WorldWideScience

Sample records for hybrid-ii type structures

  1. On the internal structures of inductive types

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The paper investigates the internal structures of hereditary inductive types in logical type theory. By defining a bisimulation equality on the inhabitants of each hereditary inductive type, one is able to show that the inhabitants of a hereditary inductive type satisfy the basic properties of sets. A hereditary inductive type can therefore be conceived as a universe of sets.

  2. Types, structures and theories in NKI

    Institute of Scientific and Technical Information of China (English)

    Xiaoru ZHANG; Zaiyue ZHANG; Yuefei SUI

    2008-01-01

    The National Knowledge,Infrastructure (NKI)is a multi-domain knowledge base. The classical type the-ory is no longer appropriate to describe every kind of object in multi-domains, such as artifacts, natural or micro objects. Three different kinds of type theories are defined: the classical, atomic and pseudo type theories; in the classical type theory, two new type constructors are defined: setm and ∨, to describe the types of sets of all the elements of the types and unions of two sets of different types, respectively. The structures and categories in the type theory are defined, and the sub-structures and homo-morphic structures are used to describe the part-of rela-tions that give the algebraic specifications for the natural objects and the part-of relations between the natural objects, micro objects and artifacts.

  3. Catalyst system of the structured type

    NARCIS (Netherlands)

    Jansen, J.C.; Legein, C.H.; Calis, H.P.A.; Van Bekkum, H.; Gerritsen, A.W.; Van den Bleek, M.

    1994-01-01

    The invention relates to a catalyst system of the structured type, in which a structured support is covered with a layer of molecular sieve crystals and/or modifications thereof. These crystals have substantially the same orientation relative to the support surface. The invention further relates to

  4. Interference enhanced thermoelectricity in quinoid type structures.

    Science.gov (United States)

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

    2015-02-28

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

  5. Structures, Mixed Types - Oil & Gas Locations

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — An Oil and Gas Location is a DEP primary facility type related to the Oil & Gas Program. The sub-facility types related to Oil and Gas that are included in this...

  6. Structures, Mixed Types - Residual Waste Operations

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — A Residual Waste Operation is a DEP primary facility type related to the Waste Management Residual Waste Program. Residual waste is waste generated at an industrial,...

  7. Types and Functions of Coastal Structures

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  8. Structure sensitive properties of KTP-type crystals

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Adding various dopants during the growth of the parent KTiOPO4 (KTP) crystal has given rise to an extensive series of KTP-type crystals. The doped KTP or KTP-type crystals often have very subtle structural variations from pure KTP crystals. As a result of these structural changes the KTP-type crystals often exhibit different physical properties, which may be referred to as structure sensitive properties. It is possible to fine-tune the nonlinear optical properties of KTP crystals through doping. This results in a broad range of applications for KTP-type crystals.

  9. Stochastic Fatigue Analysis of Jacket Type Offshore Structures

    DEFF Research Database (Denmark)

    Sigurdsson, Gudfinnur

    In this paper, a stochastic reliability assessment for jacket type offshore structures subjected to wave loads in deep water environments is outlined. In the reliability assessment, structural and loading uncertainties are taken into account by means of some stochastic variables. To estimate...... statistical measures of structural stress variations the modal spectral analysis method is applied....

  10. Fine structures of type III radio bursts observed by LOFAR

    Science.gov (United States)

    Magdalenic, Jasmina; Marque, Christophe; Fallows, Richard; Mann, Gottfried; Vocks, Christian

    2017-04-01

    On August 25, 2014, NOAA AR 2146 produced the M2.0 class flare (peaked at 15:11 UT). The flare was associated with a coronal dimming, a EUV wave, a halo CME and a radio event observed by LOFAR (the LOw-Frequency Array). The radio event consisted of a type II, type III and type IV radio emissions. In this study, we focus on LOFAR observations of the type III bursts, generally considered to be radio signatures of fast electron beams propagating along open or quasi open field lines. The group of type III bursts was, as usually, observed during the impulsive phase of the flare. At first hand, type III bursts show no peculiarity, but the high frequency/time resolution LOFAR observations reveal that only few of these type III bursts have a smooth emission profile. The majority of bursts is strongly fragmented. Some show a structuring similar to type IIIb bursts, but on a smaller frequency scale, and others show a non-organized patchy structure which gives indication on the possibly related turbulence processes. Although fine structures of type III bursts were already reported, the wealth of fine structures, and the fragmentation of the radio emission observed in this August 25 event is unprecedented. We show that these LOFAR observations bring completely new insight and pose a new challenge for the physics of the acceleration of electron beams and associated emission processes.

  11. Note on Structure Parameters of Wurtzite Type Compounds

    OpenAIRE

    松原, 武生; "/マツバラ, タケオ"; "Totsuji,Chieko/Matsubara,Takeo"

    1990-01-01

    "Crystal parameters of wurtzite type crystals have been investigated based on the optimized bond orbital model which is known to give the crystal structures of some III-VI compounds as the minimum of bonding energy when bond lengths are fixed. In the case of wurtzite type structures, however, it has become clear that the effect of the change in bond lengths has to be taken into account when minimizing bonding energies."

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    to the phase of its input signal. Arguably, the simplest PLL is a type-1 PLL. The type-1 PLLs are characterized by having only one integrator in their control loop and therefore having a high stability margin. However, they suffer from a serious drawback: they cannot achieve zero average steady-state phase-error...... in the presence of frequency drifts. To overcome this drawback of type-1 PLLs, and at the same time, to achieve a fast dynamic response and high filtering capability, a modified PLL structure is proposed in this letter. The proposed PLL has a similar structure to a type-1 PLL, but from the control point of view...... is a type-2 control system. For this reason, it is called the quasi-type-1 PLL (QT1-PLL). The effectiveness of the proposed PLL is confirmed through simulation and experimental results and comparison with standard PLLs....

  13. A New Type Anticorrosion Coating for Ocean Reinforced Concrete Structures

    Institute of Scientific and Technical Information of China (English)

    CHENG Qi; GENG Guisheng; LUO Feng; WU Sanyu; ZHAO Dalin

    2000-01-01

    Corrosion of reinforced concrete structures is a serious problem in ocean engineering. As an orientation of study, anticorrosion coating technique is developed and widely applied, but many problems need to be solved. LSW-2 type anticorrosion coating for maritime reinforced concrete structures is charac lerized by sea water resistance, salt fog resistance, moisture and heat resistance as well as impermeability to chlorions. The new type coating can be applied to wet concrete surface by conventional construction lechnique. It is a breakthrough in solving the above-mentioned problem. The paper mainly introduces the test results, the property indices, coating procedure, construction technique and economic benefit of the coating.

  14. Modulation mechanism and disorder structure in hollandite-type crystals

    Energy Technology Data Exchange (ETDEWEB)

    Wu Xiaojing; Fujiki, Yoshiki; Horiuchi, Shigeo (National Inst. for Research in Inorganic Materials, Ibaraki (Japan)); Ishigame, Mareo (Research Inst. for Scientific Measurements, Tohoku Univ., Sendai (Japan))

    1991-07-01

    The structural modulation in some hollandite-type crystals is explained by a vacancy-displacive modulation model. In this model the large cations located in the tetragonal channels along the c axis deviate from the average position to form a modulation wave. Three types of disorder in the initial phase of the modulation wave have been introduced to interpret apparently different diffraction patterns in hollandite-type crystals. A mathematical analysis as well as optical diffraction give results similar to those experimentally observed. High-resolution transmission electron microscope images have been observed to confirm the discussion further. (orig.).

  15. Photonic crystal type structure in bivalve ligament of Pinctada maxima

    Institute of Scientific and Technical Information of China (English)

    ZHANG GangSheng

    2007-01-01

    The dry ligament of Pinctada maxima normally appears black; however, it can exhibit striking blue structural colors after being wetted by water. The field-mission SEM investigation shows that the ligament is made of lamellae, which, about 35 μm thick, are made of proteins and aragonite fibers of about 78 nm in diameter. In each single lamella, the fibers are highly aligned characterized by a 2D photonic crystal type structure. According to measured reflective spectra and theoretical simulations, the dry and wet ligaments possess photonic stop band at ultraviolet and blue wavelengths, respectively, which are responsible for structural colorations of ligament.

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  17. Structure Stability of Ⅰ-Type Carbon Nanotube Junctions

    Institute of Scientific and Technical Information of China (English)

    夏丹; 袁喆; 李家明

    2002-01-01

    Carbon nanotubes with junctions may play an important role in future ‘nanoelectronics' and future ‘nano devices'.In particular, junctions constructed with metal and semiconducting nanotubes have potential applications. Basedon the orthogonal tight-binding molecular dynamics method, we present our study of the structure stability ofI-type carbon nanotube junctions.

  18. Three-dimensional structure of the wild-type RHDV

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The three-dimensional (3D) structure of the wild-type rabbit hemorrhagic disease virus (RHDV) has been determined to a resolution of 3.2 nm by electron cryomicroscopy and computer image reconstruction techniques. The 3D density map exhibits characteristic structural features of a calicivirus: a T=3 icosahedral capsid with 90 arch-like capsomeres at the icosahedral and local 2-fold axes and 32 large surface hollows at the icosahedral 5- and 3-fold axes. This result confirms that the RHDV isolated in China is a member of the Caliciviridae family. A rather continuous capsid shell was found without channels. However, our RHDV structure also reveals some distinct structural charac-teristics not observed in other caliciviruses, including inter-connected capsomeres and the lack of protuberance on the base of each of the surface hollows. Two types of particles were identified with similar outer capsid structure but dif-ferent density distributions inside the capsid shells, which could not be distinguished by conventional negative staining electron microscopy. As the genomic and subgenomic RNAs are both packaged into particles for RHDV, we suggest that the two types of particles identified correspond to those con-taining either the genomic or subgenomic RNAs, respec-tively.

  19. Extended, regular HI structures around early-type galaxies

    CERN Document Server

    Oosterloo, T; Sadler, E M; Van der Hulst, J M; Serra, P

    2007-01-01

    We discuss the morphology and kinematics of the HI of a sample of 30 southern gas-rich early-type galaxies selected from the HI Parkes All-Sky Survey (HIPASS). This is the largest collection of high-resolution HI data of a homogeneously selected sample. Given the sensitivity of HIPASS, these galaxies represent the most HI-rich early-type galaxies. In two-thirds of the galaxies, we find the HI to be in a large, regular disk- or ring-like structure that in some cases is strongly warped. In the remaining cases we find the HI distributed in irregular tails or clouds offset from the galaxy. The giant, regular HI structures can be up to ~200 kpc in diameter and contain up to 10^10 M_sun of HI. The incidence of irregular HI structures appears to be somewhat higher in elliptical galaxies, but the large, regular structures are observed in both elliptical and S0 galaxies and are not strictly connected to the presence of a stellar disk. If these two types of galaxies are the result of different formation paths, this is ...

  20. Analysis of the structure of different Tibetan Plateau vortex types

    Science.gov (United States)

    Feng, Xinyuan; Liu, Changhai; Fan, Guangzhou; Zhang, Jie

    2017-06-01

    Knowledge of the structure of the Tibetan Plateau vortex (TPV) is of considerable importance for understanding the generation and development mechanisms of this mesoscale system. However, our understanding of vortex structures and our ability to classify them on a physical basis is limited due to insufficient observations. The highresolution new-generation NCEP-CFSR (Climate Forecast System Reanalysis) dataset is used in the present paper to investigate the general structural features of various types of mature TPV through classification and composite structure analysis. Results indicate that the dynamic and thermodynamic structures show regional and seasonal dependency, as well as being influenced by attributes of translation, associated precipitation, and the South Asian high (SAH). The common precipitating TPV (type I), frequently occurring in the west-east-oriented zonal region between 33° and 36°N, is a notably low-level baroclinic and asymmetric system. It resides within a large-scale confluent zone and preferentially travels eastward, potentially moving out of the plateau. The heavy rain vortex (type II) corresponds to a deep vortex circulation occurring in midsummer. The low-level baroclinic sub-category (type IIa) is associated with a low-level jet and mainly originates in the area 32°-35°N, 86°-94°E, preferentially moving east of 90°E and even away from the plateau; meanwhile, the nearly upright sub-category (type IIb), which has a cold center at low levels and a warm center at mid-upper levels, is a quasi-stationary and quasi-symmetric system favorably occurring west of 92°E. A western-pattern SAH exists in the upper troposphere for these two sub-categories. The springtime dry vortex in the western plateau (type III) is warm and shallow (approximately 100 hPa deep), and zonal circulation dominates the large-scale environmental flows in the middle and upper troposphere. The precipitating vortex in the southern plateau occurring during July

  1. NEW TYPE OF VIBRATION STRUCTURE OF VERTICAL DYNAMIC BALANCING MACHINE

    Institute of Scientific and Technical Information of China (English)

    Li Dinggen; Cao Jiguang; Chen Chuanyao; Wang Junwen

    2004-01-01

    A new type of vibration structure of vertical dynamic balancing machine is designed, which is based on the analysis for swing frame of a traditional vertical dynamic balancing machine. The static unbalance and couple unbalance can be separated effectively by using the new machine with the new swing frame. By building the dynamics model, the advantages of the new structure are discussed in detail. The modal and harmonic response are analyzed by using the ANSYS7.0. By comparing the finite element modal analysis with the experimental modal analysis, the natural frequencies and vibration modes are found out. There are many spring boards in the new swing frame. Their stiffness is different and assort with each other. Furthermore, there are three sensors on the measurement points. Therefore, the new dynamic balancing machine can measure the static unbalance and couple unbalance directly, and the influence between them is faint. The new structure has the function of belt-strain compensation to improve the measurement precision. The practical result indicates that the new vertical dynamic balancing machine is suitable for inertial measurement of flying objects, and can overcome the shortcomings of traditional double-plane vertical dynamic balancing machines. The vertical dynamic balancing machine with the new vibration structure can be widely used in the future applications. The modeling and analysis of the new vibration structure provide theoretic instruction and practical experience for designing new type of vertical dynamic balancing machines. Based on the design principles such as stiffness-matching, frequency-adjacence and strain-compensation and so on, various new type of vibration structures can be designed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-01

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

  4. A Low Cost Structurally Optimized Design for Diverse Filter Types.

    Science.gov (United States)

    Kazmi, Majida; Aziz, Arshad; Akhtar, Pervez; Ikram, Nassar

    2016-01-01

    A wide range of image processing applications deploys two dimensional (2D)-filters for performing diversified tasks such as image enhancement, edge detection, noise suppression, multi scale decomposition and compression etc. All of these tasks require multiple type of 2D-filters simultaneously to acquire the desired results. The resource hungry conventional approach is not a viable option for implementing these computationally intensive 2D-filters especially in a resource constraint environment. Thus it calls for optimized solutions. Mostly the optimization of these filters are based on exploiting structural properties. A common shortcoming of all previously reported optimized approaches is their restricted applicability only for a specific filter type. These narrow scoped solutions completely disregard the versatility attribute of advanced image processing applications and in turn offset their effectiveness while implementing a complete application. This paper presents an efficient framework which exploits the structural properties of 2D-filters for effectually reducing its computational cost along with an added advantage of versatility for supporting diverse filter types. A composite symmetric filter structure is introduced which exploits the identities of quadrant and circular T-symmetries in two distinct filter regions simultaneously. These T-symmetries effectually reduce the number of filter coefficients and consequently its multipliers count. The proposed framework at the same time empowers this composite filter structure with additional capabilities of realizing all of its Ψ-symmetry based subtypes and also its special asymmetric filters case. The two-fold optimized framework thus reduces filter computational cost up to 75% as compared to the conventional approach as well as its versatility attribute not only supports diverse filter types but also offers further cost reduction via resource sharing for sequential implementation of diversified image

  5. Comparative research on three types of coaxial slow wave structures

    Institute of Scientific and Technical Information of China (English)

    Xiao Ren-Zhen; Liu Guo-Zhi; Chen Chang-Hua

    2008-01-01

    This paper studies three types of coaxial slow wave structures(SWSs):(1)with ripples on both the inner and outer conductors;(2)with ripples on the outer conductor and smooth on the inner one;and(3)with ripples on the inner conductor and smooth on the outer one.The frequencies,coupling impedances,time growth rates and beam-wave interaction efficiencies of the three types of coaxial SWSs are obtained by theoretical analysis.Moreover,the relativistic Cerenkov generators(RCGs)with the three types of coaxial SWSs are simulated with a fully electromagnetic particle-in-cell code,and the results verify the theoretical analysis.It is proved that the RCG with double-rippled coaxial SWS has the highest conversion efficiency and the shortest starting time.

  6. The Structure and Function of Type III Secretion Systems.

    Science.gov (United States)

    Notti, Ryan Q; Stebbins, C Erec

    2016-02-01

    Type III secretion systems (T3SSs) afford Gram-negative bacteria an intimate means of altering the biology of their eukaryotic hosts--the direct delivery of effector proteins from the bacterial cytoplasm to that of the eukaryote. This incredible biophysical feat is accomplished by nanosyringe "injectisomes," which form a conduit across the three plasma membranes, peptidoglycan layer, and extracellular space that form a barrier to the direct delivery of proteins from bacterium to host. The focus of this chapter is T3SS function at the structural level; we will summarize the core findings that have shaped our understanding of the structure and function of these systems and highlight recent developments in the field. In turn, we describe the T3SS secretory apparatus, consider its engagement with secretion substrates, and discuss the posttranslational regulation of secretory function. Lastly, we close with a discussion of the future prospects for the interrogation of structure-function relationships in the T3SS.

  7. Structural mechanism of C-type inactivation in K+ channels

    Science.gov (United States)

    Cuello, Luis G.; Jogini, Vishwanath; Cortes, D. Marien; Perozo, Eduardo

    2011-01-01

    Interconversion between conductive and non-conductive forms of the K+ channel selectivity filter underlies a variety of gating events, from flicker transitions (μs) to C-type inactivation (ms-s). Here, we report the crystal structure of the K+ channel KcsA in its Open-Inactivated conformation and investigate the mechanism of C-type inactivation gating at the selectivity filter from channels “trapped” in a series of partially open conformations. Five conformer classes were identified with openings ranging, from 12 Å in closed KcsA (Cα-Cα distances at T112) to 32 Å when fully open. They revealed a remarkable correlation between the degree of gate opening and the conformation and ion occupancy of the selectivity filter. We show that a gradual filter backbone reorientation leads first, to a loss of the S2 ion binding site and a subsequent loss of the S3 binding site, presumably abrogating ion conduction. These structures suggest a molecular basis for C-type inactivation in K+ channels. PMID:20613835

  8. Structural mechanism of C-type inactivation in K(+) channels.

    Science.gov (United States)

    Cuello, Luis G; Jogini, Vishwanath; Cortes, D Marien; Perozo, Eduardo

    2010-07-08

    Interconversion between conductive and non-conductive forms of the K(+) channel selectivity filter underlies a variety of gating events, from flicker transitions (at the microsecond timescale) to C-type inactivation (millisecond to second timescale). Here we report the crystal structure of the Streptomyces lividans K(+) channel KcsA in its open-inactivated conformation and investigate the mechanism of C-type inactivation gating at the selectivity filter from channels 'trapped' in a series of partially open conformations. Five conformer classes were identified with openings ranging from 12 A in closed KcsA (Calpha-Calpha distances at Thr 112) to 32 A when fully open. They revealed a remarkable correlation between the degree of gate opening and the conformation and ion occupancy of the selectivity filter. We show that a gradual filter backbone reorientation leads first to a loss of the S2 ion binding site and a subsequent loss of the S3 binding site, presumably abrogating ion conduction. These structures indicate a molecular basis for C-type inactivation in K(+) channels.

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

    Science.gov (United States)

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

    2006-07-01

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

  10. The Structure of Workaholism and Types of Workaholic

    Directory of Open Access Journals (Sweden)

    Malinowska Diana

    2014-06-01

    Full Text Available The aim of the study presented was to verify empirically a conception of workaholism as a multidimensional syndrome. The study also investigated the notion of ‘functional’ and ‘dysfunctional’ types of workaholic, on the basis of the participants’ cognitive evaluations of their quality of life. The research group comprised Polish managers who had graduated with, or were studying to attain, a Master’s degree in Business Administration. The 137 participants completed a set of questionnaires that were based on five different research tools. Confirmatory factor analysis supported the theory that workaholism has a three-dimensional structure that includes behavioural, cognitive, and affective dimensions. Using cluster analysis, three types of worker were identified, two of which represented types of workaholic with different scores for the dimensions of workaholism and for aspects of quality of life. The research demonstrated that workaholism is a three-dimensional construct. It enabled the integration of different perspectives and also confirmed that dysfunctional and functional types of workaholic exist. Furthermore, this paper provides practical insights about workaholism for practitioners of human resources that can be used in the selection and evaluation of employees.

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

    Science.gov (United States)

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

    2006-06-29

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

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

    Science.gov (United States)

    Tavşan, Cengiz; Sipahi, Serkan

    2017-07-01

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

  14. Cerium intermetallics with TiNiSi-type structure

    Energy Technology Data Exchange (ETDEWEB)

    Janka, Oliver; Niehaus, Oliver; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Chevalier, Bernard [Bordeaux Univ. CNRS (UPR 9048), Pessac (France). Inst. de Chimie de la Matiere Condensee de Bordeaux (ICMCB)

    2016-08-01

    Intermetallic compounds with the equiatomic composition CeTX that crystallize with the orthorhombic TiNiSi-type structure can be synthesized with electron-rich transition metals (T) and X = Zn, Al, Ga, Si, Ge, Sn, As, Sb, and Bi. The present review focusses on the crystal chemistry and chemical bonding of these CeTX phases and on their physical properties, {sup 119}Sn and {sup 121}Sb Moessbauer spectra, high-pressure effects, hydrogenation reactions and the formation of solid solutions in order to elucidate structure-property relationships. This paper is the final one of a series of four reviews on equiatomic intermetallic cerium compounds [Part I: Z. Naturforsch. 2015, 70b, 289; Part II: Z. Naturforsch. 2015, 70b, 695; Part III: Z. Naturforsch. 2016, 71b, 165].

  15. The Importance of Disk Structure in Stalling Type I Migration

    CERN Document Server

    Kretke, Katherine A

    2012-01-01

    As planets form they tidally interact with their natal disks. Though the tidal perturbation induced by Earth and super-Earth mass planets is generally too weak to significantly modify the structure of the disk, the interaction is potentially strong enough to cause the planets to undergo rapid type I migration. This physical process may provide a source of short-period super-Earths, though it may also pose a challenge to the emergence and retention of cores on long-period orbits with sufficient mass to evolve into gas giants. Previous numerical simulations have shown that the type I migration rate sensitively depends upon the circumstellar disk's properties, particularly the temperature and surface density gradients. Here, we derive these structure parameters for 1) a self-consistent viscous-disk model based on a constant \\alpha-prescription, 2) an irradiated disk model that takes into account heating due to the absorption of stellar photons, and 3) a layered-accretion disk model with variable \\alpha-parameter...

  16. Bismuth zinc vanadate, BiZn2VO6 : new crystal structure type and electronic structure.

    OpenAIRE

    Nunes, Sayonara Eliziario; Wang, Chun-Hai; So, Karwei; Evans, John S. O.; Evans, Ivana Radosavljevic

    2015-01-01

    We report a combined experimental and computational study of the crystal structure and electronic properties of bismuth zinc vanadate, BiZn2VO6, known for its visible light photocatalytic activity. The crystal structure has been solved from laboratory powder X-ray diffraction data using the repeated minimisations from random starting values method. BiZn2VO6 adopts a new structure type, based on the following building blocks: corner- and edge-sharing ZnO4 tetrahedra, ZnO6 octahedra and VO4 tet...

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

    Directory of Open Access Journals (Sweden)

    Chaolin Yuan

    2017-06-01

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

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

    Science.gov (United States)

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

    2017-03-07

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

  19. Structural Characterization of Novel Pseudomonas aeruginosa Type IV Pilins

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-01-01

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

  20. Structural Analysis of the Pantograph Type IVTM in PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. H.; Koo, G. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The pantograph type IVTM (In.Vessel Transfer Machine) in PGSFR handle fuel assemblies inside the reactor core, which has six kinds of movements and transfers the new and spent core assemblies between the fuel transfer port and the reactor core. In the IVTM, the main tube supports the pantograph arm and the slot in which the movement of the pantograph arm is possible. The gripper mechanism is mounted to the gripper guide structure and the vertical movement of the gripper is possible by using the screw driver shaft. In this study, we performed the primary stress analysis by considering the IVTM 3D configuration. Also, the thermal stress analysis was carried out and the mode characteristics of the structure by the natural frequency analysis were analyzed. The IVTM is supported by the rotating plug, which has the maximum arm length of 1.125 m. When the fuel assemblies are inserted and withdrawn from the reactor core, the refueling design load of 24.5 kN is considered at the gripper. The primary stress analysis is carried out by considering the above design load and a dead weight. Fig. 2 shows the stress intensity distribution due to the refueling design load and the dead weight. As shown in this figure, the maximum stress intensity is 40.6 MPa. Also, from the Fig. 3, we can see that the maximum stress occurs at the rotation pin joint of the pantograph arm link. The maximum dIsplacement is 4mm, which occurs at the lowest end of the pantograph arm. The structural analyses are carried out to evaluate the structural integrity of the IVTM. The primary stress analysis for the refueling design load, the thermal stress analysis and the natural frequency analysis are performed, and the stresses and dIsplacements are evaluated.

  1. Gradient type optimization methods for electronic structure calculations

    CERN Document Server

    Zhang, Xin; Wen, Zaiwen; Zhou, Aihui

    2013-01-01

    The density functional theory (DFT) in electronic structure calculations can be formulated as either a nonlinear eigenvalue or direct minimization problem. The most widely used approach for solving the former is the so-called self-consistent field (SCF) iteration. A common observation is that the convergence of SCF is not clear theoretically while approaches with convergence guarantee for solving the latter are often not competitive to SCF numerically. In this paper, we study gradient type methods for solving the direct minimization problem by constructing new iterations along the gradient on the Stiefel manifold. Global convergence (i.e., convergence to a stationary point from any initial solution) as well as local convergence rate follows from the standard theory for optimization on manifold directly. A major computational advantage is that the computation of linear eigenvalue problems is no longer needed. The main costs of our approaches arise from the assembling of the total energy functional and its grad...

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

    Science.gov (United States)

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

    1988-01-01

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

  3. Type of structure of men body engaged in baseball

    Directory of Open Access Journals (Sweden)

    Jagiello Wladyslaw.

    2012-11-01

    Full Text Available An attempt to define the features of structure of sportsmen body - members of collapsible command of Poland on baseball is in-process undertaken (n=20. Age of sportsmen was in a range 18-25 years, and training experience - 7-14 years. Five coefficients (Rohrera, Queteleta II, Manouvrier, growing-gravimetric, pelvic-humeral, and also general surface of body, are certain. Specific gravity of body is expected on the basis of measurings dermic-fatty folds by the use of prognostic equalization of Piechaczka. General fat in a percentage ratio to mass of body is expected on the formula of Brozka i Keys. 20 indexes are in general complication certain. On the basis of their setting of norms the type of structure of body of examinee is set. A comparative group was made by the students of the Warsaw polytechnic institute. The members of masculine collapsible command of Poland differ on baseball, foremost, by the high indexes of diameter of forearm, widths of elbow, surface and mass of body, diameter of shin.

  4. ``N'' structure for type-II superlattice photodetectors

    Science.gov (United States)

    Salihoglu, Omer; Muti, Abdullah; Kutluer, Kutlu; Tansel, Tunay; Turan, Rasit; Ergun, Yuksel; Aydinli, Atilla

    2012-08-01

    In the quest to raise the operating temperature and improve the detectivity of type II superlattice (T2SL) photodetectors, we introduce a design approach that we call the "N structure." N structure aims to improve absorption by manipulating electron and hole wavefunctions that are spatially separated in T2SLs, increasing the absorption while decreasing the dark current. In order to engineer the wavefunctions, we introduce a thin AlSb layer between InAs and GaSb layers in the growth direction which also acts as a unipolar electron barrier. Unlike the symmetrical insertion of AlSb into GaSb layers, N design aims to exploit the shifting of the electron and hole wavefunctions under reverse bias. With cutoff wavelength of 4.3 μm at 77 K, temperature dependent dark current and detectivity measurements show that the dark current density is 3.6 × 10-9 A/cm2, under zero bias. Photodetector reaches background limited infrared photodetection (BLIP) condition at 125 K with the BLIP detectivity (D*BLIP) of 2.6 × 1010 Jones under 300 K background and -0.3 V bias voltage.

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

    Energy Technology Data Exchange (ETDEWEB)

    Danckaert, Thomas

    2010-11-15

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

  6. Galaxy clusters, type Ia supernovae and the fine structure constant

    CERN Document Server

    Holanda, R F L; Colaço, L R; Alcaniz, J S; Landau, S J

    2016-01-01

    As is well known, measurements of the Sunyaev-Zeldovich effect can be combined with observations of the X-ray surface brightness of galaxy clusters to estimate the angular diameter distance to these structures. In this paper, we show that this technique depends on the fine structure constant, $\\alpha$. Therefore, if $\\alpha$ is a time-dependent quantity, e.g., $\\alpha=\\alpha_0 \\phi(z)$, where $\\phi$ is a function of redshift, we argue that current data do not provide the real angular diameter distance, $D_{\\rm{A}}(z)$, to the cluster but instead $D_A^{data}(z) = \\phi(z)^2 D_{\\rm{A}}(z)$. We use this result to derive constraints on a possible variation of $\\alpha$ for a class of dilaton runaway models considering a sample of 25 measurements of $D_A^{data}(z)$ in redshift range $0.023 < z < 0.784$ and estimates of $D_{\\rm{A}}(z)$ from current type Ia supernovae observations. We find no significant indication of variation of $\\alpha$ with the present data.

  7. Structural health monitoring of PC structures with novel types of distributed sensors

    Science.gov (United States)

    Yang, Caiqian; Wu, Zhishen; Zhang, Yufeng

    2010-04-01

    In this paper, the structural health monitoring of a pre-stressed concrete (PC) structure based on two types of distributed sensing techniques is addressed. The sensing elements are Brillouin scattering-based fiber optic sensors (FOSs) and HCFRP (hybrid carbon fiber reinforced polymer) sensors composed of three types of carbon tows. Both types of sensors are characterized by a broad-based and distributed sensing function. The HCFRP sensors are bonded on PC tendon, steel reinforcing bar, and embedded in tensile and compressive concrete sides with epoxy resins and putties. The FOSs are embedded in the tensile and compressive concrete sides where the HCFRP sensors are embedded as well. The distributed sensors are arranged to detect and monitor the initiation and propagation of cracks, yielding of steel reinforcements and corrosion of PC tendons. The experimental investigations demonstrate that the initiation and location of cracks, yielding of steel reinforcements, corrosion of PC tendons and structural health of PC structures can be effectively detected and monitored with such kinds of distributed sensing systems.

  8. Structural basis of RND-type multidrug exporters.

    Science.gov (United States)

    Yamaguchi, Akihito; Nakashima, Ryosuke; Sakurai, Keisuke

    2015-01-01

    Bacterial multidrug exporters are intrinsic membrane transporters that act as cellular self-defense mechanism. The most notable characteristics of multidrug exporters is that they export a wide range of drugs and toxic compounds. The overexpression of these exporters causes multidrug resistance. Multidrug-resistant pathogens have become a serious problem in modern chemotherapy. Over the past decade, investigations into the structure of bacterial multidrug exporters have revealed the multidrug recognition and export mechanisms. In this review, we primarily discuss RND-type multidrug exporters particularly AcrAB-TolC, major drug exporter in Gram-negative bacteria. RND-type drug exporters are tripartite complexes comprising a cell membrane transporter, an outer membrane channel and an adaptor protein. Cell membrane transporters and outer membrane channels are homo-trimers; however, there is no consensus on the number of adaptor proteins in these tripartite complexes. The three monomers of a cell membrane transporter have varying conformations (access, binding, and extrusion) during transport. Drugs are exported following an ordered conformational change in these three monomers, through a functional rotation mechanism coupled with the proton relay cycle in ion pairs, which is driven by proton translocation. Multidrug recognition is based on a multisite drug-binding mechanism, in which two voluminous multidrug-binding pockets in cell membrane exporters recognize a wide range of substrates as a result of permutations at numerous binding sites that are specific for the partial structures of substrate molecules. The voluminous multidrug-binding pocket may have numerous binding sites even for a single substrate, suggesting that substrates may move between binding sites during transport, an idea named as multisite-drug-oscillation hypothesis. This hypothesis is consistent with the apparently broad substrate specificity of cell membrane exporters and their highly efficient

  9. Structural trends in off stoichiometric chalcopyrite type compound semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Stephan, Christiane

    2011-03-15

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

  10. Mass Structure of Axial Vector Types of Leptons and Fields

    CERN Document Server

    Sharafiddinov, Rasulkhozha S

    2011-01-01

    A classification of currents with respect to C-operation admits the existence of C-noninvariant types of Dirac fermions. Among them one can meet an electroweakly charged C-antisymmetrical leptons, the mass of which includes the electric and weak components responsible for the existence of their anapole charge, charge radius and electric dipole moment. Such connections can constitute the paraleptons of axial-vector currents, for example, at the interactions with field of spinless nuclei of true neutrality. We derive the united equations which relate the structural parts of mass to anapole, charge radius and electric dipole of any truly neutral lepton in the framework of flavour symmetry. Thereby, they establish the C-odd nature of leptons and fields at the level of constancy law of the size implied from the multiplication of a weak mass of C-antisymmetrical lepton by its electric mass. Therefore, all leptons of C-antisymmetricality regardless of the difference in masses of an axial-vector character, have the s...

  11. Relationship between branching density and crystalline structure of A- and B-type maize mutant starches.

    Science.gov (United States)

    Gérard, C; Planchot, V; Colonna, P; Bertoft, E

    2000-06-02

    Amylopectin from two double maize mutant starches of A-crystalline (wxdu) and B-crystalline type (aewx) was subjected successively to hydrolysis involving alpha and beta amylases, which isolated clusters and all branching zones of clusters (BZC). Enzymatic analysis together with ionic and size-exclusion chromatography revealed the structural features of the clusters and BZC and their role in starch crystallization. A-type clusters were larger (dp(n) > 80) and contained more (but shorter) chains than B-type clusters. The BZC of A-type starch was also larger, but with a shorter distance between the branching points than in B-type BZC. A-type clusters had a densely packed structure and B-type a poorly branched structure. Models for the structure of A- and B-type clusters are presented, and a hypothesis for the influence of cluster geometry on crystallization is proposed.

  12. Structure and organization of heteromeric AMPA-type glutamate receptors

    National Research Council Canada - National Science Library

    Herguedas, Beatriz; García-Nafría, Javier; Cais, Ondrej; Fernández-Leiro, Rafael; Krieger, James; Ho, Hinze; Greger, Ingo H

    2016-01-01

    .... This organization is confirmed by cysteine cross-linking in full-length receptors, and it permitted us to determine the structure of an intact GluA2/3 receptor by cryogenic electron microscopy...

  13. Local Linearizability for Concurrent Container-Type Data Structures

    OpenAIRE

    Haas, Andreas; Henzinger, Thomas A.; Holzer, Andreas; Kirsch, Christoph M.; Lippautz, Michael; Payer, Hannes; Sezgin, Ali; Sokolova, Ana; Veith, Helmut

    2016-01-01

    The semantics of concurrent data structures is usually given by a sequential specification and a consistency condition. Linearizability is the most popular consistency condition due to its simplicity and general applicability. Nevertheless, for applications that do not require all guarantees offered by linearizability, recent research has focused on improving performance and scalability of concurrent data structures by relaxing their semantics. In this paper, we present local linearizabi...

  14. Structures of the Mating-Type Loci of Cordyceps takaomontana

    Science.gov (United States)

    Yokoyama, Eiji; Yamagishi, Kenzo; Hara, Akira

    2003-01-01

    Nucleotide sequences of the mating-type loci MAT1-1 and MAT1-2 of Cordyceps takaomontana were determined, which is the first such report for the clavicipitaceous fungi. MAT1-1 contains two mating-type genes, MAT1-1-1 and MAT1-1-2, but MAT1-1-3 could not be found. On the other hand, MAT1-2 has MAT1-2-1. A pseudogene of MAT1-1-1 is located next to MAT1-2. PMID:12902305

  15. The Gd{sub 14}Ag{sub 51} structure type and its relation to some complex amalgam structures

    Energy Technology Data Exchange (ETDEWEB)

    Tambornino, Frank; Sappl, Jonathan; Hoch, Constantin, E-mail: constantin.hoch@cup.uni-muenchen.de

    2015-01-05

    Highlights: • The Gd{sub 14}Ag{sub 51} structure type has been revisited on the basis of single crystal diffraction data. • Symmetry analysis from electron density and TEM shows the space group P6/m to be true. • Gd{sub 14}Ag{sub 51} shows good metallic behaviour. • Structure relations to alkali, alkaline-earth and rare-earth metal amalgams can be established. • Complexity values for the RE{sub 14}Ag{sub 51} structure family were calculated. - Abstract: A plethora of binary and ternary intermetallic compounds has been assigned to the Gd{sub 14}Ag{sub 51} structure type, crystallising in the hexagonal system (space group P6/m, a = 1264.30(18) pm, c = 933.58(11) pm for Gd{sub 14}Ag{sub 51}). Starting in the late 1960s, much work has been invested in the structural elucidation of these crystal structures. However, reliable single crystal data are scarce, and most structure type assignments have been performed merely on the basis of powder data. We have redetermined four representatives of the binary RE{sub 14}Ag{sub 51} structure type (RE = Y, Ce, Gd, Tb) with modern high-precision single crystal X-ray methods. The assignment of the Gd{sub 14}Ag{sub 51} structure type to space group P6/m was additionally verified by careful analysis of high resolution transmission electron micrographs. We emphasise the close relation of the Gd{sub 14}Ag{sub 51} structure type to the structures of some recently described amalgams of similar composition focussing on disorder phenomena and structural complexity. Furthermore, we provide detailed information on synthesis as well as electrical and magnetic properties for Gd{sub 14}Ag{sub 51}, the parent compound of this structure family.

  16. Well-formedness and typing rules for UML Composite Structures

    CERN Document Server

    Dragomir, Iulia

    2010-01-01

    Starting from version 2.0, UML introduced hierarchical composite structures, which are an expressive way of defining complex software architectures, but which have a very loosely defined semantics in the standard. In this paper we propose a set of consistency rules that disambiguate the meaning of UML composite structures. Our primary goal was to have an operational model of composite structures for the OMEGA UML profile, an executable profile dedicated to the formal specification and validation of real-time systems, developed in a past project to which we contributed. However, the rules and principles stated here are applicable to other hierarchical component models based on the same concepts, such as SysML. The presented ruleset is supported by an OCL formalization which is described in this report. This formalization was applied on different complex models for the evaluation and validation of the proposed principles.

  17. A new type of mass structured data duplicate data check

    Directory of Open Access Journals (Sweden)

    Huang Wen Qi

    2016-01-01

    Full Text Available In this study, the data processing method of a large-scale isoface is used to reduce the storage space of internal memory, improve data structure, and achieve predictability. The design of an algorithm mainly includes the following tasks: increasing the operation speed by improving the parallel granular of the GPU, finishing the segmentation of the adaptive tetrahedral octree, calculating the dual points through the quadric error function in four-dimensional space, searching for the minimum edge as well as finishing the data structure of the edge and the design of the octree node, and proposing that the algorithm be constantly performed until all levels of the minimum edge are found. The result of the algorithm design for the large-scale data is that the speed of parallel algorithms improves and the effect becomes more obvious. Research on large-scale data access high-speed ratio and structure improvement have experimental and theoretical reference value.

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

    Science.gov (United States)

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

    1998-08-01

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

  19. Types of structural unemployment in the United Kingdom.

    Science.gov (United States)

    Hart, P E

    1990-01-01

    The author assesses the importance of each classification of "structural unemployment, namely technological, mismatch of skills, geographical mismatch, demographic shifts, institutional rigidities, 'unemployability', and capital-restructuring unemployment." in the United Kingdom. He also reviews recent evidence on regional wage differential adjustments and their impact on the disequilibrium within the British labor market.

  20. Structural group auditing of a UMLS semantic type's extent.

    Science.gov (United States)

    Chen, Yan; Gu, Huanying Helen; Perl, Yehoshua; Geller, James; Halper, Michael

    2009-02-01

    Each UMLS concept is assigned one or more of the semantic types (STs) from the Semantic Network. Due to the size and complexity of the UMLS, errors are unavoidable. We present two auditing methodologies for groups of semantically similar concepts. The straightforward procedure starts with the extent of an ST, which is the group of all concepts assigned this ST. We divide the extent into groups of concepts that have been assigned exactly the same set of STs. An algorithm finds subgroups of suspicious concepts. The human auditor is presented with these subgroups, which purportedly exhibit the same semantics, and thus she will notice different concepts with wrong or missing ST assignments. The dynamic procedure detects concepts which become suspicious in the course of the auditing process. Both procedures are applied to two semantic types. The results are compared with a comprehensive manual audit and show a very high error recall with a much higher precision.

  1. Structures in the fundamental plane of early-type galaxies

    CERN Document Server

    Fraix-Burnet, Didier; Chattopadhyay, Tanuka; Chattopadhyay, Asis Kumar; Davoust, Emmanuel

    2010-01-01

    The fundamental plane of early-type galaxies is a rather tight three-parameter correlation discovered more than twenty years ago. It has resisted a both global and precise physical interpretation despite a consequent number of works, observational, theoretical or using numerical simulations. It appears that its precise properties depend on the population of galaxies in study. Instead of selecting a priori these populations, we propose to objectively construct homologous populations from multivariate analyses. We have undertaken multivariate cluster and cladistic analyses of a sample of 56 low-redshift galaxy clusters containing 699 early-type galaxies, using four parameters: effective radius, velocity dispersion, surface brightness averaged over effective radius, and Mg2 index. All our analyses are consistent with seven groups that define separate regions on the global fundamental plane, not across its thickness. In fact, each group shows its own fundamental plane, which is more loosely defined for less diver...

  2. A Low Cost Structurally Optimized Design for Diverse Filter Types

    OpenAIRE

    Kazmi, Majida; Aziz, Arshad; AKHTAR, Pervez; Ikram, Nassar

    2016-01-01

    A wide range of image processing applications deploys two dimensional (2D)-filters for performing diversified tasks such as image enhancement, edge detection, noise suppression, multi scale decomposition and compression etc. All of these tasks require multiple type of 2D-filters simultaneously to acquire the desired results. The resource hungry conventional approach is not a viable option for implementing these computationally intensive 2D-filters especially in a resource constraint environme...

  3. Phase transition between the CaCl2-type and α-PbO2-type structures of germanium dioxide

    Science.gov (United States)

    Ono, Shigeaki; Tsuchiya, Taku; Hirose, Kei; Ohishi, Yasuo

    2003-10-01

    Observations of the phase transition between the CaCl2-type (Pnnm) and α-PbO2-type (Pbcn) structures of germanium dioxide (GeO2) were carried out using quench and in situ x-ray diffraction methods in a laser-heated diamond anvil cell (LHDAC). First-principle theoretical simulations were also performed to complement the experimental results. The experiments showed that the transition had a positive dP/dT dependence. The phase boundary between the CaCl2-type and α-PbO2-type structures in the temperature range 1500 2400 K was determined to be P (GPa)=(53±3)+(0.011±0.005)(T-1800) (K) based on the equation of state of platinum and the ruby scale. The positive slope of the transition is consistent with the known phase boundary between the CaCl2-type and α-PbO2-type structures of tin dioxide (SnO2) as germanium dioxide analog and theoretical simulation results. However, our results do not agree with the slope of the phase boundary of silica (SiO2), which has been reported to have a negative slope.

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

    NARCIS (Netherlands)

    Bouwma, Jakob

    1972-01-01

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

  5. Improved ultrasonic differentiation model for structural coal types based on neural network

    Institute of Scientific and Technical Information of China (English)

    TIAN Zi-jian; WANG Fu-zhong; LI Tao; BAI Shan-shan

    2009-01-01

    In order to solve the difficulty of detailed recognition of subdivisions of structural coal types, a differentiation model that combines BP neural network with an ultrasonic reflection method is proposed. Structural coal types are recognized based on a suit-able consideration of ultrasonic speed, an ultrasonic attenuation coefficient, characteristics of ultrasonic transmission and other parameters relating to structural coal types. We have focused on a computational model of ultrasonic speed, attenuation coefficient in coal and differentiation algorithm of structural coal types based on a BP neural network. Experiments demonstrate that the model can distinguish structural coal types effectively. It is important for the improved ultrasonic differentiation model to predict coal and gas outbursts.

  6. Structural patterns of land types and optimal allocation of land use in Qinling Mountains

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The case study based on Qinling Mountains in Shaanxi Province of China, in virtue of the information from TM image, classifies the land types and analyzes their spatial and temporal differential law, and puts forward three structural patterns of land types in mountainous areas, namely, spatial, quantitative and qualitative structures of mountainous land types. Furthermore, it has been noticed that the analysis of structural patterns can disclose the heterogeneity and orderliness of combination of land types, which can lay the theoretic foundation for comprehensively recognizing ecological characteristics and succession law of structure and function of land types. After the all-around comparative analysis, an optimal allocation of land use in Qinling Mountains has been put forward according to the principle of sustainable development and landscape ecology, which can lay the scientific foundation in practice for the structural adjustment and distribution optimization from the macro level to micro level.

  7. Fine-structure constant constraints on Bekenstein-type models

    CERN Document Server

    Leal, P M M; Ventura, L B

    2014-01-01

    Astrophysical tests of the stability of dimensionless fundamental couplings, such as the fine-structure constant $\\alpha$, are an area of much increased recent activity, following some indications of possible spacetime variations at the few parts per million level. Here we obtain updated constraints on the Bekenstein-Sandvik-Barrow-Magueijo model, which is arguably the simplest model allowing for $\\alpha$ variations. Recent accurate spectroscopic measurements allow us to improve previous constraints by about an order of magnitude. We briefly comment on the dependence of the results on the data sample, as well as on the improvements expected from future facilities.

  8. A Bidirectional “Y” Type OXC Structure Using the Least Optical Switches

    Institute of Scientific and Technical Information of China (English)

    TAO Zhenning; WU Deming; XU Anshi

    2000-01-01

    In this paper, a bidirectional Y type optical cross-connect structure is introduced. It minimizes the number of 2 × 2 optical switches by utilizing the route characteristic of a bidirectional Y type OTN node. The method to satisfy this route request by our OXC is demonstrated. The wavelength utilizing efficiency between our structure and the nonblocking bidirectional Y type OTN node has also compared. The blocking, complexity, loss, loss uniformity and cross-talk characteristics are also demonstrated.

  9. Insight into the flagella type III export revealed by the complex structure of the type III ATPase and its regulator.

    Science.gov (United States)

    Imada, Katsumi; Minamino, Tohru; Uchida, Yumiko; Kinoshita, Miki; Namba, Keiichi

    2016-03-29

    FliI and FliJ form the FliI6FliJ ATPase complex of the bacterial flagellar export apparatus, a member of the type III secretion system. The FliI6FliJ complex is structurally similar to the α3β3γ complex of F1-ATPase. The FliH homodimer binds to FliI to connect the ATPase complex to the flagellar base, but the details are unknown. Here we report the structure of the homodimer of a C-terminal fragment of FliH (FliHC2) in complex with FliI. FliHC2 shows an unusually asymmetric homodimeric structure that markedly resembles the peripheral stalk of the A/V-type ATPases. The FliHC2-FliI hexamer model reveals that the C-terminal domains of the FliI ATPase face the cell membrane in a way similar to the F/A/V-type ATPases. We discuss the mechanism of flagellar ATPase complex formation and a common origin shared by the type III secretion system and the F/A/V-type ATPases.

  10. Large HI structures linked to southern O-type stars

    CERN Document Server

    Martín, M C; Romero, G A

    2008-01-01

    In our search for interstellar bubbles around massive stars we analyze the environs of the O-type stars HD 38666, HD 124979, HD 163758, and HD 171589. The location of the stars, which are placed far from the galactic plane, favors the formation of large wind bubbles. We investigate the distribution of the neutral and ionized gas based on HI, CO, and radio continuum data, and that of the interstellar dust based on far infrared IRIS images. Here we report the discovery of neutral gas cavities and slowly expanding shells associated with the four massive stars. IR and optical counterparts were also detected for some of the stars. We discuss the probability that the features have originated in the action of the stellar winds on the surrounding gas.

  11. Flaring loop parameters estimated from solar decimeter type U-like and type J-like fine structures

    Science.gov (United States)

    Fernandes, Francisco C. R.; Dutra, José Augusto S. S.; Cunha da Silva, Rafael D.; Sawant, Hanumant S.

    2012-06-01

    This work presents the analysis of five fine structures in the solar radio emission, observed between June 2000 and October 2001 by the Brazilian Solar Spectroscope (BSS), in the decimeter frequency band of 950-2500 MHz. Based on their morphological characteristics identified in the dynamic spectra, the fine structures had been classified as type U-like or type J-like bursts. Such emissions are variants of the type III bursts. They support the hypothesis of generation by plasma emission mechanism, from interaction of electron beams accelerated during solar flares, propagating along closed magnetic structures, within the trapped plasma of the solar corona. The spectral and temporal characteristics of the five fine structures had been obtained from the dynamic spectra and the parameters of the agent and the emitting source have been determined, assuming both fundamental and harmonic emissions. The analysis revealed the flux density of the structures is less than 20-80 s.f.u. For assumption of harmonic emission, the interval of values for the source parameters estimated are: the loop size is (0.3-5.1) × 1010 cm; the electron beam velocity is in the range of 0.16-0.53 c; the temperature of coronal loop top is of the order of (0.25-1.55) × 107 K; and the low limit for the magnetic field is of 7-26 G. These results are in agreement with previous determinations reported in the literature.

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

    Directory of Open Access Journals (Sweden)

    Ievgeniia Zapunna

    2015-05-01

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

  13. Structural Analysis of Botulinum Neurotoxin Type G Receptor Binding

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-10-19

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

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

    Science.gov (United States)

    Sakamoto, Yasuhiro

    2017-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Gemma Rutten

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

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

    Science.gov (United States)

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

    2015-01-01

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

  17. [X-ray diffraction study of high hydrostatic pressure on crystalline structure of different type starches].

    Science.gov (United States)

    Liu, Pei-Ling; Shen, Qun; Hu, Xiao-Song; Wu, Ji-Hong

    2012-09-01

    Crystalline changes of different type starches after high hydrostatic pressure treated under 300, 450, 600 MPa were studied by X-ray diffraction. Waxy maize (A type, 100% amylopectin), hylon VII (B type, 30% amylopectin) and tapioca starch (C type, 83% amylopectin) were chosen. The results indicated that for waxy maize starch, annealing effect was observed at 300 MPa, disappearance of crystalline structure happened at 450 MPa and retrogradation at 600 MPa. The results proved that the granule under high hydrostatic pressure processing experiences "three development stages" including annealling effect, disappearance of crystalline structure and recrystalline after granule disintegration.

  18. Structure of the Vibrio cholerae Type IVb Pilus and stability comparison with the Neisseria gonorrhoeae type IVa pilus.

    Science.gov (United States)

    Li, Juliana; Egelman, Edward H; Craig, Lisa

    2012-04-20

    Type IV pili are multifunctional filaments displayed on many bacterial pathogens. Members of the Type IVa pilus subclass are found on a diverse group of human pathogens, whereas Type IVb pili are found almost exclusively on enteric bacteria. The Type IVa and IVb subclasses are distinguished by differences in the pilin subunits, including the fold of the globular domain. To understand the implications of the distinct pilin folds, we compared the stabilities of pilin subunits and pilus filaments for the Type IVa GC pilus from Neisseria gonorrhoeae and the Type IVb toxin-coregulated pilus (TCP) from Vibrio cholerae. We show that while recombinant TCP pilin is more stable than GC pilin, the GC pili are more resistant to proteolysis, heat and chemical denaturation than TCP, remaining intact in 8 M urea. To understand these differences, we determined the TCP structure by electron microscopy and three-dimensional image reconstruction. TCP have an architecture similar to that of GC pili, with subunits arranged in a right-handed 1-start helix and related by an 8.4-Å axial rise and a 96.8° azimuthal rotation. However, the TCP subunits are not as tightly packed as GC pilins, and the distinct Type IVb pilin fold exposes a segment of the α-helical core of TCP. Hydrophobic interactions dominate for both pilus subtypes, but base stacking by aromatic residues conserved among the Type IVa pilins may contribute to GC pilus stability. The extraordinary stability of GC pili may represent an adaptation of the Type IVa pili to harsh environments and the need to retract against external forces. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Crystal structure of Zebrafish interferons I and II reveals conservation of type I interferon structure in vertebrates.

