WorldWideScience

Sample records for stable factor structure

  1. Kadison-Kastler stable factors

    DEFF Research Database (Denmark)

    Cameron, Jan; Christensen, Erik; Sinclair, Allan M.

    2014-01-01

    It is proven that a pair of continuous finite von Neumann algebra factors are unitarily equivalent if sufficiently close and one satisfies a certain cohomological condition.......It is proven that a pair of continuous finite von Neumann algebra factors are unitarily equivalent if sufficiently close and one satisfies a certain cohomological condition....

  2. Structure of acid-stable carmine.

    Science.gov (United States)

    Sugimoto, Naoki; Kawasaki, Yoko; Sato, Kyoko; Aoki, Hiromitsu; Ichi, Takahito; Koda, Takatoshi; Yamazaki, Takeshi; Maitani, Tamio

    2002-02-01

    Acid-stable carmine has recently been distributed in the U.S. market because of its good acid stability, but it is not permitted in Japan. We analyzed and determined the structure of the major pigment in acid-stable carmine, in order to establish an analytical method for it. Carminic acid was transformed into a different type of pigment, named acid-stable carmine, through amination when heated in ammonia solution. The features of the structure were clarified using a model compound, purpurin, in which the orientation of hydroxyl groups on the A ring of the anthraquinone skeleton is the same as that of carminic acid. By spectroscopic means and the synthesis of acid-stable carmine and purpurin derivatives, the structure of the major pigment in acid-stable carmine was established as 4-aminocarminic acid, a novel compound.

  3. Longitudinal Tests of Competing Factor Structures for the Rosenberg Self-Esteem Scale: Traits, Ephemeral Artifacts, and Stable Response Styles

    Science.gov (United States)

    Marsh, Herbert W.; Scalas, L. Francesca; Nagengast, Benjamin

    2010-01-01

    Self-esteem, typically measured by the Rosenberg Self-Esteem Scale (RSE), is one of the most widely studied constructs in psychology. Nevertheless, there is broad agreement that a simple unidimensional factor model, consistent with the original design and typical application in applied research, does not provide an adequate explanation of RSE…

  4. Stable Fly, (L., Dispersal and Governing Factors

    Directory of Open Access Journals (Sweden)

    Allan T. Showler

    2015-01-01

    Full Text Available Although the movement of stable fly, Stomoxys calcitrans (L., has been studied, its extent and significance has been uncertain. On a local scale (13 km is mainly wind-driven by weather fronts that carry stable flies from inland farm areas for up to 225 km to beaches of northwestern Florida and Lake Superior. Stable flies can reproduce for a short time each year in washed-up sea grass, but the beaches are not conducive to establishment. Such movement is passive and does not appear to be advantageous to stable fly's survival. On a regional scale, stable flies exhibit little genetic differentiation, and on the global scale, while there might be more than one “lineage”, the species is nevertheless considered to be panmictic. Population expansion across much of the globe likely occurred from the late Pleistocene to the early Holocene in association with the spread of domesticated nomad livestock and particularly with more sedentary, penned livestock.

  5. How structurally stable are global socioeconomic systems?

    Science.gov (United States)

    Saavedra, Serguei; Rohr, Rudolf P; Gilarranz, Luis J; Bascompte, Jordi

    2014-11-06

    The stability analysis of socioeconomic systems has been centred on answering whether small perturbations when a system is in a given quantitative state will push the system permanently to a different quantitative state. However, typically the quantitative state of socioeconomic systems is subject to constant change. Therefore, a key stability question that has been under-investigated is how strongly the conditions of a system itself can change before the system moves to a qualitatively different behaviour, i.e. how structurally stable the systems is. Here, we introduce a framework to investigate the structural stability of socioeconomic systems formed by a network of interactions among agents competing for resources. We measure the structural stability of the system as the range of conditions in the distribution and availability of resources compatible with the qualitative behaviour in which all the constituent agents can be self-sustained across time. To illustrate our framework, we study an empirical representation of the global socioeconomic system formed by countries sharing and competing for multinational companies used as proxy for resources. We demonstrate that the structural stability of the system is inversely associated with the level of competition and the level of heterogeneity in the distribution of resources. Importantly, we show that the qualitative behaviour of the observed global socioeconomic system is highly sensitive to changes in the distribution of resources. We believe that this work provides a methodological basis to develop sustainable strategies for socioeconomic systems subject to constantly changing conditions. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  6. Structure of a Stable G-Hairpin

    Czech Academy of Sciences Publication Activity Database

    Gajarský, M.; Zivkovic, M.L.; Stadlbauer, Petr; Pagano, B.; Fiala, R.; Amato, J.; Tomáška, L´.; Šponer, Jiří; Plavec, J.; Trantírek, L.

    2017-01-01

    Roč. 139, č. 10 (2017), s. 3591-3594 ISSN 0002-7863 R&D Projects: GA ČR GA13-28310S; GA ČR(CZ) GA16-13721S Institutional support: RVO:68081707 Keywords : g-quadruplex structures * human telomeric dna * single-stranded- dna * g-triplex Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 13.858, year: 2016

  7. DFT computations of the lattice constant, stable atomic structure and ...

    African Journals Online (AJOL)

    This paper presents the most stable atomic structure and lattice constant of Fullerenes (C60). FHI-aims DFT code was used to predict the stable structure and the computational lattice constant of C60. These were compared with known experimental structures and lattice constants of C60. The results obtained showed that ...

  8. High precision and stable structures for particle detectors

    CERN Document Server

    Da Mota Silva, S; Hauviller, Claude

    1999-01-01

    The central detectors used in High Energy Physics Experiments require the use of light and stable structures capable of supporting delicate and precise radiation detection elements. These structures need to be highly stable under environmental conditions where external vibrations, high radiation levels, temperature and humidity gradients should be taken into account. Their main design drivers are high dimension and dynamic stability, high stiffness to mass ratio and large radiation length. For most applications, these constraints lead us to choose Carbon Fiber Reinforced Plastics ( CFRP) as structural element. The construction of light and stable structures with CFRP for these applications can be achieved by careful design engineering and further confirmation at the prototyping phase. However, the experimental environment can influence their characteristics and behavior. In this case, theuse of adaptive structures could become a solution for this problem. We are studying structures in CFRP with bonded piezoel...

  9. Dynamics and control of twisting bi-stable structures

    Science.gov (United States)

    Arrieta, Andres F.; van Gemmeren, Valentin; Anderson, Aaron J.; Weaver, Paul M.

    2018-02-01

    Compliance-based morphing structures have the potential to offer large shape adaptation, high stiffness and low weight, while reducing complexity, friction, and scalability problems of mechanism based systems. A promising class of structure that enables these characteristics are multi-stable structures given their ability to exhibit large deflections and rotations without the expensive need for continuous actuation, with the latter only required intermittently. Furthermore, multi-stable structures exhibit inherently fast response due to the snap-through instability governing changes between stable states, enabling rapid configuration switching between the discrete number of programmed shapes of the structure. In this paper, the design and utilisation of the inherent nonlinear dynamics of bi-stable twisting I-beam structures for actuation with low strain piezoelectric materials is presented. The I-beam structure consists of three compliant components assembled into a monolithic single element, free of moving parts, and showing large deflections between two stable states. Finite element analysis is utilised to uncover the distribution of strain across the width of the flange, guiding the choice of positioning for piezoelectric actuators. In addition, the actuation authority is maximised by calculating the generalised coupling coefficient for different positions of the piezoelectric actuators. The results obtained are employed to tailor and test I-beam designs exhibiting desired large deflection between stable states, while still enabling the activation of snap-through with the low strain piezoelectric actuators. To this end, the dynamic response of the I-beams to piezoelectric excitation is investigated, revealing that resonant excitations are insufficient to dynamically trigger snap-through. A novel bang-bang control strategy, which exploits the nonlinear dynamics of the structure successfully triggers both single and constant snap-through between the stable states

  10. Recent developments in low cost stable structures for space

    International Nuclear Information System (INIS)

    Thompson, T.C.; Grastataro, C.; Smith, B.G.

    1994-01-01

    The Los Alamos National Laboratory (LANL) in partnership with Composite Optics Incorporated (COI) is advancing the development of low cost, lightweight, composite technology for use in spacecraft and stable structures. The use of advanced composites is well developed, but the application of an all-composite tracker structure has never been achieved. This paper investigates the application of composite technology to the design and fabrication of an all-composite spacecraft bus for small satellites, using technology directly applicable to central tracking in a high luminosity environment. The satellite program Fast On-Orbit Recording of Transient Events (FORTE) is the second in a series of satellites to be launched into orbit for the US Department of Energy (DOE). This paper will discuss recent developments in the area of low cost composites, used for either spacecraft or ultra stable applications in high energy physics (HEP) detectors. The use of advanced composites is a relatively new development in the area of HEP. The Superconducting Super Collider (SSC) spawned a new generation of Trackers which made extensive use of graphite fiber reinforced plastic (GFRP) composite systems. LANL has designed a structure employing new fabrication technology. This concept will lower the cost of composite structures to a point that they may now compete with conventional materials. This paper will discuss the design, analysis and proposed fabrication of a small satellite structure. Central tracking structures using advanced materials capable of operating in an adverse environment typical of that found in a high luminosity collider could use identical concepts

  11. Highly stable thin film transistors using multilayer channel structure

    KAUST Repository

    Nayak, Pradipta K.

    2015-03-09

    We report highly stable gate-bias stress performance of thin film transistors (TFTs) using zinc oxide (ZnO)/hafnium oxide (HfO2) multilayer structure as the channel layer. Positive and negative gate-bias stress stability of the TFTs was measured at room temperature and at 60°C. A tremendous improvement in gate-bias stress stability was obtained in case of the TFT with multiple layers of ZnO embedded between HfO2 layers compared to the TFT with a single layer of ZnO as the semiconductor. The ultra-thin HfO2 layers act as passivation layers, which prevent the adsorption of oxygen and water molecules in the ZnO layer and hence significantly improve the gate-bias stress stability of ZnO TFTs.

  12. Structure of stable degeneration of K3 surfaces into pairs of rational elliptic surfaces

    OpenAIRE

    Kimura, Yusuke

    2018-01-01

    F-theory/heterotic duality is formulated in the stable degeneration limit of a K3 fibration on the F-theory side. In this note, we analyze the structure of the stable degeneration limit. We discuss whether stable degeneration exists for pairs of rational elliptic surfaces. We demonstrate that, when two rational elliptic surfaces have an identical complex structure, stable degeneration always exists. We provide an equation that systematically describes the stable degeneration of a K3 surface i...

  13. Stable Fly, Stomoxys calcitrans (L.), Dispersal and Governing Factors.

    Science.gov (United States)

    Showler, Allan T; Osbrink, Weste L A

    2015-01-01

    Although the movement of stable fly, Stomoxys calcitrans (L.), has been studied, its extent and significance has been uncertain. On a local scale (fly movement occurs between host animals and resting sites to feed and mate, mainly at on-farm locations where herbivorous livestock regularly congregate. Small numbers emigrate from livestock congregation sites in search of other hosts and oviposition substrate, mostly within stable flies are active year-round in warm latitudes, cold winters in temperate areas result in substantial population and activity declines, limiting movement of any sort to warmer seasons. Long-distance dispersal (>13 km) is mainly wind-driven by weather fronts that carry stable flies from inland farm areas for up to 225 km to beaches of northwestern Florida and Lake Superior. Stable flies can reproduce for a short time each year in washed-up sea grass, but the beaches are not conducive to establishment. Such movement is passive and does not appear to be advantageous to stable fly's survival. On a regional scale, stable flies exhibit little genetic differentiation, and on the global scale, while there might be more than one "lineage", the species is nevertheless considered to be panmictic. Population expansion across much of the globe likely occurred from the late Pleistocene to the early Holocene in association with the spread of domesticated nomad livestock and particularly with more sedentary, penned livestock.

  14. Stable structural color patterns displayed on transparent insect wings.

    Science.gov (United States)

    Shevtsova, Ekaterina; Hansson, Christer; Janzen, Daniel H; Kjærandsen, Jostein

    2011-01-11

    Color patterns play central roles in the behavior of insects, and are important traits for taxonomic studies. Here we report striking and stable structural color patterns--wing interference patterns (WIPs)--in the transparent wings of small Hymenoptera and Diptera, patterns that have been largely overlooked by biologists. These extremely thin wings reflect vivid color patterns caused by thin film interference. The visibility of these patterns is affected by the way the insects display their wings against various backgrounds with different light properties. The specific color sequence displayed lacks pure red and matches the color vision of most insects, strongly suggesting that the biological significance of WIPs lies in visual signaling. Taxon-specific color patterns are formed by uneven membrane thickness, pigmentation, venation, and hair placement. The optically refracted pattern is also stabilized by microstructures of the wing such as membrane corrugations and spherical cell structures that reinforce the pattern and make it essentially noniridescent over a large range of light incidences. WIPs can be applied to map the micromorphology of wings through direct observation and are useful in several fields of biology. We demonstrate their usefulness as identification patterns to solve cases of cryptic species complexes in tiny parasitic wasps, and indicate their potentials for research on the genetic control of wing development through direct links between the transregulatory wing landscape and interference patterns we observe in Drosophila model species. Some species display sexually dimorphic WIPs, suggesting sexual selection as one of the driving forces for their evolution.

  15. Trophic discrimination factors of stable carbon and nitrogen isotopes in hair of corn fed wild boar.

    Directory of Open Access Journals (Sweden)

    Michaela Holá

    Full Text Available Stable isotope measurements are increasingly being used to gain insights into the nutritional ecology of many wildlife species and their role in ecosystem structure and function. Such studies require estimations of trophic discrimination factors (i.e. differences in the isotopic ratio between the consumer and its diet. Although trophic discrimination factors are tissue- and species-specific, researchers often rely on generalized, and fixed trophic discrimination factors that have not been experimentally derived. In this experimental study, captive wild boar (Sus scrofa were fed a controlled diet of corn (Zea mays, a popular and increasingly dominant food source for wild boar in the Czech Republic and elsewhere in Europe, and trophic discrimination factors for stable carbon (Δ13C and nitrogen (Δ15N isotopes were determined from hair samples. The mean Δ13C and Δ15N in wild boar hair were -2.3‰ and +3.5‰, respectively. Also, in order to facilitate future derivations of isotopic measurements along wild boar hair, we calculated the average hair growth rate to be 1.1 mm d(-1. Our results serve as a baseline for interpreting isotopic patterns of free-ranging wild boar in current European agricultural landscapes. However, future research is needed in order to provide a broader understanding of the processes underlying the variation in trophic discrimination factors of carbon and nitrogen across of variety of diet types.

  16. Thermally-Stable High Strain Deployable Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is for the development of a thermally-stable composite made of carbon fibers and elastomeric resin. This combination of materials will allow...

  17. Biological factors of natural and artificial ecosystems stable (unstable) functioning

    Science.gov (United States)

    Pechurkin, Nikolai S.

