularly in association with IL-12. IL-12 is a cytokine that induces development of Th1 cells. IL-18 cannot induce Th1 cell development, but has the capacity to activate established Th1 cells to produce IFN-γ in the presence of IL-12. Thus, IL-18 is regarded as a proinflammatory cytokine that facilitates type 1 responses. However, in the absence of IL-12 but presence of IL-2, IL-18 stimulates natural killer cells, NKT cells, and even established Th1 cells to produce IL-3, IL-9, and IL-13. Thus, IL-18 also facilitates type 2 responses. This unique function of IL-18 contributes to infection-associated allergic diseases. Together with IL-3, IL-18 stimulates mast cells and basophils to produce IL-4, IL-13, and chemical mediators such as histamine. Thus, IL-18 also induces innate-type allergic inflammation. IL-18 belongs to the IL-1 family of cytokines, which share similar molecular structures, receptors structures, and signal transduction pathways. Nevertheless, IL-18 shows a unique function by binding to a specific receptor expressed on distinct types of cells. In this review article, I will focus on the unique features of IL-18 in lymphocytes, basophils, and mast cells, particularly in comparison with IL-33.

  3. Top measurements of pulsed neutrons for texture analysis of low symmetry materials

    International Nuclear Information System (INIS)

    Larson, A.C.; Vergamini, P.J.; Wenk, H.R.

    1990-01-01

    The single crystal diffractometer at LANSCE, SCD, provides an ideal capability for the study of preferred orientation in geological samples by time-of flight (TOF) measurement of pulsed neutrons. The 2-d position sensitive neutron detector with the large wave length range allows one to measure the complete distribution of intensities for several poles very quickly. Each histogram covers about π 2 /16 radians of reciprocal space and contains information from all possible poles visible with the wave length range used, usually about 0.5 to 5.0 Angstrom. With this method complete pole figures of many lattice planes can be constructed from only 12 to 20 sample orientations as compared to over 1000 sample settings per lattice plane using conventional diffractometers. Pole figures from measurements of experimentally deformed standard samples of calcite and quartzite with a known history of deformation provide information about deformation mechanisms and their temperature/strain history. This information can be applied to interpret preferred orientation of naturally deformed rocks

  4. Target Choice and Unique Synergies in Global Mobile Telephony

    DEFF Research Database (Denmark)

    Claussen, Jörg; Köhler, Rebecca; Kretschmer, Tobias

    2018-01-01

    their foresight to select specific targets: First, they lower integration costs by selecting geographically close targets. This effect is stronger when buyer and target are in the same country, but only if the market is not so concentrated that it provokes regulatory interventions. Second, they select targets......The success of acquisitions rests on detecting and realizing unique synergies between buyer and target through their dyadic relationships. We study the role of unique dyad-specific synergies in the selection of takeover targets in the global mobile telecommunications industry. Firms use...... that can be acquired at a modest bid premium because they have asymmetric bargaining power. Finally, they select targets which can generate significant synergies due to technological synergies. Our work expands the existing target selection literature by studying dyad-specific factors within a single...

  5. Unique Migraine Subtypes, Rare Headache Disorders, and Other Disturbances.

    Science.gov (United States)

    Goadsby, Peter J

    2015-08-01

    The medical aphorism that common things happen commonly makes unique (and less common) migraine subtypes especially appropriate to review for the general neurologist. This article also identifies some rare headache disorders and other disturbances, and offers strategies to manage them. This article discusses migraine with brainstem aura, which is troublesome clinically and has had a change in terminology in the International Classification of Headache Disorders, Third Edition, beta version (ICHD-3 beta), and hemiplegic migraine, which is also troublesome in practice. The rare headache disorder hypnic headache and the exploding head syndrome are also discussed. When hypnic headache is recognized, it is eminently treatable, while exploding head syndrome is a benign condition with no reported consequences. Unique migraine subtypes, rare headache disorders, and other disturbances present to neurologists. When recognized, they can often be managed very well, which offers significant benefits to patients and practice satisfaction to neurologists.

  6. Solitary intraosseous neurofibroma: Report of a unique case

    Directory of Open Access Journals (Sweden)

    Sagar Satish Jangam

    2014-01-01

    Full Text Available Neural tumors located centrally in jaw bones are relatively rare compared with soft tissue neurofibromas. Less than 50 cases have been reported in the literature with a predilection for mandible. This article aims to elucidate a unique case of intraosseous neurofibroma of mandible in a 62-year-old edentulous female patient associated with facial asymmetry due to the swelling extending from the right body of mandible to left body of mandible. The uniqueness of this case is related to the age and extensiveness of this lesion. A review of clinical, radiographic, histological, and immunohistochemical features, and the surgical management pertaining to this case are discussed along with a review of the literature.

  7. Unique Approach to Dental Management of Children with Hearing Impairment.

    Science.gov (United States)

    Renahan, Navanith; Varma, R Balagopal; Kumaran, Parvathy; Xavier, Arun M

    2017-01-01

    The number of deaf children has dramatically increased in the past few decades. These children present to the pediatric dentist a unique set of challenges mostly pertaining to the establishment of communication with them. There have been very few attempts in the past to break down these challenges and formulate a strategy on how to manage them effectively. This is a case report of a child who was successfully managed using two different modes of communication. Finally, the advantages and disadvantages are mentioned, and a common strategy incorporating the positives of both the methods has been devised. Renahan N, Varma RB, Kumaran P, Xavier AM. Unique Approach to Dental Management of Children with Hearing Impairment. Int J Clin Pediatr Dent 2017;10(1):107-110.

  8. Concentration and mindfulness meditations: unique forms of consciousness?

    Science.gov (United States)

    Dunn, B R; Hartigan, J A; Mikulas, W L

    1999-09-01

    Electroencephalographic (EEG) recordings from 19 scalp recording sites were used to differentiate among two posited unique forms of mediation, concentration and mindfulness, and a normal relaxation control condition. Analyzes of all traditional frequency bandwidth data (i.e., delta 1-3 Hz; theta, 4-7 Hz; alpha, 8-12 Hz; beta 1, 13-25 Hz; beta 2, 26-32 Hz) showed strong mean amplitude frequency differences between the two meditation conditions and relaxation over numerous cortical sites. Furthermore, significant differences were obtained between concentration and mindfulness states at all bandwidths. Taken together, our results suggest that concentration and mindfulness "meditations" may be unique forms of consciousness and are not merely degrees of a state of relaxation.

  9. On the Existence and Uniqueness of the Scientific Method.

    Science.gov (United States)

    Wagensberg, Jorge

    2014-01-01

    The ultimate utility of science is widely agreed upon: the comprehension of reality. But there is much controversy about what scientific understanding actually means, and how we should proceed in order to gain new scientific understanding. Is there a method for acquiring new scientific knowledge? Is this method unique and universal? There has been no shortage of proposals, but neither has there been a shortage of skeptics about these proposals. This article proffers for discussion a potential scientific method that aspires to be unique and universal and is rooted in the recent and ancient history of scientific thinking. Curiously, conclusions can be inferred from this scientific method that also concern education and the transmission of science to others.

  10. Being and feeling unique: statistical deviance and psychological marginality.

    Science.gov (United States)

    Frable, D E

    1993-03-01

    Two studies tested the hypothesis that people with culturally stigmatized and concealable conditions (e.g., gays, epileptics, juvenile delinquents, and incest victims) would be more likely to feel unique than people with culturally valued or conspicuous conditions (e.g., the physically attractive, the intellectually gifted, the obese, and the facially scarred). In Study 1, culturally stigmatized individuals with concealable conditions were least likely to perceive consensus between their personal preferences and those of others. In Study 2, they were most likely to describe themselves as unique and to make these self-relevant decisions quickly. Marginality is a psychological reality, not just a statistical one, for those with stigmatized and concealable "master status" conditions.

  11. Structure and phase transitions of the 6,6-cyclopropane isomer of C61H2

    International Nuclear Information System (INIS)

    Stetzer, M.R.; Heiney, P.A.; Stephens, P.W.; Dinnebier, R.E.; Zhu, Q.; McGhie, A.R.; Strongin, R.M.; Brandt, B.M.; Smith, A.B. III

    2000-01-01

    We have used x-ray powder diffraction and differential scanning calorimetry to study the crystalline structures and thermal behavior of the 6,6-cyclopropane isomer of C 61 H 2 . At room temperature, the C 61 H 2 cyclopropane molecules, like those of the 6,5-annulene isomer and C 60 O epoxide, are orientationally disordered and crystallize on a face-centered-cubic lattice such that their methylene groups are statistically disordered among the octahedral voids. Unlike 6,5-C 61 H 2 and C 60 O, the low-temperature structure is not Pa3-bar, but rather a low-symmetry orthorhombic lattice in which a≅b< c. The orientational melting takes place via a two-step transition centered around 198-213 K

  12. Uniqueness of rarefaction waves in multidimensional compressible Euler system

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard; Kreml, Ondřej

    2015-01-01

    Roč. 12, č. 3 (2015), s. 489-499 ISSN 0219-8916 R&D Projects: GA ČR GA13-00522S EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : compressible Euler system * uniqueness * rarefaction wave * Riemann problem Subject RIV: BA - General Mathematics Impact factor: 0.556, year: 2015 http://www.worldscientific.com/doi/abs/10.1142/S0219891615500149

  13. Common processes at unique volcanoes – a volcanological conundrum

    OpenAIRE

    Katharine eCashman; Juliet eBiggs

    2014-01-01

    An emerging challenge in modern volcanology is the apparent contradiction between the perception that every volcano is unique, and classification systems based on commonalities among volcano morphology and eruptive style. On the one hand, detailed studies of individual volcanoes show that a single volcano often exhibits similar patterns of behavior over multiple eruptive episodes; this observation has led to the idea that each volcano has its own distinctive pattern of behavior (or “personali...

  14. Social Capital and Institutions in Rural Kenya: Is Machakos Unique?

    OpenAIRE

    Nyangena, Wilfred; Sterner, Thomas

    2008-01-01

    In Eastern Africa, the experience of Machakos has been heavily debated between Malthusians and the more optimistic Boserupians. Machakos was the epitome of overpopulation and resource degradation in the 1950s, but has since thrived. The Boserupians view Machakos as an illustration of how population growth can solve rather than exacerbate the vicious cycle of poverty and resource degradation. The question arises whether Machakos is unique. This study investigates the role of social capital in ...

  15. The Mysteries of Diamonds: Bizarre History, Amazing Properties, Unique Applications

    International Nuclear Information System (INIS)

    Kagan, Harris

    2008-01-01

    Diamonds have been a prized material throughout history. They are scarce and beautiful, wars have been fought over them, and they remain today a symbol of wealth and power. Diamonds also have exceptional physical properties which can lead to unique applications in science. There are now techniques to artificially synthesize diamonds of extraordinarily high quality. In this talk, Professor Kagan will discuss the history of diamonds, their bizarre properties, and their manufacture and use for 21st century science.

  16. CHID: a unique health information and education database.

    OpenAIRE

    Lunin, L F; Stein, R S

    1987-01-01

    The public's growing interest in health information and the health professions' increasing need to locate health education materials can be answered in part by the new Combined Health Information Database (CHID). This unique database focuses on materials and programs in professional and patient education, general health education, and community risk reduction. Accessible through BRS, CHID suggests sources for procuring brochures, pamphlets, articles, and films on community services, programs ...

  17. Uniqueness of Steiner minimal trees on boundaries in general position

    International Nuclear Information System (INIS)

    Ivanov, A O; Tuzhilin, A A

    2006-01-01

    The following result is proved: there exists an open dense subset U of R 2n such that each P element of U (regarded as an enumerated subset of the standard Euclidean plane R 2 ) is spanned by a unique Steiner minimal tree, that is, a shortest non-degenerate network. Several interesting consequences are also obtained: in particular, it is proved that each planar Steiner tree is planar equivalent to a Steiner minimal tree.

  18. The Mysteries of Diamonds: Bizarre History, Amazing Properties, Unique Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kagan, Harris (Ohio State University)

    2008-06-24

    Diamonds have been a prized material throughout history. They are scarce and beautiful, wars have been fought over them, and they remain today a symbol of wealth and power. Diamonds also have exceptional physical properties which can lead to unique applications in science. There are now techniques to artificially synthesize diamonds of extraordinarily high quality. In this talk, Professor Kagan will discuss the history of diamonds, their bizarre properties, and their manufacture and use for 21st century science.

  19. Recurrent intussusception, coeliac disease and cholelithiasis: A unique combination

    Directory of Open Access Journals (Sweden)

    Sinha C

    2007-01-01

    Full Text Available Authors report an 11-month-old female child, who presented with recurrent episodes of colicky abdominal pain and diarrhea. An abdominal ultrasound revealed small bowel intussusception. She was also noted to have a thick walled gall bladder and a solitary gallstone. Further investigations confirmed the diagnosis of coeliac disease. The combination of small bowel intussusception, coeliac disease and cholelithiasis is unique and has not been reported in the literature.

  20. Diophantine and minimal but not uniquely ergodic (almost)

    International Nuclear Information System (INIS)

    Kwapisz, Jaroslaw; Mathison, Mark

    2012-01-01

    We demonstrate that minimal non-uniquely ergodic behaviour can be generated by slowing down a simple harmonic oscillator with diophantine frequency, in contrast with the known examples where the frequency is well approximable by the rationals. The slowing is effected by a singular time change that brings one phase point to rest. The time one-map of the flow has uncountably many invariant measures yet every orbit is dense, with the minor exception of the rest point

  1. On the stability of unique range sets for meromorphic functions

    International Nuclear Information System (INIS)

    Ha Huy Khoai; Nguyen Van Khue

    2003-03-01

    For a set S we construct a complex space Z S such that S is a unique range set for meromorphic functions (URS) if and only if Z S is hyperbolic. A consequence of this result is that the set of URS with n elements (considered as a subset of C n ) is open, and then the small deformations of Yi's and Frank-Reinders' sets are URS. (author)

  2. On the Non-Uniqueness of Sediment Yield

    Science.gov (United States)

    Kim, J.; Ivanov, V. Y.; Fatichi, S.

    2014-12-01

    There has been ample experimental evidence that soil erosion does not necessarily occur at the same rate, given the same amount of rainfall or runoff. Such a non-unique phenomenon has been often referred to in literature as due to 'natural variability'. Our recent study hypothesized that uncertainties in the distribution and properties of a sediment layer can be a potential clue to one of the reasons of the non-unique sediment yield. Specifically, numerical experimentation with a sophisticated two-dimensional model showed that a deposited layer plays two conflicting roles: it can both increase and decrease soil erosion, given the same magnitude of runoff. The difference in erodibilities of the "original, intact soil layer" and the "deposited, loose soil layer" and the composition of soil particles in the underlying layers give rise to the non-uniqueness of the amount of eroded materials. In continuing efforts, we attempt to investigate this phenomenon using a comprehensive the Universal Soil Loss Erosion (USLE) database, that contains data on paired hillslopes that show a high degree of non-uniqueness in the response, even though the hillslopes exhibit the same topography, soil type, rainfall and meteorological forcings, and landuse. An underlying hypothesis of this study is that uncertainties in the distribution of soil substrate prior to a rainfall event lead to low predictability skill, i.e., a stochastically-varying outcome. A large number of simulation cases demonstrating the proposed hypothesis are conducted using a coupled numerical model, tRIBS-VEGGIE-FEaST (Triangulated irregular network - based Real time Integrated Basin Simulator- VEGetation Generator for Interactive Evolution -Flow Erosion and Sediment Transport).

  3. Methanophosphagen: Unique cyclic pyrophosphate isolated from Methanobacterium thermoautotrophicum

    OpenAIRE

    Kanodia, Sushila; Roberts, Mary Fedarko

    1983-01-01

    A unique cyclic pyrophosphate compound has been detected at 10-12 mM intracellular concentration in Methanobacterium thermoautotrophicum by in vivo31P NMR. This compound has been extracted from cells and purified by anion-exchange chromatography. Studies with 1H, 13C, and 31P NMR and fast-atom-bombardment mass spectrometry have identified it as 2,3-cyclopyrophosphoglycerate, an intramolecularly cyclized pyrophosphate of 2,3-diphosphoglycerate. Chemical degradation to 2,3-diphosphoglycerate an...

  4. Uniqueness of Nash equilibria in a quantum Cournot duopoly game

    International Nuclear Information System (INIS)

    Sekiguchi, Yohei; Sakahara, Kiri; Sato, Takashi

    2010-01-01

    A quantum Cournot game whose classical form game has multiple Nash equilibria is examined. Although the classical equilibria fail to be Pareto optimal, the quantum equilibrium exhibits the following two properties: (i) if the measurement of entanglement between strategic variables chosen by the competing firms is sufficiently large, the multiplicity of equilibria vanishes, and (ii) the more strongly the strategic variables are entangled, the more closely the unique equilibrium approaches to the optimal one.

  5. Synthetic Biology of Cyanobacteria: Unique Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Bertram M Berla

    2013-08-01

    Full Text Available Photosynthetic organisms, and especially cyanobacteria, hold great promise as sources of renewably-produced fuels, bulk and specialty chemicals, and nutritional products. Synthetic biology tools can help unlock cyanobacteria’s potential for these functions, but unfortunately tool development for these organisms has lagged behind that for S. cerevisiae and E. coli. While these organisms may in many cases be more difficult to work with as ‘chassis’ strains for synthetic biology than certain heterotrophs, the unique advantages of autotrophs in biotechnology applications as well as the scientific importance of improved understanding of photosynthesis warrant the development of these systems into something akin to a ‘green E. coli’. In this review, we highlight unique challenges and opportunities for development of synthetic biology approaches in cyanobacteria. We review classical and recently developed methods for constructing targeted mutants in various cyanobacterial strains, and offer perspective on what genetic tools might most greatly expand the ability to engineer new functions in such strains. Similarly, we review what genetic parts are most needed for the development of cyanobacterial synthetic biology. Finally, we highlight recent methods to construct genome-scale models of cyanobacterial metabolism and to use those models to measure properties of autotrophic metabolism. Throughout this paper, we discuss some of the unique challenges of a diurnal, autotrophic lifestyle along with how the development of synthetic biology and biotechnology in cyanobacteria must fit within those constraints.

  6. Plastic-casting intrinsic-surface unique identifier (tag)

    International Nuclear Information System (INIS)

    Palm, R.G.; De Volpi, A.

    1995-04-01

    This report describes the development of an authenticated intrinsic-surf ace tagging method for unique- identification of controlled items. Although developed for control of items limited by an arms control treaty, this method has other potential applications to keep track of critical or high-value items. Each tag (unique-identifier) consists of the intrinsic, microscopic surface topography of a small designated area on a controlled item. It is implemented by making a baseline plastic casting of the designated tag area and usually placing a cover (for example, a bar-code label) over this area to protect the surface from environmental alteration. The plastic casting is returned to a laboratory and prepared for high-resolution scanning electron microscope imaging. Several images are digitized and stored for use as a standard for authentication of castings taken during future inspections. Authentication is determined by numerically comparing digital images. Commercially available hardware and software are used for this tag. Tag parameters are optimized, so unique casting images are obtained from original surfaces, and images obtained from attempted duplicate surfaces are detected. This optimization uses the modulation transfer function, a first principle of image analysis, to determine the parameters. Surface duplication experiments confirmed the optimization

  7. A unique tripartite collision tumor of the esophagus

    Science.gov (United States)

    Schizas, Dimitrios; Michalinos, Adamantios; Alexandrou, Paraskevi; Moris, Demetrios; Baliou, Evangelia; Tsilimigras, Diamantis; Throupis, Theodore; Liakakos, Theodore

    2017-01-01

    Abstract Rationale: We report a unique case of a tripartite esophageal collision tumor consisting of three separate histologic types. Patients concerns: Therapeutic dilemmas on the proper treatment of those rare neoplasms remain unanswered considering both proper surgical therapy and adjuvant therapy. Diagnose: In this paper, we report a unique case of a patient with a tripartite esophageal collision tumor consisting of a small cell carcinoma, an adenocarcinoma of medium differentiation and a signet ring cell carcinoma. Diagnosis is difficult as clinical presentation of the patient was undistinguishable from other, commoner tumor types. Interventions: The patient's diagnostic and therapeutic course along with available data on the collisions tumor's biological behavior and treatment are briefly discussed. Outcomes: Esophagectomy is the best treatment options for these patients. Unique nature of this tumor demands aggresive oncologic treatment. Lessons: Collision tumors are rare neoplasms consisting of distinct cell populations developing in juxtaposition to one another without any areas of intermingling. Various cell types can be found. However, collision neoplasms of the esophagus combining adenomatous and neuroendocrine components are exceedingly rare, with only 5 cases described to date in the literature. Given their rarity, limited information is available on their tumorigenesis, biological behavior and clinical course. In general, these tumors are aggressive neoplasms and significantly affect patient treatment and prognosis. PMID:29245236

  8. Uniqueness of the gauge invariant action for cosmological perturbations

    International Nuclear Information System (INIS)

    Prokopec, Tomislav; Weenink, Jan

    2012-01-01

    In second order perturbation theory different definitions are known of gauge invariant perturbations in single field inflationary models. Consequently the corresponding gauge invariant cubic actions do not have the same form. Here we show that the cubic action for one choice of gauge invariant variables is unique in the following sense: the action for any other, non-linearly related variable can be brought to the same bulk action, plus additional boundary terms. These boundary terms correspond to the choice of hypersurface and generate extra, disconnected contributions to the bispectrum. We also discuss uniqueness of the action with respect to conformal frames. When expressed in terms of the gauge invariant curvature perturbation on uniform field hypersurfaces the action for cosmological perturbations has a unique form, independent of the original Einstein or Jordan frame. Crucial is that the gauge invariant comoving curvature perturbation is frame independent, which makes it extremely helpful in showing the quantum equivalence of the two frames, and therefore in calculating quantum effects in nonminimally coupled theories such as Higgs inflation

  9. Evolutionary theory, human uniqueness and the image of God

    Directory of Open Access Journals (Sweden)

    Gijsbert van den Brink

    2012-10-01

    Full Text Available In this article, I examined what might be called the evolutionary argument against human uniqueness and human dignity. After having rehearsed briefly the roots of the classical Judeo- Christian view on human uniqueness and human dignity in the first chapters of Genesis, I went on to explore and delineate the nature of the evolutionary argument against this view. Next, I examined whether Christian theology might widen the concept of imago Dei so as to include other beings as well as humans, thus giving up the idea of human uniqueness. I concluded, however, that this move is deeply problematic. Therefore, I turned to a discussion of some recent attempts to define both human uniqueness and the image of God in theological rather than empirical terms. One of these, which is based on the concept of incarnation, is found wanting, but another one is construed in such a way that it enables us to reconcile the idea of human uniqueness as encapsulated in the doctrine of the imago Dei with contemporary evolutionary theory. Thus, this article can be seen as an exercise in bringing classical Christian theology to terms with evolution, further highlighting this theology’s ongoing vitality. Evolusieteorie, menslike uniekheid and die beeld van God. In hierdie artikel ondersoek ek die sogenaamde evolusionêre argument teen menslike uniekheid en menswaardigheid. Na ‘n kort oorsig oor die oorsprong van die klassieke Joods-Christelike siening van menslike uniekheid en menswaardigheid soos uit die eerste vyf hoofstukke van Genesis blyk, ondersoek en beeld ek die aard van die evolusionêre argument hierteenoor uit. Vervolgens word die vraag ondersoek of die Christelike teologie die konsep van imago Dei sodanig kan verbreed dat dit ook ander wesens behalwe mense kan insluit, waardeur die idee van menslike uniekheid dus prysgegee word. Ek kom egter tot die slotsom dat hierdie skuif hoogs problematies is. Daarom wend ek my tot ’n bespreking van onlangse pogings om

  10. Unique Chiral Interpenetrating d-f Heterometallic MOFs as Luminescent Sensors.

    Science.gov (United States)

    Wu, Zhi-Lei; Dong, Jie; Ni, Wei-Yan; Zhang, Bo-Wen; Cui, Jian-Zhong; Zhao, Bin

    2015-06-01

    One novel three-dimensional (3D) 3d-4f metal-organic framework (MOF), [TbZn(L)(CO3)2(H2O)]n (1) [HL = 4'-(4-carboxyphenyl)-2,2':6',2″-terpyridine], has been successfully synthesized and structurally characterized. Structural analysis shows that compound 1 features a unique chiral interpenetrating 3D framework for the first time. The resulting crystals of 1 are composed of enantiomers 1a (P41) and 1b (P43), as was clearly confirmed by the crystal structure and the corresponding circular dichroism (CD) analyses of eight randomly selected crystals. The investigations on CD spectra based on every single crystal clearly assigned the Cotton effect signals. The powder X-ray diffraction measurement of 1 after being immersed in common solvents reveals that 1 possess excellent solvent stability. Furthermore, luminescent studies imply that 1 displays highly selective luminescent sensing of aldehydes, such as formol, acetaldehyde, and propanal.