    Science.gov (United States)

    Hamming, Ole Jensen; Lutfalla, Georges; Levraud, Jean-Pierre; Hartmann, Rune

    2011-08-01

    Interferons (IFNs) play a major role in orchestrating the innate immune response toward viruses in vertebrates, and their defining characteristic is their ability to induce an antiviral state in responsive cells. Interferons have been reported in a multitude of species, from bony fish to mammals. However, our current knowledge about the molecular function of fish IFNs as well as their evolutionary relationship to tetrapod IFNs is limited. Here we establish the three-dimensional (3D) structure of zebrafish IFNϕ1 and IFNϕ2 by crystallography. These high-resolution structures offer the first structural insight into fish cytokines. Tetrapods possess two types of IFNs that play an immediate antiviral role: type I IFNs (e.g., alpha interferon [IFN-α] and beta interferon [IFN-β]) and type III IFNs (lambda interferon [IFN-λ]), and each type is characterized by its specific receptor usage. Similarly, two groups of antiviral IFNs with distinct receptors exist in fish, including zebrafish. IFNϕ1 and IFNϕ2 represent group I and group II IFNs, respectively. Nevertheless, both structures reported here reveal a characteristic type I IFN architecture with a straight F helix, as opposed to the remaining class II cytokines, including IFN-λ, where helix F contains a characteristic bend. Phylogenetic trees derived from structure-guided multiple alignments confirmed that both groups of fish IFNs are evolutionarily closer to type I than to type III tetrapod IFNs. Thus, these fish IFNs belong to the type I IFN family. Our results also imply that a dual antiviral IFN system has arisen twice during vertebrate evolution.

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

    Directory of Open Access Journals (Sweden)

    Rafal Pietruszka

    2014-02-01

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

  1. Ultralight X-type lattice sandwich structure(I):Concept,fabrication and experimental characterization

    Institute of Scientific and Technical Information of China (English)

    ZHANG QianCheng; HAN YunJie; CHEN ChangQing; LU TianJian

    2009-01-01

    A new type of ultra-lightweight metallic lattice structure(named as the X-type structure)is reported.This periodic structure was formed by two groups of staggered struts in the traditional pyramid structure,and fabricated by folding expanded metal sheet along rows of offset nodes and then brazing the folded structure(as the core)with top and bottom facesheets to form sandwich panels.The out-ofplane compressive and shear properties of the X-type lattice sandwich structure were investigated experimentally and compared to those of the sandwich having a pyramidal truss core.It is found that the formation of the 2-dimensional staggered nodes can effectively make the X-type structure more resistant to inelastic and plastic buckling under both compression and shear loading than the pyramidal lattice truss.Obtained results show that the compressive and shear peak strengths of the X-type lattice structure are about 30% higher than those of the pyramidal lattice truss having the same relative density.

  2. Structure of corylifuran: a clerodane-type diterpene from Croton corylifolius Lam

    Energy Technology Data Exchange (ETDEWEB)

    Burke, B.A. (Univ. of the West Indies, Kingston, Jamaica); Chan, W.R.; Prince, E.C.; Manchand, P.S.; Eickman, N.; Clardy, J.

    1976-01-01

    The structure and stereochemistry of corylifuran, a clerodane-type diterpene from Croton corylifolius Lam, have been determined as 2 by chemical and spectroscopic data and X-ray crystallographic analysis.

  3. Basic Types and Structural Characteristics of Uplifts: An Overview of Sedimentary Basins in China

    Institute of Scientific and Technical Information of China (English)

    HE Dengfa; LI Desheng; WU Xiaozhi; WEN Zhu

    2009-01-01

    The uplift is a positive structural unit of the crust. It is an important window for continental dynamics owing to its abundant structural phenomena, such as fault, fold, unconformity and denudation of strata. Meanwhile, it is the very place to store important minerals like oil, natural gas, coal and uranium. Giant and large-scale oil and gas fields in China, such as the Daqing Oilfield, Lunnan-Tahe Oilfield, Penglai 19-3 Oilfield, Puguang Gas Field and Jingbian Gas Field, are developed mainly on uplifts. Therefore, it is the main target both for oil and gas exploration and for geological study. The uplift can be either a basement uplift, or one developed only in the sedimentary cover. Extension, compression and wrench or their combined forces may give rise to uplifts. The development process of uplifting, such as formation, development, dwindling and destruction, can be taken as the uplifting cycle. The uplifts on the giant Precambrian cratons are large in scale with less extensive structural deformation. The uplifts on the medium- and small-sized cratons or neo-cratons are formed in various shapes with strong structural deformation and complicated geological structure. Owing to changes in the geodynamic environment, uplift experiences a multi-stage or multi-cycle development process. Its geological structure is characterized in superposition of multi-structural layers. Based on the basement properties, mechanical stratigraphy and development sequence, uplifts can be divided into three basic types--the succession, superposition and destruction ones. The succession type is subdivided into the maintaining type and the lasting type. The superposition type can he subdivided into the composite anticlinal type, the buried-hill draped type, the faulted uplift type and the migration type according to the different scales and superimposed styles of uplifts in different cycles. The destruction type is subdivided into the tilting type and the negative inverted type. The

  4. One-dimensional quantum spin magnetism of the CrVO{sub 4} structure-type

    Energy Technology Data Exchange (ETDEWEB)

    Law, Joseph; Kremer, Reinhard [Max Planck Institute for Solid State Research, D-70569 Stuttgart (Germany)

    2012-07-01

    In recent years we have investigated and characterized many new and interesting 1D quantum spin systems, as of late we have concentrated on compounds that crystallize in the CrVO{sub 4} structure-type. Here we will present new results for materials that adopt this structure-type, ranging from spin-spiral long-range magnetic order and Multiferrocity to two stage spin-Peierls transitions.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-15

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

  6. Selection versus Structure: Explaining Family Type Differences in Contact with Close Kin

    Science.gov (United States)

    De Bruycker, Trees

    2008-01-01

    This article focuses on one aspect of family networks, namely, the frequency of contact with close kin for adults living in different traditional and new family types. Two mechanisms are hypothesized to account for the differences. The first focuses on structural factors such as the number and type of persons in the primary family network,…

  7. Ultralight X-type lattice sandwich structure(I):Concept,fabrication and experimental characterization

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A new type of ultra-lightweight metallic lattice structure (named as the X-type structure) is reported. This periodic structure was formed by two groups of staggered struts in the traditional pyramid strurture, and fabricated by folding expanded metal sheet along rows of offset nodes and then brazing the folded structure (as the core) with top and bottom facesheets to form sandwich panels. The out-of-plane compressive and shear properties of the X-type lattice sandwich structure were investigated experimentally and compared to those of the sandwich having a pyramidal truss core. It is found that the formation of the 2-dimensional staggered nodes can effectively make the X-type structure more resistant to inelastic and plastic buckling under both compression and shear loading than the pyramidal lattice truss. Obtained results show that the compressive and shear peak strengths of the X-type lattice structure are about 30% higher than those of the pyramidal lattice truss having the same relative density.

  8. A Higher Order Analysis of the Factor Structure of the Myers-Briggs Type Indicator.

    Science.gov (United States)

    Johnson, William L.; Mauzey, Edward; Johnson, Annabel M.; Murphy, Stanley D.; Zimmerman, Kurt J.

    2001-01-01

    Examines the higher order structure of Form G of the Myers Briggs Type Indicator. A third order component analysis of a sample (N=926) found two higher order components. This higher order analysis contributes to the research literature pertaining to the generalized structure of the personality measure. (Contains 44 references and 1 table.) (GCP)

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

    Science.gov (United States)

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

    2015-01-01

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

  10. Response of Dome-enclosed Box-type Structure to Underwater Explosion

    Directory of Open Access Journals (Sweden)

    O.R. Nandagopan

    2013-07-01

    Full Text Available In the development of underwater sensor systems, the sensor arrays are configured for different shapes like cylindrical, rectangular and spherical depending on the requirement. The rectangular shaped box–type structure discussed here has both top and bottom ends open. Flanges stiffen the top and bottom ends, and gussets are used to connect the flanges with the structure. In this paper, the box-type structure is subjected to non-contact underwater explosion in a shock tank to study the peak free field pressure on the structure. To simulate the actual conditions, the structure is placed in free flooded area and covered with a dome. The free-field peak pressure on the dome and structure are plotted with time. The measured pressure curves are in agreement with the empirical predictions reported in literature. It is concluded that around 85 per cent of the shock impulse acting on the dome is transmitted to the box-type structure. The dome and box-type structure withstood the explosive load, thereby validating their design.

  11. Response of Dome-enclosed Box-type Structure to Underwater Explosion

    Directory of Open Access Journals (Sweden)

    O. R. Nandagopan

    2013-07-01

    Full Text Available In the development of underwater sensor systems, the sensor arrays are configured for different shapes like cylindrical, rectangular and spherical depending on the requirement. The rectangular shaped box–type structure discussed here has both top and bottom ends open. Flanges stiffen the top and bottom ends, and gussets are used to connect the flanges with the structure. In this paper, the box-type structure is subjected to non-contact underwater explosion in a shock tank to study the peak free field pressure on the structure. To simulate the actual conditions, the structure is placed in free flooded area and covered with a dome. The free-field peak pressure on the dome and structure are plotted with time. The measured pressure curves are in agreement with the empirical predictions reported in literature. It is concluded that around 85 per cent of the shock impulse acting on the dome is transmitted to the box-type structure. The dome and box-type structure withstood the explosive load, thereby validating their design.Defence Science Journal, 2013, 63(4, pp.381-385, DOI:http://dx.doi.org/10.14429/dsj.63.2130

  12. The Structure of Arizaro, Salta, Argentina: A New Simple Type Meteorite Impact Site?

    Science.gov (United States)

    Acevedo, R. D.; Rocca, M.; Alonso, R.; Rabassa, J.; Ponce, J. F.; Klajnik, K.

    2012-09-01

    A possible new impact crater had been found in Puna, Argentina: the structure of Arizaro (24º 55" 45.30” S, 67º 27" 09.64” W), located at 3,650 m.a.s.l. This structure is probably a new young simple-type impact crater on Tertiary-Quaternary sedimentary deposits.

  13. A Higher Order Analysis of the Factor Structure of the Myers-Briggs Type Indicator.

    Science.gov (United States)

    Johnson, William L.; Mauzey, Edward; Johnson, Annabel M.; Murphy, Stanley D.; Zimmerman, Kurt J.

    2001-01-01

    Examines the higher order structure of Form G of the Myers Briggs Type Indicator. A third order component analysis of a sample (N=926) found two higher order components. This higher order analysis contributes to the research literature pertaining to the generalized structure of the personality measure. (Contains 44 references and 1 table.) (GCP)

  14. Variations of Structural Components: Specific Intercultural Differences in Facial Morphology, Skin Type, and Structures

    OpenAIRE

    McKnight, Aisha; Momoh, Adeyiza O.; Bullocks, Jamal M.

    2009-01-01

    Analysis of the differences in facial morphology and skin structure and tone among ethnic groups within the realm of plastic surgery is relevant due to the increasing number of ethnic individuals seeking cosmetic surgery. Previous classifications of ideal facial morphologic characteristics have been revised and challenged over the years to accurately reflect the differences in facial structure that are aesthetically pleasing to individuals of differing ethnic groups. The traditional neoclassi...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-09-15

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

  16. Hybrid Structure of the Type 1 Pilus of Uropathogenic Escherichia coli.

    Science.gov (United States)

    Habenstein, Birgit; Loquet, Antoine; Hwang, Songhwan; Giller, Karin; Vasa, Suresh Kumar; Becker, Stefan; Habeck, Michael; Lange, Adam

    2015-09-28

    Type 1 pili are filamentous protein assemblies on the surface of Gram-negative bacteria that mediate adhesion to host cells during the infection process. The molecular structure of type 1 pili remains elusive on the atomic scale owing to their insolubility and noncrystallinity. Herein we describe an approach for hybrid-structure determination that is based on data from solution-state NMR spectroscopy on the soluble subunit and solid-state NMR spectroscopy and STEM data on the assembled pilus. Our approach is based on iterative modeling driven by structural information extracted from different sources and provides a general tool to access pseudo atomic structures of protein assemblies with complex subunit folds. By using this methodology, we determined the local conformation of the FimA pilus subunit in the context of the assembled type 1 pilus, determined the exact helical pilus architecture, and elucidated the intermolecular interfaces contributing to pilus assembly and stability with atomic detail.

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

    Directory of Open Access Journals (Sweden)

    J Ker

    2010-08-01

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

  18. The Possible Topologic structure Types of Orthopyroxene with Space Group P21ca

    Institute of Scientific and Technical Information of China (English)

    罗谷风; 林承毅; 等

    1990-01-01

    The possible topologic structure types of orthopyroxene with space group P21ca comprise four kinds of tetrahedral chains and four kinds of octahedral sites.all of which are non-equivalent in symmetry,In these structure types,the skew of the octahedral layers has a sequence of ++--,There are sixteen possible combination forms for the rotation type of tetradral chain.Twelve of them violate Thompson 's sparity rule and the remainder constitutes two pairs.In each pair,the two polar forms show a relationship of anti-orientation for their polar a-axes.Thus,there are only two possible different topologic structure types for P21ca-orthopyroxene.The ratios of O-rotated and S-rotated tetrahedral chains for these two structure types are 3:1 and 1:3,respectively,In the view S-rotated tetrahedral chains for these two structure types are 3:1 and 1:3,respectively,In the view of crystallochemical principle,the most likely form is the one with a ratio of 3:1,and its constitutions of two stacks of I-beam,which are non-equivalent both in symmetry and in topology,are and the configurations of the two types of M2 sites are P.P and P.N,respectively,A complementary twinning on(100) would be formed between the anti-oriented structure pairs,and their twin boundary is exactly equivalent to the inversion boundary,Moreover,it is possible that the ordered structure would appear when the atom ratio of Mg:Fe is equal to 3:1 as well as to 1:1。

  19. Effects of Structural Parameters on the Dynamics of a Beam Structure with a Beam-Type Vibration Absorber

    Directory of Open Access Journals (Sweden)

    Mothanna Y. Abd

    2012-01-01

    Full Text Available A beam-type absorber has been known as one of the dynamic vibration absorbers used to suppress excessive vibration of an engineering structure. This paper studies an absorbing beam which is attached through a visco-elastic layer on a primary beam structure. Solutions of the dynamic response are presented at the midspan of the primary and absorbing beams in simply supported edges subjected to a stationary harmonic load. The effect of structural parameters, namely, rigidity ratio, mass ratio, and damping of the layer and the structure as well as the layer stiffness on the response is investigated to reduce the vibration amplitude at the fundamental frequency of the original single primary beam. It is found that this can considerably reduce the amplitude at the corresponding troublesome frequency, but compromised situation should be noted by controlling the structural parameters. The model is also validated with measured data with reasonable agreement.

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

    Directory of Open Access Journals (Sweden)

    Nenadović Aleksandra

    2010-01-01

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

  1. Distinctive structure in dynamic spectra of type V solar radio bursts

    Energy Technology Data Exchange (ETDEWEB)

    Bakunin, L.M.; Markeev, A.K.; Fomichev, V.V.; Chertok, I.M.

    1979-05-01

    Observations of type V solar radio bursts obtained with a 45--90 MHz radio spectrograph at the Institute of Terrestrial Magnetism are discussed. The dynamic spectra of type V events are highly diversified and complex. Categories of bursts are discriminated, depending on the behavior of the radiation at the leading and trailing edges. Various types of fine structure are encountered in the dynamic spectra of many bursts. An analysis is made of type V bursts that distinctly exhibit radio emission at the frequencies of the fundamental and the second harmonic.

  2. Magnetic and structural transitions in crystals with a structure of the NaCl type

    Science.gov (United States)

    Kassan-Ogly, F. A.; Filippov, B. N.

    2009-04-01

    A model of simultaneous magnetic and structural first-order transitions in antiferromagnets with a strong cubic magnetic anisotropy has been constructed on the basis of a synthesis of magnetic modified 6-state and 8-state Potts models and the theoretical model of structural phase transitions in cubic crystals. A revised scheme has been suggested for the derivation of possible magnetic structures in the fcc lattice with allowance for competing interactions between the nearest and next-nearest neighbors. A calculation of the temperature evolution of high-temperature diffuse magnetic scattering of neutrons has been carried out to show that the mechanism of a magnetic transition at the Néel point is caused by the transformation of diffuse magnetic scattering into magnetic Bragg peaks.

  3. An Integrated Structural Strength Analysis Method for Spar Type Floating Wind Turbine

    Institute of Scientific and Technical Information of China (English)

    胡志强; 刘毅; 王晋

    2016-01-01

    An integrated structural strength analysis method for a Spar type floating wind turbine is proposed in this paper, and technical issues related to turbine structure modeling and stress combination are also addressed. The NREL-5MW “Hywind” Spar type wind turbine is adopted as study object. Time-domain dynamic coupled simulations are performed by a fully-coupled aero-hydro-servo-elastic tool, FAST, on the purpose of obtaining the dynamic characteristics of the floating wind turbine, and determining parameters for design load cases of finite element calculation. Then design load cases are identified, and finite element analyses are performed for these design load cases. The structural stresses due to wave-induced loads and wind-induced loads are calculated, and then combined to assess the structural strength of the floating wind turbine. The feasibility of the proposed structural strength analysis method for floating wind turbines is then validated.

  4. Spectroscopic Evidence for an Oxazolone Structure in Anionic b-Type Peptide Fragments

    Science.gov (United States)

    Grzetic, Josipa; Oomens, Jos

    2012-02-01

    Infrared spectra of anionic b-type fragments generated by collision induced dissociation (CID) from deprotonated peptides are reported. Spectra of the b2 fragments of deprotonated AlaAlaAla and AlaTyrAla have been recorded over the 800-1800 cm-1 spectral range by multiple-photon dissociation (MPD) spectroscopy using an FTICR mass spectrometer in combination with the free electron laser FELIX. Structural characterization of the b-type fragments is accomplished by comparison with density functional theory calculated spectra at the B3LYP/6-31++G(d,p) level for different isomeric structures. Although diketopiperazine structures represent the energetically lowest isomers, the IR spectra suggest an oxazolone structure for the b2 fragments of both peptides. Deprotonation is shown to occur on the oxazolone α-carbon, which leads to a conjugated structure in which the negative charge is practically delocalized over the entire oxazolone ring, providing enhanced gas-phase stability.

  5. Life comparative analysis of energy consumption and CO₂ emissions of different building structural frame types.

    Science.gov (United States)

    Kim, Sangyong; Moon, Joon-Ho; Shin, Yoonseok; Kim, Gwang-Hee; Seo, Deok-Seok

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Anggie Angeline

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Sangyong Kim

    2013-01-01

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

  8. Cryo-EM structures of two bovine adenovirus type 3 intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Lingpeng; Huang, Xiaoxing; Li, Xiaomin [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Xiong, Wei [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Luo-jia-shan, Wuhan, Hubei 430072 (China); Sun, Wei; Yang, Chongwen; Zhang, Kai; Wang, Ying [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Liu, Hongrong [College of Physics and Information Science, Hunan Normal University, Changsha, Hunan 410081 (China); Huang, Xiaojun; Ji, Gang; Sun, Fei [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Zheng, Congyi, E-mail: cctcc202@whu.edu.cn [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Luo-jia-shan, Wuhan, Hubei 430072 (China); Zhu, Ping, E-mail: zhup@ibp.ac.cn [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China)

    2014-02-15

    Adenoviruses (Ads) infect hosts from all vertebrate species and have been investigated as vaccine vectors. We report here near-atomic structures of two bovine Ad type 3 (BAd3) intermediates obtained by cryo-electron microscopy. A comparison between the two intermediate structures reveals that the differences are localized in the fivefold vertex region, while their facet structures are identical. The overall facet structure of BAd3 exhibits a similar structure to human Ads; however, BAd3 protein IX has a unique conformation. Mass spectrometry and cryo-electron tomography analyses indicate that one intermediate structure represents the stage during DNA encapsidation, whilst the other intermediate structure represents a later stage. These results also suggest that cleavage of precursor protein VI occurs during, rather than after, the DNA encapsidation process. Overall, our results provide insights into the mechanism of Ad assembly, and allow the first structural comparison between human and nonhuman Ads at backbone level. - Highlights: • First structure of bovine adenovirus type 3. • Some channels are located at the vertex of intermediate during DNA encapsidation. • Protein IX exhibits a unique conformation of trimeric coiled–coiled structure. • Cleavage of precursor protein VI occurs during the DNA encapsidation process.

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

    Directory of Open Access Journals (Sweden)

    Guorui Yao

    2017-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-01

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

  11. Structures and Corresponding Functions of Five Types of Picornaviral 2A Proteins.

    Science.gov (United States)

    Yang, Xiaoyao; Cheng, Anchun; Wang, Mingshu; Jia, Renyong; Sun, Kunfeng; Pan, Kangcheng; Yang, Qiao; Wu, Ying; Zhu, Dekang; Chen, Shun; Liu, Mafeng; Zhao, Xin-Xin; Chen, Xiaoyue

    2017-01-01

    Among the few non-structural proteins encoded by the picornaviral genome, the 2A protein is particularly special, irrespective of structure or function. During the evolution of the Picornaviridae family, the 2A protein has been highly non-conserved. We believe that the 2A protein in this family can be classified into at least five distinct types according to previous studies. These five types are (A) chymotrypsin-like 2A, (B) Parechovirus-like 2A, (C) hepatitis-A-virus-like 2A, (D) Aphthovirus-like 2A, and (E) 2A sequence of the genus Cardiovirus. We carried out a phylogenetic analysis and found that there was almost no homology between each type. Subsequently, we aligned the sequences within each type and found that the functional motifs in each type are highly conserved. These different motifs perform different functions. Therefore, in this review, we introduce the structures and functions of these five types of 2As separately. Based on the structures and functions, we provide suggestions to combat picornaviruses. The complexity and diversity of the 2A protein has caused great difficulties in functional and antiviral research. In this review, researchers can find useful information on the 2A protein and thus conduct improved antiviral research.

  12. Response of Box-Type Structures Under Internal-Blast Loading

    Institute of Scientific and Technical Information of China (English)

    WANG Zhongqi; WU Jianguo; BAI Chunhua; LU Yong

    2006-01-01

    The tests of box-type structures under internal-blast loading are carried out.Then a numerical analysis of the test structures is done using a fully coupled numerical finite element model.The break-up process of the structure is simulated.The failure modes of the simulated structure agree well with the experimental results.The effects of the size of the reinforcing bars and the detailing of connections among the rebars in the concrete on the throw velocity of the fragments are discussed.

  13. Ultralight X-type lattice sandwich structure (Ⅱ): Micromechanics modeling and finite element analysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG QianCheng; CHEN AiPing; CHEN ChangQing; LU TianJian

    2009-01-01

    The methods of homogenization and finite elements are employed to predict the effective elastic con-stants and stress-strain responses of a new type of lattice structure, the X-structure proposed by the authors in a companion paper. It is shown that in most cases the predictions by the equivalent ho-mogenization theory agree well with the experimental and 3-dimensional finite element calculated re-sults. The theoretical and numerical study supports the argument that the X-structure is superior to the pyramid lattice structure in terms of mechanical strength.

  14. Ultralight X-type lattice sandwich structure (Ⅱ):Micromechanics modeling and finite element analysis

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The methods of homogenization and finite elements are employed to predict the effective elastic constants and stress-strain responses of a new type of lattice structure,the X-structure proposed by the authors in a companion paper. It is shown that in most cases the predictions by the equivalent homogenization theory agree well with the experimental and 3-dimensional finite element calculated results. The theoretical and numerical study supports the argument that the X-structure is superior to the pyramid lattice structure in terms of mechanical strength.

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

    Science.gov (United States)

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

    2016-05-19

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

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

    DEFF Research Database (Denmark)

    Taherkhani, Masoomeh; Gregersen, Niels; Willatzen, Morten

    2017-01-01

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

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

    Science.gov (United States)

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

    2011-08-01

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

  18. Comparative modeling of the three-dimensional structure of type II antifreeze protein.

    OpenAIRE

    Sönnichsen, F D; Sykes, B D; Davies, P. L.

    1995-01-01

    Type II antifreeze proteins (AFP), which inhibit the growth of seed ice crystals in the blood of certain fishes (sea raven, herring, and smelt), are the largest known fish AFPs and the only class for which detailed structural information is not yet available. However, a sequence homology has been recognized between these proteins and the carbohydrate recognition domain of C-type lectins. The structure of this domain from rat mannose-binding protein (MBP-A) has been solved by X-ray crystallogr...

  19. Isolation and structure of hematoside-type ganglioside from the starfish Linckia laevigata.

    Science.gov (United States)

    Inagaki, Masanori; Saito, Takeshi; Miyamoto, Tomofumi; Higuchi, Ryuichi

    2009-02-01

    A hematoside-type ganglioside, LLG-1 (1), has been obtained from the polar lipid fraction of the chloroform/methanol extract of the starfish Linckia laevigata. The structure of the ganglioside has been determined on the basis of chemical and spectroscopic evidence as 1-O-[N-glycolyl-alpha-D-neuraminosyl-(2-->3)-beta-D-galactopyranosyl-(1-->4)-beta-D-glucopyranosyl]-ceramide. The ceramide moiety was composed of heterogeneous 2-hydroxy fatty acid and phytosphingosine units. This is the first report on the isolation and structure elucidation of naked hematoside-type ganglioside from echinoderms.

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

    DEFF Research Database (Denmark)

    Julenius, Karin; Mølgaard, Anne; Gupta, Ramneek;

    2004-01-01

    than a nonglycosylated one. The Protein Data Bank was analyzed for structural information, and 12 glycosylated structures were obtained. All positive sites were found in coil or turn regions. A method for predicting the location for mucin-type glycosylation sites was trained using a neural network...... could be predicted from averaged properties together with the fact that glycosylation sites are not precisely conserved indicates that mucin-type glycosylation in most cases is a bulk property and not a very site-specific one. NetOGlyc 3.1 is made available at www.cbs.dtu.dk/services/netoglyc....

  1. Novel Compact Mushroom-Type EBG Structure for Electromagnetic Coupling Reduction of Microstrip Antenna array

    Science.gov (United States)

    Hu, Lizhong; Wang, Guangming; Liang, Jiangang; Zhang, Chenxin

    2015-03-01

    A novel compact electromagnetic bandgap (EBG) structure consisting of two turns complementary spiral resonator (CSR) and conventional mushroom EBG (CM-EBG) structure is introduced to suppress the mutual coupling in antenna arrays for multiple-input and multiple-output (MIMO) applications. Eigenmode calculation is used to investigate the proposed CSR-loaded mushroom-type EBG (MT-EBG), which proved to exhibit bandgap property and a miniaturization of 48.9% is realized compared with the CM-EBG. By inserting the proposed EBG structure between two E-plane coupled microstrip antennas, a mutual coupling reduction of 8.13 dB has been achieved numerically and experimentally. Moreover, the EBG-loaded antenna has better far-field radiation patterns compared with the reference antenna. Thus, this novel EBG structure with advantages of compactness and high decoupling efficiency opens an avenue to new types of antennas with super performances.

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

    Directory of Open Access Journals (Sweden)

    Rafael Antonio Pertuz Belloso

    2013-12-01

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

  3. A Study on Hydroelastic Response of Box-Type Very Large Floating Structures

    Institute of Scientific and Technical Information of China (English)

    王志军; 李润培; 舒志

    2001-01-01

    The application of very large floating structure (VLFS) to the utilization of ocean space and exploitation of ocean resources has become one of the issues of great interest in international ocean engineering field. Owing to the advantage of simplicity in structure and low cost of construction and maintenance, box-type VLFS can be used in the calm water area near the coast as the structure configuration of floating airport. In this paper, a 3D linear hydroelastic theory is used to study the dynamic response of box-type VLFS in sinusoidal regular waves. A beam model and a 3D FEM model are respectively employed to describe the dynamic characteristics of the box-type structure in vacuum. A hydrodynamic model (3D potential theory of flexible body) is applied to investigate the effect of different dry models on the hydroelastic response of box-type structure. Based on the calculation of hydroelastic response in regular waves, the rigid body motion displacement, flexible deflection, and the short term and long term wave induced bending moments are also predicted.

  4. Frobenius type and CV-structures for Donaldson-Thomas theory and a convergence property

    CERN Document Server

    Barbieri, Anna

    2015-01-01

    We rephrase some well-known results in Donaldson-Thomas theory in terms of (formal families of) Frobenius type and CV-structures on a vector bundle in the sense of Hertling. We study these structures in an abstract setting, and prove a convergence result which is relevant to the case of triangulated categories. An application to physical field theory is also briefly discussed.

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

    DEFF Research Database (Denmark)

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

    In far scrape-o layer (SOL), alternating negative and positive burst structures in ion saturation current were detected at the onset of each type-III edge localized mode (ELM) on EAST. Different from the fast streaming phenomenon reported previously, one subsequent positive burst structure appears...... led generated by scrape-off layer current can ultimately trigger the ELM through the coupling with MHD modes inside the separatrix....

  6. Crystal structure and physical properties of Cr oxide with K2NiF4-type structure

    Science.gov (United States)

    Kao, Ting-Hui; Sakurai, Hiroya; Kolodiazhnyi, Taras; Suzuki, Yutaro; Okabe, Momoko; Asaka, Toru; Fukuda, Koichiro; Okubo, Susumu; Ikeda, Shohei; Hara, Shigeo; Sakurai, Takahiro; Ohta, Hitoshi; Yang, Hung-Duen; National Sun-Yet Sen University Team; National InstituteMaterials Science Team; Nagoya Institute of Technology Collaboration; Kobe University Collaboration

    2015-03-01

    Ruddlesden-Popper (RP) type structure materials have been attracted much attention due to their interesting physical properties including high-Tc superconductivity, charge stripe, itinerant ferromagnetism and so on. In this work we are presenting physical properties of some of the K2NiF4 type structure compounds. YSrCrO4 is first synthesized and found to be a hetto-type K2NiF4 structure. The space group of YSrCrO4 is determined to be orthorhombic Pccn by the electron diffraction and the powder X-ray diffraction. YSrCrO4 shows two-dimensional (2D) spin correlations and a canted antiferromagnetic (AF) ordering. Evidence of AF ordering of the Cr oxides is obtained microscopically from ESR. The dielectric measurements suggest existence of in-gap states, while no magneto-dielectric coupling was observed in the above compounds. National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.

  7. Subject reduction in a Curry-style polymorphic type system with a vectorial structure

    CERN Document Server

    Arrighi, Pablo; Valiron, Benoît

    2010-01-01

    The algebraic lambda-calculus [Vau09] and the linear-algebraic lambda-calculus [AD08] extend the lambda-calculus with the possibility of making arbitrary linear combinations of lambda-terms. The two foundational works of [ADC09] and [DCP10] describe type systems for this calculus respectively accounting for scalars and sums. Building on these approaches, we devise a typed algebraic lambda-calculus merging the two approaches while keeping a language featuring local confluence and a weak subject reduction. This gives rise to an original and general type theory where types, in the same way as terms, have a vector space-like structure. The main contribution of this paper is a subject reduction result, a problem renowned to be a delicate matter under the presence of union-like type constructs.

  8. Allomorph distribution and granule structure of lotus rhizome C-type starch during gelatinization.

    Science.gov (United States)

    Cai, Canhui; Cai, Jinwen; Man, Jianmin; Yang, Yang; Wang, Zhifeng; Wei, Cunxu

    2014-01-01

    The allomorph distribution and granule structure of C-type starch from lotus rhizomes were investigated using a combination of techniques during gelatinization. The disruption of crystallinity during gelatinization began from the end distant from the eccentric hilum and then propagated into the center of granule. The periphery of hilum end was finally gelatinized, accompanied by high swelling. The crystallinity changed from C-type to A-type via CA-type during gelatinization, and finally became amorphous structure. The amylose content, crystal degree, helix content, ratio of 1045/1022cm(-1), and peak intensity of crystalline lamellae of gelatinizing starch significantly decreased after 70°C. The amorphous content and ratio of 1022/995cm(-1) increased after 70°C. This study elucidated that B-type allomorph was mainly arranged in the distal region of eccentric hilum, A-type allomorph was mainly located in the periphery of hilum end, and the center of granule was a mixed distribution of A- and B-type allomorphs. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2013-01-01

    Exponential growth in the number of available protein sequences is unmatched by the slower growth in the number of structures. As a result, the development of efficient and fast protein secondary structure prediction methods is essential for the broad comprehension of protein structures. Computational methods that can efficiently determine secondary structure can in turn facilitate protein tertiary structure prediction, since most methods rely initially on secondary structure predictions. Recently, we have developed a fast learning optimized prediction methodology (FLOPRED) for predicting protein secondary structure (S. Saraswathi, et al., [1]). Data are generated by using knowledge-based potentials combined with structure information from the CATH database. A neural network-based extreme learning machine (ELM) and advanced particle swarm optimization (PSO) are used with this data to obtain better and faster convergence to more accurate secondary structure predicted results. A five-fold cross-validated testing accuracy of 83.8 % and a segment overlap (SOV) score of 78.3 % are obtained in this study. Secondary structure predictions and their accuracy are usually presented for three secondary structure elements: α-helix, β-strand and coil but rarely have the results been analyzed with respect to their constituent amino acids. In this paper, we use the results obtained with FLOPRED to provide detailed behaviors for different amino acid types in the secondary structure prediction. We investigate the influence of the composition, physico-chemical properties and position specific occurrence preferences of amino acids within secondary structure elements. In addition, we identify the correlation between these properties and prediction accuracy. The present detailed results suggest several important ways that secondary structure predictions can be improved in the future that might lead to improved protein design and engineering. PMID:23907551

  10. Synthesis, structure, and superconductivity in the new-structure-type compound: SrPt6P2.

    Science.gov (United States)

    Lv, Bing; Jawdat, BenMaan I; Wu, Zheng; Sorolla, Maurice; Gooch, Melissa; Zhao, Kui; Deng, Liangzi; Xue, Yu-Yi; Lorenz, Bernd; Guloy, Arnold M; Chu, Ching-Wu

    2015-02-02

    A metal-rich ternary phosphide, SrPt(6)P(2), with a unique structure type was synthesized at high temperatures. Its crystal structure was determined by single-crystal X-ray diffraction [cubic space group Pa3̅; Z = 4; a = 8.474(2) Å, and V = 608.51(2) Å(3)]. The structure features a unique three-dimensional anionic (Pt(6)P(2))(2-) network of vertex-shared Pt(6)P trigonal prisms. The Sr atoms occupy a 12-coordinate (Pt) cage site and form a cubic close-packed (face-centered-cubic) arrangement, and the P atoms formally occupy tetrahedral interstices. The metallic compound becomes superconducting at 0.6 K, as evidenced by magnetic and resistivity measurements.

  11. THE SLACS SURVEY. VIII. THE RELATION BETWEEN ENVIRONMENT AND INTERNAL STRUCTURE OF EARLY-TYPE GALAXIES

    NARCIS (Netherlands)

    Treu, Tommaso; Gavazzi, Raphael; Gorecki, Alexia; Marshall, Philip J.; Koopmans, Leon V. E.; Bolton, Adam S.; Moustakas, Leonidas A.; Burles, Scott

    2009-01-01

    We study the relation between the internal structure of early-type galaxies and their environment using 70 strong gravitational lenses from the SLACS Survey. The Sloan Digital Sky Survey (SDSS) database is used to determine two measures of overdensity of galaxies around each lens-the projected

  12. Unconventional Hamilton-type variational principles for nonlinear elastodynamics of orthogonal cable-net structures

    Institute of Scientific and Technical Information of China (English)

    LI Wei-hua; LUO En; HUANG Wei-jiang

    2007-01-01

    According to the basic idea of classical yin-yang complementarity and modem dual-complementarity, in a simple and unified new way proposed by Luo, the unconventional Hamilton-type variational principles for geometrically nonlinear elastodynamics of orthogonal cable-net structures are established systematically, which can fully characterize the initial-boundary-value problem of this kind of dynamics. An important integral relation is made, which can be considered as the generalized principle of virtual work for geometrically nonlinear dynamics of orthogonal cable-net structures in mechanics. Based on such relationship, it is possible not only to obtain the principle of virtual work for geometrically nonlinear dynamics of orthogonal cable-net structures, but also to derive systematically the complementary functionals for five-field, four-field, three-field and two-field unconventional Hamilton-type variational principles, and the functional for the unconventional Hamilton-type variational principle in phase space and the potential energy functional for one-field unconventional Hamilton-type variational principle for geometrically nonlinear elastodynamics of orthogonal cable-net structures by the generalized Legendre transformation given in this paper. Furthermore, the intrinsic relationship among various principles can be explained clearly with this approach.

  13. Structure cristalline de type alluaudite KNa5Mn3(MoO46

    Directory of Open Access Journals (Sweden)

    Chahira Bouzidi

    2015-01-01

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

  14. Quaternary Structure and Functional Unit of Energy Coupling Factor (ECF)-type Transporters

    NARCIS (Netherlands)

    Beek, Josy ter; Duurkens, Ria H.; Erkens, Guus B.; Slotboom, Dirk Jan

    2011-01-01

    ATP-binding cassette (ABC) transporters mediate transport of diverse substrates across membranes. We have determined the quaternary structure and functional unit of the recently discovered ECF-type (energy coupling factor) of ABC transporters, which is widespread among prokaryotes. ECF transporters

  15. Bilingual Children's Acquisition of English Verb Morphology: Effects of Language Exposure, Structure Complexity, and Task Type

    Science.gov (United States)

    Paradis, Johanne

    2010-01-01

    This study investigated whether bilingual-monolingual differences would be apparent in school-age children's use and knowledge of English verb morphology and whether differences would be influenced by amount of exposure to English, complexity of the morphological structure, or the type of task given. French-English bilinguals (mean age = 6;10)…

  16. Some Cautionary Notes on the Specification and Interpretation of LISREL-type Structural Equation Models.

    Science.gov (United States)

    Baldwin, Beatrice

    LISREL-type structural equation modeling is a powerful statistical technique that seems appropriate for social science variables which are complex and difficult to measure. The literature on the specification, estimation, and testing of such models is voluminous. The greatest proportion of this literature, however, focuses on the technical aspects…

  17. Structural Equation Modeling of Multitrait-Multimethod Data: Different Models for Different Types of Methods

    Science.gov (United States)

    Eid, Michael; Nussbeck, Fridtjof W.; Geiser, Christian; Cole, David A.; Gollwitzer, Mario; Lischetzke, Tanja

    2008-01-01

    The question as to which structural equation model should be selected when multitrait-multimethod (MTMM) data are analyzed is of interest to many researchers. In the past, attempts to find a well-fitting model have often been data-driven and highly arbitrary. In the present article, the authors argue that the measurement design (type of methods…

  18. A structural and functional perspective of DyP-type peroxidase family.

    Science.gov (United States)

    Yoshida, Toru; Sugano, Yasushi

    2015-05-15

    Dye-decolorizing peroxidase from the basidiomycete Bjerkandera adusta Dec 1 (DyP) is a heme peroxidase. This name reflects its ability to degrade several anthraquinone dyes. The substrate specificity, the amino acid sequence, and the tertiary structure of DyP are different from those of the other heme peroxidase (super)families. Therefore, many proteins showing the similar amino acid sequences to that of DyP are called DyP-type peroxidase which is a new family of heme peroxidase identified in 2007. In fact, all structures of this family show a similar structure fold. However, this family includes many proteins whose amino acid sequence identity to DyP is lower than 15% and/or whose catalytic efficiency (kcat/Km) is a few orders of magnitude less than that of DyP. A protein showing an activity different from peroxidase activity (dechelatase activity) has been also reported. In addition, the precise physiological roles of DyP-type peroxidases are unknown. These facts raise a question of whether calling this family DyP-type peroxidase is suitable. Here, we review the differences and similarities of structure and function among this family and propose the reasonable new classification of DyP-type peroxidase family, that is, class P, I and V. In this contribution, we discuss the adequacy of this family name.

  19. THE SLACS SURVEY. VIII. THE RELATION BETWEEN ENVIRONMENT AND INTERNAL STRUCTURE OF EARLY-TYPE GALAXIES

    NARCIS (Netherlands)

    Treu, Tommaso; Gavazzi, Raphael; Gorecki, Alexia; Marshall, Philip J.; Koopmans, Leon V. E.; Bolton, Adam S.; Moustakas, Leonidas A.; Burles, Scott

    2009-01-01

    We study the relation between the internal structure of early-type galaxies and their environment using 70 strong gravitational lenses from the SLACS Survey. The Sloan Digital Sky Survey (SDSS) database is used to determine two measures of overdensity of galaxies around each lens-the projected numbe

  20. Subunit composition, structure, and distribution of bacterial V-type ATPases

    NARCIS (Netherlands)

    Lolkema, Juke S.; Chaban, Yuriy; Boekema, Egbert J.

    The overall structure of V-ATPase complexes resembles that of F-type ATPases, but the stalk region is different and more complex. Database searches followed by sequence analysis of the five water-soluble stalk region subunits C-G revealed that (i) to date V-ATPases are found in 16 bacterial species,

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

    Science.gov (United States)

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

    2017-07-01

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

  2. THE SLACS SURVEY. VIII. THE RELATION BETWEEN ENVIRONMENT AND INTERNAL STRUCTURE OF EARLY-TYPE GALAXIES

    NARCIS (Netherlands)

    Treu, Tommaso; Gavazzi, Raphael; Gorecki, Alexia; Marshall, Philip J.; Koopmans, Leon V. E.; Bolton, Adam S.; Moustakas, Leonidas A.; Burles, Scott

    2009-01-01

    We study the relation between the internal structure of early-type galaxies and their environment using 70 strong gravitational lenses from the SLACS Survey. The Sloan Digital Sky Survey (SDSS) database is used to determine two measures of overdensity of galaxies around each lens-the projected numbe

  3. Tectonic types of deepwater basins and structural segmentation of the North Atlantic

    Science.gov (United States)

    Pushcharovsky, Yu. M.

    2012-03-01

    Typification of tectonic structures is one of the important lines of tectonic research. Recently, I have published several articles, which are concerned with deepwater oceanic basins. This paper is focused on tectonic typification of deepwater basins of the North Atlantic. They are attributed to three types: perispreading, central thalassogenic, and pericontinental. The first type comprises the Irminger, Iceland, Greenland, and Lofoten basins. The first two basins are associated with the Reykjanes Ridge and the two others, with the Mohns Ridge. The central thalassogenic type is exemplified in the Norwegian Basin, while the pericontinental type in the Rockall Trough. Two systems of basins are distinguished by morphostructural and historical-geological features: the northern system of the Oligocene-Quaternary structures and the southern system of the Paleocene-Quaternary structures. The Greenland-Faroe tectonovolcanic zone serves as their tectonic interface. In the tectonic typology of their deepwater basins, the North Atlantic is closer to the Indian than to other oceans. The present-day configuration of the northern basins is determined by neotectonics. The tectonic movements in the northern system of basins at this stage were more contrasting than in the southern system. This explains the greater depth of the former basins. The spatial position of the deepwater basins belonging to different types determines the tectonic segmentation of the oceanic bottom. The southern, central, and northern latitudinal segments correspond to different geodynamic states of the Earth's interior.

  4. Crystal structure of alluaudite-type Na4Co(MoO43

    Directory of Open Access Journals (Sweden)

    Rawia Nasri

    2014-09-01

    Full Text Available The title compound, tetrasodium cobalt(II tris[molybdate(IV], was prepared by solid-state reactions. The structure is isotypic with Na3In2(AsO43 and Na3In2(PO43. The main structural feature is the presence of infinite chains of edge-sharing X2O10 (X = Co/Na dimers, which are linked by MoO4 tetrahedra, forming a three-dimensional framework enclosing two types of hexagonal tunnels in which Na+ cations reside. In this alluaudite structure, Co and Na atoms are located at the same general site with occupancies of 0.503 (5 and 0.497 (6, respectively. The other three Na and one of the two Mo atoms lie on special positions (site symmetries 2, -1, 2 and 2, respectively. The structure is compared with similar structures and other members of alluaudite family.

  5. Croatian banking sector research: relationship between ownership structure, concentration, owners’ type and bank performance

    Directory of Open Access Journals (Sweden)

    Igor Tomičić

    2012-12-01

    Full Text Available Banks are important financial intermediaries of any national economy, and corporate governance has an important role in banking sector; especially due to processes of the globalization and the internationalization, and also because of the sensitivity of the activities between the interest groups. The objective of this paper is to examine the relationship between ownership structure, concentration, owners’ type and bank performance. The authors made a research of banks' ownership structure using publicly available data. Using statistical tools authors discovered relationships between bank ownership structure and bank performance indicators (average asset, total asset, average equity, profit (loss before taxes, profit (loss after taxes, ROAA, ROAE. Further they discuss the relationships between ownership structure and a number of consequences for the bank performance. The authors discovered significant correlation between bank ownership structure and performance indicators variables that are described in the paper.

  6. Sex in smut fungi: Structure, function and evolution of mating-type complexes.

    Science.gov (United States)

    Bakkeren, Guus; Kämper, Jörg; Schirawski, Jan

    2008-08-01

    Smut fungi are basidiomycete plant pathogens that pose a threat to many important cereal crops. In order to be pathogenic on plants, smut fungal cells of compatible mating-type need to fuse. Fusion and pathogenicity are regulated by two loci, a and b, which harbor conserved genes. The functions of the encoded mating-type complexes have been well-studied in the model fungus Ustilago maydis and will be briefly reviewed here. Sequence comparison of the mating-type loci of different smut and related fungi has revealed that these loci differ substantially in structure. These structural differences point to an evolution from tetrapolar to bipolar mating behavior, which might have occurred several independent times during fungal speciation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-02-27

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

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

    Science.gov (United States)

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

    2017-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Samta Jain

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

  10. First structural evidence of sequestration of mRNA cap structures by type 1 ribosome inactivating protein from Momordica balsamina.

    Science.gov (United States)

    Kushwaha, Gajraj Singh; Yamini, Shavait; Kumar, Mukesh; Sinha, Mau; Kaur, Punit; Sharma, Sujata; Singh, Tej P

    2013-05-01

    This is the first structural evidence of recognition of mRNA cap structures by a ribosome inactivating protein. It is well known that a unique cap structure is formed at the 5' end of mRNA for carrying out various processes including mRNA maturation, translation initiation, and RNA turnover. The binding studies and crystal structure determinations of type 1 ribosome inactivating protein (RIP-1) from Momordica balsamina (MbRIP-1) were carried out with mRNA cap structures including (i) N7-methyl guanine (m7G), (ii) N7-methyl guanosine diphosphate (m7GDP), and (iii) N7-methyl guanosine triphosphate (m7GTP). These compounds showed affinities to MbRIP-1 at nanomolar concentrations. The structure determinations of the complexes of MbRIP-1 with m7G, m7GDP, and m7GTP at 2.65, 1.77, and 1.75 Å resolutions revealed that all the three compounds bound to MbRIP-1 in the substrate binding site at the positions which are slightly shifted towards Glu85 as compared to those of rRNA substrates. In this position, Glu85 forms several hydrogen bonds with guanine moiety while N-7 methyl group forms van der Waals contacts. However, the guanine rings are poorly stacked in these complexes. Thus, the mode of binding by MbRIP-1 to mRNA cap structures is different which results in the inhibition of depurination. Since some viruses are known to exploit the capping property of the host, this action of MbRIP-1 may have implications for the antiviral activity of this protein in vivo. The understanding of the mode of binding of MbRIP-1 to cap structures may also assist in the design of anti-viral agents. Copyright © 2013 Wiley Periodicals, Inc.

  11. From Proteomics to Structural Studies of Cytosolic/Mitochondrial-Type Thioredoxin Systems in Barley Seeds

    DEFF Research Database (Denmark)

    Shahpiri, Azar; Svensson, Birte; Finnie, Christine

    2009-01-01

    for Trx, indicating that Trx plays a key role in several aspects of cell metabolism. In contrast to other organisms, plants contain multiple forms of Trx that are classified based on their primary structures and sub-cellular localization. The reduction of cytosolic and mitochondrial types of Trx...... is dependent on NADPH and catalyzed by NADPH-dependent thioredoxin reductase (NTR). In barley, two isoforms each of Trx and NTR have been identified and investigated using proteomics, gene expression, and structural studies. This review outlines the diverse roles suggested for cytosolic/mitochondrial-type Trx...... systems in cereal seeds and summarizes the current knowledge of the barley system including recent data on function, regulation, interactions, and structure. Directions for future research are discussed....

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

    DEFF Research Database (Denmark)

    Bergenholtz, Henning; Pedersen, Heidi Agerbo

    2015-01-01

    This contribution will not describe the structure in existing dictionaries. Instead, it will focus on the decisions that lexicographers make when they draw up the concept for and carry out the production of one or more new dictionaries, or when they consider making changes in the data presentation...... in an existing dictionary. This part of the lexicographical work is what we call structuring, which encompasses a number of various lexicographical decisions. One of these is choosing the fields that a database should contain. Typically, for some of these field types, it will be easy to distribute data...... dictionaries. However, only by producing monofunctional dictionaries is it possible to avoid the type of information overload, which makes polyfunctional dictionaries close to useless on electronic devices such as tablets and smartphones. In the case of monofunctional dictionaries, lexicographical structuring...

  13. In and out of the cation pumps: P-type ATPase structure revisited

    DEFF Research Database (Denmark)

    Bublitz, Maike; Poulsen, Hanne; Morth, Jens Preben

    2010-01-01

    Active transport across membranes is a crucial requirement for life. P-type ATPases build up electrochemical gradients at the expense of ATP by forming and splitting a covalent phosphoenzyme intermediate, coupled to conformational changes in the transmembrane section where the ions are translocated....... The marked increment during the last three years in the number of crystal structures of P-type ATPases has greatly improved our understanding of the similarities and differences of pumps with different ion specificities, since the structures of the Ca2+-ATPase, the Na+,K+-ATPase and the H+-ATPase can now...... be compared directly. Mechanisms for ion gating, charge neutralization and backflow prevention are starting to emerge from comparative structural analysis; and in combination with functional studies of mutated pumps this provides a framework for speculating on how the ions are bound and released as well...

  14. Typhoidal Salmonellae: Use of Multi-Locus Sequence Typing to Determine Population Structure.

    Science.gov (United States)

    Sharma, Priyanka; Dahiya, Sushila; Balaji, Veeraraghavan; Kanga, Anil; Panda, Preetilata; Das, Rashna; Dhanraju, Anbumani; Mendiratta, Deepak Kumar; Sood, Seema; Das, Bimal Kumar; Kapil, Arti

    2016-01-01

    Enteric fever is an invasive infection predominantly caused by Salmonella enterica serovars Typhi and Paratyphi A. The pathogens have evolved from other nontyphoidal salmonellaeto become invasive and host restricted. Emergence of antimicrobial resistance in typhoidal salmonellae in some countries is a major therapeutic concern as the travelers returning from endemic countries carry resistant strains to non endemic areas. In order to understand the epidemiology and to design disease control strategies molecular typing of the pathogen is very important. We performed Multilocus Sequence Typing (MLST) of 251 S. Typhi and 18 S. Paratyphi strains isolated from enteric fever patients from seven centers across India during 2010-2013to determine the population structure and prevalence of MLST sequence types in India. MLST analysis revealed the presence of five sequence types (STs) of typhoidal salmonellae in India namely ST1, ST2 and ST3 for S. Typhi and ST85 and ST129 for S. Paratyphi A.S. Typhi strains showed monophyletic lineage and clustered in to 3 Sequence Types-ST1, ST2 and ST3 and S. Paratyphi A isolates segregated in two sequence types ST85 and ST129 respectively. No association was found between antimicrobial susceptibility and sequence types. This study found ST1 as the most prevalent sequence type of S. Typhi in India followed by ST2, which is in concordance with previous studies and MLST database. In addition a rare sequence type ST3 has been found which is reported for the first time from the Indian subcontinent. Amongst S. Paratyphi A, the most common sequence type is ST129 as also reported from other parts of world. This distribution and prevalence suggest the common spread of the sequence types across the globe and these findings can help in understanding the disease distribution.