    The problem of sustainable development of humanity on Earth and the problem of supporting human life in space have the same scientific and methodological bases. The key to solve both problems is a long term maintenance of balanced material cycle. As a whole, natural or artificial ecosystems are to be more closed than open, but their elements (links of systems) are to be substantially open in interactions with each other. Prolonged stable interactions of different links have to have unique joint results - closed material cycling or biotic turnover. It is necessary to include, at least, three types of main links into any system to support real material cycling: producers, consumers, reducers. Producer links are now under studies in many laboratories. It is evident that the higher productivity of link, the lower link stability. Especially, it concerns with parasite impact to plants. As usual, artificial ecosystems are more simple (incomplete) than natural ecosystems, sometimes, they have not enough links for prolonged stable functioning. For example, life support system for space flight can be incomplete in consumer link, having only some crew persons, instead of interacting populations of consumers. As for reducer link, it is necessary to "organize" a special coordinated work of microbial biocenoses to fulfill proper cycling. Possible evolution of links, their self development is a matter of special attention for the maintenance of prolonged stable functioning. It's the most danger for systems with populations of quickly reproducing, so-called, R - strategists, according to symbols of logistic equation. From another side, quick reproduction of R - strategists is able to increase artificial ecosystems and their links functioning. After some damages of system, R - strategist's link can be quickly "self repaired" up to level of normal functioning. Some experimental data of this kind and mathematical models are to be discussed in the paper. This work is supported by

  18. Structure and Dynamics of Thin Ionomer Films: a Key to A Stable Fuel Cell Membrane.

    Science.gov (United States)

    Perahia, Dvora

    2000-03-01

    The technology for solid polymeric electrolytic membranes for a fuel cells, calls for the thinnest film which is electrochemically stable. At present, none supported polymeric solid state fuel cell membranes, thinner than 50 microns, fail mechanically during fuel cell operation. When approaching the thin film limits, interfacial effects become significant to structure dynamics and consequently, the stability of the membranes. Our work focuses on understanding the interfacial effects on thin per-fluorinated ionomer films, including interfacial effects on the thin films themselves and nanotubes-thin film complexes, mimicking the catalyst-ionomer complexes. In particular we investigated the dynamics and structure in 500 angstrom and less, films made by several perfluorinated ionomers, cast on a solid support. Both the films and their parent solutions were investigated with the goal of resolving the factors that affect the stability in the ultra thin regime. AFM/STM and X-ray and neutron reflectivity were used to investigate the thin films and small angle neutron scattering was utilized to the study of the solutions. Films were both spin-coated and self assembles from solutions on a model oxidized single crystal silicon wafer, treated with HF. When coated from molecular solutions, the films tend to dewet on a time scale of minutes to hours. With increasing concentrations, above the critical micellar concentration of the ionomers in water/alcohol, stable films on the order of 200-500 angstroms were formed. While self-assembled films were found to be stable at temperatures close to Tg of the ionomer, spin-coated ones partially dewet. The surface structure obtained, exhibit periodicity on different length scales, depending on the concentration of the polymer in the solution from which the film was assembled. In the ultra dilute regime, micelles were detected at the solid interface. Films formed from dilute solutions exhibit fractal nature with a fractal dimension varying

  19. Factors responsible for a stable biosphere of silicon utilizing organisms

    Science.gov (United States)

    Mitra, D.; Das, S.

    2012-12-01

    -Pg boundary. All these evidences support the role of the unique characteristics of silicon utilizing organisms in maintaining their stable biosphere on earth.

  20. Over all separation factors for stable isotopes by gas centrifuge

    International Nuclear Information System (INIS)

    Chuntong Ying; Nie Yuguang; Zeng Shi; Shang Xiuyong; Wood, Houston G.

    1999-01-01

    The separation factor for the elements with molar wight differences, γ 0 , is an important characteristic parameter for separation of varied isotopes. Besides the dependence on construction parameters of the gas centrifuge it depends on many variables. Some of them are operation conditions, such as feeding flow rate F, pressure at wall p w , temperature T 0 and distribution temperature on the wall and others. Separation factor γ 0 depends on physical properties, such as molar weight M, viscosity μ, product of ρD, where ρ is density of working media and D is its diffusion coefficient. It was taken four examples: UF 6 , WF 6 , OsO 4 and Xe [ru

  1. Structural insights into methanol-stable variants of lipase T6 from Geobacillus stearothermophilus.

    Science.gov (United States)

    Dror, Adi; Kanteev, Margarita; Kagan, Irit; Gihaz, Shalev; Shahar, Anat; Fishman, Ayelet

    2015-11-01

    Enzymatic production of biodiesel by transesterification of triglycerides and alcohol, catalyzed by lipases, offers an environmentally friendly and efficient alternative to the chemically catalyzed process while using low-grade feedstocks. Methanol is utilized frequently as the alcohol in the reaction due to its reactivity and low cost. However, one of the major drawbacks of the enzymatic system is the presence of high methanol concentrations which leads to methanol-induced unfolding and inactivation of the biocatalyst. Therefore, a methanol-stable lipase is of great interest for the biodiesel industry. In this study, protein engineering was applied to substitute charged surface residues with hydrophobic ones to enhance the stability in methanol of a lipase from Geobacillus stearothermophilus T6. We identified a methanol-stable variant, R374W, and combined it with a variant found previously, H86Y/A269T. The triple mutant, H86Y/A269T/R374W, had a half-life value at 70 % methanol of 324 min which reflects an 87-fold enhanced stability compared to the wild type together with elevated thermostability in buffer and in 50 % methanol. This variant also exhibited an improved biodiesel yield from waste chicken oil compared to commercial Lipolase 100L® and Novozyme® CALB. Crystal structures of the wild type and the methanol-stable variants provided insights regarding structure-stability correlations. The most prominent features were the extensive formation of new hydrogen bonds between surface residues directly or mediated by structural water molecules and the stabilization of Zn and Ca binding sites. Mutation sites were also characterized by lower B-factor values calculated from the X-ray structures indicating improved rigidity.

  2. Hygro-Thermal Transient Analysis for Highly Stable Structures

    CERN Document Server

    Da Mota Silva, S; Hauviller, Claude; Kanoute, P; Ribeiro, R

    1999-01-01

    This paper presents the results obtained with the simulations of a sandwich rectangular plate made of carbon/epoxy composite when subjected to temperature and humidity cycles. Fickian diffusion process, moisture transport along the interfaces and damage caused by slipping and debonding between the components of the microscopic structure are considered. The application of the design methodology to a real structure is shown.

  3. Trophic structure in a seabird host-parasite food web: insights from stable isotope analyses.

    Directory of Open Access Journals (Sweden)

    Elena Gómez-Díaz

    2010-05-01

    Full Text Available Ecological studies on food webs rarely include parasites, partly due to the complexity and dimensionality of host-parasite interaction networks. Multiple co-occurring parasites can show different feeding strategies and thus lead to complex and cryptic trophic relationships, which are often difficult to disentangle by traditional methods. We analyzed stable isotope ratios of C ((13C/(12C, delta(13C and N ((15N/(14N, delta(15N of host and ectoparasite tissues to investigate trophic structure in 4 co-occurring ectoparasites: three lice and one flea species, on two closely related and spatially segregated seabird hosts (Calonectris shearwaters. delta(13C isotopic signatures confirmed feathers as the main food resource for the three lice species and blood for the flea species. All ectoparasite species showed a significant enrichment in delta(15N relatively to the host tissue consumed (discrimination factors ranged from 2 to 5 per thousand depending on the species. Isotopic differences were consistent across multiple host-ectoparasite locations, despite of some geographic variability in baseline isotopic levels. Our findings illustrate the influence of both ectoparasite and host trophic ecology in the isotopic structuring of the Calonectris ectoparasite community. This study highlights the potential of stable isotope analyses in disentangling the nature and complexity of trophic relationships in symbiotic systems.

  4. Active structural control with stable fuzzy PID techniques

    CERN Document Server

    Yu, Wen

    2016-01-01

    This book presents a detailed discussion of intelligent techniques to measure the displacement of buildings when they are subjected to vibration. It shows how these techniques are used to control active devices that can reduce vibration 60–80% more effectively than widely used passive anti-seismic systems. After introducing various structural control devices and building-modeling and active structural control methods, the authors propose offset cancellation and high-pass filtering techniques to solve some common problems of building-displacement measurement using accelerometers. The most popular control algorithms in industrial settings, PD/PID controllers, are then analyzed and then combined with fuzzy compensation. The stability of this combination is proven with standard weight-training algorithms. These conditions provide explicit methods for selecting PD/PID controllers. Finally, fuzzy-logic and sliding-mode control are applied to the control of wind-induced vibration. The methods described are support...

  5. An Energy stable Monolithic Eulerian Fluid-Structure Numerical Scheme *

    OpenAIRE

    Pironneau , Olivier

    2017-01-01

    The conservation laws of continuum mechanic written in an Eulerian frame make no difference between fluids and solids except in the expression of the stress tensors, usually with Newton's hypothesis for the fluids and Helmholtz potentials of energy for hyperelastic solids. By taking the velocities as unknown , monolithic methods for fluid structure interactions (FSI) are built. In this article such a formulation is analyzed when the fluid is compressible and the fluid is incompressible. The i...

  6. Crystalline mesoporous zirconia catalysts having stable tetragonal pore wall structure

    Science.gov (United States)

    Sachtler, Wolfgang M. H.; Huang, Yin-Yan

    1998-01-01

    Methods for the preparation of new sulfated mesoporous zirconia materials/catalysts with crystalline pore walls of predominantly tetragonal crystal structure, characterized by nitrogen physisorption measurement, X-ray diffraction, transmission electron microscopy and catalytic tests using n-butane isomerization to iso-butane and alkylation of 1-naphthol with 4-tert-butylstyrene as probe reactions. Sulfate deposition is preferred for the transformation of a mesoporous precursor with amorphous pore walls into a material with crystalline pore walls maintaining the mesoporous characteristics.

  7. Numerically stable fluid–structure interactions between compressible flow and solid structures

    KAUST Repository

    Grétarsson, Jón Tómas

    2011-04-01

    We propose a novel method to implicitly two-way couple Eulerian compressible flow to volumetric Lagrangian solids. The method works for both deformable and rigid solids and for arbitrary equations of state. The method exploits the formulation of [11] which solves compressible fluid in a semi-implicit manner, solving for the advection part explicitly and then correcting the intermediate state to time tn+1 using an implicit pressure, obtained by solving a modified Poisson system. Similar to previous fluid-structure interaction methods, we apply pressure forces to the solid and enforce a velocity boundary condition on the fluid in order to satisfy a no-slip constraint. Unlike previous methods, however, we apply these coupled interactions implicitly by adding the constraint to the pressure system and combining it with any implicit solid forces in order to obtain a strongly coupled, symmetric indefinite system (similar to [17], which only handles incompressible flow). We also show that, under a few reasonable assumptions, this system can be made symmetric positive-definite by following the methodology of [16]. Because our method handles the fluid-structure interactions implicitly, we avoid introducing any new time step restrictions and obtain stable results even for high density-to-mass ratios, where explicit methods struggle or fail. We exactly conserve momentum and kinetic energy (thermal fluid-structure interactions are not considered) at the fluid-structure interface, and hence naturally handle highly non-linear phenomenon such as shocks, contacts and rarefactions. © 2011 Elsevier Inc.

  8. Spatial variations in food web structures with alternative stable states: evidence from stable isotope analysis in a large eutrophic lake

    Science.gov (United States)

    Li, Yunkai; Zhang, Yuying; Xu, Jun; Zhang, Shuo

    2017-05-01

    Food web structures are well known to vary widely among ecosystems. Moreover, many food web studies of lakes have generally attempted to characterize the overall food web structure and have largely ignored internal spatial and environmental variations. In this study, we hypothesize that there is a high degree of spatial heterogeneity within an ecosystem and such heterogeneity may lead to strong variations in environmental conditions and resource availability, in turn resulting in different trophic pathways. Stable carbon and nitrogen isotopes were employed for the whole food web to describe the structure of the food web in different sub-basins within Taihu Lake. This lake is a large eutrophic freshwater lake that has been intensively managed and highly influenced by human activities for more than 50 years. The results show significant isotopic differences between basins with different environmental characteristics. Such differences likely result from isotopic baseline differences combining with a shift in food web structure. Both are related to local spatial heterogeneity in nutrient loading in waters. Such variation should be explicitly considered in future food web studies and ecosystem-based management in this lake ecosystem.

  9. Regional Comparisons of Oceanic Food Web Structure Using Stable Isotopes

    Science.gov (United States)

    Choy, A.; Drazen, J.; Popp, B. N.; Robison, B. H.

    2016-02-01

    Food chain length, or the number of trophic steps between primary producers and apex predators within an ecosystem, is a key determinant of ecosystem structure, including overall efficiency, stability, and productivity. Here, we quantitatively estimate food chain length for three pelagic ecosystems characterized by distinct biogeochemical and oceanographic regimes: the Northern California Current (NCC), the North Pacific Subtropical Gyre (NPSG), and the Gulf of California (GoC). From each region, ecologically equivalent organisms were selected from each of four successive trophic steps, including zooplankton (primary consumers), zooplanktivores (secondary consumers), piscivores (tertiary consumers), and higher order predators. Bulk tissue δ15N values of the organisms from all four trophic steps spanned ranges of approximately 9.8‰ (NCC), 1.4‰ (NPSG), and 2.1‰ (GoC). Regional variations in nitrogen biogeochemistry, however, can alter isotopic baselines and food web dynamics, ultimately complicating bulk isotope measurements across regions. Thus, we apply amino acid nitrogen isotope measurements to quantitatively measure and compare food chain length across consumers from the three regions, accounting for biogeochemical disparities in isotopic baseline. Implications for ecosystem production and efficiency are discussed, including the potential for these different ecosystems to withstand environmental change, including shifting oxygen levels and surface productivity.

  10. Tissue Factor Structure and Function

    Directory of Open Access Journals (Sweden)

    Saulius Butenas

    2012-01-01

    Full Text Available Tissue factor (TF is an integral membrane protein that is essential to life. It is a component of the factor VIIa-TF complex enzyme and plays a primary role in both normal hemostasis and thrombosis. With a vascular injury, TF becomes exposed to blood and binds plasma factor VIIa, and the resulting complex initiates a series of enzymatic reactions leading to clot formation and vascular sealing. Many cells, both healthy, and tumor cells, produce detectable amounts of TF, especially when they are stimulated by various agents. Despite the relative simplicity and small size of TF, there are numerous contradictory reports about the synthesis and presentation of TF on blood cells and circulation in normal blood either on microparticles or as a soluble protein. Another subject of controversy is related to the structure/function of TF. It has been almost commonly accepted that cell-surface-associated TF has low (if any activity, that is, is “encrypted” and requires specific conditions/reagents to become active, that is, “decrypted.” However there is a lack of agreement related to the mechanism and processes leading to alterations in TF function. In this paper TF structure, presentation, and function, and controversies concerning these features are discussed.

  11. TGP, an extremely stable, non-aggregating fluorescent protein created by structure-guided surface engineering

    OpenAIRE

    Close, Devin W.; Don Paul, Craig; Langan, Patricia S.; Wilce, Matthew C.J.; Traore, Daouda A.K.; Halfmann, Randal; Rocha, Reginaldo C.; Waldo, Geoffery S.; Payne, Riley J.; Rucker, Joseph B.; Prescott, Mark; Bradbury, Andrew R.M.

    2015-01-01

    In this paper we describe the engineering and X-ray crystal structure of Thermal Green Protein (TGP), an extremely stable, highly soluble, non-aggregating green fluorescent protein. TGP is a soluble variant of the fluorescent protein eCGP123, which despite being highly stable, has proven to be aggregation-prone. The X-ray crystal structure of eCGP123, also determined within the context of this paper, was used to carry out rational surface engineering to improve its solubility, leading to TGP....