  11. Structure of as cast L12 compounds in Al3Zr-base alloys containing Cu and Mn

    International Nuclear Information System (INIS)

    Virk, I.S.; Varin, R.A.

    1991-01-01

    It was first shown that the low symmetry, tetragonal DO 23 crystal structure of Al 3 Zr intermetallic can be changed to the related cubic L1 2 crystal structure by alloying with Ni (Al 5 NiZr 2 ) and Cu(Al 5 CuZr 2 ). It has been reported that previous work has successfully modified Al 3 Zr with Fe, Cu, Cr and Ni obtaining nearly single phase materials with L1 2 structure. However, they only studied the microstructure and mechanical properties of Fe - modified intermetallic (Al-6at% Fe-25at% Zr). The purpose of the paper is to describe and interpret experimental observations on the microstructure of Al 5 CuZr 2 and Al 66 Mn 9 Zr 25 (at.%) modifications of base Al 3 Zr intermetallic. The one modified with Mn has not been reported in literature although its Al 3 Ti - base counterpart has recently been successfully produced (3, 4)

  12. Botulinum neurotoxin: unique folding of enzyme domain of the most-poisonous poison.

    Science.gov (United States)

    Kumar, Raj; Kukreja, Roshan V; Li, Li; Zhmurov, Artem; Kononova, Olga; Cai, Shuowei; Ahmed, Syed A; Barsegov, Valeri; Singh, Bal Ram

    2014-01-01

    Botulinum neurotoxin (BoNT), the most toxic substance known to mankind, is the first example of the fully active molten globule state. To understand its folding mechanism, we performed urea denaturation experiments and theoretical modeling using BoNT serotype A (BoNT/A). We found that the extent of BoNT/A denaturation from the native state (N) shows a nonmonotonic dependence on urea concentration indicating a unique multistep denaturation process, N → I1 [Formula: see text] I2 [Formula: see text] U, with two intermediate states I1 and I2. BoNT/A loses almost all its secondary structure in 3.75 M urea (I1), yet it displays a native-like secondary structure in 5 M urea (I2). This agrees with the results of theoretical modeling, which helped to determine the molecular basis of unique behavior of BoNT/A in solution. Except for I2, all the states revert back to full enzymatic activity for SNAP-25 including the unfolded state U stable in 7 M urea. Our results stress the importance of structural flexibility in the toxin's mechanism of survival and action, an unmatched evolutionary trait from billion-year-old bacteria, which also correlates with the long-lasting enzymatic activity of BoNT inside neuronal cells. BoNT/A provides a rich model to explore protein folding in relation to functional activity.

  13. A Layer Framework to Investigate Student Understanding and Application of the Existence and Uniqueness Theorems of Differential Equations

    Science.gov (United States)

    Raychaudhuri, D.

    2007-01-01

    The focus of this paper is on student interpretation and usage of the existence and uniqueness theorems for first-order ordinary differential equations. The inherent structure of the theorems is made explicit by the introduction of a framework of layers concepts-conditions-connectives-conclusions, and we discuss the manners in which students'…

  14. ROMANIA'S MACROECONOMIC ACHIEVEMENTS FOR JOINING THE UNIQUE EUROPEAN CURENCY

    Directory of Open Access Journals (Sweden)

    SILVIA POPESCU

    2011-04-01

    Full Text Available The Romanian government has announced plans to join the eurozone by 2015. Currently, the leu is not yet part of ERM II but plans to join in 2010-2012. The economic advantages of the monetary union grow with expansion of the Euro zone. There is also a high level of skepticism; the main fear about the Euro is the inflation –that is considerable promoted by the Euro currency’s exchange rate in comparison with 2002; another restraint is due to member states inability to establish their own interest rates. The IMF arose the option of joining the Euro zone criteria relaxing. A one-sided Euro’s joining was suggested by International Monetary Fund on March-April 2009, in a confidential report mentioned by The Financial Times as the emergent states in Central and Eastern Europe to be able to pass to the unique currency, but not being represented in the Central European Bank Board. By its side, CEB considers that emergent states of the European Union must not pass to the unique currency unilaterally, because such a fact could under-mine the trust in Euro currency worldwide. This option would hardly deepen the macroeconomic controversies inside the Euro zone and would contradict the previous conditions already imposed. An acceptable solution could be the fastening of emergent countries joining the Exchange Rate Mechanism 2, after they are aware of risks arisen by such a step. The European Commission endorses in the Convergence Report on 2010 that Romania doesn’t meet any criteria needed by passing to the unique European currency, respectively: prices stability; budget position of the government; stability of exchange rate; interest convergence on long run and there are also law impediments. Our paper discusses arguments for a faster passing to the Euro currency versus arguments for a late joining the Euro currency in Romania.

  15. Unique expression of cytoskeletal proteins in human soft palate muscles.

    Science.gov (United States)

    Shah, Farhan; Berggren, Diana; Holmlund, Thorbjörn; Levring Jäghagen, Eva; Stål, Per

    2016-03-01

    The human oropharyngeal muscles have a unique anatomy with diverse and intricate functions. To investigate if this specialization is also reflected in the cytoarchitecture of muscle fibers, intermediate filament proteins and the dystrophin-associated protein complex have been analyzed in two human palate muscles, musculus uvula (UV) and musculus palatopharyngeus (PP), with immunohistochenmical and morphological techniques. Human limb muscles were used as reference. The findings show that the soft palate muscle fibers have a cytoskeletal architecture that differs from the limb muscles. While all limb muscles showed immunoreaction for a panel of antibodies directed against different domains of cytoskeletal proteins desmin and dystrophin, a subpopulation of palate muscle fibers lacked or had a faint immunoreaction for desmin (UV 11.7% and PP 9.8%) and the C-terminal of the dystrophin molecule (UV 4.2% and PP 6.4%). The vast majority of these fibers expressed slow contractile protein myosin heavy chain I. Furthermore, an unusual staining pattern was also observed in these fibers for β-dystroglycan, caveolin-3 and neuronal nitric oxide synthase nNOS, which are all membrane-linking proteins associated with the dystrophin C-terminus. While the immunoreaction for nNOS was generally weak or absent, β-dystroglycan and caveolin-3 showed a stronger immunostaining. The absence or a low expression of cytoskeletal proteins otherwise considered ubiquitous and important for integration and contraction of muscle cells indicate a unique cytoarchitecture designed to meet the intricate demands of the upper airway muscles. It can be concluded that a subgroup of muscle fibers in the human soft palate appears to have special biomechanical properties, and their unique cytoarchitecture must be taken into account while assessing function and pathology in oropharyngeal muscles. © 2015 Anatomical Society.

  16. Unique encoding for streamline topologies of incompressible and inviscid flows in multiply connected domains

    Energy Technology Data Exchange (ETDEWEB)

    Sakajo, T [Department of Mathematics, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Sawamura, Y; Yokoyama, T, E-mail: sakajo@math.kyoto-u.ac.jp [JST CREST, Kawaguchi, Saitama 332-0012 (Japan)

    2014-06-01

    This study considers the flow of incompressible and inviscid fluid in two-dimensional multiply connected domains. For such flows, encoding algorithms to assign a unique sequence of words to any structurally stable streamline topology based on the theory presented by Yokoyama and Sakajo (2013 Proc. R. Soc. A 469 20120558) are proposed. As an application, we utilize the algorithms to characterize the evolution of an incompressible and viscid flow around a flat plate inclined to the uniform flow in terms of the change of the word representations for their instantaneous streamline topologies. (papers)

  17. Unique Association of Rare Cardiovascular Disease in an Athlete With Ventricular Arrhythmias.

    Science.gov (United States)

    Santomauro, V; Contursi, M; Dellegrottaglie, S; Borsellino, G

    2015-01-01

    Ventricular arrhythmias are a leading cause of non-elegibility to competitive sport. The failure to detect a significant organic substrate in the initial stage of screening does not preclude the identification of structural pathologies in the follow-up by using advanced imaging techniques. Here we report the case of a senior athlete judged not elegible because an arrhythmia with the morphology consistent with the origin of the left ventricle, in which subsequent execution of a cardiac MR and a thoracic CT scan has allowed the identification of an unique association between an area of myocardial damage, probable site of origine of the arrhythma, and a rare aortic malformation.

  18. A natural language processing pipeline for pairing measurements uniquely across free-text CT reports.

    Science.gov (United States)

    Sevenster, Merlijn; Bozeman, Jeffrey; Cowhy, Andrea; Trost, William

    2015-02-01

    To standardize and objectivize treatment response assessment in oncology, guidelines have been proposed that are driven by radiological measurements, which are typically communicated in free-text reports defying automated processing. We study through inter-annotator agreement and natural language processing (NLP) algorithm development the task of pairing measurements that quantify the same finding across consecutive radiology reports, such that each measurement is paired with at most one other ("partial uniqueness"). Ground truth is created based on 283 abdomen and 311 chest CT reports of 50 patients each. A pre-processing engine segments reports and extracts measurements. Thirteen features are developed based on volumetric similarity between measurements, semantic similarity between their respective narrative contexts and structural properties of their report positions. A Random Forest classifier (RF) integrates all features. A "mutual best match" (MBM) post-processor ensures partial uniqueness. In an end-to-end evaluation, RF has precision 0.841, recall 0.807, F-measure 0.824 and AUC 0.971; with MBM, which performs above chance level (P0.960) indicates that the task is well defined. Domain properties and inter-section differences are discussed to explain superior performance in abdomen. Enforcing partial uniqueness has mixed but minor effects on performance. A combined machine learning-filtering approach is proposed for pairing measurements, which can support prospective (supporting treatment response assessment) and retrospective purposes (data mining). Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Dirac fields in flat FLRW cosmology: Uniqueness of the Fock quantization

    Energy Technology Data Exchange (ETDEWEB)

    Cortez, Jerónimo, E-mail: jacq@ciencias.unam.mx [Departamento de Física, Facultad de Ciencias, Universidad Nacional Autónoma de México, México D.F. 04510 (Mexico); Elizaga Navascués, Beatriz, E-mail: beatriz.elizaga@iem.cfmac.csic.es [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid (Spain); Martín-Benito, Mercedes, E-mail: m.martin@hef.ru.nl [Radboud University Nijmegen, Institute for Mathematics, Astrophysics and Particle Physics, Heyendaalseweg 135, NL-6525 AJ Nijmegen (Netherlands); Mena Marugán, Guillermo A., E-mail: mena@iem.cfmac.csic.es [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid (Spain); Velhinho, José M., E-mail: jvelhi@ubi.pt [Universidade da Beira Interior, Rua Marquês d’Ávila e Bolama, 6201-001, Covilhã (Portugal)

    2017-01-15

    We address the issue of the infinite ambiguity that affects the construction of a Fock quantization of a Dirac field propagating in a cosmological spacetime with flat compact sections. In particular, we discuss a physical criterion that restricts to a unique possibility (up to unitary equivalence) the infinite set of available vacua. We prove that this desired uniqueness is guaranteed, for any possible choice of spin structure on the spatial sections, if we impose two conditions. The first one is that the symmetries of the classical system must be implemented quantum mechanically, so that the vacuum is invariant under the symmetry transformations. The second and more important condition is that the constructed theory must have a quantum dynamics that is implementable as a (non-trivial) unitary operator in Fock space. Actually, this unitarity of the quantum dynamics leads us to identify as explicitly time dependent some very specific contributions of the Dirac field. In doing that, we essentially characterize the part of the dynamics governed by the Dirac equation that is unitarily implementable. The uniqueness of the Fock vacuum is attained then once a physically motivated convention for the concepts of particles and antiparticles is fixed.

  20. Dirac fields in flat FLRW cosmology: Uniqueness of the Fock quantization

    International Nuclear Information System (INIS)

    Cortez, Jerónimo; Elizaga Navascués, Beatriz; Martín-Benito, Mercedes; Mena Marugán, Guillermo A.; Velhinho, José M.

    2017-01-01

    We address the issue of the infinite ambiguity that affects the construction of a Fock quantization of a Dirac field propagating in a cosmological spacetime with flat compact sections. In particular, we discuss a physical criterion that restricts to a unique possibility (up to unitary equivalence) the infinite set of available vacua. We prove that this desired uniqueness is guaranteed, for any possible choice of spin structure on the spatial sections, if we impose two conditions. The first one is that the symmetries of the classical system must be implemented quantum mechanically, so that the vacuum is invariant under the symmetry transformations. The second and more important condition is that the constructed theory must have a quantum dynamics that is implementable as a (non-trivial) unitary operator in Fock space. Actually, this unitarity of the quantum dynamics leads us to identify as explicitly time dependent some very specific contributions of the Dirac field. In doing that, we essentially characterize the part of the dynamics governed by the Dirac equation that is unitarily implementable. The uniqueness of the Fock vacuum is attained then once a physically motivated convention for the concepts of particles and antiparticles is fixed.

  1. Seafloor massive sulfide deposits support unique megafaunal assemblages: Implications for seabed mining and conservation.

    Science.gov (United States)

    Boschen, Rachel E; Rowden, Ashley A; Clark, Malcolm R; Pallentin, Arne; Gardner, Jonathan P A

    2016-04-01

    Mining of seafloor massive sulfides (SMS) is imminent, but the ecology of assemblages at SMS deposits is poorly known. Proposed conservation strategies include protected areas to preserve biodiversity at risk from mining impacts. Determining site suitability requires biological characterisation of the mine site and protected area(s). Video survey of a proposed mine site and protected area off New Zealand revealed unique megafaunal assemblages at the mine site. Significant relationships were identified between assemblage structure and environmental conditions, including hydrothermal features. Unique assemblages occurred at both active and inactive chimneys and are particularly at risk from mining-related impacts. The occurrence of unique assemblages at the mine site suggests that the proposed protected area is insufficient alone and should instead form part of a network. These results provide support for including hydrothermally active and inactive features within networks of protected areas and emphasise the need for quantitative survey data of proposed sites. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Spot Pricing When Lagrange Multipliers Are Not Unique

    DEFF Research Database (Denmark)

    Feng, Donghan; Xu, Zhao; Zhong, Jin

    2012-01-01

    Classical spot pricing theory is based on multipliers of the primal problem of an optimal market dispatch, i.e., the solution of the dual problem. However, the dual problem of market dispatch may yield multiple solutions. In these circumstances, spot pricing or any standard pricing practice based...... on a strict extension of the principles of spot pricing and surplus allocation, we propose a new pricing methodology that can yield unique, impartial, and robust solution. The new method has been analyzed and compared with other pricing approaches in accordance with spot pricing theory. Case studies support...

  3. Existence and uniqueness in anisotropic conductivity reconstruction with Faraday's law

    KAUST Repository

    Lee, Min-Gi

    2015-03-18

    We show that three sets of internal current densities are the right amount of data that give the existence and the uniqueness at the same time in reconstructing an anisotropic conductivity in two space dimensions. The curl free equation of Faraday’s law is taken instead of the usual divergence free equation of the electrical impedance to- mography. Boundary conditions related to given current densities are introduced which complete a well determined problem for conductivity reconstruction together with Fara- day’s law.

  4. Review of the book: MUPO Program. Unique Minds

    Directory of Open Access Journals (Sweden)

    José Luis Rodríguez-Arias

    2017-07-01

    Full Text Available Unique Minds (Mentes Únicas and its version for teachers and counsellors, MUPO, are programs full of good ideas and tools for teachers and families. Both programs help to address learning disabilities in the natural context in which they take place and help children, families and teachers in their search for solutions based on their own resources. The programs are grounded on General Systems Theory and Multiple Intelligences Theory. They accessibly explain how our brain works and use techniques from Systemic Brief Family Therapy, such as Externalization, especially appropriate for the target ages - 8 to 12 years old, the ages when children learn to learn-.

  5. Uniqueness of solution to a stationary boundary kinetic problem

    International Nuclear Information System (INIS)

    Zhykharsky, A.V.

    1992-01-01

    The paper treats the question of uniqueness of solution to the boundary kinetic problem. This analysis is based on the accurate solutions to the stationary one-dimensional boundary kinetic problem for the limited plasma system. In the paper a simplified problem statement is used (no account is taken of the external magnetic field, a simplest form of boundary conditions is accepted) which, however, covers all features of the problem considered. Omitting the details of the conclusion we will write a set of Vlasov stationary kinetic equations for the cases of plane, cylindrical and spherical geometry of the problem. (author) 1 ref

  6. Bilateral Morgagni Hernia: A Unique Presentation of a Rare Pathology

    Directory of Open Access Journals (Sweden)

    Michael Leshen

    2016-01-01

    Full Text Available Morgagni hernia is an unusual congenital herniation of abdominal content through the triangular parasternal gaps of the anterior diaphragm. They are commonly asymptomatic and right-sided. We present a case of a bilateral Morgagni hernia resulting in delayed growth in a 10-month-old boy. The presentation was unique due to its bilateral nature and its symptomatic compression of the mediastinum. Diagnosis was made by 3D reconstructed CT angiogram. The patient underwent medical optimization until he was safely able to tolerate laparoscopic surgical repair of his hernia. Upon laparoscopy, the CT findings were confirmed and the hernia was repaired.

  7. Unique molecular properties of superoxide dismutase from teleost fish skin.

    Science.gov (United States)

    Nakano, T; Sato, M; Takeuchi, M

    1995-02-27

    A unique Cu,Zn-SOD was found and isolated from plaice Paralichthys olivaceus skin. Surprisingly, the properties of purified fish skin SOD were very different from those of SOD from other sources reported so far. The purified SOD was composed of four same subunits of 16 kDa and the molecular weight of the native SOD was found to be around 65 kDa. The dominant amino acids of the SOD were Ser, Thr, Pro and Glu. Above 70 degrees C, thermostability of the SOD was much lower than that of bovine erythrocyte Cu,Zn-SOD.

  8. Protostylid: As never reported before! A unique case with variation

    Directory of Open Access Journals (Sweden)

    Vela D Desai

    2016-01-01

    Full Text Available Human jaw and teeth display a high degree of morphological individuality as they represent personal, familial, and population characteristics and one among them are cuspal variations. A protostylid is a supernumerary or accessory cusp located on the mesiobuccal surface of the mandibular molars that seldom pose problems. A forensic odontologist may find significant interest in its classification and identification among victims of mass causalties and bite marks on living and nonliving objects. The authors here are reporting a case of protostylid with a unique presentation which, to best of our knowledge is not reported so far.

  9. Explaining human uniqueness: genome interactions with environment, behaviour and culture.

    Science.gov (United States)

    Varki, Ajit; Geschwind, Daniel H; Eichler, Evan E

    2008-10-01

    What makes us human? Specialists in each discipline respond through the lens of their own expertise. In fact, 'anthropogeny' (explaining the origin of humans) requires a transdisciplinary approach that eschews such barriers. Here we take a genomic and genetic perspective towards molecular variation, explore systems analysis of gene expression and discuss an organ-systems approach. Rejecting any 'genes versus environment' dichotomy, we then consider genome interactions with environment, behaviour and culture, finally speculating that aspects of human uniqueness arose because of a primate evolutionary trend towards increasing and irreversible dependence on learned behaviours and culture - perhaps relaxing allowable thresholds for large-scale genomic diversity.

  10. Unique case of a geminated supernumerary tooth with trifid crown

    International Nuclear Information System (INIS)

    Ather, Amber; Ather, Hunaiza; Sheth, Sanket Milan; Muliya, Vidya Saraswathi

    2012-01-01

    Gemination, a relatively uncommon dental anomaly, is characterized by its peculiar representation as a tooth with a bifid crown and a common root and root canal. It usually occurs in primary dentition. To come across gemination in a supernumerary tooth is a rare phenomenon. The purpose of this paper is to present a unique case of hyperdontia wherein gemination in an impacted supernumerary tooth resulted in a trifid crown unlike the usual bifid crown. The role of conventional radiographs as well as computed tomography, to accurately determine the morphology and spatial location, and to arrive at a diagnosis, is also emphasized in this paper.

  11. Granulomatous slack skin syndrome: Report of a unique case.

    Science.gov (United States)

    Maheswari, S Uma; Sampath, V; Ramesh, A

    2018-01-01

    Granulomatous slack skin syndrome is a rare variant of cutaneous T-cell lymphoma (mycosis fungoides). It is characterized clinically by redundant skin folds, which show a predilection towards flexural areas such as the axilla and the groin. Histologically, it shows a granulomatous T-cell infiltrate and loss of elastic tissue. It has an indolent but progressive course; and is usually refractory to treatment. We report a unique case of slack skin syndrome, sparing the classical sites with rapid and unusual involvement of non-intertriginous areas.

  12. Unique cerebrovascular anomalies in Noonan syndrome with RAF1 mutation.

    Science.gov (United States)

    Zarate, Yuri A; Lichty, Angie W; Champion, Kristen J; Clarkson, L Kate; Holden, Kenton R; Matheus, M Gisele

    2014-08-01

    Noonan syndrome is a common autosomal dominant neurodevelopmental disorder caused by gain-of-function germline mutations affecting components of the Ras-MAPK pathway. The authors present the case of a 6-year-old male with Noonan syndrome, Chiari malformation type I, shunted benign external hydrocephalus in infancy, and unique cerebrovascular changes. A de novo heterozygous change in the RAF1 gene was identified. The patient underwent brain magnetic resonance imaging, computed tomography angiography, and magnetic resonance angiography to further clarify the nature of his abnormal brain vasculature. The authors compared his findings to the few cases of Noonan syndrome reported with cerebrovascular pathology. © The Author(s) 2013.

  13. Introducing COSS: A new and unique oil spill research facility

    International Nuclear Information System (INIS)

    Kitchen, R. B.; Bonner, J. S.; Autenrieth, R. L.; Donnelly, K. C.; Ernest, A. N. S.

    1997-01-01

    A new oil spill research facility in Corpus Christi, Texas began operation in April 1997 to address the appropriate use, application and effectiveness of chemical, physical and biological oil spill response agents. The Coastal Oil Spill Simulation (COSS) facility consists of nine meso scale wave tanks and will offer to science and industry a unique opportunity to spill oil in a controlled environment and to study fate, transport and remediation of oil releases in simulated coastal, intertidal, lagunal, channel and porous media. 1 ref

  14. Electrical Burn Causing a Unique Pattern of Neurological Injury

    Directory of Open Access Journals (Sweden)

    Nathan R. Schaefer, BExSc, MBBS (Hons

    2015-04-01

    Full Text Available Summary: Neurological involvement is not uncommon in patients who sustain electrical injury. The exact mechanism of nervous system damage following electrical trauma is not fully understood. The gamut of possible neurologic manifestations following electrical injury is diverse. This case report describes a young man with a unique pattern of neurological injury following an electrical burn. The combination of brachial plexopathy, partial Horner’s syndrome, and phrenic nerve palsy secondary to electrical injury has not been previously described in the literature.

  15. Uniqueness of KMS states for continuous fermion systems

    International Nuclear Information System (INIS)

    Jaekel, C.D.

    1993-01-01

    In 1989 Prof H. Narnhofer and Prof. W. Thirring established a (nonlocal) model of fermions with pair interactions. The existence of equilibrium states and the appearance of mixing properties was proofed. If this model reflects the basic facts of nature, one has to expect and to require that at high temperatures there is a unique equilibrium state and at low temperatures there are many different equilibrium states. Uniqueness of the equilibrium state at high temperatures is the topic of this dissertation. One may be astonished, that the proof of the uniqueness requires such a huge machinery, while the existence of KMS-states followes from fairly general conditions. Two states differ, if they can be distinguished by experiment. If one considers now that we have to show that two KMS-states at high temperatures result into the same value in all experiments one can think of, one might get an idea how unhandy this problem is. Even a conscious numeration of all experiments was a problem. Surprisingly only a few principal ideas of the treatment of spin-models survive. The temperature is the leading parameter and therefore it is a good idea to make a high temperature perturbation expansion for the KMS-condition, which fixes an equilibrium state in mathematical terms. But when we choose a generating vector for the perturbation expansion the similarities end. We better use physical considerations: at high temperatures we expect that chemical bounds will be broken up and the interacting equilibrium state will differ only slightly from the equilibrium state for the free time evolution. Roughly spoken, one can expect that high-energetic particles neglect interactions and fly in a straight line. In chapter 2.4 the whole machinery is presented in an easy-to-survey manner on a simple interaction. But in the case of pair interactions every particle interacts with each other and so the author was not able to find an easily accessible form of the developed method for this case

  16. Space - A unique environment for process modeling R&D

    Science.gov (United States)

    Overfelt, Tony

    1991-01-01

    Process modeling, the application of advanced computational techniques to simulate real processes as they occur in regular use, e.g., welding, casting and semiconductor crystal growth, is discussed. Using the low-gravity environment of space will accelerate the technical validation of the procedures and enable extremely accurate determinations of the many necessary thermophysical properties. Attention is given to NASA's centers for the commercial development of space; joint ventures of universities, industries, and goverment agencies to study the unique attributes of space that offer potential for applied R&D and eventual commercial exploitation.