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

    Science.gov (United States)

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

    2014-02-15

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

  16. Crystal structure of Manduca sexta prophenoloxidase provides insights into the mechanism of type 3 copper enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yongchao; Wang, Yang; Jiang, Haobo; Deng, Junpeng; (OKLU)

    2010-02-22

    Arthropod phenoloxidase (PO) generates quinones and other toxic compounds to sequester and kill pathogens during innate immune responses. It is also involved in wound healing and other physiological processes. Insect PO is activated from its inactive precursor, prophenoloxidase (PPO), by specific proteolysis via a serine protease cascade. Here, we report the crystal structure of PPO from a lepidopteran insect at a resolution of 1.97 {angstrom}, which is the initial structure for a PPO from the type 3 copper protein family. Manduca sexta PPO is a heterodimer consisting of 2 homologous polypeptide chains, PPO1 and PPO2. The active site of each subunit contains a canonical type 3 di-nuclear copper center, with each copper ion coordinated with 3 structurally conserved histidines. The acidic residue Glu-395 located at the active site of PPO2 may serve as a general base for deprotonation of monophenolic substrates, which is key to the ortho-hydroxylase activity of PO. The structure provides unique insights into the mechanism by which type 3 copper proteins differ in their enzymatic activities, albeit sharing a common active center. A drastic change in electrostatic surface induced on cleavage at Arg-51 allows us to propose a model for localized PPO activation in insects.

  17. Residual stress and electromagnetic characteristics in loop type frequency selective surface embedded hybrid structures

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyung Mi; Seo, Yun Seok; Chun, Heoung Jae [Yonsei University, Seoul (Korea, Republic of); Hong, Ik Pyo [Kongju National University, Cheonan (Korea, Republic of); Park, Yong Bae [Ajoo University, Suwon (Korea, Republic of); Kim, Yoon Jae [Agency for defense development, Daejeon (Korea, Republic of)

    2015-01-15

    Residual stresses occur in frequency-selective surface (FSS)-embedded composite structures after co-curing due to differences between the coefficients of thermal expansion between composite skins and FSSs. Furthermore, the electromagnetic characteristics may be affected by the deformation of the FSS pattern by residual stresses. Therefore, we studied the changes in electromagnetic characteristics due to the deformation of FSS, using residual stresses to deform loop-type FSS-embedded hybrid composites. We considered the effects of loop-type FSS patterns of equal dimension as well as the stacking sequences of composite laminates on the electromagnetic characteristics of FSSs: Square loop, triangular loop and circular loop. The stacking sequences of composite laminates considered in this study were [0]{sub 8}, [0/90]{sub 4}, [+-45]{sub 4} and [0/+-45/90]{sub 2}. The FSS was located between composite laminates in the middle plane. To determine the residual stresses and deformations in the FSS embedded laminate structures, the thermal loading condition in the finite element analysis was induced by cooling the hybrid structures from 125 .deg. C to 20 .deg. C based on the cure cycle of the composite. Also, the electromagnetic reflection characteristics of the hybrid structures were predicted using deformed models by residual stresses, considering the effects of stacking sequence of composite laminates. The results showed that the maximum residual stresses and deformations were produced in the [0]{sub 8} composites with all three loop-types of FSS pattern. However, the maximum resonance frequency shifts occurred in the square and triangle loop-types with stacking sequence of [0]{sub 8} , while the maximum resonance frequency shift occurred in the circular loop-type with stacking sequence of [0/+-45/90]{sub 2}.

  18. Effect of pressure on structural, electronic, mechanical and optical properties of ruthenium diboride with oP12-type structure

    Science.gov (United States)

    Aydin, S.; Ciftci, Y. O.; Mogulkoc, Y.; Tatar, A.

    2016-07-01

    The structural parameters, electronic, elastic, hardness and optical properties of oP12-type RuB2 ( Space group Pnma, No: 62) are investigated by means of density functional theory method within local-density approximation as a function of pressure. It is shown that the results at 0 GPa pressure are in good agreement with related theoretical and experimental data. The pressure dependence of elastic constants, special bond lengths, Mulliken bond populations, hardness, energy band gaps, charge densities and optical properties such as dielectric function, absorption coefficient, reflectivity function, extinction coefficient, refractive index, energy loss spectrum of oP12-type RuB2 have been investigated. It is observed that the oP12-type RuB2 compound exhibits anisotropic compressibility under hydrostatic pressure: c-direction is more compressible than a- and b-directions, due to the different bond stiffness and bond angle changes. From calculated partial density of states, Mulliken populations and 2D/3D electron densities, the nature of chemical bonding for RuB2 can be recognized as a combination of partially covalent, ionic and metallic bonds. The calculated hardness value shows that oP12- type RuB2 is hard material.

  19. Structural analysis of protein-protein interactions in type I polyketide synthases.

    Science.gov (United States)

    Xu, Wei; Qiao, Kangjian; Tang, Yi

    2013-01-01

    Polyketide synthases (PKSs) are responsible for synthesizing a myriad of natural products with agricultural, medicinal relevance. The PKSs consist of multiple functional domains of which each can catalyze a specified chemical reaction leading to the synthesis of polyketides. Biochemical studies showed that protein-substrate and protein-protein interactions play crucial roles in these complex regio-/stereo-selective biochemical processes. Recent developments on X-ray crystallography and protein NMR techniques have allowed us to understand the biosynthetic mechanism of these enzymes from their structures. These structural studies have facilitated the elucidation of the sequence-function relationship of PKSs and will ultimately contribute to the prediction of product structure. This review will focus on the current knowledge of type I PKS structures and the protein-protein interactions in this system.

  20. Interlayer-type Crystal Structure of N-(1-Adamantyl)urea

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The crystal structure of N-(1-adamantyl)urea (tricyclo[3,3,1,13,7]decan-1-urea, C11H18N2O) has been determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 13.070(2), b = 8.942(1), c = 9.390(1)(A), β = 109.819(8)°, V = 1032.5(2)(A)3, Mr = 194.27, Z = 4, Dc = 1.250 g/cm3, μ= 0.081 mm-1, F(000) = 424, R = 0.0427 and wR = 0.1076 for 1105 observed reflections with I > 2σ(I). The structure of the title compound consists of an adamantly cage which is a stable tricyclo structure with chair conformation and the substituted urea forms the interlayer-type crystal structure via hydrogen bonds between the molecules.

  1. Monitoring Structural Health of Different Types of Bridges Using Advanced Multi-Temporal InSAR

    Science.gov (United States)

    Qin, Xiaoqiong; Liao, Mingsheng; Yang, Mengshi; Zhang, Lu; Balz, Timo

    2016-08-01

    Since the bridges paly a significance role in national economic development and transportation safety, the structure health and safety of bridges aroused a lot of concern in society and become a hotspot research in earth observation and civil engineering. However, the materials degradation and environmental stresses increase may destroy the structure of bridges and pose significant risks to public safety and quality of life. This highlighted the importance of developing effective structure health monitoring strategies to reflect the current status of bridges and identify structural problems. In this work, an advanced multi-temporal InSAR technique is introduced into deformation monitoring of bridges. We focus on analysis the distribution of PSs, distinction of stable and unstable parts and recognition temporal-spatial deformation characteristics at the scale of single bridge through the examples of different types of bridges in Tianjin and Shanghai.

  2. A new tetragonal structure type for Li2B2C.

    Science.gov (United States)

    Pavlyuk, Volodymyr; Milashys, Viktoriya; Dmytriv, Grygoriy; Ehrenberg, Helmut

    2015-01-01

    The ternary dilithium diboron carbide, Li2B2C (tetragonal, space group P-4m2, tP10), crystallizes as a new structure type and consists of structural fragments which are typical for structures of elemental lithium and boron or binary borocarbide B13C2. The symmetries of the occupied sites are .m. and 2mm. for the B and C atoms, and -4m2 and 2mm. for the Li atoms. The coordination polyhedra around the Li atoms are cuboctahedra and 15-vertex distorted pseudo-Frank-Kasper polyhedra. The environment of the B atom is a ten-vertex polyhedron. The nearest neighbours of the C atom are two B atoms, and this group is surrounded by a deformed cuboctahedron with one centred lateral facet. Electronic structure calculations using the TB-LMTO-ASA method reveal strong B...C and B...B interactions.

  3. Structural basis of gate-DNA breakage and resealing by type II topoisomerases.

    Directory of Open Access Journals (Sweden)

    Ivan Laponogov

    Full Text Available Type II DNA topoisomerases are ubiquitous enzymes with essential functions in DNA replication, recombination and transcription. They change DNA topology by forming a transient covalent cleavage complex with a gate-DNA duplex that allows transport of a second duplex though the gate. Despite its biological importance and targeting by anticancer and antibacterial drugs, cleavage complex formation and reversal is not understood for any type II enzyme. To address the mechanism, we have used X-ray crystallography to study sequential states in the formation and reversal of a DNA cleavage complex by topoisomerase IV from Streptococcus pneumoniae, the bacterial type II enzyme involved in chromosome segregation. A high resolution structure of the complex captured by a novel antibacterial dione reveals two drug molecules intercalated at a cleaved B-form DNA gate and anchored by drug-specific protein contacts. Dione release generated drug-free cleaved and resealed DNA complexes in which the DNA gate instead adopts an unusual A/B-form helical conformation with a Mg(2+ ion repositioned to coordinate each scissile phosphodiester group and promote reversible cleavage by active-site tyrosines. These structures, the first for putative reaction intermediates of a type II topoisomerase, suggest how a type II enzyme reseals DNA during its normal reaction cycle and illuminate aspects of drug arrest important for the development of new topoisomerase-targeting therapeutics.

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

    Science.gov (United States)

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

    2017-08-17

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

  5. Maintaining two mating types: structure of the mating type locus and its role in heterokaryosis in Podospora anserina.

    Science.gov (United States)

    Grognet, Pierre; Bidard, Frédérique; Kuchly, Claire; Tong, Laetitia Chan Ho; Coppin, Evelyne; Benkhali, Jinane Ait; Couloux, Arnaud; Wincker, Patrick; Debuchy, Robert; Silar, Philippe

    2014-05-01

    Pseudo-homothallism is a reproductive strategy elected by some fungi producing heterokaryotic sexual spores containing genetically different but sexually compatible nuclei. This lifestyle appears as a compromise between true homothallism (self-fertility with predominant inbreeding) and complete heterothallism (with exclusive outcrossing). However, pseudohomothallic species face the problem of maintaining heterokaryotic mycelia to fully benefit from this lifestyle, as homokaryons are self-sterile. Here, we report on the structure of chromosome 1 in mat+ and mat- isolates of strain S of the pseudohomothallic fungus Podospora anserina. Chromosome 1 contains either one of the mat+ and mat- mating types of P. anserina, which is mostly found in nature as a mat+/mat- heterokaryotic mycelium harboring sexually compatible nuclei. We identified a "mat" region ∼0.8 Mb long, devoid of meiotic recombination and containing the mating-type idiomorphs, which is a candidate to be involved in the maintenance of the heterokaryotic state, since the S mat+ and S mat- strains have different physiology that may enable hybrid-vigor-like phenomena in the heterokaryons. The mat region contains 229 coding sequences. A total of 687 polymorphisms were detected between the S mat+ and S mat- chromosomes. Importantly, the mat region is colinear between both chromosomes, which calls for an original mechanism of recombination inhibition. Microarray analyses revealed that 10% of the P. anserina genes have different transcriptional profiles in S mat+ and S mat-, in line with their different phenotypes. Finally, we show that the heterokaryotic state is faithfully maintained during mycelium growth of P. anserina, yet mat+/mat+ and mat-/mat- heterokaryons are as stable as mat+/mat- ones, evidencing a maintenance of heterokaryosis that does not rely on fitness-enhancing complementation between the S mat+ and S mat- strains.

  6. Type III Radio Bursts and the Structure of the Inner Heliosphere

    Science.gov (United States)

    Reiner, M. J.

    2003-12-01

    Type III solar radio bursts provide important information on the origin, acceleration, and propagation of particles associated with solar flares and coronal shocks. Since these radio emissions are generated by the plasma emission mechanism, observations of these solar radio transients also provide remote sensing of the plasma conditions in the corona and of the magnetic and plasma structure of the inner heliosphere. In this talk I will review the progress of type III research from their discovery in the late 40s to the most recent advances from low-frequency spacecraft observations, primarily from ISEE-3, Wind and Ulysses.

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

    DEFF Research Database (Denmark)

    Lundström, Hanna; Siersma, Volkert; Nielsen, Anni B Sternhagen;

    2014-01-01

    controlled trial, 1,381 patients newly diagnosed with type 2 diabetes were randomised to 6 years of structured personal care or routine care (ClinicalTrials.gov NCT01074762). The trial had 19 years of registry-based follow-up and was analysed with Cox regression models. Repeated occurrences in the same......AIMS/HYPOTHESIS: The estimation of effect size in clinical trials commonly disregards recurrent outcomes. We investigated the effectiveness of a complex intervention on recurrent outcomes in patients with type 2 diabetes. METHODS: In the Diabetes Care in General Practice (DCGP) randomised...

  8. Synthesis of Thermostable Azo-type Photoswitches towards Photoreaulatina Nucleic Acid Structures

    Institute of Scientific and Technical Information of China (English)

    WANG Qi; GAO Shuang; ZHOU Kai; CHEN Wenbin; NIU Congwei; XI Zhen

    2009-01-01

    In order to design efficient and thermostable azo-type regulators,a series of azo-type compounds were synthesized and characterized.While introducing an inductive electron-withdrawing group to an azobenzene para or meta-position,the obtained compound can be an excellent photoswitch.3,3'-Azo-di-benzyl alcohol was designed and synthesized as one of therrnostable and efficient photoswitches,which can efficiently reversibly photoregulate the nucleic acid structure with its cis-isomer being sufficiently stable at physiological temperature.

  9. Structural and functional brain changes related to different types of physical activity across the life span.

    Science.gov (United States)

    Voelcker-Rehage, Claudia; Niemann, Claudia

    2013-11-01

    Physical activity has been shown to improve cognitive functioning. Research has largely focused on cognitive facilitation by cardiovascular exercise in older adults. Only few studies have investigated younger age groups or other types of physical activity. In this paper we review and summarize common results found in recent studies of metabolic (i.e. cardiovascular and resistance) and coordinative exercise. Findings from human motor learning are utilized to complement results on coordinative exercise. Results show that both types of exercise affect the brain differently. We propose possible mechanisms by which physical activity facilitates cognitive performance by briefly reviewing microscopic structural changes in animal research. Lastly, we highlight open research questions.

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

    Science.gov (United States)

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

    2012-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-06

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

  12. Identify Structural Flaw Location and Type with an Inverse Algorithm of Resonance Inspection

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wei; Lai, Canhai; Sun, Xin

    2015-10-20

    To evaluate the fitness-for-service of a structural component and to quantify its remaining useful life, aging and service-induced structural flaws must be quantitatively determined in service or during scheduled maintenance shutdowns. Resonance inspection (RI), a non-destructive evaluation (NDE) technique, distinguishes the anomalous parts from the good parts based on changes in the natural frequency spectra. Known for its numerous advantages, i.e., low inspection cost, high testing speed, and broad applicability to complex structures, RI has been widely used in the automobile industry for quality inspection. However, compared to other contemporary direct visualization-based NDE methods, a more widespread application of RI faces a fundamental challenge because such technology is unable to quantify the flaw details, e.g. location, dimensions, and types. In this study, the applicability of a maximum correlation-based inverse RI algorithm developed by the authors is further studied for various flaw cases. It is demonstrated that a variety of common structural flaws, i.e. stiffness degradation, voids, and cracks, can be accurately retrieved by this algorithm even when multiple different types of flaws coexist. The quantitative relations between the damage identification results and the flaw characteristics are also developed to assist the evaluation of the actual state of health of the engineering structures.

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

    Science.gov (United States)

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

    2016-10-01

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

  14. NANO-BEARING: THE DESIGN OF A NEW TYPE OF AIR BEARING WITH FLEXURE STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    KO Pui Hang; DU Ruxu

    2007-01-01

    A new type of air bearing with flexure structure is introduced. The new bearing is designed for precision mechanical engineering devices such as mechanical watch movement. The new design uses the flexure structure to provide 3D damping to absorb shocks from all directions. Two designs are presented: one has 12 T-shape slots in the radian direction while the other has 8 spiral slots in the radian direction. Both designs have flexure mountings on the axial directions. Based on the finite element analysis (FEA), the new bearing can reduce the vibration (displacement) by as much as 8.37% and hence, can better protect the shafts.

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

    DEFF Research Database (Denmark)

    Wang, Kaituo; Sitsel, Oleg; Meloni, Gabriele

    2014-01-01

    Zinc is an essential micronutrient for all living organisms. It is required for signalling and proper functioning of a range of proteins involved in, for example, DNA binding and enzymatic catalysis1. In prokaryotes and photosynthetic eukaryotes, Zn2+-transporting P-type ATPases of class IB (Znt....... The structures reveal a similar fold to Cu+-ATPases, with an amphipathic helix at the membrane interface. A conserved electronegative funnel connects this region to the intramembranous high-affinity ion-binding site and may promote specific uptake of cellular Zn2+ ions by the transporter. The E2P structure...

  16. Structure and Composition of Protein Bodies from Wild-Type and High-Lysine Barley Endosperm

    DEFF Research Database (Denmark)

    Ingversen, J.

    1975-01-01

    Protein bodies were isolated from 13 and 28 day old endosperms of barley mutant 1508 and its wild type, Bomi barley. The fine structure of the isolated protein bodies was determined by electron microscopy, and the proteins present in the preparations characterized by amino-acid analysis and SDS...... with a granular component. Particles with the same structure were present in the protein body preparation from the mutant, where, however, the granular component was the most prominent. Amino-acid composition and SDS-polyacrylamide gel electrophoresis of the proteins from the protein body preparation revealed...

  17. Structure of the Myotonic Dystrophy Type 2 RNA and Designed Small Molecules That Reduce Toxicity

    OpenAIRE

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

    2013-01-01

    Myotonic dystrophy type 2 (DM2) is an untreatable neuromuscular disorder caused by a r(CCUG) expansion (r(CCUG)exp) that folds into an extended hairpin with periodically repeating 2×2 nucleotide internal loops (5’CCUG/3’GUCC). We designed multivalent compounds that improve DM2-associated defects using information about RNA-small molecule interactions. We also report the first crystal structure of r(CCUG)exp refined to 2.35 Å. Structural analysis of the three 5’CCUG/3’GUCC repeat internal loop...

  18. The structure and properties of different types of starch exposed to UV radiation: a comparative study.

    Science.gov (United States)

    Bajer, Dagmara; Kaczmarek, Halina; Bajer, Krzysztof

    2013-10-15

    The effect of UV-irradiation on four different types of native starch (corn, waxy corn, wheat and potato) have been investigated. Although the changes in the chemical structure of starch specimens were small, indicating good photostability, the samples lost adsorbed water and their crystallinity degree decreased after irradiation. Moreover, a drop in average molecular weight occurred in samples (with the exception of potato starch) as a result of main chain scission. The variations in the properties of investigated specimens of various origin were related to the differences in their structure and macromolecular arrangement. The lowest photostability among the four starches was exhibited by potato starch.

  19. Optical properties of delta poly-type quasiregular dielectric structures made of porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, V.; Escorcia-Garcia, J. [CIICAP-UAEM, Av. Universidad 1001, Col. Chamilpa, CP 62209, Cuernavaca, Morelos (Mexico); Mora-Ramos, Miguel E. [Facultad de Ciencias-UAEM, Av. Universidad 1001, Col. Chamilpa, CP 62209, Cuernavaca, Morelos (Mexico)

    2007-05-15

    To investigate the reflection of light in quasi-regular dielectrics, we study here the optical properties of porous-silicon-based Fibonacci, Thue-Morse and Period Doubling heterostructures. The multilayered systems are fabricated in such a way that each element in the two-block substitutional sequence has a poly-type structure. Both delta-like and traditional configurations are considered. The results for the optical transmittance are analyzed and compared with the classical periodic structure. Numerical simulation for the transmittance along the lines of the transfer matrix approach is also presented. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

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

    Directory of Open Access Journals (Sweden)

    V. V. Chugunov

    2017-04-01

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

  1. Development of an Acoustic Levitation Linear Transportation System Based on a Ring-Type Structure.

    Science.gov (United States)

    Thomas, Gilles P L; Andrade, Marco A B; Adamowski, Julio Cezar; Silva, Emilio Carlos Nelli

    2017-05-01

    A linear acoustic levitation transportation system based on a ring-type vibrator is presented. The system is composed by two 21-kHz Langevin transducers connected to a ring-shaped structure formed by two semicircular sections and two flat plates. In this system, a flexural standing wave is generated along the ring structure, producing an acoustic standing wave between the vibrating ring and a plane reflector located at a distance of approximately a half wavelength from the ring. The acoustic standing wave in air has a series of pressure nodes, where small particles can be levitated and transported. The ring-type transportation system was designed and analyzed by using the finite element method. Additionally, a prototype was built and the acoustic levitation and transport of a small polystyrene particle was demonstrated.

  2. Influence of different fertilizer types of zucchini (Cucurbita pepo) on the structure of nematode communities.

    Science.gov (United States)

    Haytova, D; Bileva, T

    2011-01-01

    Increasing efficiency of production of vegetable crops is directly related to search for appropriate solution to increase their productivity. Organic amendments have been used for centuries to improve soil fertility and crop yield. Our study suggests that organic amendments can also be used as nematicidal agents. The survey was conducted on Experimental field of Department Horticulture at Agricultural University of Plovdiv, Bulgaria in 2009 on nematode infested sites. Combination with two types of fertilizers was used to investigate their effects on the community of soil nematodes. Characterization and comparative analysis among treatments of soil nematode community structure based on different ecological measures such as total nematode abundance, number of genera, trophic diversity and etc., was made. Changes in the composition and structure of nematode community as result of different fertilizer types were assessed.

  3. Electronic Structures of PbMoO4 Crystals with F-Type Colour Centres

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian-Yu; ZHANG Qi-Ren; LIU Ting-Yu; SHAO Ze-Xu; PU Chun-Ying

    2007-01-01

    Electronic structures of PbMo04 crystals containing F-type colour centres with the lattice structure optimized are studied within the framework of the fully relativistic self-consistent Dirac-SIater theory, using a numerically discrete variational (DV-Xα) method. The calculated results show that F and F+ centres have donor energy levels in the forbidden band. The optical transition energies are 2.166eV and 2.197eV, respectively, corresponding to the 580 nm absorption bands in PbMoO4 crystal. The 580 nm absorption band in PbMoO4 is originated from the F-type colour centres.

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

    DEFF Research Database (Denmark)

    Bergenholtz, Henning; Pedersen, Heidi Agerbo

    2015-01-01

    in an existing dictionary. This part of the lexicographical work is what we call structuring, which encompasses a number of various lexicographical decisions. One of these is choosing the fields that a database should contain. Typically, for some of these field types, it will be easy to distribute data......This contribution will not describe the structure in existing dictionaries. Instead, it will focus on the decisions that lexicographers make when they draw up the concept for and carry out the production of one or more new dictionaries, or when they consider making changes in the data presentation......, but for other fields it will require long considerations as there are several distribution options with different outcomes of varying usefulness. A second type of lexicographical decision to be made by the lexicographer is the predefined searching, which involves in what order searches are to be made...

  5. Analysis and Simulation of Plant Type on Canopy Structure and Radiation Transmission in Rice

    Institute of Scientific and Technical Information of China (English)

    HU Ning; LU Chuan-gen; YAO Ke-min; CHEN Jing; ZHANG Xiao-cui

    2013-01-01

    Three typical hybrid rice cultivars,together with three artificially modified plant types by the application of N fertilizer during the elongation of the two uppermost leaves were used to analyze how the plant type affected the layered leaf area and radiation transmission.Plant type factors,layered leaf area and radiation distribution were measured at the full heading,10 d and 25 d after full heading stages,respectively.A model for calculating the layered leaf area from plant type factors was established and validated to determine the effects of plant type factors on the layered leaf area for the three hybrids.Furthermore,the relationship between layered leaf area and radiation transmission was established by using the radiation transmission model.The effects of the plant type factors on the radiation transmission for the three hybrids were evaluated by using this model.Finally,a method was established to describe the canopy structure,such as the layered leaf area index and the radiation distribution in the rice canopy.

  6. Deriving and Analyzing Analytical Structures of a Class of Typical Interval Type-2 TS Fuzzy Controllers.

    Science.gov (United States)

    Zhou, Haibo; Ying, Hao

    2016-06-01

    A conventional controller's explicit input-output mathematical relationship, also known as its analytical structure, is always available for analysis and design of a control system. In contrast, virtually all type-2 (T2) fuzzy controllers are treated as black-box controllers in the literature in that their analytical structures are unknown, which inhibits precise and comprehensive understanding and analysis. In this regard, a long-standing fundamental issue remains unresolved: how a T2 fuzzy set's footprint of uncertainty, a key element differentiating a T2 controller from a type-1 (T1) controller, affects a controller's analytical structure. In this paper, we describe an innovative technique for deriving analytical structures of a class of typical interval T2 (IT2) TS fuzzy controllers. This technique makes it possible to analyze the analytical structures of the controllers to reveal the role of footprints of uncertainty in shaping the structures. Specifically, we have mathematically proven that under certain conditions, the larger the footprints, the more the IT2 controllers resemble linear or piecewise linear controllers. When the footprints are at their maximum, the IT2 controllers actually become linear or piecewise linear controllers. That is to say the smaller the footprints, the more nonlinear the controllers. The most nonlinear IT2 controllers are attained at zero footprints, at which point they become T1 controllers. This finding implies that sometimes if strong nonlinearity is most important and desired, one should consider using a smaller footprint or even just a T1 fuzzy controller. This paper exemplifies the importance and value of the analytical structure approach for comprehensive analysis of T2 fuzzy controllers.

  7. Community structure and regeneration types of Betula dahurica forest in Badaling forest center of Beijing

    Institute of Scientific and Technical Information of China (English)

    Zhang Yong; Zheng Zhi-hua; Zhang Zhi-xiang

    2007-01-01

    Using plant community analysis methods, we analyzed the floristic characteristics, species composition, community structure, population structure, and spatial distribution patterns of a Betula dahurica forest on the "1238" mountain of Badaling in Beijing, China. The results show that: 1) There are 33 plant species in the B. dahurica community, including 18 woody plant species. The B. dahurica forest is a monodominant community with 75.9% dominance. 2) Based on diameter at breast height (DBH)size class distribution, the population structure of B. dahurica and Acer mono-two heliophyllous and pioneer tree species is cascade-type, with both in an increasing stage. The population structure of Tilia mandshurica and T. mongolica, two shade-tolerant tree species, is inverse-J type, and they have more young seedling individuals and regenerate more stably. They are associated species of the pioneer tree species. The population structure of Quercus mongolica, as the associated species of climax species in the community, is sporadic, and its regeneration is fluctuating and random. Fraxinus rhynchophylla is a shade-tolerant tree species which has a unibar population structure and climax characteristics of pioneer tree species. The relative frequency of young seedlings reached 0.4.3) The dominant species B. dahurica is still in an increasing stage, and the regeneration of other species is steady or partly influences the community, putting the community in the pioneer species stage. From the population structure and distribution frequency ofF. rhynchophylla, the B. dahurica forest will approach to a climax state in the future.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-01

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

  9. The vibration of a box-type structure. II - Response to a travelling pressure wave.

    Science.gov (United States)

    Popplewell, N.

    1971-01-01

    A finite element method is formulated for determining the transient response of a box-type structure to a traveling, arbitrarily shaped pressure wave. The method is illustrated by considering an example of practical concern - the sonic boom. The acceleration-time histories of a closed box are compared with those obtained experimentally from a simulated boom. Satisfactory agreement is obtained with only four rectangular elements per individual face and a simplified loading of the box.

  10. Comparison of the Behaviour of Curved and Straight Types of Steel Shell Roof Structures

    OpenAIRE

    Behnamasl, Mana

    2010-01-01

    ABSTRACT: In this research, the straight and curved models of the steel shell roof with different plates were analysed, designed and the results were compared with one another. Through this exercise it is aimed at achieving an ideal shell roof structure which could cover a larger surface. Therefore, three types of shell roofs were considered duopitch, cylindrical and dome and the main objective was to compare the straight and curved model of the shells. According to the findings of the liter...

  11. Van der Waals Type Model and Structure in π-p Elastic Scattering at High Energies

    Science.gov (United States)

    Aleem, F.

    1982-10-01

    The most recent measurement of the angular distribution for π-p elastic scattering at pL =50 and 200 GeV/c which show a structure near -t ≈ 4(GeV/c)2, with squared four momentum transfer -t extended to 10(GeV/c)2, and the total cross section data for 50 ≤ pL ≤ 370 GeV/c have been simultaneously explained by using Van der Waal's type model.

  12. Structure of the minor pseudopilin XcpW from the Pseudomonas aeruginosa type II secretion system

    Energy Technology Data Exchange (ETDEWEB)

    Franz, Laura P.; Douzi, Badreddine; Durand, Eric; Dyer, David H.; Voulhouxd, Romé; Forest, Katrina T. (CNRS-UMR); (CNRS-CRMD); (UW)

    2012-01-13

    Pseudomonas aeruginosa utilizes the type II secretion machinery to transport virulence factors through the outer membrane into the extracellular space. Five proteins in the type II secretion system share sequence homology with pilin subunits of type IV pili and are called the pseudopilins. The major pseudopilin X{sub cp}T{sub G} assembles into an intraperiplasmic pilus and is thought to act in a piston-like manner to push substrates through an outer membrane secretin. The other four minor pseudopilins, X{sub cp}U{sub H}, X{sub cp}V{sub I}, X{sub cp}W{sub J} and X{sub cp}X{sub K}, play less well defined roles in pseudopilus formation. It was recently discovered that these four minor pseudopilins form a quaternary complex that is presumed to initiate the formation of the pseudopilus and to localize to its tip. Here, the structure of X{sub cp}W{sub J} was refined to 1.85 {angstrom} resolution. The structure revealed the type IVa pilin fold with an embellished variable antiparallel {beta}-sheet as also found in the X{sub cp}W{sub J} homologue enterotoxigenic Escherichia coli G{sub sp}J{sub W} and the X{sub cp}U{sub H} homologue Vibrio cholerae E{sub ps}U{sub H}. It is proposed that the exposed surface of this sheet may cradle the long N-terminal 1 helix of another pseudopilin. The final 31 amino acids of the X{sub cp}W{sub J} structure are instrinsically disordered. Deletion of this unstructured region of X{sub cp}W{sub J} did not prevent type II secretion in vivo.

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

    Science.gov (United States)

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

    2012-05-01

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

  14. Study of macroporous silicon electrochemical etching in 3D structured N type silicon substrates

    Energy Technology Data Exchange (ETDEWEB)

    Kouassi, Sebastien; Gautier, Gael; Desplobain, Sebastien; Ventura, Laurent [Laboratoire de Microelectronique de Puissance, Universite Francois Rabelais Tours, 16 Rue Pierre et Marie Curie, 37071 Tours Cedex 2 (France)

    2011-06-15

    In this paper, the electrochemical etching of 3D n-type substrates is investigated. These types of 3D structures are of interest to increase the active surface of some systems. Our aim is to improve a MEMS (Micro-Electro Mechanical System) micro fuel cell power through total surface enhancement without any modification of the cell footprint. To reach this objective, we perform a gas diffusion layer using localized macro-porous silicon. The porous area total surface is improved through trench formation (before porous silicon etching). This is supposed to allow a better power to surface ratio for manufactured fuel cell. The Figure on the right hand side introduces the aimed MEMS based micro fuel cell. The geometrical parameters of the designed structures and the manufacturing process influence are presented. To perform 3D structures, two types of anisotropic etching techniques have been used, alkaline etching of silicon and deep reactive ion etching (DRIE). Additional steps such as a doping layer have been used to improve the results obtained with the initial micro-fabrication process. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

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

    Science.gov (United States)

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

    2015-07-01

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

  16. THE EFFECTS OF SEX, TOPOLOGICAL STRUCTURE, AND TASK TYPE ON HYPERTEXT NAVIGATIONAL PERFORMANCE.

    Science.gov (United States)

    Chang, Wen-Te; Chien, Yu-Hung

    2015-06-01

    Currently, almost all online materials use hyperlinks to provide users access to background, supplemental, or alternative information presented in context, greatly increasing the potential integration of information. However, a major problem is that people do not navigate hyperlinks effectively when the links become more topologically complex. Thus, identification of the variables that lead to navigational errors is necessary for the effective design of hyperlinks. Ninety-one participants (45 women, 46 men) were recruited for this experiment. All were college students and ranged in age from 19 to 23 yr. (M = 20.87, SD = 1.02). Navigational performance was examined in relation to sex, topological structure, and task type. A network topology with single-node task was superior to one with a linear topology under a single-node task condition, but equal to one with a linear topology under a multi-node task condition. Men navigated the linear topology with multi-node task and a network topology with a single-node task significantly faster than women, whereas no significant differences were observed under the other conditions. Sex interacted with topological structure and task type. This study extended the research in this domain by demonstrating an interactive effect among sex, topological structure, and task type on the navigational performance of users and can contribute to research regarding web page design.

  17. Excitonic structure and pumping power dependent emission blue-shift of type-II quantum dots

    Science.gov (United States)

    Klenovský, Petr; Steindl, Petr; Geffroy, Dominique

    2017-01-01

    In this work we study theoretically and experimentally the multi-particle structure of the so-called type-II quantum dots with spatially separated electrons and holes. Our calculations based on customarily developed full configuration interaction ap- proach reveal that exciton complexes containing holes interacting with two or more electrons exhibit fairly large antibinding energies. This effect is found to be the hallmark of the type-II confinement. In addition, an approximate self-consistent solution of the multi-exciton problem allows us to explain two pronounced phenomena: the blue-shift of the emission with pumping and the large inhomogeneous spectral broadening, both of those eluding explanation so far. The results are confirmed by detailed intensity and polarization resolved photoluminescence measurements on a number of type-II samples. PMID:28358120

  18. Structural and Morphometric Comparison of Lower Incisors in PACAP-Deficient and Wild-Type Mice.

    Science.gov (United States)

    Sandor, B; Fintor, K; Reglodi, D; Fulop, D B; Helyes, Z; Szanto, I; Nagy, P; Hashimoto, H; Tamas, A

    2016-06-01

    Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide with widespread distribution. PACAP plays an important role in the development of the nervous system, it has a trophic and protective effect, and it is also implicated in the regulation of various physiological functions. Teeth are originated from the mesenchyme of the neural crest and the ectoderm of the first branchial arch, suggesting similarities with the development of the nervous system. Earlier PACAP-immunoreactive fibers have been found in the odontoblastic and subodontoblastic layers of the dental pulp. Our previous examinations have shown that PACAP deficiency causes alterations in the morphology and structure of the developing molars of 7-day-old mice. In our present study, morphometric and structural comparison was performed on the incisors of 1-year-old wild-type and PACAP-deficient mice. Hard tissue density measurements and morphometric comparison were carried out on the mandibles and the lower incisors with micro-CT. For structural examination, Raman microscopy was applied on frontal thin sections of the mandible. With micro-CT morphometrical measurements, the size of the incisors and the relative volume of the pulp to dentin were significantly smaller in the PACAP-deficient group compared to the wild-type animals. The density of calcium hydroxyapatite in the dentin was reduced in the PACAP-deficient mice. No structural differences could be observed in the enamel with Raman microscopy. Significant differences were found in the dentin of PACAP-deficient mice with Raman microscopy, where increased carbonate/phosphate ratio indicates higher intracrystalline disordering. The evaluation of amide III bands in the dentin revealed higher structural diversity in wild-type mice. Based upon our present and previous results, it is obvious that PACAP plays an important role in tooth development with the regulation of morphogenesis, dentin, and enamel mineralization. Further studies are

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

    Science.gov (United States)

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

    2012-01-01

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

  20. Evidence of organic structures in Ediacara-type fossils and associated microbial mats

    Science.gov (United States)

    Steiner, Michael; Reitner, Joachim

    2001-12-01

    Ediacara-type fossils represent a group of soft-bodied organisms, mainly known from imprints in Proterozoic coarse-grained siliciclastic sedimentary rocks. Circular compressions of Beltanelliformis brunsae and remains related to Ediacara-type fossils, such as Cucullus fraudulentus, and Mucuplagum primitivum are reported here in an organic mode of preservation from the Neoproterozoic Doushantuo and Liulaobei Formations of China. They can be interpreted as prokaryotic colonies. A charnid fossil with circular attachment disc and stalk, but torn-off frond, is documented in a three-dimensional and partly organic mode of preservation from the Neoproterozoic Ust-Pinega Formation (White Sea coast, Russia). According to their morphology and structure, the Charniidae are not regarded by us as pennatulaceans. Modern Myxobacteria illustrate that macroscopic size, complexity, and even compartmentalization can also be developed by prokaryotic colonies. Part of the Ediacara-type fossils may therefore represent prokaryotic colonies or symbiotic organisms involving prokaryotes. Finally, direct evidence indicates that biofilms with associated prokaryotic sheaths, preserved in both organic and pyritic fashion, form the wrinkled surfaces (“elephant skin”) that were preferentially colonized by Ediacara-type fossils. This finding supports previous interpretations, based on comparative morphological and sedimentological approaches, that ancient wrinkle structures were microbial mats.

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

    Science.gov (United States)

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

    2015-07-01

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

  2. Inhibition Kinetics and Emodin Cocrystal Structure of a Type II Polyketide Ketoreductase†,‡

    Science.gov (United States)

    Korman, Tyler Paz; Tan, Yuhong; Wong, Justin; Luo, Rui; Tsai, Shiou-Chuan

    2008-01-01

    Type II polyketides are a class of natural products that include pharmaceutically important aromatic compounds such as the antibiotic tetracycline and antitumor compound doxorubicin. The type II polyketide synthase (PKS) is a complex consisting of 5–10 standalone domains homologous to fatty acid synthase (FAS). Polyketide ketoreductase (KR) provides regio- and stereochemical diversity during the reduction. How the type II polyketide KR specifically reduces only the C9 carbonyl group is not well understood. The cocrystal structures of actinorhodin polyketide ketoreductase (actKR) bound with NADPH or NADP+ and the inhibitor emodin were solved with the wild type and P94L mutant of actKR, revealing the first observation of a bent p-quinone in an enzyme active site. Molecular dynamics simulation help explain the origin of the bent geometry. Extensive screening for in vitro substrates shows that unlike FAS KR, the actKR prefers bicyclic substrates. Inhibition kinetics indicate that actKR follows an ordered Bi Bi mechanism. Together with docking simulations that identified a potential phosphopantetheine binding groove, the structural and functional studies reveal that the C9 specificity is a result of active site geometry and substrate ring constraints. The results lay the foundation for the design of novel aromatic polyketide natural products with different reduction patterns. PMID:18205400

  3. Inhibition kinetics and emodin cocrystal structure of a type II polyketide ketoreductase.

    Science.gov (United States)

    Korman, Tyler Paz; Tan, Yu-Hong; Wong, Justin; Luo, Ray; Tsai, Shiou-Chuan

    2008-02-19

    Type II polyketides are a class of natural products that include pharmaceutically important aromatic compounds such as the antibiotic tetracycline and antitumor compound doxorubicin. The type II polyketide synthase (PKS) is a complex consisting of 5-10 standalone domains homologous to fatty acid synthase (FAS). Polyketide ketoreductase (KR) provides regio- and stereochemical diversity during the reduction. How the type II polyketide KR specifically reduces only the C9 carbonyl group is not well understood. The cocrystal structures of actinorhodin polyketide ketoreductase (actKR) bound with NADPH or NADP+ and the inhibitor emodin were solved with the wild type and P94L mutant of actKR, revealing the first observation of a bent p-quinone in an enzyme active site. Molecular dynamics simulation help explain the origin of the bent geometry. Extensive screening for in vitro substrates shows that unlike FAS KR, the actKR prefers bicyclic substrates. Inhibition kinetics indicate that actKR follows an ordered Bi Bi mechanism. Together with docking simulations that identified a potential phosphopantetheine binding groove, the structural and functional studies reveal that the C9 specificity is a result of active site geometry and substrate ring constraints. The results lay the foundation for the design of novel aromatic polyketide natural products with different reduction patterns.

  4. 18-Electron Resonance Structures in the BCC Transition Metals and Their CsCl-type Derivatives.

    Science.gov (United States)

    Vinokur, Anastasiya I; Fredrickson, Daniel C

    2017-03-06

    Bonding in elemental metals and simple alloys has long been thought of as involving intense delocalization, with little connection to the localized bonds of covalent systems. In this Article, we show that the bonding in body-centered cubic (bcc) structures of the group 6 transition metals can in fact be represented, via the concepts of the 18-n rule and isolobal bonding, in terms of two balanced resonance structures. We begin with a reversed approximation Molecular Orbital (raMO) analysis of elemental Mo in its bcc structure. The raMO analysis indicates that, despite the low electron count (six valence electrons per Mo atom), nine electron pairs can be associated with any given Mo atom, corresponding to a filled 18-electron configuration. Six of these electron pairs take part in isolobal bonds along the second-nearest neighbor contacts, with the remaining three (based on the t2g d orbitals) interacting almost exclusively with first-nearest neighbors. In this way, each primitive cubic network defined by the second-nearest neighbor contacts comprises an 18-n electron system with n = 6, which essentially describes the full electronic structure of the phase. Of course, either of the two interpenetrating primitive cubic frameworks of the bcc structure can act as a basis for this discussion, leading us to write two resonance structures with equal weights for bcc-Mo. The electronic structures of CsCl-type variants with the same electron count can then be interpreted in terms of changing the relative weights of these two resonance structures, as is qualitatively confirmed with raMO analysis. This combination of raMO analysis with the resonance concept offers an avenue to extend the 18-n rule into other transition metal-rich structures.

  5. How similar is the stellar structure of low-mass late-type galaxies to that of early-type dwarfs?

    CERN Document Server

    Janz, Joachim; Laine, Jarkko; Salo, Heikki; Lisker, Thorsten

    2016-01-01

    We analyse structural decompositions of 500 late-type galaxies (Hubble $T$-type $\\ge 6$) from the Spitzer Survey of Stellar Structure in Galaxies (S$^4$G), spanning a stellar mass range of about $10^7$ to a few times $10^{10}$ M$_\\odot$. Their decomposition parameters are compared with those of the early-type dwarfs in the Virgo cluster from Janz et al. They have morphological similarities, including the fact that the fraction of simple one-component galaxies in both samples increases towards lower galaxy masses. We find that in the late-type two-component galaxies both the inner and outer structures are by a factor of two larger than those in the early-type dwarfs, for the same stellar mass of the component. While dividing the late-type galaxies to low and high density environmental bins, it is noticeable that both the inner and outer components of late types in the high local galaxy density bin are smaller, and lie closer in size to those of the early-type dwarfs. This suggests that, although structural dif...

  6. Mushroom-type structures with the wires connected through diodes: Theory and applications

    Science.gov (United States)

    Forouzmand, Ali; Kaipa, Chandra S. R.; Yakovlev, Alexander B.

    2016-07-01

    In this paper, we establish a general formalism to quantify the interaction of electromagnetic waves with mushroom-type structures (high impedance surface and bi-layer) with diodes inserted along the direction of the wires. The analysis is carried out using the nonlocal homogenization model for the mushroom structure with the generalized additional boundary conditions at the connection of the wires to diodes. We calculate numerically the magnitude and phase of the reflected/transmitted fields in the presence of an ideal and realistic PIN diodes. It is observed that the reflection/transmission characteristics of the mushroom-type structures can be controlled by tuning the working states of the integrated PIN diodes. We realize a structure with a multi-diode switch to minimize the undesired transmission for a particular incident angle. In addition, a dual-band subwavelength imaging lens is designed based on the resonant amplification of evanescent waves, wherein the operating frequency can be tuned by changing the states of the PIN diodes. The analytical results are verified with the full-wave electromagnetic solver CST Microwave Studio, showing a good agreement.

  7. Crystal structure of a copper-transporting PIB-type ATPase

    DEFF Research Database (Denmark)

    Gourdon, Pontus; Liu, Xiang-Yu; Skjørringe, Tina

    2011-01-01

    Heavy-metal homeostasis and detoxification is crucial for cell viability. P-type ATPases of the class IB (PIB) are essential in these processes, actively extruding heavy metals from the cytoplasm of cells. Here we present the structure of a PIB-ATPase, a Legionella pneumophila CopA Cu(+)-ATPase, ......Heavy-metal homeostasis and detoxification is crucial for cell viability. P-type ATPases of the class IB (PIB) are essential in these processes, actively extruding heavy metals from the cytoplasm of cells. Here we present the structure of a PIB-ATPase, a Legionella pneumophila CopA Cu......(+)-ATPase, in a copper-free form, as determined by X-ray crystallography at 3.2 Å resolution. The structure indicates a three-stage copper transport pathway involving several conserved residues. A PIB-specific transmembrane helix kinks at a double-glycine motif displaying an amphipathic helix that lines a putative...... copper entry point at the intracellular interface. Comparisons to Ca(2+)-ATPase suggest an ATPase-coupled copper release mechanism from the binding sites in the membrane via an extracellular exit site. The structure also provides a framework to analyse missense mutations in the human ATP7A and ATP7B...

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

    Science.gov (United States)

    Kano, Shingo; Tsuchiya, Noriyoshi

    2006-05-01

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

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

    Science.gov (United States)

    Chatellard, Lucile; Trably, Eric; Carrère, Hélène

    2016-12-01

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

  10. Anisotropic thermoelectric properties in layered complex nitrides with α-NaFeO2-type structure

    Directory of Open Access Journals (Sweden)

    Isao Ohkubo

    2016-10-01

    Full Text Available Electronic structures and thermoelectric transport properties of α-NaFeO2-type d0-electron layered complex nitrides AMN2 (A = Sr or Na; M = Zr, Hf, Nb, Ta were evaluated using density-functional theory and Boltzmann theory calculations. Despite the layered crystal structure, all materials had three-dimensional electronic structures. Sr(Zr, HfN2 exhibited isotropic electronic transport properties because of the contribution of the Sr 4d orbitals to the conduction band minimums (CBMs in addition to that of the Zr 4d (Hf 5d orbitals. Na(Nb,TaN2 showed weak anisotropic electronic transport properties due to the main contribution of the Nb 4d (Ta 5d and N 2p orbitals to the CBMs and no contribution of the Na orbitals.

  11. Elastic stability and electronic structure of pyrite type PtN2: Ahard semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Rong; Zhan, Qian; Zhang, Xiao-Feng

    2006-08-29

    The elastic properties and electronic structure of PtN2 withthe pyrite structure (PtN2(C2)) were studied with first-principlescalculations. The crystal structure is demonstrated to be elasticallystable with a lower energy than the metastable fluorite structureproposed before. The calculated shear modulus of 214 GPa suggests thatPtN2(C2) is harder than some well known hard materials such as TiN andSiC. The high elastic moduli are attributed to a stacking ofcorner-shared PtN6 octahedra bonded by strong N-N covalent bonding. Incontrast to the metallic fluorite-type phase, PtN2(C2) is semiconductingwith an indirect band gap.

  12. An Improved Finite Difference Type Numerical Method for Structural Dynamic Analysis

    Directory of Open Access Journals (Sweden)

    Sung-Hoon Kim

    1994-01-01

    Full Text Available An improved finite difference type numerical method to solve partial differential equations for one-dimensional (1-D structure is proposed. This numerical scheme is a kind of a single-step, second-order accurate and implicit method. The stability, consistency, and convergence are examined analytically with a second-order hyperbolic partial differential equation. Since the proposed numerical scheme automatically satisfies the natural boundary conditions and at the same time, all the partial differential terms at boundary points are directly interpretable to their physical meanings, the proposed numerical scheme has merits in computing 1-D structural dynamic motion over the existing finite difference numeric methods. Using a numerical example, the suggested method was proven to be more accurate and effective than the well-known central difference method. The only limitation of this method is that it is applicable to only 1-D structure.

  13. Structures of rare earth-transition metal rich compounds derived from CaCu5 type

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The properties of materials have a close connect ion to their crystal structures. Rare earth (R)-transition metal (T) rich compo und are the focus of investigation in the search for new hard magnetic materials . As the basis for the study of stabilized effect of the third component on the fo rmation of RT5 derivative and its influence of the occupied sites on magnetic properties, in this paper, the possible derivative compounds based on the RT5 primitive unit cell of the CaCu5 structure type formed through the ordered or disordered substitution of dumbbell pair 2T atoms for the R atoms at some sit es, and the structural relationship between the derivatives and the prototype ar e summarized.

  14. Anisotropic thermoelectric properties in layered complex nitrides with α-NaFeO2-type structure

    Science.gov (United States)

    Ohkubo, Isao; Mori, Takao

    2016-10-01

    Electronic structures and thermoelectric transport properties of α-NaFeO2-type d0-electron layered complex nitrides AMN2 (A = Sr or Na; M = Zr, Hf, Nb, Ta) were evaluated using density-functional theory and Boltzmann theory calculations. Despite the layered crystal structure, all materials had three-dimensional electronic structures. Sr(Zr, Hf)N2 exhibited isotropic electronic transport properties because of the contribution of the Sr 4d orbitals to the conduction band minimums (CBMs) in addition to that of the Zr 4d (Hf 5d) orbitals. Na(Nb,Ta)N2 showed weak anisotropic electronic transport properties due to the main contribution of the Nb 4d (Ta 5d) and N 2p orbitals to the CBMs and no contribution of the Na orbitals.

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

    Science.gov (United States)

    Salter, Daniel W.; Vandiver, Beverly J.

    2002-01-01

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

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

    Science.gov (United States)

    Salter, Daniel W.; Vandiver, Beverly J.

    2002-01-01

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

  17. Data with hierarchical structure: impact of intraclass correlation and sample size on type-I error.

    Science.gov (United States)

    Musca, Serban C; Kamiejski, Rodolphe; Nugier, Armelle; Méot, Alain; Er-Rafiy, Abdelatif; Brauer, Markus

    2011-01-01

    Least squares analyses (e.g., ANOVAs, linear regressions) of hierarchical data leads to Type-I error rates that depart severely from the nominal Type-I error rate assumed. Thus, when least squares methods are used to analyze hierarchical data coming from designs in which some groups are assigned to the treatment condition, and others to the control condition (i.e., the widely used "groups nested under treatment" experimental design), the Type-I error rate is seriously inflated, leading too often to the incorrect rejection of the null hypothesis (i.e., the incorrect conclusion of an effect of the treatment). To highlight the severity of the problem, we present simulations showing how the Type-I error rate is affected under different conditions of intraclass correlation and sample size. For all simulations the Type-I error rate after application of the popular Kish (1965) correction is also considered, and the limitations of this correction technique discussed. We conclude with suggestions on how one should collect and analyze data bearing a hierarchical structure.

  18. Data with hierarchical structure: impact of intraclass correlation and sample size on Type-I error

    Directory of Open Access Journals (Sweden)

    Serban C Musca

    2011-04-01

    Full Text Available Least squares analyses (e.g., ANOVAs, linear regressions of hierarchical data leads to Type-I error rates that depart severely from the nominal Type-I error rate assumed. Thus, when least squares methods are used to analyze hierarchical data coming from designs in which some groups are assigned to the treatment condition, and others to the control condition (i.e., the widely used "groups nested under treatment" experimental design, the Type-I error rate is seriously inflated, leading too often to the incorrect rejection of the null hypothesis (i.e., the incorrect conclusion of an effect of the treatment. To highlight the severity of the problem, we present simulations showing how the Type-I error rate is affected under different conditions of intraclass correlation and sample size. For all simulations the Type-I error rate after application of the popular Kish (1965 correction is also considered, and the limitations of this correction technique discussed. We conclude with suggestions on how one should collect and analyze data bearing a hierarchical structure.

  19. Synthesis and crystal structures of C24-epimeric 20(R)-ocotillol-type saponins.

    Science.gov (United States)

    Xu, Yang Rong; Yang, Jing Jing; Liu, Juan; Hou, Gui Ge; Meng, Qing Guo

    2016-06-01

    Ocotillol-type saponins have a wide spectrum of biological activities. Previous studies indicated that the configuration at the C24 position may be responsible for their stereoselectivity in pharmacological action and pharmacokinetics. Natural ocotillol-type saponins share a 20(S)-form but it has been found that the 20(R)-stereoisomers have different pharmacological effects. The semisynthesis of 20(R)-ocotillol-type saponins has not been reported and it is therefore worthwhile clarifying their crystal structures. Two C24 epimeric 20(R)-ocotillol-type saponins, namely (20R,24S)-20,24-epoxydammarane-3β,12β,25-triol, C30H52O4, (III), and (20R,24R)-20,24-epoxydammarane-3β,12β,25-triol monohydrate, C30H52O4·H2O, (IV), were synthesized, and their structures were elucidated by spectral studies and finally confirmed by single-crystal X-ray diffraction. The (Me)C-O-C-C(OH) torsion angle of (III) is 146.41 (14)°, whereas the corresponding torsion angle of (IV) is -146.4 (7)°, indicating a different conformation at the C24 position. The crystal stacking in (III) generates an R4(4)(8) motif, through which the molecules are linked into a one-dimensional double chain. The chains are linked via nonclassical C-H...O hydrogen bonds into a two-dimensional network, and further stacked into a three-dimensional structure. In contrast to (III), epimer (IV) crystallizes as a hydrate, in which the water molecules act as hydrogen-bond donors linking one-dimensional chains into a two-dimensional network through intermolecular O-H...O hydrogen bonds. The hydrogen-bonded chains extend helically along the crystallographic a axis and generate a C4(4)(8) motif.