  12. Structure of stable degeneration of K3 surfaces into pairs of rational elliptic surfaces

    Science.gov (United States)

    Kimura, Yusuke

    2018-03-01

    F-theory/heterotic duality is formulated in the stable degeneration limit of a K3 fibration on the F-theory side. In this note, we analyze the structure of the stable degeneration limit. We discuss whether stable degeneration exists for pairs of rational elliptic surfaces. We demonstrate that, when two rational elliptic surfaces have an identical complex structure, stable degeneration always exists. We provide an equation that systematically describes the stable degeneration of a K3 surface into a pair of isomorphic rational elliptic surfaces. When two rational elliptic surfaces have different complex structures, whether their sum glued along a smooth fiber admits deformation to a K3 surface can be determined by studying the structure of the K3 lattice. We investigate the lattice theoretic condition to determine whether a deformation to a K3 surface exists for pairs of extremal rational elliptic surfaces. In addition, we discuss the configurations of singular fibers under stable degeneration. The sum of two isomorphic rational elliptic surfaces glued together admits a deformation to a K3 surface, the singular fibers of which are twice that of the rational elliptic surface. For special situations, singular fibers of the resulting K3 surface collide and they are enhanced to a fiber of another type. Some K3 surfaces become attractive in these situations. We determine the complex structures and the Weierstrass forms of these attractive K3 surfaces. We also deduce the gauge groups in F-theory compactifications on these attractive K3 surfaces times a K3. E 6, E 7, E 8, SU(5), and SO(10) gauge groups arise in these compactifications.

  13. Novel stable structure of Li3PS4 predicted by evolutionary algorithm under high-pressure

    Directory of Open Access Journals (Sweden)

    S. Iikubo

    2018-01-01

    Full Text Available By combining theoretical predictions and in-situ X-ray diffraction under high pressure, we found a novel stable crystal structure of Li3PS4 under high pressures. At ambient pressure, Li3PS4 shows successive structural transitions from γ-type to β-type and from β-type to α type with increasing temperature, as is well established. In this study, an evolutionary algorithm successfully predicted the γ-type crystal structure at ambient pressure and further predicted a possible stable δ-type crystal structures under high pressure. The stability of the obtained structures is examined in terms of both static and dynamic stability by first-principles calculations. In situ X-ray diffraction using a synchrotron radiation revealed that the high-pressure phase is the predicted δ-Li3PS4 phase.

  14. The structure factor of primes

    Science.gov (United States)

    Zhang, G.; Martelli, F.; Torquato, S.

    2018-03-01

    Although the prime numbers are deterministic, they can be viewed, by some measures, as pseudo-random numbers. In this article, we numerically study the pair statistics of the primes using statistical-mechanical methods, particularly the structure factor S(k) in an interval M ≤slant p ≤slant M + L with M large, and L/M smaller than unity. We show that the structure factor of the prime-number configurations in such intervals exhibits well-defined Bragg-like peaks along with a small ‘diffuse’ contribution. This indicates that primes are appreciably more correlated and ordered than previously thought. Our numerical results definitively suggest an explicit formula for the locations and heights of the peaks. This formula predicts infinitely many peaks in any non-zero interval, similar to the behavior of quasicrystals. However, primes differ from quasicrystals in that the ratio between the location of any two predicted peaks is rational. We also show numerically that the diffuse part decays slowly as M and L increases. This suggests that the diffuse part vanishes in an appropriate infinite-system-size limit.

  15. Discrimination factors of carbon and nitrogen stable isotopes in meerkat feces

    Directory of Open Access Journals (Sweden)

    Shaena Montanari

    2017-06-01

    Full Text Available Stable isotope analysis of feces can provide a non-invasive method for tracking the dietary habits of nearly any mammalian species. While fecal samples are often collected for macroscopic and genetic study, stable isotope analysis can also be applied to expand the knowledge of species-specific dietary ecology. It is somewhat unclear how digestion changes the isotope ratios of animals’ diets, so more controlled diet studies are needed. To date, most diet-to-feces controlled stable isotope experiments have been performed on herbivores, so in this study I analyzed the carbon and nitrogen stable isotope ratios in the diet and feces of the meerkat (Suricata suricatta, a small omnivorous mammal. The carbon trophic discrimination factor between diet and feces (Δ13Cfeces is calculated to be 0.1 ± 1.5‰, which is not significantly different from zero, and in turn, not different than the dietary input. On the other hand, the nitrogen trophic discrimination factor (Δ15Nfeces is 1.5 ± 1.1‰, which is significantly different from zero, meaning it is different than the average dietary input. Based on data generated in this experiment and a review of the published literature, carbon isotopes of feces characterize diet, while nitrogen isotope ratios of feces are consistently higher than dietary inputs, meaning a discrimination factor needs to be taken into account. The carbon and nitrogen stable isotope values of feces are an excellent snapshot of diet that can be used in concert with other analytical methods to better understand ecology, diets, and habitat use of mammals.

  16. Discrimination factors of carbon and nitrogen stable isotopes in meerkat feces

    Science.gov (United States)

    2017-01-01

    Stable isotope analysis of feces can provide a non-invasive method for tracking the dietary habits of nearly any mammalian species. While fecal samples are often collected for macroscopic and genetic study, stable isotope analysis can also be applied to expand the knowledge of species-specific dietary ecology. It is somewhat unclear how digestion changes the isotope ratios of animals’ diets, so more controlled diet studies are needed. To date, most diet-to-feces controlled stable isotope experiments have been performed on herbivores, so in this study I analyzed the carbon and nitrogen stable isotope ratios in the diet and feces of the meerkat (Suricata suricatta), a small omnivorous mammal. The carbon trophic discrimination factor between diet and feces (Δ13Cfeces) is calculated to be 0.1 ± 1.5‰, which is not significantly different from zero, and in turn, not different than the dietary input. On the other hand, the nitrogen trophic discrimination factor (Δ15Nfeces) is 1.5 ± 1.1‰, which is significantly different from zero, meaning it is different than the average dietary input. Based on data generated in this experiment and a review of the published literature, carbon isotopes of feces characterize diet, while nitrogen isotope ratios of feces are consistently higher than dietary inputs, meaning a discrimination factor needs to be taken into account. The carbon and nitrogen stable isotope values of feces are an excellent snapshot of diet that can be used in concert with other analytical methods to better understand ecology, diets, and habitat use of mammals. PMID:28626611

  17. Stable preparations of tyrosine hydroxylase provide the solution structure of the full-length enzyme

    Science.gov (United States)

    Bezem, Maria T.; Baumann, Anne; Skjærven, Lars; Meyer, Romain; Kursula, Petri; Martinez, Aurora; Flydal, Marte I.

    2016-01-01

    Tyrosine hydroxylase (TH) catalyzes the rate-limiting step in the biosynthesis of catecholamine neurotransmitters. TH is a highly complex enzyme at mechanistic, structural, and regulatory levels, and the preparation of kinetically and conformationally stable enzyme for structural characterization has been challenging. Here, we report on improved protocols for purification of recombinant human TH isoform 1 (TH1), which provide large amounts of pure, stable, active TH1 with an intact N-terminus. TH1 purified through fusion with a His-tagged maltose-binding protein on amylose resin was representative of the iron-bound functional enzyme, showing high activity and stabilization by the natural feedback inhibitor dopamine. TH1 purified through fusion with a His-tagged ZZ domain on TALON is remarkably stable, as it was partially inhibited by resin-derived cobalt. This more stable enzyme preparation provided high-quality small-angle X-ray scattering (SAXS) data and reliable structural models of full-length tetrameric TH1. The SAXS-derived model reveals an elongated conformation (Dmax = 20 nm) for TH1, different arrangement of the catalytic domains compared with the crystal structure of truncated forms, and an N-terminal region with an unstructured tail that hosts the phosphorylation sites and a separated Ala-rich helical motif that may have a role in regulation of TH by interacting with binding partners. PMID:27462005

  18. DNA-based stable isotope probing: a link between community structure and function

    Czech Academy of Sciences Publication Activity Database

    Uhlík, Ondřej; Ječná, K.; Leigh, M. B.; Macková, Martina; Macek, Tomáš

    2009-01-01

    Roč. 407, č. 12 (2009), s. 3611-3619 ISSN 0048-9697 Grant - others:GA MŠk(CZ) 2B08031 Program:2B Institutional research plan: CEZ:AV0Z40550506 Keywords : DNA-based stable isotope probing * microbial diversity * bioremediation Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.905, year: 2009

  19. Recent Bayesian stable-isotope mixing models are highly sensitive to variation in discrimination factors.

    Science.gov (United States)

    Bond, Alexander L; Diamond, Antony W

    2011-06-01

    Stable isotopes are now used widely in ecological studies, including diet reconstruction, where quantitative inferences about diet composition are derived from the use of mixing models. Recent Bayesian models (MixSIR, SIAR) allow users to incorporate variability in discrimination factors (delta13C or delta15N), or the amount of change in either delta13C or delta15N between prey and consumer, but to date there has been no systematic assessment of the effect of variation in delta13C or delta15N on model outputs. We used whole blood from Common Terns (Sterna hirundo) and muscle from their common prey items (fish and euphausiids) to build a series of mixing models in SIAR (stable isotope analysis in R) using various discrimination factors from the published literature for marine birds. The estimated proportion of each diet component was affected significantly by delta13C or delta15N. We also use recently published stable-isotope data on the reliance of critically endangered Balearic Shearwaters (Puffinus mauretanicus) on fisheries discards to show that discrimination factor choice can have profound implications for conservation and management actions. It is therefore crucial for researchers wishing to use mixing models to have an accurate estimate of delta13C and delta15N, because quantitative diet estimates can help to direct future research or prioritize conservation and management actions.

  20. Embodied memory: effective and stable perception by combining optic flow and image structure.

    Science.gov (United States)

    Pan, Jing Samantha; Bingham, Ned; Bingham, Geoffrey P

    2013-12-01

    Visual perception studies typically focus either on optic flow structure or image structure, but not on the combination and interaction of these two sources of information. Each offers unique strengths in contrast to the other's weaknesses. Optic flow yields intrinsically powerful information about 3D structure, but is ephemeral. It ceases when motion stops. Image structure is less powerful in specifying 3D structure, but is stable. It remains when motion stops. Optic flow and image structure are intrinsically related in vision because the optic flow carries one image to the next. This relation is especially important in the context of progressive occlusion, in which optic flow provides information about the location of targets hidden in subsequent image structure. In four experiments, we investigated the role of image structure in "embodied memory" in contrast to memory that is only in the head. We found that either optic flow (Experiment 1) or image structure (Experiment 2) alone were relatively ineffective, whereas the combination was effective and, in contrast to conditions requiring reliance on memory-in-the-head, much more stable over extended time (Experiments 2 through 4). Limits well documented for visual short memory (that is, memory-in-the-head) were strongly exceeded by embodied memory. The findings support J. J. Gibson's (1979/1986, The Ecological Approach to Visual Perception, Boston, MA, Houghton Mifflin) insights about progressive occlusion and the embodied nature of perception and memory.

  1. Prediction of Stable Ruthenium Silicides from First-Principles Calculations: Stoichiometries, Crystal Structures, and Physical Properties.

    Science.gov (United States)

    Zhang, Chuanzhao; Kuang, Xiaoyu; Jin, Yuanyuan; Lu, Cheng; Zhou, Dawei; Li, Peifang; Bao, Gang; Hermann, Andreas

    2015-12-09

    We present results of an unbiased structure search for stable ruthenium silicide compounds with various stoichiometries, using a recently developed technique that combines particle swarm optimization algorithms with first-principles calculations. Two experimentally observed structures of ruthenium silicides, RuSi (space group P2(1)3) and Ru2Si3 (space group Pbcn), are successfully reproduced under ambient pressure conditions. In addition, a stable RuSi2 compound with β-FeSi2 structure type (space group Cmca) was found. The calculations of the formation enthalpy, elastic constants, and phonon dispersions demonstrate the Cmca-RuSi2 compound is energetically, mechanically, and dynamically stable. The analysis of electronic band structures and densities of state reveals that the Cmca-RuSi2 phase is a semiconductor with a direct band gap of 0.480 eV and is stabilized by strong covalent bonding between Ru and neighboring Si atoms. On the basis of the Mulliken overlap population analysis, the Vickers hardness of the Cmca structure RuSi2 is estimated to be 28.0 GPa, indicating its ultra-incompressible nature.

  2. Stable isotope applications in biomolecular structure and mechanisms. A meeting to bring together producers and users of stable-isotope-labeled compounds to assess current and future needs

    Energy Technology Data Exchange (ETDEWEB)

    Trewhella, J.; Cross, T.A.; Unkefer, C.J. [eds.

    1994-12-01

    Knowledge of biomolecular structure is a prerequisite for understanding biomolecular function, and stable isotopes play an increasingly important role in structure determination of biological molecules. The first Conference on Stable Isotope Applications in Biomolecular Structure and Mechanisms was held in Santa Fe, New Mexico, March 27--31, 1994. More than 120 participants from 8 countries and 44 institutions reviewed significant developments, discussed the most promising applications for stable isotopes, and addressed future needs and challenges. Participants focused on applications of stable isotopes for studies of the structure and function of proteins, peptides, RNA, and DNA. Recent advances in NMR techniques neutron scattering, EPR, and vibrational spectroscopy were highlighted in addition to the production and synthesis of labeled compounds. This volume includes invited speaker and poster presentations as well as a set of reports from discussion panels that focused on the needs of the scientific community and the potential roles of private industry, the National Stable Isotope Resource, and the National High Magnetic Field Laboratory in serving those needs. This is the leading abstract. Individual papers are processed separately for the database.

  3. Stable isotope applications in biomolecular structure and mechanisms. A meeting to bring together producers and users of stable-isotope-labeled compounds to assess current and future needs

    International Nuclear Information System (INIS)

    Trewhella, J.; Cross, T.A.; Unkefer, C.J.

    1994-12-01

    Knowledge of biomolecular structure is a prerequisite for understanding biomolecular function, and stable isotopes play an increasingly important role in structure determination of biological molecules. The first Conference on Stable Isotope Applications in Biomolecular Structure and Mechanisms was held in Santa Fe, New Mexico, March 27--31, 1994. More than 120 participants from 8 countries and 44 institutions reviewed significant developments, discussed the most promising applications for stable isotopes, and addressed future needs and challenges. Participants focused on applications of stable isotopes for studies of the structure and function of proteins, peptides, RNA, and DNA. Recent advances in NMR techniques neutron scattering, EPR, and vibrational spectroscopy were highlighted in addition to the production and synthesis of labeled compounds. This volume includes invited speaker and poster presentations as well as a set of reports from discussion panels that focused on the needs of the scientific community and the potential roles of private industry, the National Stable Isotope Resource, and the National High Magnetic Field Laboratory in serving those needs. This is the leading abstract. Individual papers are processed separately for the database

  4. Dipolar Quinoidal Acene Analogues as Stable Isoelectronic Structures of Pentacene and Nonacene

    KAUST Repository

    Shi, Xueliang

    2015-10-08

    Quinoidal thia-acene analogues, as the respective isoelectronic structures of pentacene and nonacene, were synthesized and an unusual 1,2-sulfur migration was observed during the Friedel-Crafts alkylation reaction. The analogues display a closed-shell quinoidal structure in the ground state with a distinctive dipolar character. In contrast to their acene isoelectronic structures, both compounds are stable because of the existence of more aromatic sextet rings, a dipolar character, and kinetic blocking. They exhibit unique packing in single crystals resulting from balanced dipole-dipole and [C-H⋯π]/[C-H⋯S] interactions.