  17. Lafora disease offers a unique window into neuronal glycogen metabolism.

    Science.gov (United States)

    Gentry, Matthew S; Guinovart, Joan J; Minassian, Berge A; Roach, Peter J; Serratosa, Jose M

    2018-05-11

    Lafora disease (LD) is a fatal, autosomal recessive, glycogen-storage disorder that manifests as severe epilepsy. LD results from mutations in the gene encoding either the glycogen phosphatase laforin or the E3 ubiquitin ligase malin. Individuals with LD develop cytoplasmic, aberrant glycogen inclusions in nearly all tissues that more closely resemble plant starch than human glycogen. This Minireview discusses the unique window into glycogen metabolism that LD research offers. It also highlights recent discoveries, including that glycogen contains covalently bound phosphate and that neurons synthesize glycogen and express both glycogen synthase and glycogen phosphorylase. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Selenoproteins-What unique properties can arise with selenocysteine in place of cysteine?

    Science.gov (United States)

    Arnér, Elias S J

    2010-05-01

    The defining entity of a selenoprotein is the inclusion of at least one selenocysteine (Sec) residue in its sequence. Sec, the 21st naturally occurring genetically encoded amino acid, differs from its significantly more common structural analog cysteine (Cys) by the identity of a single atom: Sec contains selenium instead of the sulfur found in Cys. Selenium clearly has unique chemical properties that differ from sulfur, but more striking are perhaps the similarities between the two elements. Selenium was discovered by Jöns Jacob Berzelius, a renowned Swedish scientist instrumental in establishing the institution that would become Karolinska Institutet. Written at the occasion of the bicentennial anniversary of Karolinska Institutet, this mini review focuses on the unique selenium-derived properties that may potentially arise in a protein upon the inclusion of Sec in place of Cys. With 25 human genes encoding selenoproteins and in total several thousand selenoproteins yet described in nature, it seems likely that the presence of that single selenium atom of Sec should convey some specific feature, thereby explaining the existence of selenoproteins in spite of demanding and energetically costly Sec-specific synthesis machineries. Nonetheless, most, if not all, of the currently known selenoproteins are also found as Cys-containing non-selenoprotein orthologues in other organisms, wherefore any potentially unique properties of selenoproteins are yet a matter of debate. The pK(a) of free Sec (approximately 5.2) being significantly lower than that of free Cys (approximately 8.5) has often been proposed as one of the unique features of Sec. However, as discussed herein, this pK(a) difference between Sec and Cys can hardly provide an evolutionary pressure for maintenance of selenoproteins. Moreover, the typically 10- to 100-fold lower enzymatic efficiencies of Sec-to-Cys mutants of selenoprotein oxidoreductases, are also weak arguments for the overall existence of

  19. Unique Perspectives on a Transforming Energy Economy: 2014 Annual Report (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    Gossett, S. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-03-01

    What makes JISEA unique? Unique perspectives. This brochure highlights the unique perspectives provided by the Joint Institute for Strategic Energy Analysis through JISEA's recent accomplishments and the people behind them.

  20. Human behavior. Sex equality can explain the unique social structure of hunter-gatherer bands.

    Science.gov (United States)

    Dyble, M; Salali, G D; Chaudhary, N; Page, A; Smith, D; Thompson, J; Vinicius, L; Mace, R; Migliano, A B

    2015-05-15

    The social organization of mobile hunter-gatherers has several derived features, including low within-camp relatedness and fluid meta-groups. Although these features have been proposed to have provided the selective context for the evolution of human hypercooperation and cumulative culture, how such a distinctive social system may have emerged remains unclear. We present an agent-based model suggesting that, even if all individuals in a community seek to live with as many kin as possible, within-camp relatedness is reduced if men and women have equal influence in selecting camp members. Our model closely approximates observed patterns of co-residence among Agta and Mbendjele BaYaka hunter-gatherers. Our results suggest that pair-bonding and increased sex egalitarianism in human evolutionary history may have had a transformative effect on human social organization. Copyright © 2015, American Association for the Advancement of Science.

  1. Existence and uniqueness of the maximum likelihood estimator for models with a Kronecker product covariance structure

    NARCIS (Netherlands)

    Ros, B.P.; Bijma, F.; de Munck, J.C.; de Gunst, M.C.M.

    2016-01-01

    This paper deals with multivariate Gaussian models for which the covariance matrix is a Kronecker product of two matrices. We consider maximum likelihood estimation of the model parameters, in particular of the covariance matrix. There is no explicit expression for the maximum likelihood estimator

  2. Unique mitochondrial genome structure in diplonemids, the sister group of kinetoplastids

    Czech Academy of Sciences Publication Activity Database

    Marande, W.; Lukeš, Julius; Burger, G.

    2005-01-01

    Roč. 4, č. 6 (2005), s. 1137-1146 ISSN 1535-9778 R&D Projects: GA AV ČR IAA5022302 Grant - others:Canadian Institutes of Health Research(CA) SP-34; Canadian Institutes of Health Research(CA) MOP-15331 Institutional research plan: CEZ:AV0Z60220518 Keywords : Diplonema * kinetoplast * trans-splicing Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.303, year: 2005

  3. When are Overcomplete Topic Models Identifiable? Uniqueness of Tensor Tucker Decompositions with Structured Sparsity

    Science.gov (United States)

    2013-08-14

    Communications and Computing, Electrical Engineering and Computer Science Dept., University of California, Irvine, USA 92697. Email : a.anandkumar...uci.edu,mjanzami@uci.edu. Daniel Hsu and Sham Kakade are with Microsoft Research New England, 1 Memorial Drive, Cambridge, MA 02142. Email : dahsu...Andreas Maurer, Massimiliano Pontil, and Bernardino Romera-Paredes. Sparse coding for multitask and transfer learning. ArxXiv preprint, abs/1209.0738, 2012

  4. Metaphyseal pattern: Uniqueness of this structure in growing bones originating from cartilaginous anlage

    International Nuclear Information System (INIS)

    Balmain, N.; Moscofian, A.; Cuisinier-Gleizes, P.

    1983-01-01

    Microradiographic examination of metaphyses in long and short tubular growing bones allowed detection of a repetitive, clearly defined pattern of three adjacent zones; the latter are successively formed by the mineralization of cartilaginous longitudinal intercolumnar septa and by the subsequent apposition of other mineralized tissues concurrently with resorption. Consequently, each zone of the metaphysis includes mineralized tissues of various compositions and ages, identifiable by their different mineralization densities. Microradiography of pieces of the growing skeleton in several animal species shows that the same organization is not only present in long and short tubular bones but also in many other such as the pelvis and scapula, cuboid bones like the calcaneum and talus, and cartilaginous bones at the base of the skull. This suggests that there is no difference between the osteogenesis pattern of these bones and tubular ones. The problem of identifying the factors generating such metaphyseal organization is raised. (orig.)

  5. Domain swapping in structure of mNKR-P1A: unique feature with unknown function

    Czech Academy of Sciences Publication Activity Database

    Kolenko, Petr; Rozbeský, Daniel; Skálová, Tereza; Koval, Tomáš; Fejfarová, Karla; Dušková, Jarmila; Stránský, Jan; Hašek, Jindřich; Dohnálek, Jan

    2014-01-01

    Roč. 70, Supplement /August/ (2014), C249 ISSN 0108-7673. [Congress and General Assembly of the International Union of Crystallography /23./ - IUCr 2014. 05.08.2014-12.08.2014, Montreal] R&D Projects: GA MŠk(CZ) EE2.3.30.0029 Institutional support: RVO:61389013 ; RVO:61388971 ; RVO:86652036 Keywords : NK cell * receptor * swapping Subject RIV: CE - Biochemistry

  6. On the non-uniqueness of the nodal mathematical adjoint

    International Nuclear Information System (INIS)

    Müller, Erwin

    2014-01-01

    Highlights: • We evaluate three CMFD schemes for computing the nodal mathematical adjoint. • The nodal mathematical adjoint is not unique and can be non-positive (nonphysical). • Adjoint and forward eigenmodes are compatible if produced by the same CMFD method. • In nodal applications the excited eigenmodes are purely mathematical entities. - Abstract: Computation of the neutron adjoint flux within the framework of modern nodal diffusion methods is often facilitated by reducing the nodal equation system for the forward flux into a simpler coarse-mesh finite-difference form and then transposing the resultant matrix equations. The solution to the transposed problem is known as the nodal mathematical adjoint. Since the coarse-mesh finite-difference reduction of a given nodal formulation can be obtained in a number of ways, different nodal mathematical adjoint solutions can be computed. This non-uniqueness of the nodal mathematical adjoint challenges the credibility of the reduction strategy and demands a verdict as to its suitability in practical applications. This is the matter under consideration in this paper. A selected number of coarse-mesh finite-difference reduction schemes are described and compared. Numerical calculations are utilised to illustrate the differences in the adjoint solutions as well as to appraise the impact on such common applications as the computation of core point kinetics parameters. Recommendations are made for the proper application of the coarse-mesh finite-difference reduction approach to the nodal mathematical adjoint problem

  7. Unique Results and Lessons Learned From the TSS Missions

    Science.gov (United States)

    Stone, Nobie H.

    2016-01-01

    The Tethered Satellite System (TSS) Space Shuttle missions, TSS-1 in 1993 and TSS-1R in 1996, were the height of space tether technology development in the U.S. Altogether, the investment made by NASA and the Italian Space Agency (ASI) over the thirteen-year period of the TSS Program totaled approximately $400M-exclusive of the two Space Shuttle flights provided by NASA. Since those two pioneering missions, there have been several smaller tether flight experiments, but interest in this promising technology has waned within NASA as well as the DOD agencies. This is curious in view of the unique capabilities of space tether systems and the fact that they have been flight validated in earth orbit and shown to perform better than the preflight dynamic or electrodynamic theoretical predictions. While it is true that the TSS-1 and TSS-1R missions experienced technical difficulties, the causes of these early developmental problems are now known to have been engineering design flaws, material selection, and procedural issues that (1) are unrelated to the basic viability of space tether technology, and (2) can be readily corrected. The purpose of this paper is to review the dynamic and electrodynamic fundamentals of space tethers and the unique capabilities they afford (that are enabling to certain types of space missions); to elucidate the nature, cause, and solution of the early developmental problems; and to provide an update on progress made in development of the technology.

  8. DRUMS: a human disease related unique gene mutation search engine.

    Science.gov (United States)

    Li, Zuofeng; Liu, Xingnan; Wen, Jingran; Xu, Ye; Zhao, Xin; Li, Xuan; Liu, Lei; Zhang, Xiaoyan

    2011-10-01

    With the completion of the human genome project and the development of new methods for gene variant detection, the integration of mutation data and its phenotypic consequences has become more important than ever. Among all available resources, locus-specific databases (LSDBs) curate one or more specific genes' mutation data along with high-quality phenotypes. Although some genotype-phenotype data from LSDB have been integrated into central databases little effort has been made to integrate all these data by a search engine approach. In this work, we have developed disease related unique gene mutation search engine (DRUMS), a search engine for human disease related unique gene mutation as a convenient tool for biologists or physicians to retrieve gene variant and related phenotype information. Gene variant and phenotype information were stored in a gene-centred relational database. Moreover, the relationships between mutations and diseases were indexed by the uniform resource identifier from LSDB, or another central database. By querying DRUMS, users can access the most popular mutation databases under one interface. DRUMS could be treated as a domain specific search engine. By using web crawling, indexing, and searching technologies, it provides a competitively efficient interface for searching and retrieving mutation data and their relationships to diseases. The present system is freely accessible at http://www.scbit.org/glif/new/drums/index.html. © 2011 Wiley-Liss, Inc.

  9. Unique life sciences research facilities at NASA Ames Research Center

    Science.gov (United States)

    Mulenburg, G. M.; Vasques, M.; Caldwell, W. F.; Tucker, J.

    1994-01-01

    The Life Science Division at NASA's Ames Research Center has a suite of specialized facilities that enable scientists to study the effects of gravity on living systems. This paper describes some of these facilities and their use in research. Seven centrifuges, each with its own unique abilities, allow testing of a variety of parameters on test subjects ranging from single cells through hardware to humans. The Vestibular Research Facility allows the study of both centrifugation and linear acceleration on animals and humans. The Biocomputation Center uses computers for 3D reconstruction of physiological systems, and interactive research tools for virtual reality modeling. Psycophysiological, cardiovascular, exercise physiology, and biomechanical studies are conducted in the 12 bed Human Research Facility and samples are analyzed in the certified Central Clinical Laboratory and other laboratories at Ames. Human bedrest, water immersion and lower body negative pressure equipment are also available to study physiological changes associated with weightlessness. These and other weightlessness models are used in specialized laboratories for the study of basic physiological mechanisms, metabolism and cell biology. Visual-motor performance, perception, and adaptation are studied using ground-based models as well as short term weightlessness experiments (parabolic flights). The unique combination of Life Science research facilities, laboratories, and equipment at Ames Research Center are described in detail in relation to their research contributions.

  10. TIME SERIES ANALYSIS USING A UNIQUE MODEL OF TRANSFORMATION

    Directory of Open Access Journals (Sweden)

    Goran Klepac

    2007-12-01

    Full Text Available REFII1 model is an authorial mathematical model for time series data mining. The main purpose of that model is to automate time series analysis, through a unique transformation model of time series. An advantage of this approach of time series analysis is the linkage of different methods for time series analysis, linking traditional data mining tools in time series, and constructing new algorithms for analyzing time series. It is worth mentioning that REFII model is not a closed system, which means that we have a finite set of methods. At first, this is a model for transformation of values of time series, which prepares data used by different sets of methods based on the same model of transformation in a domain of problem space. REFII model gives a new approach in time series analysis based on a unique model of transformation, which is a base for all kind of time series analysis. The advantage of REFII model is its possible application in many different areas such as finance, medicine, voice recognition, face recognition and text mining.

  11. Arm coordination in octopus crawling involves unique motor control strategies.

    Science.gov (United States)

    Levy, Guy; Flash, Tamar; Hochner, Binyamin

    2015-05-04

    To cope with the exceptional computational complexity that is involved in the control of its hyper-redundant arms [1], the octopus has adopted unique motor control strategies in which the central brain activates rather autonomous motor programs in the elaborated peripheral nervous system of the arms [2, 3]. How octopuses coordinate their eight long and flexible arms in locomotion is still unknown. Here, we present the first detailed kinematic analysis of octopus arm coordination in crawling. The results are surprising in several respects: (1) despite its bilaterally symmetrical body, the octopus can crawl in any direction relative to its body orientation; (2) body and crawling orientation are monotonically and independently controlled; and (3) contrasting known animal locomotion, octopus crawling lacks any apparent rhythmical patterns in limb coordination, suggesting a unique non-rhythmical output of the octopus central controller. We show that this uncommon maneuverability is derived from the radial symmetry of the arms around the body and the simple pushing-by-elongation mechanism by which the arms create the crawling thrust. These two together enable a mechanism whereby the central controller chooses in a moment-to-moment fashion which arms to recruit for pushing the body in an instantaneous direction. Our findings suggest that the soft molluscan body has affected in an embodied way [4, 5] the emergence of the adaptive motor behavior of the octopus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Common processes at unique volcanoes – a volcanological conundrum

    Directory of Open Access Journals (Sweden)

    Katharine eCashman

    2014-11-01

    Full Text Available An emerging challenge in modern volcanology is the apparent contradiction between the perception that every volcano is unique, and classification systems based on commonalities among volcano morphology and eruptive style. On the one hand, detailed studies of individual volcanoes show that a single volcano often exhibits similar patterns of behaviour over multiple eruptive episodes; this observation has led to the idea that each volcano has its own distinctive pattern of behaviour (or personality. In contrast, volcano classification schemes define eruption styles referenced to type volcanoes (e.g. Plinian, Strombolian, Vulcanian; this approach implicitly assumes that common processes underpin volcanic activity and can be used to predict the nature, extent and ensuing hazards of individual volcanoes. Actual volcanic eruptions, however, often include multiple styles, and type volcanoes may experience atypical eruptions (e.g., violent explosive eruptions of Kilauea, Hawaii1. The volcanological community is thus left with a fundamental conundrum that pits the uniqueness of individual volcanic systems against generalization of common processes. Addressing this challenge represents a major challenge to volcano research.

  13. Unique phytochrome responses of the holoparasitic plant Orobanche minor.

    Science.gov (United States)

    Takagi, Kazuteru; Okazawa, Atsushi; Wada, Yu; Mongkolchaiyaphruek, Anchaya; Fukusaki, Eiichiro; Yoneyama, Koichi; Takeuchi, Yasutomo; Kobayashi, Akio

    2009-06-01

    Holoparasitic plants such as Orobanche spp. have lost their photosynthetic ability, so photoresponses to optimize photosynthesis are not necessary in these plants. Photoresponses are also involved in the regulation of plant development but the photoresponses of holoparasites have not been characterized in detail. In this study, the phytochrome (phy)-related photoresponse of Orobanche minor was investigated. Its photoreceptor, phytochrome A (OmphyA), was also characterized. Light effects on germination, shoot elongation, anthocyanin biosynthesis, and OmphyA expression and subcellular localization were analyzed. Red light (R):far-red light (FR) reversible inhibition of O. minor seed germination demonstrated that phy-mediated responses are retained in this holoparasite. Shoot elongation was inhibited by FR but not by R. This pattern is unique among known patterns of plant photoresponses. Additionally, molecular analysis showed that OmphyA is able to respond to the light signals. Interestingly, the unique pattern of photoresponses in O. minor seems to have been modified for adaptation to its parasitic life cycle. We hypothesize that this alteration has resulted from the loss or alteration of some phy-signaling components. Elucidation of altered components in phy signaling in this parasite will provide useful information not only about its physiological characteristics but also about general plant photoreception systems.

  14. [Reactance proneness, collectivism, uniqueness, and resistance to persuasion].

    Science.gov (United States)

    Imajo, Shuzo

    2002-10-01

    This study examined the reliability and validity of Japanese psychological reactance scales. A total of 167 undergraduates completed a questionnaire of Therapeutic Reactance Scale (TRS), the Hong Reactance Scale (HRS), the Uniqueness Scale, and the Collectivism Scale. They also received messages involving three persuasion situations that were either high or low in terms of threat, and were asked to describe their reactions to them. The author categorized the reactions into three: acceptance, indirect resistance, and direct resistance. Reliabilities of the reactance scales were satisfactory. Their scores positively correlated with uniqueness scores, and negatively with collectivism scores. Those high on reactance proneness were less persuaded in two of the three situations. But in the third, an HRS by threat interaction was observed, indicating that only those who were high on reactance proneness under the high-threat condition showed resistance to persuasion. These results suggest that the Japanese versions of reactance scale were reliable and valid. However, the assertiveness aspect of TRS may not be appropriate for the definition of reactance. The influence of culture on psychological reactance was also discussed.

  15. Questions of uniqueness and resolution in reconstruction from projections

    CERN Document Server

    Katz, Myron Bernard

    1978-01-01

    Reconstruction from projections has revolutionized radiology and as now become one of the most important tools of medical diagnosi- he E. M. I. Scanner is one example. In this text, some fundamental heoretical and practical questions are resolved. Despite recent research activity in the area, the crucial subject ·f the uniqueness of the reconstruction and the effect of noise in the ata posed some unsettled fundamental questions. In particular, Kennan mith proved that if we describe an object by a C~ function, i. e. , nfinitely differentiable with compact support, then there are other bjects with the same shape, i. e. , support, which can differ almost rhitrarily and still have the same projections in finitely many direc­ ions. On the other hand, he proved that objects in finite dimensional unction spaces are uniquely determined by a single projection for almost 11 angles, i. e. , except on a set of measure zero. Along these lines, erman and Rowland in [41) showed that reconstructions obtained from he common...

  16. Field Measurement-Based System Identification and Dynamic Response Prediction of a Unique MIT Building.

    Science.gov (United States)

    Cha, Young-Jin; Trocha, Peter; Büyüköztürk, Oral

    2016-07-01

    Tall buildings are ubiquitous in major cities and house the homes and workplaces of many individuals. However, relatively few studies have been carried out to study the dynamic characteristics of tall buildings based on field measurements. In this paper, the dynamic behavior of the Green Building, a unique 21-story tall structure located on the campus of the Massachusetts Institute of Technology (MIT, Cambridge, MA, USA), was characterized and modeled as a simplified lumped-mass beam model (SLMM), using data from a network of accelerometers. The accelerometer network was used to record structural responses due to ambient vibrations, blast loading, and the October 16th 2012 earthquake near Hollis Center (ME, USA). Spectral and signal coherence analysis of the collected data was used to identify natural frequencies, modes, foundation rocking behavior, and structural asymmetries. A relation between foundation rocking and structural natural frequencies was also found. Natural frequencies and structural acceleration from the field measurements were compared with those predicted by the SLMM which was updated by inverse solving based on advanced multiobjective optimization methods using the measured structural responses and found to have good agreement.

  17. Field Measurement-Based System Identification and Dynamic Response Prediction of a Unique MIT Building

    Directory of Open Access Journals (Sweden)

    Young-Jin Cha

    2016-07-01

    Full Text Available Tall buildings are ubiquitous in major cities and house the homes and workplaces of many individuals. However, relatively few studies have been carried out to study the dynamic characteristics of tall buildings based on field measurements. In this paper, the dynamic behavior of the Green Building, a unique 21-story tall structure located on the campus of the Massachusetts Institute of Technology (MIT, Cambridge, MA, USA, was characterized and modeled as a simplified lumped-mass beam model (SLMM, using data from a network of accelerometers. The accelerometer network was used to record structural responses due to ambient vibrations, blast loading, and the October 16th 2012 earthquake near Hollis Center (ME, USA. Spectral and signal coherence analysis of the collected data was used to identify natural frequencies, modes, foundation rocking behavior, and structural asymmetries. A relation between foundation rocking and structural natural frequencies was also found. Natural frequencies and structural acceleration from the field measurements were compared with those predicted by the SLMM which was updated by inverse solving based on advanced multiobjective optimization methods using the measured structural responses and found to have good agreement.

  18. Field Measurement-Based System Identification and Dynamic Response Prediction of a Unique MIT Building

    Science.gov (United States)

    Cha, Young-Jin; Trocha, Peter; Büyüköztürk, Oral

    2016-01-01

    Tall buildings are ubiquitous in major cities and house the homes and workplaces of many individuals. However, relatively few studies have been carried out to study the dynamic characteristics of tall buildings based on field measurements. In this paper, the dynamic behavior of the Green Building, a unique 21-story tall structure located on the campus of the Massachusetts Institute of Technology (MIT, Cambridge, MA, USA), was characterized and modeled as a simplified lumped-mass beam model (SLMM), using data from a network of accelerometers. The accelerometer network was used to record structural responses due to ambient vibrations, blast loading, and the October 16th 2012 earthquake near Hollis Center (ME, USA). Spectral and signal coherence analysis of the collected data was used to identify natural frequencies, modes, foundation rocking behavior, and structural asymmetries. A relation between foundation rocking and structural natural frequencies was also found. Natural frequencies and structural acceleration from the field measurements were compared with those predicted by the SLMM which was updated by inverse solving based on advanced multiobjective optimization methods using the measured structural responses and found to have good agreement. PMID:27376303

  19. Interdependencies of Arctic land surface processes: A uniquely sensitive environment

    Science.gov (United States)

    Bowling, L. C.