  20. High pressure structures of "111" type iron-based superconductors predicted from first-principles.

    Science.gov (United States)

    Zhang, Xinxin; Wang, Yanchao; Ma, Yanming

    2012-11-21

    The high-pressure crystal structures of the "111" type iron-based superconductors: NaFeAs, LiFeP and LiFeAs have been systematically explored by using particle-swarm structural searches. It was found that though these iron-based superconductors are chemically similar, they adopted distinct structural phase transitions: P4/nmm→Cmcm→P3m1 for NaFeAs, P4/nmm→Cmcm→I4mm for LiFeP, and P4/nmm→P3m1 →I4mm→P6(3)/mmc for LiFeAs under high pressure. The high pressure orthorhombic Cmcm phase preserved the structural features of FeX(4)(X = As, P) tetrahedral layers present in the ambient-pressure P4/nmm structure. However, the FeX(4) tetrahedrons in the Cmcm phase were clearly distorted, leading to changes in the electronic behavior around the Fermi level. Under higher pressures, the FeX(4) layered structural features were no longer persistent and three-dimensional crystal structures were stabilized in other P3m1, I4mm, and P6(3)/mmc phases, which featured FeAs(5)/FeAs(6) hexahedron and octahedrons, FeX(5) tetragonal pyramids, and FeAs(6) octahedrons, respectively. Analysis of the electronic density of states suggests that most of the high pressure phases are metallic except for the tetragonal I4mm phase, which possesses a narrow band gap. This semiconducting state might relate to the tetragonal pyramid structure formed by FeX(5) unit, which might be favorable for charge localization.

  1. A density functional study of the chemical differences between Type I and Type II MoS2-based structures in hydrotreating catalysts.

    Science.gov (United States)

    Hinnemann, Berit; Nørskov, Jens K; Topsøe, Henrik

    2005-02-17

    Density functional theory is used to investigate the origin of the activity differences between Type I and Type II MoS2-based structures in hydrotreating catalysts. It is well known that the Type II structures, where only weak interactions with the support exist, have a higher catalytic activity than Type I structures, where Mo-O linkages to the alumina are present. The present results show that the differences in activities for MoS2 and Co-Mo-S structures can be attributed to the electronic and bonding differences introduced by the bridging O bonds. We find that the Mo-O linkages are most probably located on the (1010) S edge. The presence of oxygen linkages increases the energy required to form sulfur vacancies significantly so that almost no vacancies can be formed at these and neighboring sites. In this way, the reactivity of the S edge is reduced. In addition, the studies also show that the linkages introduce changes in the one-dimensional metallic-like brim states. Furthermore, the presence of oxygen linkages also changes the energetics of hydrogen adsorption, which becomes less exothermic on sulfur sites directly above linkages and more exothermic on sulfur sites adjacent to linkages. The present results explain previously observed differences in Type I-Type II transition temperatures for Co-Mo-S structures with different Co contents.

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

    Science.gov (United States)

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

    2010-01-01

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

  3. Experimental evidence for pressure-induced first order transition in cerium nitride from B1 to B10 structure type

    Science.gov (United States)

    Nielsen, Morten B.; Ceresoli, Davide; Jørgensen, Jens-Erik; Prescher, Clemens; Prakapenka, Vitali B.; Bremholm, Martin

    2017-01-01

    The crystal structure of CeN was investigated up to pressures of 82 GPa, using diamond anvil cell powder X-ray diffraction in two experiments with He and Si-oil as the pressure transmitting media. In contrast to previous reports, we do not observe the B2 (CsCl type) structure at high pressure. Instead, the structural phase transition, starting at 65 GPa, from the ambient rock salt B1 structure results in a distorted CsCl-like B10 structure, irrespective of the pressure medium. Our result unambiguously confirms two recent density functional theory (DFT) studies predicting the B10 phase to be stable at these pressures, rather than the B2 (CsCl type) phase previously reported. The B10 structure appears to approach the B2 structure as pressure is increased further, but DFT calculations indicate that an L10 structure (AuCu type) is energetically favored.

  4. Structure of a human monoclonal antibody Fab fragment against gp41 of human immunodeficiency virus type

    Science.gov (United States)

    He, X. M.; Ruker, F.; Casale, E.; Carter, D. C.

    1992-01-01

    The three-dimensional structure of a human monoclonal antibody (Fab), which binds specifically to a major epitope of the transmembrane protein gp41 of the human immunodeficiency virus type 1, has been determined by crystallographic methods to a resolution of 2.7 A. It has been previously determined that this antibody recognizes the epitope SGKLICTTAVPWNAS, belongs to the subclass IgG1 (kappa), and exhibits antibody-dependent cellular cytotoxicity. The quaternary structure of the Fab is in an extended conformation with an elbow bend angle between the constant and variable domains of 175 degrees. Structurally, four of the hypervariable loops can be classified according to previously recognized canonical structures. The third hypervariable loops of the heavy (H3) and light chain (L3) are structurally distinct. Hypervariable loop H3, residues 102H-109H, is unusually extended from the surface. The complementarity-determining region forms a hydrophobic binding pocket that is created primarily from hypervariable loops L3, H3, and H2.

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

    Science.gov (United States)

    Ruiz, Federico M; Santillana, Elena; Spínola-Amilibia, Mercedes; Torreira, Eva; Culebras, Esther; Romero, Antonio

    2015-01-01

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

  6. A Salmonella type three secretion effector/chaperone complex adopts a hexameric ring-like structure.

    Science.gov (United States)

    Roblin, Pierre; Dewitte, Frédérique; Villeret, Vincent; Biondi, Emanuele G; Bompard, Coralie

    2015-02-15

    Many bacterial pathogens use type three secretion systems (T3SS) to inject virulence factors, named effectors, directly into the cytoplasm of target eukaryotic cells. Most of the T3SS components are conserved among plant and animal pathogens, suggesting a common mechanism of recognition and secretion of effectors. However, no common motif has yet been identified for effectors allowing T3SS recognition. In this work, we performed a biochemical and structural characterization of the Salmonella SopB/SigE chaperone/effector complex by small-angle X-ray scattering (SAXS). Our results showed that the SopB/SigE complex is assembled in dynamic homohexameric-ring-shaped structures with an internal tunnel. In this ring, the chaperone maintains a disordered N-terminal end of SopB molecules, in a good position to be reached and processed by the T3SS. This ring dimensionally fits the ring-organized molecules of the injectisome, including ATPase hexameric rings; this organization suggests that this structural feature is important for ATPase recognition by T3SS. Our work constitutes the first evidence of the oligomerization of an effector, analogous to the organization of the secretion machinery, obtained in solution. As effectors share neither sequence nor structural identity, the quaternary oligomeric structure could constitute a strategy evolved to promote the specificity and efficiency of T3SS recognition.

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

    Directory of Open Access Journals (Sweden)

    Federico M Ruiz

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

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

    Science.gov (United States)

    Bolsman, Caspar T.; Goosen, Johannes F. L.; van Keulen, Fred

    2008-03-01

    In this paper, we illustrate and study the opportunities of resonant ring type structures as wing actuation mechanisms for a flapping wing Micro Air Vehicle (MAV). Various design alternatives are presented and studied based on computational and physical models. Insects provide an excellent source of inspiration for the development of the wing actuation mechanisms for flapping wing MAVs. The insect thorax is a structure which in essence provides a mechanism to couple the wing muscles to the wings while offering weight reduction through application of resonance, using tailored elasticity. The resonant properties of the thorax are a very effective way to reducing the power expenditure of wing movement. The wing movement itself is fairly complex and is guided by a set of control muscles and thoracic structures which are present in proximity of the wing root. The development of flapping wing MAVs requires a move away from classical structures and actuators. The use of gears and rotational electric motors is hard to justify at the small scale. Resonant structures provide a large design freedom whilst also providing various options for actuation. The move away from deterministic mechanisms offers possibilities for mass reduction.

  9. The Spectra of Type IIB Flux Compactifications at Large Complex Structure

    CERN Document Server

    Brodie, Callum

    2015-01-01

    We compute the spectra of the Hessian matrix, ${\\cal H}$, and the matrix ${\\cal M}$ that governs the critical point equation of the low-energy effective supergravity, as a function of the complex structure and axio-dilaton moduli space in type IIB flux compactifications at large complex structure. We find both spectra analytically in an $h^{1,2}_-+3$ real-dimensional subspace of the moduli space, and show that they exhibit a universal structure with highly degenerate eigenvalues, independently of the choice of flux, the details of the compactification geometry, and the number of complex structure moduli. In this subspace, the spectrum of the Hessian matrix contains no tachyons, but there are also no critical points. We show numerically that the spectra of ${\\cal H}$ and ${\\cal M}$ remain highly peaked over a large fraction of the sampled moduli space of explicit Calabi-Yau compactifications with 2 to 5 complex structure moduli. In these models, the scale of the supersymmetric contribution to the scalar masses...

  10. Structural definition on the surface of Helicobacter pylori type IV secretion apparatus.

    Science.gov (United States)

    Tanaka, Jiro; Suzuki, Toshihiko; Mimuro, Hitomi; Sasakawa, Chihiro

    2003-06-01

    Genetic and functional studies have indicated that the type IV secretion system (TFSS) of Helicobacter pylori forms a secretion complex in the cell envelope that protrudes towards the outside in order to inject CagA protein into gastric epithelial cells. However, the proposed structural model is based on partial amino acid homology with the components of the Agrobacterium tumefaciens TFSS. Therefore, we undertook the identification of the structural features of the TFSS exposed on the surface of H. pylori and found that filamentous structures present on the bacterial surface are related to the secretion apparatus. Using immunofluorescence microscopy with antibodies directed to tyrosine-phosphorylated CagA (pY-CagA) and Hp0532 (VirB7) in the infection assay, pY-CagA signals were detected just below the host cell-attached bacteria, where Hp0532 (VirB7) signals were detected as co-localized, suggesting that the CagA injected into the host cell through the TFSS apparatus is still mostly confined to the areas just below the attached bacteria after being phosphorylated. Furthermore, the filamentous structures on bacterium were found to be associated with Hp0532 (VirB7) or Hp0528 (VirB9), the major components of TFSS, by immunogold electron microscopy. These results strongly suggest that the H. pylori TFSS apparatus is a filamentous macromolecular structure protruding from the bacterial envelope.

  11. Structure of the type IVa major pilin from the electrically conductive bacterial nanowires of Geobacter sulfurreducens.

    Science.gov (United States)

    Reardon, Patrick N; Mueller, Karl T

    2013-10-11

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Reardon, Patrick N.; Mueller, Karl T.

    2013-10-11

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

  13. Structural mechanism of C-type inactivation in K[superscript +] channels

    Energy Technology Data Exchange (ETDEWEB)

    Cuello, Luis G.; Jogini, Vishwanath; Cortes, D. Marien; Perozo, Eduardo (UC)

    2010-08-30

    Interconversion between conductive and non-conductive forms of the K{sup +} channel selectivity filter underlies a variety of gating events, from flicker transitions (at the microsecond timescale) to C-type inactivation (millisecond to second timescale). Here we report the crystal structure of the Streptomyces lividans K{sup +} channel KcsA in its open-inactivated conformation and investigate the mechanism of C-type inactivation gating at the selectivity filter from channels 'trapped' in a series of partially open conformations. Five conformer classes were identified with openings ranging from 12 {angstrom} in closed KcsA (C{alpha}-C{alpha} distances at Thr112) to 32 {angstrom} when fully open. They revealed a remarkable correlation between the degree of gate opening and the conformation and ion occupancy of the selectivity filter. We show that a gradual filter backbone reorientation leads first to a loss of the S2 ion binding site and a subsequent loss of the S3 binding site, presumably abrogating ion conduction. These structures indicate a molecular basis for C-type inactivation in K{sup +} channels.

  14. Structure and function of the adhesive type IV pilus of Sulfolobus acidocaldarius.

    Science.gov (United States)

    Henche, Anna-Lena; Ghosh, Abhrajyoti; Yu, Xiong; Jeske, Torsten; Egelman, Edward; Albers, Sonja-Verena

    2012-12-01

    Archaea display a variety of type IV pili on their surface and employ them in different physiological functions. In the crenarchaeon Sulfolobus acidocaldarius the most abundant surface structure is the aap pilus (archaeal adhesive pilus). The construction of in frame deletions of the aap genes revealed that all the five genes (aapA, aapX, aapE, aapF, aapB) are indispensible for assembly of the pilus and an impact on surface motility and biofilm formation was observed. Our analyses revealed that there exists a regulatory cross-talk between the expression of aap genes and archaella (formerly archaeal flagella) genes during different growth phases. The structure of the aap pilus is entirely different from the known bacterial type IV pili as well as other archaeal type IV pili. An aap pilus displayed 3 stranded helices where there is a rotation per subunit of ∼138° and a rise per subunit of ∼5.7 Å. The filaments have a diameter of ∼110 Å and the resolution was judged to be ∼9 Å. We concluded that small changes in sequence might be amplified by large changes in higher-order packing. Our finding of an extraordinary stability of aap pili possibly represents an adaptation to harsh environments that S. acidocaldarius encounters.

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

    Science.gov (United States)

    Nishio, Ikuko; Chujo, Masami

    2017-03-01

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

  16. Spectral Structures and Their Generation Mechanisms for Solar Radio Type-I Bursts

    CERN Document Server

    Iwai, Kazumasa; Masuda, Satoshi; Tsuchiya, Fuminori; Morioka, Akira; Misawa, Hiroaki

    2014-01-01

    The fine spectral structures of solar radio type-I bursts were observed by the solar radio telescope AMATERAS. The spectral characteristics, such as the peak flux, duration, and bandwidth, of the individual burst elements were satisfactorily detected by the highly resolved spectral data of AMATEAS with the burst detection algorithm that is improved in this study. The peak flux of the type-I bursts followed a power-law distribution with a spectral index of 2.9-3.3, whereas their duration and bandwidth were distributed more exponentially. There were almost no correlations between the peak flux, duration, and bandwidth. That means there were no similarity shapes in the burst spectral structures. We defined the growth rate of a burst as the ratio between its peak flux and duration. There was a strong correlation between the growth rate and peak flux. These results suggest that the free energy of type-I bursts that is originally generated by non-thermal electrons is modulated in the subsequent stages of the genera...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-01

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

  18. Optimal arrangement of viscoelastic dampers for seismic control of adjacent shear-type structures

    Institute of Scientific and Technical Information of China (English)

    Xiao HUANG; Hong-ping ZHU

    2013-01-01

    The optimal arrangement of viscoelastic dampers (VEDs) used to link two adjacent shear-type structures under seismic excitation was investigated.A two-step optimal design method is proposed.First,optimal parameter expressions of the Kelvin model are used to calculate the optimal stiffness and damping coefficient of the VEDs.Then,using the two-step optimal design method,taking the quadratic performance index as the optimization objective,the optimal arrangement of the dampers is determined.General rules about the optimal arrangement of the VEDs were obtained.The results show that the placement of only one damper between two adjacent shear-type structures should be avoided; if more than one damper is used,they should be distributed on the top and lower floors of the structures.Optimization of the number of dampers had little effect on response reduction.The most important factor was the optimization of the placement of the dampers.Through comparative study,for buildings of equal and unequal heights,the optimal parameters of dampers from parametric studies were shown to match the theoretical results for different numbers and placements of dampers.The level of response reduction was shown to be sensitive to the damping coefficient of the dampers.

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

    Science.gov (United States)

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

    2003-01-01

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

  20. From Proteomics to Structural Studies of Cytosolic/Mitochondrial-Type Thioredoxin Systems in Barley Seeds

    Institute of Scientific and Technical Information of China (English)

    Azar Shahpiri; Birte Svensson; Christine Finnie

    2009-01-01

    Thioredoxins (Trx) are ubiquitous proteins that participate in thiol disulfide reactions via two active site cysteine residues,allowing Trx to reduce disulfide bonds in target proteins.Recent progress in proteome analysis has resulted in identification of a wide range of potential target proteins for Trx,indicating that Trx plays a key role in several aspects of cell metabolism.In contrast to other organisms,plants contain multiple forms of Trx that are classified based on their primary structures and sub-cellular localization.The reduction of cytosolic and mitochondrial types of Trx is dependenl on NADPH and catalyzed by NADPH-dependent thioredoxin reductase (NTR).In barley,two isoforms each of Trx and NTR have been identified and investigated using proteomics,gene expression,and structural studies.This review outlines the diverse roles suggested for cytosolic/mitochondrial-type Trx systems in cereal seeds and summarizes the current knowl-edge of the barley system including recent data on function,regulation,interactions,and structure.Directions for future research are discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-15

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

  2. Fluid Flow through Porous Sandstone with Overprinting and Intersecting Geological Structures of Various Types

    Science.gov (United States)

    Zhou, X.; Karimi-Fard, M.; Durlofsky, L.; Aydin, A.

    2010-12-01

    Impact of a wide variety of structural heterogeneities on fluid flow in an aeolian sandstone in the Valley of Fire State Park (NV), such as (1) dilatant fractures (joints), (2) shear fractures (faults), and (3) contraction/compaction structures (compaction bands), are considered. Each type of these structures has its own geometry, spacing, distribution, connectivity, and hydraulic properties, which either enhance or impede subsurface fluid flow. Permeability of these structures may, on average, be a few orders of magnitude higher or lower than those of the corresponding matrix rocks. In recent years, the influence of a single type of these heterogeneities on fluid flow has been studied individually, such as joints, compaction bands or faults. However, as different types of geological structures are commonly present together in the same rock volume, their combined effect requires a more detailed assessment. In this study, fluid flow simulations are performed using a special finite-volume discretization technique that was developed by Karimi-Fard et al. (2004; 2006). Using this approach, thin features such as fractures and compaction bands are represented as linear elements in unstructured 2D models and as planar elements in 3D models, which significantly reduces the total number of cells and simplifies grid generation. The cell geometric information and the cell-to-cell transmissibility obtained from this discretization technique are input to Stanford’s General Purpose Research Simulator (GPRS) for fluid flow simulation. To account for the effects of the various geological structures on subsurface flow, we perform permeability upscaling over regions corresponding to large-scale simulation grid blocks in order to obtain equivalent permeability components in two principal directions. We will focus on the following problems: (1) compaction bands of multisets; (2) compartmentalization of compaction bands of high-angle, low-angle and horizontal; (3) joints overprinting

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

    Science.gov (United States)

    Khim, Honggeun; Yi, Sukyoung K.

    2017-09-01

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

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    -structured communities. Like other types of trait-mediated competition, all four types of interference competition can induce disruptive selection and thus promote initial diversification. Even though foraging interference and reproductive interference are more potent in promoting initial diversification, they catalyze...... the formation of diverse communities with complex trophic structure only at high levels of interference intensity. By contrast, survival interference does so already at intermediate levels, while reproductive interference can only support relatively smaller communities with simpler trophic structure. Taken...

  5. Morphological classification and structural parameters for early-type galaxies in the Coma cluster

    CERN Document Server

    Andreon, S; Michard, R; Nieto, J L; Poulain, P

    1995-01-01

    We present the results of an isophotal shape analysis of three samples of galaxies in the Coma cluster. Quantitative morphology, together with structural and photometric parameters, is given for each galaxy. Special emphasis has been placed on the detailed classification of early-type galaxies. The three samples are: i) a sample of 97 early-type galaxies brighter than m_B = 17.00 falling within one degree from the center of the Coma cluster; these galaxies were observed with CCD cameras, mostly in good to excellent resolution conditions; ii) a magnitude complete sample of 107 galaxies of all morphological types down to m_B = 17.00 falling in a circular region of 50 arcmin diameter, slightly offcentered to the North-West of the cluster center; the images for this and the next sample come from digitized photographic plates; iii) a complete comparison sample of 26 galaxies of all morphological types down to m_R = 16.05 (or m_B \\simeq 17.5), also in a region of 50 arcmin diameter, but centered 2.6 degrees West of...

  6. Mechanical adaptability of the Bouligand-type structure in natural dermal armour

    Science.gov (United States)

    Zimmermann, Elizabeth A.; Gludovatz, Bernd; Schaible, Eric; Dave, Neil K. N.; Yang, Wen; Meyers, Marc A.; Ritchie, Robert O.

    2013-10-01

    Arapaima gigas, a fresh water fish found in the Amazon Basin, resist predation by piranhas through the strength and toughness of their scales, which act as natural dermal armour. Arapaima scales consist of a hard, mineralized outer shell surrounding a more ductile core. This core region is composed of aligned mineralized collagen fibrils arranged in distinct lamellae. Here we show how the Bouligand-type (twisted plywood) arrangement of collagen fibril lamellae has a key role in developing their unique protective properties, by using in situ synchrotron small-angle X-ray scattering during mechanical tensile tests to observe deformation mechanisms in the fibrils. Specifically, the Bouligand-type structure allows the lamellae to reorient in response to the loading environment; remarkably, most lamellae reorient towards the tensile axis and deform in tension through stretching/sliding mechanisms, whereas other lamellae sympathetically rotate away from the tensile axis and compress, thereby enhancing the scale’s ductility and toughness to prevent fracture.

  7. Optimal design of a spectral readout type planar waveguide-mode sensor with a monolithic structure.

    Science.gov (United States)

    Wang, Xiaomin; Fujimaki, Makoto; Kato, Takafumi; Nomura, Ken-Ichi; Awazu, Koichi; Ohki, Yoshimichi

    2011-10-10

    Optical planar waveguide-mode sensor is a promising candidate for highly sensitive biosensing techniques in fields such as protein adsorption, receptor-ligand interaction and surface bacteria adhesion. To make the waveguide-mode sensor system more realistic, a spectral readout type waveguide sensor is proposed to take advantage of its high speed, compactness and low cost. Based on our previously proposed monolithic waveguide-mode sensor composed of a SiO2 waveguide layer and a single crystalline Si layer [1], the mechanism for achieving high sensitivity is revealed by numerical simulations. The optimal achievable sensitivities for a series of waveguide structures are summarized in a contour map, and they are found to be better than those of previously reported angle-scan type waveguide sensors.

  8. Local equivalent welding element to predict the welding deformations of plate-type structures

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Considering the Heat Affected Zone (HAZ) of welding joint, the residual strain be-haviors of material under constraint and temperature circulation, as well as the activating mechanism of welding process, this paper addresses a new type welding element for numerical simulation of welding deformation, which is called the LEWE (the local equivalent welding element). This element can describe the basic char-acteristics of welded seam: the local position points of inherent strain, the equiva-lent size, the bending radius (or bending angle) from inherent strain, etc. It could be used to predict the welding deformation of plate-type structure. The comparisons between the computed deflection of welded plate and its experiment measurement are present. The results showed that the LEWE possesses a potential to simulate the deformation of welding process high-efficiently and precisely.

  9. Formation of Device Structures Spin-valve Type Based on Co and Cu

    Directory of Open Access Journals (Sweden)

    I.V. Cheshko

    2016-10-01

    Full Text Available The study results of structural-phase state and magnetoresistive properties of spin-valve type nano-film based on Co and Cu are shown in this work. It is found that in these systems during the preparation and annealing at temperatures Tann  700 and 900 K solid solutions of Co atoms in Cu matrix are formed. Was shown that the spin-valve type film system Co (5/Cu(x/Co(20/S expedient modified using multilayers [Co/Cu]n instead one of the magnetic Co layer. This modification increases the magnetoresistance values up to 0,3 ÷ 0,5 %, increases the switching speed from one magnetic state to another and thermal stability of nanosystems to temperature 700 K. Although magnetic sensitivity decreases to a value SB  (0,1 ÷ 0 2  10 – 2 % / mT.

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

    KAUST Repository

    Hayakawa, Shiho

    2015-03-03

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

  11. The structure of a tunicate C-type lectin from Polyandrocarpa misakiensis complexed with D -galactose.

    Science.gov (United States)

    Poget, S F; Legge, G B; Proctor, M R; Butler, P J; Bycroft, M; Williams, R L

    1999-07-23

    C-type lectins are calcium-dependent carbohydrate-recognising proteins. Isothermal titration calorimetry of the C-type Polyandrocarpa lectin (TC14) from the tunicate Polyandrocarpa misakiensis revealed the presence of a single calcium atom per monomer with a dissociation constant of 2.6 microM, and confirmed the specificity of TC14 for D -galactose and related monosaccharides. We have determined the 2.2 A X-ray crystal structure of Polyandrocarpa lectin complexed with D -galactose. Analytical ultracentrifugation revealed that TC14 behaves as a dimer in solution. This is reflected by the presence of two molecules in the asymmetric unit with the dimeric interface formed by antiparallel pairing of the two N-terminal beta-strands and hydrophobic interactions. TC14 adopts a typical C-type lectin fold with differences in structure from other C-type lectins mainly in the diverse loop regions and in the second alpha-helix, which is involved in the formation of the dimeric interface. The D -galactose is bound through coordination of the 3 and 4-hydroxyl oxygen atoms with a bound calcium atom. Additional hydrogen bonds are formed directly between serine, aspartate and glutamate side-chains of the protein and the sugar 3 and 4-hydroxyl groups. Comparison of the galactose binding by TC14 with the mannose binding by rat mannose-binding protein reveals how monosaccharide specificity is achieved in this lectin. A tryptophan side-chain close to the binding site and the distribution of hydrogen-bond acceptors and donors around the 3 and 4-hydroxyl groups of the sugar are essential determinants of specificity. These elements are, however, arranged in a very different way than in an engineered galactose-specific mutant of MBPA. Possible biological functions can more easily be understood from the fact that TC14 is a dimer under physiological conditions. Copyright 1999 Academic Press.

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

    Science.gov (United States)

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

    2009-08-12

    The objectives of this study were to use Fourier transform infrared microspectroscopy (FTIRM) to determine structural makeup (features) of cereal grain endosperm tissue and to reveal and identify differences in protein and carbohydrate structural makeup between different cereal types (corn vs barley) and between different varieties within a grain (barley CDC Bold, CDC Dolly, Harrington, and Valier). Another objective was to investigate how these structural features relate to rumen degradation kinetics. The items assessed included (1) structural differences in protein amide I to nonstructural carbohydrate (NSC, starch) intensity and ratio within cellular dimensions; (2) molecular structural differences in the secondary structure profile of protein, alpha-helix, beta-sheet, and their ratio; (3) structural differences in NSC to amide I ratio profile. From the results, it was observed that (1) comparison between grain types [corn (cv. Pioneer 39P78) vs barley (cv. Harrington)] showed significant differences in structural makeup in terms of NSC, amide I to NSC ratio, and rumen degradation kinetics (degradation ratio, effective degradability of dry matter, protein and NSC) (P degradation kinetics (effective degradability of dry matter, protein, and NSC) (P degradation kinetics in terms of the degradation rate (R = 0.91, P = 0.086) and effective degradability of dry matter (R = 0.93, P = 0.071). The results suggest that with the FTIRM technique, the structural makeup differences between cereal types and between different varieties within a type of grain could be revealed. These structural makeup differences were related to the rate and extent of rumen degradation.

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

    DEFF Research Database (Denmark)

    Schneider, Ronald; Thöns, Sebastian; Rogge, Andreas

    2017-01-01

    and risk. We intend to adopt this approach to optimize inspection, monitoring and repair activities for offshore wind park support structures. As a first step, we simulate – in analogy to an offshore wind park – the service life performance of an inspected group of jacket-type frames. The performance...... failure probability conditional on simulated inspection and repair histories, and evaluates the associated costs and risk. The expected total service life costs and risk for a strategy are finally determined using Monte Carlo simulation. The optimal strategy minimizes the expected total service life costs...

  14. Structure Design and Optimization of a New Type of Subsea Pipeline Connector

    Institute of Scientific and Technical Information of China (English)

    XJaoming Hu; Liquan Wang; Yong Liu; Rubo Ge; Lei Tan; Chuangye Fu; Zongliang Wei

    2012-01-01

    The basic configuration of a new type of subsea pipeline connector was proposed based on the press-fitting principle,and a parametric fmite element model was created using APDL language in ANSYS.Combining the finite element model and optimization technology,the dimension optimization aiming at obtaining the minimum loading force and the optimum sealing performance was designed by the zero order optimization method.Experiments of the optimized connector were canied out.The results indicate that the optimum structural design significantly improved the indicators of the minimum loading force and sealing performance of the connector.

  15. Reducing democratic type II supergravity on SU(3) x SU(3) structures

    CERN Document Server

    Cassani, Davide

    2008-01-01

    Type II supergravity on backgrounds admitting SU(3) x SU(3) structure and general fluxes is considered. Using the generalized geometry formalism, we study dimensional reductions leading to N=2 gauged supergravity in four dimensions, possibly with tensor multiplets. In particular, a geometric formula for the full N=2 scalar potential is given. Then we implement a truncation ansatz, and derive the complete N=2 bosonic action. While the NSNS contribution is obtained via a direct dimensional reduction, the contribution of the RR sector is computed starting from the democratic formulation and demanding consistency with the reduced equations of motion.

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

    KAUST Repository

    Ershadi, A.

    2015-04-12

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

  17. On the flat spacetime Galileons and the Born-Infeld type structures

    CERN Document Server

    Campuzano, Cuauhtemoc; Cruz, Miguel; Rojas, Efrain

    2015-01-01

    We show how the flat spacetime Galileon field theories in arbitrary dimensions can be obtained through a Born-Infeld type structure. This construction involves a brane metric and non-linear combinations of derivatives of a scalar field. Our setup gives rise to some Galileon tensors and vectors useful for the variational analysis which are related to the momentum density of the probe Lovelock branes floating in a $N$-dimensional flat bulk. We find further that the Noether currents associated to these Galileon theories may be written in terms of such tensors.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-17

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

  19. Communications: A systematic method for locating transition structures of A+B-->X type reactions

    Science.gov (United States)

    Maeda, Satoshi; Morokuma, Keiji

    2010-06-01

    Search for transition structures (TSs) as first-order saddles is one of the most important tasks in theoretical study of chemical reaction. Although automated search has been established either by starting from a local minimum (MIN) or by connecting two MINs, there is no systematic method which can locate TSs of A+B→X(+Y) type reactions starting from separated reactants. We propose such an approach for the first time; it was demonstrated to work very well in the SN2, Diels-Alder, and Wittig reactions.

  20. Positive convolution structure for a class of Heckman-Opdam hypergeometric functions of type BC

    CERN Document Server

    Rösler, Margit

    2009-01-01

    In this paper, we derive explicit product formulas and positive convolution structures for three continuous classes of Heckman-Opdam hypergeometric functions of type $BC$. For specific discrete series of multiplicities these hypergeometric functions occur as the spherical functions of non-compact Grassmann manifolds $G/K$ over one of the (skew) fields $\\mathbb F= \\mathbb R, \\mathbb C, \\mathbb H.$ We write the product formula of these spherical functions in an explicit form which allows analytic continuation with respect to the parameters. In each of the three cases, we obtain a series of hypergroup algebras which include the commutative convolution algebras of $K$-biinvariant functions on $G$.

  1. New transition metal oxide fluorides with ReO{sub 3}-type structure

    Energy Technology Data Exchange (ETDEWEB)

    Nakhal, Suliman; Lerch, Martin [Technische Universitaet Berlin (Germany). Inst. fuer Chemie

    2016-08-01

    The new niobium oxide fluorides MNbO{sub 2}F{sub 4} [M = (Cr, Fe)], CrNb{sub 2}O{sub 4}F{sub 5}, and Fe{sub 2}Nb{sub 3}O{sub 6}F{sub 9} were prepared by treatment of chromium or iron nitrate with Nb-containing hydrofluoric acid solutions. Crystal structures were investigated by means of X-ray powder diffraction. All new compounds can be structurally refined in the cubic ReO{sub 3}-type. The iron niobium oxide fluorides are reddish orange, and chromium containing phases exhibit a light green color. The niobium atoms are in the highest formal oxidation state.

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

    Energy Technology Data Exchange (ETDEWEB)

    Benmachiche, I.

    2006-07-15

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

  3. New intermetallic compounds with the ErCuCd{sub 2} type of structure

    Energy Technology Data Exchange (ETDEWEB)

    Zelinska, O.Ya.; Solokha, P.G.; Pavlyuk, V.V

    2004-03-24

    The crystal structure of new RTZn{sub 2} intermetallic compounds (R=La, Ce, Tb; T=Co, Cu) was determined. The X-ray diffraction data showed that these compounds are isostructural to the new ternary compound ErCuCd{sub 2}, which was found to crystallize with a superstructure of the ErCd{sub 3} structure type (space group Cmcm, Pearson code oS16, a=0.7097(1) nm, b=1.0659(3) nm, c=0.4471(1) nm, V=0.3382(2) nm{sup 3}, Z=4). The obtained reliability factors are R{sub F}=0.0240 and R{sub w}=0.1127 for 235 unique reflections (vertical barF{sub 0} vertical bar>4.00{sigma}|F{sub 0}|)

  4. Toothpaste lava: Characteristics and origin of a lava structural type transitional between pahoehoe and aa

    Science.gov (United States)

    Rowland, Scott K.; Walker, George P. L.

    1987-08-01

    Toothpaste lava, an important basalt structural type which illustrates the transition from pahoehoe to aa, is particularly well displayed on the 1960 Kapoho lava of Kilauea Volcano. Its transitional features stem from a viscosity higher than that of pahoehoe and a rate of flow slower than that of aa. Viscosity can be quantified by the limited settling of olivine phenocrysts and rate of flow by field observations related to the low-angle slope on which the lava flowed. Much can be learned about the viscosity, rheologic condition, and flow velocity of lavas long after solidification by analyses of their structural characteristics, and it is possible to make at least a semiquantitative assessment of the numerical values of these parameters.

  5. Material and Geometric Nonlinear Analysis of Functionally Graded Plate-Shell Type Structures

    Science.gov (United States)

    Moita, J. S.; Araújo, A. L.; Mota Soares, C. M.; Mota Soares, C. A.; Herskovits, J.

    2016-08-01

    A nonlinear formulation for general Functionally Graded Material plate-shell type structures is presented. The formulation accounts for geometric and material nonlinear behaviour of these structures. Using the Newton-Raphson incremental-iterative method, the incremental equilibrium path is obtained, and in case of snap-through occurrence the automatic arc-length method is used. This simple and fast element model is a non-conforming triangular flat plate/shell element with 24 degrees of freedom for the generalized displacements. It is benchmarked in the solution of some illustrative plate- shell examples and the results are presented and discussed with numerical alternative models. Benchmark tests with material and geometrically nonlinear behaviour are also proposed.

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

    DEFF Research Database (Denmark)

    Julenius, Karin; Mølgaard, Anne; Gupta, Ramneek

    2005-01-01

    than a nonglycosylated one. The Protein Data Bank was analyzed for structural information, and 12 glycosylated structures were obtained. All positive sites were found in coil or turn regions. A method for predicting the location for mucin-type glycosylation sites was trained using a neural network...... approach. The best overall network used as input amino acid composition, averaged surface accessibility predictions together with substitution matrix profile encoding of the sequence. To improve prediction on isolated (single) sites, networks were trained on isolated sites only. The final method combines...... predictions from the best overall network and the best isolated site network; this prediction method correctly predicted 76% of the glycosylated residues and 93% of the nonglycosylated residues. NetOGlyc 3.1 can predict sites for completely new proteins without losing its performance. The fact that the sites...

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

    CERN Document Server

    Kanchana, V; Rajagopalan, M

    2003-01-01

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

  8. Electronic structure and optical properties of a new type of semiconductor material:graphene monoxide

    Institute of Scientific and Technical Information of China (English)

    Yang Gui; Zhang Yufeng; Yan Xunwang

    2013-01-01

    The electronic and optical properties of graphene monoxide,a new type of semiconductor material,are theoretically studied by first-principles density functional theory.The calculated band structure shows that graphene monoxide is a semiconductor with a direct band gap of 0.95 eV.The density of states of graphene monoxide and the partial density of states for C and O are given to understand the electronic structure.In addition,we calculate the optical properties of graphene monoxide,including the complex dielectric function,absorption coefficient,complex refractive index,loss-function,reflectivity and conductivity.These results provide a physical basis for potential application in optoelectronic devices.

  9. Electronic Structures of PbWO4 Crystals Containing F-Type Colour Centres

    Institute of Scientific and Technical Information of China (English)

    YI Zhi-Jun; LIU Ting-Yu; ZHANG Qi-Ren; SUN Yuan-Yuan

    2005-01-01

    @@ Electronic structures of PbWO4 crystals containing F-type colour centres with the lattice structure optimized are studied within the framework of the fully relativistic selF-consistent Dirac-Slater theory, using a numerically discrete variational (DV-Xα) method. The calculated results show that F and F+ centres have donor energy levels in the forbidden bands. Their optical transition energies are 1.84 eV and 2.21 eV, respectively, which correspond to the 680nm and 550nm absorption bands. It is predicted that the 680nm and 550nm absorption banas originate from the F and F+ centres in PbWO4 crystals.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  11. Sleep paralysis episode frequency and number, types, and structure of associated hallucinations.

    Science.gov (United States)

    Cheyne, J A

    2005-09-01

    Sleep paralysis (SP) episodes are often accompanied by vivid hallucinoid experiences that have been found to fall into three major categories thought to be organized according to intrinsic rapid eye movement (REM) processes. Prior research has, however, combined data for individuals with varying degrees of experience with SP episodes, rendering interpretations of the source of this structure ambiguous. The present study of 5799 current SP experients compares the nature and structure of the hallucinations of novice SP experients with those reporting varying numbers of episodes. Both qualitative and quantitative differences were found in reported hallucinations as a function of episode frequency, although the underlying three-factor structure of the hallucinoid experiences was highly similar for all groups. Novice experients' reports were, however, characterized by clearer differentiation of factors, likely because of a tendency of experienced SP experients to conflate experiences across episodes. Age and age of onset of SP episodes were associated with differences in the variety and types of hallucinations but not their underlying structure. Earlier onset of SP episodes was also associated with more frequent episodes. The results are consistent with the hypothesis that the basic form and patterning of hallucinatory experiences is a result of intrinsic processes, independent of prior experience, likely associated with underlying REM neurophysiology.

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

    Science.gov (United States)

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

    2017-01-01

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

  13. Structure and transport properties of ethylcellulose membranes with different types and granulation of magnetic powder

    Science.gov (United States)

    Krasowska, Monika; Strzelewicz, Anna; Rybak, Aleksandra; Dudek, Gabriela; Cieśla, Michał

    2016-06-01

    Structure and transport properties of ethylcellulose membranes with dispersed magnetic powder were investigated. The study mainly focused on diffusion, which is one of the transport mechanisms. The transport properties depend on many parameters like: polymeric matrix used, type of powder, its amount and granulation. The structure of the pattern formed by magnetic particles in the membrane matrix was studied. Description of the system was based on the phenomenological and molecular (random walk on a fractal lattice) approaches. Two parameters were calculated: the fractal dimension of random walk dw, and the fractal dimension of membrane structure df. The knowledge of both parameters made it possible to use the generalized equation of diffusion on the fractal structure obtained by Metzler et al. The research was carried out to determine the influence of magnetic powder granulation on the transport properties. The results showed that the random walk within the membranes of the smallest magnetic powder granulation was of the most subdiffusive character. Detailed investigation and quantitative description of gas transport through the membranes enables designing the membranes to be used in air oxygen enrichment.

  14. Fine-scale phylogeographic structure of Borrelia lusitaniae revealed by multilocus sequence typing.

    Directory of Open Access Journals (Sweden)

    Liliana R Vitorino

    Full Text Available Borrelia lusitaniae is an Old World species of the Lyme borreliosis (LB group of tick-borne spirochetes and prevails mainly in countries around the Mediterranean Basin. Lizards of the family Lacertidae have been identified as reservoir hosts of B. lusitaniae. These reptiles are highly structured geographically, indicating limited migration. In order to examine whether host geographic structure shapes the evolution and epidemiology of B. lusitaniae, we analyzed the phylogeographic population structure of this tick-borne bacterium using a recently developed multilocus sequence typing (MLST scheme based on chromosomal housekeeping genes. A total of 2,099 questing nymphal and adult Ixodes ricinus ticks were collected in two climatically different regions of Portugal, being approximately 130 km apart. All ticks were screened for spirochetes by direct PCR. Attempts to isolate strains yielded 16 cultures of B. lusitaniae in total. Uncontaminated cultures as well as infected ticks were included in this study. The results using MLST show that the regional B. lusitaniae populations constitute genetically distinct populations. In contrast, no clear phylogeographic signals were detected in sequences of the commonly used molecular markers ospA and ospC. The pronounced population structure of B. lusitaniae over a short geographic distance as captured by MLST of the housekeeping genes suggests that the migration rates of B. lusitaniae are rather low, most likely because the distribution of mediterranean lizard populations is highly parapatric. The study underlines the importance of vertebrate hosts in the geographic spread of tick-borne microparasites.

  15. Fine-scale phylogeographic structure of Borrelia lusitaniae revealed by multilocus sequence typing.

    Science.gov (United States)

    Vitorino, Liliana R; Margos, Gabriele; Feil, Edward J; Collares-Pereira, Margarida; Zé-Zé, Libia; Kurtenbach, Klaus

    2008-01-01

    Borrelia lusitaniae is an Old World species of the Lyme borreliosis (LB) group of tick-borne spirochetes and prevails mainly in countries around the Mediterranean Basin. Lizards of the family Lacertidae have been identified as reservoir hosts of B. lusitaniae. These reptiles are highly structured geographically, indicating limited migration. In order to examine whether host geographic structure shapes the evolution and epidemiology of B. lusitaniae, we analyzed the phylogeographic population structure of this tick-borne bacterium using a recently developed multilocus sequence typing (MLST) scheme based on chromosomal housekeeping genes. A total of 2,099 questing nymphal and adult Ixodes ricinus ticks were collected in two climatically different regions of Portugal, being approximately 130 km apart. All ticks were screened for spirochetes by direct PCR. Attempts to isolate strains yielded 16 cultures of B. lusitaniae in total. Uncontaminated cultures as well as infected ticks were included in this study. The results using MLST show that the regional B. lusitaniae populations constitute genetically distinct populations. In contrast, no clear phylogeographic signals were detected in sequences of the commonly used molecular markers ospA and ospC. The pronounced population structure of B. lusitaniae over a short geographic distance as captured by MLST of the housekeeping genes suggests that the migration rates of B. lusitaniae are rather low, most likely because the distribution of mediterranean lizard populations is highly parapatric. The study underlines the importance of vertebrate hosts in the geographic spread of tick-borne microparasites.

  16. Development of Processable PMR-Type Polymides with Star-Branched Structures

    Science.gov (United States)

    Nguyen, Baochau N.; Eby, R. K.; Meador, Michael A.

    1999-01-01

    In the last two decades, high temperature polyimide matrix composites have found broad applications in aerospace structural components, due to their high specific modulus and high specific strength. As matrix resins, aromatic polyimides exhibit exceptional thermal stability and mechanical properties. However, their rodlike structures often result in poor solubility in most common organic solvents, as well as high melt temperature and melt viscosity, making them difficult to process. To overcome this difficulty, flexible linkages including O, SO2 or CH2 non coplanar biphenyl moieties, bulky lateral substituents, and crankshaft structures are often incorporated into the polymer backbones. Addition-curing of low molecular weight polyimides (resins) is another approach to improve processability. One of the most successfully developed materials has been PMR-15 (Polymerization of Monomer Reactants, molecular weight of 1500 g/mol), because of its good combination of thermal and mechanical properties and ease of processability. However, due to the high melt viscosity of PMR-type resins, use of more economical processing methods, such as resin transfer molding (RTM), is not possible. Recent research has focused on the incorporation of trifunctional monomers into addition-curing polyimides in an attempt to improve the processability of these polymers. The objective of this research is to use an aromatic triamine, 1,3,5 tris (4-aminophenoxy) benzene, to prepare new resin systems with starbranched structures. The glass transition temperatures (Tg's) and thermal oxidative stability TOS) of these polymers are compared to their linear counterparts and PMR-15.

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hermans Mieke CE

    2012-07-01

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

  19. Types and concentrations of metal ions affect local structure and dynamics of RNA

    Science.gov (United States)

    Wang, Jun; Xiao, Yi

    2016-10-01

    The roles that metal ions play in the structure and dynamics of RNA molecules are long-standing problems that have been studied extensively but are still not well understood. Here we show that metal ions have distributions around RNA molecules that strongly depend on the types and concentrations of the metal ions and also the electrostatic surface of the molecule. In particular, the ion distributions may not balance all the local electronegativity of the molecule. These ion distributions do not only greatly affect local structures but also lead to different local dynamics of RNA. We studied the effects of different ion solutions on the structure and dynamics of RNA by taking the pre Q1 riboswitch aptamer domain as an illustrative example and using molecular dynamics simulations. Since the local structures and dynamics of RNAs are important to their functions, our results also indicate that the selection of proper ion conditions is necessary to model them correctly, in contrast to the use of diverse ion solutions in current molecular dynamics simulations.

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

    Directory of Open Access Journals (Sweden)

    M. NORHISAM

    2015-03-01

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

  1. Synthesis, structural transformation, thermal stability, valence state, and magnetic and electronic properties of PbNiO3 with perovskite- and LiNbO3-type structures.

    Science.gov (United States)

    Inaguma, Yoshiyuki; Tanaka, Kie; Tsuchiya, Takeshi; Mori, Daisuke; Katsumata, Tetsuhiro; Ohba, Tomonori; Hiraki, Ko-ichi; Takahashi, Toshihiro; Saitoh, Hiroyuki

    2011-10-26

    We synthesized two high-pressure polymorphs PbNiO(3) with different structures, a perovskite-type and a LiNbO(3)-type structure, and investigated their formation behavior, detailed structure, structural transformation, thermal stability, valence state of cations, and magnetic and electronic properties. A perovskite-type PbNiO(3) synthesized at 800 °C under a pressure of 3 GPa crystallizes as an orthorhombic GdFeO(3)-type structure with a space group Pnma. The reaction under high pressure was monitored by an in situ energy dispersive X-ray diffraction experiment, which revealed that a perovskit-type phase was formed even at 400 °C under 3 GPa. The obtained perovskite-type phase irreversibly transforms to a LiNbO(3)-type phase with an acentric space group R3c by heat treatment at ambient pressure. The Rietveld structural refinement using synchrotron X-ray diffraction data and the XPS measurement for both the perovskite- and the LiNbO(3)-type phases reveal that both phases possess the valence state of Pb(4+)Ni(2+)O(3). Perovskite-type PbNiO(3) is the first example of the Pb(4+)M(2+)O(3) series, and the first example of the perovskite containing a tetravalent A-site cation without lone pair electrons. The magnetic susceptibility measurement shows that the perovskite- and LiNbO(3)-type PbNiO(3) undergo antiferromagnetic transition at 225 and 205 K, respectively. Both the perovskite- and LiNbO(3)-type phases exhibit semiconducting behavior.

  2. Human lymphocyte markers defined by antibodies derived from somatic cell hybrids. II. A hybridoma secreting antibody against an antigen expressed by human B and null lymphocytes.

    Science.gov (United States)

    Beckman, I G; Bradley, J; Brooks, D A; Kupa, A; McNamara, P J; Thomas, M E; Zola, H

    1980-06-01

    A hybridoma (FMC4) has been derived which secretes antibody showing selective reaction with human B lymphocytes, monocytes and some null lymphocytes. Few, if any, T lymphocytes in normal blood are stained, although stimulation of lymphocytes with PHA leads to an increase in the proportion of cells reacting with the hybridoma antibody. The antibody reacts with B and null lymphoblastoid cell lines but not with T cell lines. B chronic lymphocytic leukaemia (CLL) cells but not T-CLLs are stained and null-type acute lymphoblastic leukaemia (ALL) cells but not T-type ALL also react. Normal blood myeloid cells do not react with FMC4 supernatant whilst some myeloid leukaemias do. The expression of the antigen reacting with FMC4 supernatant suggests that FMC4 may secrete an antibody against the human equivalent of the Ia antigen.

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

    Science.gov (United States)

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

    2016-01-01

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

  4. Nuclear structure and the fate of core collapse (Type II) supernova

    Energy Technology Data Exchange (ETDEWEB)

    Gai, Moshe [LNS at Avery Point, University of Connecticut, Groton, CT 06340-6097 (United States); Wright Lab, Dept. of Physics, Yale University, New Haven, CT 06520-8124 (United States)

    2014-08-15

    For a long time Gerry Brown and his collaborator Hans Bethe considered the question of the final fate of a core collapse (Type II) supernova. Recalling ideas from nuclear structure on Kaon condensate and a soft equation of state of the dense nuclear matter they concluded that progenitor stars with mass as low as 17–18M{sub ⊙} (including supernova 1987A) could collapse to a small mass black hole with a mass just beyond 1.5M{sub ⊙}, the upper bound they derive for a neutron star. We discuss another nuclear structure effect that determines the carbon to oxygen ratio (C/O) at the end of helium burning. This ratio also determines the fate of a Type II supernova with a carbon rich progenitor star producing a neutron star and oxygen rich collapsing to a black hole. While the C/O ratio is one of the most important nuclear inputs to stellar evolution it is still not known with sufficient accuracy. We discuss future efforts to measure with gamma-beam and TPC detector of the {sup 12}C(α,γ){sup 16}O reaction that determines the C/O ratio in stellar helium burning.

  5. Generalized N=1 and N=2 structures in M-theory and type II orientifolds

    CERN Document Server

    Graña, Mariana

    2012-01-01

    We consider M-theory and type IIA reductions to four dimensions with N=2 and N=1 supersymmetry and discuss their interconnection. Our work is based on the framework of Exceptional Generalized Geometry (EGG), which extends the tangent bundle to include all symmetries in M-theory and type II string theory, covariantizing the local U-duality group E7. We describe general N=1 and N=2 reductions in terms of SU(7) and SU(6) structures on this bundle and thereby derive the effective four-dimensional N=1 and N=2 couplings, in particular we compute the Kahler and hyper-Kahler potentials as well as the triplet of Killing prepotentials (or the superpotential in the N=1 case). These structures and couplings can be described in terms of forms on an eight-dimensional tangent space where SL(8) contained in E7 acts, which might indicate a description in terms of an eight-dimensional internal space, similar to F-theory. We finally discuss an orbifold action in M-theory and its reduction to O6 orientifolds, and show how the pr...

  6. Hamiltonian Structures and Integrability for a Discrete Coupled KdV-Type Equation Hierarchy

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hai-Qiong; ZHU Zuo-Nong; ZHANG Jing-Li

    2011-01-01

    @@ Coupled Korteweg-de Vries(KdV) systems have many important physical applications.By considering a 4 × 4spectral problem,we derive a discrete coupled KdV-type equation hierarchy.Our hierarchy includes the coupled Volterra system proposed by Lou et al.(e-print arXiv:0711.0420) as the first member which is a discrete version of the coupled KdV equation.We also investigate the integrability in the Liouville sense and the multi-Hamiltonian structures for the obtained hierarchy.%Coupled Korteweg-de Vries (KdV) systems have many important physical applications.By considering a 4 × 4 spectral problem, we derive a discrete coupled KdV-type equation hierarchy.Our hierarchy includes the coupled Volterra system proposed by Lou et al.(e-print arXiv: 0711.0420) as the first member which is a discrete version of the coupled KdV equation.We also investigate the integrability in the Liouville sense and the multi-Hamiltonian structures for the obtained hierarchy.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-01

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

  8. Nuclear Structure and the Fate of Core Collapse (Type II) Supernova

    CERN Document Server

    Gai, Moshe

    2014-01-01

    For a long time Gerry Brown and his collaborator Hans Bethe considered the question of the final fate of a core collapse (Type II) supernova. Recalling ideas from nuclear structure on Kaon condensate and a soft equation of state of the dense nuclear matter they concluded that progenitor stars with mass as low a 17-18M$_\\odot$ (including supernova 1987A) could collapse to a small mass black hole with a mass just beyond 1.5M$_\\odot$, the upper bound they derive for a neutron star. We discuss another nuclear structure effect that determines the carbon to oxygen ratio (C/O) at the end of helium burning. This ratio also determines the fate of a Type II supernova with a carbon rich progenitor star producing a neutron star and oxygen rich collapsing to a black hole. While the C/O ratio is one of the most important nuclear input to stellar evolution it is still not known with sufficient accuracy. We discuss future efforts to measure with gamma-beam and TPC detector the 12C(a,g)16O reaction that determines the C/O rat...