  5. Stable algorithm for the computation of the electromagnetic field distribution of eigenmodes of periodic diffraction structures.

    Science.gov (United States)

    Bezus, Evgeni A; Doskolovich, Leonid L

    2012-11-01

    In the present work, a stable algorithm for the calculation of the electromagnetic field distributions of the eigenmodes of one-dimensional diffraction gratings is presented. The proposed approach is based on the method for the computation of the propagation constants of Bloch waves of such structures previously presented by Cao et al.[J. Opt. Soc. Am. A 19, 335 (2002)] and uses a modified S-matrix algorithm to ensure numerical stability.

  6. Muon-Substituted Malonaldehyde: Transforming a Transition State into a Stable Structure by Isotope Substitution.

    Science.gov (United States)

    Goli, Mohammad; Shahbazian, Shant

    2016-02-12

    Isotope substitutions are usually conceived to play a marginal role on the structure and bonding pattern of molecules. However, a recent study [Angew. Chem. Int. Ed. 2014, 53, 13706-13709; Angew. Chem. 2014, 126, 13925-13929] further demonstrates that upon replacing a proton with a positively charged muon, as the lightest radioisotope of hydrogen, radical changes in the nature of the structure and bonding of certain species may take place. The present report is a primary attempt to introduce another example of structural transformation on the basis of the malonaldehyde system. Accordingly, upon replacing the proton between the two oxygen atoms of malonaldehyde with the positively charged muon a serious structural transformation is observed. By using the ab initio nuclear-electronic orbital non-Born-Oppenheimer procedure, the nuclear configuration of the muon-substituted species is derived. The resulting nuclear configuration is much more similar to the transition state of the proton transfer in malonaldehyde rather than to the stable configuration of malonaldehyde. The comparison of the "atoms in molecules" (AIM) structure of the muon-substituted malonaldehyde and the AIM structure of the stable and the transition-state configurations of malonaldehyde also unequivocally demonstrates substantial similarities of the muon-substituted malonaldehyde to the transition state. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Comparing Factor Structures of Adolescent Psychopathology

    Science.gov (United States)

    Verona, Edelyn; Javdani, Shabnam; Sprague, Jenessa

    2011-01-01

    Research on the structure of adolescent psychopathology can provide information on broad factors that underlie different forms of maladjustment in youths. Multiple studies from the literature on adult populations suggest that 2 factors, Internalizing and Externalizing, meaningfully comprise the factor structure of adult psychopathology (e.g.,…

  8. Stable Encoding of Task Structure Coexists With Flexible Coding of Task Events in Sensorimotor Striatum

    Science.gov (United States)

    Kubota, Yasuo; Liu, Jun; Hu, Dan; DeCoteau, William E.; Eden, Uri T.; Smith, Anne C.

    2009-01-01

    The sensorimotor striatum, as part of the brain's habit circuitry, has been suggested to store fixed action values as a result of stimulus-response learning and has been contrasted with a more flexible system that conditionally assigns values to behaviors. The stability of neural activity in the sensorimotor striatum is thought to underlie not only normal habits but also addiction and clinical syndromes characterized by behavioral fixity. By recording in the sensorimotor striatum of mice, we asked whether neuronal activity acquired during procedural learning would be stable even if the sensory stimuli triggering the habitual behavior were altered. Contrary to expectation, both fixed and flexible activity patterns appeared. One, representing the global structure of the acquired behavior, was stable across changes in task cuing. The second, a fine-grain representation of task events, adjusted rapidly. Such dual forms of representation may be critical to allow motor and cognitive flexibility despite habitual performance. PMID:19625536

  9. Benthic Food Web Structure across the Canadian Arctic Ocean: Insights from stable isotopes and the IP25 biomarker

    Science.gov (United States)

    Friscourt, N.; Archambault, P.; Masse, G.; Nozais, C.

    2016-02-01

    In recent decades, the Arctic Ocean has undergone unprecedented changes, such as an increase in the surface temperature and a reduction of sea ice cover. These changes may cause variations in the intensity and spatial distribution of primary production and the nature of pelagic-benthic coupling. This could affect the amount and quality of organic matter that settles onto the seafloor, and the benthic communities that feed upon it. The objectives of this study were i) to describe the trophic structure and resilience of regional benthic food webs using stable carbon and nitrogen isotope analyses and ii) to evaluate the significance of ice algae in the diet of benthic communities using the sea ice proxy IP25. The study area extends from the North Water Polynya to the Chukchi Sea across five geographic regions (North Water Polynya, Canadian Archipelago, Amundsen Gulf, Beaufort Sea and Chukchi Sea) based on environmental factors. To reach these objectives, we collected particulate organic matter (POM), sediments and zoobenthic samples from July to October 2014 aboard the CCGS Amundsen. Stable isotope and IP25 data, the trophic structure within regions and comparison between regions will be presented. Potential impacts of climate change and human activities on benthic ecosystems in the Arctic are still difficult to assess because of the lack of baseline data. The baseline data once provided will enable us to make further predictions on how these changes may affect benthic food web structure.

  10. TGP, an extremely stable, non-aggregating fluorescent protein created by structure-guided surface engineering

    Science.gov (United States)

    Close, Devin W.; Don Paul, Craig; Langan, Patricia S.; Wilce, Matthew C.J.; Traore, Daouda A.K.; Halfmann, Randal; Rocha, Reginaldo C.; Waldo, Geoffery S.; Payne, Riley J.; Rucker, Joseph B.; Prescott, Mark; Bradbury, Andrew R.M.

    2014-01-01

    In this paper we describe the engineering and X-ray crystal structure of Thermal Green Protein (TGP), an extremely stable, highly soluble, non-aggregating green fluorescent protein. TGP is a soluble variant of the fluorescent protein eCGP123, which despite being highly stable, has proven to be aggregation-prone. The X-ray crystal structure of eCGP123, also determined within the context of this paper, was used to carry out rational surface engineering to improve its solubility, leading to TGP. The approach involved simultaneously eliminating crystal lattice contacts while increasing the overall negative charge of the protein. Despite intentional disruption of lattice contacts and introduction of high entropy glutamate side chains, TGP crystallized readily in a number of different conditions and the X-ray crystal structure of TGP was determined to 1.9 Å resolution. The structural reasons for the enhanced stability of TGP and eCGP123 are discussed. We demonstrate the utility of using TGP as a fusion partner in various assays and significantly, in amyloid assays in which the standard fluorescent protein, EGFP, is undesirable because of aberrant oligomerization. PMID:25287913

  11. Thermal green protein, an extremely stable, nonaggregating fluorescent protein created by structure-guided surface engineering.

    Science.gov (United States)

    Close, Devin W; Paul, Craig Don; Langan, Patricia S; Wilce, Matthew C J; Traore, Daouda A K; Halfmann, Randal; Rocha, Reginaldo C; Waldo, Geoffery S; Payne, Riley J; Rucker, Joseph B; Prescott, Mark; Bradbury, Andrew R M

    2015-07-01

    In this article, we describe the engineering and X-ray crystal structure of Thermal Green Protein (TGP), an extremely stable, highly soluble, non-aggregating green fluorescent protein. TGP is a soluble variant of the fluorescent protein eCGP123, which despite being highly stable, has proven to be aggregation-prone. The X-ray crystal structure of eCGP123, also determined within the context of this paper, was used to carry out rational surface engineering to improve its solubility, leading to TGP. The approach involved simultaneously eliminating crystal lattice contacts while increasing the overall negative charge of the protein. Despite intentional disruption of lattice contacts and introduction of high entropy glutamate side chains, TGP crystallized readily in a number of different conditions and the X-ray crystal structure of TGP was determined to 1.9 Å resolution. The structural reasons for the enhanced stability of TGP and eCGP123 are discussed. We demonstrate the utility of using TGP as a fusion partner in various assays and significantly, in amyloid assays in which the standard fluorescent protein, EGFP, is undesirable because of aberrant oligomerization. © 2014 Wiley Periodicals, Inc.

  12. The search for the most stable structures of silicon-carbon monolayer compounds.

    Science.gov (United States)

    Li, Pengfei; Zhou, Rulong; Zeng, Xiao Cheng

    2014-10-21

    The most stable structures of two-dimensional (2D) silicon-carbon monolayer compounds with different stoichiometric compositions (i.e., Si : C ratio = 2 : 3, 1 : 3 and 1 : 4) are predicted for the first time based on the particle-swarm optimization (PSO) technique combined with density functional theory optimization. Although the 2D Si-C monolayer compounds considered here are rich in carbon, many of the low-energy metastable and the lowest-energy silicon-carbon structures are not graphene (carbon monolayer) like. Phonon-spectrum calculations and ab initio molecular dynamics simulations were also performed to confirm the dynamical stability of the predicted most stable 2D silicon-carbon structures as well their thermal stability at elevated temperature. The computed electronic band structures show that all three predicted silicon-carbon compounds are semiconductors with direct or indirect bandgaps. Importantly, their bandgaps are predicted to be close to those of bulk silicon or bulk germanium. If confirmed in the laboratory, these 2D silicon-carbon compounds with different stoichiometric compositions may be exploited for future applications in nanoelectronic devices.

  13. Structurally stable gel bead containing entrapped enzyme and method for manufacture thereof

    Science.gov (United States)

    Woodward, J.

    1998-12-08

    This research provides a structurally stable gel bead containing an entrapped enzyme and a method for its manufacture. The enzyme is covalently cross-linked to gelatin in the presence of glutaraldehyde prior to the formation of the gel bead, to prevent leakage of the enzyme. Propylene glycol alginate is then added to the mixture. Once the gel beads are formed, they are then soaked in glutaraldehyde, which imparts structural stability to the gel beads. This method can be used with many types of enzymes, such as proteases, carbohydrases, proteases, ligases, isomerases, oxidoreductases, and specialty enzymes. These and other enzymes can be immobilized in the gel beads and utilized in a number of enzymatic processes. Exogenously added ions are not required to maintain the structural stability of these gel beads. 7 figs.

  14. Factor Structure of the Profile of Mood States (POMS): Two Partial Replications.

    Science.gov (United States)

    Norcross, John C.; And Others

    1984-01-01

    Examined the factor structure of the Profile of Mood States (POMS) in samples of psychiatric outpatients (N=165) and adult smokers (N=298). Results indicated that the POMS appears to be an internally consistent, multidimensional instrument with a relatively stable factor structure. (LLL)

  15. Rich stoichiometries of stable Ca-Bi system: Structure prediction and superconductivity

    Science.gov (United States)

    Dong, Xu; Fan, Changzeng

    2015-03-01

    Using a variable-composition ab initio evolutionary algorithm implemented in the USPEX code, we have performed a systematic search for stable compounds in the Ca-Bi system at different pressures. In addition to the well-known tI12-Ca2Bi and oS12-CaBi2, a few more structures were found by our calculations, among which phase transitions were also predicted in Ca2Bi (tI12 --> oI12 --> hP6), Ca3Bi2 (hP5 --> mC20 --> aP5) and CaBi (tI2 --> tI8), as well as a new phase (Ca3Bi) with a cF4 structure. All the newly predicted structures can be both dynamically and thermodynamically stable with increasing pressure. The superconductive properties of cF4-CaBi3, tI2-CaBi and cF4-Ca3Bi were studied and the superconducting critical temperature Tc can be as high as 5.16, 2.27 and 5.25 K, respectively. Different superconductivity behaviors with pressure increasing have been observed by further investigations.

  16. Entropy stable high order discontinuous Galerkin methods for ideal compressible MHD on structured meshes

    Science.gov (United States)

    Liu, Yong; Shu, Chi-Wang; Zhang, Mengping

    2018-02-01

    We present a discontinuous Galerkin (DG) scheme with suitable quadrature rules [15] for ideal compressible magnetohydrodynamic (MHD) equations on structural meshes. The semi-discrete scheme is analyzed to be entropy stable by using the symmetrizable version of the equations as introduced by Godunov [32], the entropy stable DG framework with suitable quadrature rules [15], the entropy conservative flux in [14] inside each cell and the entropy dissipative approximate Godunov type numerical flux at cell interfaces to make the scheme entropy stable. The main difficulty in the generalization of the results in [15] is the appearance of the non-conservative "source terms" added in the modified MHD model introduced by Godunov [32], which do not exist in the general hyperbolic system studied in [15]. Special care must be taken to discretize these "source terms" adequately so that the resulting DG scheme satisfies entropy stability. Total variation diminishing / bounded (TVD/TVB) limiters and bound-preserving limiters are applied to control spurious oscillations. We demonstrate the accuracy and robustness of this new scheme on standard MHD examples.

  17. Use of systematics in the interpretation of nuclear structure far from the beta-stable region

    International Nuclear Information System (INIS)

    Wood, J.L.

    1979-01-01

    The use of systematics in the interpretation of nuclear structure far from the beta-stable region is discussed. In particular, a set of rules for the use of systematics is presented together with some experimental criteria that need to be fulfilled for radioactive decay scheme studies in order that all states up to a given spin-parity and energy are located. Illustrative examples are taken from the region 180 < A < 210, with particular emphasis on the odd-mass Au and Hg nuclei. 6 figures

  18. Stable isotopes provide insight into population structure and segregation in eastern North Atlantic sperm whales

    DEFF Research Database (Denmark)

    Borrell, Asunción; Velásquez Vacca, Adriana; Pinela, Ana M.

    2013-01-01

    highly mobile, shows indication of structuring in the eastern North Atlantic, an ocean basin in which a single population is believed to occur. To do so, we examined stable isotope values in sequential growth layer groups of teeth from individuals sampled in Denmark and NW Spain. In each layer we...... measured oxygen-isotope ratios (delta O-18) in the inorganic component (hydroxyapatite), and nitrogen and carbon isotope ratios (delta N-15: delta C-13) in the organic component (primarily collagenous). We found significant differences between Denmark and NW Spain in delta N-15 and delta O-18 values...

  19. Structure-Guided Redesign Increases the Propensity of HIV Env To Generate Highly Stable Soluble Trimers.

    Science.gov (United States)

    Guenaga, Javier; Dubrovskaya, Viktoriya; de Val, Natalia; Sharma, Shailendra K; Carrette, Barbara; Ward, Andrew B; Wyatt, Richard T

    2015-12-30

    Due to high viral diversity, an effective HIV-1 vaccine will likely require Envs derived from multiple subtypes to generate broadly neutralizing antibodies (bNAbs). Soluble Env mimics, like the native flexibly linked (NFL) and SOSIP trimers, derived from the subtype A BG505 Env, form homogeneous, stable native-like trimers. However, other Env sequences, such as JRFL and 16055 from subtypes B and C, do so to a lesser degree. The high-resolution BG505 SOSIP crystal structures permit the identification and redesign of Env elements involved in trimer stability. Here, we identified structure trimer-derived (TD) residues that increased the propensity of the subtype B JRFL and subtype C 16055 Env sequences to form well-ordered, homogenous, and highly stable soluble trimers. The generation of these spike mimics no longer required antibody-based selection, positive or negative. Using the redesigned subtype B and C trimer representatives as respective foundations, we further stabilized the NFL TD trimers by engineering an intraprotomer disulfide linkage in the prebridging sheet, I201C-A433C (CC), that locks the gp120 in the receptor nontriggered state. We demonstrated that this disulfide pair prevented CD4 induced-conformational rearrangements in NFL trimers derived from the prototypic subtype A, B, and C representatives. Coupling the TD-based design with the engineered disulfide linkage, CC, increased the propensity of Env to form soluble highly stable spike mimics that are resistant to CD4-induced changes. These advances will allow testing of the hypothesis that such stabilized immunogens will more efficiently elicit neutralizing antibodies in small-animal models and primates. HIV-1 displays unprecedented global diversity circulating in the human population. Since the envelope glycoprotein (Env) is the target of neutralizing antibodies, Env-based vaccine candidates that address such diversity are needed. Soluble well-ordered Env mimics, typified by NFL and SOSIP trimers

  20. Eysenck Personality Inventory Item Factor Structure.

    Science.gov (United States)

    Comrey, Andrew L.; And Others

    1988-01-01

    Three methods were used to test the factor structure of the Eysenck Personality Inventory administered to 583 Australians. The preferred method was to extract factors by the minimum residual method, use the Tandem Criteria Method, and then rotate that number of factors by the Tandem Criteria I method. (SLD)

  1. Ultra-Stable Zero-CTE HoneySiC and H2CMN Mirror Support Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA MSFC, GSFC and JPL are interested in Ultra-Stable Mirror Support Structures for Exoplanet Missions. Telescopes with Apertures of 4-meters or larger and using an...