    2007-12-01

    The circumpolar arctic drainage basin is composed of several distinct ecoregions including steppe grassland and cropland, boreal forest and tundra. Land surface hydrology throughout this diverse region shares several unique features such as dramatic seasonal runoff differences controlled by snowmelt and ice break-up; the storage of significant portions of annual precipitation as snow and in lakes and wetlands; and the effects of ephemeral and permanently frozen soils. These arctic land processes are delicately balanced with the climate and are therefore important indicators of change. The litany of recently-detected changes in the Arctic includes changes in snow precipitation, trends and seasonal shifts in river discharge, increases and decreases in the extent of surface water, and warming soil temperatures. Although not unique to the arctic, increasing anthropogenic pressures represent an additional element of change in the form of resource extraction, fire threat and reservoir construction. The interdependence of the physical, biological and social systems mean that changes in primary indicators have large implications for land cover, animal populations and the regional carbon balance, all of which have the potential to feed back and induce further change. In fact, the complex relationships between the hydrological processes that make the Artic unique also render observed historical change difficult to interpret and predict, leading to conflicting explanations. For example, a decrease in snow accumulation may provide less insulation to the underlying soil resulting in greater frost development and increased spring runoff. Similarly, melting permafrost and ground ice may lead to ground subsidence and increased surface saturation and methane production, while more complete thaw may enhance drainage and result in drier soil conditions. The threshold nature of phase change around the freezing point makes the system especially sensitive to change. In addition, spatial

  20. The Glory Program: Global Science from a Unique Spacecraft Integration

    Science.gov (United States)

    Bajpayee Jaya; Durham, Darcie; Ichkawich, Thomas

    2006-01-01

    The Glory program is an Earth and Solar science mission designed to broaden science community knowledge of the environment. The causes and effects of global warming have become a concern in recent years and Glory aims to contribute to the knowledge base of the science community. Glory is designed for two functions: one is solar viewing to monitor the total solar irradiance and the other is observing the Earth s atmosphere for aerosol composition. The former is done with an active cavity radiometer, while the latter is accomplished with an aerosol polarimeter sensor to discern atmospheric particles. The Glory program is managed by NASA Goddard Space Flight Center (GSFC) with Orbital Sciences in Dulles, VA as the prime contractor for the spacecraft bus, mission operations, and ground system. This paper will describe some of the more unique features of the Glory program including the integration and testing of the satellite and instruments as well as the science data processing. The spacecraft integration and test approach requires extensive analysis and additional planning to ensure existing components are successfully functioning with the new Glory components. The science mission data analysis requires development of mission unique processing systems and algorithms. Science data analysis and distribution will utilize our national assets at the Goddard Institute for Space Studies (GISS) and the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP). The Satellite was originally designed and built for the Vegetation Canopy Lidar (VCL) mission, which was terminated in the middle of integration and testing due to payload development issues. The bus was then placed in secure storage in 2001 and removed from an environmentally controlled container in late 2003 to be refurbished to meet the Glory program requirements. Functional testing of all the components was done as a system at the start of the program, very different from a traditional program

  1. Unique self-assembly properties of a bridge-shaped protein dimer with quantum dots

    International Nuclear Information System (INIS)

    Wang, Jianhao; Jiang, Pengju; Gao, Liqian; Yu, Yongsheng; Lu, Yao; Qiu, Lin; Wang, Cheli; Xia, Jiang

    2013-01-01

    How protein–protein interaction affects protein–nanoparticle self-assembly is the key to the understanding of biomolecular coating of nanoparticle in biological fluids. However, the relationship between protein shape and its interaction with nanoparticles is still under-exploited because of lack of a well-conceived binding system and a method to detect the subtle change in the protein–nanoparticle assemblies. Noticing this unresolved need, we cloned and expressed a His-tagged SpeA protein that adopts a bridge-shaped dimer structure, and utilized a high-resolution capillary electrophoresis method to monitor assembly formation between the protein and quantum dots (QDs, 5 nm in diameter). We observed that the bridge-shaped structure rendered a low SpeA:QD stoichiometry at saturation. Also, close monitoring of imidazole (Im) displacement of surface-bound protein revealed a unique two-step process. High-concentration Im could displace surface-bound SpeA protein and form a transient QD–protein intermediate, through a kinetically controlled displacement process. An affinity-driven equilibrium step then followed, resulting in re-assembling of the QD–protein complex in about 1 h. Through a temporarily formed intermediate, Im causes a rearrangement of His-tagged proteins on the surface. Thus, our work showcases that the synergistic interplay between QD–His-tag interaction and protein–protein interaction can result in unique properties of protein–nanoparticle assembly for the first time

  2. Separating Common from Unique Variance Within Emotional Distress: An Examination of Reliability and Relations to Worry.

    Science.gov (United States)

    Marshall, Andrew J; Evanovich, Emma K; David, Sarah Jo; Mumma, Gregory H

    2018-01-17

    High comorbidity rates among emotional disorders have led researchers to examine transdiagnostic factors that may contribute to shared psychopathology. Bifactor models provide a unique method for examining transdiagnostic variables by modelling the common and unique factors within measures. Previous findings suggest that the bifactor model of the Depression Anxiety and Stress Scale (DASS) may provide a method for examining transdiagnostic factors within emotional disorders. This study aimed to replicate the bifactor model of the DASS, a multidimensional measure of psychological distress, within a US adult sample and provide initial estimates of the reliability of the general and domain-specific factors. Furthermore, this study hypothesized that Worry, a theorized transdiagnostic variable, would show stronger relations to general emotional distress than domain-specific subscales. Confirmatory factor analysis was used to evaluate the bifactor model structure of the DASS in 456 US adult participants (279 females and 177 males, mean age 35.9 years) recruited online. The DASS bifactor model fitted well (CFI = 0.98; RMSEA = 0.05). The General Emotional Distress factor accounted for most of the reliable variance in item scores. Domain-specific subscales accounted for modest portions of reliable variance in items after accounting for the general scale. Finally, structural equation modelling indicated that Worry was strongly predicted by the General Emotional Distress factor. The DASS bifactor model is generalizable to a US community sample and General Emotional Distress, but not domain-specific factors, strongly predict the transdiagnostic variable Worry.

  3. Unique self-assembly properties of a bridge-shaped protein dimer with quantum dots

    Science.gov (United States)

    Wang, Jianhao; Jiang, Pengju; Gao, Liqian; Yu, Yongsheng; Lu, Yao; Qiu, Lin; Wang, Cheli; Xia, Jiang

    2013-09-01

    How protein-protein interaction affects protein-nanoparticle self-assembly is the key to the understanding of biomolecular coating of nanoparticle in biological fluids. However, the relationship between protein shape and its interaction with nanoparticles is still under-exploited because of lack of a well-conceived binding system and a method to detect the subtle change in the protein-nanoparticle assemblies. Noticing this unresolved need, we cloned and expressed a His-tagged SpeA protein that adopts a bridge-shaped dimer structure, and utilized a high-resolution capillary electrophoresis method to monitor assembly formation between the protein and quantum dots (QDs, 5 nm in diameter). We observed that the bridge-shaped structure rendered a low SpeA:QD stoichiometry at saturation. Also, close monitoring of imidazole (Im) displacement of surface-bound protein revealed a unique two-step process. High-concentration Im could displace surface-bound SpeA protein and form a transient QD-protein intermediate, through a kinetically controlled displacement process. An affinity-driven equilibrium step then followed, resulting in re-assembling of the QD-protein complex in about 1 h. Through a temporarily formed intermediate, Im causes a rearrangement of His-tagged proteins on the surface. Thus, our work showcases that the synergistic interplay between QD-His-tag interaction and protein-protein interaction can result in unique properties of protein-nanoparticle assembly for the first time.

  4. On the uniqueness of color patterns in raptor feathers

    Science.gov (United States)

    Ellis, D.H.

    2009-01-01

    For this study, I compared sequentially molted feathers for a few captive raptors from year to year and symmetrically matched feathers (left/right pairs) for many raptors to see if color patterns of sequential feather pairs were identical or if symmetrical pairs were mirror-image identical. Feather pairs were found to be identical only when without color pattern (e.g., the all-white rectrices of Bald Eagles [Haliaeetus leucocephalus]). Complex patterns were not closely matched, but some simple patterns were sometimes closely matched, although not identical. Previous claims that complex color patterns in feather pairs are fingerprint-identical (and therefore that molted feathers from wild raptors can be used to identify breeding adults from year to year with certainty) were found to be untrue: each feather is unique. Although it is unwise to be certain of bird of origin using normal feathers, abnormal feathers can often be so used. ?? 2009 The Raptor Research Foundation, Inc.

  5. Did Lizards Follow Unique Pathways in Sex Chromosome Evolution?

    Science.gov (United States)

    Gleeson, Dianne; Georges, Arthur

    2018-01-01

    Reptiles show remarkable diversity in modes of reproduction and sex determination, including high variation in the morphology of sex chromosomes, ranging from homomorphic to highly heteromorphic. Additionally, the co-existence of genotypic sex determination (GSD) and temperature-dependent sex determination (TSD) within and among sister clades makes this group an attractive model to study and understand the evolution of sex chromosomes. This is particularly so with Lizards (Order Squamata) which, among reptiles, show extraordinary morphological diversity. They also show no particular pattern of sex chromosome degeneration of the kind observed in mammals, birds and or even in snakes. We therefore speculate that sex determination sensu sex chromosome evolution is labile and rapid and largely follows independent trajectories within lizards. Here, we review the current knowledge on the evolution of sex chromosomes in lizards and discuss how sex chromosome evolution within that group differs from other amniote taxa, facilitating unique evolutionary pathways. PMID:29751579

  6. Measles Outbreak with Unique Virus Genotyping, Ontario, Canada, 2015.

    Science.gov (United States)

    Thomas, Shari; Hiebert, Joanne; Gubbay, Jonathan B; Gournis, Effie; Sharron, Jennifer; Severini, Alberto; Jiaravuthisan, Manisa; Shane, Amanda; Jaeger, Valerie; Crowcroft, Natasha S; Fediurek, Jill; Sander, Beate; Mazzulli, Tony; Schulz, Helene; Deeks, Shelley L

    2017-07-01

    The province of Ontario continues to experience measles virus transmissions despite the elimination of measles in Canada. We describe an unusual outbreak of measles in Ontario, Canada, in early 2015 that involved cases with a unique strain of virus and no known association among primary case-patients. A total of 18 cases of measles were reported from 4 public health units during the outbreak period (January 25-March 23, 2015); none of these cases occurred in persons who had recently traveled. Despite enhancements to case-patient interview methods and epidemiologic analyses, a source patient was not identified. However, the molecular epidemiologic analysis, which included extended sequencing, strongly suggested that all cases derived from a single importation of measles virus genotype D4. The use of timely genotype sequencing, rigorous epidemiologic investigation, and a better understanding of the gaps in surveillance are needed to maintain Ontario's measles elimination status.

  7. A unique $Z_4^R$ symmetry for the MSSM

    CERN Document Server

    Lee, Hyun Min; Ratz, Michael; Ross, Graham G; Schieren, Roland; Schmidt-Hoberg, Kai; Vaudrevange, Patrick K S

    2011-01-01

    We consider the possible anomaly free Abelian discrete symmetries of the MSSM that forbid the mu-term at perturbative order. Allowing for anomaly cancellation via the Green-Schwarz mechanism we identify discrete R-symmetries as the only possibility and prove that there is a unique Z_4^R symmetry that commutes with SO(10). We argue that non-perturbative effects will generate a mu-term of electroweak order thus solving the mu-problem. The non-perturbative effects break the Z_4^R symmetry leaving an exact Z_2 matter parity. As a result dimension four baryon- and lepton-number violating operators are absent while, at the non-perturbative level, dimension five baryon- and lepton-number violating operators get induced but are highly suppressed so that the nucleon decay rate is well within present bounds.

  8. The unique predisposition to criminal violations in frontotemporal dementia.

    Science.gov (United States)

    Mendez, Mario F

    2010-01-01

    Brain disorders can lead to criminal violations. Patients with frontotemporal dementia (FTD) are particularly prone to sociopathic behavior while retaining knowledge of their acts and of moral and conventional rules. This report describes four FTD patients who committed criminal violations in the presence of clear consciousness and sufficiently intact cognition. They understood the nature of their acts and the potential consequences, but did not feel sufficiently concerned to be deterred. FTD involves a unique pathologic combination affecting the ventromedial prefrontal cortex, with altered moral feelings, right anterior temporal loss of emotional empathy, and orbitofrontal changes with disinhibited, compulsive behavior. These case histories and the literature indicate that those with right temporal FTD retain the capacity to tell right from wrong but have the slow and insidious loss of the capacity for moral rationality. Patients with early FTD present a challenge to the criminal justice system to consider alterations in moral cognition before ascribing criminal responsibility.

  9. Electroplating targets for production of unique PET radionuclides

    International Nuclear Information System (INIS)

    Bui, V.; Sheh, Y.; Finn, R.

    1994-01-01

    The past decade has witnessed the applications of Positron Emission Tomography (PET) evolving from a purely research endeavour to a procedure which has specific clinical applications in the areas of cardiology, neurology and oncology. The growth of PET has been facilitated by developments in medical instrumentation and radiopharmaceutical chemistry efforts. Included in this latter effort has been the low energy accelerator production and processing of unique PET radionuclides appropriate for the radiolabeling of biomolecules i.e. monoclonal antibodies and pepetides. The development and application of electroplated targets of antimony and copper for the production of iodine-124 and gallium-66 respectively, utilizing the Memorial Sloan-Kettering Cancer Center cyclotron are examples of target design and development applicable to many medical accelerators

  10. 4th June: AIS and NICE/MAIL unique authentication

    CERN Multimedia

    AIS and NICE teams

    2007-01-01

    Over the past few years, the IT department has been in the process of streamlining CERN users' access to all central computing services. The long term goal is to converge on a unique computer account, which will increase computer security and simplify account maintenance. The next step of this process will occur on 4th June 2007, as of when authenticating on the AIS applications (EDH, HRT, CET, APT, ERT, CRA, Foundation, ...) and on NICE (Windows) and MAIL will be done using the same username and password. As a reminder, this account can also be used on EDMS, INDICO, CDS and SIMBA. So starting on 4th June 2007, authentication on the AIS applications must be done using your AIS username and your MAIL/NICE password. Thanks for your understanding, The AIS and NICE teams

  11. 4th June: AIS and NICE/MAIL unique authentication

    CERN Multimedia

    The AIS and NICE teams

    2007-01-01

    Over the past few years, the IT department has been in the process of streamlining CERN users' access to all central computing services. The long term goal is to converge on a unique computer account, which will increase computer security and simplify account maintenance. The next step of this process will occur on the 4th June 2007, as of when authenticating on the AIS applications (EDH, HRT, CET, APT, ERT, CRA, Foundation, ...) and on NICE (Windows) and MAIL will be done using the same username and password. As a reminder, this account can also be used on EDMS, INDICO, CDS and SIMBA. Thus starting on the 4th June 2007, authentication on the AIS applications must be done using your AIS username and your MAIL/NICE password. Thanks for your understanding, The AIS and NICE teams

  12. Comparative developmental psychology: how is human cognitive development unique?

    Science.gov (United States)

    Rosati, Alexandra G; Wobber, Victoria; Hughes, Kelly; Santos, Laurie R

    2014-04-29

    The fields of developmental and comparative psychology both seek to illuminate the roots of adult cognitive systems. Developmental studies target the emergence of adult cognitive systems over ontogenetic time, whereas comparative studies investigate the origins of human cognition in our evolutionary history. Despite the long tradition of research in both of these areas, little work has examined the intersection of the two: the study of cognitive development in a comparative perspective. In the current article, we review recent work using this comparative developmental approach to study non-human primate cognition. We argue that comparative data on the pace and pattern of cognitive development across species can address major theoretical questions in both psychology and biology. In particular, such integrative research will allow stronger biological inferences about the function of developmental change, and will be critical in addressing how humans come to acquire species-unique cognitive abilities.

  13. Did Lizards Follow Unique Pathways in Sex Chromosome Evolution?

    Directory of Open Access Journals (Sweden)

    Shayer Mahmood Ibney Alam

    2018-05-01

    Full Text Available Reptiles show remarkable diversity in modes of reproduction and sex determination, including high variation in the morphology of sex chromosomes, ranging from homomorphic to highly heteromorphic. Additionally, the co-existence of genotypic sex determination (GSD and temperature-dependent sex determination (TSD within and among sister clades makes this group an attractive model to study and understand the evolution of sex chromosomes. This is particularly so with Lizards (Order Squamata which, among reptiles, show extraordinary morphological diversity. They also show no particular pattern of sex chromosome degeneration of the kind observed in mammals, birds and or even in snakes. We therefore speculate that sex determination sensu sex chromosome evolution is labile and rapid and largely follows independent trajectories within lizards. Here, we review the current knowledge on the evolution of sex chromosomes in lizards and discuss how sex chromosome evolution within that group differs from other amniote taxa, facilitating unique evolutionary pathways.

  14. A Unique Case of Systemic Lupus Erythematosus Pelvic Vasculitis

    Directory of Open Access Journals (Sweden)

    Pamela Traisak

    2016-01-01

    Full Text Available The clinical presentation of Systemic Lupus Erythematosus (SLE is diverse and vasculitis can be a potential manifestation. Cutaneous lesions involving small vessels are the most frequent presentation. However, medium and large vessel vasculitis may present with life-threatening visceral manifestations. We present a unique case of pelvic vasculitis mimicking a pelvic mass as an initial presentation of SLE. There are case reports of systemic vasculitis involving the female genital tract with giant cell arteritis (GCA, polyarteritis nodosa (PAN, and granulomatous with polyangiitis and microscopic polyangiitis (GPA/MPA, among others, but only a few cases attributed to SLE. Awareness of this condition and a prompt diagnosis are warranted as this is a severe and potentially life-threatening condition.

  15. A unique funding opportunity for public health in Texas.

    Science.gov (United States)

    Schlenker, Thomas; Huber, Carol A

    2015-01-01

    In addition to the Affordable Care Act, states are more frequently turning to Medicaid waivers to achieve the "Triple Aim" goals of improving the experience of care, improving population health, and reducing per capita costs. These demonstration waivers provide opportunities to test innovative ways to finance and deliver care. Texas is currently implementing a waiver known as the Transformation and Quality Improvement Program. Its inclusion of public health agencies is a unique approach to a system typically limited to traditional providers. San Antonio Metropolitan Health District is one public health agency taking advantage of this new funding opportunity to implement 6 new or expanded programs targeting health issues of highest priority in this south Texas region. This article discusses the use of Medicaid waivers and the advantages and challenges of public health agency participation.

  16. Ethics in Science: The Unique Consequences of Chemistry.

    Science.gov (United States)

    Kovac, Jeffrey

    2015-01-01

    This article discusses the ethical issues unique to the science and practice of chemistry. These issues arise from chemistry's position in the middle between the theoretical and the practical, a science concerned with molecules that are of the right size to directly affect human life. Many of the issues are raised by the central activity of chemistry--synthesis. Chemists make thousands of new substances each year. Many are beneficial, but others are threats. Since the development of the chemical industry in the nineteenth century, chemistry has contributed to the deterioration of the environment but has also helped to reduce pollution. Finally, we discuss the role of codes of ethics and whether the current codes of conduct for chemists are adequate for the challenges of today's world.

  17. Losing memories overnight: a unique form of human amnesia.

    Science.gov (United States)

    Smith, Christine N; Frascino, Jennifer C; Kripke, Donald L; McHugh, Paul R; Treisman, Glenn J; Squire, Larry R

    2010-08-01

    Since an automobile accident in 2005, patient FL has reported difficulty retaining information from one day to the next. During the course of any given day, she describes her memory as normal. However, memory for each day disappears during a night of sleep. She reports good memory for events that occurred before the accident. Although this pattern of memory impairment is, to our knowledge, unique to the medical literature, it was depicted in the fictional film "50 First Dates". On formal testing, FL performed moderately well when trying to remember material that she had learned during the same day, but she exhibited no memory at all for material that she knew had been presented on a previous day. For some tests, unbeknownst to FL, material learned on the previous day was intermixed with material learned on the same day as the test. On these occasions, FL's memory was good. Thus, she was able to remember events from earlier days when memory was tested covertly. FL performed differently in a number of ways from individuals who were instructed to consciously feign her pattern of memory impairment. It was also the impression of those who worked with FL that she believed she had the memory impairment that she described and that she was not intentionally feigning amnesia. On the basis of her neuropsychological findings, together with a normal neurological exam, normal MRI findings, and psychiatric evaluation, we suggest that FL exhibits a unique form of functional amnesia and that its characterization may have been influenced by knowledge of how amnesia was depicted in a popular film. She subsequently improved (and began retaining day-to-day memory) at Johns Hopkins University where she was in a supportive in-patient environment and was shown how to take control of her condition by interrupting her sleep at 4-h intervals. Published by Elsevier Ltd.

  18. Skipper genome sheds light on unique phenotypic traits and phylogeny.

    Science.gov (United States)

    Cong, Qian; Borek, Dominika; Otwinowski, Zbyszek; Grishin, Nick V

    2015-08-27

    Butterflies and moths are emerging as model organisms in genetics and evolutionary studies. The family Hesperiidae (skippers) was traditionally viewed as a sister to other butterflies based on its moth-like morphology and darting flight habits with fast wing beats. However, DNA studies suggest that the family Papilionidae (swallowtails) may be the sister to other butterflies including skippers. The moth-like features and the controversial position of skippers in Lepidoptera phylogeny make them valuable targets for comparative genomics. We obtained the 310 Mb draft genome of the Clouded Skipper (Lerema accius) from a wild-caught specimen using a cost-effective strategy that overcomes the high (1.6 %) heterozygosity problem. Comparative analysis of Lerema accius and the highly heterozygous genome of Papilio glaucus revealed differences in patterns of SNP distribution, but similarities in functions of genes that are enriched in non-synonymous SNPs. Comparison of Lepidoptera genomes revealed possible molecular bases for unique traits of skippers: a duplication of electron transport chain components could result in efficient energy supply for their rapid flight; a diversified family of predicted cellulases might allow them to feed on cellulose-enriched grasses; an expansion of pheromone-binding proteins and enzymes for pheromone synthesis implies a more efficient mate-recognition system, which compensates for the lack of clear visual cues due to the similarities in wing colors and patterns of many species of skippers. Phylogenetic analysis of several Lepidoptera genomes suggested that the position of Hesperiidae remains uncertain as the tree topology varied depending on the evolutionary model. Completion of the first genome from the family Hesperiidae allowed comparative analyses with other Lepidoptera that revealed potential genetic bases for the unique phenotypic traits of skippers. This work lays the foundation for future experimental studies of skippers and

  19. Using photoelectron diffraction to determine complex molecular adsorption structures

    International Nuclear Information System (INIS)

    Woodruff, D P

    2010-01-01

    Backscattering photoelectron diffraction, particularly in the energy-scan mode, is now an established technique for determining in a quantitative fashion the local structure of adsorbates on surfaces, and has been used successfully for ∼100 adsorbate phases. The elemental and chemical-state specificity afforded by the characteristic core level photoelectron binding energies means that it has particular advantages for molecular adsorbates, as the local geometry of inequivalent atoms in the molecule can be determined in a largely independent fashion. On the other hand, polyatomic molecules present a general problem for all methods of surface structure determination in that a mismatch of intramolecular distances with interatomic distances on the substrate surface means that the atoms in the adsorbed molecule are generally in low-symmetry sites. The quantities measured experimentally then represent an incoherent sum of the properties of each structural domain that is inequivalent with respect to the substrate point group symmetry. This typically leads to greater ambiguity or precision in the structural solutions. The basic principles of the method are described and illustrated with a simple example involving molecule/substrate bonding through only one constituent atom (TiO 2 -(110)/H 2 O). This example demonstrates the importance of obtaining quantitative local structural information. Further examples illustrate both the successes and the problems of this approach when applied to somewhat more complex molecular adsorbates.

  20. Cytotoxic protein from the mushroom Coprinus comatus possesses a unique mode for glycan binding and specificity

    Science.gov (United States)

    Zhang, Peilan; Yang, Guang; Xia, Changqing; Polston, Jane E.; Li, Gengnan; Li, Shiwu; Lin, Zhao; Yang, Li-jun; Bruner, Steven D.