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

    Directory of Open Access Journals (Sweden)

    Castejón, L.

    1997-12-01

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

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

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

    Directory of Open Access Journals (Sweden)

    Neelanjana Janardan

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

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

    Directory of Open Access Journals (Sweden)

    Burkhard Pleger

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

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

    Science.gov (United States)

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

    2014-01-01

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

  13. High-pressure synthesis of ferromagnetic Mn3Ge with the Cu3Au-type structure

    Science.gov (United States)

    Takizawa, H.; Yamashita, T.; Uheda, K.; Endo, T.

    2002-11-01

    A new intermetallic compound, Mn3Ge, has been synthesized by direct reaction of elemental components at 6.2 GPa and 1000°C for 30 min using a belt-type high-pressure apparatus. The compound crystallizes into a cubic structure with the space group Pm3m, namely the L12-type (Cu3Au-type) structure. The structure was refined by Rietveld analysis of the powder x-ray diffraction data and the lattice constant was determined as a = 0.380 19(3) nm. The compound shows metallic conductivity and ferromagnetism with a Curie temperature of 400 K.

  14. Recent Structural Evolution of Early-Type Galaxies: Size Growth from z=1 to z=0

    CERN Document Server

    van der Wel, Arjen; Zirm, Andrew W; Franx, Marijn; Rettura, Alessandro; Illingworth, Garth D; Ford, Holland C

    2008-01-01

    Strong size and internal density evolution of early-type galaxies between z~2 and the present has been reported by several authors. Here we analyze samples of nearby and distant (z~1) galaxies with dynamically measured masses in order to confirm the previous, model-dependent results and constrain the uncertainties that may play a role. Velocity dispersion measurements are taken from the literature for 50 morphologically selected 0.8type galaxies with typical masses 2e11 Msol. Sizes are determined with ACS imaging. We compare the distant sample with a large sample of nearby (0.04type galaxies extracted from the SDSSfor which we determine sizes, masses, and densities in a consistent manner, using simulations to quantify systematic differences between the size measurements of nearby and distant galaxies. We find a highly significant structural difference between the nearby and distant samples, regardless of sample selection effects. The implied evolution ...

  15. Development of microsatellite markers for Lachancea thermotolerans typing and population structure of wine-associated isolates.

    Science.gov (United States)

    Banilas, Georgios; Sgouros, Georgios; Nisiotou, Aspasia

    2016-12-01

    Lachancea (Kluyveromyces) thermotolerans is an important member of the grape/wine yeast community with great technological potential for the wine industry. Although several molecular marker techniques have been developed for typing different yeast species, no one has been designed so far for L. thermotolerans. Here we present a simple and efficient method based on a multilocus SSR analysis for molecular typing and genetic diversity assessment of L. thermotolerans isolates. Following whole genome screening, five polymorphic microsatellite markers were selected and tested on a panel of grape isolates from different vineyards of two geographically separated viticultural zones, Nemea and Peza, in Greece. The SSR method proved quite discriminatory as compared to tandem repeat-tRNA-PCR, a fingerprinting method for typing non-Saccharomyces yeasts. Genetic analysis based on SSR data revealed a clear structure between the populations of the two zones. Furthermore, significant differences were also detected in a number of phenotypic characters of enological interest. A positive correlation was observed between phenotypic and genotypic diversity. Taking together, present results support the microbial terroir concept in the case of L. thermotolerans in Greece, which is an important prerequisite for the exploitation of selected genotypes as fermentation starters with region-specific characters.

  16. Enhancement of carrier lifetimes in type-II quantum dot/quantum well hybrid structures

    Energy Technology Data Exchange (ETDEWEB)

    Couto, O. D. D., E-mail: odilon@ifi.unicamp.br; Almeida, P. T. de; Santos, G. E. dos; Balanta, M. A. G.; Andriolo, H. F.; Brum, J. A.; Brasil, M. J. S. P.; Iikawa, F. [Instituto de Física “Gleb Wataghin,” Universidade Estadual de Campinas, 13083-859 Campinas, São Paulo (Brazil); Liang, B. L., E-mail: bliang@cnsi.ucla.edu; Huffaker, D. L. [California NanoSystems Institute, UCLA, Los Angeles, California 90095 (United States)

    2016-08-28

    We investigate optical transitions and carrier dynamics in hybrid structures containing type-I GaAs/AlGaAs quantum wells (QWs) and type-II GaSb/AlGaAs quantum dots (QDs). We show that the optical recombination of photocreated electrons confined in the QWs with holes in the QDs and wetting layer can be modified according to the QW/QD spatial separation. In particular, for low spacer thicknesses, the QW optical emission can be suppressed due to the transference of holes from the QW to the GaSb layer, favoring the optical recombination of spatially separated carriers, which can be useful for optical memory and solar cell applications. Time-resolved photoluminescence (PL) measurements reveal non-exponential recombination dynamics. We demonstrate that the PL transients can only be quantitatively described by considering both linear and quadratic terms of the carrier density in the bimolecular recombination approximation for type-II semiconductor nanostructures. We extract long exciton lifetimes from 700 ns to 5 μs for QDs depending on the spacer layer thickness.

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

    Directory of Open Access Journals (Sweden)

    Xuhui Liu

    2015-11-01

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

  18. Assembly and stoichiometry of the core structure of the bacterial flagellar type III export gate complex.

    Science.gov (United States)

    Fukumura, Takuma; Makino, Fumiaki; Dietsche, Tobias; Kinoshita, Miki; Kato, Takayuki; Wagner, Samuel; Namba, Keiichi; Imada, Katsumi; Minamino, Tohru

    2017-08-01

    The bacterial flagellar type III export apparatus, which is required for flagellar assembly beyond the cell membranes, consists of a transmembrane export gate complex and a cytoplasmic ATPase complex. FlhA, FlhB, FliP, FliQ, and FliR form the gate complex inside the basal body MS ring, although FliO is required for efficient export gate formation in Salmonella enterica. However, it remains unknown how they form the gate complex. Here we report that FliP forms a homohexameric ring with a diameter of 10 nm. Alanine substitutions of conserved Phe-137, Phe-150, and Glu-178 residues in the periplasmic domain of FliP (FliPP) inhibited FliP6 ring formation, suppressing flagellar protein export. FliO formed a 5-nm ring structure with 3 clamp-like structures that bind to the FliP6 ring. The crystal structure of FliPP derived from Thermotoga maritia, and structure-based photo-crosslinking experiments revealed that Phe-150 and Ser-156 of FliPP are involved in the FliP-FliP interactions and that Phe-150, Arg-152, Ser-156, and Pro-158 are responsible for the FliP-FliO interactions. Overexpression of FliP restored motility of a ∆fliO mutant to the wild-type level, suggesting that the FliP6 ring is a functional unit in the export gate complex and that FliO is not part of the final gate structure. Copurification assays revealed that FlhA, FlhB, FliQ, and FliR are associated with the FliO/FliP complex. We propose that the assembly of the export gate complex begins with FliP6 ring formation with the help of the FliO scaffold, followed by FliQ, FliR, and FlhB and finally FlhA during MS ring formation.

  19. Crystal structure of the type IV secretion system component CagX from Helicobacter pylori

    Science.gov (United States)

    Zhang, Jin; Fan, Fei; Zhao, Yanhe; Sun, Lifang; Liu, Yadan; Wu, Yunkun

    2017-01-01

    Helicobacter pylori, a Gram-negative bacterial pathogen prevalent in the human population, is the causative agent of severe gastric diseases. An H. pylori type IV secretion (T4S) system encoded by the cytotoxin-associated gene pathogenicity island (cagPAI) is responsible for communication with host cells. As a component of the cagPAI T4S system core complex, CagX plays an important role in virulence-protein translocation into the host cells. In this work, the crystal structure of the C-terminal domain of CagX (CagXct), which is a homologue of the VirB9 protein from the VirB/D4 T4S system, is presented. CagXct is only the second three-dimensional structure to be elucidated of a VirB9-like protein. Another homologue, TraO, which is encoded on the Escherichia coli conjugative plasmid pKM101, shares only 19% sequence identity with CagXct; however, there is a remarkable similarity in tertiary structure between these two β-sandwich protein domains. Most of the residues that are conserved between CagXct and TraO are located within the protein core and appear to be responsible for the preservation of this domain fold. The studies presented here will contribute to our understanding of different bacterial T4S systems. PMID:28291753

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

    Science.gov (United States)

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

    2012-10-24

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

  1. Dystrophin and utrophin influence fiber type composition and post-synaptic membrane structure.

    Science.gov (United States)

    Rafael, J A; Townsend, E R; Squire, S E; Potter, A C; Chamberlain, J S; Davies, K E

    2000-05-22

    The X-linked muscle wasting disease Duchenne muscular dystrophy is caused by the lack of dystrophin in muscle. Protein structure predictions, patient mutations, in vitro binding studies and transgenic and knockout mice suggest that dystrophin plays a mechanical role in skeletal muscle, linking the subsarcolemmal cytoskeleton with the extracellular matrix through its direct interaction with the dystrophin-associated protein complex (DAPC). Although a signaling role for dystrophin has been postulated, definitive data have been lacking. To identify potential non-mechanical roles of dystrophin, we tested the ability of various truncated dystrophin transgenes to prevent any of the skeletal muscle abnormalities associated with the double knockout mouse deficient for both dystrophin and the dystrophin-related protein utrophin. We show that restoration of the DAPC with Dp71 does not prevent the structural abnormalities of the post-synaptic membrane or the abnormal oxidative properties of utrophin/dystrophin-deficient muscle. In marked contrast, a dystrophin protein lacking the cysteine-rich domain, which is unable to prevent dystrophy in the mdx mouse, is able to ameliorate these abnormalities in utrophin/dystrophin-deficient mice. These experiments provide the first direct evidence that in addition to a mechanical role and relocalization of the DAPC, dystrophin and utrophin are able to alter both structural and biochemical properties of skeletal muscle. In addition, these mice provide unique insights into skeletal muscle fiber type composition.

  2. First-Principles Study of Electronic Structure of Type I Hybrid Carbon-Silicon Clathrates

    Science.gov (United States)

    Chan, Kwai S.; Peng, Xihong

    2016-08-01

    A new class of type I hybrid carbon-silicon clathrates has been designed using computational methods by substituting some of the Si atoms in the silicon clathrate framework with carbon atoms. In this work, the electronic structure of hybrid carbon-silicon clathrates with and without alkaline or alkaline-earth metal guest atoms has been computed within the density functional theory framework. The theoretical calculations indicate that a small number of carbon substitutions in the Si46 framework slightly reduces the density of states (DOS) near the band edge and narrows the bandgap of carbon-silicon clathrates. Weak hybridization of the conduction band occurs when alkaline metal (Li, Na, K) atoms are inserted into the structure, while strong hybridization of the conduction band occurs when alkaline-earth metal (Mg, Ca, Ba) atoms are inserted into the hybrid structure. Empty C y Si46- y clathrates within the composition range of 2 ≤ y ≤ 15 can be tuned to exhibit indirect bandgaps of 1.5 eV or less, and may be considered as potential electronic materials.

  3. Crystallographic Structure of Porcine Adenovirus Type 4 Fiber Head and Galectin Domains▿

    Science.gov (United States)

    Guardado-Calvo, Pablo; Muñoz, Eva M.; Llamas-Saiz, Antonio L.; Fox, Gavin C.; Kahn, Richard; Curiel, David T.; Glasgow, Joel N.; van Raaij, Mark J.

    2010-01-01

    Adenovirus isolate NADC-1, a strain of porcine adenovirus type 4, has a fiber containing an N-terminal virus attachment region, shaft and head domains, and a C-terminal galectin domain connected to the head by an RGD-containing sequence. The crystal structure of the head domain is similar to previously solved adenovirus fiber head domains, but specific residues for binding the coxsackievirus and adenovirus receptor (CAR), CD46, or sialic acid are not conserved. The structure of the galectin domain reveals an interaction interface between its two carbohydrate recognition domains, locating both sugar binding sites face to face. Sequence evidence suggests other tandem-repeat galectins have the same arrangement. We show that the galectin domain binds carbohydrates containing lactose and N-acetyl-lactosamine units, and we present structures of the galectin domain with lactose, N-acetyl-lactosamine, 3-aminopropyl-lacto-N-neotetraose, and 2-aminoethyl-tri(N-acetyl-lactosamine), confirming the domain as a bona fide galectin domain. PMID:20686025

  4. The structural and molecular biology of type I galactosemia: Enzymology of galactose 1-phosphate uridylyltransferase.

    Science.gov (United States)

    McCorvie, Thomas J; Timson, David J

    2011-09-01

    Reduced galactose 1-phosphate uridylyltransferase (GALT) activity is associated with the genetic disease type I galactosemia. This results in an increase in the cellular concentration of galactose 1-phosphate. The accumulation of this toxic metabolite, combined with aberrant glycoprotein and glycolipid biosynthesis, is likely to be the major factor in molecular pathology. The mechanism of GALT was established through classical enzymological methods to be a substituted enzyme in which the reaction with UDP-glucose results in the formation of a covalent, UMP-histidine adduct in the active site. The uridylated enzyme can then react with galactose 1-phosphate to form UDP-galactose. The structure of the enzyme from Escherichia coli reveals a homodimer containing one zinc (II) and one iron (II) ion per subunit. This enzymological and structural knowledge provides the basis for understanding the biochemistry of this critical step in the Leloir pathway. However, a high-resolution crystal structure of human GALT is required to assist greater understanding of the effects of disease-associated mutations.

  5. Structure of the Pseudomonas aeruginosa Type IVa Pilus Secretin at 7.4 Å.

    Science.gov (United States)

    Koo, Jason; Lamers, Ryan P; Rubinstein, John L; Burrows, Lori L; Howell, P Lynne

    2016-10-04

    Type IVa pili (T4aP) function as bacterial virulence factors. T4aP pass through the outer membranes of Gram-negative bacteria via homo-oligomeric secretins. We present a 7.4 Å cryoelectron microscopy structure of the Pseudomonas aeruginosa PilQ secretin. Peripheral and internal features show that the secretin is composed of 14 subunits with C7 symmetry. The channel is a ribbed cylinder with central peripheral spokes and a central gate closed on the periplasmic side. The structure suggests that during pilus extrusion, the central gate is displaced to the interior walls and that no additional conformational changes are required, as the internal diameter can accommodate the pilus. The N1 domain was resolved, while the N0 and the N-terminal β-domains proposed to bind peptidoglycan were absent in class average images and the final 3D map, indicating a high flexibility. These data provide the highest-resolution structure to date of a T4aP secretin.

  6. Crystal structure of a copper-transporting PIB-type ATPase.

    Science.gov (United States)

    Gourdon, Pontus; Liu, Xiang-Yu; Skjørringe, Tina; Morth, J Preben; Møller, Lisbeth Birk; Pedersen, Bjørn Panyella; Nissen, Poul

    2011-07-01

    Heavy-metal homeostasis and detoxification is crucial for cell viability. P-type ATPases of the class IB (PIB) are essential in these processes, actively extruding heavy metals from the cytoplasm of cells. Here we present the structure of a PIB-ATPase, a Legionella pneumophila CopA Cu(+)-ATPase, in a copper-free form, as determined by X-ray crystallography at 3.2 Å resolution. The structure indicates a three-stage copper transport pathway involving several conserved residues. A PIB-specific transmembrane helix kinks at a double-glycine motif displaying an amphipathic helix that lines a putative copper entry point at the intracellular interface. Comparisons to Ca(2+)-ATPase suggest an ATPase-coupled copper release mechanism from the binding sites in the membrane via an extracellular exit site. The structure also provides a framework to analyse missense mutations in the human ATP7A and ATP7B proteins associated with Menkes' and Wilson's diseases.

  7. Structure and genetic content of the megaplasmids of neurotoxigenic clostridium butyricum type E strains from Italy.

    Science.gov (United States)

    Iacobino, Angelo; Scalfaro, Concetta; Franciosa, Giovanna

    2013-01-01

    We determined the genetic maps of the megaplasmids of six neutoroxigenic Clostridium butyricum type E strains from Italy using molecular and bioinformatics techniques. The megaplasmids are circular, not linear as we had previously proposed. The differently-sized megaplasmids share a genetic region that includes structural, metabolic and regulatory genes. In addition, we found that a 168 kb genetic region is present only in the larger megaplasmids of two tested strains, whereas it is absent from the smaller megaplasmids of the four remaining strains. The genetic region unique to the larger megaplasmids contains, among other features, a locus for clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR associated (cas) genes, i.e. a bacterial adaptive immune system providing sequence-specific protection from invading genetic elements. Some CRISPR spacer sequences of the neurotoxigenic C. butyricum type E strains showed homology to prophage, phage and plasmid sequences from closely related clostridia species or from distant species, all sharing the intestinal habitat, suggesting that the CRISPR locus might be involved in the microorganism adaptation to the human or animal intestinal environment. Besides, we report here that each of four distinct CRISPR spacers partially matched DNA sequences of different prophages and phages, at identical nucleotide locations. This suggests that, at least in neurotoxigenic C. butyricum type E, the CRISPR locus is potentially able to recognize the same conserved DNA sequence of different invading genetic elements, besides targeting sequences unique to previously encountered invading DNA, as currently predicted for a CRISPR locus. Thus, the results of this study introduce the possibility that CRISPR loci can provide resistance to a wider range of invading DNA elements than previously appreciated. Whether it is more advantageous for the peculiar neurotoxigenic C. butyricum type E strains to maintain or to lose the

  8. Structure and genetic content of the megaplasmids of neurotoxigenic clostridium butyricum type E strains from Italy.

    Directory of Open Access Journals (Sweden)

    Angelo Iacobino

    Full Text Available We determined the genetic maps of the megaplasmids of six neutoroxigenic Clostridium butyricum type E strains from Italy using molecular and bioinformatics techniques. The megaplasmids are circular, not linear as we had previously proposed. The differently-sized megaplasmids share a genetic region that includes structural, metabolic and regulatory genes. In addition, we found that a 168 kb genetic region is present only in the larger megaplasmids of two tested strains, whereas it is absent from the smaller megaplasmids of the four remaining strains. The genetic region unique to the larger megaplasmids contains, among other features, a locus for clustered regularly interspaced short palindromic repeats (CRISPR and CRISPR associated (cas genes, i.e. a bacterial adaptive immune system providing sequence-specific protection from invading genetic elements. Some CRISPR spacer sequences of the neurotoxigenic C. butyricum type E strains showed homology to prophage, phage and plasmid sequences from closely related clostridia species or from distant species, all sharing the intestinal habitat, suggesting that the CRISPR locus might be involved in the microorganism adaptation to the human or animal intestinal environment. Besides, we report here that each of four distinct CRISPR spacers partially matched DNA sequences of different prophages and phages, at identical nucleotide locations. This suggests that, at least in neurotoxigenic C. butyricum type E, the CRISPR locus is potentially able to recognize the same conserved DNA sequence of different invading genetic elements, besides targeting sequences unique to previously encountered invading DNA, as currently predicted for a CRISPR locus. Thus, the results of this study introduce the possibility that CRISPR loci can provide resistance to a wider range of invading DNA elements than previously appreciated. Whether it is more advantageous for the peculiar neurotoxigenic C. butyricum type E strains to maintain

  9. Structural and magnetic properties of Fe-Cr-Al alloys with DO{sub 3}-type structure

    Energy Technology Data Exchange (ETDEWEB)

    Satula, D. [Warsaw Univ., Bialystok (Poland). Zaklad Fizyki; Dobrzynski, L. [Warsaw Univ., Bialystok (Poland). Zaklad Fizyki; Waliszewski, J. [Warsaw Univ., Bialystok (Poland). Zaklad Fizyki; Szymanski, K. [Warsaw Univ., Bialystok (Poland). Zaklad Fizyki; Recko, K. [Warsaw Univ., Bialystok (Poland). Zaklad Fizyki; Malinowski, A. [Warsaw Univ., Bialystok (Poland). Zaklad Fizyki; Brueckel, T. [DESY-HASYLAB, Nottkestr. 85, 2000 Hamburg 52 (Germany); Schaerpf, O. [Institute Laue-Langevin, 156X, Grenoble Cedex 38042 (France); Blinowski, K. [Institute of Atomic Energy, 15-400 Otwock-Swierk (Poland)

    1997-05-01

    X-ray, neutron, magnetization and Moessbauer studies in the temperature range 10-300 K are reported for Fe{sub 3-x}Cr{sub x}Al system with x<0.6. The experiments indicate that a single phase having the DO{sub 3}-type structure is maintained in the range of Cr concentration studied. It was found that Cr atoms occupy preferentially B-sites and the lattice constant decreases with increasing concentration of chromium. The magnetic moment of chromium is small and diminishes the value of neighbouring iron atoms by about 0.1 {mu}{sub B} per Cr atom. The magnetic moments of iron at (A, C) and B sites were estimated to be 1.54 (22), 2.58 (22), 1.51 (27) and 2.32 (14) {mu}{sub B} for T=10 and 300 K, respectively. The magnetic moment of iron decreases by 0.37 (10) and 0.26 (6) {mu}{sub B} at 10 K and T=300 K, respectively, if one aluminium atom is found as a nearest neighbour of iron. (orig.).

  10. Mineral Types and Tree Species Determine the Functional and Taxonomic Structures of Forest Soil Bacterial Communities.

    Science.gov (United States)

    Colin, Y; Nicolitch, O; Turpault, M-P; Uroz, S

    2017-03-01

    Although minerals represent important soil constituents, their impact on the diversity and structure of soil microbial communities remains poorly documented. In this study, pure mineral particles with various chemistries (i.e., obsidian, apatite, and calcite) were considered. Each mineral type was conditioned in mesh bags and incubated in soil below different tree stands (beech, coppice with standards, and Corsican pine) for 2.5 years to determine the relative impacts of mineralogy and mineral weatherability on the taxonomic and functional diversities of mineral-associated bacterial communities. After this incubation period, the minerals and the surrounding bulk soil were collected to determine mass loss and to perform soil analyses, enzymatic assays, and cultivation-dependent and -independent analyses. Notably, our 16S rRNA gene pyrosequencing analyses revealed that after the 2.5-year incubation period, the mineral-associated bacterial communities strongly differed from those of the surrounding bulk soil for all tree stands considered. When focusing only on minerals, our analyses showed that the bacterial communities associated with calcite, the less recalcitrant mineral type, significantly differed from those that colonized obsidian and apatite minerals. The cultivation-dependent analysis revealed significantly higher abundances of effective mineral-weathering bacteria on the most recalcitrant minerals (i.e., apatite and obsidian). Together, our data showed an enrichment of Betaproteobacteria and effective mineral-weathering bacteria related to the Burkholderia and Collimonas genera on the minerals, suggesting a key role for these taxa in mineral weathering and nutrient cycling in nutrient-poor forest ecosystems.IMPORTANCE Forests are usually developed on nutrient-poor and rocky soils, while nutrient-rich soils have been dedicated to agriculture. In this context, nutrient recycling and nutrient access are key processes in such environments. Deciphering how soil

  11. Design of a metamaterial slow wave structure for an O-type high power microwave generator

    Science.gov (United States)

    Yurt, Sabahattin C.; Fuks, Mikhail I.; Prasad, Sarita; Schamiloglu, Edl

    2016-12-01

    We describe a new O-type high power microwave oscillator that uses a metamaterial slow wave structure (MSWS) supporting waves with negative dispersion. The MSWS comprises periodically alternating, oppositely oriented split ring resonators (SRRs) connected to a metal tube where the distance between the rings is much less than a wavelength of the radiation generated. The SRRs provide negative permeability μ . The diameter of the metal tube is such that the generated oscillations are below cutoff for a regular waveguide with the same dimension, thus providing negative permittivity ɛ . A tubular electron beam propagates coaxially through this structure. The interaction space is coupled with the outer coaxial channel through gaps between the SRRs. Radiation is extracted in an endfire manner at the end of the outer channel via a conical horn section. Using particle-in-cell (PIC) simulations, it was found that the electron beam in the interaction space forms a sequence of trapped electron bunches by the synchronous operating wave. The output parameters of this oscillator for an applied voltage U = 400 kV, electron beam current I = 4.5 kA, and guide axial magnetic field B = 2 T are radiation power P = 260 MW, radiation frequency f = 1.4 GHz, and electronic efficiency η = 15% when the total SWS length L consisting of 12 split rings is 34.5 cm. The output radiation pattern corresponds to a TE21-like hybrid mode. This article presents details on the simulations of this novel structure and computational and experimental cold tests of a prototype structure in preparation for experimental hot tests.

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

    Science.gov (United States)

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

    2017-02-01

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

  13. High-resolution crystal structure of HA33 of botulinum neurotoxin type B progenitor toxin complex

    Science.gov (United States)

    Lee, Kwangkook; Lam, Kwok-Ho; Kruel, Anna Magdalena; Perry, Kay; Rummel, Andreas; Jin, Rongsheng

    2014-01-01

    Botulinum neurotoxins (BoNTs) are produced as progenitor toxin complexes (PTCs) by Clostridium botulinum. The PTCs are composed of BoNT and non-toxic neurotoxin-associated proteins (NAPs), which serve to protect and deliver BoNT through the gastrointestinal tract in food borne botulism. HA33 is a key NAP component that specifically recognizes host carbohydrates and helps enrich PTC on the intestinal lumen preceding its transport across the epithelial barriers. Here, we report the crystal structure of HA33 of type B PTC (HA33/B) in complex with lactose at 1.46 Å resolution. The structural comparisons among HA33 of serotypes A–D reveal two different HA33–glycan interaction modes. The glycan-binding pockets on HA33/A and B are more suitable to recognize galactose-containing glycans in comparison to the equivalent sites on HA33/C and D. On the contrary, HA33/C and D could potentially recognize Neu5Ac as an independent receptor, whereas HA33/A and B do not. These findings indicate that the different oral toxicity and host susceptibility observed among different BoNT serotypes could be partly determined by the serotype-specific interaction between HA33 and host carbohydrate receptors. Furthermore, we have identified a key structural water molecule that mediates the HA33/B–lactose interactions. It provides the structural basis for development of new receptor-mimicking compounds, which have enhanced binding affinity with HA33 through their water-displacing moiety. PMID:24631690

  14. The deep structure of Alpine-type orogens: how important is rift-inheritance?

    Science.gov (United States)

    Tugend, Julie; Manatschal, Gianreto; Mohn, Geoffroy

    2016-04-01

    in the internal parts of the orogen. The comparison between the deep structure of the Pyrenean and Alpine belts enables us to evaluate some aspects of the relative role of rift-inherited hyperextension and collisional processes in building Alpine-type orogens. In particular, we aim to discuss: (1) the nature of orogenic roots (lower crust vs former hyperextended domains), (2) the nature of rheological weaknesses inherited from hyperextension controlling the location of decoupling levels during orogeny, and (3) the nature and importance of buttresses during collision. Our results suggest that the final stage of collision could have been similar between the Pyrenees and the Alps. More generally, this work may bring new insights to unravel the mountain building processes and the deep structure of Alpine-type orogens.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-10-05

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

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

    Directory of Open Access Journals (Sweden)

    Picking Wendy L

    2010-07-01

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

  17. Structural Analysis and Improved Design of the Gearbox Casing of a Certain Type of Tracked Vehicle

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xue-sheng; JIA Xiao-ping; CHEN Ya-ning; YU Kui-long

    2011-01-01

    Loads on a gearbox casing of a certain type of tracked vehicle were calculated according to the engine's full load characteristic curve and the worst load condition where the gearbox operated while the tracked vehicle was running, and then stiffness and strength of the casing were analyzed by means of Patran/Nastran software. After a- nalysis, it was found that the casing satisfied the Mises ' yield condition; however, the stress distribution was hetero- geneous, and stresses near the bearing saddle bores of the casing were higher while those in other regions were much less than the allowable stress. For this reason, thicknesses of the casing wall on bearing assembling holes needed in- creasing, while those in other places can decrease. After much structural improving and re-analysis, the optimal casing design was found, and its weight decreased by 5% ; the casing still satisfied the Mises yield criterion and the stress distribution was more homogeneous.

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

    Directory of Open Access Journals (Sweden)

    Aleksey I. Kochaev

    2017-02-01

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

  19. Low dimentional magnetic properties of compounds belonging to the CrVO{sub 4}-type structure

    Energy Technology Data Exchange (ETDEWEB)

    Law, Joseph M. [Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart (Germany); Department of Physics Loughborough University, Loughborough, Leics, LE11 3TU (United Kingdom); Kremer, Reinhard K. [Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart (Germany)

    2011-07-01

    Compounds with the ABX{sub 4} composition exhibit a range of different magnetic properties. In recent years we have concentrated on only those adopting the CrVO{sub 4}-type structure, where we have a magnetic atom occupying the A position and a diamagnetic only atom within the B position. The A atom is housed within a distorted octahedral environment, the AO{sub 6} units are edge sharing and form buckled ribbon chains along the c-axis. The B atoms are contained within tetrahedral Oxygen environments which bridge the ribbon chains. We are present first results on the magnetic properties of some selected of this series which show, multiferroic behavior, spin-Peierls transitions and conventional long-range magnetic ordering.

  20. Composition, structure and function of the Helicobacter pylori cag pathogenicity island encoded type IV secretion system.

    Science.gov (United States)

    Backert, Steffen; Tegtmeyer, Nicole; Fischer, Wolfgang

    2015-01-01

    Many Gram-negative pathogens harbor type IV secretion systems (T4SS) that translocate bacterial virulence factors into host cells to hijack cellular processes. The pathology of the gastric pathogen Helicobacter pylori strongly depends on a T4SS encoded by the cag pathogenicity island. This T4SS forms a needle-like pilus, and its assembly is accomplished by multiple protein-protein interactions and various pilus-associated factors that bind to integrins followed by delivery of the CagA oncoprotein into gastric epithelial cells. Recent studies revealed the crystal structures of six T4SS proteins and pilus formation is modulated by iron and zinc availability. All these T4SS interactions are crucial for deregulating host signaling events and disease progression. New developments in T4SS functions and their importance for pathogenesis are discussed.

  1. Formation of the structure and properties of β-type titanium alloy upon thermomechanical treatment

    Science.gov (United States)

    Shaboldo, O. P.; Vitorskii, Ya. M.; Sagaradze, V. V.; Pecherkina, N. L.; Skotnikova, M. A.

    2017-01-01

    The rapid quenching of β-type titanium alloy from 800°C and cold deformation by drawing (ɛ = 24%) leads to the formation of a cellular-banded structure with a cell size of 200 × 400 nm and high density of dislocations ( 5 × 1014 m-2). During subsequent aging at 450°C, the decomposition of the β-phase occurs with a heterogeneous precipitation (at dislocations) of plates of the α phase with a thickness of 10-30 nm and length of 50-100 nm. The small size and high density of α crystals (5 × 1021 m-3) provide a substantial increase in the strength characteristics of the alloy.

  2. New Copper and Oxomolybdate Robson-Type Polynuclear Macrocyclic Complexes: Structure, Spectroscopy, and Electrochemical Properties

    Directory of Open Access Journals (Sweden)

    Marcelo Carpes Nunes

    2015-01-01

    Full Text Available The polynuclear complexes [Mo3O8(tidf]·dmso·2H2O (1 and [{Cu2(tidf}2(μ-Mo8O24] (2 (tidf2− is a symmetrical tetraiminodiphenolate Robson-type macrocyclic ligand were prepared from equimolar combinations of [Mg2(tidf](NO32·4H2O, [MoO2Cl2(dmso2] (for 1 and complex 1 and Cu(ClO42·4H2O (for 2 in acetonitrile. Molecular structures of both complexes were determined and showed atypical modes of coordination. A significant observation was the remarkable flexibility of the macrocycle ligand that effectively accommodated the steric demands of metal cations and the packing forces and showed a unique mode of coordination. Spectroscopic (UV-vis and FTIR and redox properties are discussed.

  3. Structural requirements of the major protective antibody to Haemophilus influenzae type b

    DEFF Research Database (Denmark)

    Hougs, L; Juul, L; Svejgaard, A

    1999-01-01

    expressed as antigen-binding fragments (Fabs) in Escherichia coli, define amino acids involved in antigen binding and idiotype expression, and propose a three-dimensional structure for the variable domains. We found that canonical Fabs, unlike a noncanonical Fab, bound effectively to HibCP in the absence......Protective antibodies to the important childhood pathogen Haemophilus influenzae type b (Hib) are directed against the capsular polysaccharide (HibCP). Most of the antibody is encoded by a well-defined set of ("canonical") immunoglobulin genes, including the Vkappa A2 gene, and expresses...... an idiotypic marker (HibId-1). In comparison to noncanonical antibodies, the canonical antibody is generally of higher avidity, shows higher levels of in vitro bactericidal activity, and is more protective in infant rats. Using site-directed mutagenesis, we here characterize canonical HibCP antibodies...

  4. Fine structure of type-I edge-localized modes in the steep gradient region.

    Science.gov (United States)

    Kurzan, B; Murmann, H D; Neuhauser, J

    2005-09-30

    Fast, high resolution multichannel Thomson scattering is used to quantitatively determine plasma perturbations induced by type-I edge-localized modes (ELMs) in the low-field side edge of ASDEX Upgrade H-mode plasmas. 2D snapshots of temperature and density, deduced from the laser light scattered in a vertically elongated, poloidal array of 5 x 10 scattering volumes, are obtained in the hot, steep edge gradient zone, which is difficult to access by other diagnostics. Local maxima and minima with large amplitude are identified during ELMs and even in the precursor phase, both in density and temperature. Interpreting these structures as footprints of approximately field aligned helical modes in accordance with previous experimental and theoretical work, toroidal mode numbers between 8 and 20 are obtained, roughly consistent with corresponding scrape-off layer and divertor measurements.

  5. Types of Structure and Sustainability of Forest Shelter Belts in the Southern Part of Central Siberia

    Directory of Open Access Journals (Sweden)

    G. S. Varaksin

    2014-06-01

    Full Text Available The series of tree stem diameter distributions has been basis for study tree stand structure in forest shelter belts. The measurements were carried out in forest shelter belts of the southern part of the Central Siberia. Experimental sample plots have been established in the Republic of Khakassia (Ust-Abakan, Beisk, and Shira districts, Krasnoyarsk Territory (Shushenskoe and Minusinsk districts, and the Republic of Tuva (Kyzyl district. The analysis of tree stem diameter distributions series allowed making reference table in determining the shape of distributions in the forest shelter belts. The evaluation involves allocation of six types of the tree stem diameter series: symmetric, left asymmetric, right asymmetric, peak, flat, and pectinate. Comparing agro-technical features of creating tree stands and distributions series of the tree stem diameters, the optimal parameters in terms of sustainability for different tree species has been determined.

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

    Science.gov (United States)

    Chen, Pengmin; Zhao, Jingbo; Yang, Xin; Zhao, Tingting; Yan, Meihua; Pan, Lin; Li, Xin; Zhang, Yun

    2017-01-01

    Aim. This study investigated the effect and mechanism of the Chinese herbal medicine Tangshen Formula (TSF) on GI structure remodeling in the rat model of diabetes. Methods. Type 2 diabetic rats were used. Wet weight per unit length, layer thicknesses, levels of collagens I and III, nuclear factor kappa B (NF-κB), interferon-γ (IFN-γ), interleukin-6 (IL-6), transforming growth factor-β1 (TGF-β1), and Smad2/3 expression in the rat colon were measured. Results. Compared with the control group animals, wet weight and layer thicknesses of the colon increased, and expressions of collagens I and III, NF-κB, IFN-γ, IL-6, TGF-β1, and Smad2/3 increased significantly in the diabetic animals. TSF inhibited increase in colonic wet weight and layer thicknesses, downregulated expressions of collagens I and III in the mucosal layer, and downregulated expressions of NF-κB, IFN-γ, IL-6, TGF-β1, and Smad2/3 in the colon wall. Furthermore, level of expression of NF-κB was associated with those of TGF-β1 and Smad2/3. Expression of TGF-β1 was associated with the most histomorphometric parameters including colonic weight, mucosal and muscle thicknesses, and levels of collagens I and III in mucosal layer. Conclusion. TSF appears to attenuate colonic structure remodeling in type 2 diabetic rats through inhibiting the overactivated pathway of NF-κB, thus reducing expressions of TGF-β1.

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

    Science.gov (United States)

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

    2015-09-07

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

  8. Structure, properties, and bonding of ZrTe (MnP type), a low-symmetry, high-temperature modification of ZrTe (WC type).

    Science.gov (United States)

    Orlygsson, G; Harbrecht, B

    2001-05-09

    ZrTe (MnP) was synthesized by high-temperature methods at 1570 K in Ta ampules. The structure of the telluride was determined by means of single-crystal X-ray diffraction to be orthorhombic, Pnma (No. 62), Z = 4, Pearson Symbol oP8, a = 739.15(15) pm, b = 377.23(8) pm, c = 694.34(14) pm. The orthorhombic MnP type structure is a distorted variant of the NiAs type structure with pronounced metal-metal zigzag chains. Zigzag chains are typical for phases with a d(2) metal atom electron configuration. According to extended Hückel calculations, the homonuclear interactions in the zigzag chains make up for 2/3 of the Zr-Zr interactions in ZrTe (MnP) and contribute decisively to the stability of the structure. The emergence of the distorted MnP type structure instead of the high-symmetry NiAs type ZrTe at high temperatures can be understood as the result of an optimization of homonuclear Zr-Zr interactions arising from states close to the Fermi level. The hexagonal WC type ZrTe transforms above 1438 +/- 5 K into ZrTe (MnP) (DeltaH = 8.3 +/- 1.0 kJ mol(-1)). The phase transition is reversible, although at room-temperature the reverse reaction is kinetically inhibited. Zr5Te4 and Zr5Te6 are the phases next to ZrTe. ZrTe (MnP) exhibits temperature-independent paramagnetic properties (chi(mol) = 0.14 x 10(-3) cm(3) mol(-1)), as typical for a metallic conductor. Resistivity measurements on ZrTe (MnP) imply metallic behavior.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Upinder K. Dhand

    2013-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Dongliang Chu

    2015-09-01

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

  12. Polyester type polyHIPE scaffolds with an interconnected porous structure for cartilage regeneration

    Science.gov (United States)

    Naranda, Jakob; Sušec, Maja; Maver, Uroš; Gradišnik, Lidija; Gorenjak, Mario; Vukasović, Andreja; Ivković, Alan; Rupnik, Marjan Slak; Vogrin, Matjaž; Krajnc, Peter

    2016-06-01

    Development of artificial materials for the facilitation of cartilage regeneration remains an important challenge in orthopedic practice. Our study investigates the potential for neocartilage formation within a synthetic polyester scaffold based on the polymerization of high internal phase emulsions. The fabrication of polyHIPE polymer (PHP) was specifically tailored to produce a highly porous (85%) structure with the primary pore size in the range of 50–170 μm for cartilage tissue engineering. The resulting PHP scaffold was proven biocompatible with human articular chondrocytes and viable cells were observed within the materials as evaluated using the Live/Dead assay and histological analysis. Chondrocytes with round nuclei were organized into multicellular layers on the PHP surface and were observed to grow approximately 300 μm into the scaffold interior. The accumulation of collagen type 2 was detected using immunohistochemistry and chondrogenic specific genes were expressed with favorable collagen type 2 to 1 ratio. In addition, PHP samples are biodegradable and their baseline mechanical properties are similar to those of native cartilage, which enhance chondrocyte cell growth and proliferation.

  13. Structure and stability of monazite- and zircon-type LaVO4 under hydrostatic pressure

    Science.gov (United States)

    Cheng, Xuerui; Guo, Dongjie; Feng, Shiquan; Yang, Kun; Wang, Yongqiang; Ren, Yufen; Song, Yang

    2015-11-01

    Pure monazite (m)- and zircon (t)-type LaVO4 and LaVO4:Eu3+ were successfully synthesized by a hydrothermal method. The high pressure behavior of m- and t-LaVO4 nanoparticles has been investigated using Raman scattering techniques at room temperature. Raman measurements reveal a slight change for m-LaVO4 at 11.2 GPa because of an isostructural phase transition. However, striking changes in Raman spectra indicate a pressure-induced irreversible phase transition from the zircon to monazite structure for t-LaVO4 at around 5.9 GPa. The evolution of the luminescence spectra of t-LaVO4:Eu3+ has also been studied during the pressure-induced phase transition. It is observed that pressure has a great influence on the fluorescence intensity and the energy levels, which allows a more in-depth understanding of the nature of the pressure-induced phase transition for t-LaVO4. This result further confirms the conclusion that zircon-type RVO4 compounds with larger rare-earth cations will experience zircon to monazite phase transition.

  14. Population structure of the Yersinia pseudotuberculosis complex according to multilocus sequence typing

    Science.gov (United States)

    Laukkanen-Ninios, Riikka; Didelot, Xavier; Jolley, Keith A.; Morelli, Giovanna; Sangal, Vartul; Kristo, Paula; Imori, Priscilla F. M.; Fukushima, Hiroshi; Siitonen, Anja; Tseneva, Galina; Voskressenskaya, Ekaterina; Falcao, Juliana P.; Korkeala, Hannu; Maiden, Martin C. J.; Mazzoni, Camila; Carniel, Elisabeth; Skurnik, Mikael; Achtman, Mark

    2014-01-01

    Summary Multilocus sequence analysis of 417 strains of Yersinia pseudotuberculosis revealed that it is a complex of four populations, three of which have been previously assigned species status [Y. pseudotuberculosis sensu stricto (s.s.), Yersinia pestis and Yersinia similis] and a fourth population, which we refer to as the Korean group, which may be in the process of speciation. We detected clear signs of recombination within Y. pseudotuberculosis s.s. as well as imports from Y. similis and the Korean group. The sources of genetic diversification within Y. pseudotuberculosis s.s. were approximately equally divided between recombination and mutation, whereas recombination has not yet been demonstrated in Y. pestis, which is also much more genetically monomorphic than is Y. pseudotuberculosis s.s. Most Y. pseudotuberculosis s.s. belong to a diffuse group of sequence types lacking clear population structure, although this species contains a melibiose-negative clade that is present globally in domesticated animals. Yersinia similis corresponds to the previously identified Y. pseudotuberculosis genetic type G4, which is probably not pathogenic because it lacks the virulence factors that are typical for Y. pseudotuberculosis s.s. In contrast, Y. pseudotuberculosis s.s., the Korean group and Y. pestis can all cause disease in humans. PMID:21951486

  15. Geographical and Temporal Structures of Legionella pneumophila Sequence Types in Comunitat Valenciana (Spain), 1998 to 2013.

    Science.gov (United States)

    Sánchez-Busó, Leonor; Coscollà, Mireia; Palero, Ferran; Camaró, María Luisa; Gimeno, Ana; Moreno, Pilar; Escribano, Isabel; López Perezagua, María Mar; Colomina, Javier; Vanaclocha, Herme; González-Candelas, Fernando

    2015-10-01

    Legionella pneumophila is an accidental human pathogen associated with aerosol formation in water-related sources. High recombination rates make Legionella populations genetically diverse, and nearly 2,000 different sequence types (STs) have been described to date for this environmental pathogen. The spatial distribution of STs is extremely heterogeneous, with some variants being present worldwide and others being detected at only a local scale. Similarly, some STs have been associated with disease outbreaks, such as ST578 or ST23. Spain is among the European countries with the highest incidences of reported legionellosis cases, and specifically, Comunitat Valenciana (CV) is the second most affected area in the country. In this work, we aimed at studying the overall diversity of Legionella pneumophila populations found in the period from 1998 to 2013 in 79 localities encompassing 23 regions within CV. To do so, we performed sequence-based typing (SBT) on 1,088 L. pneumophila strains detected in the area from both environmental and clinical sources. A comparison with the genetic structuring detected in a global data set that included 20 European and 7 non-European countries was performed. Our results reveal a level of diversity in CV that can be considered representative of the diversity found in other countries worldwide.

  16. Ce{sup 3+} incorporated structural and magnetic properties of M type barium hexaferrites

    Energy Technology Data Exchange (ETDEWEB)

    Pawar, R.A. [Department of Physics, Arts, Commerce and Science College, Satral, MS (India); Desai, S.S.; Tamboli, Q.Y. [Materials Research Laboratory, Shrikrishna Mahavidyalaya, Gunjoti 413613, MS (India); Shirsath, Sagar E. [Spin Device Technology Center, Faculty of Engineering, Shinshu University, Nagano 380-8553 (Japan); Patange, S.M., E-mail: smpatange@rediffmail.com [Materials Research Laboratory, Shrikrishna Mahavidyalaya, Gunjoti 413613, MS (India)

    2015-03-15

    M type barium hexaferrites BaCe{sub x}Fe{sub 12−x}O{sub 19} (0≤x≤0.3) (BCFO) were synthesized by the sol–gel auto combination method. Optimum annealing temperature of hexagonal phase was determined by using the TGA analysis. The annealing temperature form the TGA is 1000 °C samples annealed 1000 °C for 5 h to produce M type hexaferrites. X-ray diffraction data run to full Prof Program (Winploter 2010) pattern indicate that samples are single phase hexagonal structure with space group P6{sub 3}/mmc. Lattice parameter ‘a’ and ‘c’ increase with increase in Ce content x. Results of field emission scanning electron microscope show that the grains are regular hexagonal platelets with sizes from 0.3 to 1.4 μm. It is observed that from M–H curve value of the saturation magnetization and coercivity decreases with increasing x. Curie temperature from magnetization with temperature plot is found to decrease with Ce{sup 3+} substitution x due to decreases in magnetic interaction. - Highlights: • Ce{sup 3+} substituted Ba hexaferrites. • Increased coercivity with Ce{sup 3+} substitution. • Decrease in saturation magnetization and Curie temperature.

  17. Analysis of the population structure of Anaplasma phagocytophilum using multilocus sequence typing.

    Directory of Open Access Journals (Sweden)

    Christian Huhn

    Full Text Available Anaplasma phagocytophilum is a Gram-negative obligate intracellular bacterium that replicates in neutrophils. It is transmitted via tick-bite and causes febrile disease in humans and animals. Human granulocytic anaplasmosis is regarded as an emerging infectious disease in North America, Europe and Asia. However, although increasingly detected, it is still rare in Europe. Clinically apparent A. phagocytophilum infections in animals are mainly found in horses, dogs, cats, sheep and cattle. Evidence from cross-infection experiments that A. phagocytophilum isolates of distinct host origin are not uniformly infectious for heterologous hosts has led to several approaches of molecular strain characterization. Unfortunately, the results of these studies are not always easily comparable, because different gene regions and fragment lengths were investigated. Multilocus sequence typing is a widely accepted method for molecular characterization of bacteria. We here provide for the first time a universal typing method that is easily transferable between different laboratories. We validated our approach on an unprecedented large data set of almost 400 A. phagocytophilum strains from humans and animals mostly from Europe. The typability was 74% (284/383. One major clonal complex containing 177 strains was detected. However, 54% (49/90 of the sequence types were not part of a clonal complex indicating that the population structure of A. phagocytophilum is probably semiclonal. All strains from humans, dogs and horses from Europe belonged to the same clonal complex. As canine and equine granulocytic anaplasmosis occurs frequently in Europe, human granulocytic anaplasmosis is likely to be underdiagnosed in Europe. Further, wild boars and hedgehogs may serve as reservoir hosts of the disease in humans and domestic animals in Europe, because their strains belonged to the same clonal complex. In contrast, as they were only distantly related, roe deer, voles and

  18. Woody species composition, diversity and structure of riparian forests of four watercourses types in Burkina Faso

    Institute of Scientific and Technical Information of China (English)

    Oumarou Sambaré; Fidèle Bognounou; Rüdiger Wittig; Adjima Thiombiano

    2011-01-01

    Riparian forests are classified as endangered ecosystems in general, particularly in sahelian countries like Burkina Faso because of human-induced alterations and civil engineering works. The modification of this important habitat is continuing, with little attention being paid to the ecological or human consequences of these changes. The objective of this study is to describe the variation of woody species diversity and dynamic in riparian forests on different type of watercourse banks along phytogeographical gradient in Burkina Faso. All woody species were systematically measured in 90 sample plots with sides of 50 m × 20 m.Density, dominance, frequency and species and family importance values were computed to characterize the species composition. Different diversity indices were calculated to examine the heterogeneity of riparian forests. A total of 196 species representing 139 genera and 51 families were recorded in the overall riparian forests. The species richness of individuals with dbh ≥ 5cm increased significantly from the North to the South along the phytogeographical gradient and varied significantly between the different types of riparian forests. Similarity in tree species composition between riparian forests was low, which indicates high beta diversity and reflects differences in habitat conditions and topography.The structural characteristics varied significantly along the phytogeographical gradient and between the different types of riparian forests.The diameter class distribution of trees in all riparian forests showed a reverse “J” shaped curve except riparian forest of stream indicating vegetation dominated by juvenile individuals. Considering the ecological importance of riparian forest, there is a need to delineate and classify them along watercourses throughout the country.

  19. Structural and phase transformations in the low-temperature annealed amorphous “finemet”-type microwires

    Energy Technology Data Exchange (ETDEWEB)

    Tcherdyntsev, V.V., E-mail: vvch08@yandex.ru [National University of Science and Technology “MISIS”, Moscow 119049 (Russian Federation); Aleev, A.A. [SSC RF Institute for Theoretical and Experimental Physics, Moscow 117218 (Russian Federation); Churyukanova, M.N.; Kaloshkin, S.D. [National University of Science and Technology “MISIS”, Moscow 119049 (Russian Federation); Medvedeva, E.V. [Institute of Electrophysics, Ural Branch, Russian Academy of Sciences, Yekaterinburg 620016 (Russian Federation); Korchuganova, O.A. [SSC RF Institute for Theoretical and Experimental Physics, Moscow 117218 (Russian Federation); Zhukova, V. [Dpto. de Fns. Mater., UPV/EHU, San Sebastian 20018 (Spain); Zhukov, A.P. [Dpto. de Fns. Mater., UPV/EHU, San Sebastian 20018 (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain)

    2014-02-15

    Highlights: • Structure and magnetic properties evolution at heating of amorphous microwires was studied. • Relaxation processes in the amorphous phase correlate with an increase in Curie temperature. • Curie temperature change can not be stabilized by a prolonged exposure at pre-crystallization temperatures. • Tomographic atom probe microscopy supports the formation of α-Fe phase precipitations enriched in Si. -- Abstract: Finemet-type glass-coated microwires with amorphous and nanocrystalline structure have been investigated. The relaxation and crystallization processes at heating of amorphous alloy have been studied by DSC method. We observed that the relaxation processes in the amorphous phase correlate with an increasing of the Curie temperature. Additionally a prolonged exposure of the samples below the crystallization temperatures does not stabilize the Curie temperature change. An investigation by the tomographic atom probe microscopy supports the formation of precipitations, probably α-Fe phase, as a result of low-temperature annealing (400 °C, 5 min). We found that the observed nano-sized areas were enriched in silicon.

  20. Durability improvement assessment in different high strength bacterial structural concrete grades against different types of acids

    Indian Academy of Sciences (India)

    Ramin Andalib; M Zaimi Abd Majid; A Keyvanfar; Amirreza Talaiekhozan; Mohd Warid Hussin; A Shafaghat; Rosli Mohd Zin; Chew Tin Lee; Mohammad Ali Fulazzaky; Hasrul Haidar Ismail

    2014-12-01

    This paper provides an insight into a new biotechnological method based on calcite precipitation for achieving high strength bio-concrete durability. It is very clear that mineral precipitation has the potential to enhance construction material resistance towards degradation procedures. The appropriate microbial cell concentration (30 * 105 cells/ml) was introduced onto different structural concrete grades (40, 45 and 50 MPa) by mixing water. In order to study the durability of structural concrete against aggressive agents, specimens were immersed in different types of acids solution (5% H2SO4 and HCl) to compare their effects on 60th, 90th and 120th day. In general, sulphuric acid and hydrochloric acid are known to be the most aggressive natural threats from industrial waters which can penetrate concrete to transfer the soluble calcium salts away from the cement matrix. The experimental results demonstrated that bio-concrete has less weight and strength losses when compared to the ordinary Portland cement concrete without microorganism. It was also found that maximum compressive strength and weight loss occurred during H2SO4 acid immersion as compared to HCl immersion. The density and uniformity of bio-concrete were examined using ultrasonic pulse velocity (UPV) test. Microstructure chemical analysis was also quantified by energy dispersive spectrometer (EDS) to justify the durability improvement in bacterial concrete. It was observed that less sulphur and chloride were noticed in bacterial concrete against H2SO4 and HCl, respectively in comparison to the ordinary Portland cement concrete due to calcite deposition.