  2. Ultra-Stable Zero-CTE HoneySiC and H2CMN Mirror Support Structures, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA MSFC, GSFC and JPL are interested in Ultra-Stable Mirror Support Structures for Exoplanet Missions. Telescopes with Apertures of 4-meters or larger and using an...

  3. Morphology, molecular structure, and stable carbon isotopic composition of black carbon (BC) in urban topsoils.

    Science.gov (United States)

    Zong, Yutong; Xiao, Qing; Lu, Shenggao

    2018-02-01

    Urban soils contain significant amounts of black carbon (BC) from biomass and fossil fuel combustion and regard to be a pool of BC. BC in urban soils has multiple effects on environmental processes in urban system, such as global climate change, air quality, and public health. Urban topsoil samples (0-10 cm) were collected from Anshan, Liaoning Province, northeast China, which is one of the most important old steel industrial bases in China. The BC in urban topsoils was extracted using the density method. Their chemical composition, morphology, molecular structure, and stable carbon isotopic composition were examined using elemental analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and stable carbon isotope (δ 13 C). Elemental analysis shows that carbon content in the BC of studied soils ranged from 64.5 to 78.4%, with the average more than 70%. The O/C atomic ratio of BC is on average 0.18. The BC particle displays different morphology, including porous spherical, irregular porous fragmentary, and blocky shapes. The porous spherical BC particles has atomic molar O/C ratio determined by SEM-EDS ranging from 0.04 to 0.37. XRD indicates that BC exists in mainly combining with mineral phases hematite (Fe 2 O 3 ), kaolinite (Al 2 Si 2 O 5 (OH) 4 ), quartz (SiO 2 ), and calcite (CaCO 3 ). The FTIR spectra of BC particles show major bands at approximately 3400 cm -1 (O-H), 2920 cm -1 (C = H), 1600 cm -1 (C = C), 1230 cm -1 (C = O), and 1070 cm -1 (C = O). The stable carbon isotope (δ 13 C) of BC ranges from -24.48 to -23.18‰ with the average of -23.79 ± 0.39‰. The concentration of BC in the industrial area is significantly (p fuel combustion. Results indicated that a combination of atomic O/C ratio, porous structure, and stable carbon isotopic (δ 13 C) of BC could reflect effectively the origin of BC

  4. Factors influencing stable isotopes and growth of algae in oil sands aquatic reclamation.

    Science.gov (United States)

    Boutsivongsakd, Monique; Farwell, Andrea J; Chen, Hao; Dixon, D George

    2015-01-01

    Previous studies reported (15)N enrichment of biota in reclamation wetlands that contain oil sands processed material (e.g., processed water and tailings); however, there is little information on the factors controlling (15)N enrichment in these systems. In this microcosm study, the aim was to examine stable C and N isotopes and growth (chlorophyll a [chl a] and dry weight) of algae as a function of exposure to different sources and concentrations of water-soluble fractions (WSF) derived from tailings. Two sources of tailings including mature fine tailings (MFT) and consolidated tailings (CT) and peat-mineral overburden were utilized to generate separate WSF that differed in water quality. In general, there was (15)N enrichment of filamentous algae along the increasing gradient of WSF/nutrient concentrations in both CT and peat microcosms, and among the different sources, algae were more (15)N enriched in CT WSF than in peat WSF. Growth of filamentous algae was inhibited at higher WSF concentrations, possibly due to reduced light availability at elevated levels of fine clay particles in MFT microcosms and colored dissolved organic carbon (DOC) in peat microcosms. Filamentous algae displayed lower biomass and (15)N depletion in 100% peat WSF. This study indicated that both the quality (source) and quantity of WSF affected algal growth and directly and/or indirectly influenced δ(15)N of algae. The distinct (15)N enrichment of primary producers derived from tailings suggest that stable N isotopes might be useful to trace exposure to oil sands processed material in biota that utilize these resources in reclaimed systems constructed with tailings or natural systems that receive tailings dyke seepage.

  5. Effect of surface texture and structure on the development of stable fluvial armors

    Science.gov (United States)

    Bertin, Stephane; Friedrich, Heide

    2018-04-01

    Stable fluvial armors are found in river systems under conditions of partial sediment transport and limited sediment supply, a common occurrence in nature. Stable armoring is also readily recreated in experimental flumes. Initially, this bed stabilizing phenomenon was examined for different flow discharges and solely related to surface coarsening and bedload transport reduction. The models developed suggest a specific armor composition (i.e., texture) dependent on the parent bed material and formative discharge. Following developments in topographic remote sensing, recent research suggests that armor structure is an important control on bed stability and roughness. In this paper, replicated flume runs during which digital elevation models (DEMs) were collected from both exposed and flooded gravel beds are used to interpret armoring manifestations and to assess their replicability. A range of methodologies was used for the analysis, providing information on (i) surface grain size and orientation, (ii) bed-elevation distributions, (iii) the spatial coherence of the elevations at the grain-scale, (iv) surface slope and aspect, (v) grain imbrication and (vi) the spatial variability in DEM properties. The bed-surface topography was found to be more responsive than bed-material size to changes in flow strength. Our experimental results also provide convincing evidence that gravel-beds' response to water-work during parallel degradation is unique (i.e., replicable) given the formative parameters. Based on this finding, relationships between the armors' properties and formative parameters are proposed, and are supported by adding extensive data from previous research.

  6. Determination of Trophic Structure in Selected Freshwater Ecosystems by using Stable Isotope Analysis.

    Science.gov (United States)

    Zainordin, 'Amila Faqhira; Ab Hamid, Suhaila

    2017-07-01

    Stable isotope analysis has been used extensively to establish trophic relationships in many ecosystems. Present study utilised stable isotope signatures of carbon and nitrogen to identify trophic structure of aquatic food web in river and rice field ecosystems in Perak, northern peninsular Malaysia. The mean δ 13 C values of all producers ranged from -35.29 ± 0.21 to -26.00 ± 0.050‰. The greatest δ 15 N values noted was in zenarchopterid fish with 9.68 ± 0.020‰. The δ 15 N values of aquatic insects ranged between 2.59 ± 0.107 in Elmidae (Coleoptera) and 8.11 ± 0.022‰ in Nepidae (Hemiptera). Correspondingly, with all the δ 13 C and δ 15 N values recorded, it can be deduced that there are four trophic levels existed in the freshwater ecosystems which started with the producer (plants), followed by primary consumer (aquatic insects and non-predatory fish), secondary consumer (invertebrate predators) and lastly tertiary consumer (vertebrate predators).

  7. The Factor Structure in Equity Options

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Fournier, Mathieu; Jacobs, Kris

    Equity options display a strong factor structure. The first principal components of the equity volatility levels, skews, and term structures explain a substantial fraction of the cross-sectional variation. Furthermore, these principal components are highly correlated with the S&P500 index option ...

  8. The Factor Structure in Equity Options

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Fournier, Mathieu; Jacobs, Kris

    2018-01-01

    Equity options display a strong factor structure. The first principal components of the equity volatility levels, skews, and term structures explain a substantial fraction of the crosssectional variation. Furthermore, these principal components are highly correlated with the S&P 500 index option ...

  9. Factor Analytic Structure of the MCMI Items.

    Science.gov (United States)

    Choca, James; And Others

    The factor analytic studies that have been done with the Millon Clinical Multiaxial Inventory (MCMI), a 175-item paper-and-pencil test designed to evaluate symptomology in psychiatric patients, have been problematic in that the test's high inter-scale correlation could lead to an artificially robust factor structure. The present investigation…

  10. NAC transcription factors: structurally distinct, functionally diverse

    DEFF Research Database (Denmark)

    Olsen, Addie Nina; Ernst, Heidi A; Leggio, Leila Lo

    2005-01-01

    level and localization, and to the first indications of NAC participation in transcription factor networks. The recent determination of the DNA and protein binding NAC domain structure offers insight into the molecular functions of the protein family. Research into NAC transcription factors has...

  11. Stable anilinyl radicals coordinated to nickel: X-ray crystal structure and characterization.

    Science.gov (United States)

    Kochem, Amélie; Gellon, Gisèle; Leconte, Nicolas; Baptiste, Benoit; Philouze, Christian; Jarjayes, Olivier; Orio, Maylis; Thomas, Fabrice

    2013-12-02

    Two anilinosalen and a mixed phenol-anilinosalen ligands involving sterically hindered anilines moieties were synthesized. Their nickel(II) complexes 1, 2, and 3 were prepared and characterized. They could be readily one-electron oxidized (E(1/2)=-0.30, -0.26 and 0.10 V vs. Fc(+)/Fc, respectively) into anilinyl radicals species [1](+), [2](+), and [3](+), respectively. The radical complexes are extremely stable and were isolated as single crystals. X-ray crystallographic structures reveal that the changes in bond length resulting from oxidation do not exceed 0.02 Å within the ligand framework in the symmetrical [1](+) and [2](+). No quinoid bond pattern was present. In contrast, larger structural rearrangements were evidenced for the unsymmetrical [3](+), with shortening of one C(ortho)-C(meta) bond. Radical species [1](+) and [2](+) exhibit a strong absorption band at around 6000 cm(-1) (class III mixed valence compounds). This band is significantly less intense than [3](+), consistent with a rather localized anilinyl radical character, and thus a classification of this species as class II mixed-valence compound. Magnetic and electronic properties, as well as structural parameters, have been computed by DFT methods. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Highly active and stable oxaloacetate decarboxylase Na⁺ pump complex for structural analysis.

    Science.gov (United States)

    Inoue, Michio; Li, Xiaodan

    2015-11-01

    The oxaloacetate decarboxylase primary Na(+) pump (Oad) produces energy for the surviving of some pathogenic bacteria under anaerobic conditions. Oad composes of three subunits: Oad-α, a biotinylated soluble subunit and catalyzes the decarboxylation of oxaloacetate; Oad-β, a transmembrane subunit and functions as a Na(+) pump; and Oad-γ, a single transmembrane α-helical anchor subunit and assembles Oad-α/β/γ complex. The molecular mechanism of Oad complex coupling the exothermic decarboxylation to generate the Na(+) electrochemical gradient remains unsolved. Our biophysical and biochemical studies suggested that the stoichiometry of Oad complex from Vibrio cholerae composed of α, β, γ in 4:2:2 stoichiometry not that of 4:4:4. The high-resolution structure determination of the Oad complex would reveal the energetic transformation mechanism from the catalytical soluble α subunit to membrane β subunit. Sufficient amount stable, conformational homogenous and active Oad complex with the right stoichiometry is the prerequisite for structural analysis. Here we report an easy and reproducible protocol to obtain high quantity and quality Oad complex protein for structural analysis. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Stable feature selection for clinical prediction: exploiting ICD tree structure using Tree-Lasso.

    Science.gov (United States)

    Kamkar, Iman; Gupta, Sunil Kumar; Phung, Dinh; Venkatesh, Svetha

    2015-02-01

    Modern healthcare is getting reshaped by growing Electronic Medical Records (EMR). Recently, these records have been shown of great value towards building clinical prediction models. In EMR data, patients' diseases and hospital interventions are captured through a set of diagnoses and procedures codes. These codes are usually represented in a tree form (e.g. ICD-10 tree) and the codes within a tree branch may be highly correlated. These codes can be used as features to build a prediction model and an appropriate feature selection can inform a clinician about important risk factors for a disease. Traditional feature selection methods (e.g. Information Gain, T-test, etc.) consider each variable independently and usually end up having a long feature list. Recently, Lasso and related l1-penalty based feature selection methods have become popular due to their joint feature selection property. However, Lasso is known to have problems of selecting one feature of many correlated features randomly. This hinders the clinicians to arrive at a stable feature set, which is crucial for clinical decision making process. In this paper, we solve this problem by using a recently proposed Tree-Lasso model. Since, the stability behavior of Tree-Lasso is not well understood, we study the stability behavior of Tree-Lasso and compare it with other feature selection methods. Using a synthetic and two real-world datasets (Cancer and Acute Myocardial Infarction), we show that Tree-Lasso based feature selection is significantly more stable than Lasso and comparable to other methods e.g. Information Gain, ReliefF and T-test. We further show that, using different types of classifiers such as logistic regression, naive Bayes, support vector machines, decision trees and Random Forest, the classification performance of Tree-Lasso is comparable to Lasso and better than other methods. Our result has implications in identifying stable risk factors for many healthcare problems and therefore can

  14. A hypoplastic constitutive model for clays with meta-stable structure

    Czech Academy of Sciences Publication Activity Database

    Mašín, David

    2007-01-01

    Roč. 44, č. 3 (2007), s. 363-375 ISSN 0008-3674 R&D Projects: GA AV ČR(CZ) IAA200710605 Institutional research plan: CEZ:AV0Z20710524 Keywords : constitutive relations * hypoplasticity * clays * structure of soils Subject RIV: JM - Building Engineering Impact factor: 0.542, year: 2007

  15. Structurally stable design of output regulation for a class of nonlinear systems

    Czech Academy of Sciences Publication Activity Database

    Villanueva-Novelo, C.; Čelikovský, Sergej; Castillo-Toledo, B.