    2017-01-01

    Glycans possess significant chemical diversity; glycan binding proteins (GBPs) recognize specific glycans to translate their structures to functions in various physiological and pathological processes. Therefore, the discovery and characterization of novel GBPs and characterization of glycan–GBP interactions are significant to provide potential targets for therapeutic intervention of many diseases. Here, we report the biochemical, functional, and structural characterization of a 130-amino-acid protein, Y3, from the mushroom Coprinus comatus. Biochemical studies of recombinant Y3 from a yeast expression system demonstrated the protein is a unique GBP. Additionally, we show that Y3 exhibits selective and potent cytotoxicity toward human T-cell leukemia Jurkat cells compared with a panel of cancer cell lines via inducing caspase-dependent apoptosis. Screening of a glycan array demonstrated GalNAcβ1–4(Fucα1–3)GlcNAc (LDNF) as a specific Y3-binding ligand. To provide a structural basis for function, the crystal structure was solved to a resolution of 1.2 Å, revealing a single-domain αβα-sandwich motif. Two monomers were dimerized to form a large 10-stranded, antiparallel β-sheet flanked by α-helices on each side, representing a unique oligomerization mode among GBPs. A large glycan binding pocket extends into the dimeric interface, and docking of LDNF identified key residues for glycan interactions. Disruption of residues predicted to be involved in LDNF/Y3 interactions resulted in the significant loss of binding to Jurkat T-cells and severely impaired their cytotoxicity. Collectively, these results demonstrate Y3 to be a GBP with selective cytotoxicity toward human T-cell leukemia cells and indicate its potential use in cancer diagnosis and treatment. PMID:28784797

  1. Cytotoxic protein from the mushroom Coprinus comatus possesses a unique mode for glycan binding and specificity.

    Science.gov (United States)

    Zhang, Peilan; Li, Kunhua; Yang, Guang; Xia, Changqing; Polston, Jane E; Li, Gengnan; Li, Shiwu; Lin, Zhao; Yang, Li-Jun; Bruner, Steven D; Ding, Yousong

    2017-08-22

    Glycans possess significant chemical diversity; glycan binding proteins (GBPs) recognize specific glycans to translate their structures to functions in various physiological and pathological processes. Therefore, the discovery and characterization of novel GBPs and characterization of glycan-GBP interactions are significant to provide potential targets for therapeutic intervention of many diseases. Here, we report the biochemical, functional, and structural characterization of a 130-amino-acid protein, Y3, from the mushroom Coprinus comatus Biochemical studies of recombinant Y3 from a yeast expression system demonstrated the protein is a unique GBP. Additionally, we show that Y3 exhibits selective and potent cytotoxicity toward human T-cell leukemia Jurkat cells compared with a panel of cancer cell lines via inducing caspase-dependent apoptosis. Screening of a glycan array demonstrated GalNAcβ1-4(Fucα1-3)GlcNAc (LDNF) as a specific Y3-binding ligand. To provide a structural basis for function, the crystal structure was solved to a resolution of 1.2 Å, revealing a single-domain αβα-sandwich motif. Two monomers were dimerized to form a large 10-stranded, antiparallel β-sheet flanked by α-helices on each side, representing a unique oligomerization mode among GBPs. A large glycan binding pocket extends into the dimeric interface, and docking of LDNF identified key residues for glycan interactions. Disruption of residues predicted to be involved in LDNF/Y3 interactions resulted in the significant loss of binding to Jurkat T-cells and severely impaired their cytotoxicity. Collectively, these results demonstrate Y3 to be a GBP with selective cytotoxicity toward human T-cell leukemia cells and indicate its potential use in cancer diagnosis and treatment.

  2. AFRICOM: A Unique Opportunity to Reshape Civil/Military Relationships

    National Research Council Canada - National Science Library

    Gibbs, Richard W

    2007-01-01

    .... Department of State. Unfortunately, in limiting the senior civilian leadership to deputy status, the United States is not going far enough in its efforts to reorganize its combatant command leadership structure to deal...

  3. The cost of uniqueness in groundwater model calibration

    Science.gov (United States)

    Moore, Catherine; Doherty, John

    2006-04-01

    Calibration of a groundwater model requires that hydraulic properties be estimated throughout a model domain. This generally constitutes an underdetermined inverse problem, for which a solution can only be found when some kind of regularization device is included in the inversion process. Inclusion of regularization in the calibration process can be implicit, for example through the use of zones of constant parameter value, or explicit, for example through solution of a constrained minimization problem in which parameters are made to respect preferred values, or preferred relationships, to the degree necessary for a unique solution to be obtained. The "cost of uniqueness" is this: no matter which regularization methodology is employed, the inevitable consequence of its use is a loss of detail in the calibrated field. This, in turn, can lead to erroneous predictions made by a model that is ostensibly "well calibrated". Information made available as a by-product of the regularized inversion process allows the reasons for this loss of detail to be better understood. In particular, it is easily demonstrated that the estimated value for an hydraulic property at any point within a model domain is, in fact, a weighted average of the true hydraulic property over a much larger area. This averaging process causes loss of resolution in the estimated field. Where hydraulic conductivity is the hydraulic property being estimated, high averaging weights exist in areas that are strategically disposed with respect to measurement wells, while other areas may contribute very little to the estimated hydraulic conductivity at any point within the model domain, this possibly making the detection of hydraulic conductivity anomalies in these latter areas almost impossible. A study of the post-calibration parameter field covariance matrix allows further insights into the loss of system detail incurred through the calibration process to be gained. A comparison of pre- and post

  4. Structural and electronic properties of La C[sub 82

    Energy Technology Data Exchange (ETDEWEB)

    Laasonen, K.; Andreoni, W.; Parrinello, M. (Zurich Research Lab., Rueschlikon (Switzerland))

    1992-12-18

    The structural and electronic properties of the La C[sub 82] fullerene have been investigated by means of the Car-Parrinello method, which is based on the local density approximation of the density functional theory. The topological arrangement of the C[sub 82] cage was assumed to be a C[sub 3v] symmetry isomer. Three configurations were considered, one with the lanthanum atom at the center of the cluster, one with it along the threefold axis, and one with it at a low-symmetry, highly coordinated site. The structure was fully relaxed and it was found that the last of these configurations is energetically preferred. In this position, the lanthanum atom is nearly in a La[sup 3+] state and the unpaired electron is somewhat delocalized on the cage, in agreement with available experimental data. This arrangement suggests that the chemical shifts of the 5s and 5p lanthanum states can be used as a structural probe and as a way of further validating this picture. It is argued that this conclusion is not affected by the assumed fullerene structure.

  5. Crystal structure optimisation using an auxiliary equation of state

    Science.gov (United States)

    Jackson, Adam J.; Skelton, Jonathan M.; Hendon, Christopher H.; Butler, Keith T.; Walsh, Aron

    2015-11-01

    Standard procedures for local crystal-structure optimisation involve numerous energy and force calculations. It is common to calculate an energy-volume curve, fitting an equation of state around the equilibrium cell volume. This is a computationally intensive process, in particular, for low-symmetry crystal structures where each isochoric optimisation involves energy minimisation over many degrees of freedom. Such procedures can be prohibitive for non-local exchange-correlation functionals or other "beyond" density functional theory electronic structure techniques, particularly where analytical gradients are not available. We present a simple approach for efficient optimisation of crystal structures based on a known equation of state. The equilibrium volume can be predicted from one single-point calculation and refined with successive calculations if required. The approach is validated for PbS, PbTe, ZnS, and ZnTe using nine density functionals and applied to the quaternary semiconductor Cu2ZnSnS4 and the magnetic metal-organic framework HKUST-1.

  6. Crystal structure optimisation using an auxiliary equation of state

    International Nuclear Information System (INIS)

    Jackson, Adam J.; Skelton, Jonathan M.; Hendon, Christopher H.; Butler, Keith T.; 3 Institute and Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of))" data-affiliation=" (Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Global E3 Institute and Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of))" >Walsh, Aron

    2015-01-01

    Standard procedures for local crystal-structure optimisation involve numerous energy and force calculations. It is common to calculate an energy–volume curve, fitting an equation of state around the equilibrium cell volume. This is a computationally intensive process, in particular, for low-symmetry crystal structures where each isochoric optimisation involves energy minimisation over many degrees of freedom. Such procedures can be prohibitive for non-local exchange-correlation functionals or other “beyond” density functional theory electronic structure techniques, particularly where analytical gradients are not available. We present a simple approach for efficient optimisation of crystal structures based on a known equation of state. The equilibrium volume can be predicted from one single-point calculation and refined with successive calculations if required. The approach is validated for PbS, PbTe, ZnS, and ZnTe using nine density functionals and applied to the quaternary semiconductor Cu 2 ZnSnS 4 and the magnetic metal-organic framework HKUST-1

  7. Crystal structure optimisation using an auxiliary equation of state

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Adam J.; Skelton, Jonathan M.; Hendon, Christopher H.; Butler, Keith T. [Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Walsh, Aron, E-mail: a.walsh@bath.ac.uk [Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Global E" 3 Institute and Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2015-11-14

    Standard procedures for local crystal-structure optimisation involve numerous energy and force calculations. It is common to calculate an energy–volume curve, fitting an equation of state around the equilibrium cell volume. This is a computationally intensive process, in particular, for low-symmetry crystal structures where each isochoric optimisation involves energy minimisation over many degrees of freedom. Such procedures can be prohibitive for non-local exchange-correlation functionals or other “beyond” density functional theory electronic structure techniques, particularly where analytical gradients are not available. We present a simple approach for efficient optimisation of crystal structures based on a known equation of state. The equilibrium volume can be predicted from one single-point calculation and refined with successive calculations if required. The approach is validated for PbS, PbTe, ZnS, and ZnTe using nine density functionals and applied to the quaternary semiconductor Cu{sub 2}ZnSnS{sub 4} and the magnetic metal-organic framework HKUST-1.

  8. Generating unique IDs from patient identification data using security models

    Directory of Open Access Journals (Sweden)

    Emad A Mohammed

    2016-01-01

    Full Text Available Background: The use of electronic health records (EHRs has continued to increase within healthcare systems in the developed and developing nations. EHRs allow for increased patient safety, grant patients easier access to their medical records, and offer a wealth of data to researchers. However, various bioethical, financial, logistical, and information security considerations must be addressed while transitioning to an EHR system. The need to encrypt private patient information for data sharing is one of the foremost challenges faced by health information technology. Method: We describe the usage of the message digest-5 (MD5 and secure hashing algorithm (SHA as methods for encrypting electronic medical data. In particular, we present an application of the MD5 and SHA-1 algorithms in encrypting a composite message from private patient information. Results: The results show that the composite message can be used to create a unique one-way encrypted ID per patient record that can be used for data sharing. Conclusion: The described software tool can be used to share patient EMRs between practitioners without revealing patients identifiable data.

  9. Uniqueness and numerical methods in inverse obstacle scattering

    International Nuclear Information System (INIS)

    Kress, Rainer

    2007-01-01

    The inverse problem we consider in this tutorial is to determine the shape of an obstacle from the knowledge of the far field pattern for scattering of time-harmonic plane waves. In the first part we will concentrate on the issue of uniqueness, i.e., we will investigate under what conditions an obstacle and its boundary condition can be identified from a knowledge of its far field pattern for incident plane waves. We will review some classical and some recent results and draw attention to open problems. In the second part we will survey on numerical methods for solving inverse obstacle scattering problems. Roughly speaking, these methods can be classified into three groups. Iterative methods interpret the inverse obstacle scattering problem as a nonlinear ill-posed operator equation and apply iterative schemes such as regularized Newton methods, Landweber iterations or conjugate gradient methods for its solution. Decomposition methods, in principle, separate the inverse scattering problem into an ill-posed linear problem to reconstruct the scattered wave from its far field and the subsequent determination of the boundary of the scatterer from the boundary condition. Finally, the third group consists of the more recently developed sampling methods. These are based on the numerical evaluation of criteria in terms of indicator functions that decide whether a point lies inside or outside the scatterer. The tutorial will give a survey by describing one or two representatives of each group including a discussion on the various advantages and disadvantages

  10. The odontoid synchondrotic slip: an injury unique to young children

    International Nuclear Information System (INIS)

    Connolly, B.; Emery, D.; Armstrong, D.

    1995-01-01

    We report seven children (three female, four male) diagnosed with traumatic synchrondrotic slip of the odontoid. The clinical records, plain films, and CT scans were evaluated retrospectively. The patients ranged in age between 3 and 5 years. Their injuries resulted from a motor vehicle accident in four cases and from a fall from a height in three. The injury was isolated in five; it was associated with a closed head injury in one and with facial and brachial plexus trauma in another. Radiographs showed anterior angulation with or without displacement in all seven cases. Axial CT with sagittal reformation and 3D reconstructions were performed in six cases. This confirmed the synchrondrotic slip and, in addition, identified a rotary component to the injury in three cases, with compromise of the canal in two. Other additional injuries were also noted. All cases were treated conservatively and the injuries healed. Only one child had a neurological deficit attributable to her head injury rather than to her cervical injury (MR of the cervical cord was normal). The presence of the synchondrosis between the dens and the body of C-2 makes this injury unique to children under 7 years of age; by the age of 7 the synchrondrosis has fused. (orig.)

  11. Tropical wetlands and REDD+: Three unique scientific challenges for policy

    Directory of Open Access Journals (Sweden)

    Daniel A Friess

    2013-07-01

    Full Text Available The carbon sequestration and storage value of terrestrial habitats is now increasingly appreciated, and is the basis for Payment for Ecosystem Service (PES policies such as REDD+. Tropical wetlands may be suitable for inclusion in such schemes because of the disproportionately large volume of carbon they are able to store. However, tropical wetlands offer a number of unique challenges for carbon management and policy compared to terrestrial forest systems: 1 Tropical wetlands are dynamic and subject to a wide range of physical and ecological processes that affect their long-term carbon storage potential – thus, such systems can quickly become a carbon source instead of a sink; 2 Carbon dynamics in tropical wetlands often operate over longer time-scales than are currently covered by REDD+ payments; and 3 Much of the carbon in a tropical wetland is stored in the soil, so monitoring, reporting and verification (MRV needs to adequately encapsulate the entire ecosystem and not just the vegetative component. This paper discusses these physical and biological concepts, and highlights key legal, management and policy questions that must be considered when constructing a policy framework to conserve these crucial ecosystems.

  12. Plant Tolerance: A Unique Approach to Control Hemipteran Pests.

    Science.gov (United States)

    Koch, Kyle G; Chapman, Kaitlin; Louis, Joe; Heng-Moss, Tiffany; Sarath, Gautam

    2016-01-01

    Plant tolerance to insect pests has been indicated to be a unique category of resistance, however, very little information is available on the mechanism of tolerance against insect pests. Tolerance is distinctive in terms of the plant's ability to withstand or recover from herbivore injury through growth and compensatory physiological processes. Because plant tolerance involves plant compensatory characteristics, the plant is able to harbor large numbers of herbivores without interfering with the insect pest's physiology or behavior. Some studies have observed that tolerant plants can compensate photosynthetically by avoiding feedback inhibition and impaired electron flow through photosystem II that occurs as a result of insect feeding. Similarly, the up-regulation of peroxidases and other oxidative enzymes during insect feeding, in conjunction with elevated levels of phytohormones can play an important role in providing plant tolerance to insect pests. Hemipteran insects comprise some of the most economically important plant pests (e.g., aphids, whiteflies), due to their ability to achieve high population growth and their potential to transmit plant viruses. In this review, results from studies on plant tolerance to hemipterans are summarized, and potential models to understand tolerance are presented.

  13. Unique Education and Workforce Development for NASA Engineers

    Science.gov (United States)

    Forsgren, Roger C.; Miller, Lauren L.

    2010-01-01

    NASA engineers are some of the world's best-educated graduates, responsible for technically complex, highly significant scientific programs. Even though these professionals are highly proficient in traditional analytical competencies, there is a unique opportunity to offer continuing education that further enhances their overall scientific minds. With a goal of maintaining the Agency's passionate, "best in class" engineering workforce, the NASA Academy of Program/Project & Engineering Leadership (APPEL) provides educational resources encouraging foundational learning, professional development, and knowledge sharing. NASA APPEL is currently partnering with the scientific community's most respected subject matter experts to expand its engineering curriculum beyond the analytics and specialized subsystems in the areas of: understanding NASA's overall vision and its fundamental basis, and the Agency initiatives supporting them; sharing NASA's vast reservoir of engineering experience, wisdom, and lessons learned; and innovatively designing hardware for manufacturability, assembly, and servicing. It takes collaboration and innovation to educate an organization that possesses such a rich and important historyand a future that is of great global interest. NASA APPEL strives to intellectually nurture the Agency's technical professionals, build its capacity for future performance, and exemplify its core valuesalJ to better enable NASA to meet its strategic visionand beyond.

  14. Hawadith Street Initiative: A unique Sudanese childhood charity experience.

    Science.gov (United States)

    Ahmed, Awad Mohamed; A-Rahman, Nada Hassan Ahmed

    2015-01-01

    Due to escalating conflicts and resultant economic constraints, different social services in low income and low-middle income countries have witnessed a decline in its standards, and increase in the costs. This situation has led to emergence of large numbers of patients and their families who cannot afford the costs of health services provided by public hospitals. On this background, and the old heritage of the Sudanese to help the needy, the Hawadith Street Initiative (HSI) was established. Named after the street on which it was founded - which translates indirectly to "Accidents Lane", HSI was established in 2012 by a group of youths, most of them in their twenties of age, and recently graduated. The main activity of the initiative is helping the needy hospital patients, especially with regards to their treatment costs, in Khartoum and other cities in Sudan. Starting with recreational programs for cancer patients, and public campaigns for donation of blood, the initiative's youths changed their activities. Using the social media, Facebook, they adopted the strategy of communication with potential donors, after sending posts containing brief anonymous presentations and call of help for needy cases. Currently HSI includes more than 2000 volunteers in Khartoum and 17 other cities. The most important achievement of HSI is the establishment of an intensive care unit at a children hospital in Omdurman city costing 435,880 US dollars. HSI demonstrates the possibility of delivering great services with minimum resources, and constitutes a unique organization, worldwide, in a new wave of Internet-based initiatives.

  15. A unique dual activity amino acid hydroxylase in Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Gaskell

    Full Text Available The genome of the protozoan parasite Toxoplasma gondii was found to contain two genes encoding tyrosine hydroxylase; that produces L-DOPA. The encoded enzymes metabolize phenylalanine as well as tyrosine with substrate preference for tyrosine. Thus the enzymes catabolize phenylalanine to tyrosine and tyrosine to L-DOPA. The catalytic domain descriptive of this class of enzymes is conserved with the parasite enzyme and exhibits similar kinetic properties to metazoan tyrosine hydroxylases, but contains a unique N-terminal extension with a signal sequence motif. One of the genes, TgAaaH1, is constitutively expressed while the other gene, TgAaaH2, is induced during formation of the bradyzoites of the cyst stages of the life cycle. This is the first description of an aromatic amino acid hydroxylase in an apicomplexan parasite. Extensive searching of apicomplexan genome sequences revealed an ortholog in Neospora caninum but not in Eimeria, Cryptosporidium, Theileria, or Plasmodium. Possible role(s of these bi-functional enzymes during host infection are discussed.

  16. Preference for oddity: uniqueness heuristic or hierarchical choice process?

    Science.gov (United States)

    Waite, Thomas A

    2008-10-01

    Traditional economic theories assume decision makers in multialternative choice tasks "assign" a value to each option and then express rational preferences. Here, I report an apparent violation of such rationality in gray jays (Perisoreus canadensis). I tested the jays' preference in a quaternary choice task where three options were the same color and the fourth option was a different color. All options offered an identical food reward and so the strictly rational expectation was that subjects would choose the odd-colored option in 25% of choices. In clear disagreement, every subject chose the odd option more frequently than expected. I speculate as to how this surprising preference for oddity might have been ecologically rational: by using a unique-choice heuristic, the jays might have been able to bypass a deliberative phase of the decision process and devote more attention to scanning for predators. Alternatively, it is conceivable that the jays did not prefer oddity per se. Instead, they might have used a hierarchical process, assigning options to color categories and then choosing between categories. If so, their behavior matches expectation after all (on average, subjects chose the odd option 50% of the time). It should be straightforward to test these competing hypotheses. The current results can be viewed as a new example of how simple mechanisms sometimes produce economically puzzling yet ecologically rational decision making.

  17. Peripheral formalin injection induces unique spinal cord microglial phenotypic changes

    Science.gov (United States)

    Fu, Kai-Yuan; Tan, Yong-Hui; Sung, Backil; Mao, Jianren

    2014-01-01

    Microglia are resident immune cells of brain and activated by peripheral tissue injury. In the present study, we investigated the possible induction of several microglial surface immunomolecules in the spinal cord, including leukocyte common antigen (LCA/CD45), MHC class I antigen, MHC class II antigen, Fc receptor, and CD11c following formalin injection into the rat’s hind paw. CD45 and MHC class I were upregulated in the activated microglia, which was evident on day 3 with the peak expression on day 7 following peripheral formalin injection. There was a very low basal expression of MHC class II, CD11c, and the Fc receptor, which did not change after the formalin injection. These results, for the first time, indicate that peripheral formalin injection can induce phenotypic changes of microglia with distinct upregulation of CD45 and MHC class I antigen. The data suggest that phenotypic changes of the activated microglia may be a unique pattern of central changes following peripheral tissue injury. PMID:19015000

  18. Generating unique IDs from patient identification data using security models.

    Science.gov (United States)

    Mohammed, Emad A; Slack, Jonathan C; Naugler, Christopher T

    2016-01-01

    The use of electronic health records (EHRs) has continued to increase within healthcare systems in the developed and developing nations. EHRs allow for increased patient safety, grant patients easier access to their medical records, and offer a wealth of data to researchers. However, various bioethical, financial, logistical, and information security considerations must be addressed while transitioning to an EHR system. The need to encrypt private patient information for data sharing is one of the foremost challenges faced by health information technology. We describe the usage of the message digest-5 (MD5) and secure hashing algorithm (SHA) as methods for encrypting electronic medical data. In particular, we present an application of the MD5 and SHA-1 algorithms in encrypting a composite message from private patient information. The results show that the composite message can be used to create a unique one-way encrypted ID per patient record that can be used for data sharing. The described software tool can be used to share patient EMRs between practitioners without revealing patients identifiable data.

  19. Atlantic Coast Unique Regional Atmospheric Tracer Experiment (ACURATE)

    International Nuclear Information System (INIS)

    Schubert, J.F.; Heffter, J.L.; Mead, G.A.

    1983-05-01

    The Atlantic Coast Unique Regional Atmospheric Tracer Experiment (ACURATE) is a program designed to obtain data necessary to evaluate atmospheric transport and diffusion models used to calculate regional population doses caused by nuclear facility emissions to the atmosphere. This experiment will significantly improve the basis for evaluating the cost effectiveness of different methods of managing airborne nuclear wastes. During the period from March 1982 through September 1982, twice daily air samples have been collected at each of five sampling stations located on a radial from the SRP to Murray Hill, NJ (1000 km). Kr-85 emitted from the F and H area chemical separations facilities is being used as a tracer to determine the transport and diffusion of atmospheric releases from the SRP. The Kr-85 concentrations in the air samples will be compared with the calculated concentrations as predicted by the transport and diffusion models. The Kr-85 data and the meteorological data are being archived and will be made available to the modeling community

  20. Tibialis Posterior Tenosynovitis: A Unique Musculoskeletal Manifestation of Gout.

    Science.gov (United States)

    Shupper, Peter; Stitik, Todd P

    2018-02-01

    Extra-articular manifestations of gout can present in several ways, including tenosynovitis. We present a rare case of acute tibialis posterior gouty tenosynovitis. An 82-year-old man with a history of well-controlled gout presented with acute onset of left ankle pain, occurring without inciting event. The medial ankle was slightly erythematous with moderate dorsal-medial swelling and mild dorsal-lateral swelling, with severe tenderness to palpation over the medial retro-malleolar region. Range of motion and manual muscle testing were pain limited throughout. Ultrasound examination revealed a left posterior tibialis tendon sheath tenosynovitis with effusion and overlying soft tissue edema. Tendon sheath aspirate revealed sodium urate crystals and a white blood cell count of 6400/μL. Tendon sheath injection with a mixture of 1% lidocaine and dexamethasone 4 mg resulted in symptom resolution. Repeat ultrasound examination demonstrated no evidence of tibialis posterior tendon sheath effusion. This case is unique not only because acute gouty posterior tibialis tenosynovitis is very rare, particularly in a normouricemic individual, but also because the sonographic evidence of gouty infiltration into the posterior tibialis tendon and overlying subcutaneous tissue considerably aided in arriving at the correct diagnosis in a timely manner.

  1. Unique case of esophageal rupture after a fall from height

    Directory of Open Access Journals (Sweden)

    van Berge Henegouwen Mark I

    2009-12-01

    Full Text Available Abstract Background Traumatic ruptures of the esophagus are relatively rare. This condition is associated with high morbidity and mortality. Most traumatic ruptures occur after motor vehicle accidents. Case Presentation We describe a unique case of a 23 year old woman that presented at our trauma resuscitation room after a fall from 8 meters. During physical examination there were no clinical signs of life-threatening injuries. She did however have a massive amount of subcutaneous emphysema of the chest and neck and pneumomediastinum. Flexible laryngoscopy revealed a lesion in the upper esophagus just below the level of the upper esophageal sphincter. Despite preventive administration of intravenous antibiotics and nutrition via a nasogastric tube, the patient developed a cervical abscess, which drained spontaneously. Normal diet was gradually resumed after 2.5 weeks and the patient was discharged in a reasonable condition 3 weeks after the accident. Conclusions This case report presents a high cervical esophageal rupture without associated local injuries after a fall from height.