  1. Ion beam irradiation effects in strontium zirconium phosphate with NZP-structure type

    Energy Technology Data Exchange (ETDEWEB)

    Gregg, Daniel J., E-mail: daniel.gregg@ansto.gov.au [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Karatchevtseva, Inna; Thorogood, Gordon J.; Davis, Joel [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Bell, Benjamin D.C.; Jackson, Matthew [Department of Materials, Imperial College, London SW7 2BP (United Kingdom); Dayal, Pranesh [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Ionescu, Mihail [Institute of Environment Science, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Triani, Gerry; Short, Ken; Lumpkin, Gregory R.; Vance, Eric R. [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia)

    2014-03-15

    Ceramics with the sodium zirconium phosphate or NZP type structure have potential as nuclear waste form and inert matrix materials. For both applications the material will be subjected to self-radiation damage from α-decay of the incorporated actinides. In this study, ion-beam irradiation using Au- and He-ions has been used to simulate the consequences of α-decay and the effects of irradiation on the structural and macroscopic properties (density and hardness) have been investigated. Irradiation by Au-ions resulted in a significant volume contraction of ∼7%, a reduction in hardness of ∼30% and a loss in long-range order at fluences above 10{sup 14} Au-ions/cm{sup 2}. In contrast, little effect on the material properties was noted for samples irradiated with He-ions up to a fluence of 10{sup 17} ions/cm{sup 2}. Thermal annealing was investigated for the highest fluence Au-ion irradiated sample and significant decomposition was observed.

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

    Science.gov (United States)

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

    2003-01-01

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

  3. Free Volume Structure of Acrylic-Type Dental Nanocomposites Tested with Annihilating Positrons

    Science.gov (United States)

    Shpotyuk, Olha; Ingram, Adam; Shpotyuk, Oleh

    2016-11-01

    Positron annihilation spectroscopy in lifetime measuring mode exploring conventional fast-fast coincidence ORTEC system is employed to characterize free volume structure of commercially available acrylic-type dental restorative composite Charisma® (Heraeus Kulzer GmbH, Germany). The measured lifetime spectra for uncured and light-cured composites are reconstructed from unconstrained x3-term fitting and semi-empirical model exploring x3-x2-coupling decomposition algorithm. The governing channel of positron annihilation in the composites studied is ascribed to mixed positron-Ps trapping, where Ps decaying in the third component is caused entirely by input from free-volume holes in polymer matrix, while the second component is defined by free positron trapping in interfacial free-volume holes between filler nanoparticles and surrounded polymer matrix. Microstructure scenario of the photopolymerization shrinkage includes cross-linking of structural chains in polymer matrix followed by conversion of bound positron-electron (positronium) traps in positron-trapping interfacial free-volume voids in a vicinity of agglomerated filler nanoparticles.

  4. Antimicrobial structure activity relationship of five anthraquinones of emodine type isolated from Vismia laurentii.

    Science.gov (United States)

    Kemegne, Gislaine Aurelie; Mkounga, Pierre; Essia Ngang, Jean Justin; Sado Kamdem, Sylvain Leroy; Nkengfack, Augustin Ephrem

    2017-02-22

    Antimicrobial activity of anthraquinone compounds of emodine type has been reported by many authors. These compounds are found in Vismia laurentii (Clusiaceae), a plant used in traditional pharmacopoeia for treatment of microbial infections among others affections. The continuous identification of new compounds has raised the problem of the relation between the structure and antimicrobial properties. The yeast growth kinetics parameters were not influenced by the pH variation as it was the case for the other tested bacteria. Fungicidal activities were noted for all molecules while only few of them had bactericidal activities, mostly on Gram positive bacteria. Mathematical model establishing a quantitative relationship between physicochemical properties of molecules and their fungicidal activities were obtained for Candida albicans and showed that physicochemical properties impacting on antifungal activity were polarizability, partition coefficient, molecular weight and hydrogen bond acceptor. This work demonstrated that the presence of a long aliphatic chain methoxy group substituted in position two of the emodine structure increased the antibacterial properties of the studied compounds. Moreover this antimicrobial property depends on the pH of the environment, and specifically on the polarizability and number of hydrogen bond acceptors of the compound.

  5. Structural transformations in femtosecond laser-processed n-type 4H-SiC

    Science.gov (United States)

    Rehman, Z. U.; Janulewicz, K. A.

    2016-11-01

    We present a comprehensive study of morphological modification induced on and below the surface of n-type 4H-SiC by irradiation with femtosecond laser pulses under tight focusing condition. Spectroscopic investigation of local electronic and structural transformations in SiC-micro/nanostructures suggested bond breaking i.e. transformation of crystalline SiC to amorphous silicon (a-Si) and amorphous carbon (a-C). These observations were augmented by investigations applying atomic force microscopy (AFM), micro-photoluminescence (PL) spectroscopy, and high resolution X-ray diffraction (HRXRD). A high-resolution cross-sectional study of laser-modified region with transmission electron microscope (TEM) showed a thin amorphous layer in the vicinity of the geometrical focus with deformations and stacking faults in the sub-surface area. Having considered the existing ablation theories, a complex interplay of fast laser heating followed by melting and rapid re-solidification as well as dynamic relaxation of the laser-induced stresses seems to be responsible for formation of the observed structural changes.

  6. Cloud cover typing from environmental satellite imagery. Discriminating cloud structure with Fast Fourier Transforms (FFT)

    Science.gov (United States)

    Logan, T. L.; Huning, J. R.; Glackin, D. L.

    1983-01-01

    The use of two dimensional Fast Fourier Transforms (FFTs) subjected to pattern recognition technology for the identification and classification of low altitude stratus cloud structure from Geostationary Operational Environmental Satellite (GOES) imagery was examined. The development of a scene independent pattern recognition methodology, unconstrained by conventional cloud morphological classifications was emphasized. A technique for extracting cloud shape, direction, and size attributes from GOES visual imagery was developed. These attributes were combined with two statistical attributes (cloud mean brightness, cloud standard deviation), and interrogated using unsupervised clustering amd maximum likelihood classification techniques. Results indicate that: (1) the key cloud discrimination attributes are mean brightness, direction, shape, and minimum size; (2) cloud structure can be differentiated at given pixel scales; (3) cloud type may be identifiable at coarser scales; (4) there are positive indications of scene independence which would permit development of a cloud signature bank; (5) edge enhancement of GOES imagery does not appreciably improve cloud classification over the use of raw data; and (6) the GOES imagery must be apodized before generation of FFTs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Locatelli, C

    1999-01-01

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

  8. Clathrate structure-type recognition: Application to hydrate nucleation and crystallisation.

    Science.gov (United States)

    Lauricella, Marco; Meloni, Simone; Liang, Shuai; English, Niall J; Kusalik, Peter G; Ciccotti, Giovanni

    2015-06-28

    For clathrate-hydrate polymorphic structure-type (sI versus sII), geometric recognition criteria have been developed and validated. These are applied to the study of the rich interplay and development of both sI and sII motifs in a variety of hydrate-nucleation events for methane and H2S hydrate studied by direct and enhanced-sampling molecular dynamics (MD) simulations. In the case of nucleation of methane hydrate from enhanced-sampling simulation, we notice that already at the transition state, ∼80% of the enclathrated CH4 molecules are contained in a well-structured (sII) clathrate-like crystallite. For direct MD simulation of nucleation of H2S hydrate, some sI/sII polymorphic diversity was encountered, and it was found that a realistic dissipation of the nucleation energy (in view of non-equilibrium relaxation to either microcanonical (NVE) or isothermal-isobaric (NPT) distributions) is important to determine the relative propensity to form sI versus sII motifs.

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

    Science.gov (United States)

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

    2014-02-21

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

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

    Science.gov (United States)

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

    2012-02-14

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

  11. Response Analyses of Tuned Mass Dampers to Structures Exposed to Vortex Loading of Simiu-Scanlan Type

    DEFF Research Database (Denmark)

    Andersen, Lars; Birch, N. W.; Hansen, A. H.

    2001-01-01

    Vortex-induced loads on slender one-dimensional structures vibrating at lock-in conditions consist of a self-induced part in phase with the velocity of the structure in addition to an additive, almost harmonially varying component representing the same type of load as the vortex-induced force on ...

  12. Structural basis of specific inhibition of tissue-type plasminogen activator by plasminogen activators inhibitor-1

    Directory of Open Access Journals (Sweden)

    Lihu Gong

    2016-03-01

    Full Text Available Thrombosis is a leading cause of death worldwide [1]. Recombinant tissue-type plasminogen activator (tPA is the FDA-approved thrombolytic drug for ischemic strokes, myocardial infarction and pulmonary embolism. tPA is a multi-domain serine protease of the trypsin-family [2] and catalyses the critical step in fibrinolysis [3], converting the zymogen plasminogen to the active serine protease plasmin, which degrades the fibrin network of thrombi and blood clots. tPA is rapidly inactivated by endogenous plasminogen activators inhibitor-1 (PAI-1 [4] (Fig. 1. Engineering on tPA to reduce its inhibition by PAI-1 without compromising its thrombolytic effect is a continuous effort [5]. Tenecteplase (TNK-tPA is a newer generation of tPA variant showing slower inhibition by PAI-1 [6]. Extensive studies to understand the molecular interactions between tPA and PAI-1 have been carried out [7–18], however, the precise details at atomic resolution remain unknown. We report the crystal structure of tPA·PAI-1 complex here. The methods required to achieve these data include: (1 recombinant expression and purification of a PAI-1 variant (14-1B containing four mutations (N150H, K154T, Q319L, and M354I, and a tPA serine protease domain (tPA-SPD variant with three mutations (C122A, N173Q, and S195A, in the chymotrypsin numbering [19]; (2 formation of a tPA-SPD·PAI-1 Michaëlis complex in vitro [19]; and (3 solving the three-dimensional structure for this complex by X-ray crystallography [deposited in the PDB database as 5BRR]. The data explain the specificity of PAI-1 for tPA and uPA [19,20], and provide structural basis to design newer generation of PAI-1-resistant tPA variants as thrombolytic agents [19].

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

    Science.gov (United States)

    Korotkov, Konstantin V; Hol, Wim G J

    2013-05-01

    Bacteria contain several sophisticated macromolecular machineries responsible for translocating proteins across the cell envelope. One prominent example is the type II secretion system (T2SS), which contains a large outer membrane channel, called the secretin. These gated channels require specialized proteins, so-called pilotins, to reach and assemble in the outer membrane. Here we report the crystal structure of the pilotin GspS from the T2SS of enterohemorrhagic Escherichia coli (EHEC), an important pathogen that can cause severe disease in cases of food poisoning. In this four-helix protein, the straight helix α2, the curved helix α3 and the bent helix α4 surround the central N-terminal helix α1. The helices of GspS create a prominent groove, mainly formed by side chains of helices α1, α2 and α3. In the EHEC GspS structure this groove is occupied by extra electron density which is reminiscent of an α-helix and corresponds well with a binding site observed in a homologous pilotin. The residues forming the groove are well conserved among homologs, pointing to a key role of this groove in this class of T2SS pilotins. At the same time, T2SS pilotins in different species can be entirely different in structure, and the pilotins for secretins in non-T2SS machineries have yet again unrelated folds, despite a common function. It is striking that a common complex function, such as targeting and assembling an outer membrane multimeric channel, can be performed by proteins with entirely different folds. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Micro-aerial vehicle type wall-climbing robot mechanism for structural health monitoring

    Science.gov (United States)

    Shin, Jae-Uk; Kim, Donghoon; Kim, Jong-Heon; Myung, Hyun

    2013-04-01

    Currently, the maintenance or inspection of large structures is labor-intensive, so it has a problem of the large cost due to the staffing professionals and the risk for hard to reach areas. To solve the problem, the needs of wall-climbing robot are emerged. Infra-based wall-climbing robots to maintain an outer wall of building have high payload and safety. However, the infrastructure for the robot must be equipped on the target structure and the infrastructure isn't preferred by the architects since it can injure the exterior of the structure. These are the reasons of why the infra-based wall-climbing robot is avoided. In case of the non-infra-based wall-climbing robot, it is researched to overcome the aforementioned problems. However, most of the technologies are in the laboratory level since the payload, safety and maneuverability are not satisfactory. For this reason, aerial vehicle type wall-climbing robot is researched. It is a flying possible wallclimbing robot based on a quadrotor. It is a famous aerial vehicle robot using four rotors to make a thrust for flying. This wall-climbing robot can stick to a vertical wall using the thrust. After sticking to the wall, it can move with four wheels installed on the robot. As a result, it has high maneuverability and safety since it can restore the position to the wall even if it is detached from the wall by unexpected disturbance while climbing the wall. The feasibility of the main concept was verified through simulations and experiments using a prototype.

  15. Structural and electrochemical characterisation of [Pd(salen)]-type conducting polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, J. [REQUIMTE, Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); Tedim, J. [Department of Chemistry, University of Leicester, Leicester LE1 7 RH (United Kingdom); Biernacki, K.; Magalhaes, A.L. [REQUIMTE, Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); Gurman, S.J. [Department of Physics, University of Leicester, Leicester LE1 7 RH (United Kingdom); Freire, C., E-mail: acfreire@fc.up.p [REQUIMTE, Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); Hillman, A.R., E-mail: arh7@le.ac.u [Department of Chemistry, University of Leicester, Leicester LE1 7 RH (United Kingdom)

    2010-11-01

    The oxidative polymerisation of four structurally-related [Pd(salen)] complexes and characterisation of the resulting polymeric films by cyclic voltammetry (CV), UV-visible transmission spectroscopy, X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) is reported. The voltammetric technique gives insight into the electrochemical properties of the polymeric films whereas UV-visible spectroscopy is used to characterise the electronic structure of Pd electroactive films, of particular relevance to the type of charge carriers. X-ray techniques (supported by density functional theory, DFT) provide information related to composition and structural features of [Pd(salen)] precursors and the resulting polymers. Characterisation of poly[Pd(salen)] films shows that the electrochemical response of these supramolecular systems is ligand-based and dependent upon substituents in the diimine bridge and aldehyde moieties. XAS measurements near the Pd K-edge demonstrate that polymerisation of the Pd complexes does not change the coordination sphere of the Pd centre; this is consistent with the coupling of monomers units via phenyl rings. As further evidence of ligand-based electrochemical responses, polymer doping does not impart any changes at the Pd centre or its coordination sphere. Compositional analysis by XPS confirms that C: Pd, N: Pd and O: Pd surface atomic ratios do not change significantly from monomer to undoped or doped polymer, except for small variations associated with incorporation of electrolyte and solvent upon polymerisation and polymer oxidation. Overall, the data provide a picture of a polyaromatic delocalised electroactive system, in which the metal atom plays a templating (rather than electroactive) role.

  16. Cryoelectron microscopy analysis of the structural changes associated with human rhinovirus type 14 uncoating.

    Science.gov (United States)

    Hewat, Elizabeth A; Blaas, Dieter

    2004-03-01

    Release of the human rhinovirus (HRV) genome into the cytoplasm of the cell involves a concerted structural modification of the viral capsid. The intracellular adhesion molecule 1 (ICAM-1) cellular receptor of the major-group HRVs and the low-density lipoprotein (LDL) receptor of the minor-group HRVs have different nonoverlapping binding sites. While ICAM-1 binding catalyzes uncoating, LDL receptor binding does not. Uncoating of minor-group HRVs is initiated by the low pH of late endosomes. We have studied the conformational changes concomitant with uncoating in the major-group HRV14 and compared them with previous results for the minor-group HRV2. The structure of empty HRV14 was determined by cryoelectron microscopy, and the atomic structure of native HRV14 was used to examine the conformational changes of the capsid and its constituent viral proteins. For both HRV2 and HRV14, the transformation from full to empty capsid involves an overall 4% expansion and an iris type of movement of viral protein VP1 to open up a 10-A-diameter channel on the fivefold axis to allow exit of the RNA genome. The beta-cylinders formed by the N termini of the VP3 molecules inside the capsid on the fivefold axis all open up in HRV2, but we propose that only one opens up in HRV14. The release of VP4 is less efficient in HRV14 than in HRV2, and the N termini of VP1 may exit at different points. The N-terminal loop of VP2 is modified in both viruses, probably to detach the RNA, but it bends only inwards in HRV2.

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

    Science.gov (United States)

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

    2013-06-01

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

  18. The structure of TeV-bright shell-type supernova remnants

    Science.gov (United States)

    Yang, Chuyuan; Liu, Siming; Fang, Jun; Li, Hui

    2015-01-01

    Aims: Two-dimensional magnetohydrodynamic (MHD) simulations are used to model the emission properties of TeV-bright shell-type supernova remnants (SNRs) and to explore their nature. Methods: In the leptonic scenario for the TeV emission, the γ-ray emission is produced via inverse Compton scattering of background soft photons by high-energy electrons accelerated by the shocks of the SNRs. In a previous paper, we showed that since the energy densities of the cosmic microwave background radiation and that of the IR/optical background photons are much higher than that of the photons produced by the same high-energy electrons via the synchrotron process, the observed correlation between X-ray and TeV brightness of SNR RX J1713.7-3946 can be readily explained with the assumption that the energy density of relativistic electrons is proportional to that of the magnetic field. The TeV emissivity is therefore proportional to the magnetic field energy density and MHD simulations can be used to model the TeV structure of such remnants directly. Two-dimensional MHD simulations for SNRs are then performed under the assumption that the ambient interstellar medium is turbulent with the magnetic field and density fluctuations, following a Kolmogorov-like power-law spectrum. Results: (1) As expected, these simulations confirm early 1D and 2D modelings of these sources, namely the hydrodynamical evolution of the shock waves and amplification of magnetic field by Rayleigh-Taylor convective flows and by shocks propagating in a turbulent medium; (2) we reproduce rather complex morphological structure for γ-rays, for example, the bright thin rim and significant asymmetry, suggesting intrinsic variations of the source morphology not related to the structure of the progenitor and environment; and (3) the observed radial profile of several remnants are well reproduced with an ambient medium density of 0.1-1 cm-3. An even lower ambient density leads to a sharper drop of the TeV brightness

  19. Itinerant type many-body theories for photo-induced structural phase transitions

    Science.gov (United States)

    Nasu, Keiichiro

    2004-09-01

    Itinerant type quantum many-body theories for photo-induced structural phase transitions (PSPTs) are reviewed in close connection with various recent experimental results related to this new optical phenomenon. There are two key concepts: the hidden multi-stability of the ground state, and the proliferations of optically excited states. Taking the ionic (I) rarr neutral (N) phase transition in the organic charge transfer (CT) crystal, TTF-CA, as a typical example for this type of transition, we, at first, theoretically show an adiabatic path which starts from CT excitons in the I-phase, but finally reaches an N-domain with a macroscopic size. In connection with this I-N transition, the concept of the initial condition sensitivity is also developed so as to clarify experimentally observed nonlinear characteristics of this material. In the next, using a more simplified model for the many-exciton system, we theoretically study the early time quantum dynamics of the exciton proliferation, which finally results in the formation of a domain with a large number of excitons. For this purpose, we derive a stepwise iterative equation to describe the exciton proliferation, and clarify the origin of the initial condition sensitivity. Possible differences between a photo-induced nonequilibrium phase and an equilibrium phase at high temperatures are also clarified from general and conceptional points of view, in connection with recent experiments on the photo-induced phase transition in an organo-metallic complex crystal. It will be shown that the photo-induced phase can make a new interaction appear as a broken symmetry only in this phase, even when this interaction is almost completely hidden in all the equilibrium phases, such as the ground state and other high-temperature phases. The relation between the photo-induced nonequilibrium phase and the hysteresis induced nonequilibrium one is also qualitatively discussed. We will be concerned with a macroscopic parity violation

  20. Itinerant type many-body theories for photo-induced structural phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Nasu, Keiichiro [Solid State Theory Division, Institute of Materials Structure Science, KEK, Graduate University for Advanced Study, 1-1, Oho, Tsukuba, Ibaraki, 305-0801 (Japan)

    2004-09-01

    Itinerant type quantum many-body theories for photo-induced structural phase transitions (PSPTs) are reviewed in close connection with various recent experimental results related to this new optical phenomenon. There are two key concepts: the hidden multi-stability of the ground state, and the proliferations of optically excited states. Taking the ionic (I) {yields} neutral (N) phase transition in the organic charge transfer (CT) crystal, TTF-CA, as a typical example for this type of transition, we, at first, theoretically show an adiabatic path which starts from CT excitons in the I-phase, but finally reaches an N-domain with a macroscopic size. In connection with this I-N transition, the concept of the initial condition sensitivity is also developed so as to clarify experimentally observed nonlinear characteristics of this material. In the next, using a more simplified model for the many-exciton system, we theoretically study the early time quantum dynamics of the exciton proliferation, which finally results in the formation of a domain with a large number of excitons. For this purpose, we derive a stepwise iterative equation to describe the exciton proliferation, and clarify the origin of the initial condition sensitivity. Possible differences between a photo-induced nonequilibrium phase and an equilibrium phase at high temperatures are also clarified from general and conceptional points of view, in connection with recent experiments on the photo-induced phase transition in an organo-metallic complex crystal. It will be shown that the photo-induced phase can make a new interaction appear as a broken symmetry only in this phase, even when this interaction is almost completely hidden in all the equilibrium phases, such as the ground state and other high-temperature phases. The relation between the photo-induced nonequilibrium phase and the hysteresis induced nonequilibrium one is also qualitatively discussed. We will be concerned with a macroscopic parity

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

    Directory of Open Access Journals (Sweden)

    Shlomit Farkash-Amar

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

  2. Chemical Defects, Electronic Structure, and Transport in N-type and P-type Organic Semiconductors: First Principles Theory

    Science.gov (United States)

    2012-11-29

    boundaries. A paper describing the work was published in Nature Materials. {J. Rivnay, L.H. Jimison, J. E. Northrup, M. F. Toney, R. Noriega , S. Lu, T. J...Switzerland.[4] [1] J. Rivnay, R. Noriega , J. E. Northrup, R. J. Kline, M. F. Toney, and A. Salleo, Structural origin of gap states in semicrystalline...1] J. Rivnay, L.H. Jimison, J. E. Northrup, M. F. Toney, R. Noriega , S. Lu, T. J. Marks, A, Facchetti, and A. Salleo, Large modulation of

  3. Effect of Mg substitution on crystal structure and hydrogenation of Ce2Ni7-type Pr2Ni7

    Science.gov (United States)

    Iwase, Kenji; Mori, Kazuhiro; Terashita, Naoyoshi; Tashiro, Suguru; Suzuki, Tetsuya

    2017-03-01

    The effect of Pr being substituted by Mg in Pr2Ni7 with a Ce2Ni7-type structure was investigated by X-ray diffraction (XRD) and pressure-composition (P-C) isotherm measurements. The maximum hydrogen capacity of Pr2Ni7 reached 1.24 H/M in the first absorption process. However, 0.61 H/M hydrogen remained in the sample after the first desorption and the reversible hydrogen capacity decreased to 0.63 H/M. Severe peak broadening was observed in the XRD profile of Pr2Ni7H5.4 after the first P-C isotherm cycle. The metal sublattice of Pr2Ni7H5.4 is deformed and changes from the Ce2Ni7-type structure to a lower symmetry during hydrogenation, with no detection of an amorphous phase. Pr1.5Mg0.5Ni7 consists of two phases: 80% Gd2Co7-type and 20% PuNi3-type phases. Mg substitution leads to the relative stability of the Gd2Co7-type and PuNi3-type structures. The Gd2Co7-type and PuNi3-type structures are retained after the P-C isotherm. The reversible hydrogen capacity reached 1.05 H/M. The structural change during the hydrogen absorption-desorption cycle and the hydrogenation characteristics are changed by Mg atoms replacing Pr in the MgZn2-type cell.

  4. Three types of mycolic acid from Mycobacterium tuberculosis Brévanne: implications for structure-function relationships in pathogenesis.

    Science.gov (United States)

    Toubiana, R; Berlan, J; Sato, H; Strain, M

    1979-01-01

    Saponification of the chloroform-soluble wax from Mycobacterium tuberculosis Brévanne led to the isolation of three classes of mycolic acid containing characteristic functional groups along the methylene backbone: type alpha (two cyclopropane rings); type beta (methoxyl, methyl, and cyclopropane); and type gamma (ketone, methyl, and cyclopropane). The structures of these acids were elucidated principally by mass spectrometry. The high mass region of the keto mycolate is presented showing the meromycolal and molecular ion regions. This is first time a molecular peak for this mycolic acid has been reported. The structure of the keto mycolate was further substantiated by study of the mass spectral fragmentation of its dithioketal derivative. Within each type of acid, a series of homologs was encountered, varying according to the number of methylene units in the backbone chain. Chromatographic and infrared spectrophotometric evidence is presented for the alkali-induced isomerization of the three types of mycolates. Images PMID:110779

  5. Electronic and magnetic properties of Cr-Mn-Ni-Al compound with LiMgPdSb-type structure

    Science.gov (United States)

    Wang, L. Y.; Wang, X. T.; Guo, R. K.; Lin, T. T.; Liu, G. D.

    2016-10-01

    We investigate the electronic and magnetic properties of Cr-Mn-Ni-Al compound with a LiMgPdSn-type structure in three different atomic arrangement configurations (AAC) by using the first-principles calculations. It was found that Cr-Mn-Ni-Al compound with type I AAC exhibits a spin-gapless semiconductive characteristic. The type II AAC is the most stable one and exhibits an especial band structure where the Fermi level slightly crosses the top of the valence bands in spin-up channel and the bottom of conductive bands in spin-down channel, which leads to the electronic transport with the spin-resolved carrier type. The Cr-Mn-Ni-Al compound shows an ordinary metallic behavior in type III AAC. The three nonequivalent atomic arrangement configurations of Cr-Mn-Ni-Al are all in ferromagnetic ground state under their equilibrium lattice parameters.

  6. Crystal structures of cristobalite-type and coesite-type PON redetermined on the basis of single-crystal X-ray diffraction data

    Directory of Open Access Journals (Sweden)

    Maxim Bykov

    2015-11-01

    Full Text Available Hitherto, phosphorus oxonitride (PON could not be obtained in the form of single crystals and only powder diffraction experiments were feasible for structure studies. In the present work we have synthesized two polymorphs of phosphorus oxonitride, cristobalite-type (cri-PON and coesite-type (coe-PON, in the form of single crystals and reinvestigated their crystal structures by means of in house and synchrotron single-crystal X-ray diffraction. The crystal structures of cri-PON and coe-PON are built from PO2N2 tetrahedral units, each with a statistical distribution of oxygen and nitrogen atoms. The crystal structure of the coe-PON phase has the space group C2/c with seven atomic sites in the asymmetric unit [two P and three (N,O sites on general positions, one (N,O site on an inversion centre and one (N,O site on a twofold rotation axis], while the cri-PON phase possesses tetragonal I-42d symmetry with two independent atoms in the asymmetric unit [the P atom on a fourfold inversion axis and the (N,O site on a twofold rotation axis]. In comparison with previous structure determinations from powder data, all atoms were refined with anisotropic displacement parameters, leading to higher precision in terms of bond lengths and angles.

  7. Crystal structures of cristobalite-type and coesite-type PON redetermined on the basis of single-crystal X-ray diffraction data.

    Science.gov (United States)

    Bykov, Maxim; Bykova, Elena; Dyadkin, Vadim; Baumann, Dominik; Schnick, Wolfgang; Dubrovinsky, Leonid; Dubrovinskaia, Natalia

    2015-11-01

    Hitherto, phospho-rus oxonitride (PON) could not be obtained in the form of single crystals and only powder diffraction experiments were feasible for structure studies. In the present work we have synthesized two polymorphs of phospho-rus oxonitride, cristobalite-type (cri-PON) and coesite-type (coe-PON), in the form of single crystals and reinvestigated their crystal structures by means of in house and synchrotron single-crystal X-ray diffraction. The crystal structures of cri-PON and coe-PON are built from PO2N2 tetra-hedral units, each with a statistical distribution of oxygen and nitro-gen atoms. The crystal structure of the coe-PON phase has the space group C2/c with seven atomic sites in the asymmetric unit [two P and three (N,O) sites on general positions, one (N,O) site on an inversion centre and one (N,O) site on a twofold rotation axis], while the cri-PON phase possesses tetra-gonal I-42d symmetry with two independent atoms in the asymmetric unit [the P atom on a fourfold inversion axis and the (N,O) site on a twofold rotation axis]. In comparison with previous structure determinations from powder data, all atoms were refined with anisotropic displacement parameters, leading to higher precision in terms of bond lengths and angles.

  8. Multilocus typing and population structure of Cryptosporidium from children in Zaragoza, Spain.

    Science.gov (United States)

    Ramo, Ana; Quílez, Joaquín; Vergara-Castiblanco, Claudia; Monteagudo, Luis; Del Cacho, Emilio; Clavel, Antonio

    2015-04-01

    A multilocus typing approach with eight variable-number tandem-repeat (VNTR) loci and the GP60 gene was used to analyze the inter- and intra-species variation of 44 Cryptosporidium isolates from pediatric patients in Zaragoza city (NE, Spain). Restriction and sequence analyses of the SSU rRNA gene revealed that Cryptosporidium transmission is mostly anthroponotic in this area, with the predominance of Cryptosporidium hominis (n: 41) over Cryptosporidium parvum (n: 3). GP60 subtyping showed limited genetic diversity and four subtypes were identified, including IbA10G2 (n: 35), IaA24R3 (n: 6), IIaA15G1R1 (n: 1) and IIaA15G2R1 (n: 2). Five out of eight VNTR loci showed a discriminatory power higher than the GP60 gene, although each locus had a predominant allele exhibited by more than 50% of isolates. All but four alleles were associated to either C. hominis or C. parvum and linked alleles at different loci were found. Multilocus typing substantially increased the discriminatory power (Hunter-Gaston index: 0.807, 95% CI, 0.683-0.926) and revealed that genetic diversity is much higher than that reported by GP60 sequencing, since 17 multilocus subtypes (MLTs) were identified. Nearly half of the specimens were allocated to a single major MLT. However, no more than three specimens were allocated to each of the remaining MLTs. Both phylogenetic and population analyses revealed a population clustering of C. hominis according to the GP60 subtype, which indicates the robustness of this marker to differentiate genetic subpopulations. Subpopulations had an overall clonal genetic structure, although traces of genetic flow between them were also observed.

  9. The Structure-Function Relationships of Complement Receptor Type 2 (CR2; CD21).

    Science.gov (United States)

    Hannan, Jonathan Paul

    2016-01-01

    Human complement receptor type 2 (CR2; CD21) is a surface-associated glycoprotein which binds to a variety of endogenous ligands, including the complement component C3 fragments iC3b, C3dg and C3d, the low-affinity IgE receptor CD23, and the type I cytokine, interferon-alpha. CR2 links the innate complement-mediated immune response to pathogens and foreign antigens with the adaptive immune response by binding to C3d that is covalently attached to targets, and which results in a cell signalling phenomenon that lowers the threshold for B cell activation. Variations or deletions of the CR2 gene in humans, or the Cr2 gene in mice associate with a variety of autoimmune and inflammatory conditions. A number of infectious agents including Epstein-Barr virus (EBV), Human Immunodeficiency Virus (HIV) and prions also bind to CR2 either directly or indirectly by means of C3d-targeted immune complexes. In this review we discuss the interactions that CR2 undertakes with its best characterized ligands C3d, CD23 and the EBV gp350/220 envelope protein. To date only a single physiologically relevant complex of CR2 with one of its ligands, C3d, has been elucidated. By contrast, the interactions with CD23 and EBV gp350/220, while being important from physiologic and disease-associated standpoints, respectively, are only incompletely understood. A detailed knowledge of the structure-function relationships that CR2 undergoes with its ligands is necessary to understand the implications of using recombinant CR2 in therapeutic or imaging agents, or alternatively targeting CR2 to down-regulate the antibody mediated immune response in cases of autoimmunity.

  10. Moroccan Leishmania infantum: genetic diversity and population structure as revealed by multi-locus microsatellite typing.

    Directory of Open Access Journals (Sweden)

    Ahmad Amro

    Full Text Available Leishmania infantum causes Visceral and cutaneous leishmaniasis in northern Morocco. It predominantly affects children under 5 years with incidence of 150 cases/year. Genetic variability and population structure have been investigated for 33 strains isolated from infected dogs and humans in Morocco. A multilocus microsatellite typing (MLMT approach was used in which a MLMtype based on size variation in 14 independent microsatellite markers was compiled for each strain. MLMT profiles of 10 Tunisian, 10 Algerian and 21 European strains which belonged to zymodeme MON-1 and non-MON-1 according to multilocus enzyme electrophoresis (MLEE were included for comparison. A Bayesian model-based approach and phylogenetic analysis inferred two L.infantum sub-populations; Sub-population A consists of 13 Moroccan strains grouped with all European strains of MON-1 type; and sub-population B consists of 15 Moroccan strains grouped with the Tunisian and Algerian MON-1 strains. Theses sub-populations were significantly different from each other and from the Tunisian, Algerian and European non MON-1 strains which constructed one separate population. The presence of these two sub-populations co-existing in Moroccan endemics suggests multiple introduction of L. infantum from/to Morocco; (1 Introduction from/to the neighboring North African countries, (2 Introduction from/to the Europe. These scenarios are supported by the presence of sub-population B and sub-population A respectively. Gene flow was noticed between sub-populations A and B. Five strains showed mixed A/B genotypes indicating possible recombination between the two populations. MLMT has proven to be a powerful tool for eco-epidemiological and population genetic investigations of Leishmania.

  11. [Stability of the structure and antigenic determinants of adenovirus type 1 native hexon to proteases].

    Science.gov (United States)

    Kiseleva, E K; Khil'ko, S N; Grigor'ev, V G; Diachenko, N S; Vantsak, N P

    1986-08-01

    Hexon capsomers of human adenovirus type 1 (h1) labeled by iodine 125 were digested in a native state (trimers) by trypsin, chymotrypsin or papain, and the resulting hydrolysates were analyzed by SDS-PAGE. In each case, a discrete and temporally stable pattern of relatively large fragments was revealed. The degree of hexon polypeptide hydrolysis was maximal for papain, intermediate for chymotrypsin and minimal for trypsin, the largest fragments in the digest being 32, 40 and 80 kD, respectively. At room temperature, all the electrophoretically discernible hexon proteolytical fragments were held together in structures resembling intact hexon trimers and could be regarded as "hexon cores", of which papain hexon cores were the most stable during SDS-PAGE. Radioimmunoprecipitation analysis revealed a complete absence of native hexon antigenicity in thermodenaturated fragments of hexon protease digests, while native trypsin, chymotrypsin and papain hexon cores could be precipitated by hexon-specific antibodies. The immunoprecipitated material contained all of the hexon fragments found in appropriate hexon cores and retained the structure of the original cores. Trypsin, chymotrypsin and papain hexon cores were shown to possess at least part of native Ad h1 hexon antigenic determinants of each of the following specificities: species-specific (epsilon), cross-reactive with hexon of human adenoviruses (h3 and h6), simian adenovirus (sim 16), bovine adenoviruses (bos 3 and bos 7) and avian adenovirus (Aviadenovirus gal 1 or CELO). Thus, the full spectrum of known hexon antigenic determinants (species-specific to intergenus-crossreactive) is at least portly stable against protease attack of native hexon capsomers.

  12. Activation Induces Structural Changes in the Liganded Angiotensin II Type 1 Receptor*

    Science.gov (United States)

    Clément, Martin; Cabana, Jérôme; Holleran, Brian J.; Leduc, Richard; Guillemette, Gaétan; Lavigne, Pierre; Escher, Emanuel

    2009-01-01

    The octapeptide hormone angiotensin II (AngII) binds to and activates the human angiotensin II type 1 receptor (hAT1) of the G protein-coupled receptor class A family. Several activation mechanisms have been proposed for this family, but they have not yet been experimentally validated. We previously used the methionine proximity assay to show that 11 residues in transmembrane domain (TMD) III, VI, and VII of the hAT1 receptor reside in close proximity to the C-terminal residue of AngII. With the exception of a single change in TMD VI, the same contacts are present on N111G-hAT1, a constitutively active mutant; this N111G-hAT1 is a model for the active form of the receptor. In this study, two series of 53 individual methionine mutations were constructed in TMD I, II, IV, and V on both receptor forms. The mutants were photolabeled with a neutral antagonist, 125I-[Sar1,p-benzoyl-l-Phe8]AngII, and the resulting complexes were digested with cyanogen bromide. Although no new contacts were found for the hAT1 mutants, two were found in the constitutively active mutants, Phe-77 in TMD II and Asn-200 in TMD V. To our knowledge, this is the first time that a direct ligand contact with TMD II and TMD V has been reported. These contact point differences were used to identify the structural changes between the WT-hAT1 and N111G-hAT1 complexes through homology-based modeling and restrained molecular dynamics. The model generated revealed an important structural rearrangement of several TMDs from the basal to the activated form in the WT-hAT1 receptor. PMID:19635801

  13. The detailed crystal and electronic structures of the cotunnite-type ZrO2

    Science.gov (United States)

    Zhang, Yan; Duan, Li; Ji, Vincent

    2016-07-01

    The detailed crystal and orbital-decomposed electronic structures of cotunnite-type ZrO2 have been investigated by using the first-principles projector augmented wave (PAW) potential within the generalized gradient approximation as well as taking into account on-site Coulomb repulsive interaction (GGA+U). The optimized structure shows that the OI and OII anions are surrounded by an arbitrary tetrahedron of four Zr cations and an arbitrary pentahedron of five Zr cations, respectively, in turn, the Zr cation is surrounded by an arbitrary tetrakaidecahedron formed by nine oxygen ligands. Although one more Zr cation is coordinated to OII, the larger bond lengths between OII and its adjacent five Zr cations (dOII-Zr) than those between OI and its adjacent four Zr cations (dOI-Zr) makes density of states (DOS) of s and three p (px , py and pz) states of the OII anion driving down in lower energy region and driving up in higher energy region. No crystal-field splitting is observed between three p (px , py and pz) states of anions OI and OII (between three p (px , py and pz) states and five d (dxy , dyz , dxz , dz2 and dx2-y2) states of cation Zr) is resulted from the arrangements of the surrounding cations (anions) do not have any symmetry. The additional covalent character upon Zr-O ionic bonds is attributed to the hybridization of itinerant Zr(5s) and less filled Zr(4d) states to the separated O(2s) and O(2p) states.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Babelot, Carole

    2013-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Babelot, Carole

    2013-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-15

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

  18. Structural basis of specific inhibition of tissue-type plasminogen activator by plasminogen activators inhibitor-1

    Science.gov (United States)

    Gong, Lihu; Liu, Min; Zeng, Tu; Shi, Xiaoli; Yuan, Cai; Andreasen, Peter A.; Huang, Mingdong

    2016-01-01

    Thrombosis is a leading cause of death worldwide [1]. Recombinant tissue-type plasminogen activator (tPA) is the FDA-approved thrombolytic drug for ischemic strokes, myocardial infarction and pulmonary embolism. tPA is a multi-domain serine protease of the trypsin-family [2] and catalyses the critical step in fibrinolysis [3], converting the zymogen plasminogen to the active serine protease plasmin, which degrades the fibrin network of thrombi and blood clots. tPA is rapidly inactivated by endogenous plasminogen activators inhibitor-1 (PAI-1) [4] (Fig. 1). Engineering on tPA to reduce its inhibition by PAI-1 without compromising its thrombolytic effect is a continuous effort [5]. Tenecteplase (TNK-tPA) is a newer generation of tPA variant showing slower inhibition by PAI-1 [6]. Extensive studies to understand the molecular interactions between tPA and PAI-1 have been carried out [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], however, the precise details at atomic resolution remain unknown. We report the crystal structure of tPA·PAI-1 complex here. The methods required to achieve these data include: (1) recombinant expression and purification of a PAI-1 variant (14-1B) containing four mutations (N150H, K154T, Q319L, and M354I), and a tPA serine protease domain (tPA-SPD) variant with three mutations (C122A, N173Q, and S195A, in the chymotrypsin numbering) [19]; (2) formation of a tPA-SPD·PAI-1 Michaëlis complex in vitro [19]; and (3) solving the three-dimensional structure for this complex by X-ray crystallography [deposited in the PDB database as 5BRR]. The data explain the specificity of PAI-1 for tPA and uPA [19], [20], and provide structural basis to design newer generation of PAI-1-resistant tPA variants as thrombolytic agents [19]. PMID:26909366

  19. Enhanced power factor and reduced Lorenz number in the Wiedemann-Franz law due to pudding mold type band structures

    Science.gov (United States)

    Usui, Hidetomo; Kuroki, Kazuhiko

    2017-04-01

    We study the relationship between the shape of the electronic band structure and the thermoelectric properties. In order to study the band shape dependence of the thermoelectric properties generally, we first adopt models with band structures having the dispersion E ( k ) ˜ | k | n with n = 2, 4, and 6. We consider one-, two-, and three-dimensional systems and calculate the thermoelectric properties using the Boltzmann equation approach within the constant quasi-particle lifetime approximation. n = 2 corresponds to the usual parabolic band structure, while the band shape for n = 4 and 6 has a flat portion at the band edge, so that the density of states diverges at the bottom of the band. We call this kind of band structure the "pudding mold type band". n ≥ 4 belong to the pudding mold type band, but since the density of states diverges even for n = 2 in the one dimensional system, this is also categorized as the pudding mold type. Due to the large density of states and the rapid change of the group velocity around the band edge, the spectral conductivity of the pudding mold type band structures becomes larger than that of the usual parabolic band structures. It is found that the pudding mold type band has a coexistence of a large Seebeck coefficient and a large electric conductivity and a small Lorenz number in the Wiedemann-Franz law due to the specific band shape. We also find that the low dimensionality of the band structure can contribute to large electronic conductivity and hence a small Lorenz number. We conclude that the pudding mold type band, especially in low dimensional systems, can enhance not only the power factor but also the dimensionless figure of merit due to stronger reduction of the Lorenz number.

  20. Local structure and electronic properties of BaTaO2N with perovskite-type structure

    NARCIS (Netherlands)

    Fang, C.M.; Wijs, G.A. de; Orhan, E.; With, G. de; de Groot, R.A.; Hintzen, H.T.; Marchand, R.

    2003-01-01

    First-principles calculation based on density-functional theory in the pseudo-potential approach have been performed for the total energy and crystal structure of BaTaO2N. The calculations indicate a random occupation of the anionic positions by O and N in a cubic structure, in agreement with neutro

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

    CERN Document Server

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

    2017-01-01

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

  2. Structure and Kinematics of Early-Type Galaxies from Integral-Field Spectroscopy

    CERN Document Server

    Cappellari, Michele

    2016-01-01

    Observations of galaxy isophotes, longs-slit kinematics and high-resolution photometry suggested a possible dichotomy between two distinct classes of E galaxies. But these methods are expensive for large galaxy samples. Instead, integral-field spectroscopic can efficiently recognize the shape, dynamics and stellar population of complete samples of early-type galaxies (ETGs). These studies showed that the two main classes, the fast and slow rotators, can be separated using stellar kinematics. We showed there is a dichotomy in the dynamics of the two classes. The slow rotators are weakly triaxial and dominate above $M_{\\rm crit}\\approx2\\times10^{11} M_\\odot$. Below $M_{\\rm crit}$, the structure of fast rotators parallels that of spiral galaxies. There is a smooth sequence along which, the metals content, the enhancement in $\\alpha$-elements, and the "weight" of the stellar initial mass function, all increase with the CENTRAL mass density slope, or bulge mass fraction, while the molecular gas fraction correspond...

  3. Synthesis and characterization of nano-structured perovskite type neodymium orthoferrite NdFeO3

    Directory of Open Access Journals (Sweden)

    Mostafa Yousefi

    2017-01-01

    Full Text Available In this investigation, neodymium orthoferrite (NdFeO3 nanoparticles has been synthesized through ultrasonic method in the presence of octanoic acid as surfactant. This method comparing to the other methods is very fast and it does not need high temperatures during the reaction. The spherical NdFeO3 nanoparticles with an average particles size of about 40 nm can be obtained at a relatively high calcination temperature of 800 °C for 4 h. Also, product obtained by this method are uniform in both morphology and particles size. The phase composition, morphology, lattice parameters and size of particles in these product are characterized by Fourier transform infrared (FT-IR spectroscopy, X-ray diffraction (XRD scanning electron microscopy (SEM and energy dispersive X-ray spectrometer (EDX. The XRD analysis reveals only the pattern corresponding to perovskite type NdFeO3 which crystallizes in the orthorhombic structure. Energy dispersive X-ray analysis confirms the elemental compositions of the synthesized material.

  4. Nanoscale calibration of n-type ZnO staircase structures by scanning capacitance microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L., E-mail: lin.wang@insa-lyon.fr; Laurent, J.; Brémond, G. [Institut des Nanotechnologies de Lyon (INL), Université de Lyon, CNRS UMR 5270, INSA Lyon, 7 Avenue Jean Capelle, 69621 Villeurbanne (France); Chauveau, J. M. [Centre de Recherche sur l' Hétéro-Epitaxie et ses Applications (CRHEA), CNRS UPR10, rue Bernard Grégory, 06560 Valbonne Sophia Antipolis (France); Physics Department, University of Nice Sophia Antipolis (UNS), Parc Valrose, 06103 Nice (France); Sallet, V.; Jomard, F. [Groupe d' étude de la matière condensée (GEMaC), CNRS - Université de Versailles St Quentin en Yvelines, Université Paris-Saclay, 45 Avenue des Etats Unis, 78035 Versailles (France)

    2015-11-09

    Cross-sectional scanning capacitance microscopy (SCM) was performed on n-type ZnO multi-layer structures homoepitaxially grown by molecular beam epitaxy method. Highly contrasted SCM signals were obtained between the ZnO layers with different Ga densities. Through comparison with dopant depth profiles from secondary ion mass spectroscopy measurement, it is demonstrated that SCM is able to distinguish carrier concentrations at all levels of the samples (from 2 × 10{sup 17 }cm{sup −3} to 3 × 10{sup 20 }cm{sup −3}). The good agreement of the results from the two techniques indicates that SCM can be a useful tool for two dimensional carrier profiling at nanoscale for ZnO nanostructure development. As an example, residual carrier concentration inside the non-intentionally doped buffer layer was estimated to be around 2 × 10{sup 16 }cm{sup −3} through calibration analysis.

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

    Directory of Open Access Journals (Sweden)

    Hui Zhang

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

  6. On SYM theory and all order Bulk Singularity Structures of BPS Strings in type II theory

    CERN Document Server

    Hatefi, Ehsan

    2016-01-01

    The complete form of the S-matrix elements of three supersymmetric Yang-Mills (SYM), namely a transverse scalar field, two world volume gauge fields and a Potential $C_{n-1}$ Ramond-Ramond (RR) form field has been investigated. Basically, in order to find out an infinite number of $t,s, (t+s+u)$ channel bulk singularity structures of that particular mixed closed-open amplitude, we employ all the conformal field theory techniques to $$ and explore all the entire correlation functions as well as all order $\\alpha'$ contact interactions of these SYM couplings. The comparisons with the other symmetric analysis $$ and $$ are also carried out in detail. Various couplings from pull-Back of branes, Myers terms and several generalized Bianchi identities should be taken into account to be able to reconstruct all order $\\alpha'$ bulk singularities of type IIB(IIA) superstring theory. Finally, we make a comment on how to derive without any ambiguity all order $\\alpha'$ contact terms of those elements of the S-matrix that...

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

    Science.gov (United States)

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

    2015-01-01

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

  8. Structures and antioxidant and intestinal disaccharidase inhibitory activities of A-type proanthocyanidins from peanut skin.

    Science.gov (United States)

    Zhang, Huiwen; Yerigui; Yang, Yumei; Ma, Chaomei

    2013-09-18

    Nine compounds including a new A-type proanthocyanidin trimer, epicatechin-(2β→O→7,4β→8)-[catechin-(6→4β)]-epicatechin (8), and a known trimer, epicatechin-(4β→8)-epicatechin-(2β→O→7,4β→8)-catechin (9), being reported for peanut skin for the first time, were isolated and purified. Their structures were determined by spectroscopic methods and by degradation reactions with L-cysteine in acidic conditions. The DPPH radical scavenging activity and the inhibitory activity on maltase and sucrase of the isolated compounds were investigated. All compounds showed strong DPPH scavenging activities (EC₅₀ < 20 μg/mL). Compound 8 showed the strongest inhibitory activity on maltase with an IC₅₀ value of 0.088 mg/mL, while compound 9 exhibited the strongest inhibition on sucrase with an IC₅₀ value of 0.091 mg/mL.

  9. Synthesis, structure and applications of [cis-dioxomolybdenum(VI)-(ONO)] type complexes

    Indian Academy of Sciences (India)

    Rajan Deepan Chakravarthy; Dillip Kumar Chand

    2011-03-01

    Oxo-molybdenum chemistry is of great interest since such units are found in the active sites of a majority of molybdo-enzymes. In order to mimic the biological systems, a number of oxo-molybdenum complexes have been synthesised and studied. This review describes synthesis, structure and applications of oxomolybdenum complexes particularly cis-MoO2(L)(D) where L stands for a dianionic tridentate ONO ligand and D for a donor solvent molecule/monodentate ligand. The ligand moieties are derived from Schiff base, hydrazide Schiff base and other related tridentate ligands L(H)2. The coordination geometry around the Mo center in these complexes can be best described as a distorted octahedron in which the ONO-tridentate ligand occupies meridional position with two anionic oxygen donors mutually trans and are cis to the oxygen centers of the cis-dioxo group. Mostly the applications of cis-MoO2-(ONO) type complexes seen in literature are oxo transfer reactions like epoxidation, sulfoxidation and phosphine oxidation reactions.

  10. The structure of TeV-bright shell-type supernova remnants

    CERN Document Server

    Yang, Chuyuan; Fang, Jun; Li, Hui

    2014-01-01

    Aims. Two-dimensional MHD simulations are used to model the emission properties of TeV-bright shell-type supernova remnants (SNRs) and to explore their nature. Methods. In the leptonic scenario for the TeV emission, the $\\gamma$-ray emission is produced via Inverse Compton scattering of background soft photons by high-energy electrons accelerated by the shocks of the SNRs. The TeV emissivity is proportional to the magnetic field energy density and MHD simulations can be used to model the TeV structure of such remnants directly. 2D MHD simulations for SNRs are then performed under the assumption that the ambient interstellar medium is turbulent with the magnetic field and density fluctuations following a Kolmogorov-like power-law spectrum. Results. (1) As expected, these simulations confirm early 1D and 2D modelings of these sources, namely the hydrodynamical evolution of the shock waves and amplification of magnetic field by Rayleigh-Taylor convective flows and by shocks propagating in a turbulent medium; (2)...

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

    Directory of Open Access Journals (Sweden)

    T. Abe

    2014-01-01

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

  12. Plausible molecular and crystal structures of chitosan/HI type II salt.

    Science.gov (United States)

    Lertworasirikul, Amornrat; Noguchi, Keiichi; Ogawa, Kozo; Okuyama, Kenji

    2004-03-15

    Chitosan/HI type II salt prepared from crab tendon was investigated by X-ray fiber diffraction. Two polymer chains and 16 iodide ions (I(-)) crystallized in a tetragonal unit cell with lattice parameters of a = b = 10.68(3), c (fiber axis) = 40.77(13) A, and a space group P4(1). Chitosan forms a fourfold helix with a 40.77 A fiber period having a disaccharide as the helical asymmetric unit. One of the O-3... O-5 intramolecular hydrogen bonds at the glycosidic linkage is weakened by interacting with iodide ions, which seems to cause the polymer to take the 4/1-helical symmetry rather than the extended 2/1-helix. The plausible orientations of two O-6 atoms in the helical asymmetric unit were found to be gt and gg. Two chains are running through at the corner and the center of the unit cell along the c-axis. They are linked by hydrogen bonds between N-21 and O-61 atoms. Two out of four independent iodide ions are packed between the corner chains while the other two are packed between the corner and center chains when viewing through the ab-plane. The crystal structure of the salt is stabilized by hydrogen bonds between these iodide ions and N-21, N-22, O-32, O-61, O-62 of the polymer chains.