    2001-01-01

    Roč. 37, č. 5 (2001), s. 517-561 ISSN 0023-5954 R&D Projects: GA ČR GA102/99/1368 Institutional research plan: AV0Z1075907 Keywords : nonlinear systems * structural stability * output regulation Subject RIV: BC - Control Systems Theory Impact factor: 0.316, year: 2001

  16. Aedes aegypti has spatially structured and seasonally stable populations in Yogyakarta, Indonesia.

    Science.gov (United States)

    Rašić, Gordana; Endersby-Harshman, Nancy; Tantowijoyo, Warsito; Goundar, Anjali; White, Vanessa; Yang, Qiong; Filipović, Igor; Johnson, Petrina; Hoffmann, Ary A; Arguni, Eggi

    2015-12-01

    Dengue fever, the most prevalent global arboviral disease, represents an important public health problem in Indonesia. Control of dengue relies on the control of its main vector, the mosquito Aedes aegypti, yet nothing is known about the population history and genetic structure of this insect in Indonesia. Our aim was to assess the spatio-temporal population genetic structure of Ae. aegypti in Yogyakarta, a densely populated region on Java with common dengue outbreaks. We used multiple marker systems (microsatellites, nuclear and mitochondrial genome-wide single nucleotide polymorphisms generated via Restriction-site Associated DNA sequencing) to analyze 979 Ae. aegypti individuals collected from the Yogyakarta city and the surrounding hamlets during the wet season in 2011 and the following dry season in 2012. We employed individual- and group-based approaches for inferring genetic structure. We found that Ae. aegypti in Yogyakarta has spatially structured and seasonally stable populations. The spatial structuring was significant for the nuclear and mitochondrial markers, while the temporal structuring was non-significant. Nuclear markers identified three main genetic clusters, showing that hamlets have greater genetic isolation from each other and from the inner city sites. However, one hamlet experienced unrestricted mosquito interbreeding with the inner city, forming a single genetic cluster. Genetic distance was poorly correlated with the spatial distance among mosquito samples, suggesting stronger influence of human-assisted gene flow than active mosquito movement on spatial genetic structure. A star-shaped mitochondrial haplotype network and a significant R(2) test statistic (R(2) = 0.0187, P = 0.001) support the hypothesis that Ae. aegypti in Yogyakarta originated from a small or homogeneous source and has undergone a relatively recent demographic expansion. We report the first insights into the spatio-temporal genetic structure and the underlying

  17. A Fundamental Approach to Developing Aluminium based Bulk Amorphous Alloys based on Stable Liquid Metal Structures and Electronic Equilibrium - 154041

    Science.gov (United States)

    2017-03-28

    AFRL-AFOSR-JP-TR-2017-0027 A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal Structures and...to 16 Dec 2016 4.  TITLE AND SUBTITLE A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal...Air Force Research Laboratory for accurately predicting compositions of new amorphous alloys specifically based on aluminium with properties superior

  18. Predictive factors for functional outcome and failure in angular stable osteosynthesis of the proximal humerus.

    LENUS (Irish Health Repository)

    Hardeman, Francois

    2012-02-01

    Angular stable osteosynthesis has become the gold standard in the operative treatment of proximal humeral fractures. The aim of this article is to determine the indications for osteosynthesis versus primary arthroplasty based on clinical and radiological parameters.

  19. The Factor Structure in Equity Options

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Fournier, Mathieu; Jacobs, Kris

    Principal component analysis of equity options on Dow-Jones firms reveals a strong factor structure. The first principal component explains 77% of the variation in the equity volatility level, 77% of the variation in the equity option skew, and 60% of the implied volatility term structure across...... equities. Furthermore, the first principal component has a 92% correlation with S&P500 index option volatility, a 64% correlation with the index option skew, and a 80% correlation with the index option term structure. We develop an equity option valuation model that captures this factor structure...... on a large set of index and equity option data on which the model provides a good fit. The equity option data support the cross-sectional implications of the estimated model....

  20. On R factors for dynamic structure crystallography

    DEFF Research Database (Denmark)

    Coppens, Philip; Kaminski, Radoslaw; Schmøkel, Mette Stokkebro

    2010-01-01

    In studies of dynamic changes in crystals in which induced metastable species may have lifetimes of microseconds or less, refinements are most sensitive if based on the changes induced in the measured intensities. Agreement factors appropriate for such refinements, based on the ratios of the inte...... of the intensities before and after the external perturbation is applied, are discussed and compared with R factors commonly applied in static structure crystallography....

  1. Structure of stable binary neutron star merger remnants: Role of initial spin

    Science.gov (United States)

    Kastaun, W.; Ciolfi, R.; Endrizzi, A.; Giacomazzo, B.

    2017-08-01

    We present general relativistic numerical simulations of binary neutron star (BNS) mergers with different initial spin configurations. We focus on models with stars of mass 1.4 M⊙ each, which employ the equation of state (EOS) by Shen, Horowitz, and Teige, and which result in stable NSs as merger remnants. For comparison, we consider two irrotational equal mass (M =1.35 M⊙) and unequal mass (M =1.29 , 1.42 M⊙ ) BNS models using the APR4 EOS, which result in a supramassive merger remnant. We present visualizations of the fluid flow and temperature distribution and find a strong impact of the spin on vortex structure and nonaxisymmetric deformation. We compute the radial mass distribution and the rotation profile in the equatorial plane using recently developed measures independent of spatial gauge, revealing slowly rotating cores that can be well approximated by the cores of spherical stars. We also study the influence of the spin on the inspiral phase and the gravitational wave (GW) signal. Using a newly developed analysis method, we further show that gravitational waveforms from BNS mergers can exhibit one or more phase jumps after merger, which occur together with minima of the strain amplitude. We provide a natural explanation in terms of the remnant's quadrupole moment, and show that cancellation effects due to phase jumps can have a strong impact on the GW power spectrum. Finally, we discuss the impact of the spin on the amount of ejected matter.

  2. Exploration of stable compounds, crystal structures, and superconductivity in the Be-H system

    Directory of Open Access Journals (Sweden)

    Shuyin Yu

    2014-10-01

    Full Text Available Using first-principles variable-composition evolutionary methodology, we explored the high-pressure structures of beryllium hydrides between 0 and 400 GPa. We found that BeH2 remains the only stable compound in this pressure range. The pressure-induced transformations are predicted as I b a m → P 3 ̄ m 1 → R 3 ̄ m → C m c m → P 4 / n m m , which occur at 24, 139, 204 and 349 GPa, respectively. P 3 ̄ m 1 and R 3 ̄ m structures are layered polytypes based on close packings of H atoms with Be atoms filling all octahedral voids in alternating layers. Cmcm and P4/nmm contain two-dimensional triangular networks with each layer forming a kinked slab in the ab-plane. P 3 ̄ m 1 and R 3 ̄ m are semiconductors while Cmcm and P4/nmm are metallic. We have explored superconductivity of both metal phases, and found large electron-phonon coupling parameters of λ = 0.63 for Cmcm with a Tc of 32.1-44.1 K at 250 GPa and λ = 0.65 for P4/nmm with a Tc of 46.1-62.4 K at 400 GPa. The dependence of Tc on pressure indicates that Tc initially increases to a maximum of 45.1 K for Cmcm at 275 GPa and 97.0 K for P4/nmm at 365 GPa, and then decreases with increasing pressure for both phases.

  3. Structure of stable binary neutron star merger remnants: A case study

    Science.gov (United States)

    Kastaun, W.; Ciolfi, R.; Giacomazzo, B.

    2016-08-01

    In this work, we study the merger of two neutron stars with a gravitational mass of 1.4 M⊙ each, employing the Shen-Horowitz-Teige equation of state. This equation of state is a corner case, allowing the formation of a stable neutron star with the given total baryonic mass of 3.03 M⊙. We investigate in unprecedented detail the structure of the remnant, in particular the mass distribution, the thermal structure, and the rotation profile. We also compute fluid trajectories both inside the remnant and those relevant for the formation of the disk. We find a peanut-shaped fluid flow inside the remnant following a strong m =2 perturbation. Moreover, the flow is locally compressive, causing the appearance of dynamic hot spots. Further, we introduce new diagnostic measures that are easy to implement in numeric simulations and that allow one to quantify mass and compactness of merger remnants in a well-defined way. As in previous studies of supra- and hypermassive stars, we find a remnant with a slowly rotating core and an outer envelope rotating at nearly Keplerian velocity. We compute a Tolman-Oppenheimer-Volkoff star model which agrees well with that of the remnant in the core, while the latter possesses extensive outer layers rotating close to Kepler velocity. Finally, we extract the gravitational wave signal and discuss the detectability with modern observatories. This study has implications for the interpretation of gravitational wave detections from the postmerger phase and is relevant for short gamma-ray burst models.

  4. Structure factors and phonon dispersion in liquid

    Indian Academy of Sciences (India)

    2Electronics Department, Narmada College of Science and Commerce, Bharuch 392 011,. India. E-mail: apratapmsu@yahoo.com. Abstract. The phonon spectra for .... Structure factors and phonon dispersion in liquid Li0.61Na0.39 alloy. [5] U Balucani and M Zoppi, Dynamics of the liquid state (Clarendon, Oxford, 1994).

  5. On stable exponential cosmological solutions with non-static volume factor in the Einstein-Gauss-Bonnet model

    International Nuclear Information System (INIS)

    Ivashchuk, V D; Ernazarov, K K

    2017-01-01

    A ( n + 1)-dimensional gravitational model with cosmological constant and Gauss-Bonnet term is studied. The ansatz with diagonal cosmological metrics is adopted and solutions with exponential dependence of scale factors: a i ∼ exp ( v i t ), i = 1, …, n , are considered. The stability analysis of the solutions with non-static volume factor is presented. We show that the solutions with v 1 = v 2 = v 3 = H > 0 and small enough variation of the effective gravitational constant G are stable if certain restriction on ( v i ) is obeyed. New examples of stable exponential solutions with zero variation of G in dimensions D = 1 + m + 2 with m > 2 are presented. (paper)

  6. Highly transparent, stable, and superhydrophobic coatings based on gradient structure design and fast regeneration from physical damage

    Science.gov (United States)

    Chen, Zao; Liu, Xiaojiang; Wang, Yan; Li, Jun; Guan, Zisheng

    2015-12-01

    Optical transparency, mechanical flexibility, and fast regeneration are important factors to expand the application of superhydrophobic surfaces. Herein, we fabricated highly transparent, stable, and superhydrophobic coatings through a novel gradient structure design by versatile dip-coating of silica colloid particles (SCPs) and diethoxydimethysiliane cross-linked silica nanoparticles (DDS-SNPs) on polyethylene terephthalate (PET) film and glass, followed by the modification of octadecyltrichlorosiliane (OTCS). When the DDS concentration reached 5 wt%, the modified SCPs/DDS-SNPs coating exhibited a water contact angle (WCA) of 153° and a sliding angle (SA) superhydrophobic coating on PET film and glass was increased by 2.7% and 1% in the visible wavelength, respectively. This superhydrophobic coating also showed good robustness and stability against water dropping impact, ultrasonic damage, and acid solution. Moreover, the superhydrophobic PET film after physical damage can quickly regain the superhydrophobicity by one-step spray regenerative solution of dodecyltrichlorosilane (DTCS) modified silica nanoparticles at room temperature. The demonstrated method for the preparation and regeneration of superhydrophobic coating is available for different substrates and large-scale production at room temperature.

  7. The influence factor analyses of non-stable combustion in the ignition process of gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, Jian-ping; Zhang, Shi-cheng; Jie, Tao; Cao, Feng; Chen, Xu-si; Li, Hang; Liu, Yong-sun [ShangHai Marine diesel Engine Research Institute, Shanghai (China)

    2013-07-01

    The pulverized coal gasification technology is large-scale carried out in China for more than 10 years, and more and more coal gasification technology, such as SCGP, GSP, GE, indigenous gasifier, have been widely used in China. Ignition process is non-stable combustion process, which is the key process in the operation of gasifier. In ignition process of pulverized coal gasifier, the average temperature and pressure will increase to high level (about 800 C and 1 MPa) from the normal condition. In this paper, the trial furnace experiment have been carried out to study the non-stable flow and combustion characteristics in gasifier. The variety of the temperature and the shape of the flame with the pressure growing have been analyzed. These results show that the average temperature is increasing gradually at atmosphere pressure, while the high temperature region locates 100 mm away from the head of the ignition burner with a spindly shape. As the pressure goes up, the shapes of the flame shorten apparently, while the distance between the high temperature region and the head of the start-up burner decreases. Thereby, it is possible that the head of the start-up-burner will burning-out by the high temperature flame. Therefore, the pressure will tremendously influence the combustion process in gasifier, where the flame will change shortly and unstably.

  8. Static structure factor of liquid parahydrogen

    International Nuclear Information System (INIS)

    Dawidowski, J.; Bermejo, F.J.; Ristig, M.L.; Faak, B.; Cabrillo, C.; Fernandez-Perea, R.; Kinugawa, K.; Campo, J.

    2004-01-01

    The single-differential neutron-scattering cross section of liquid parahydrogen has been measured at 15.2 K and 2 bars of applied pressure by means of low-energy neutron diffraction. Our experimental conditions enable the direct observation of the peak of the liquid structure factor and therefore largely improve the signal-to-noise ratio with respect to measurements carried out using higher-energy neutron diffraction. This avoids the need of performing corrections of approximate nature to the measured cross section that is dominated by molecular rotational components if measured by conventional neutron diffraction

  9. The factor structure of six salutogenic constructs

    Directory of Open Access Journals (Sweden)

    Marita Breed

    2006-10-01

    Full Text Available The aim of this research was to investigate the factor structure of six salutogenic constructs, namely sense of coherence, hardiness, learned resourcefulness, potency, internal locus of control and self-efficacy. Measurement with a sample of 935 part-time students did not fit the conceptualisation of salutogenesis. A different factor structure for Whites versus Others occurred. For Whites, all six constructs more or less contributed towards the general salutogenic factor and for Others all but learned resourcefulness contributed. For Whites, salutogenesis consisted of two clear dimensions (a global positive orientation; specific behavioural skills and for Others one dimension (an optimistic life view. Confirmatory factor analysis performed on the data for both groups, indicated a weak fit. It was recommended that salutogenesis be further explored within an overall personality theory. Opsomming Die doel van hierdie navorsing was om die faktorstruktuur van ses salutogeniese konstrukte te ondersoek, naamlik sin vir koherensie, gehardheid, aangeleerde vindingrykheid, potensie, interne lokus van beheer en selfgenoegsaamheid. Meting met ‘n steekproef van 935 deeltydse studente het nie ‘n passing getoon met die konseptualisering van salutogenese nie. ‘n Eiesoortige faktorstruktuur vir Wit studente versus Ander studente het voorgekom. Vir Wittes, het al ses die konstrukte meer of minder bygedra tot die algemene salutugeniese faktor en vir Andere het almal behalwe aangeleerde vindingrykheid bygedra. Vir Wittes bestaan salutogenese uit twee duidelike dimensies (‘n globale positiewe lewensorientasie; spesifieke gedrags vaardighede en vir Andere uit een dimensie (‘n optimistiese lewensbeskouing. Bevestigende faktor ontleding uitgevoer op die data van beide groepe, het ‘n swak passing getoon. Daar is aanbeveel dat salutogenese verder ondersoek word binne ‘n oorkoepelende persoonlikheidsteorie.

  10. A chemically stable electrolyte with a novel sandwiched structure for proton-conducting solid oxide fuel cells (SOFCs)

    KAUST Repository

    Bi, Lei

    2013-11-01

    A chemically stable electrolyte structure was developed for proton-conducting SOFCs by using two layers of stable BaZr0.7Pr 0.1Y0.2O3 -δ to sandwich a highly-conductive but unstable BaCe0.8Y0.2O 3 -δ electrolyte layer. The sandwiched electrolyte structure showed good chemical stability in both CO2 and H2O atmosphere, indicating that the BZPY layers effectively protect the inner BCY electrolyte, while the BCY electrolyte alone decomposed completely under the same conditions. Fuel cell prototypes fabricated with the sandwiched electrolyte achieved a relatively high performance of 185 mW cm- 2 at 700 C, with a high electrolyte film conductivity of 4 × 10- 3 S cm- 1 at 600 C. © 2013 Elsevier B.V.