  2. On defining a unique phylogenetic tree with homoplastic characters.

    Science.gov (United States)

    Goloboff, Pablo A; Wilkinson, Mark

    2018-05-01

    This paper discusses the problem of whether creating a matrix with all the character state combinations that have a fixed number of steps (or extra steps) on a given tree T, produces the same tree T when analyzed with maximum parsimony or maximum likelihood. Exhaustive enumeration of cases up to 20 taxa for binary characters, and up to 12 taxa for 4-state characters, shows that the same tree is recovered (as unique most likely or most parsimonious tree) as long as the number of extra steps is within 1/4 of the number of taxa. This dependence, 1/4 of the number of taxa, is discussed with a general argumentation, in terms of the spread of the character changes on the tree used to select character state distributions. The present finding allows creating matrices which have as much homoplasy as possible for the most parsimonious or likely tree to be predictable, and examination of these matrices with hill-climbing search algorithms provides additional evidence on the (lack of a) necessary relationship between homoplasy and the ability of search methods to find optimal trees. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Unique topics and issues in rheumatology and clinical immunology.

    Science.gov (United States)

    Selmi, Carlo

    2014-08-01

    Clinicians are facing unexpected issues in everyday practice, and these may become counterintuitive or challenging. Illustrative examples are provided by the hypersensitivity to universally used immunosuppressants such as corticosteroids or antibiotics such as beta-lactam. Secondly, additional issues are represented by the discovery of new pathogenetic mechanisms involved in rheumatoid and psoriatic arthritis or other chronic inflammatory diseases, genomic susceptibility to enigmatic diseases such as giant cell arteritis, or the shared role of specific mediators such as semaphorins. Third, the therapeutic armamentarium has dramatically changed over the past decade following the introduction of biotechnological drugs, and new mechanisms are being proposed to reduce adverse events or increase the drug effectiveness, particularly on cardiovascular comorbidities. Finally, rare diseases continue to represent difficult cases, as for Cogan's syndrome, with limited literature available for clinical recommendations. For these reason, the present issue of Clinical Reviews in Allergy and Immunology is timely and dedicated to these and other unique topics in clinical immunology and allergy. The aim of this issue is thus to help clinicians involved in internal medicine as well as allergists and clinical immunologists while discussing new pathways that will prove important in the near future.

  4. Fingerprint: A Unique and Reliable Method for Identification

    Directory of Open Access Journals (Sweden)

    Palash Kumar Bose

    2017-01-01

    Full Text Available Fingerprints have been the gold standard for personal identification within the forensic community for more than one hundred years. It is still universal in spite of discovery of DNA fingerprint. The science of fingerprint identification has evolved over time from the early use of finger prints to mark business transactions in ancient Babylonia to their use today as core technology in biometric security devices and as scientific evidence in courts of law throughout the world. The science of fingerprints, dactylography or dermatoglyphics, had long been widely accepted, and well acclaimed and reputed as panacea for individualization, particularly in forensic investigations. Human fingerprints are detailed, unique, difficult to alter, and durable over the life of an individual, making them suitable as lifelong markers of human identity. Fingerprints can be readily used by police or other authorities to identify individuals who wish to conceal their identity, or to identify people who are incapacitated or deceased, as in the aftermath of a natural disaster

  5. Uniqueness of thermodynamic projector and kinetic basis of molecular individualism

    Science.gov (United States)

    Gorban, Alexander N.; Karlin, Iliya V.

    2004-05-01

    Three results are presented: First, we solve the problem of persistence of dissipation for reduction of kinetic models. Kinetic equations with thermodynamic Lyapunov functions are studied. Uniqueness of the thermodynamic projector is proven: There exists only one projector which transforms any vector field equipped with the given Lyapunov function into a vector field with the same Lyapunov function for a given anzatz manifold which is not tangent to the Lyapunov function levels. Second, we use the thermodynamic projector for developing the short memory approximation and coarse-graining for general nonlinear dynamic systems. We prove that in this approximation the entropy production increases. ( The theorem about entropy overproduction.) In example, we apply the thermodynamic projector to derive the equations of reduced kinetics for the Fokker-Planck equation. A new class of closures is developed, the kinetic multipeak polyhedra. Distributions of this type are expected in kinetic models with multidimensional instability as universally as the Gaussian distribution appears for stable systems. The number of possible relatively stable states of a nonequilibrium system grows as 2 m, and the number of macroscopic parameters is in order mn, where n is the dimension of configuration space, and m is the number of independent unstable directions in this space. The elaborated class of closures and equations pretends to describe the effects of “molecular individualism”. This is the third result.

  6. Mad scientist: the unique case of a published delusion.

    Science.gov (United States)

    Shelomi, Matan

    2013-06-01

    In 1951, entomologist Jay Traver published in the Proceedings of the Entomological Society of Washington her personal experiences with a mite infestation of her scalp that resisted all treatment and was undetectable to anyone other than herself. Traver is recognized as having suffered from Delusory Parasitosis: her paper shows her to be a textbook case of the condition. The Traver paper is unique in the scientific literature in that its conclusions may be based on data that was unconsciously fabricated by the author's mind. The paper may merit retraction on the grounds of error or even scientific misconduct "by reason of insanity," but such a retraction raises the issue of discrimination against the mentally ill. This article asks what responsibilities journals have when faced with delusions disguised as science, what right editors have to question the sanity of an author, and what should be done about the Traver paper itself. By placing higher emphasis on article content than author identity, scientific integrity is maintained and a balance is struck between avoiding discrimination against the mentally ill and not preventing patients from seeking needed treatment.

  7. A UNIQUE CASE OF PHEOCHROMOCYTOMA PRESENTING WITH HYPERTENSIVE RETINOPATHY

    Directory of Open Access Journals (Sweden)

    Maji.S, Saha. ML, Kanwar KS, Das S, Bhagat P, Bhar P

    2015-04-01

    Full Text Available ABSTRACT Pheochromocytoma is an extremely uncommon tumor of childhood and there are several features that distinguish its presentation between adults and children. The incidence of pheochromocytoma in childhood is 10% of the adult incidence, occurring in approximately 1 in 500,000 children compared with 1 in 50,000 adults. Around 10% of childhood tumors are familial which is 4times the frequency in adults. Whereas only 7% of pheochromocytomas are bilateral in adults, the reported incidence of the same in children range from 24 % to as high as &70%.These tumors are known for their great diversity in clinical presentation. Greater than 50% of children present with headaches, fever, palpitation, thirst, polyuria, sweating, nausea and weight loss. However the commonest mode of presentation is sustained hypertension. Pheochromocytoma accounts for 0.5% of children with hypertension and must be considered once other causes have been eliminated. We here in report a unique case of a 13 year old girl who initially presented with bilateral hypertensive retinopathy and later found to have a pheochromocytoma on subsequent workup. Hypertensive retinopathy secondary to pheochromocytoma is itself a rare entity whose exact incidence in children is still unknown. This case highlights the importance of routine history, physical examination and measurement of bp. Prompt surgery can reverse the effect of hypertension and lead to good outcome as was evident in our case.

  8. Unique proteomic signatures distinguish macrophages and dendritic cells.

    Directory of Open Access Journals (Sweden)

    Lev Becker

    Full Text Available Monocytes differentiate into heterogeneous populations of tissue macrophages and dendritic cells (DCs that regulate inflammation and immunity. Identifying specific populations of myeloid cells in vivo is problematic, however, because only a limited number of proteins have been used to assign cellular phenotype. Using mass spectrometry and bone marrow-derived cells, we provided a global view of the proteomes of M-CSF-derived macrophages, classically and alternatively activated macrophages, and GM-CSF-derived DCs. Remarkably, the expression levels of half the plasma membrane proteins differed significantly in the various populations of cells derived in vitro. Moreover, the membrane proteomes of macrophages and DCs were more distinct than those of classically and alternatively activated macrophages. Hierarchical cluster and dual statistical analyses demonstrated that each cell type exhibited a robust proteomic signature that was unique. To interrogate the phenotype of myeloid cells in vivo, we subjected elicited peritoneal macrophages harvested from wild-type and GM-CSF-deficient mice to mass spectrometric and functional analysis. Unexpectedly, we found that peritoneal macrophages exhibited many features of the DCs generated in vitro. These findings demonstrate that global analysis of the membrane proteome can help define immune cell phenotypes in vivo.

  9. [Reactive anxiety crisis: a unique case of work injury].

    Science.gov (United States)

    Taino, G; Gazzoldi, T; Marandola, P; Valoti, E; Fabris, F; Imbriani, M

    2007-01-01

    The present study aims to describe a unique case in view of the disease diagnosed, the conditions of onset and the management by INAIL (Italian National Institute of Insurance for Injuries at Work and Occupational Diseases). A worker, after a verbal, animated dispute with some collegues, had an acute psychiatric agitation attack and went to the nearest emergency room, where he was investigated. No neuropsychiatric alteration was diagnosed, but based on anamnestic data, the physicians diagnosed an anxiety crisis reactive to work environment. A medical certificate for injury at work was produced and sent to the Insurance Board (INAIL). The worker was off work for 105 days diagnosed with a persistent anxious depressive syndrome, secondary to the traumatic event. INAIL reassessed the case later and confirmed only the first 30 days as due to work accident, while the following period was judged as related to affectivity disturbance due to common disease, not to work environment. Our case opens new perspective for the occupational physician in the assessment of ASD as work injury and of PTSD as professional disease, suggesting to give more attention to psychiatric health of workers.

  10. Anaerobic Ammonium-Oxidizing Bacteria: Unique Microorganisms with Exceptional Properties

    Science.gov (United States)

    Jetten, Mike S. M.

    2012-01-01

    Summary: Anaerobic ammonium-oxidizing (anammox) bacteria defy many microbiological concepts and share numerous properties with both eukaryotes and archaea. Among their most intriguing characteristics are their compartmentalized cell plan and archaeon-like cell wall. Here we review our current knowledge about anammox cell biology. The anammox cell is divided into three separate compartments by bilayer membranes. The anammox cell consists of (from outside to inside) the cell wall, paryphoplasm, riboplasm, and anammoxosome. Not much is known about the composition or function of both the anammox cell wall and the paryphoplasm compartment. The cell wall is proposed to be proteinaceous and to lack both peptidoglycan and an outer membrane typical of Gram-negative bacteria. The function of the paryphoplasm is unknown, but it contains the cell division ring. The riboplasm resembles the standard cytoplasmic compartment of other bacteria; it contains ribosomes and the nucleoid. The anammoxosome occupies most of the cell volume and is a so-called “prokaryotic organelle” analogous to the eukaryotic mitochondrion. This is the site where the anammox reaction takes place, coupled over the curved anammoxosome membrane, possibly giving rise to a proton motive force and subsequent ATP synthesis. With these unique properties, anammox bacteria are food for thought concerning the early evolution of the domains Bacteria, Archaea, and Eukarya. PMID:22933561

  11. Liposarcoma of Hypopharynx and Esophagus: a Unique Entity?

    Science.gov (United States)

    Riva, Giuseppe; Sensini, Matteo; Corvino, Andrea; Garzaro, Massimiliano; Pecorari, Giancarlo

    2016-06-01

    Liposarcoma is the most common soft tissue sarcoma in adults. It represents approximately 20 % of all mesenchymal malignancies. It most frequently involves retroperitoneum, trunk, and extremities. Hypopharyngeal and esophageal localization of liposarcoma is extremely rare. We performed a systematic review of literature and reported 26 and 33 cases of hypopharyngeal and esophageal liposarcoma. We analyzed natural history, imaging features, histology, treatment, and prognosis, with a specific focus to similarities and differences between tumors of hypopharynx and esophagus. Hypopharyngeal and esophageal liposarcomas have more similarities than differences. Incidence has a peak at 6th and 7th decades. The diagnostic procedures are barium swallow, endoscopic examination, and CT/MR imaging. Well-differentiated liposarcoma represents the most frequent histological subtype. Surgical excision is the main treatment. Endoscopic resection can be useful for pedunculated tumors of hypopharynx and cervical esophagus. Differences between hypopharyngeal and esophageal liposarcoma are represented by local recurrence rate (greater for hypopharyngeal tumors), number of giant tumors, and time to recurrence (greater for esophageal tumors). Finally, liposarcomas of distal esophagus need more extended approaches. Liposarcomas of hypopharynx and cervical esophagus could be considered a unique pathological entity, with similar features and treatment options. Survival rate is dependent on histological type and location. Local recurrence is common, especially for hypopharyngeal liposarcoma, while the risk of lymph node or distant metastasis is very low. Patients should undergo regular examinations to rule out local recurrence, also for a long time, especially for esophageal tumors.

  12. Non-unique monopole oscillations of harmonically confined Yukawa systems

    Science.gov (United States)

    Ducatman, Samuel; Henning, Christian; Kaehlert, Hanno; Bonitz, Michael

    2008-11-01

    Recently it was shown that the Breathing Mode (BM), the mode of uniform radial expansion and contraction, which is well known from harmonically confined Coulomb systems [1], does not exist in general for other systems [2]. As a consequence the monopole oscillation (MO), the radial collective excitation, is not unique, but there are several MO with different frequencies. Within this work we show simulation results of those monopole oscillations of 2-dimensional harmonically confined Yukawa systems, which are known from, e.g., dusty plasma crystals [3,4]. We present the corresponding spectrum of the particle motion, including analysis of the frequencies found, and compare with theoretical investigations.[1] D.H.E. Dubin and J.P. Schiffer, Phys. Rev. E 53, 5249 (1996)[2] C. Henning at al., accepted for publication in Phys. Rev. Lett. (2008)[3] A. Melzer et al., Phys. Rev. Lett. 87, 115002 (2001)[4] M. Bonitz et al., Phys. Rev. Lett. 96, 075001 (2006)

  13. A unique approach to municipal waste management in Chianti, Italy

    International Nuclear Information System (INIS)

    Dhargalkar, P.H.

    1991-01-01

    Innovative solutions are required to manage the growing problem of disposal of municipal waste throughout the world. Recovery of energy by combustion of municipal waste has become an acceptable approach in many communities. A unique system with a capacity of 200 tons of waste per day with simultaneous production of electric power and fuel gas is currently under construction in Greve located in the famous wine region of Chianti, Italy. The refuse-derived fuel will be treated in a fluidized bed gasifier. A portion of the gas produced by the gasifier will be used to produce 6.7 MW of electric power; the remaining gas will be used as a fuel in the neighboring cement plant. The plant will be equipped with a state-of-the-art emission control system including an afterburner, a quench reactor, dry venturi and a fabric filter to minimize emissions to the atmosphere. This is the first plant in Europe to employ the fluidized bed gasifier technology on refuse-derived fuel. Design highlights of the overall plant including the air quality control system are presented in this paper

  14. Brush-Like Polymers: New Design Platforms for Soft, Dry Materials with Unique Property Relations

    Science.gov (United States)

    Daniel, William Francis McKemie, Jr.

    Elastomers represent a unique class of engineering materials due to their light weight, low cost, and desirable combination of softness (105 -107 Pa) and large extensibilities (up to 1000%). Despite these advantages, there exist applications that require many times softer modulus, greater extensibility, and stronger strain hardening for the purpose of mimicking the mechanical properties of systems such as biological tissues. Until recently, only liquid-filled gels were suitable materials for such applications, including soft robotics and implants. A considerable amount of work has been done to create gels with superior properties, but despite unique strengths they also suffer from unique weaknesses. This class of material displays fundamental limitations in the form of heterogeneous structures, solvent loss and phase transitions at extreme temperatures, and loss of liquid fraction upon high deformations. In gels the solvent fraction also introduces a large solvent/polymer interaction parameter which must be carefully considered when designing the final mechanical properties. These energetic considerations further exaggerate the capacity for inconstant mechanical properties caused by fluctuations of the solvent fraction. In order to overcome these weaknesses, a new platform for single component materials with low modulus (Standard networks have one major control factor outside of chemistry, the network stand length. Brush-like architectures are created from long strands with regularly grafted side chains creating three characteristic length scales which may be independently manipulated. In collaboration with M. Rubinstein, we have utilized bottlebrush polymer architectures (a densely grafted brush-like polymer) to experimentally verify theoretical predictions of disentangled bottlebrush melts. By attaching well-defined side chains onto long polymer backbones, individual polymer strands are separated in space (similar to dilution with solvent) accompanied by a

  15. The Multiwavelength Study of Two Unique Radio Galaxies Nectaria ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    They have no compact hotspots and consist of sharply-bounded lobes. They are probably the only two radio galaxies that show large multiple circular radio features (ring-like structures) that are interior to the lobes and not just phenomena of the boundaries. A few of these rings are the largest material circles known ...

  16. Unique features of creative designing at the preschool age

    Directory of Open Access Journals (Sweden)

    Bilа Iryna Mykolayivna

    2017-04-01

    Full Text Available The research is devoted to studying the specificity of creative designing at the preschool age. The author identifies the systematic approach on the design work and creative designing, knowledge adjustment, as well as the assessment criteria and performance indicators of creative designing by children at the preschool age. The article considers the psychological structure of the design activity, clarifies its characteristics and defines the role of each component of creative designing process at the preschool age. As a result of the empirical study it was proved that in the process of understanding the challenges pre-schoolers’s mind makes mental acts of comparison predominant. Their creative intention is determined by the focus on the structural and structural-functional characteristics of the subjects. The whole structure of the pre-schooler’s solution in the process of working with creative tasks on designing is integrated with the individual and regulatory aspect of creative designing that appears in the subjective mental actions, trends, and practice.

  17. A unique bivalent binding and inhibition mechanism by the yatapoxvirus interleukin 18 binding protein.

    Directory of Open Access Journals (Sweden)

    Brian Krumm

    Full Text Available Interleukin 18 (IL18 is a cytokine that plays an important role in inflammation as well as host defense against microbes. Mammals encode a soluble inhibitor of IL18 termed IL18 binding protein (IL18BP that modulates IL18 activity through a negative feedback mechanism. Many poxviruses encode homologous IL18BPs, which contribute to virulence. Previous structural and functional studies on IL18 and IL18BPs revealed an essential binding hot spot involving a lysine on IL18 and two aromatic residues on IL18BPs. The aromatic residues are conserved among the very diverse mammalian and poxviruses IL18BPs with the notable exception of yatapoxvirus IL18BPs, which lack a critical phenylalanine residue. To understand the mechanism by which yatapoxvirus IL18BPs neutralize IL18, we solved the crystal structure of the Yaba-Like Disease Virus (YLDV IL18BP and IL18 complex at 1.75 Å resolution. YLDV-IL18BP forms a disulfide bonded homo-dimer engaging IL18 in a 2∶2 stoichiometry, in contrast to the 1∶1 complex of ectromelia virus (ECTV IL18BP and IL18. Disruption of the dimer interface resulted in a functional monomer, however with a 3-fold decrease in binding affinity. The overall architecture of the YLDV-IL18BP:IL18 complex is similar to that observed in the ECTV-IL18BP:IL18 complex, despite lacking the critical lysine-phenylalanine interaction. Through structural and mutagenesis studies, contact residues that are unique to the YLDV-IL18BP:IL18 binding interface were identified, including Q67, P116 of YLDV-IL18BP and Y1, S105 and D110 of IL18. Overall, our studies show that YLDV-IL18BP is unique among the diverse family of mammalian and poxvirus IL-18BPs in that it uses a bivalent binding mode and a unique set of interacting residues for binding IL18. However, despite this extensive divergence, YLDV-IL18BP binds to the same surface of IL18 used by other IL18BPs, suggesting that all IL18BPs use a conserved inhibitory mechanism by blocking a putative receptor

  18. Unique natural exopolysaccharides for biomimetic protective effect against urban pollution.

    Science.gov (United States)

    Borel, Magali; Lamarque, Elisabeth; Loing, Estelle

    Through natural selection, living organisms have evolved well-adapted survival strategies over time. The shallow salt waters of Moorea lagoon are the site of accumulation of microbial mats called "Kopara," in the native Polynesian language. This unique ecosystem is rich in film-forming exopolysaccharides (EPSs) secreted by microorganisms within the biofilm, as a mean to protect themselves from environmental stress (strong ultraviolet [UV], pH, salinity … ). Using blue biotechnology, a manufacturing process was developed to obtain an EPS with skin benefits. The active ingredient (EPS-229) protects against urban pollution, including free radicals, heavy metals, hydrocarbons, and PM 2.5 (particulate matter with a size lower than 2.5 μm). The anti-lipid peroxidation action of EPS-229 was studied in an in vitro UVB-irradiated keratinocyte culture model, using lipophilic fluorescent probe. The chelating properties of EPS-229 were evaluated in tubo in the presence of cadmium and lead. The protective effect of EPS-229 on pollution-exposed skin explants was investigated through quantification of released malondialdehyde (MDA) and histological observation of skin morphology using optical microscopy. Clinical evaluation of the protective and cleansing efficacy of a water solution containing EPS-229 (0.02% and 0.01% w/v, respectively) was performed, against placebo, on a panel of 18 volunteers. For these studies, the forearms of volunteers were treated with EPS-229 before (anti-adhesion affect) or after (cleansing effect) application of PM 2.5 (iron particles of 1 μm). The presence of skin-adherent particles was observed and quantified by image analysis, using specific digital masks. In vitro , EPS-229 significantly protected keratinocyte cell membranes from lipid peroxidation. A decrease of 28% was achieved when a concentration of 0.001% w/v EPS-229 was applied to the cell culture. In tubo , EPS-229 also presented strong chelating properties. Maximal adsorption was

  19. A unique deubiquitinase that deconjugates phosphoribosyl-linked protein ubiquitination

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Jiazhang; Yu, Kaiwen; Fei, Xiaowen; Liu, Yao; Nakayasu, Ernesto S.; Piehowski, Paul D.; Shaw, Jared B.; Puvar, Kedar; Das, Chittaranjan; Liu, Xiaoyun; Luo, Zhao-Qing

    2017-05-12

    Ubiquitination regulates many aspects of host immunity and thus is a common target for infectious agents. Recent studies revealed that members of the SidE effector family of the bacterial pathogen Legionella pneumophila attacked several small GTPases associated with the endoplasmic reticulum by a novel ubiquitination mechanism that does not require the E1 and E2 enzymes of the host ubiquitination machinery. Following ubiquitin activation by ADP- ribosylation via a mono-ADP-ribosylation motif, ADP-ribosylated ubiquitin is cleaved by a phosphodiesterasedomainwithinSdeA,whichisconcomitantwiththelinkof phosphoribosylated ubiquitin to serine residues in the substrate. Here we demonstrate that the activity of SidEs is regulated by SidJ, another effector encoded by a gene situated in the locus coding for three members of the SidE family (SdeC, SdeB and SdeA). SidJ functions to remove ubiquitin from SidEs-modified substrates by cleaving the phosphodiester bond that links phosphoribosylated ubiquitin to protein substrates. Further, the deubiquitinase activity of SidJ is essential for its role in L. pneumophila infection. Finally, the activity of SidJ is required for efficiently reducing the abundance of ubiquitinated Rab33b in infected cells within a few hours after bacterial uptake. Our results establish SidJ as a deubiquitinase that functions to impose temporal regulation of the activity of the SidE effectors. The identification of SidJ may shed light on future study of signaling cascades mediated by this unique ubiquitination that also potentially regulates cellular processes in eukaryotic cells.

  20. A unique view on male infertility around the globe.

    Science.gov (United States)

    Agarwal, Ashok; Mulgund, Aditi; Hamada, Alaa; Chyatte, Michelle Renee

    2015-04-26

    Infertility affects an estimated 15% of couples globally, amounting to 48.5 million couples. Males are found to be solely responsible for 20-30% of infertility cases and contribute to 50% of cases overall. However, this number does not accurately represent all regions of the world. Indeed, on a global level, there is a lack of accurate statistics on rates of male infertility. Our report examines major regions of the world and reports rates of male infertility based on data on female infertility. Our search consisted of systematic reviews, meta-analyses, and population-based studies by searching the terms "epidemiology, male infertility, and prevalence." We identified 16 articles for detailed study. We typically used the assumption that 50% of all cases of infertility are due to female factors alone, 20-30% are due to male factors alone, and the remaining 20-30% are due to a combination of male and female factors. Therefore, in regions of the world where male factor or rates of male infertility were not reported, we used this assumption to calculate general rates of male factor infertility. Our calculated data showed that the distribution of infertility due to male factor ranged from 20% to 70% and that the percentage of infertile men ranged from 2·5% to 12%. Infertility rates were highest in Africa and Central/Eastern Europe. Additionally, according to a variety of sources, rates of male infertility in North America, Australia, and Central and Eastern Europe varied from 4 5-6%, 9%, and 8-12%, respectively. This study demonstrates a novel and unique way to calculate the distribution of male infertility around the world. According to our results, at least 30 million men worldwide are infertile with the highest rates in Africa and Eastern Europe. Results indicate further research is needed regarding etiology and treatment, reduce stigma & cultural barriers, and establish a more precise calculation.