  13. Structural characterization and anti-tumor effects of an inulin-type fructan from Atractylodes chinensis.

    Science.gov (United States)

    Xu, Jing; Chen, Dan; Liu, Chang; Wu, Xiong-Zhi; Dong, Cai-Xia; Zhou, Jing

    2016-01-01

    A fructan (ACPS-1) with a molecular weight of 11.2 kDa was isolated from Atractylodes chinensis rhizome and characterized by chemical derivatization, HPLC, GC-MS, FT-IR, and NMR. Structural analyses revealed that ACPS-1 is predominately composed of fructose and a small amount of glucose and a polymerization degree of about 53. The fructan was deduced to be an inulin-type fructan containing a linear backbone composed of (2→1)-linked β-d-Fruf residues. The in vitro antitumor activity of ACPS-1 was evaluated on four human cancer cell lines, including a cervical cancer cell line (Hela), two liver hepatocellular carcinoma cell lines (HepG2 and 7721), and an ovarian carcinoma cell line (Skov3). Results showed that ACPS-1 could significantly inhibit Hela, HepG2, and 7721 cell proliferation, especially HepG2, for which the fructan showed a proliferative inhibition rate as high as 87.40%. This result suggests that ACPS-1 may have anticancer potentiality against hepatocellular carcinoma and warrants further investigation.

  14. Formation, stability and crystal structure of mullite-type Al6-xBxO9

    Science.gov (United States)

    Hoffmann, K.; Hooper, T. J. N.; Murshed, M. M.; Dolotko, O.; Révay, Z.; Senyshyn, A.; Schneider, H.; Hanna, J. V.; Gesing, Th. M.; Fischer, R. X.

    2016-11-01

    Mullite-type Al6-xBxO9 compounds were studied by means of powder diffraction and spectroscopic methods. The backbones of this structure are chains of edge-connected AlO6 octahedra crosslinked by AlO- and BO-polyhedra. Rietveld refinements show that the a and b lattice parameters can be well resolved, thus representing an orthorhombic metric. A continuous decrease of the lattice parameters most pronounced in c-direction indicates a solid solution for Al6-xBxO9 with 1.09≤x≤2. A preference of boron in 3-fold coordination is confirmed by 11B MAS NMR spectroscopy and Fourier calculations based on neutron diffraction data collected at 4 K. Distance Least Squares modeling was performed to simulate a local geometry avoiding long B-O distances linking two octahedral chains by planar BO3 groups yielding split positions for the oxygen atoms and a strong distortion in the octahedral chains. The lattice thermal expansion was calculated using the Grüneisen first-order equation of state Debye-Einstein-Anharmonicity model.

  15. Crystal structure of Legionella pneumophila type IV secretion system effector LegAS4.

    Science.gov (United States)

    Son, Jonghyeon; Jo, Chang Hwa; Murugan, Ravichandran N; Bang, Jeong Kyu; Hwang, Kwang Yeon; Lee, Woo Cheol

    2015-10-02

    The SET domain of LegAS4, a type IV secretion system effector of Legionella pneumophila, is a eukaryotic protein motif involved in histone methylation and epigenetic modulation. The SET domain of LegAS4 is involved in the modification of Lys4 of histone H3 (H3K4) in the nucleolus of the host cell, thereby enhancing heterochromatic rDNA transcription. Moreover, LegAS4 contains an ankyrin repeat domain of unknown function at its C-terminal region. Here, we report the crystal structure of LegAS4 in complex with S-adenosyl-l-methionine (SAM). Our data indicate that the ankyrin repeats interact extensively with the SET domain, especially with the SAM-binding amino acids, through conserved residues. Conserved surface analysis marks Glu159, Glu203, and Glu206 on the SET domain serve as candidate residues involved in interaction with the positively charged histone tail. Conserved surface residues on the ankyrin repeat domain surround a small pocket, which is suspected to serve as a binding site for an unknown ligand.

  16. Depleted cores, multi-component fits, and structural parameter relations for luminous early-type galaxies

    CERN Document Server

    Dullo, Bililign T

    2013-01-01

    New surface brightness profiles from 26 early-type galaxies with partially depleted cores have been extracted from the full radial extent of Hubble Space Telescope images, giving us a total sample of 31 such core-Sersic galaxies. We have carefully quantified the radial stellar distributions of the elliptical galaxies using the core-Sersic model whereas for the lenticular galaxies a core-Sersic bulge plus an exponential disc model gives the best representation. We additionally caution about the excessive use of multiple Sersic functions for decomposing galaxies. The structural parameters obtained from our fitted models are used to update several `central' as well as `global' galaxy scaling relations. We find near-linear relations between the break radius R_b and the spheroid luminosity L such that R_b ~ L^(1.13 +/- 0.13), and with the supermassive black hole mass M_BH such that R_b ~ M_BH^(0.83+/- 0.21). This is internally consistent with the notion that major, dry mergers add the stellar and black hole mass i...

  17. Structural tailoring effects on the magnetic behavior of symmetric and asymmetric cubane-type Ni complexes.

    Science.gov (United States)

    Ponomaryov, Alexey N; Kim, Namseok; Hwang, Jaewon; Nojiri, Hiroyuki; van Tol, Johan; Ozarowski, Andrew; Park, Jena; Jang, Zeehoon; Suh, Byoungjin; Yoon, Sungho; Choi, Kwang-Yong

    2013-06-01

    Using two kinds of carboxylate ligands with small but significant differences in steric size, symmetric and asymmetric Fe(II) and Ni(II) cubanes have been synthesized in a controlled fashion. Fast sweeping pulsed field measurements showed magnetization hysteresis loops for two cubane-type molecular complexes, [Ni4(μ-OMe)4(O2CAr(4F-Ph))4(HOMe)8] and [Ni4(μ-OMe)4(O2CAr(Tol))4(HOMe)6], thus suggesting single-molecule magnet behavior. To differentiate the magnetic properties between the symmetric and asymmetric cubanes, detailed electron paramagnetic resonance (EPR) measurements were performed. From the EPR data, taken at various frequencies and temperatures, zero-field splitting parameters D, E, and other higher-order parameters for both cubane samples were extracted. Compared to the symmetric Ni-cubane, the asymmetric one shows an increase in the D and E values by about 20%, thereby suggesting structural engineering effects on the magnetic properties. By using the magnetic parameters determined by EPR, a static magnetization curve at 2 K and a temperature dependence of the magnetic susceptibility were simulated. A good agreement between theoretical and experimental data confirms the validity of the values obtained from EPR measurements.

  18. Effect of bow-type initial imperfection on reliability of minimum-weight, stiffened structural panels

    Science.gov (United States)

    Stroud, W. Jefferson; Krishnamurthy, Thiagaraja; Sykes, Nancy P.; Elishakoff, Isaac

    1993-01-01

    Computations were performed to determine the effect of an overall bow-type imperfection on the reliability of structural panels under combined compression and shear loadings. A panel's reliability is the probability that it will perform the intended function - in this case, carry a given load without buckling or exceeding in-plane strain allowables. For a panel loaded in compression, a small initial bow can cause large bending stresses that reduce both the buckling load and the load at which strain allowables are exceeded; hence, the bow reduces the reliability of the panel. In this report, analytical studies on two stiffened panels quantified that effect. The bow is in the shape of a half-sine wave along the length of the panel. The size e of the bow at panel midlength is taken to be the single random variable. Several probability density distributions for e are examined to determine the sensitivity of the reliability to details of the bow statistics. In addition, the effects of quality control are explored with truncated distributions.

  19. Structural basis for the recognition of complex-type biantennary oligosaccharides by Pterocarpus angolensis lectin.

    Science.gov (United States)

    Buts, Lieven; Garcia-Pino, Abel; Imberty, Anne; Amiot, Nicolas; Boons, Geert-Jan; Beeckmans, Sonia; Versées, Wim; Wyns, Lode; Loris, Remy

    2006-06-01

    The crystal structure of Pterocarpus angolensis lectin is determined in its ligand-free state, in complex with the fucosylated biantennary complex type decasaccharide NA2F, and in complex with a series of smaller oligosaccharide constituents of NA2F. These results together with thermodynamic binding data indicate that the complete oligosaccharide binding site of the lectin consists of five subsites allowing the specific recognition of the pentasaccharide GlcNAc beta(1-2)Man alpha(1-3)[GlcNAc beta(1-2)Man alpha(1-6)]Man. The mannose on the 1-6 arm occupies the monosaccharide binding site while the GlcNAc residue on this arm occupies a subsite that is almost identical to that of concanavalin A (con A). The core mannose and the GlcNAc beta(1-2)Man moiety on the 1-3 arm on the other hand occupy a series of subsites distinct from those of con A.

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

    Science.gov (United States)

    Rimphanitchayakit, Vichien; Tassanakajon, Anchalee

    2010-04-01

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

  1. Spectral emissivity of type E235B low carbon structural steel with different roughnesses

    Science.gov (United States)

    Yu, Kun; Zhang, Feilin; Liu, Dong; Liu, Yufang

    2017-08-01

    A self-built experimental apparatus was employed to study the spectral emissivity of type E235B low carbon structural steel in the wavelength range 2-15 μm at different temperatures by energy comparison method. The surface roughness and topography of the steel E235B were determined by a roughness tester and a scanning electron microscopy, respectively. And then, the spectral emissivity of steel E235B with six different roughnesses was measured before and after oxidation. The measurement results showed that the spectral emissivity increased with the increasing temperature and surface roughness before oxidation. The effect of roughness on the spectral emissivity is different at different wavelength and temperature ranges. However, the oscillatory behavior of the spectral emissivity was observed after oxidation. To explore the possible reasons for emissivity variation, the changes of surface roughness and optical roughness were investigated after oxidation. It is found that both the surface roughness and optical roughness increased after oxidation. Although the optical roughness can be used as one of the parameters to evaluate the effect of surface roughness on the spectral emissivity, it is insufficient to describe the effect of surface morphology on the spectral emissivity.

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

    Science.gov (United States)

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

    2016-05-01

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

  3. [Effect of operational modes on community structure of type I methanotroph in the cover soil of municipal solid waste landfill].

    Science.gov (United States)

    Yu, Ting; He, Pin-Jing; Lü, Fan; Shao, Li-Ming

    2008-10-01

    Type I methanotroph is crucial for methane oxidization and it responses fast to the changes in environment. In this study, 16S rDNA-based denaturing gradient gel electrophoresis (DGGE) gene fingerprint technology was applied to investigate the effect of operational modes, i. e. high-density polyethylene liner (HDPE) isolation or subsurface irrigation of landfill leachate and vegetation, on community structure and diversity of type I methanotroph in soils covering municipal solid waste landfill. 16S rDNA based phylogenetic analysis reveals type I methanotroph in all tested soils belongs to Methylobacter. According to Shannon-Wiener diversity index and principal component analysis, landfill leachate subsurface irrigation and vegetation have more impact on type I methanotroph community structure and diversity than HDPE liner isolation does, and they reduce type I methanotroph diversity. Leachate irrigation is supposed to inhibit the growth of Methylobacter population. Community structure of type I methanotroph in landfill cover soil isolated by HDPE, i.e. invaded by landfill gas, shifts during long-term gas interference. When cover age is 1.5 years old, Shannon-Wiener diversity index of type I methanotroph reaches its maximum.

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

    CERN Document Server

    Ibragimov, Z D

    2001-01-01

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

  5. Crystal structures of type III{sub H} NAD-dependent D-3-phosphoglycerate dehydrogenase from two thermophiles

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S.M. [Department of Studies in Physics, University of Mysore, Mysore 570 006 (India); Pampa, K.J. [Department of Studies in Microbiology, University of Mysore, Mysore 570 006 (India); Manjula, M. [Department of Studies in Physics, University of Mysore, Mysore 570 006 (India); Hemantha Kumar, G. [Department of Studies in Computer Science, University of Mysore, Mysore 570 006 (India); Kunishima, Naoki [Advanced Protein Crystallography Research Group, RIKEN SPring-8 Center, Harima Institute, Hyogo 679-5148 (Japan); Lokanath, N.K., E-mail: lokanath@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Mysore 570 006 (India)

    2014-08-15

    Highlights: • Determined the crystal structures of PGDH from two thermophiles. • Monomer is composed of nucleotide binding domain and substrate binding domain. • Crystal structures of type III{sub H} PGDH. - Abstract: In the L-Serine biosynthesis, D-3-phosphoglycerate dehydrogenase (PGDH) catalyzes the inter-conversion of D-3-phosphoglycerate to phosphohydroxypyruvate. PGDH belongs to 2-hydroxyacid dehydrogenases family. We have determined the crystal structures of PGDH from Sulfolobus tokodaii (StPGDH) and Pyrococcus horikoshii (PhPGDH) using X-ray diffraction to resolution of 1.77 Å and 1.95 Å, respectively. The PGDH protomer from both species exhibits identical structures, consisting of substrate binding domain and nucleotide binding domain. The residues and water molecules interacting with the NAD are identified. The catalytic triad residues Glu-His-Arg are highly conserved. The residues involved in the dimer interface and the structural features responsible for thermostability are evaluated. Overall, structures of PGDHs with two domains and histidine at the active site are categorized as type III{sub H} and such PGDHs structures having this type are reported for the first time.

  6. Two Types of Novel Feedstock Injection Structures of the FCC Riser Reactor

    Institute of Scientific and Technical Information of China (English)

    范怡平; 蔡飞鹏; 时铭显; 徐春明

    2004-01-01

    Based on the analysis of flow characteristics of the FCC riser feedstock injection zone, two novel feedstock injection structures are put forward. By investigating three flow parameters in the feedstock injection zone under the three different structures (the traditional and the novel No. 1, No. 2 structures): the local density, the particle backmixng ratio, and the jet eigen-concentration, the flow feature under three structures were obtained. The experimental results demonstrate that the flow features under both proposed structures are obviously improved comparing with those under the traditional structure. Especially, the performance of the deflector-structured No. 2 is more desirable than that of No. 1.

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

    Directory of Open Access Journals (Sweden)

    David Kim

    2014-01-01

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

  8. Iron-promoted nucleophilic additions to diimine-type ligands: a synthetic and structural study.

    Science.gov (United States)

    Vallina, Ana Tesouro; Stoeckli-Evans, Helen; Neels, Antonia; Ensling, Jürgen; Decurtins, Silvio

    2003-05-19

    We report here three examples of the reactivity of protic nucleophiles with diimine-type ligands in the presence of Fe(II) salts. In the first case, the iron-promoted alcoholysis reaction of one nitrile group of the ligand 2,3-dicyano-5,6-bis(2-pyridyl)-pyrazine (L1) permitted the isolation of an stable E-imido-ester, [Fe(L1')(2)](CF(3)SO(3))(2) (1), which has been characterized by spectroscopic studies (IR, ES-MS, Mössbauer), elemental analysis, and crystallographically. Compound 1 consists of mononuclear octahedrally coordinated Fe(II) complexes where the Fe(II) ion is in its low-spin state. The iron-mediated nucleophilic attack of water to the asymmetric ligand 2,3-bis(2-pyridyl)pyrido[3,4-b]pyrazine (L2) has also been studied. In this context, the crystal structures of two hydration-oxidation Fe(III) products, [Fe(L2')(2)](ClO(4))(3).3CH(3)CN (2) and trans-[FeL2"Cl(2)] (3), are described. Compounds 2 and 3 are both mononuclear Fe(III) complexes where the metals occupy octahedral positions. In principle, L2 is expected to coordinate to metal ions through its bipyridine-type units to form a five-membered ring; however, this is not the case in compounds 2 and 3. In 2, the ligand coordinates through its pyridines and through the hydroxyl group attached to the pyrazine imino carbon after hydration, that is, in an N,O,N tridentate manner. In compound 3, the ligand has suffered further transformations leading to a very stable diamido complex. In this case, the metal ion achieves its octahedral geometry by means of two pyridines, two amido N atoms, and two axial chlorine atoms. Magnetic susceptibility measurements confirmed the spin state of these two Fe(III) species: compounds 2 and 3 are low-spin and high-spin, respectively.

  9. COST-EFFECTIVENESS OF STRUCTURED EDUCATION IN CHILDREN WITH TYPE-1 DIABETES MELLITUS.

    Science.gov (United States)

    Basarir, Hasan; Brennan, Alan; Jacques, Richard; Pollard, Daniel; Stevens, Katherine; Freeman, Jennifer; Wales, Jerry; Price, Katherine

    2016-01-01

    Kids in Control OF Food (KICk-OFF) is a 5-day structured education program for 11- to 16-year-olds with type 1 diabetes mellitus (T1DM) who are using multiple daily insulin injections. This study evaluates the cost-effectiveness of the KICk-OFF education program compared with the usual care using data from the KICk-OFF trial. The short-term within-trial analysis covers the 2-year postintervention period. Data on glycated hemoglobin (HbA1c), severe hypoglycemia, and diabetic ketoacidosis (DKA) were collected over a 2-year follow-up period. Sub-group analyses have been defined on the basis of baseline HbA1c being below 7.5 percent (58.5 mmol/mol) (low group), between 7.5 percent and 9.5 percent (80.3 mmol/mol) (medium group), and over 9.5 percent (high group). The long-term cost-effectiveness evaluation has been conducted by using The Sheffield Type 1 Diabetes Policy Model, which is a patient-level simulation model on T1DM. It includes long-term microvascular (retinopathy, neuropathy, and nephropathy) and macrovascular (myocardial infarction, stroke, revascularization, and angina) diabetes-related complications and acute adverse events (severe hypoglycemia and DKA). The most favorable within-trial scenario for the KICk-OFF arm led to an incremental cost-effectiveness ratio (ICER) of £23,688 (base year 2009) with a cost-effectiveness probability of 41.3 percent. Simulating the long-term complications using the full cohort data, the mean ICER for the base case was £28,813 (base year 2011) and the probability of the KICk-OFF intervention being cost-effective at £20,000/QALY threshold was 42.6 percent, with considerable variation due to treatment effect duration. For the high HbA1c sub-group, the KICk-OFF arm was "dominant" (meaning it provided better health gains at lower costs than usual care) over the usual care arm in each scenario considered. For the whole study population, the cost-effectiveness of KICk-OFF depends on the assumption for treatment effect duration

  10. Crystal structure of Legionella DotD: insights into the relationship between type IVB and type II/III secretion systems.

    Directory of Open Access Journals (Sweden)

    Noboru Nakano

    Full Text Available The Dot/Icm type IVB secretion system (T4BSS is a pivotal determinant of Legionella pneumophila pathogenesis. L. pneumophila translocate more than 100 effector proteins into host cytoplasm using Dot/Icm T4BSS, modulating host cellular functions to establish a replicative niche within host cells. The T4BSS core complex spanning the inner and outer membranes is thought to be made up of at least five proteins: DotC, DotD, DotF, DotG and DotH. DotH is the outer membrane protein; its targeting depends on lipoproteins DotC and DotD. However, the core complex structure and assembly mechanism are still unknown. Here, we report the crystal structure of DotD at 2.0 Å resolution. The structure of DotD is distinct from that of VirB7, the outer membrane lipoprotein of the type IVA secretion system. In contrast, the C-terminal domain of DotD is remarkably similar to the N-terminal subdomain of secretins, the integral outer membrane proteins that form substrate conduits for the type II and the type III secretion systems (T2SS and T3SS. A short β-segment in the otherwise disordered N-terminal region, located on the hydrophobic cleft of the C-terminal domain, is essential for outer membrane targeting of DotH and Dot/Icm T4BSS core complex formation. These findings uncover an intriguing link between T4BSS and T2SS/T3SS.

  11. Exact combined traveling wave solutions and multi-symplectic structure of the variant Boussinesq-Whitham-Broer-Kaup type equations

    Science.gov (United States)

    Yang, Xiao-Feng; Deng, Zi-Chen; Li, Qing-Jun; Wei, Yi

    2016-07-01

    The homogeneous balance of undetermined coefficients method (HBUCM) is firstly proposed to construct not only the exact traveling wave solutions, three-wave solutions, homoclinic solutions, N-soliton solutions, but also multi-symplectic structures of some nonlinear partial differential equations (NLPDEs). By applying the proposed method to the variant Boussinesq equations (VBEs), the exact combined traveling wave solutions and a multi-symplectic structure of the VBEs are obtained directly. Then, the definition and a multi-symplectic structure of the variant Boussinesq-Whitham-Broer-Kaup type equations (VBWBKTEs) which can degenerate to the VBEs, the Whitham-Broer-Kaup equations (WBKEs) and the Broer-Kaup equations (BKEs) are given in the multi-symplectic sense. The HBUCM is also a standard and computable method, which can be generalized to obtain the exact solutions and multi-symplectic structures for some types of NLPDEs.

  12. Spin and valley dependent line-type resonant peaks in electrically and magnetically modulated silicene quantum structures

    Science.gov (United States)

    Zhang, Yuanshan; Guo, Yong

    2017-02-01

    A barrier with a tunable spin-valley dependent energy gap in silicene could be used as a spin and valley filter. Meanwhile, special resonant modes in unique quantum structure can act as energy filters. Hence we investigate valley and spin transport properties in the potential silicene quantum structures, i.e., single ferromagnetic barrier, single electromagnetic barrier and double electric barriers. Our quantum transport calculation indicates that quantum devices of high accuracy and efficiency (100% polarization), based on modulated silicene quantum structures, can be designed for valley, spin and energy filtering. These intriguing features are revealed by the spin, valley dependent line-type resonant peaks. In addition, line-type peaks in different structure depend on spin and valley diversely. The filter we proposed is controllable by electric gating.

  13. Play types, structural history and distribution of Middle Buntsandstein gas fields in NW Germany. Observations and their genetic interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Baerle, C.; Kuehn, M.; Sommer, J. [Wintershall Holding AG, Erdoelwerke Barnstorf (Germany); Clever, B. [Wintershall Noordzee B.V., Rijswijk (Netherlands); Karnin, W.D.; Gast, R.

    2008-10-23

    The Middle Buntsandstein is one of the most important gas reservoirs in the northwestern German area. So far, nearly 100 billion cubic meter gas could be proven in 26 gas fields. The authors of the contribution under consideration report on play type, structural history and distribution of Middle Buntsandstein gas fields in northwestern Germany. The Buntsandstein structures consist of a tectonic-halokinetic structural floor with the three types inversion play, late halogenetic play and early halogenetic play. The development of the Buntsandstein fields depends of the timing of the structural formation and the presence of migration windows. Beside classical migration windows in the Zechstein salina, the internal ranges of the Permian basin require an existence of disturbances which enable a migration of the carbon-generated gases by the second barrier.

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

    Directory of Open Access Journals (Sweden)

    Politanskyi R. L.

    2014-08-01

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

  15. Correlation between arterial vascularity by radiologic study and structural histopathologic type in resected hepatocellular carcinoma(HCC)

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jae Chun; Lee, Jin Wook; Lee, Yong Woo; Jang, Yoo Song; Lee, Sang Jin; Kwon, Hyuk Pyo [College of Medicine, Yeungnam University, Daegu (Korea, Republic of); Cho, Jae Ho [College of Medicine, Sunchunhyang University, Asan (Korea, Republic of)

    1994-12-15

    To analyze the correlation between dynamic vascular pattern and structural histologic type of HCC. The materials consisted of 35 cases of HCC, which could be classified by structural histologic type and had available preoperative arterial dominant images. Excluding one case of pseudo glandular type, we compared structural histologic type of the tumors(trabecular group; 13 cases, mixed group; 10 cases, and non trabecular group; 11 cases) with dynamic vascular pattern such as degrees of tumor staining, severity of tumor vessels on hepatic angiography, and with enhancing degrees of early phase relative to late phase on two-phase incremental bolus dynamic CT. In hepatic angiogram, trabecular group showed stronger tumor staining and more prominent dilatation and irregularity of tumor vessels than those of non trabecular group, and In two-phase incremental bolus dynamic CT, and trabecular group showed more prominent tumor enhancement in early phase than those in late phase. The trabecular type(typical) and non-trabecular type of HCC showed radiologically different vascular patterns and therefore we believe that this maybe the basis with which diagnosis and treatment policy of radiologically atypical HCC could be made.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-01

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

  17. Structural modulation of gut microbiota during alleviation of type 2 diabetes with a Chinese herbal formula.

    Science.gov (United States)

    Xu, Jia; Lian, Fengmei; Zhao, Linhua; Zhao, Yufeng; Chen, Xinyan; Zhang, Xu; Guo, Yun; Zhang, Chenhong; Zhou, Qiang; Xue, Zhengsheng; Pang, Xiaoyan; Zhao, Liping; Tong, Xiaolin

    2015-03-01

    The gut microbiota is hypothesized to have a critical role in metabolic diseases, including type 2 diabetes (T2D). A traditional Chinese herbal formula, Gegen Qinlian Decoction (GQD), can alleviate T2D. To find out whether GQD modulates the composition of the gut microbiota during T2D treatment, 187 T2D patients were randomly allocated to receive high (HD, n=44), moderate (MD, n=52), low dose GQD (LD, n=50) or the placebo (n=41) for 12 weeks in a double-blinded trial. Patients who received the HD or MD demonstrated significant reductions in adjusted mean changes from baseline of fasting blood glucose (FBG) and glycated hemoglobin (HbA1c) compared with the placebo and LD groups. Pyrosequencing of the V3 regions of 16S rRNA genes revealed a dose-dependent deviation of gut microbiota in response to GQD treatment. This deviation occurred before significant improvement of T2D symptoms was observed. Redundancy analysis identified 47 GQD-enriched species level phylotypes, 17 of which were negatively correlated with FBG and 9 with HbA1c. Real-time quantitative PCR confirmed that GQD significantly enriched Faecalibacterium prausnitzii, which was negatively correlated with FBG, HbA1c and 2-h postprandial blood glucose levels and positively correlated with homeostasis model assessment of β-cell function. Therefore, these data indicate that structural changes of gut microbiota are induced by Chinese herbal formula GQD. Specifically, GQD treatment may enrich the amounts of beneficial bacteria, such as Faecalibacterium spp. In conclusion, changes in the gut microbiota are associated with the anti-diabetic effects of GQD.

  18. Layered Double Hydroxides with Hydrotalcite-type Structure Containing Fe3+, Al3+ and Mg2+

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Layered double hydroxides(LDHs) with hydrotalcite-type structure containing Fe3+, Al3+ and Mg2+ were prepared by means of a coprecipitation method. The products were characterized by element analysis, X-ray powder diffraction and transmission electron microscopy. It was found that even if the molar ratio of n(Fe+Al)/n(Fe+Al+Mg)>0.33, yet a pure hydrotalcite-like compound(HTlc) phase was gained when n(Fe)/n(Al+Mg+Fe)≤0.30 and n(Al)/n(Al+Mg+Fe)≤0.30; the Al(OH)3 phase appeared in the products when n(Al)/n(Al+Mg+Fe)>0.30; and an amorphous phase emerged when n(Fe)/n(Al+Mg+Fe)>0.33. These results show that there is no concentration superposition effect between Fe3+ and Al3+ on the crystalline state of the produced samples. In our previous work, the concentration superposition effect between Zn2+ and Mg2+ in the synthesis of Zn-Mg-Al-LDHs was found. For the prepared Fe-Al-Mg-LDHs samples, the value of lattice parameter a is between 0.30-0.32 nm; and the value of lattice parameter c is between 2.30-2.47 nm, the basal spacing is in the range of 0.76-0.83 nm. When the ratio of n(Fe)/n(Al) is a constant, the values of a and c increase with the increase of the Mg2+ content of the produced samples. The mean particle size and the mean crystal grain were determined by virtue of a particle-size instrument, XRD-Scherrer formula and TEM method, respectively.

  19. Thermoelectric material including a multiple transition metal-doped type I clathrate crystal structure

    Science.gov (United States)

    Yang, Jihui; Shi, Xun; Bai, Shengqiang; Zhang, Wenqing; Chen, Lidong; Yang, Jiong

    2012-01-17

    A thermoelectric material includes a multiple transition metal-doped type I clathrate crystal structure having the formula A.sub.8TM.sub.y.sub.1.sup.1TM.sub.y.sub.2.sup.2 . . . TM.sub.y.sub.n.sup.nM.sub.zX.sub.46-y.sub.1.sub.-y.sub.2.sub.- . . . -y.sub.n.sub.-z. In the formula, A is selected from the group consisting of barium, strontium, and europium; X is selected from the group consisting of silicon, germanium, and tin; M is selected from the group consisting of aluminum, gallium, and indium; TM.sup.1, TM.sup.2, and TM.sup.n are independently selected from the group consisting of 3d, 4d, and 5d transition metals; and y.sub.1, y.sub.2, y.sub.n and Z are actual compositions of TM.sup.1, TM.sup.2, TM.sup.n, and M, respectively. The actual compositions are based upon nominal compositions derived from the following equation: z=8q.sub.A-|.DELTA.q.sub.1|y.sub.1-|.DELTA.q.sub.2|y.sub.2- . . . -|.DELTA.q.sub.n|y.sub.n, wherein q.sub.A is a charge state of A, and wherein .DELTA.q.sub.1, .DELTA.q.sub.2, .DELTA.q.sub.n are, respectively, the nominal charge state of the first, second, and n-th TM.

  20. Analysis of local bond-orientational order for liquid gallium at ambient pressure: Two types of cluster structures.

    Science.gov (United States)

    Chen, Lin-Yuan; Tang, Ping-Han; Wu, Ten-Ming

    2016-07-14

    In terms of the local bond-orientational order (LBOO) parameters, a cluster approach to analyze local structures of simple liquids was developed. In this approach, a cluster is defined as a combination of neighboring seeds having at least nb local-orientational bonds and their nearest neighbors, and a cluster ensemble is a collection of clusters with a specified nb and number of seeds ns. This cluster analysis was applied to investigate the microscopic structures of liquid Ga at ambient pressure (AP). The liquid structures studied were generated through ab initio molecular dynamics simulations. By scrutinizing the static structure factors (SSFs) of cluster ensembles with different combinations of nb and ns, we found that liquid Ga at AP contained two types of cluster structures, one characterized by sixfold orientational symmetry and the other showing fourfold orientational symmetry. The SSFs of cluster structures with sixfold orientational symmetry were akin to the SSF of a hard-sphere fluid. On the contrary, the SSFs of cluster structures showing fourfold orientational symmetry behaved similarly as the anomalous SSF of liquid Ga at AP, which is well known for exhibiting a high-q shoulder. The local structures of a highly LBOO cluster whose SSF displayed a high-q shoulder were found to be more similar to the structure of β-Ga than those of other solid phases of Ga. More generally, the cluster structures showing fourfold orientational symmetry have an inclination to resemble more to β-Ga.

  1. Thermal-rheological structure of the lithosphere beneath two types of basins in eastern and western China

    Institute of Scientific and Technical Information of China (English)

    王良书; 李成; 刘福田; 李华; 卢华复; 刘绍文

    2000-01-01

    After calculating thermal-rheological properties of the lithosphere in the Northern Jiangsu basin, the Bohaiwan basin as well as the Jiyang depression in the east and Tarim basin in the west of China, this paper analyzes the relationship between thermal-rheological structures and tectonic evolution of the two types of basins. The results show that the thermal-rheoiogical structures of the lithosphere directly reflect the dynamic processes. Under different dynamic environments, the style of basin formation and the differences in basin evolution are closely related to the dynamic properties of the lithosphere indicated by thermal-rheological structures.

  2. Structured exercise interventions for type 2 diabetes mellitus: Strength of current evidence

    Directory of Open Access Journals (Sweden)

    Mohammed Ejas Hussain

    2011-07-01

    Full Text Available Exercise, along with medical nutrition therapy and pharmacological interventions, is an important component in the clinical management of type 2 diabetes mellitus (T2D. Current clinical guidelines on type 2 diabetes provide no detailed information on the modalities of effective exercise intervention in the treatment of type 2 diabetes. Both endurance and resistance types of exercise seem to be equally effective in improving metabolic control in patients with type 2 diabetes. Determining the best method of providing exercise is clinically relevant to this population. This paper reviews the epidemiology of diabetes and problems of physical function associated with type 2 diabetes and discuss the benefits of exercise therapy on the parameters of glycemic control and function in type 2 diabetes patients, with special reference to Asian Indians. Based on the currently available literature, it is concluded that type 2 diabetes patients should be encouraged to participate in specifically designed exercise intervention programs. Attention should be paid to the avoidance of cardiovascular and musculoskeletal deconditioning. More clinical research is warranted to establish the efficacy of different dosages of exercise intervention in a holistic approach for type 2 diabetes subpopulations within different stages of the disease and various levels of co-morbidity.

  3. The Lenses Structure and Dynamics Survey: luminous and dark matter in high redshift early-type galaxies

    NARCIS (Netherlands)

    Treu, T.; Koopmans, L.

    2003-01-01

    I will present the latest results from the Lenses Structure and Dynamics (LSD) Survey. Using ESI on the Keck Telescope, we have measured spatially resolved stellar kinematics for a sample of 11 early-type galaxies (E/S0s) in the range z=0.1-1, selected as gravitational lenses. By combining lensing a

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    PCR mapping of staphylococcal cassette chromosome mec type IVa and adjacent mobile elements in 94 methicillin-resistant Staphylococcus aureus (MRSA) strains identified two primary structures (A and B) that could be further classified into two (A1 and A2) and five (B1 to B5) variants, primarily...

  5. Structure and properties of α-NaFeO{sub 2}-type ternary sodium iridates

    Energy Technology Data Exchange (ETDEWEB)

    Baroudi, Kristen, E-mail: kbaroudi@princeton.edu [Department of Chemistry, Princeton University, Princeton, NJ 08544 (United States); Yim, Cindi [Department of Chemistry, Princeton University, Princeton, NJ 08544 (United States); Wu, Hui [NIST Center for Neutron Research, Gaithersburg, MD 20899-6102 (United States); Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742-2115 (United States); Huang, Qingzhen [NIST Center for Neutron Research, Gaithersburg, MD 20899-6102 (United States); Roudebush, John H. [Department of Chemistry, Princeton University, Princeton, NJ 08544 (United States); Vavilova, Eugenia [Leibniz Institute for Solid State and Materials Research IFW, Dresden (Germany); Zavoisky Physical Technical Institute, Russian Academy of Sciences, Kazan (Russian Federation); Grafe, Hans-Joachim; Kataev, Vladislav [Leibniz Institute for Solid State and Materials Research IFW, Dresden (Germany); Buechner, Bernd [Leibniz Institute for Solid State and Materials Research IFW, Dresden (Germany); Institut für Festkörperphysik, Technische Universität Dresden, Dresden (Germany); Ji, Huiwen [Department of Chemistry, Princeton University, Princeton, NJ 08544 (United States); Kuo, Changyang; Hu, Zhiwei; Pi, Tun-Wen [Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden (Germany); Pao, Chiwen; Lee, Jyhfu [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan, ROC (China); Mikhailova, Daria; Hao Tjeng, Liu [Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden (Germany); Cava, R.J. [Department of Chemistry, Princeton University, Princeton, NJ 08544 (United States)

    2014-02-15

    The synthesis, structure, and elementary magnetic and electronic properties are reported for layered compounds of the type Na{sub 3−x}MIr{sub 2}O{sub 6} and Na{sub 3−x}M{sub 2}IrO{sub 6}, where M is a transition metal from the 3d series (M=Zn, Cu, Ni, Co, Fe and Mn). The rhombohedral structures, in space group R−3m, were determined by refinement of neutron and synchrotron powder diffraction data. No clear evidence for long range 2:1 or 1:2 honeycomb-like M/Ir ordering was found in the neutron powder diffraction patterns except in the case of M=Zn, and thus in general the compounds are best designated as sodium deficient α-NaFeO{sub 2}-type phases with formulas Na{sub 1−x}M{sub 1/3}Ir{sub 2/3}O{sub 2} or Na{sub 1−x}M{sub 2/3}Ir{sub 1/3}O{sub 2}. Synchrotron powder diffraction patterns indicate that several of the compounds likely have honeycomb in-plane metal–iridium ordering with disordered stacking of the layers. All the compounds are sodium deficient under our synthetic conditions and are black and insulating. Weiss constants derived from magnetic susceptibility measurements indicate that Na{sub 0.62}Mn{sub 0.61}Ir{sub 0.39}O{sub 2}, Na{sub 0.80}Fe{sub 2/3}Ir{sub 1/3}O{sub 2}, Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2}, Na{sub 0.86}Cu{sub 1/3}Ir{sub 2/3}O{sub 2}, and Na{sub 0.89}Zn{sub 1/3}Ir{sub 2/3}O{sub 2} display dominant antiferromagnetic interactions. For Na{sub 0.90}Co{sub 1/3}Ir{sub 2/3}O{sub 2} the dominant magnetic interactions at low temperature are ferromagnetic while at high temperatures they are antiferromagnetic; there is also a change in the effective moment. Low temperature specific heat measurements (to 2 K) on Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2} indicate the presence of a broad magnetic ordering transition. X-ray absorption spectroscopy shows that iridium is at or close to the 4+ oxidation state in all compounds. {sup 23}Na nuclear magnetic resonance measurements comparing Na{sub 2}IrO{sub 3} to Na{sub 0.92}Ni{sub 1/3}Ir

  6. Call types of Bigg's killer whales (Orcinus orca) in western Alaska: Using vocal dialects to assess population structure

    Science.gov (United States)

    Sharpe, Deborah Lynn

    Apex predators are important indicators of ecosystem health, but little is known about the population structure of Bigg's killer whales ( Orcinus orca; i.e. 'transient' ecotype) in western Alaska. Currently, all Bigg's killer whales in western Alaska are ascribed to a single broad stock for management under the US Marine Mammal Protection Act. However, recent nuclear microsatellite and mitochondrial DNA analyses indicate that this stock is likely comprised of genetically distinct sub-populations. In accordance with what is known about killer whale vocal dialects in other locations, I sought to evaluate Bigg's killer whale population structure by examining the spatial distribution of group-specific call types in western Alaska. Digital audio recordings were collected from 33 encounters with Bigg's killer whales throughout the Aleutian and Pribilof Islands in the summers of 2001-2007 and 2009-2010. Recorded calls were perceptually classified into discrete types and then quantitatively described using 12 structural and time-frequency measures. Resulting call categories were objectively validated using a random forest approach. A total of 36 call types and subtypes were identified across the entire study area, and regional patterns of call type usage revealed three distinct dialects, each of which corresponding to proposed genetic delineations. I suggest that at least three acoustically and genetically distinct subpopulations are present in western Alaska, and put forth an initial catalog for this area describing the regional vocal repertoires of Bigg's killer whale call types.

  7. Social influence and adolescent health-related physical activity in structured and unstructured settings: role of channel and type.

    Science.gov (United States)

    Spink, Kevin S; Wilson, Kathleen S; Ulvick, Jocelyn

    2012-08-01

    Social influence channels (e.g., parents) and types (e.g., compliance) have each been related to physical activity independently, but little is known about how these two categories of influence may operate in combination. This study examined the relationships between various combinations of social influence and physical activity among youth across structured and unstructured settings. Adolescents (N=304), classified as high or low active, reported the social influence combinations they received for being active. Participants identified three channels and three types of influence associated with being active. For structured activity, compliance with peers and significant others predicted membership in the high active group (values of psetting, peer compliance (p= .009) and conformity (p= .019) were associated with active group membership. These findings reinforce considering both setting, as well as the channel/type combinations of social influence, when examining health-related physical activity.

  8. Preparation and crystal structure of the Er sub 1 Si sub 2-x (vacancy) sub x compound, derivative of the AlB sub 2 type structure. Preparation et structure cristalline du compose Er sub 1 Si sub 2-x (lacune) sub x , derivee de la structure type AlB sub 2

    Energy Technology Data Exchange (ETDEWEB)

    Ghetta, V.; Houssay, E.; Rouault, A.; Madar, R. (Institut National Polytechnique de Grenoble, 38 - Saint-Martin-d' Heres (FR)); Lambert, B. (Centre National de la Recherche Scientifique, 38 - Grenoble (FR))

    1989-09-01

    The rare earth silicides are of great interest in applications to semiconductor technolgy and form the subject of studies aiming at a better understanding of their physical properties in relation with their structure and composition. A systematic study of the RSi{sub 2-x} compounds, which crystallize in three main structure types ThSi{sub 2}, GdSi{sub 2}, AlB{sub 2} led us to find an orthorhombic superstructure of the hexagonal ErSi{sub 2-x} (AlB{sub 2}-type) structure. This superstructure is caused by a particular arrangement of the vacancies in the silicon sub-lattice.

  9. Structural Elucidation of α-Cyclodextrin-Succinic Acid Pseudo Dodecahydrate: Expanding the Packing Types of α-Cyclodextrin Inclusion Complexes

    Directory of Open Access Journals (Sweden)

    Sofiane Saouane

    2015-12-01

    Full Text Available This paper reports a new packing type of α-cyclodextrin inclusion complexes, obtained here with succinic acid under low-temperature crystallization conditions. The structure of the 1:1 complex is characterized by heavy disorder of the guest, the solvent, and part of the host. The crystal packing belongs to the known channel-type structure; the basic structural unit is composed of cyclodextrin trimers, as opposed to the known isolated molecular or dimeric constructs, packed along the c-axis. Each trimer is made of crystallographically independent molecules assembled in a stacked vase-like cluster. A multi-temperature single-crystal X-ray diffraction analysis reveals the presence of dynamic disorder.

  10. Quantification of age-related changes in the structure model type and trabecular thickness of human tibial cancellous

    DEFF Research Database (Denmark)

    Ding, Ming; Hvid, I

    2000-01-01

    quantification of structure model type, such as plate, rod objects, or mixture of plates or rods. Trabecular thickness is calculated directly from 3-D images, which is especially important for an a priori unknown or changing structure. Furthermore, 2-D trabecular thickness was also calculated based on the plate......Structure model type and trabecular thickness are important characteristics in describing cancellous bone architecture. It has been qualitatively observed that a radical change of trabeculae from plate-like to rod-like occurs in aging, bone remodeling, and osteoporosis. Thickness of trabeculae has......) cancellous bone. In this study, 160 human proximal tibial cancellous bone specimens from 40 normal donors, aged 16 to 85 years, were collected. These specimens were micro-computed tomography (micro-CT) scanned, then the micro-CT images were segmented using optimal thresholds. From accurate 3-D data sets...

  11. Structure of the cytoplasmic domain of Yersinia pestis YscD, an essential component of the type III secretion system

    Energy Technology Data Exchange (ETDEWEB)

    Lountos, George T.; Tropea, Joseph E.; Waugh, David S. (SAIC); (NCI)

    2012-09-17

    The Yersinia pestis YscD protein is an essential component of the type III secretion system. YscD consists of an N-terminal cytoplasmic domain (residues 1-121), a transmembrane linker (122-142) and a large periplasmic domain (143-419). Both the cytoplasmic and the periplasmic domains are required for the assembly of the type III secretion system. Here, the structure of the YscD cytoplasmic domain solved by SAD phasing is presented. Although the three-dimensional structure is similar to those of forkhead-associated (FHA) domains, comparison with the structures of canonical FHA domains revealed that the cytoplasmic domain of YscD lacks the conserved residues that are required for binding phosphothreonine and is therefore unlikely to function as a true FHA domain.

  12. Damage detection in bridge structures under moving loads with phase trajectory change of multi-type vibration measurements

    Science.gov (United States)

    Zhang, Weiwei; Li, Jun; Hao, Hong; Ma, Hongwei

    2017-03-01

    This paper presents a non-model based damage detection approach for bridge structures under moving loads based on the phase trajectory change of multi-type vibration measurements. A brief theoretical background on the vibration of a simply-supported bridge with a crack under moving load is described. The phase trajectories of multi-type dynamic responses are obtained and a damage index is defined as the separated distance between the trajectories of undamaged and damaged structures to indicate the damage location. Numerical studies on a simply-supported beam structure are conducted to investigate the sensitivity and robustness of the proposed approach to accurately identify the damage location. Experimental studies demonstrate that the proposed approach can be used to successfully identify the shear connection failure in a composite bridge model subjected to moving loads.

  13. Morphology, genome sequence, and structural proteome of type phage P335 from Lactococcus lactis

    DEFF Research Database (Denmark)

    Labrie, Simon J.; Josephsen, Jytte; Neve, Horst;

    2008-01-01

    Lactococcus lactis phage P335 is a virulent type phage for the species that bears its name and belongs phage P335 is a virulent type phage for the species that bears its name and belongs to the Siphoviridae family. Morphologically, P335 resembled the L. lactis phages TP901-1 and Tuc2009, except...

  14. Identification and structure of the mating-type locus and development of PCR-based markers for mating type in powdery mildew fungi.

    Science.gov (United States)

    Brewer, Marin Talbot; Cadle-Davidson, Lance; Cortesi, Paolo; Spanu, Pietro D; Milgroom, Michael G

    2011-07-01

    In ascomycetes, mating compatibility is regulated by the mating-type locus, MAT1. The objectives of this study were to identify and sequence genes at the MAT1 locus in the grape powdery mildew fungus, Erysiphe necator, to develop a PCR-based marker for determining mating type in E. necator, and to develop degenerate primers for amplification by PCR of conserved regions of mating-type idiomorphs in other powdery mildew fungi. We identified MAT1-2-1 of the MAT1-2 idiomorph in E. necator based on the homologous sequence in the genome of Blumeria graminis f. sp. hordei and we found MAT1-1-1 and MAT1-1-3 of the MAT1-1 idiomorph from transcriptome sequences of E. necator. We developed and applied a reliable PCR-based multiplex marker to confirm that genotype correlated with mating phenotype, which was determined by pairing with mating-type tester isolates. Additionally, we used the marker to genotype populations of E. necator from different Vitis spp. from throughout the USA. We found both mating types were present in all populations and mating-type ratios did not deviate from 1:1. The mating-type genes in E. necator are similar to those of other Leotiomycetes; however, the structure of the MAT1 locus in E. necator, like the MAT1-2 idiomorph of B. graminis, is markedly different from other ascomycetes in that it is greatly expanded and may contain a large amount of repetitive DNA. As a result, we were unable to amplify and sequence either idiomorph in its entirety. We designed degenerate primers that amplify conserved regions of MAT1-1 and MAT1-2 in E. necator, Podosphaera xanthii, Microsphaera syringae, and B. graminis, representing the major clades of the Erysiphales. These degenerate primers or sequences obtained in this study from these species can be used to identify and sequence MAT1 genes or design mating-type markers in other powdery mildew fungi as well.

  15. A System Identification Software Tool for General MISO ARX-Type of Model Structures

    OpenAIRE

    Lindskog, Peter

    1996-01-01

    The typical system identification procedure requires powerful and versatile software means. In this paper we describe and exemplify the use of a prototype identi#cation software tool, applicable for the rather broad class of multi input single output model structures with regressors that are formed by delayed in- and outputs. Interesting special instances of this model structure category include, e.g., linear ARX and many semi-physical structures, feed-forward neural networks, radial basis fu...

  16. The crystal and magnetic structure relationship in Cu(W{sub 1-x}Mo{sub x})O{sub 4} compounds with wolframite-type structure

    Energy Technology Data Exchange (ETDEWEB)

    Ehrenberg, Helmut [Institute for Materials Science, Darmstadt University of Technology, Darmstadt (Germany)]. E-mail: helmut@tu-darmstadt.de; Theissmann, Ralf; Gassenbauer, Yvonne; Knapp, Michael; Wltschek, Gernot; Weitzel, Hans; Fuess, Hartmut [Institute for Materials Science, Darmstadt University of Technology, Darmstadt (Germany); Herrmannsdoerfer, Thilo; Sheptyakov, Denis [Laboratory for Neutron Scattering, ETH Zuerich and Paul Scherrer Institute, Villigen PSI (Switzerland)

    2002-09-16

    The magnetic structures of Cu(W{sub 1-x}Mo{sub x})O{sub 4} compounds with wolframite-type structure at 1.5 K have been determined by neutron powder diffraction for average composition =0.15, 0.25 and 0.35. For =0.15 the magnetic structure is antiferromagnetic with a magnetic unit cell doubled along the a-axis, k-vector=(1/2, 0, 0), i.e. the same magnetic structure as for CuWO{sub 4}. For =0.25 and 0.35 two magnetic structures are observed: one is identical to that for =0.15, while the other is doubled with respect to the c-axis, k-vector=(0, 0, 1/2), i.e. the same magnetic structure as for the high-pressure modification CuMoO{sub 4} III. The coexistence of these two magnetic arrangements is interpreted as reflecting a slightly inhomogeneous contribution of Mo and W in different crystallites together with a sharp transition between the stability ranges of the two types of magnetic structure with respect to x. The specific Mo:W distributions in the grains of the powdered samples were deduced from a profile analysis based on high-resolution synchrotron powder diffraction data. No additional, intermediate magnetic phase with k-vector=(1/2, 1/2, 0) was found in Cu(W{sub 0.75}Mo{sub 0.25})O{sub 4}, in contrast to predictions in the framework of extended Hueckel calculations based on the precise crystal structure. (author)

  17. The cricothyroid joint--functional aspects with regard to different types of its structure.

    Science.gov (United States)

    Hammer, Georg Philipp; Windisch, Gunther; Prodinger, Peter Michael; Anderhuber, Friedrich; Friedrich, Gerhard

    2010-03-01

    The cricothyroid joint (CTJ) plays a key role in pitch adjustment of the human voice. It allows an external elongation of the vocal fold performed by the cricothyroid muscle with a consecutive stretching and increasing of tension. Phonosurgical methods such as cricothyroid approximation need sophisticated investigations on anatomical and functional principles because of the low satisfaction rates. Fifty cadaveric specimens were analyzed to reveal the morphological and functional anatomy of the CTJ focusing on possible gliding movements in a horizontal and vertical direction. The cartilaginous surfaces of the CTJ were categorized according to Maue and Dickson into three different types (type A: well-defined facet; type B: no definable facet; type C: flat cartilage surface or protuberance) and functional correlations examined. Side different statements and intraindividual differences between male and female specimens were included. Besides from rotational movements, the CTJ allowed horizontal and vertical gliding movements depending on the different types of the cartilaginous surfaces. Especially the difference concerning mobility between type A and the others was highly significant (P<0.001). Two thirds of our specimens showed a similar type in both CTJs, whereas in one third it was asymmetric. In comparison to the possible change of distances between horizontal gliding movements and rotation, rotation caused significant elongation of the vocal folds, which should be proposed in phonosurgical methods for cricothyroid approximation.

  18. The type I error rate for in vivo Comet assay data when the hierarchical structure is disregarded

    DEFF Research Database (Denmark)

    Hansen, Merete Kjær; Kulahci, Murat

    The Comet assay is a sensitive technique for detection of DNA strand breaks. The experimental design of in vivo Comet assay studies are often hierarchically structured, which should be reWected in the statistical analysis. However, the hierarchical structure sometimes seems to be disregarded, and...... the exposition of the statistical methodology and to suitably account for the hierarchical structure of Comet assay data whenever present.......The Comet assay is a sensitive technique for detection of DNA strand breaks. The experimental design of in vivo Comet assay studies are often hierarchically structured, which should be reWected in the statistical analysis. However, the hierarchical structure sometimes seems to be disregarded......, and this imposes considerable impact on the type I error rate. This study aims to demonstrate the implications that result from disregarding the hierarchical structure. DiUerent combinations of the factor levels as they appear in a literature study give type I error rates up to 0.51 and for all combinations...

  19. Structure of the C-type lectin carbohydrate recognition domain of human tetranectin

    DEFF Research Database (Denmark)

    Kastrup, J S; Nielsen, B B; Rasmussen, H

    1998-01-01

    of certain human carcinomas, whereas none or little is present in the corresponding normal tissue. The crystal structure of full-length trimeric TN (2.8 A resolution) has recently been published [Nielsen et al. (1997). FEBS Lett. 412, 388-396]. The crystal structure of the carbohydrate recognition domain...

  20. Bone marrow lambda-type light chain crystalline structures associated with multiple myeloma.

    Science.gov (United States)

    Schvartz, H; Bonhomme, P; Caulet, S; Beorchia, A; Patey, M; Caulet, T

    1985-01-01

    A 58-year-old man showed bone marrow crystalline structures associated with a lambda light chain producing multiple myeloma. Analysis and processing of electron images clearly displayed the periodic structure of the crystals. Immunochemistry suggested that they contained the whole or a fragmented constant portion of immunoglobulin.

  1. Application of high-throughput technologies to a structural proteomics-type analysis of Bacillus anthracis

    NARCIS (Netherlands)

    Au, K.; Folkers, G.E.; Kaptein, R.