  11. Closed Pore Structured NiCo2O4-Coated Nickel Foams for Stable and Effective Oil/Water Separation.

    Science.gov (United States)

    Li, Yan; Zheng, Xi; Yan, Zhanheng; Tian, Dongliang; Ma, Jianmin; Zhang, Xiaofang; Jiang, Lei

    2017-08-30

    To solve the serious problem caused by oily wastewater pollution, unique interface designs, for example, membranes with superwetting properties such as superhydrophobicity/superoleophilicity and superhydrophilicity/underwater superoleophobicity, provide a good way to achieve oil/water separation. Here, inspired by the liquid storage property of the honeycomb structure, we propose a strategy to fabricate NiCo 2 O 4 -coated nickel foams for stable and efficient oil/water separation. NiCo 2 O 4 with a closed-pore structure was formed by assembling nanoflakes with a micro/nanoscale hierarchical structure. Compared with nickel foam coated by NiCo 2 O 4 with an open-pore structure (NiCo 2 O 4 nanowires), the enclosed nanostructure of NiCo 2 O 4 nanoflakes can firmly hold water for a more stable superhydrophilic/underwater superoleophobic interface. As a consequence, the NiCo 2 O 4 -nanoflake-coated nickel foam has a larger oil breakthrough pressure than the NiCo 2 O 4 -nanowire-coated nickel foam because of a slightly larger oil advancing angle and a lower underwater oil adhesion force, which makes it more stable and efficient for oil/water separation. Moreover, the NiCo 2 O 4 -coated nickel foams have excellent chemical and mechanical stability, and they are reusable for oil-water separation. This work will be beneficial for the design and development of stable underwater superoleophobic self-cleaning materials and related device applications, such as oil/water separation.

  12. Factors Affecting Mercury Stable Isotopic Distribution in Piscivorous Fish of the Laurentian Great Lakes.

    Science.gov (United States)

    Lepak, Ryan F; Janssen, Sarah E; Yin, Runsheng; Krabbenhoft, David P; Ogorek, Jacob M; DeWild, John F; Tate, Michael T; Holsen, Thomas M; Hurley, James P

    2018-03-06

    Identifying the sources of methylmercury (MeHg) and tracing the transformations of mercury (Hg) in the aquatic food web are important components of effective strategies for managing current and legacy Hg sources. In our previous work, we measured stable isotopes of Hg (δ 202 Hg, Δ 199 Hg, and Δ 200 Hg) in the Laurentian Great Lakes and estimated source contributions of Hg to bottom sediment. Here, we identify isotopically distinct Hg signatures for Great Lakes trout ( Salvelinus namaycush) and walleye ( Sander vitreus), driven by both food-web and water-quality characteristics. Fish contain high values for odd-isotope mass independent fractionation (MIF) with averages ranging from 2.50 (western Lake Erie) to 6.18‰ (Lake Superior) in Δ 199 Hg. The large range in odd-MIF reflects variability in the depth of the euphotic zone, where Hg is most likely incorporated into the food web. Even-isotope MIF (Δ 200 Hg), a potential tracer for Hg from precipitation, appears both disconnected from lake sedimentary sources and comparable in fish among the five lakes. We suggest that similar to the open ocean, water-column methylation also occurs in the Great Lakes, possibly transforming recently deposited atmospheric Hg deposition. We conclude that the degree of photochemical processing of Hg is controlled by phytoplankton uptake rather than by dissolved organic carbon quantity among lakes.

  13. Finding the Stable Structures of WxN1-x with an ab-initio High-Throughput Approach

    Science.gov (United States)

    2014-03-13

    properties must be energetically stable against decomposition into other compounds. This stability can only be found after the determination of the...polarized. However, in every structure the self-consistent magnetic moment was negligible, and the final calculations were all done assuming no moment. The...of NaCl) we looked at all 255 combinations. We found 34 unique structures, including NbO itself, CsCl, S3U4, ReO3,[59] cubic perovskite (with formula

  14. The effect of environmental factors on stable isotopic composition of n-alkanes in Mediterranean olive oils

    Science.gov (United States)

    Pedentchouk, Nikolai; Mihailova, Alina; Abbado, Dimitri

    2014-05-01

    Traceability of the geographic origin of olive oils is an important issue from both commercial and health perspectives. This study evaluates the impact of environmental factors on stable C and H isotope compositions of n-alkanes in extra virgin olive oils from Croatia, France, Greece, Italy, Morocco, Portugal, Slovenia, and Spain. The data are used to investigate the applicability of stable isotope methodology for olive oil regional classification in the Mediterranean region. Analysis of stable C isotope composition of n-C29 alkane showed that extra virgin olive oils from Portugal and Spain have the most positive n-C29 alkane delta13C values. Conversely, olive oils from Slovenia, northern and central Italy are characterized by the most negative values. Overall, the n-C29 alkane delta13C values show a positive correlation with the mean air temperature during August-December and a negative correlation with the mean relative humidity during these months. Analysis of stable H isotope composition of n-C29 alkane revealed that the deltaD values are the most positive in olive oils from Greece and Morocco and the most negative in oils from northern Italy. The deltaD values of oils show significant correlation with all the analyses geographical parameters: the mean air temperature and relative humidity during August-December, the total amount of rainfall (the same months) and the annual deltaD values of precipitation. As predictor variables in the Categorical Data Analysis, the n-C29 alkane deltaD values show the most significant discriminative power, followed by the n-C29 alkane delta13C values. Overall, 93.4% of olive oil samples have been classified correctly into one of the production regions. Our findings suggest that an integrated analysis of C and H isotope compositions of n-alkanes extracted from extra virgin olive oil could become a useful tool for geographical provenancing of this highly popular food commodity.

  15. Dynamic reorganization of chromatin structure and selective DNA demethylation prior to stable enhancer complex formation during differentiation of primary hematopoietic cells in vitro.

    Science.gov (United States)

    Tagoh, Hiromi; Melnik, Svitlana; Lefevre, Pascal; Chong, Suyinn; Riggs, Arthur D; Bonifer, Constanze

    2004-04-15

    In order to gain insights in the true molecular mechanisms involved in cell fate decisions, it is important to study the molecular details of gene activation where such decisions occur, which is at the level of the chromatin structure of individual genes. In the study presented here we addressed this issue and examined the dynamic development of an active chromatin structure at the chicken lysozyme locus during the differentiation of primary myeloid cells from transgenic mouse bone marrow. Using in vivo footprinting we found that stable enhancer complex assembly and high-level gene expression are late events in cell differentiation. However, even before the onset of gene expression and stable transcription factor binding, specific chromatin alterations are observed. This includes changes in DNA topology and the selective demethylation of CpG dinucleotides located in the cores of critical transcription factor binding sites, but not in flanking DNA. These results firmly support the idea that epigenetic programs guiding blood cell differentiation are engraved into the chromatin of lineage-specific genes and that such chromatin changes are implemented before cell lineage specification.

  16. Dynamic structure factor of vibrating fractals.

    Science.gov (United States)

    Reuveni, Shlomi; Klafter, Joseph; Granek, Rony

    2012-02-10

    Motivated by novel experimental work and the lack of an adequate theory, we study the dynamic structure factor S(k,t) of large vibrating fractal networks at large wave numbers k. We show that the decay of S(k,t) is dominated by the spatially averaged mean square displacement of a network node, which evolves subdiffusively in time, ((u[over →](i)(t)-u[over →](i)(0))(2))∼t(ν), where ν depends on the spectral dimension d(s) and fractal dimension d(f). As a result, S(k,t) decays as a stretched exponential S(k,t)≈S(k)e(-(Γ(k)t)(ν)) with Γ(k)∼k(2/ν). Applications to a variety of fractal-like systems are elucidated.

  17. Risk factors for re-fracture in children with diaphyseal fracture of the forearm treated with elastic stable intramedullary nailing.

    Science.gov (United States)

    Rousset, Marie; Mansour, Mounira; Samba, Antoine; Pereira, Bruno; Canavese, Federico

    2016-02-01

    A retrospective study aims to investigate predisposing factors leading to re-fracture in patients with nails still in place and to identify potential correlations between nail size-to-medullary canal diameter ratio and re-fracture, working to the hypothesis that a higher ratio correlates with a higher risk of re-fracture. Rates of re-fracture with nail still in place after forearm elastic stable intramedullary nailing are higher in younger pediatric patients. Re-fractures occurred at a mean age of 6.7 years (range 5-8.7). While the role of body frame and bone medullary diameter remains unclear, there are grounds for adjusting treatment strategy for age, weight and bone medullary diameter to achieve effective outcome. History of previous forearm fracture and open treatment may also be further risk factors.

  18. Sonochemical synthesis, structure and magnetic properties of air-stable Fe3O4/Au nanoparticles

    International Nuclear Information System (INIS)

    Wu Wei; He Quanguo; Chen Hong; Tang Jianxin; Nie Libo

    2007-01-01

    Air-stable nanoparticles of Fe 3 O 4 /Au were prepared via sonolysis of a solution mixture of hydrogen tetrachloroaureate(III) trihydrate (HAuCl 4 ) and (3-aminopropyl)triethoxysilane (APTES)-coated Fe 3 O 4 nanoparticles with further drop-addition of sodium citrate. The Fe 3 O 4 /Au nanoparticles were characterized by x-ray powder diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS) and superconducting quantum interference device (SQUID) magnetometry. Nanoparticles of Fe 3 O 4 /Au obtained under appropriate conditions possess a very high saturation magnetization of about 63 emu g -1 and their average diameter is about 30 nm

  19. Mechanically stable tuning fork sensor with high quality factor for the atomic force microscope.

    Science.gov (United States)

    Kim, Kwangyoon; Park, Jun-Young; Kim, K B; Lee, Naesung; Seo, Yongho

    2014-01-01

    A quartz tuning fork was used instead of cantilever as a force sensor for the atomic force microscope. A tungsten tip was made by electrochemical etching from a wire of 50 µm diameter. In order to have mechanical stability of the tuning fork, it was attached on an alumina plate. The tungsten tip was attached on the inside end of a prong of a tuning fork. The phase shift was used as a feedback signal to control the distance between the tip and sample, and the amplitude was kept constant using a lock-in amplifier and a homemade automatic gain controller. Due to the mechanical stability, the sensor shows a high quality factor (∼10(3)), and the image quality obtained with this sensor was equivalent to that of the cantilever-based AFM. © 2014 Wiley Periodicals, Inc.

  20. Soil structure stability and distribution of carbon in water-stable aggregates in different tilled and fertilized Haplic Luvisol

    Directory of Open Access Journals (Sweden)

    Vladimír Šimanský

    2012-01-01

    Full Text Available The influence of tillage and fertilization on soil structure stability and the distribution of carbon in water-stable aggregates of loamy Haplic Luvisol were studied. Soil samples from the locality of Dolná Malanta (experimental station of SUA Nitra were collected (in 2007–2009 from a depth of 0–0.2 m in two tillage variants: (1. conventional tillage, 2. minimal tillage and three treatments of fertilization: (1. without fertilization, 2. crop residues and NPK fertilizers, 3. NPK fertilizers. The minimal tillage system has a positive effect on both the aggregation processes and sequestration of carbon in size fractions of water-stable aggregates, as well as ploughing of crop residues together with NPK fertilizers. On the other hand, application of only NPK fertilizers had a negative effect on SOM content. Under the minimal tillage system and in treatment with crop residues together with NPK fertilizers, what has been observed is a statistically significant increase in the total organic carbon contents by increasing size fractions of water-stable aggregates. Organic carbon did not influence the aggregation processes with dependence on tillage systems. Under conventional tillage as well as in treatment with ploughing crop residues with NPK fertilizers, a very important effect on aggregation had bivalent cations Ca2+ and Mg2+.

  1. Dietary shift after 3600 cal yr BP and its influencing factors in northwestern China: Evidence from stable isotopes

    Science.gov (United States)

    Ma, Minmin; Dong, Guanghui; Jia, Xin; Wang, Hui; Cui, Yifu; Chen, Fahu

    2017-04-01

    :Human diets rely on natural resource availability and can reflect social and cultural values. When environments, societies, and cultures change, diets may also shift. This study traced the extent of dietary change and the factors influencing such change. Through stable carbon and nitrogen isotopic analysis of late Neolithic and early Bronze Age human and animal bone collagen, we found that significant shifts in human diets were closely associated with intercontinental cultural exchanges in Eurasia and climate change in northwestern China. The isotopic evidence indicated that human diets mainly consisted of C4 foodstuffs (presumably millet and/or animals fed with C4 foods) around 4000 calibrated years before the present (cal yr BP), corresponding to the flourishing of millet agriculture in the context of the optimal climate conditions of the mid-Holocene. Subsequently, more C3 foods (probably wheat, barley, and animals fed with C3 foods) were added to human diets post-3600 cal yr BP when the climate became cooler and drier. Such dietary variation is also consistent with the increasing intensity of long-distance exchange after 4000 cal yr BP. While many factors can lead to human dietary shifts (e.g. climate change, population growth, cultural factors, and human migration), climate may have been a key factor in Gansu and Qinghai.

  2. DNA-based stable isotope probing: a link between community structure and function

    International Nuclear Information System (INIS)

    Uhlik, Ondrej; Jecna, Katerina; Leigh, Mary Beth; Mackova, Martina; Macek, Tomas

    2009-01-01

    DNA-based molecular techniques permit the comprehensive determination of microbial diversity but generally do not reveal the relationship between the identity and the function of microorganisms. The first direct molecular technique to enable the linkage of phylogeny with function is DNA-based stable isotope probing (DNA-SIP). Applying this method first helped describe the utilization of simple compounds, such as methane, methanol or glucose and has since been used to detect microbial communities active in the utilization of a wide variety of compounds, including various xenobiotics. The principle of the method lies in providing 13C-labeled substrate to a microbial community and subsequent analyses of the 13C-DNA isolated from the community. Isopycnic centrifugation permits separating 13C-labeled DNA of organisms that utilized the substrate from 12C-DNA of the inactive majority. As the whole metagenome of active populations is isolated, its follow-up analysis provides successful taxonomic identification as well as the potential for functional gene analyses. Because of its power, DNA-SIP has become one of the leading techniques of microbial ecology research. But from other point of view, it is a labor-intensive method that requires careful attention to detail during each experimental step in order to avoid misinterpretation of results.

  3. Conjugated organic framework with three-dimensionally ordered stable structure and delocalized π clouds

    Science.gov (United States)

    Guo, Jia; Xu, Yanhong; Jin, Shangbin; Chen, Long; Kaji, Toshihiko; Honsho, Yoshihito; Addicoat, Matthew A.; Kim, Jangbae; Saeki, Akinori; Ihee, Hyotcherl; Seki, Shu; Irle, Stephan; Hiramoto, Masahiro; Gao, Jia; Jiang, Donglin

    2013-01-01

    Covalent organic frameworks are a class of crystalline organic porous materials that can utilize π–π-stacking interactions as a driving force for the crystallization of polygonal sheets to form layered frameworks and ordered pores. However, typical examples are chemically unstable and lack intrasheet π-conjugation, thereby significantly limiting their applications. Here we report a chemically stable, electronically conjugated organic framework with topologically designed wire frameworks and open nanochannels, in which the π conjugation-spans the two-dimensional sheets. Our framework permits inborn periodic ordering of conjugated chains in all three dimensions and exhibits a striking combination of properties: chemical stability, extended π-delocalization, ability to host guest molecules and hole mobility. We show that the π-conjugated organic framework is useful for high on-off ratio photoswitches and photovoltaic cells. Therefore, this strategy may constitute a step towards realizing ordered semiconducting porous materials for innovations based on two-dimensionally extended π systems. PMID:24220603

  4. Optimized multi-step NMR-crystallography approach for structural characterization of a stable quercetin solvate.

    Science.gov (United States)

    Filip, Xenia; Miclaus, Maria; Martin, Flavia; Filip, Claudiu; Grosu, Ioana Georgeta

    2017-05-10

    Herein we report the preparation and solid state structural investigation of the 1,4-dioxane-quercetin solvate. NMR crystallography methods were employed for crystal structure determination of the solvate from microcrystalline powder. The stability of the compound relative to other reported quercetin solvates is discussed and found to be in perfect agreement with the hydrogen bonding networks/supra-molecular architectures formed in each case. It is also clearly shown that NMR crystallography represents an ideal analytical tool in such cases when hydrogen-bonding networks are required to be constrained at a high accuracy level. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Combined effect of boundary layer recirculation factor and stable energy on local air quality in pearl river delta over southern China.