  1. The uniqueness and complexity of kampung city Bustaman Semarang Indonesia

    Science.gov (United States)

    Sudarwanto, Budi; Hardiman, Gagoek; Suprapti, Atiek; Sarjono, Agung B.

    2017-12-01

    The purpose of this study is to describe the uniqueness and complexity of one village town Bustaman Semarang Indonesia. This research is in the domain of qualitative research paradigm with ethnography research strategy. The critical ethnography technique is chosen with the consideration of the purpose of this research, that is besides describing also the analysing urban spatial condition over its complexity. Bustaman town village has artifacts outdated and local economic activities namely culinary processed goat meat. Kampung Bustaman shows the common character as a city hometown, which is chaotic and shabby. Some artifacts and historical value of Bustaman village as well as community culture become potential to be developed and conserved. But for that the quality of Bustaman village hometown should be improved. Bustaman's urban halls are under distress by changes in urban modernization, including the pattern of life of Bustaman villagers. However, the existing phenomenon that the potential of local and cultural communities are still able to survive and exist, within the limitations of space and resources available. The process of culinary production of goat meat, the limitation of the kampong space, the social awareness of the villagers, the role of community leaders, and the necessities of daily life are the drivers of the complexity of Bustaman village space. The village road corridor and the house terrace become the victim room for all the activities of the town. Clutter seems clear can be found in every corner of Bustaman village space. Kampung Bustaman can be categorized as a spontaneous and compact informal village, but still survive on the urban spatial locality.

  2. Development of a Unique Small Molecule Modulator of CXCR4

    Science.gov (United States)

    Yoon, Younghyoun; Lin, Songbai; Sasaki, Maiko; Klapproth, Jan-Michael A.; Yang, Hua; Grossniklaus, Hans E.; Xu, Jianguo; Rojas, Mauricio; Voll, Ronald J.; Goodman, Mark M.; Arrendale, Richard F.; Liu, Jin; Yun, C. Chris; Snyder, James P.; Liotta, Dennis C.; Shim, Hyunsuk

    2012-01-01

    Background Metastasis, the spread and growth of tumor cells to distant organ sites, represents the most devastating attribute and plays a major role in the morbidity and mortality of cancer. Inflammation is crucial for malignant tumor transformation and survival. Thus, blocking inflammation is expected to serve as an effective cancer treatment. Among anti-inflammation therapies, chemokine modulation is now beginning to emerge from the pipeline. CXC chemokine receptor-4 (CXCR4) and its ligand stromal cell-derived factor-1 (CXCL12) interaction and the resulting cell signaling cascade have emerged as highly relevant targets since they play pleiotropic roles in metastatic progression. The unique function of CXCR4 is to promote the homing of tumor cells to their microenvironment at the distant organ sites. Methodology/Principal Findings We describe the actions of N,N′-(1,4-phenylenebis(methylene))dipyrimidin-2-amine (designated MSX-122), a novel small molecule and partial CXCR4 antagonist with properties quite unlike that of any other reported CXCR4 antagonists, which was prepared in a single chemical step using a reductive amination reaction. Its specificity toward CXCR4 was tested in a binding affinity assay and a ligand competition assay using 18F-labeled MSX-122. The potency of the compound was determined in two functional assays, Matrigel invasion assay and cAMP modulation. The therapeutic potential of MSX-122 was evaluated in three different murine models for inflammation including an experimental colitis, carrageenan induced paw edema, and bleomycin induced lung fibrosis and three different animal models for metastasis including breast cancer micrometastasis in lung, head and neck cancer metastasis in lung, and uveal melanoma micrometastasis in liver in which CXCR4 was reported to play crucial roles. Conclusions/Significance We developed a novel small molecule, MSX-122, that is a partial CXCR4 antagonist without mobilizing stem cells, which can be safer for

  3. Development of a unique small molecule modulator of CXCR4.

    Directory of Open Access Journals (Sweden)

    Zhongxing Liang

    Full Text Available Metastasis, the spread and growth of tumor cells to distant organ sites, represents the most devastating attribute and plays a major role in the morbidity and mortality of cancer. Inflammation is crucial for malignant tumor transformation and survival. Thus, blocking inflammation is expected to serve as an effective cancer treatment. Among anti-inflammation therapies, chemokine modulation is now beginning to emerge from the pipeline. CXC chemokine receptor-4 (CXCR4 and its ligand stromal cell-derived factor-1 (CXCL12 interaction and the resulting cell signaling cascade have emerged as highly relevant targets since they play pleiotropic roles in metastatic progression. The unique function of CXCR4 is to promote the homing of tumor cells to their microenvironment at the distant organ sites.We describe the actions of N,N'-(1,4-phenylenebis(methylenedipyrimidin-2-amine (designated MSX-122, a novel small molecule and partial CXCR4 antagonist with properties quite unlike that of any other reported CXCR4 antagonists, which was prepared in a single chemical step using a reductive amination reaction. Its specificity toward CXCR4 was tested in a binding affinity assay and a ligand competition assay using (18F-labeled MSX-122. The potency of the compound was determined in two functional assays, Matrigel invasion assay and cAMP modulation. The therapeutic potential of MSX-122 was evaluated in three different murine models for inflammation including an experimental colitis, carrageenan induced paw edema, and bleomycin induced lung fibrosis and three different animal models for metastasis including breast cancer micrometastasis in lung, head and neck cancer metastasis in lung, and uveal melanoma micrometastasis in liver in which CXCR4 was reported to play crucial roles.We developed a novel small molecule, MSX-122, that is a partial CXCR4 antagonist without mobilizing stem cells, which can be safer for long-term blockade of metastasis than other reported CXCR4

  4. The gaming of concussions: a unique intervention in postconcussion syndrome.

    Science.gov (United States)

    Lynch, James M; Anderson, Megan; Benton, Brooke; Green, Sue Stanley

    2015-03-01

    To present the case of 2 adolescent high school student-athletes who developed postconcussion syndrome with protracted and limiting visual complaints that markedly affected academic, social, and athletic activity for a year after the onset of symptoms. Both had significant improvement soon after a unique intervention was administered. A 14-year-old female soccer and softball player sustained 2 concussions in the same week. She had persistent symptoms for a year that affected her grades and precluded athletic participation. A 15-year-old male football player sustained a concussion during an altercation with 2 other male adolescents. He continued to have symptoms 1 year later, with a marked decrease in academic performance and restriction from athletics. Both adolescents reported blurry vision, photophobia, and associated headache as significant components of the postconcussion syndrome. Concussion, postconcussion syndrome, skull fracture, subdural hematoma, epidural hematoma, second-impact syndrome, and visually sensitive migraine. Both patients were advised to obtain computer gaming glasses to use throughout the day. The female patient was diligent in her use of the glasses, with marked lessening of symptoms. The male patient was less accepting of the glasses but did report lessening of symptoms when using the glasses. We hypothesized that postconcussion syndrome with marked visual complaints would respond to and improve with decreased stimulation of the visual system. This was attempted with the addition of computer gaming glasses. Both adolescent athletes responded well to the filtering of visual stimuli by off-the-shelf computer gaming glasses. Postconcussion syndrome is a persistent condition with a myriad of symptoms. Two young athletes developed postconcussion syndrome with prominent visual symptoms that lasted a year. The addition of computer gaming glasses markedly lessened symptoms in both patients.

  5. Biomarkers on Europa: Unique signatures produced by radiolysis?

    Science.gov (United States)

    Carlson, R. W.; Hand, K. P.

    A promising habitat for life is Jupiter's moon Europa, with its likely ocean under a young, active surface. Europa orbits in the heart of Jupiter's powerful magnetosphere and suffers intense energetic particle bombardment, producing both good and bad aspects for astrobiology at Europa. Ionizing radiation can produce oxidants that could support a radiation-driven ecology as proposed by Chyba. On the other hand, biomolecular evidence for oceanic life that may be emplaced on the surface is rapidly altered by radiation, perhaps complicating astrobiological searches for evidence of life. We are studying the radiolytic degradation of molecular biomarkers in ice at Europa temperatures by studying both simple organics and more complex biomolecules, including microorganisms. High energy (1-100 keV) electron irradiation is employed and the products are analyzed using infrared spectroscopy, thermal desorption mass spectroscopy, and laser desorption/ionization mass spectroscopy. Hydrocarbon radiolysis yields carbon dioxide and methane which can escape the system and results in the net loss of carbon. Aliphatic molecules with C=O bonds are formed and thought to be mainly polymethylene oxides. When heated, they polymerize to form brown, high-molecular-weight refractory residues with linear, spherical, and ring- shaped macrostructures, typically many tens of micrometers in size. Laser desorption mass spectra of the residues are not overly complex and are different for each initial species. Radiolysis of microorganisms shows the destruction of amine, amide, methyl, and methylene groups, and production of carbon dioxide, carbon monoxide, nitriles, and isocyanates. Mass spectra of irradiated B. pumilus spores are different and surprisingly less complex than those of unirradiated spores. It is possible that unique, diagnostic biosignatures may exist in mass spectra of irradiated microorganisms.

  6. Grasping convergent evolution in syngnathids: a unique tale of tails

    Science.gov (United States)

    Neutens, C; Adriaens, D; Christiaens, J; De Kegel, B; Dierick, M; Boistel, R; Van Hoorebeke, L

    2014-01-01

    Seahorses and pipehorses both possess a prehensile tail, a unique characteristic among teleost fishes, allowing them to grasp and hold onto substrates such as sea grasses. Although studies have focused on tail grasping, the pattern of evolutionary transformations that made this possible is poorly understood. Recent phylogenetic studies show that the prehensile tail evolved independently in different syngnathid lineages, including seahorses, Haliichthys taeniophorus and several types of so-called pipehorses. This study explores the pattern that characterizes this convergent evolution towards a prehensile tail, by comparing the caudal musculoskeletal organization, as well as passive bending capacities in pipefish (representing the ancestral state), pipehorse, seahorse and H. taeniophorus. To study the complex musculoskeletal morphology, histological sectioning, μCT-scanning and phase contrast synchrotron scanning were combined with virtual 3D-reconstructions. Results suggest that the independent evolution towards tail grasping in syngnathids reflects at least two quite different strategies in which the ancestral condition of a heavy plated and rigid system became modified into a highly flexible one. Intermediate skeletal morphologies (between the ancestral condition and seahorses) could be found in the pygmy pipehorses and H. taeniophorus, which are phylogenetically closely affiliated with seahorses. This study suggests that the characteristic parallel myoseptal organization as already described in seahorse (compared with a conical organization in pipefish and pipehorse) may not be a necessity for grasping, but represents an apomorphy for seahorses, as this pattern is not found in other syngnathid species possessing a prehensile tail. One could suggest that the functionality of grasping evolved before the specialized, parallel myoseptal organization seen in seahorses. However, as the grasping system in pipehorses is a totally different one, this cannot be

  7. Understanding the unique assembly history of central group galaxies

    International Nuclear Information System (INIS)

    Vulcani, Benedetta; Bundy, Kevin; Lackner, Claire; Leauthaud, Alexie; Treu, Tommaso; Mei, Simona; Coccato, Lodovico; Kneib, Jean Paul; Auger, Matthew; Nipoti, Carlo

    2014-01-01

    Central galaxies (CGs) in massive halos live in unique environments with formation histories closely linked to that of the host halo. In local clusters, they have larger sizes (R e ) and lower velocity dispersions (σ) at fixed stellar mass M * , and much larger R e at a fixed σ than field and satellite galaxies (non-CGs). Using spectroscopic observations of group galaxies selected from the COSMOS survey, we compare the dynamical scaling relations of early-type CGs and non-CGs at z ∼ 0.6 to distinguish possible mechanisms that produce the required evolution. CGs are systematically offset toward larger R e at fixed σ compared to non-CGs with similar M * . The CG R e -M * relation also shows differences, primarily driven by a subpopulation (∼15%) of galaxies with large R e , while the M * -σ relations are indistinguishable. These results are accentuated when double Sérsic profiles, which better fit light in the outer regions of galaxies, are adopted. They suggest that even group-scale CGs can develop extended components by these redshifts that can increase total R e and M * estimates by factors of ∼2. To probe the evolutionary link between our sample and cluster CGs, we also analyze two cluster samples at z ∼ 0.6 and z ∼ 0. We find similar results for the more massive halos at comparable z, but much more distinct CG scaling relations at low-z. Thus, the rapid, late-time accretion of outer components, perhaps via the stripping and accretion of satellites, would appear to be a key feature that distinguishes the evolutionary history of CGs.

  8. Unique Assessment of Hand Surgery Knowledge by Specialty.

    Science.gov (United States)

    Silvestre, Jason; Lin, Ines C; Chang, Benjamin; Levin, L Scott

    2016-03-01

    Orthopedic and plastic surgery residents receive unique training yet often compete for similar hand surgery fellowships. This study compared didactic hand surgery training during orthopedic and plastic surgery residency. The Plastic Surgery In-Service Training Exam and Orthopaedic In-Training Examination were analyzed for hand content for the years 2009 to 2013. Topics were categorized with the content outline for the Surgery of the Hand Examination. Differences were elucidated by means of Fisher's exact test. Relative to the Orthopaedic In-Training Examination, the Plastic Surgery In-Service Training Exam had greater hand representation (20.3 percent versus 8.1 percent; p < 0.001) with more annual hand questions (40 ± 3 versus 24 ± 2; p < 0.001). The Plastic Surgery Exam questions had more words, were less often level I-recall type, and were less often image-based. The questions focused more on finger and hand/palm anatomy, whereas the Orthopaedic examination was more wrist-focused. The Plastic Surgery Exam emphasized wound management and muscle/tendon injuries, but underemphasized fractures/dislocations. References differed, but Journal of Hand Surgery (American Volume) and Green's Operative Hand Surgery were common on both examinations. The Plastic Surgery Exam had a greater publication lag for journal references (10.7 ± 0.5 years versus 9.0 ± 0.6; p = 0.035). Differences in didactic hand surgery training are elucidated for plastic surgery and orthopedic residents. Deficiencies in the Plastic Surgery In-Service Training Exam hand curriculum relative to the Orthopaedic In-Training Examination may underprepare plastic surgeons for the Surgery of the Hand Examination. These data may assist future modifications to hand surgery training in the United States.

  9. Diverticulitis exclusiva de ciego Unique diverticulitis of the cecum

    Directory of Open Access Journals (Sweden)

    Jorge Eduardo Frías Espinosa

    2012-12-01

    Full Text Available La diverticulitis cecal es una rara entidad de difícil diagnóstico que con frecuencia se confunde con un proceso apendicular agudo. Los divertículos primarios o de origen congénito, generalmente son únicos, suelen presentarse en una edad más temprana que la enfermedad diverticular cólica (divertículos secundarios.La presencia de estos en el colon derecho se reporta con menor frecuencia, su diagnóstico es en muchas ocasiones indistinguible de la apendicitis aguda y se realiza en la mayoría de los casos durante la laparotomía, el tratamiento es variable, según la literatura abarca desde la resección del divertículo hasta la hemicolectomía derecha. El objetivo de esta presentación es referir la dificultad diagnostica y la alta frecuencia de error diagnóstico que presenta esta entidad.The cecal diverticulitis is a strange disease, difficult to be diagnosed, frequently confused with acute appendicular process. The primary diverticula or those of congenital origin are generally unique; they usually appear at younger age than the colic diverticular disease (secondary diverticula. Their presence in the right colon is less frequently reported, the diagnosis is often confused with that of acute appendicitis and most of cases undergo laparatomy. According to the scientific literature, the treatment is variable, ranging from diverticular resection to right hemi-cholectomy. The objective of this paper was to present the difficulties and the high frequency of errors in diagnosing this disease.

  10. Unique Three-Dimensional InP Nanopore Arrays for Improved Photoelectrochemical Hydrogen Production.

    Science.gov (United States)

    Li, Qiang; Zheng, Maojun; Ma, Liguo; Zhong, Miao; Zhu, Changqing; Zhang, Bin; Wang, Faze; Song, Jingnan; Ma, Li; Shen, Wenzhong

    2016-08-31

    Ordered three-dimensional (3D) nanostructure arrays hold promise for high-performance energy harvesting and storage devices. Here, we report the fabrication of InP nanopore arrays (NPs) in unique 3D architectures with excellent light trapping characteristic and large surface areas for use as highly active photoelectrodes in photoelectrochemical (PEC) hydrogen evolution devices. The ordered 3D NPs were scalably synthesized by a facile two-step etching process of (1) anodic etching of InP in neutral 3 M NaCl electrolytes to realize nanoporous structures and (2) wet chemical etching in HCl/H3PO4 (volume ratio of 1:3) solutions for removing the remaining top irregular layer. Importantly, we demonstrated that the use of neutral electrolyte of NaCl instead of other solutions, such as HCl, in anodic etching of InP can significantly passivate the surface states of 3D NPs. As a result, the maximum photoconversion efficiency obtained with ∼15.7 μm thick 3D NPs was 0.95%, which was 7.3 and 1.4 times higher than that of planar and 2D NPs. Electrochemical impedance spectroscopy and photoluminescence analyses further clarified that the improved PEC performance was attributed to the enhanced charge transfer across 3D NPs/electrolyte interfaces, the improved charge separation at 3D NPs/electrolyte junction, and the increased PEC active surface areas with our unique 3D NP arrays.

  11. Uniqueness for cross-diffusion systems issuing from seawater intrusion problems

    Directory of Open Access Journals (Sweden)

    Catherine Choquet

    2017-10-01

    Full Text Available We consider a model mixing sharp and diffuse interface approaches for seawater intrusion phenomenons in confined and unconfined aquifers. More precisely, a phase field model is introduced in the boundary conditions on the virtual sharp interfaces. We thus include in the model the existence of diffuse transition zones but we preserve the simplified structure allowing front tracking. The three-dimensional problem then reduces to a two-dimensional model involving a strongly coupled system of partial differential equations of parabolic and elliptic type describing the evolution of the depth of the interface between salt- and freshwater and the evolution of the freshwater hydraulic head. Assuming a low hydraulic conductivity inside the aquifer, we prove the uniqueness of a weak solution for the model completed with initial and boundary conditions. Thanks to a generalization of a Meyer's regularity result, we establish that the gradient of the solution belongs to the space $L^r$, r>2. This additional regularity combined with the Gagliardo-Nirenberg inequality for r=4 allows to handle the nonlinearity of the system in the proof of uniqueness.

  12. Unique competitive effects of lianas and trees in a tropical forest understory.

    Science.gov (United States)

    Wright, Alexandra; Tobin, Mike; Mangan, Scott; Schnitzer, Stefan A

    2015-02-01

    Lianas are an important component of tropical forests, contributing up to 25% of the woody stems and 35% of woody species diversity. Lianas invest less in structural support but more in leaves compared to trees of similar biomass. These physiological and morphological differences suggest that lianas may interact with neighboring plants in ways that are different from similarly sized trees. However, the vast majority of past liana competition studies have failed to identify the unique competitive effects of lianas by controlling for the amount of biomass removed. We assessed liana competition in the forest understory over the course of 3 years by removing liana biomass and an equal amount of tree biomass in 40 plots at 10 sites in a secondary tropical moist forest in central Panama. We found that growth of understory trees and lianas, as well as planted seedlings, was limited due to competitive effects from both lianas and trees, though the competitive impacts varied by species, season, and size of neighbors. The removal of trees resulted in greater survival of planted seedlings compared to the removal of lianas, apparently related to a greater release from competition for light. In contrast, lianas had a species-specific negative effect on drought-tolerant Dipteryx oleifera seedlings during the dry season, potentially due to competition for water. We conclude that, at local scales, lianas and trees have unique and differential effects on understory dynamics, with lianas potentially competing more strongly during the dry season, and trees competing more strongly for light.

  13. High spin polarization and the origin of unique ferromagnetic ground state in CuFeSb

    International Nuclear Information System (INIS)

    Sirohi, Anshu; Saha, Preetha; Gayen, Sirshendu; Gaurav, Abhishek; Jyotsna, Shubhra; Sheet, Goutam; Singh, Chandan K.; Kabir, Mukul; Thakur, Gohil S.; Haque, Zeba; Gupta, L. C.; Ganguli, Ashok K.

    2016-01-01

    CuFeSb is isostructural to the ferro-pnictide and chalcogenide superconductors and it is one of the few materials in the family that are known to stabilize in a ferromagnetic ground state. Majority of the members of this family are either superconductors or antiferromagnets. Therefore, CuFeSb may be used as an ideal source of spin polarized current in spin-transport devices involving pnictide and the chalcogenide superconductors. However, for that the Fermi surface of CuFeSb needs to be sufficiently spin polarized. In this paper we report direct measurement of transport spin polarization in CuFeSb by spin-resolved Andreev reflection spectroscopy. From a number of measurements using multiple superconducting tips we found that the intrinsic transport spin polarization in CuFeSb is high (∼47%). In order to understand the unique ground state of CuFeSb and the origin of large spin polarization at the Fermi level, we have evaluated the spin-polarized band structure of CuFeSb through first principles calculations. Apart from supporting the observed 47% transport spin polarization, such calculations also indicate that the Sb-Fe-Sb angles and the height of Sb from the Fe plane are strikingly different for CuFeSb than the equivalent parameters in other members of the same family thereby explaining the origin of the unique ground state of CuFeSb.

  14. High spin polarization and the origin of unique ferromagnetic ground state in CuFeSb

    Energy Technology Data Exchange (ETDEWEB)

    Sirohi, Anshu; Saha, Preetha; Gayen, Sirshendu; Gaurav, Abhishek; Jyotsna, Shubhra; Sheet, Goutam, E-mail: goutam@iisermohali.ac.in [Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S. A. S. Nagar, Manauli PO 140306 (India); Singh, Chandan K.; Kabir, Mukul [Department of Physics, Indian Institute of Science Education and Research, Pune 411008 (India); Thakur, Gohil S.; Haque, Zeba; Gupta, L. C. [Department of Chemistry, Indian Institute of Technology, New Delhi 110016 (India); Ganguli, Ashok K. [Department of Chemistry, Indian Institute of Technology, New Delhi 110016 (India); Institute of Nano Science & Technology, Mohali 160064 (India)

    2016-06-13

    CuFeSb is isostructural to the ferro-pnictide and chalcogenide superconductors and it is one of the few materials in the family that are known to stabilize in a ferromagnetic ground state. Majority of the members of this family are either superconductors or antiferromagnets. Therefore, CuFeSb may be used as an ideal source of spin polarized current in spin-transport devices involving pnictide and the chalcogenide superconductors. However, for that the Fermi surface of CuFeSb needs to be sufficiently spin polarized. In this paper we report direct measurement of transport spin polarization in CuFeSb by spin-resolved Andreev reflection spectroscopy. From a number of measurements using multiple superconducting tips we found that the intrinsic transport spin polarization in CuFeSb is high (∼47%). In order to understand the unique ground state of CuFeSb and the origin of large spin polarization at the Fermi level, we have evaluated the spin-polarized band structure of CuFeSb through first principles calculations. Apart from supporting the observed 47% transport spin polarization, such calculations also indicate that the Sb-Fe-Sb angles and the height of Sb from the Fe plane are strikingly different for CuFeSb than the equivalent parameters in other members of the same family thereby explaining the origin of the unique ground state of CuFeSb.

  15. A Unique Case of Relapsing Polychondritis Presenting with Acute Pericarditis

    Directory of Open Access Journals (Sweden)

    John V. Higgins

    2013-01-01

    Full Text Available Relapsing polychondritis (RP is an inflammatory disease of the cartilaginous tissue primarily affecting the cartilaginous structures of the ear, nose, joints, and the respiratory system. Cardiovascular complications of RP are associated with high morbidity and mortality and occur most commonly as valvular disease. Pericarditis is a less common complication, occurring in 4% of patients with RP and has not previously been described at presentation. We describe a case of relapsing polychondritis with acute pericarditis at presentation.

  16. Total Quality Management: A Unique Challenge For Behavioral Science Researchers,

    Science.gov (United States)

    Quality Management (TQM) programs in industry and government. The essence of TQM involves respect for personal choice and the participation of every level of workers in decisions which impact the organization. Typically, structured questionnaires developed by behavioral scientists are designed to be easy to summarize and generally lack any mechanism for personal comments, ideas, and suggestions. New open-ended, interactive, and iterative survey methodologies are needed to enhance creativity, encourage feedback, and foster a sense of participation. Total Quality

  17. [Family of ribosomal proteins S1 contains unique conservative domain].