    2006-01-01

    A collaborative project between two Structural Proteomics In Europe (SPINE) partner laboratories, York and Oxford, aimed at high-throughput (HTP) structure determination of proteins from Bacillus anthracis, the aetiological agent of anthrax and a biomedically important target, is described. Based up

  2. Evaluating response modification factor (R for some types of steel structure

    Directory of Open Access Journals (Sweden)

    Doralba Valencia Restrepo

    2010-04-01

    Full Text Available Response modification factor (R, tabulated in the Colombian Design Code as NSR-98, is used in this paper for eva-luating internal member forces produced by design earthquake action on steel structures and the inconsistencies pre-sent when designing structures when 1% drift limits must be complied with. The article presents the design of 45 frames corresponding to the seismic resistance system of 5 buildings: 15 special moment frames (SMF, 15 special concentrically-braced frames (CBF and 15 eccentrically-braced frames (EBF. External loads and their combination were used in estimating internal loads and rigidity demands (1% drift were evaluated in line with NSR-98 requi-rements. Member strength requirements were evaluated by using the AISC-2005 seismic provisions for steel structu-red buildings. Modal pushover analysis was used for evaluating the response modification factor for the 45 given frames at different structural performance levels. It was found that this factor was not constant for any of the three structural systems (SMF, CBF and EBF suggested by NSR-98 and that the values of the response modification factor found in the present investigation were smaller than those tabulated in this design code governing everyday structural design. This would lead to significant errors being made in evaluating design forces, not only in the structures but in the support elements (base-plates, foundations, shear walls and any structures attached to buildings constructed in line with the seismic resistance system.

  3. Effects of structural imperfection on gelatinization characteristics of amylopectin starches with A- and B-type crystallinity.

    Science.gov (United States)

    Genkina, Natalia K; Wikman, Jeanette; Bertoft, Eric; Yuryev, Vladimir P

    2007-07-01

    The aim of the present work was to investigate the effect of physical structures on the properties of starch granules. Starches with a high amylopectin content possessing A- and B-type crystallinity were chosen for the study. The gelatinization temperature decreased in the following order: maize (A) > potato (B) > wheat (A) > barley (A), which did not reflect a correlation with the type of crystallinity. Low values of gelatinization temperature were accompanied with high free surface energy of the crystallites. It is proposed that these data are caused by different types of imperfections in starch crystals. Annealing resulted in an enhancement of the gelatinization temperature and a decrease of the free surface energy of the crystallites for all starches reflecting a partial improvement of crystalline perfection. A limited acid hydrolysis (lintnerization) of the starches decreased the gelatinization temperature because of a partial disruption of the crystalline lamellae and an increase of the amount of defects on the edges of the crystallites. Annealing of the lintnerized starches improved the structure of maize and potato starch, giving them similar structural and physicochemical parameters, which was opposite the behavior of the annealed sample from wheat. The possible nature of removable and nonremovable defects inside the crystalline region of the starch granules is discussed. It is concluded that, besides the allomorphic A- and B-types of crystal packing, physical defects in the crystals possess a major impact on starch gelatinization.

  4. Structured primary care for type 2 diabetes has positive effects on clinical outcomes

    NARCIS (Netherlands)

    Fokkens, Andrea S.; Wiegersma, P. Auke; Beltman, Frank W.; Reijneveld, Sijmen A.

    2011-01-01

    Background Patients with type 2 diabetes have an increased risk of developing microvascular and macrovascular complications. In routine diabetes care an adequate reduction of risk factors for these complications is often not achieved.

  5. Sturdy Frame of Type (2,2) Algebras With Application to Semigroup Structure of Semirings

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ We first introduce the concept of frames.Definition 1 We call a type (2,2) algebra (B; +, ) a frame if B is endowed with an upper semilattice order "≤" satisfying the following frame condition: for any a, b ∈ B, a + b ≤ a b and ab ≤ a b, where a b = L.u.b.{a, b}.Similar to the sturdy semilattice of semigroups, we give the following definition of sturdy frame of type (2,2) algebras.

  6. Structure-activity relationships of lanostane-type triterpenoids from Ganoderma lingzhi as α-glucosidase inhibitors.

    Science.gov (United States)

    Fatmawati, Sri; Kondo, Ryuichiro; Shimizu, Kuniyoshi

    2013-11-01

    A series of lanostane-type triterpenoids, identified as ganoderma alcohols and ganoderma acids, were isolated from the fruiting body of Ganoderma lingzhi. Some of these compounds were confirmed as active inhibitors of the in vitro human recombinant aldose reductase. This paper aims to explain the structural requirement for α-glucosidase inhibition. Our structure-activity studies of ganoderma alcohols showed that the OH substituent at C-3 and the double-bond moiety at C-24 and C-25 are necessary to increase α-glucosidase inhibitory activity. The structure-activity relationships of ganoderma acids revealed that the OH substituent at C-11 is an important feature and that the carboxylic group in the side chain is essential for the recognition of α-glucosidase inhibitory activity. Moreover, the double-bond moiety at C-20 and C-22 in the side chain and the OH substituent at C-3 of ganoderma acids improve α-glucosidase inhibitory activity. These results provide an approach with which to consider the structural requirements of lanostane-type triterpenoids from G. lingzhi. An understanding of these requirements is considered necessary in order to improve a new type of α-glucosidase inhibitor.

  7. Optical reflectance and omnidirectional bandgaps in Fibonacci quasicrystals type 1-D multilayer structures containing exponentially graded material

    Science.gov (United States)

    Singh, Bipin K.; Thapa, Khem B.; Pandey, Praveen C.

    2013-06-01

    A theoretical study of optical reflectance and reflection bands of 1-D photonic quasi-crystals (Fibonacci type arrangement) composed of exponentially graded material is presented. The proposed structures consist of two different layers, one of them is of constant refractive index (L) and the other one is of exponentially graded refractive index (S) dielectric materials. Four different generations (2nd, 3rd, 4th and 5th) of the Fibonacci sequence for 10 periods in one dimension (1-D) are considered and compared in view of their optical reflectance and bandgaps for both TE and TM polarisations. Also, we proposed some heterostructures made by the combination of different Fibonacci generations and their periods to obtain suitable omnidirectional reflection band. We used the transfer matrix method (TMM) to obtain the reflectance, bandgaps and omnidirectional reflectional bandgaps (ODR) of such structures in near infrared spectrum (800-2200 nm) at different angles of incidence. We show that ODR exists in these types of structures. The number of ODRs and total bandgap depend on the Fibonacci generations. Extraordinary ODR bandgaps are obtained in the case of heterostructures formed by the combination of different generations of the Fibonacci sequence. The ODR for these structures is similar to the ODR of photonic crystals containing left-handed materials. This work would be useful to study the Fibonacci type photonic crystals having graded index materials and also it will open new window to design several photonic crystal devices like sensors, reflectors, etc. in the infrared region.

  8. The Structure of the Toxin and Type Six Secretion System Substrate Tse2 in Complex with Its Immunity Protein.

    Science.gov (United States)

    Robb, Craig S; Robb, Melissa; Nano, Francis E; Boraston, Alisdair B

    2016-02-01

    Tse2 is a cytoactive toxin secreted by a type six secretion apparatus of Pseudomonas aeruginosa. The Tse2 toxin naturally attacks a target in the cytoplasm of bacterial cells, and can cause toxicity if artificially introduced into eukaryotic cells. The X-ray crystal structure of the complex of Tse2 and its cognate immunity protein Tsi2 revealed a heterotetrameric structure with an extensive binding interface. Structural identity was found between Tse2 and NAD-dependent enzymes, especially ADP-ribosylating toxins, which facilitated the identification of the Tse2 active site and revealed it to be occluded upon binding the inhibitor Tsi2. The structural identity shared with NAD-dependent enzymes, including conserved catalytic residues, suggests that the mechanism of Tse2 toxicity may be NAD dependent.

  9. Structural studies on a non toxic homologue of type II RIPs from bitter gourd: Molecular basis of non toxicity, conformational selection and glycan structure

    Indian Academy of Sciences (India)

    Thyageshwar Chandran; Alok Sharma; M Vijayan

    2015-12-01

    The structures of nine independent crystals of bitter gourd seed lectin (BGSL), a non-toxic homologue of type II RIPS, and its sugar complexes have been determined. The four-chain, two-fold symmetric, protein is made up of two identical two-chain modules, each consisting of a catalytic chain and a lectin chain, connected by a disulphide bridge. The lectin chain is made up of two domains. Each domain carries a carbohydrate binding site in type II RIPS of known structure. BGSL has a sugar binding site only on one domain, thus impairing its interaction at the cell surface. The adenine binding site in the catalytic chain is defective. Thus, defects in sugar binding as well as adenine binding appear to contribute to the non-toxicity of the lectin. The plasticity of the molecule is mainly caused by the presence of two possible well defined conformations of a surface loop in the lectin chain. One of them is chosen in the sugar complexes, in a case of conformational selection, as the chosen conformation facilitates an additional interaction with the sugar, involving an arginyl residue in the loop. The -glycosylation of the lectin involves a plant-specific glycan while that in toxic type H RIPS of known structure involves a glycan which is animal as well as plant specific.

  10. Structure Analysis of Jungle-Gym-Type Gels by Brownian Dynamics Simulation

    Science.gov (United States)

    Ohta, Noriyoshi; Ono, Kohki; Takasu, Masako; Furukawa, Hidemitsu

    2008-02-01

    We investigated the structure and the formation process of two kinds of gels by Brownian dynamics simulation. The effect of flexibility of main chain oligomer was studied. From our results, hard gel with rigid main chain forms more homogeneous network structure than soft gel with flexible main chain. In soft gel, many small loops are formed, and clusters tend to shrink. This heterogeneous network structure may be caused by microgels. In the low density case, soft gel shows more heterogeneity than the high density case.

  11. MWW-type titanosilicate synthesis, structural modification and catalytic applications to green oxidations

    CERN Document Server

    Wu, Peng; Xu, Le; Liu, Yueming; He, Mingyuan

    2013-01-01

    This book provides a comprehensive review of a new generation of selective oxidation titanosilicate catalysts with the MWW topology (Ti-MWW) based on the research achievements of the past 12 years. It gives an overview of the synthesis, structure modification and catalytic properties of Ti-MWW. Ti-MWW can readily be prepared by means of direct hydrothermal synthesis with crystallization-supporting agents, using dual-structure-directing agents and a dry-gel conversion technique. It also can be post-synthesized through unique reversible structure transformation and liquid-phase isomorphous subst

  12. Type V collagen: molecular structure and fibrillar organization of the chicken alpha 1(V) NH2-terminal domain, a putative regulator of corneal fibrillogenesis

    National Research Council Canada - National Science Library

    Linsenmayer, T F; Gibney, E; Igoe, F; Gordon, M K; Fitch, J M; Fessler, L I; Birk, D E

    1993-01-01

    Previous work from our laboratories has demonstrated that: (a) the striated collagen fibrils of the corneal stroma are heterotypic structures composed of type V collagen molecules coassembled along with those of type I collagen, (b...

  13. Influence of Low-Alloy Cast Steel Modification on Primary Structure Refinement, Type and Shape of Non-Metallic Inclusions

    Directory of Open Access Journals (Sweden)

    Bartocha D.

    2015-04-01

    Full Text Available In the article there are presented methods and results of investigation which main aim were determination of influence of melting technology (gas extraction, vacuum refining, slag refining and extraction, deoxidation and degassing and type of used modifiers on the type and shape of non-metallic inclusions and the primary structure refining. Low alloy cast steel melted in laboratory conditions, in an inductive furnace was investigated. Additions of FeNb, FeV, FeTi and FeZr modifiers were applied. The contents of oxygen and nitrogen in obtained cast steel were determined.

  14. La{sub 3}Ir{sub 2} with rhombohedral Er{sub 3}Ni{sub 2}-type structure

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Konrad; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

    2014-10-15

    La{sub 3}Ir{sub 2} is formed upon reaction of the elements at 1273 K in a sealed silica ampoule. The structure was refined from single-crystal X-ray diffractometer data: Er{sub 3}Ni{sub 2}-type structure, R anti 3, a = 895.26(2), c = 1713.01(5) pm, wR = 0.0578, 766 F{sup 2} values, 25 variables. The structure is composed of two simple basic building units: slightly distorted La1 rate at La3{sub 6}La2{sub 2} cubes resembling the tungsten structure and Ir{sub 2} rate at La1{sub 1}La2{sub 2}La3{sub 5} units with an AlB{sub 2}-related coordination (298 pm Ir-Ir in the dumb-bell). Each cube is coordinated by six of the AlB{sub 2} units. The relationship with the U{sub 3}Si{sub 2}-type structure is discussed.

  15. Characteristics of a drift tube cavity with a stabilizing structure of the antipode type

    Energy Technology Data Exchange (ETDEWEB)

    Bomko, V.A.; Khizhnyak, N.A.; Klyucharev, A.P.; Rudyak, B.I.

    1976-07-01

    The passband of a conventional drift tube linac structure has modes which lie uncomfortably close to the fundamental, operating mode. Methods which have been proposed to steepen the dispersion curve in the neighborhood of the operating point include multistem drift tubes, post couplers, crossbar structures, and other techniques. A method is described based on compensation of intermode interaction by suppression of the fields of interfering modes using posts mounted opposite to the drift tube stems.

  16. First-principles molecular spin dynamics study on the magnetic structure of Mn-based alloys with Cu3Au-type crystal structure

    Science.gov (United States)

    Uchida, T.; Kakehashi, Y.; Kimura, N.

    2016-02-01

    The magnetic and electronic structures of Mn3Pt and Mn3Rh, which are three-dimensional frustrated itinerant magnets with a Cu3Au-type crystal structure, have been investigated by means of the first-principles Molecular Spin Dynamics (MSD) method. The theory is based on the first-principles tight-binding linear muffin-tin orbital Hamiltonian combined with the functional integral method and the isothermal MSD technique, and allows us to determine automatically the magnetic structures of itinerant magnets at finite temperatures. The MSD calculations using a self-consistent site-dependent effective medium show that below the Néel temperature Mn3Pt with fixed crystal structure (Cu3Au structure) and volume exhibits a second-order transition from a triangular structure to another noncollinear phase with increasing temperature. Mn3Rh, on the other hand, shows no sign of a phase transition up to the Néel temperature. We found that the Mn-Eg DOS peak, which is responsible for the ferromagnetic couplings among the second nearest-neighbor Mn local moments, develops at the Fermi energy (EF) around 350 K for Mn3Pt, while the peak development for Mn3Rh occurs with increasing temperature slightly above EF.

  17. Crystal structures of wild-type and mutated cyclophilin B that causes hyperelastosis cutis in the American quarter horse.

    Science.gov (United States)

    Boudko, Sergei P; Ishikawa, Yoshihiro; Lerch, Thomas F; Nix, Jay; Chapman, Michael S; Bächinger, Hans Peter

    2012-11-08

    Hyperelastosis cutis is an inherited autosomal recessive connective tissue disorder. Affected horses are characterized by hyperextensible skin, scarring, and severe lesions along the back. The disorder is caused by a mutation in cyclophilin B. The crystal structures of both wild-type and mutated (Gly6->Arg) horse cyclophilin B are presented. The mutation neither affects the overall fold of the enzyme nor impairs the catalytic site structure. Instead, it locally rearranges the flexible N-terminal end of the polypeptide chain and also makes it more rigid. Interactions of the mutated cyclophilin B with a set of endoplasmic reticulum-resident proteins must be affected.

  18. Crystal structures of wild-type and mutated cyclophilin B that causes hyperelastosis cutis in the American quarter horse

    Directory of Open Access Journals (Sweden)

    Boudko Sergei P

    2012-11-01

    Full Text Available Abstract Background Hyperelastosis cutis is an inherited autosomal recessive connective tissue disorder. Affected horses are characterized by hyperextensible skin, scarring, and severe lesions along the back. The disorder is caused by a mutation in cyclophilin B. Results The crystal structures of both wild-type and mutated (Gly6->Arg horse cyclophilin B are presented. The mutation neither affects the overall fold of the enzyme nor impairs the catalytic site structure. Instead, it locally rearranges the flexible N-terminal end of the polypeptide chain and also makes it more rigid. Conclusions Interactions of the mutated cyclophilin B with a set of endoplasmic reticulum-resident proteins must be affected.

  19. Evaluation of the structural steel corrosion behaviour, covered with epoxy-type paints, by means of electrochemical DC techniques

    Science.gov (United States)

    Salas, Y.; Guerrero, L.; Martinez, R.; Chicino, T.; Devia, C.

    2016-02-01

    In this work we have studied the behaviour of the electrochemical corrosion of structural steel AISI SAE 1007 with epoxy coatings, using epoxy-type paints, through techniques such as DC resistance Polarization and Potentio-dynamic tests. In order to determine potential and corrosion rates of these coatings, have been correlated this results with different used electrolytes. For this, coatings were characterized by thickness measurement and continuity measurements. The coatings showed a slight degradation in the testing time, due to defects present in their structure, and the attack by the electrolyte; however, epoxy coating system tends to react with the electrolytes based on their chemical composition.

  20. Discussion on structure type and structure of rebar concrete silo%钢筋混凝土筒仓的结构选型和构造探讨

    Institute of Scientific and Technical Information of China (English)

    刘瑞军

    2014-01-01

    对钢筋混凝土筒仓的仓上建筑、仓顶、仓壁、仓底、仓下支承结构及基础六部分的选型原则及相应的构造要求进行了论述,以期通过合理的设计,提高结构的安全性及经济性,保证工程设计质量达到规范的要求。%This paper discussed the type selection principle and corresponding structure requirements of building above silo,silo top,silo wall, silo bottom,silo below support structure and foundation six parts,in order to through the reasonably design,improved the safety and economic of structure,ensured the engineering design quality reached the standard requirements.

  1. Insertion sequence element single nucleotide polymorphism typing provides insights into the population structure and evolution of Mycobacterium ulcerans across Africa.

    Science.gov (United States)

    Vandelannoote, Koen; Jordaens, Kurt; Bomans, Pieter; Leirs, Herwig; Durnez, Lies; Affolabi, Dissou; Sopoh, Ghislain; Aguiar, Julia; Phanzu, Delphin Mavinga; Kibadi, Kapay; Eyangoh, Sara; Manou, Louis Bayonne; Phillips, Richard Odame; Adjei, Ohene; Ablordey, Anthony; Rigouts, Leen; Portaels, Françoise; Eddyani, Miriam; de Jong, Bouke C

    2014-02-01

    Buruli ulcer is an indolent, slowly progressing necrotizing disease of the skin caused by infection with Mycobacterium ulcerans. In the present study, we applied a redesigned technique to a vast panel of M. ulcerans disease isolates and clinical samples originating from multiple African disease foci in order to (i) gain fundamental insights into the population structure and evolutionary history of the pathogen and (ii) disentangle the phylogeographic relationships within the genetically conserved cluster of African M. ulcerans. Our analyses identified 23 different African insertion sequence element single nucleotide polymorphism (ISE-SNP) types that dominate in different areas where Buruli ulcer is endemic. These ISE-SNP types appear to be the initial stages of clonal diversification from a common, possibly ancestral ISE-SNP type. ISE-SNP types were found unevenly distributed over the greater West African hydrological drainage basins. Our findings suggest that geographical barriers bordering the basins to some extent prevented bacterial gene flow between basins and that this resulted in independent focal transmission clusters associated with the hydrological drainage areas. Different phylogenetic methods yielded two well-supported sister clades within the African ISE-SNP types. The ISE-SNP types from the "pan-African clade" were found to be widespread throughout Africa, while the ISE-SNP types of the "Gabonese/Cameroonian clade" were much rarer and found in a more restricted area, which suggested that the latter clade evolved more recently. Additionally, the Gabonese/Cameroonian clade was found to form a strongly supported monophyletic group with Papua New Guinean ISE-SNP type 8, which is unrelated to other Southeast Asian ISE-SNP types.

  2. Cost-benefit analysis of the construction of different flexible pavement structures considering the axle load and type of binder

    Directory of Open Access Journals (Sweden)

    Lucas Dotto Bueno

    2016-08-01

    Full Text Available The status of Brazilian highways reflects a deficient pavement performance when they are subjected to loadings imposed by heavy traffic. Current legislation, as enacted by Contran (National Traffic Council, has increased the axle weight limit for cargo vehicles by up to 10%. Therefore, the aim of this study was to determine a cost-benefit ratio by using different types of structures, asphalt binders and load intensities. Typical pavements were determined and then analyzed by the software AEMC (SisPav to obtain the horizontal tensile strain (εt values at the bottom of the asphalt concrete layer and, later, the NFATIGUE value. It was found that the increase in weight, within values covered by legislation, might result in a reduction of approximately 50% in the NFATIGUE value for the pavement structures analyzed. As for economic impact, the same weight increase caused a mean increase of 120% in the cost of repeated loading on pavement structures (R$ NFATIGUE-1. It was also observed that structures with more robust asphalt concrete layers can provide the best R$ NFATIGUE-1 ratios. The best results for granular materials were found with thinner layers, associated with a thicker coating. The benefits of modified binders were shown by the analyses of the best structural options: both the polymer-modified binder and the rubber asphalt binder offer significant structural and economic improvements to the structure.

  3. Crystal structure of alluaudite-type NaMg3(HPO42(PO4

    Directory of Open Access Journals (Sweden)

    Ahmed Ould Saleck

    2015-07-01

    Full Text Available The title compound, sodium trimagnesium bis(hydrogen phosphate phosphate, was obtained under hydrothermal conditions. In the crystal, two types of [MgO6] octahedra, one with point group symmetry 2, share edges to build chains extending parallel to [10-1]. These chains are linked together by two kinds of phosphate tetrahedra, HPO4 and PO4, the latter with point group symmetry 2. The three-dimensional framework delimits two different types of channels extending along [001]. One channel hosts the Na+ cations (site symmetry 2 surrounded by eight O atoms, with Na—O bond lengths varying between 2.2974 (13 and 2.922 (2 Å. The OH group of the HPO4 tetrahedron points into the other type of channel and exhibits a strong hydrogen bond to an O atom of the PO4 tetrahedron on the opposite side.

  4. Structural basis of type 2A von Willebrand disease investigated by molecular dynamics simulations and experiments.

    Directory of Open Access Journals (Sweden)

    Gianluca Interlandi

    Full Text Available The hemostatic function of von Willebrand factor is downregulated by the metalloprotease ADAMTS13, which cleaves at a unique site normally buried in the A2 domain. Exposure of the proteolytic site is induced in the wild-type by shear stress as von Willebrand factor circulates in blood. Mutations in the A2 domain, which increase its susceptibility to cleavage, cause type 2A von Willebrand disease. In this study, molecular dynamics simulations suggest that the A2 domain unfolds under tensile force progressively through a series of steps. The simulation results also indicated that three type 2A mutations in the C-terminal half of the A2 domain, L1657I, I1628T and E1638K, destabilize the native state fold of the protein. Furthermore, all three type 2A mutations lowered in silico the tensile force necessary to undock the C-terminal helix α6 from the rest of the A2 domain, the first event in the unfolding pathway. The mutations F1520A, I1651A and A1661G were also predicted by simulations to destabilize the A2 domain and facilitate exposure of the cleavage site. Recombinant A2 domain proteins were expressed and cleavage assays were performed with the wild-type and single-point mutants. All three type 2A and two of the three predicted mutations exhibited increased rate of cleavage by ADAMTS13. These results confirm that destabilization of the helix α6 in the A2 domain facilitates exposure of the cleavage site and increases the rate of cleavage by ADAMTS13.

  5. X-ray inspection of composite materials for aircraft structures using detectors of Medipix type

    Science.gov (United States)

    Jandejsek, I.; Jakubek, J.; Jakubek, M.; Prucha, P.; Krejci, F.; Soukup, P.; Turecek, D.; Vavrik, D.; Zemlicka, J.

    2014-05-01

    This work presents an overview of promising X-ray imaging techniques employed for non-destructive defectoscopy inspections of composite materials intended for the Aircraft industry. The major emphasis is placed on non-tomographic imaging techniques which do not require demanding spatial and time measurement conditions. Imaging methods for defects visualisation, delamination detection and porosity measurement of various composite materials such as carbon fibre reinforced polymers and honeycomb sendwiches are proposed. We make use of the new large area WidePix X-ray imaging camera assembled from up to 100 edgeless Medipix type detectors which is highly suitable for this type of measurements.

  6. A Fibonacci sequence for linear structures with two types of components

    CERN Document Server

    Freixas, Josep; Roura, Salvador

    2009-01-01

    We investigate binary voting systems with two types of voters and a hierarchy among the members in each type, so that members in one class have more influence or importance than members in the other class. The purpose of this paper is to count, up to isomorphism, the number of these voting systems for an arbitrary number of voters. We obtain a closed formula for the number of these systems, this formula follows a Fibonacci sequence with a smooth polynomial variation on the number of voters.

  7. Crash-Induced Vibration and Safety Assessment of Breakaway-Type Post Structures Made of High Anticorrosion Steels

    Directory of Open Access Journals (Sweden)

    Sang-Youl Lee

    2016-01-01

    Full Text Available This study deals with car crash effects and passenger safety assessment of post structures with breakaway types using high performance steel materials. To disperse the impact force when a car crashes into a post, the post could be designed with a breakaway feature. In this study, we used a new high anticorrosion steel for the development of advanced breakaways. Based on the improved Cowper-Symonds model, specific physical properties to the high anticorrosion steel were determined. In particular, the complex mechanism of breakaways was studied using various parameters. The parametric studies are focused on the various effects of car crash on the structural performance and passenger safety of breakaway-type posts. The combined effects of using different steel materials on the dynamic behavers are also investigated.

  8. New type of chimera structures in a ring of bistable FitzHugh–Nagumo oscillators with nonlocal interaction

    Energy Technology Data Exchange (ETDEWEB)

    Shepelev, I.A., E-mail: igor_sar@li.ru; Vadivasova, T.E., E-mail: vadivasovate@yandex.ru; Bukh, A.V., E-mail: buh.andrey@yandex.ru; Strelkova, G.I., E-mail: strelkovagi@info.sgu.ru; Anishchenko, V.S., E-mail: wadim@info.sgu.ru

    2017-04-25

    We study the spatiotemporal dynamics of a ring of nonlocally coupled FitzHugh–Nagumo oscillators in the bistable regime. A new type of chimera patterns has been found in the noise-free network and when isolated elements do not oscillate. The region of existence of these structures has been explored when the coupling range and the coupling strength between the network elements are varied. - Highlights: • Dynamics of a ring of nonlocally coupled FitzHugh–Nagumo oscillators in the bistable regime is studied. • A new type of chimera patterns has been found in the noise-free network. • The region of existence of new structures has been explored when varying the coupling parameters.

  9. Structure design and motion simulation of the pin-cycloid gear planetary reducer with ring-plate-type

    Science.gov (United States)

    Duan, Hongjie; Li, Lijun; Tao, Junyi

    2017-06-01

    The pin-cycloid gear planetary reducer with ring-plate-type is a new type of reducers. It has high transmission ratio range and high efficiency. In this paper the working principle of pin-cycloid gear planetary reducer is discussed, and the structure of the reducer is designed. Especially for the complexity and the difficulty in modelling of the cycloid gear tooth profile, the parametric design module of cycloid gear is developed to solve the cycloid gear modelling problem through the second development of Solid Works. At last, the speed schemes of the input shaft and output shaft of the reducer are obtained by the motion simulation. Through the analysis of the simulation curves, the rationality of the structure design is proved, which provides a theoretical basis for the design and manufacture of the reducer.

  10. Spin-glass transition in Ni carbide single crystal nanoparticles with Ni3C − type structure

    Directory of Open Access Journals (Sweden)

    S. Fujieda

    2016-05-01

    Full Text Available Hexagonal shaped nanoparticles about 60 nm in size were successfully synthesized in tetraethylene glycol solution containing polyvinylpyrrolidone. By the analysis of the electron diffraction pattern, these were identified as a single crystal of Ni carbide with Ni3C − type structure. Their magnetization curve at 5 K was not completely saturated under a magnetic field of 5 T. The thermomagnetization curves after zero-field cooling and after field cooling exhibited the magnetic cooling effect at low temperatures. Furthermore, the 2nd order nonlinear term of AC magnetic susceptibility exhibited a negative divergence at about 17 K. It is concluded that Ni carbide single crystal nanoparticles with the Ni3C − type structure exhibit spin-glass transition at low temperatures.

  11. A non-normal Fefferman-type construction of split-signature conformal structures admitting twistor spinors

    CERN Document Server

    Hammerl, Matthias

    2011-01-01

    We treat a non-normal Fefferman-type construction based on an inclusion $\\SL(n+1)\\embed\\Spin(n+1,n+1)$. The construction associates a split signature $(n,n)$-conformal spin structure to a projective structure of dimension $n$. For $n\\geq 3$ the induced conformal Cartan connection is shown to be normal if and only if it is flat. The main technical work of this article consists in showing that in the non-flat case the normalised conformal Cartan connection still allows a parallel (pure) spin-tractor and thus a corresponding (pure) twistor spinor on the conformal space. The Fefferman-type construction presented here is an alternative approach to study a construction of Dunajski-Tod

  12. Application of the new LDA+GTB method for the band structure calculation of n-type cuprates

    Energy Technology Data Exchange (ETDEWEB)

    Korshunov, M.M. [L.V. Kirensky Institute of Physics, Siberian Branch of Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation)]. E-mail: mkor@iph.krasn.ru; Ovchinnikov, S.G. [L.V. Kirensky Institute of Physics, Siberian Branch of Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Gavrichkov, V.A. [L.V. Kirensky Institute of Physics, Siberian Branch of Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Nekrasov, I.A. [Institute of Metal Physics, Russian Academy of Sciences-Ural Division, 620219 Yekaterinburg GSP-170 (Russian Federation); Pchelkina, Z.V. [Institute of Metal Physics, Russian Academy of Sciences-Ural Division, 620219 Yekaterinburg GSP-170 (Russian Federation); Anisimov, V.I. [Institute of Metal Physics, Russian Academy of Sciences-Ural Division, 620219 Yekaterinburg GSP-170 (Russian Federation)

    2006-05-01

    A novel hybrid scheme is proposed and applied for band structure calculations of undoped n-type cuprate Nd{sub 2}CuO{sub 4}. The ab initio LDA calculation is used to obtain single electron and Coulomb parameters of the multiband Hubbard-type model. In strong correlation regime the electronic structure within this model is calculated by the generalized tight-binding (GTB) method, that combines the exact diagonalization of the model Hamiltonian for a small cluster with perturbation treatment of the intercluster hopping and interactions. For Nd{sub 2}CuO{sub 4}, this scheme results in charge transfer insulator with value of the gap and band dispersion in agreement to the experimental data.

  13. Redetermination of Nd2Ti2O7: a non-centrosymmetric structure with perovskite-type slabs.

    Science.gov (United States)

    Ishizawa, Nobuo; Ninomiya, Keisuke; Sakakura, Terutoshi; Wang, Jun

    2013-04-01

    Single crystals of dineodymium(III) dititanium(IV) hepta-oxide, Nd2Ti2O7, were synthesized by the flux method and found to belong to the family of compounds with perovskite-type structural motifs. The asymmetric unit contains four Nd, four Ti and 14 O-atom sites. The perovskite-type slabs are stacked parallel to (010) with a thickness corresponding to four corner-sharing TiO6 octa-hedra. The Nd and Ti ions are displaced from the geometrical centres of respective coordin-ation polyhedra so that the net polarization occurs along the c axis. The investigated crystals were all twinned and have a halved monoclinic unit cell in comparison with the first structure determination of this compound [Scheunemann & Müller-Buschbaum (1975 ▶). J. Inorg. Nucl. Chem. 37, 2261-2263].

  14. Atom type preferences, structural diversity, and property profiles of known drugs, leads, and nondrugs: a comparative assessment.

    Science.gov (United States)

    Viswanadhan, Vellarkad N; Rajesh, Hariharan; Balaji, Vitukudi N

    2011-05-09

    A new characterization of known drug, lead, and representative nondrug databases was performed taking into account several properties at the atomic and molecular levels. This characterization included atom type preferences, intrinsic structural diversity (Atom Type Diversity, ATD), and other well-known physicochemical properties, as an approach for rapid assessment of druglikeness for small molecule libraries. To characterize ATD, an elaborate united atom classification, UALOGP (United Atom Log P), with 148 atom types, was developed along with associated atomic physicochemical parameters. This classification also enabled an analysis of atom type and physicochemical property distributions (for calculated log P, molar refractivity, molecular weight, total atom count, and ATD) of drug, lead, and nondrug databases, a reassessment of the Ro5 (Rule of Five) and GVW (Ghose−Viswanadhan−Wendoloski) criteria, and development of new criteria and ranges more accurately reflecting the chemical space occupied by small molecule drugs. A relative druglikeness parameter was defined for atom types in drugs, identifying the most preferred types. The present work demonstrates that drug molecules are constitutionally more diverse relative to nondrugs, while being less diverse than leads.

  15. Structure-spectroscopic relationship of co-crystals between a rare chromone structure type of barakol and some organic acids

    Science.gov (United States)

    Chimsook, T.; Teerawatananond, T.; Ngamrojnavanich, N.; Chaichit, N.; Kongsaeree, P.; Muangsin, N.

    2013-12-01

    Barakol, extracted from Cassia siamea Lamk. having an anxiolytic property, consists of a rare chromone core structure, therefore, in this work we investigate relation between the X-ray crystallography and physical properties such as spectroscopic data and the intermolecular interactions of the keto-enol forms based on the CSD search, especially e.g. hydrogen bonding, π-π interactions, ionic interactions and acid-base interactions and clarifies their ambiguous spectroscopic properties. The 1:1 molecular complexes of barakol and carboxylic acid (phthalic acid and 3-hydroxybenzoic acid) were prepared and the X-ray crystallographic studies revealed that the barakol-phthalate complex exists in an ion-pair complex. The formation of barakol-phthalate ion-pair complex is stabilized by the complementary of ion-ion interactions, π-π interactions and hydrogen bonding. The barakol-3-hydroxybenzoic acid complex is a π-π molecular complex. The co-crystallization of barakol-3-hydroxybenzoic acid complex is solely stabilized by π-π interactions. The spectroscopic studies including IR, 1H NMR and 13C NMR are consistent with the results from the X-ray analysis. The 1H NMR spectrum of the barakol and phthalic acid complex in a mixture of CDCl3-CD3OD showed a dramatic spectral changes with downfield shifts of the ortho-protons of phthalic acid (ΔδH(ppm) = 0.37), and the proton resonances of barakol (ΔδH(ppm) = 0.31 for proton H3, 0.53 for proton H4, 0.57 for proton H6 and 0.33 for proton H9).

  16. New type of chimera structures in a ring of bistable FitzHugh-Nagumo oscillators with nonlocal interaction

    Science.gov (United States)

    Shepelev, I. A.; Vadivasova, T. E.; Bukh, A. V.; Strelkova, G. I.; Anishchenko, V. S.

    2017-04-01

    We study the spatiotemporal dynamics of a ring of nonlocally coupled FitzHugh-Nagumo oscillators in the bistable regime. A new type of chimera patterns has been found in the noise-free network and when isolated elements do not oscillate. The region of existence of these structures has been explored when the coupling range and the coupling strength between the network elements are varied.

  17. The Dynamics of an Impulsive Predator-Prey System with Stage Structure and Holling Type III Functional Response

    Directory of Open Access Journals (Sweden)

    Zhixiang Ju

    2015-01-01

    Full Text Available Based on the biological resource management of natural resources, a stage-structured predator-prey model with Holling type III functional response, birth pulse, and impulsive harvesting at different moments is proposed in this paper. By applying comparison theorem and some analysis techniques, the global attractivity of predator-extinction periodic solution and the permanence of this system are studied. At last, examples and numerical simulations are given to verify the validity of the main results.

  18. Van der Waals Type Model and Structure in bar{p}p Elastic Scattering at High Energies

    Science.gov (United States)

    Aleem, F.

    1983-10-01

    The most recent measurements of the angular distribution for bar{p}p elastic scattering at pL=50, 100 and 200 GeV/ c which show a structure near -t=1.4 (GeV/ c)2, with squared four momentum transter -t extended to 5(GeV/ c)2, and the total cross section data for 50 <= pL <= 280GeV/ c have been simultaneously fitted by using the Van der Waals type model.

  19. Structural studies of the O-specific polysaccharide(s) from the lipopolysaccharide of Azospirillum brasilense type strain Sp7.

    Science.gov (United States)

    Sigida, Elena N; Fedonenko, Yuliya P; Shashkov, Alexander S; Zdorovenko, Evelina L; Konnova, Svetlana A; Ignatov, Vladimir V; Knirel, Yuriy A

    2013-10-18

    Lipopolysaccharide was obtained by phenol-water extraction from dried bacterial cells of Azospirillum brasilense type strain Sp7. Mild acid hydrolysis of the lipopolysaccharide followed by GPC on Sephadex G-50 resulted in a polysaccharide mixture, which was studied by composition and methylation analyses, Smith degradation and (1)H and (13)C NMR spectroscopy. The following polysaccharide structures were established, where italics indicate a non-stoichiometric (∼40%) 2-O-methylation of l-rhamnose.

  20. Structural consistency analysis of recombinant and wild-type human serum albumin

    Science.gov (United States)

    Cao, Hui-Ling; Sun, Li-Hua; Liu, Li; Li, Jian; Tang, Lin; Guo, Yun-Zhu; Mei, Qi-Bing; He, Jian-Hua; Yin, Da-Chuan

    2017-01-01

    Recombinant human serum albumin (rHSA) is potential alternatives for human serum albumin (HSA) which may ease severe shortage of HSA worldwide. In theory, rHSA and HSA are the same. Structure decides function. Therefore, the 3D structural consistency analysis of rHSA and HSA is outmost importance, which is the base of their function consistency. In this paper, the crystal structures of rHSA at resolution limit of 2.22 Å and HSA at 2.30 Å were determined by X-ray diffraction (XRD), which were deposited in the Protein Data Bank (PDB) with accession codes 4G03 (rHSA) and 4G04 (HSA). The differences between rHSA and HSA were systematically analyzed from the crystallization behavior, diffraction data and three-dimensional (3D) structure. The superimposed contrasted analysis indicated that rHSA and HSA achieved a structural similarity of 99% with an r.m.s. deviation of 0.397 Å for the corresponding overall Cα atoms. In addition, the number of α-helices in the rHSA or HSA molecule was verified to be 30. As a result, rHSA can potentially replace HSA. The study provides a theoretical and experimental basis for the clinical and additional applications of rHSA. Meanwhile, it is also a good example for applications of genetic engineering.

  1. Psychological Type, Decision-Making Style, and Reactions to Structured Career Interventions.

    Science.gov (United States)

    Tinsley, Howard E. A.; Tinsley, Diane J.; Rushing, James

    2002-01-01

    An intervention for 50 career-undecided women helped them identify decision-making barriers, consider vocational interests, and formulate provisional major and career choices. Women who were introverted and whose decision-making style was rational reported greater benefits from the intervention than those whose personality type was perceiving and…

  2. Structural Evolution of Early-type Galaxies to z=2.5 in CANDELS

    CERN Document Server

    Chang, Yu-Yen; Rix, Hans-Walter; Holden, Bradford; Bell, Eric F; McGrath, Elizabeth J; Wuyts, Stijn; Häußler, Boris; Barden, Marco; Faber, S M; Mozena, Mark; Ferguson, Henry C; Guo, Yicheng; Galametz, Audrey; Grogin, Norman A; Kocevski, Dale D; Koekemoer, Anton M; Dekel, Avishai; Huang, Kuang-Han; Hathi, Nimish P; Donley, Jennifer

    2013-01-01

    Projected axis ratio measurements of 880 early-type galaxies at redshifts 11 early-type galaxies show a variety of intrinsic shapes; even at a fixed mass, the projected axis ratio distributions cannot be explained by random projection of a set of galaxies with very similar intrinsic shapes. However, a two-population model for the intrinsic shapes, consisting of a triaxial, fairly round population, combined with a flat (c/a~0.3) oblate population, adequately describes the projected axis ratio distributions of both present-day and z>1 early-type galaxies. We find that the proportion of oblate vs. triaxial galaxies depends both on the galaxies stellar mass, and - at a given mass - on redshift. For present-day and z1 this trend is much weaker over the mass range explored here (10^101, compared to 0.20+-0.02 at z~0.1. In contrast, the oblate fraction among low-mass early-type galaxies (log(M*/M_sun)1 to 0.72+-0.06 at z=0. [Abridged

  3. Structure of Spa15, a type III secretion chaperone from Shigella flexneri with broad specificity

    NARCIS (Netherlands)

    Eerde, André van; Hamiaux, Cyril; Pérez, Javier; Parsot, Claude; Dijkstra, Bauke W.

    2004-01-01

    Type III secretion (TTS) systems are used by many Gram-negative pathogens to inject virulence proteins into the cells of their hosts. Several of these virulence effectors require TTS chaperones that maintain them in a secretion-competent state. Whereas most chaperones bind only one effector, Spa15 f

  4. Structural and mechanistic insights into ABC-type ECF transporters for vitamin uptake

    NARCIS (Netherlands)

    Dosz-Majsnerowska, Maria

    2014-01-01

    Dit proefschrift gaat over de relatie tussen de structuur en het mechanisme van ABC-type ECF transporters voor vitamines, uit de bacterie Lactococcus lactis. Energy-Coupling Factor (ECF) transporters vormen een subgroep van de ATP-binding cassette (ABC) transporters en zijn betrokken bij de opname v

  5. Phase structure, critical points and susceptibilities in Nambu-Jona-Lasinio type models

    CERN Document Server

    De Sousa, C A; Ruivo, M C

    2008-01-01

    We investigate the chiral phase transition at finite temperature and chemical potential within SU(2) and SU(3) Nambu-Jona-Lasinio type models. The behavior of the baryon number susceptibility and the specific heat, in the vicinity of the critical end point, is studied. The class of the critical points is analyzed by calculating critical exponents.

  6. Contrast structures for a quasilinear Sobolev-type equation with unbalanced nonlinearity

    Science.gov (United States)

    Bykov, A. A.; Nefedov, N. N.; Sharlo, A. S.

    2014-08-01

    The existence of a solution to a generalized Kolmogorov-Petrovskii-Piskunov equation is proved and its asymptotic expansion of the internal transition layer type is constructed. The convergence of the asymptotics is proved by applying the asymptotic comparison principle developed for a new class of problems.

  7. Type 2 diabetes in primary care in belgium: need for structured shared care.

    NARCIS (Netherlands)

    Goderis, G.; Borgermans, L.D.A.; Heyrman, J.; Broeke, C.V.; Grol, R.P.T.M.; Boland, B.; Mathieu, C.

    2009-01-01

    OBJECTIVE: To picture the profile of type 2 diabetic patients in Belgium and to study the quality of care in the primary care setting, with regard, to multi-factorial approach of the disease. METHODS: Observational study of all known DM2-patients registered by 120 volunteer general practitioners. Qu

  8. Structure of Spa15, a type III secretion chaperone from Shigella flexneri with broad specificity

    NARCIS (Netherlands)

    Eerde, André van; Hamiaux, Cyril; Pérez, Javier; Parsot, Claude; Dijkstra, Bauke W.

    2004-01-01

    Type III secretion (TTS) systems are used by many Gram-negative pathogens to inject virulence proteins into the cells of their hosts. Several of these virulence effectors require TTS chaperones that maintain them in a secretion-competent state. Whereas most chaperones bind only one effector, Spa15

  9. Structural and mechanistic insights into ABC-type ECF transporters for vitamin uptake

    NARCIS (Netherlands)

    Dosz-Majsnerowska, Maria

    2014-01-01

    Dit proefschrift gaat over de relatie tussen de structuur en het mechanisme van ABC-type ECF transporters voor vitamines, uit de bacterie Lactococcus lactis. Energy-Coupling Factor (ECF) transporters vormen een subgroep van de ATP-binding cassette (ABC) transporters en zijn betrokken bij de opname

  10. Examining Culturally Structured Learning Environments with Different Types of Music-Linked Movement Opportunity

    Science.gov (United States)

    Cole, Juanita M.; Boykin, A. Wade

    2008-01-01

    This study describes two experiments that extended earlier work on the Afrocultural theme Movement Expression. The impact of various learning conditions characterized by different types of music-linked movement on story recall performance was examined. African American children were randomly assigned to a learning condition, presented a story, and…

  11. Changes in the structural and biochemical composition of the arterial wall in type 2 diabetes patients

    DEFF Research Database (Denmark)

    Rørdam Preil, Simone

    Arteriel stivhed er et normalt aldersbetinget fænomen. Hos patienter med type 2 diabetes synes udviklingen af arteriel stivhed accelereret, hvilket kunne være årsagen til den forøgede incidens af kardiovaskulære sygdomme hos disse patienter. Ophobningen af kollagen og/eller nedbrydningen af elastin...... ikke-atherosclerotisk arterievæv fra patienter med og uden type 2 diabetes. Arteriesnittene fra mammaria arterierne blev farvet for makrofager, elastin, kollagen og α smooth muscle actin, hvorefter vi målte området for kollagen og elastin og antallet af celler, der farves for α smooth muscle actin, ved...... laget signifikant lavere hos patienter med diabetes, og kollagen farvningen viste et større farvet område i intima og media lagene hos type 2 diabetes patienter end for patienterne uden diabetes. Ydermere forholder det sig således, at størstedelen af patienter med type 2 diabetes bliver behandlet med...

  12. Spectroscopic Evidence for an Oxazolone Structure in Anionic b-Type Peptide Fragments

    NARCIS (Netherlands)

    Grzetic, J.; Oomens, J.

    2012-01-01

    Infrared spectra of anionic b-type fragments generated by collision induced dissociation (CID) from deprotonated peptides are reported. Spectra of the b(2) fragments of deprotonated AlaAlaAla and AlaTyrAla have been recorded over the 800-1800 cm(-1) spectral range by multiple-photon dissociation (MP

  13. Spectroscopic evidence for an oxazolone structure in anionic b-type peptide fragments

    NARCIS (Netherlands)

    J. Grzetic; J. Oomens

    2012-01-01

    Infrared spectra of anionic b-type fragments generated by collision induced dissociation (CID) from deprotonated peptides are reported. Spectra of the b2 fragments of deprotonated AlaAlaAla and AlaTyrAla have been recorded over the 800-1800 cm-1 spectral range by multiple-photon dissociation (MPD) s

  14. Structural analysis of plate-type fuel assemblies and development of a non-destructive method to assess their integrity

    Energy Technology Data Exchange (ETDEWEB)

    Caresta, Mauro, E-mail: mcaresta@yahoo.it [School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney 2052, NSW (Australia); Wassink, David [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights 2234, NSW (Australia)

    2013-09-15

    Highlights: • A plate-type fuel assembly is made of thin plates mounted in a box-like structure. • Drag force from the coolant can shift the plates. • A non invasive method is proposed to test the strength of the plate connections. • The natural frequencies’ shift is used to assess the fuel integrity. -- Abstract: This work is concerned with the structural behaviour and the integrity of parallel plate-type nuclear fuel assemblies. A plate-type assembly consists of several thin plates mounted in a box-like structure and is subjected to a coolant flow that can result in a considerable drag force. A finite element model of an assembly is presented to study the sensitivity of the natural frequencies to the stiffness of the plates’ junctions. It is shown that the shift in the natural frequencies of the torsional modes can be used to check the global integrity of the fuel assembly while the local natural frequencies of the inner plates can be used to estimate the maximum drag force they can resist. Finally a non-destructive method is developed to assess the resistance of the inner plates to bear an applied load. Extensive computational and experimental results are presented to prove the applicability of the method presented.

  15. [Pervasive developmental disorder in adults; importance of diagnosis in concern to the type of ego structure with PDD].

    Science.gov (United States)

    Hirosawa, Masataka

    2011-01-01

    Most adult patients with pervasive developmental disorder (PDD) who consult with psychiatrists for the first time may have normal intelligence. In diagnosing high-functioning PDD to adult patients, we should pay much attention to psychological consistency which exists between developmental problems in childhood, developed personality, recent problems in social adjustment, and manifested psychiatric symptoms. In order to understand these relationships, considering the patients' type of ego structure ("PDD ego type") seems to be useful. "PDD ego type" is characterized by their unique self-universe image which takes form of grid one (just like a touch panel), which is decisively different from the form of a radial or concentric circle held by most people (Jung, C.G). This self-universe image characterizes adult PDD patients' psychiatric symptoms, unsuitable social performance, and their "personality."

  16. Review of English Language Library and Information Science Weblogs: Analyzing the Link between Weblog Types and Their Technical /Content Structure

    Directory of Open Access Journals (Sweden)

    Tahereh Karami

    2010-09-01

    Full Text Available Weblog has become well established as one of the Web 2.0 products. Given the essential nature of their job, librarians and information professionals, can use weblog as a quick and easy mean for information and knowledge sharing. The present study reviews some 150 LIS weblogs in order to examine and analyze the link between weblog types (personal, library-owned or group operated with their content and technical structure. Webometric methods were deployed for selection of the sample. The findings indicated that there is a significant correlation between the weblog types and their update frequency. The same holds between the weblog types and their content. But no such significance was observed with respect to the weblog publishing tools. The investigators believe that the links uncovered could also hold true for Iranian LIS weblogs.

  17. Structure of Glycerol Dehydratase Reactivase: A New Type of Molecular Chaperone

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Der-Ing; Reiss, Lisa; Turner, Jr., Ivan; Dotson, Garry (Dupont)

    2010-03-08

    The function of glycerol dehydratase (GDH) reactivase is to remove damaged coenzyme B{sub 12} from GDH that has suffered mechanism-based inactivation. The structure of GDH reactivase from Klebsiella pneumoniae was determined at 2.4 {angstrom} resolution by the single isomorphous replacement with anomalous signal (SIR/AS) method. Each tetramer contains two elongated 63 kDa {alpha} subunits and two globular 14 kDa {beta} subunits. The {alpha} subunit contains structural features resembling both GroEL and Hsp70 groups of chaperones, and it appears chaperone like in its interactions with ATP. The fold of the {beta} subunit resembles that of the {beta} subunit of glycerol dehydratase, except that it lacks some coenzyme B12 binding elements. A hypothesis for the reactivation mechanism of reactivase is proposed based on these structural features.

  18. Design of an Improved Type Rotary Inductive Coupling Structure for Rotatable Contactless Power Transfer System

    Directory of Open Access Journals (Sweden)

    Lee Jia-You

    2015-01-01

    Full Text Available This paper is aimed at analyzing the rotary inductive coupling structure of contactless rotary transformer. The main feature of the proposed rotatable contactless power transfer system is which winding is coaxial-interlayered for improving the magnetic coupling capability. There is no ferrite core used in the secondary-side of the rotary inductive coupling structure, this helps to ease the exerted force that is stress by the secondary-side on spindle. In order to verify the feasibility of the proposed contactless power transfer system for rotary applications, an inductive powered rotary machinery and the control system have been integrated. The experimental results show that the maximum power transfer efficiency of the proposed rotary inductive coupling structure is about 94.8%. The maximum output power received in the load end is 1030 W with transmission efficiency of 88%.

  19. Elucidation of the structure of the oligosaccharide from wild type Moraxella bovis Epp63 lipooligosaccharide.

    Science.gov (United States)

    De Castro, Cristina; Grice, I Darren; Daal, Terese-Marie; Peak, Ian R; Molinaro, Antonio; Wilson, Jennifer C

    2014-03-31

    Moraxella bovis is a Gram-negative microorganism that causes Infectious Bovine Keratoconjunctivitis (IBK), colloquially known as 'Pink eye' in cattle worldwide. Lipopolysaccharides/lipooligosaccharides are the predominant glycans on the surface of Gram-negative microorganisms. Structural elucidation of the oligosaccharide structure of the rough phenotype of Moraxella bovis strain Epp63 was determined using GC-MS, methylation analysis, and NMR spectroscopy. The oligosaccharide is a branched structure that comprises 10 sugars in addition to KDO. The unusual features of this oligosaccharide include the fact that the oligosaccharide is devoid of heptose. The KDO residue is directly attached to a (→4,6)-branched glucose and additionally contains a terminal open chain acetal-linked N-acetylgalactosamine, (1S)-GalaNAc residue →4,6-linked to a sub-terminal galactose residue.

  20. Comparison of Two Types of Control Structures for Benzene Chlorine Reactive Distillation Systems

    Institute of Scientific and Technical Information of China (English)

    Cuimei Bo; Ridong Zhang; Chenghao Zhang; Jihai Tang; Xu Qiao; Furong Gao

    2014-01-01

    The“neat”operation of the two-reactant reactive distil ation column has better steady-state economics, while it presents a challenge for design, optimization, and control of the process. Based on the optimal economic design, the dual-composition control structure and dual-temperature control structure are designed respectively for the benzene chlorine consecutive reactive distil ation process. The effectiveness and robustness are analyzed compa-rably for the disturbance resistance in terms of changes of production rate and feed composition. Results show that dual-temperature control with propose selection of tray temperatures and the optimal profile of the set point can provide better transient process performance than the composition control structure.