    Science.gov (United States)

    Deriusheva, E I; Machulin, A V; Selivanova, O M; Serdiuk, I N

    2010-01-01

    Different representatives of bacteria have different number of amino acid residues in the ribosomal proteins S1. This number varies from 111 (Spiroplasma kunkelii) to 863 a.a. (Treponema pallidum). Traditionally and for lack of this protein three-dimensional structure, its architecture is represented as repeating S1 domains. Number of these domains depends on the protein's length. Domain's quantity and its boundaries data are contained in the specialized databases, such as SMART, Pfam and PROSITE. However, for the same object these data may be very different. For search of domain's quantity and its boundaries, new approach, based on the analysis of dicted secondary structure (PsiPred), was used. This approach allowed us to reveal structural domains in amino acid sequences of S1 proteins and at that number varied from one to six. Alignment of S1 proteins, containing different domain's number, with the S1 RNAbinding domain of Escherichia coli PNPase elicited a fact that in family of ribosomal proteins SI one domain has maximal homology with S1 domain from PNPase. This conservative domain migrates along polypeptide chain and locates in proteins, containing different domain's number, according to specified pattern. In this domain as well in the S1 domain from PNPase, residues Phe-19, Phe-22, His-34, Asp-64 and Arg-68 are clustered on the surface and formed RNA binding site.

  18. Discovery of a Potent Class of PI3Kα Inhibitors with Unique Binding Mode via Encoded Library Technology (ELT).

    Science.gov (United States)

    Yang, Hongfang; Medeiros, Patricia F; Raha, Kaushik; Elkins, Patricia; Lind, Kenneth E; Lehr, Ruth; Adams, Nicholas D; Burgess, Joelle L; Schmidt, Stanley J; Knight, Steven D; Auger, Kurt R; Schaber, Michael D; Franklin, G Joseph; Ding, Yun; DeLorey, Jennifer L; Centrella, Paolo A; Mataruse, Sibongile; Skinner, Steven R; Clark, Matthew A; Cuozzo, John W; Evindar, Ghotas

    2015-05-14

    In the search of PI3K p110α wild type and H1047R mutant selective small molecule leads, an encoded library technology (ELT) campaign against the desired target proteins was performed which led to the discovery of a selective chemotype for PI3K isoforms from a three-cycle DNA encoded library. An X-ray crystal structure of a representative inhibitor from this chemotype demonstrated a unique binding mode in the p110α protein.

  19. Swimming performance and unique wake topology of the sea hare (Aplysia)

    Science.gov (United States)

    Zhou, Zhuoyu; Mittal, Rajat

    2018-03-01

    The Aplysia, commonly referred to as the "sea hare," is a marine mollusc that swims using large-amplitude flapping of its wide, winglike parapodia. In this study, flow simulations with a relatively simple kinematical model are used to gain insights into the vortex dynamics, thrust generation, and energetics of locomotion for this animal. A unique vortex pattern characterized by three distinct trains of vortex ringlike structures is observed in the wake of this animal. These vortex rings are associated with a positive momentum flux in the wake that counteracts the drag generated by the body. Simulations indicate propulsive efficiencies of up to 24% and terminal swimming speeds of about 0.9 body length per cycle. Swimming speeds are found to increase with increasing parapodial flapping amplitude as well as wavelength of undulation.

  20. Curcumolide, a unique sesquiterpenoid with anti-inflammatory properties from Curcuma wenyujin.

    Science.gov (United States)

    Dong, Jianyong; Shao, Weiwei; Yan, Pengcheng; Cai, Xiaoqing; Fang, Lianglian; Zhao, Xiaowei; Lin, Weiwei; Cai, Yuan

    2015-01-15

    Curcumolide, a novel sesquiterpenoid with a unique 5/6/5 tricyclic skeleton, was isolated from Curcuma wenyujin. The structure and absolute configuration were elucidated by extensive NMR, ECD data analysis, and a single-crystal X-ray study. This molecule exhibited significant anti-inflammatory effects in LPS-induced RAW 264.7 macrophages. It suppressed LPS-induced NF-κB activation, including the nuclear translocation and DNA binding activity of NF-κB, and decreased tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), nitric oxide (NO) and reactive oxygen species (ROS) production. Therefore, Curcumolide may have therapeutic potential for treating inflammatory diseases by inhibiting NF-κB activation and pro-inflammatory mediator production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. STATE-OWNED RURAL BANK PERFORMANCE: DO GOVERNMENT OWNERSHIP AND CORPORATE GOVERNANCE UNIQUENESS MATTER?

    Directory of Open Access Journals (Sweden)

    Azilsyah Noerdin

    2016-12-01

    Full Text Available It has been widely recognized that ownership structure has an impact on firm performance. This paper examines whether rural banks owned by government have poorer performance than those owned by private parties with the emphasis on corporate governance uniqueness of state-owned rural banks. 42 rural banks in Indonesia has been selected as the sample. MANOVA test is used to investigate the difference performance between the two types of the rural banks. The results show that state-owned rural banks perform poorer than their privately-owned counterparts. It is indicated by lower ROA ratio and higher OEOI and NPL ratios. The important implication of this finding suggets that government ownership impede boards of rural banks to implement good corporate governance practices in order to improve their banks performance.

  2. Radioimmunochemical characterization of hemoglobins Lepore and Kenya: unique antigenic determinants located on hybrid hemoglobins

    International Nuclear Information System (INIS)

    Garver, F.A.; Altay, G.; Baker, M.M.; Gravely, M.; Huisman, T.H.J.

    1978-01-01

    Antisera were produced in rabbits to the three known types of Lepore hemoglobins, which contain hybrid delta-β non-α-chains, and to hemoglobin Kenya, which has a hybrid γ-β non-α-chain. By using a sensitive radioimmunoassay technique, the absorbed antisera were shown to contain an antibody population that was specific for the hybrid hemoglobin and did not cross-react with normal hemoglobins. However, with the absorbed Lepore-specific antisera, the three known types of Lepore hemoglobins were antigenically indistinguishable from each other, suggesting that antibodies are not produced to the primary structural differences which define the three non-α-chains of the Lepore hemoglobins. These studies demonstrate that the non-α-subunits of hemoglobins Lepore and Kenya possess unique antigenic determinant sites, evidently resulting from an altered polypeptide conformation

  3. Revealing a steroid receptor ligand as a unique PPAR[gamma] agonist

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Shengchen; Han, Ying; Shi, Yuzhe; Rong, Hui; Zheng, Songyang; Jin, Shikan; Lin, Shu-Yong; Lin, Sheng-Cai; Li, Yong (Pitt); (Xiamen)

    2012-06-28

    Peroxisome proliferator-activated receptor gamma (PPAR{gamma}) regulates metabolic homeostasis and is a molecular target for anti-diabetic drugs. We report here the identification of a steroid receptor ligand, RU-486, as an unexpected PPAR{gamma} agonist, thereby uncovering a novel signaling route for this steroid drug. Similar to rosiglitazone, RU-486 modulates the expression of key PPAR{gamma} target genes and promotes adipocyte differentiation, but with a lower adipogenic activity. Structural and functional studies of receptor-ligand interactions reveal the molecular basis for a unique binding mode for RU-486 in the PPAR{gamma} ligand-binding pocket with distinctive properties and epitopes, providing the molecular mechanisms for the discrimination of RU-486 from thiazolidinediones (TZDs) drugs. Our findings together indicate that steroid compounds may represent an alternative approach for designing non-TZD PPAR{gamma} ligands in the treatment of insulin resistance.

  4. A Review on Graphene-Based Gas/Vapor Sensors with Unique Properties and Potential Applications

    Institute of Scientific and Technical Information of China (English)

    Tao Wang; Da Huang; Zhi Yang; Shusheng Xu; Guili He; Xiaolin Li; Nantao Hu; Guilin Yin; Dannong He; Liying Zhang

    2016-01-01

    Graphene-based gas/vapor sensors have attracted much attention in recent years due to their variety of structures, unique sensing performances, room-temperature working conditions, and tremendous application prospects, etc.Herein, we summarize recent advantages in graphene preparation, sensor construction, and sensing properties of various graphene-based gas/vapor sensors, such as NH3, NO2, H2, CO, SO2, H2S, as well as vapor of volatile organic compounds.The detection mechanisms pertaining to various gases are also discussed. In conclusion part, some existing problems which may hinder the sensor applications are presented. Several possible methods to solve these problems are proposed, for example, conceived solutions, hybrid nanostructures, multiple sensor arrays, and new recognition algorithm.

  5. Evolution PDEs with nonstandard growth conditions existence, uniqueness, localization, blow-up

    CERN Document Server

    Antontsev, Stanislav

    2015-01-01

    This monograph offers the reader a treatment of the theory of evolution PDEs with nonstandard growth conditions. This class includes parabolic and hyperbolic equations with variable or anisotropic nonlinear structure. We develop methods for the study of such equations and present a detailed account of recent results. An overview of other approaches to the study of PDEs of this kind is provided. The presentation is focused on the issues of existence and uniqueness of solutions in appropriate function spaces, and on the study of the specific qualitative properties of solutions, such as localization in space and time, extinction in a finite time and blow-up, or nonexistence of global in time solutions. Special attention is paid to the study of the properties intrinsic to solutions of equations with nonstandard growth.

  6. Uniqueness of exterior axisymmetric solution for a rotating charged body in the relativistic theory of gravitation

    International Nuclear Information System (INIS)

    Karabut, P.V.; Chugreev, Yu.V.

    1989-01-01

    The relativistic theory of gravitation (RTG), which is constructed on the basis of Minkowski spacetime, the geometrization principle, and the notion of the gravitational field var-phi mn as a physical field in the spirit of Faraday and Maxwell, explains all known gravitational experiments and gives a new prediction for the evolution of the universe, collapse, etc. The RTG determines the structure of the gravitational field as a field possessing spins 2 and 0 and all conservation laws for energy, momentum, and angular momentum. An exact solution of the complete simultaneous system of equations of the relativistic theory of gravitation and Maxwell's equations is found in the axisymmetric case for an electrically charged rotating body. The uniqueness of this solution is proved

  7. Unique small RNA signatures uncovered in the tammar wallaby genome

    Directory of Open Access Journals (Sweden)

    Lindsay James

    2012-10-01

    discovered crasiRNAs. These small RNAs are derived largely from centromere-enriched retroelements, including a novel SINE. Conclusions This study encompasses the first analyses of the major classes of small RNAs for the newly completed tammar genome, validates preliminary annotations using deep sequencing and computational approaches, and provides a foundation for future work on tammar-specific as well as conserved, but previously unknown small RNA progenitors and targets identified herein. The characterization of new miRNA target genes and a unique profile for crasiRNAs has allowed for insight into multiple RNA mediated processes in the tammar, including gene regulation, species incompatibilities, centromere and chromosome function.

  8. Saving a Unique Data Set for Space Weather Research

    Science.gov (United States)

    Bilitza, D.; Benson, R. F.; Reinisch, B. W.; Huang, X. A.

    2017-12-01

    The Canadian/US International Satellites for Ionospheric Studies (ISIS) program included the four satellites Alouette 1 and 2, ISIS 1 and 2 launched in 1962, 1965, 1969, and 1971, respectively and in operation for 10, 10, 21, and 19 years, respectively. The core experiment on these satellites was a topside sounder that could determine the ionospheric electron density from the orbit altitude down to about 250-500 km near where the ionosphere reaches its point of highest density, the F-peak. The mission was long lasting and highly successful, producing a wealth of information about the topside ionosphere in the form of analog ionosphere soundings on 7-track tapes. The analysis process required a tedious manual scaling of ionogram traces that could then, with appropriate software, be converted into electron density profiles. Even with the combined effort involving ionospheric groups from many countries only a relatively small percentage of the huge volume of recorded ionograms could be converted to electron density profiles. Even with this limited number significant new insights were achieved documented by the many Alouette/ISIS-related papers published in the 1960s and 1970s. Recognizing the importance of this unique data set for space weather research a new effort was undertaken in the late Nineties to analyze more of the Alouette/ISIS ionograms. The immediate cause for action was the threat to the more than 100,000 analog telemetry tapes in storage in Canada because of space limitations and storage costs. We were able to have nearly 20,000 tapes shipped to the NASA Goddard Space Flight Center for analog-to-digital conversion and succeeded in developing software that automatically scales and converts the ionograms to electron density profiles. This rescue effort is still ongoing and has already produced a significant increase in the information available for the topside ionosphere and has resulted in numerous publications. The data have led to improvements of the

  9. European Unique Hull Identification Number for Inland Navigation

    Directory of Open Access Journals (Sweden)

    Ivica Ružić

    2006-03-01

    Full Text Available To enable efficient management of inland navigation processes,specialized information systems should be developedthrough the application of modern information and communicationtechnology (ICT. For this purpose, individual Europeanwaterway and port authorities have developed their ownlocal information systems and databases. Due to the non-conformityof these databases, their integration at the Europeanlevel is confronted with selious problems (COMPRIS, 2003.One of the major problems is the lack of a common Europeanunique identification number for inland barges. For this reason,in some locally managed databases several different identificationnumbers are attributed to one and the same inlandbarge or certain identification numbers are not available. Thesame problem occurs in the communication between waterwayautholities and between waterway and port authorities. Therefore,a unique identification number for all floating objects onthe European waterways should be introduced. At the momentthere are only two official numbers for vessels. The first, the!MO number, introduced in 1978, is only used by maritimevessels. The second, the OFS number (Official Ship Number,is used only for vessels that have a Rhine patent (issued by theCCNR. The OFS number cannot satisfy all the requirementsof RIS Directive 2005/44/EC and the amendment to Directive82/714/EEC on technical requirements for inland navigationvessels in the enlarged European Union. The fact is that only20% of the ranges of codes are reserved for the non-Rhinecountries. A special Electronic Reporting International group(ER! was appointed to formulate a new system for uniqueidentification of inland vessels and also define a databasemodel for vessel characteristics. The initial suggestion of ERIwas to add one character in front of the OFS number in orderto increase its coding capacity. The intention was to make asfew as possible differences/modifications to the system currentlyused under the regime of

  10. Surface-adaptable all-metal micro-four-point probe with unique configuration

    Science.gov (United States)

    Kim, J. K.; Choi, Y. S.; Lee, D. W.

    2015-07-01

    In this paper, we propose a surface-adaptable all-metal micro-four-point probe (μ4PP) with a unique configuration. The μ4PP consists of four independent metallic sub-cantilevers with sharp Cu tips, and an SU-8 body structure to support the sub-cantilevers. The tip height is approximately 15 μm, and the tips are fabricated by anisotropic wet-etching of silicon followed by Cu electroplating. Each metallic cantilever connected to the SU-8 body structure acts as a flexible spring, so that the conducting tip can make gentle, non-destructive contact with fragile surfaces. To enhance the adhesion between the metallic sub-cantilevers and the SU-8 body, mushroom-shaped Cu structures were fabricated using an under-baked and under-exposed photolithography process. Various μ4PPs were designed and fabricated to verify their diverse range of applications, and preliminary experiments were performed using these fabricated μ4PPs. The resultant flexibility and reliability were experimentally confirmed on several samples, such as a polymer cantilever, a graphene flake, and curved metallic surfaces. We also expect that the proposed μ4PP will be suitable for measuring the anisotropic characteristics of crystal materials or the Hall effect in semiconductors.

  11. Isopalhinine A, a unique pentacyclic Lycopodium alkaloid from Palhinhaea cernua.

    Science.gov (United States)

    Dong, Liao-Bin; Gao, Xiu; Liu, Fei; He, Juan; Wu, Xing-De; Li, Yan; Zhao, Qin-Shi

    2013-07-19

    A new pentacyclic (5/6/6/6/7) Lycopodium alkaloid named isopalhinine A (1), which possesses a sterically congested architecture built with a tricyclo[4.3.1.0(3,7)]decane (isotwistane) moiety and a 1-azabicyclo[4.3.1]decane moiety, and palhinines B (2) and C (3) were isolated from Palhinhaea cernua. The structure and absolute configuration of 1 were elucidated by a combination of NMR spectra, optical rotation calculation, and X-ray diffraction experiment. A possible biogenetic pathway was also proposed.

  12. SESAR: Addressing the need for unique sample identification in the Solid Earth Sciences

    Science.gov (United States)

    Lehnert, K. A.; Goldstein, S. L.; Lenhardt, C.; Vinayagamoorthy, S.

    2004-12-01

    The study of solid earth samples is key to our knowledge of Earth's dynamical systems and evolution. The data generated provide the basis for models and hypotheses in all disciplines of the Geosciences from tectonics to magmatic processes to mantle dynamics to paleoclimate research. Sample-based data are diverse ranging from major and trace element abundances, radiogenic and stable isotope ratios of rocks, minerals, fluid or melt inclusions, to age determinations and descriptions of lithology, texture, mineral or fossil content, stratigraphic context, physical properties. The usefulness of these data is critically dependent on their integration as a coherent data set for each sample. If different data sets for the same sample cannot be combined because the sample cannot be unambiguously recognized, valuable information is lost. The ambiguous naming of samples has been a major problem in the geosciences. Different samples are often given identical names, and there is a tendency for different people analyzing the same sample to rename it in their publications according to local conventions. This situation has generated significant confusion, with samples often losing their "history", making it difficult or impossible to link available data. This has become most evident through the compilation of geochemical data in relational databases such as PetDB, NAVDAT, and GEOROC. While the relational data structure allows linking of disparate data for samples published in different references, linkages cannot be established due to ambiguous sample names. SESAR is a response to this problem of ambiguous naming of samples. SESAR will create a common clearinghouse that provides a centralized registry of sample identifiers, to avoid ambiguity, to systematize sample designation, and ensure that all information associated with a sample would in fact be unique. The project will build a web-based digital registry for solid earth samples that will provide for the first time a way to

  13. The unique experience of adults with multimorbidity: a qualitative study

    Directory of Open Access Journals (Sweden)

    Cynthia Duguay

    2014-05-01

    Full Text Available Background: Findings from several countries indicate that the prevalence of multimorbidity is very high among clients of primary healthcare. A deeper understanding of patients’ experiences from their own perspective can greatly enrich any intervention to help them live as well as possible with multimorbidity. Objective: To describe the fundamental structure of adults’ experience with multimorbidity. Design: A phenomenological study was undertaken to describe the experiences of 11 adults with multimorbidity. These adults participated in two semi-structured interviews, the content of which was rigorously analyzed. Results: At the core of the study participants’ multimorbidity experience are the impression of aging prematurely, difficulties with self-care management, and issues with access to the healthcare system, which contribute to the problem’s complexity. Despite these issues, participants with multimorbidity report attempting to take control of their situation and adjusting to daily living. Conclusions: The description of this experience, through the systemic vision of participants, provides a better understanding of the realities experienced by people with multimorbidity.

  14. New Examples of Torsion-Free Non-unique Product Groups

    OpenAIRE

    Carter, William

    2013-01-01

    We give an infinite family of torsion-free groups that do not satisfy the unique product property. For these examples, we also show that each group contains arbitrarily large sets whose square has no uniquely represented element.

  15. Why are predictions of general relativity theory for gravitational effects non-unique?

    International Nuclear Information System (INIS)

    Loskutov, Yu.M.

    1990-01-01

    Reasons of non-uniqueness of predictions of the general relativity theory (GRT) for gravitational effects are analyzed in detail. To authors' opinion, the absence of comparison mechanism of curved and plane metrics is the reason of non-uniqueness

  16. The unique features of glycolytic pathways in Archaea.

    Science.gov (United States)

    Verhees, Corné H; Kengen, Servé W M; Tuininga, Judith E; Schut, Gerrit J; Adams, Michael W W; De Vos, Willem M; Van Der Oost, John

    2003-10-15

    An early divergence in evolution has resulted in two prokaryotic domains, the Bacteria and the Archaea. Whereas the central metabolic routes of bacteria and eukaryotes are generally well-conserved, variant pathways have developed in Archaea involving several novel enzymes with a distinct control. A spectacular example of convergent evolution concerns the glucose-degrading pathways of saccharolytic archaea. The identification, characterization and comparison of the glycolytic enzymes of a variety of phylogenetic lineages have revealed a mosaic of canonical and novel enzymes in the archaeal variants of the Embden-Meyerhof and the Entner-Doudoroff pathways. By means of integrating results from biochemical and genetic studies with recently obtained comparative and functional genomics data, the structure and function of the archaeal glycolytic routes, the participating enzymes and their regulation are re-evaluated.

  17. The Recovery College: A unique service approach and qualitative evaluation.

    Science.gov (United States)

    Newman-Taylor, Katherine; Stone, Nicola; Valentine, Paul; Hooks, Zoe; Sault, Katherine

    2016-06-01

    This study examined the impact of a Recovery College, an educational service model focusing specifically on health care to engage people's hope, agency, and opportunities for recovery. For the purpose of the study, a qualitative approach was used given the absence of research in this area. Eleven people completed semistructured interviews conducted by an independent researcher. Verbatim transcripts were analyzed using thematic analysis. The analyses yielded themes emphasizing the impact of the organizational structure of the college. Coproduction of service delivery was contrasted with traditional provision and identified as fundamental to personal and professional changes made. Recovery College participants described clear gains. These findings are discussed in relation to the recovery literature and highlight the need for routine coproduction of services to facilitate recovery from the often devastating impact of mental ill-health. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  18. Cognitive Measures of Adolescent Depression: Unique or Unitary Constructs?

    Science.gov (United States)

    Ginsburg, Golda S.; Silva, Susan G.; Jacobs, Rachel H.; Tonev, Simon; Hoyle, Rick H.; Kingery, Julie Newman; Reinecke, Mark A.; Curry, John F.; March, John S.

    2009-01-01

    The factor structure of several self-report questionnaires assessing depression-relevant cognitions frequently employed in clinical research was examined in a sample of 390 adolescents (M age =14.54; 216 girls; 74% Caucasian) with current major depressive disorder enrolled in the Treatment of Adolescents with Depression Study. A four-factor solution resulted, accounting for 65% of the total variance. The factors were labeled (a) Cognitive Distortions and Maladaptive Beliefs, (b) Cognitive Avoidance, (c) Positive Outlook, and (d) Solution-Focused Thinking. Internal consistencies for the factor-based composite scores were .83, .85, .84, and .82, respectively. Girls endorsed more negative cognitions than boys on three of the four factors. Maladaptive cognitions were positively related to severity of depression and predicted treatment response. Taken together, findings indicated that there are four distinct domains of cognitions that are present among adolescents with depression that are tapped by several widely used self-report measures of cognitions. PMID:20183663

  19. Panamanian frog species host unique skin bacterial communities

    Directory of Open Access Journals (Sweden)

    Lisa K. Belden

    2015-10-01

    Full Text Available Vertebrates, including amphibians, host diverse symbiotic microbes that contribute to host disease resistance. Globally, and especially in montane tropical systems, many amphibian species are threatened by a chytrid fungus, Batrachochytrium dendrobatidis (Bd, that causes a lethal skin disease. Bd therefore may be a strong selective agent on the diversity and function of the microbial communities inhabiting amphibian skin. In Panamá, amphibian population declines and the spread of Bd have been tracked. In 2012, we completed a field survey in Panamá to examine frog skin microbiota in the context of Bd infection. We focused on three frog species and collected two skin swabs per frog from a total of 136 frogs across four sites that varied from west to east in the time since Bd arrival. One swab was used to assess bacterial community structure using 16S rRNA amplicon sequencing and to determine Bd infection status, and one was used to assess metabolite diversity, as the bacterial production of anti-fungal metabolites is an important disease resistance function. The skin microbiota of the three Panamanian frog species differed in OTU (operational taxonomic unit, ~bacterial species community composition and metabolite profiles, although the pattern was less strong for the metabolites. Comparisons between frog skin bacterial communities from Panamá and the US suggest broad similarities at the phylum level, but key differences at lower taxonomic levels. In our field survey in Panamá, across all four sites, only 35 individuals (~26% were Bd infected. There was no clustering of OTUs or metabolite profiles based on Bd infection status and no clear pattern of west-east changes in OTUs or metabolite profiles across the four sites. Overall, our field survey data suggest that different bacterial communities might be producing broadly similar sets of metabolites across frog hosts and sites. Community structure and function may not be as tightly coupled in

  20. Comparing Unique Title Coverage of Web of Science and Scopus in Earth and Atmospheric Sciences

    Science.gov (United States)

    Barnett, Philip; Lascar, Claudia

    2012-01-01

    The current journal titles in earth and atmospheric sciences, that are unique to each of two databases, Web of Science and Scopus, were identified using different methods. Comparing by subject category shows that Scopus has hundreds of unique titles, and Web of Science just 16. The titles unique to each database have low SCImago Journal Rank…