    Science.gov (United States)

    Li, Haowen; Wang, Baomin; Fang, Xingqin; Zhu, Wei; Fan, Qi; Liao, Zhiheng; Liu, Jian; Zhang, Asi; Fan, Shaojia

    2018-03-01

    Atmospheric boundary layer (ABL) has a significant impact on the spatial and temporal distribution of air pollutants. In order to gain a better understanding of how ABL affects the variation of air pollutants, atmospheric boundary layer observations were performed at Sanshui in the Pearl River Delta (PRD) region over Southern China during the winter of 2013. Two types of typical ABL status which could lead to air pollution were analyzed comparatively: weak vertical diffusion ability type (WVDAT) and weak horizontal transportation ability type (WHTAT). Results show: 1) WVDAT was featured with moderate wind speed, consistent wind direction, and thick inversion layer at 600 ~ 1000m above ground level (AGL), and air pollutants were restricted in the low altitude due to the stable atmospheric structure; 2) WHTAT was characterized with calm wind, varied wind direction and shallow intense ground inversion layer, and air pollutants accumulated in the local because of strong recirculation in the low ABL; 3) Recirculation Factor (RF) and Stable Energy (SE) were proved to be good indicators for horizontal transportation ability and vertical diffusion ability of the atmosphere, respectively. Combined utilization of RF and SE can be very helpful in the evaluation of air pollution potential of the ABL. Implications Air quality data from ground and meteorological data collected from radio sounding in Sanshui in Pearl River Delta show that local air quality was poor when wind reversal was pronounced or temperature stratification state is stable. It should take the combination of horizontal and vertical transportation ability of local atmosphere into consideration when evaluating local environmental bearing capacity for air pollution.

  6. Atomic-scale structure and properties of highly stable antiphase boundary defects in Fe3O4.

    Science.gov (United States)

    McKenna, Keith P; Hofer, Florian; Gilks, Daniel; Lazarov, Vlado K; Chen, Chunlin; Wang, Zhongchang; Ikuhara, Yuichi

    2014-12-10

    The complex and intriguing properties of the ferrimagnetic half metal magnetite (Fe 3 O 4 ) are of continuing fundamental interest as well as being important for practical applications in spintronics, magnetism, catalysis and medicine. There is considerable speculation concerning the role of the ubiquitous antiphase boundary (APB) defects in magnetite, however, direct information on their structure and properties has remained challenging to obtain. Here we combine predictive first principles modelling with high-resolution transmission electron microscopy to unambiguously determine the three-dimensional structure of APBs in magnetite. We demonstrate that APB defects on the {110} planes are unusually stable and induce antiferromagnetic coupling between adjacent domains providing an explanation for the magnetoresistance and reduced spin polarization often observed. We also demonstrate how the high stability of the {110} APB defects is connected to the existence of a metastable bulk phase of Fe 3 O 4 , which could be stabilized by strain in films or nanostructures.

  7. Structural changes, market concentration and vertical integration: would they lead to more stable markets

    International Nuclear Information System (INIS)

    Tahmassebi, H.

    1991-01-01

    This communication is concerned with three major developments that are likely to have significant impact on the future structure of world oil markets: oil company mergers and acquisitions, shift of exploration and production activity from the United States to overseas, and joint venture agreements between producing countries and oil companies aimed at further downstream integration by OPEC. The last two developments are likely to contribute substantially to price and market stability in the future

  8. Effect of Dietary Intake of Stable Iodine on Dose-per-unit-intake Factors for 99Tc

    Energy Technology Data Exchange (ETDEWEB)

    Strom, Daniel J.

    2003-09-30

    of stable iodine in the diet on the dose per unit intake factors for 99Tc without developing an improved biokinetic model for technetium. Specific experiments should be designed to quantitatively evaluate 99TcO4? metabolism, excretion, and secretion, as well as to evaluate its chemical toxicity It is recommended that the ICRP reexamine its biokinetics models for Tc based on nuclear medicine data that have accumulated over the years. In particular, the ICRP ignores the lactation pathway, the enhanced concentration of Tc in breast and breast milk, and enhanced concentration of Tc (and I) in the salivary glands as well as in the thyroid. The ICRP should also explicitly incorporate the effect of stable iodine in the diet into both its models for iodine and technetium. The effect of concentration of Tc in breast milk needs further study for dosimetric implications to nursing infants whose mothers may ingest 99TcO4? from groundwater sources. The ICRP should also investigate the possibility of enhanced concentration of both I and Tc in the non-lactating female breast. To do these re-evaluations of biokinetic models, new experiments designed specifically to evaluate these questions concerning the biokinetics of Tc and I are needed.

  9. Stable isotope evidence of long-term changes in North Sea food web structure

    DEFF Research Database (Denmark)

    Richardson, Katherine; Christensen, Jens Tang

    2008-01-01

    coast. Porpoises collected after ~1960 had significantly lower d15N than porpoises collected earlier. This change in d15N implies that fundamental changes in food web structure in, or nutrient availability to, the North Sea have taken place over the last ~150 yr and that most of the change occurred over...... reported here may be a reflection of a change in the isotope signature of nitrogen entering the food web. Regardless of its underlying cause, the recorded change in isotopic signature in harbour porpoises is noteworthy as it represents the first fisheries-independent documentation of a long-term temporal...

  10. Factors controlling stable isotope composition of precipitation in arid conditions: an observation network in the Tianshan Mountains, central Asia

    Directory of Open Access Journals (Sweden)

    Shengjie Wang

    2016-02-01

    Full Text Available Approximately one-third of the Earth's arid areas are distributed across central Asia. The stable isotope composition of precipitation in this region is affected by its aridity, therefore subject to high evaporation and low precipitation amount. To investigate the factors controlling stable water isotopes in precipitation in arid central Asia, an observation network was established around the Tianshan Mountains in 2012. Based on the 1052 event-based precipitation samples collected at 23 stations during 2012–2013, the spatial distribution and seasonal variation of δD and δ18O in precipitation were investigated. The values of δD and δ18O are relatively more enriched in the rainfall dominant summer months (from April to October and depleted in the drier winter months (from November to March with low D-excess due to subcloud evaporation observed at many of the driest low elevation stations. The local meteoric water line (LMWL was calculated to be δD=7.36δ18O – 0.50 (r2=0.97, p<0.01 based on the event-based samples, and δD=7.60δ18O+2.66 (r2=0.98, p<0.01 based on the monthly precipitation-weighted values. In winter, the data indicate an isotopic rain shadow effect whereby rainout leads to depletion of precipitation in the most arid region to the south of the Tianshan Mountains. The values of δ18O significantly correlate with air temperature for each station, and the best-fit equation is established as δ18O=0.78T – 16.01 (r2=0.73, p<0.01. Using daily air temperature and precipitation derived from a 0.5° (latitude×0.5° (longitude gridded data set, an isoscape of δ18O in precipitation was produced based on this observed temperature effect.

  11. Bacterioplankton communities of Crater Lake, OR: Dynamic changes with euphotic zone food web structure and stable deep water populations

    Science.gov (United States)

    Urbach, E.; Vergin, K.L.; Larson, G.L.; Giovannoni, S.J.

    2007-01-01

    The distribution of bacterial and archaeal species in Crater Lake plankton varies dramatically over depth and with time, as assessed by hybridization of group-specific oligonucleotides to RNA extracted from lakewater. Nonmetric, multidimensional scaling (MDS) analysis of relative bacterial phylotype densities revealed complex relationships among assemblages sampled from depth profiles in July, August and September of 1997 through 1999. CL500-11 green nonsulfur bacteria (Phylum Chloroflexi) and marine Group I crenarchaeota are consistently dominant groups in the oxygenated deep waters at 300 and 500 m. Other phylotypes found in the deep waters are similar to surface and mid-depth populations and vary with time. Euphotic zone assemblages are dominated either by ??-proteobacteria or CL120-10 verrucomicrobia, and ACK4 actinomycetes. MDS analyses of euphotic zone populations in relation to environmental variables and phytoplankton and zooplankton population structures reveal apparent links between Daphnia pulicaria zooplankton population densities and microbial community structure. These patterns may reflect food web interactions that link kokanee salmon population densities to community structure of the bacterioplankton, via fish predation on Daphnia with cascading consequences to Daphnia bacterivory and predation on bacterivorous protists. These results demonstrate a stable bottom-water microbial community. They also extend previous observations of food web-driven changes in euphotic zone bacterioplankton community structure to an oligotrophic setting. ?? 2007 Springer Science+Business Media B.V.

  12. Pyridine and phosphonate containing ligands for stable lanthanide complexation. An experimental and theoretical study to assess the solution structure.

    Science.gov (United States)

    Mato-Iglesias, Marta; Balogh, Edina; Platas-Iglesias, Carlos; Tóth, Eva; de Blas, Andrés; Rodríguez Blas, Teresa

    2006-12-07

    We report an experimental and theoretical study of the stability and solution structure of lanthanide complexes with two novel ligands containing pyridine units and phosphonate pendant arms on either ethane-1,2-diamine (L2) or cyclohexane-1,2-diamine (L3) backbones. Potentiometric studies have been carried out to determine the protonation constants of the ligands and the stability constants of the complexes with Gd(III) and the endogenous metal ions Zn(II) and Cu(II). While the stability constant of the GdL2 complex is too high to be determined by direct pH-potentiometric titrations, the cyclohexyl derivative GdL3 has a lower and assessable stability (log K(GdL3)=17.62). Due to the presence of the phosphonate groups, various protonated species can be detected up to pH approximately 8 for both ligands and all metal ions studied. The molecular clusters [Ln(L)(H2O)](3-).19H2O (Ln=La, Nd, Ho or Lu; L=L2 or L3) were characterized by theoretical calculations at the HF level. Our calculations provide two minimum energy geometries where the ligand adopts different conformations: twist-wrap (tw), in which the ligand wraps around the metal ion by twisting the pyridyl units relative to each other, and twist-fold (tf), where the slight twisting of the pyridyl units is accompanied by an overall folding of the two pyridine units towards one of the phosphonate groups. The relative free energies of the tw and tf conformations of [Ln(L)(H2O)]3- (L=L2, L3) complexes calculated in aqueous solution (C-PCM) by using the B3LYP model indicate that the tw form is the most stable one along the whole lanthanide series for the complexes of L3, while for those of L2 only the Gd(III) complex is more stable in the tf conformation by ca. 0.5 kcal mol-1. 1H NMR studies of the Eu(III) complex of L3 show the initial formation of the tf complex in aqueous solution, which slowly converts to the thermodynamically stable tw form. The structures calculated for the Nd(III) complexes are in reasonably

  13. Highly stable new organic-inorganic perovskite (CH₃NH₃)₂PdBr₄: synthesis, structure and physical properties.

    Science.gov (United States)

    Liu, Xixia; Huang, Tang Jiao; Zhang, Liuyang; Tang, Baoshan; Zhang, Nengduo; Shi, Diwen; Gong, Hao

    2018-01-11

    Lead halide perovskite has attracted striking attention recently due to their appealing properties. However, toxicity and stability are two main factors restricting its application. In this work, we experimentally synthesized less toxic and highly stable Pd-based hybrid perovskite after exploring different experimental conditions. This new hybrid organic-inorganic perovskite (CH₃NH₃)₂PdBr₄ was found to be an orthorhombic crystal (Cmce, Z=4) with lattice parameters a=8.00 Å, b=7.99 Å, c= 18.89 Å. The Cmce symmetry and lattices parameters were confirmed using Pawley refinement. The atoms positions were testified based on DFT calculation. This perovskite compound was determined to be a p-type semiconductor, with a resistivity of 102.9 kΩ*cm, a carrier concentration of 3.4 ×1012 /cm³ and a mobility of 23.4 cm² /(V*S). Interestingly, XRD and UV-vis measurements indicated that the phase of this new perovskite was maintained with an optical gap of 1.91 eV after leaving in air with a high humidity of 60% for 4 days, and unchanged for months in N₂ ambiance, much more stable than most existing organic-inorganic perovskites. The synthesis and various characterizations of this work further the understanding of this (CH₃NH₃)₂PdBr₄ organic-inorganic hybrid perovskite material. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Global population structure of the stable fly (Stomoxys calcitrans) inferred by mitochondrial and nuclear sequence data.

    Science.gov (United States)

    Dsouli-Aymes, N; Michaux, J; De Stordeur, E; Couloux, A; Veuille, M; Duvallet, G

    2011-03-01

    Stomoxys calcitrans (Diptera: Muscidae: Stomoxyini), a synanthropic fly with a worldwide distribution, is recognized to have an important medical and veterinary impact. We conducted a phylogeographic analysis based on several populations from five major zoogeographic regions of the world in order to analyse population genetic structure of S. calcitrans and to trace its global dispersion. Results from mitochondrial (COI, Cyt-b and ND1-16S) and nuclear (ITS2) DNA show a substantial differentiation of Oriental populations (first lineage) from the Afrotropical, Palearctic, Nearctic, Neotropical and Oceanian populations (second lineage). The divergence time analyses suggest the separation between the two lineages approximately in mid-Pleistocene. Oriental populations are isolated and would not have participated in the colonization of other regions, unlike the Afrotropical one which seems to be the source of S. calcitrans dispersion towards other regions. Demographic analyses indicate that Oriental, Afrotropical and Palearctic regions have undergone a population expansion during late Pleistocene-early Holocene. The expansion time of this cosmopolitan species could have been influenced by continental human expansions and by animal domestication. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Peculiarities of the fundamental mode structure in stable-resonator lasers upon spatially inhomogeneous amplification

    International Nuclear Information System (INIS)

    Gorbunkov, Mikhail V; Kostryukov, P V; Telegin, L S; Tunkin, V G; Yakovlev, D V

    2007-01-01

    The structure of the fundamental mode of a laser is calculated by the iteration Fox-Li method in the case of inhomogeneous unsaturated amplification produced by axially symmetric longitudinal pumping. The calculation is performed for different parameters g 1 and g 2 of the resonator within the entire stability region. It is shown that in the case of inhomogeneous amplification, the fundamental mode considerably deviates from the Gaussian mode of an empty resonator only in the so-called critical configurations of the resonator, when the quantity [arccos(g 1 g 2 ) 1/2 ]/π is zero or takes a number of values expressed by irreducible fractions m/n. For the Fresnel number N F = 9, configurations with m/n = 1/2, 2/5, 3/8, 1/3, 3/10, 1/4, 1/5, 1/6, 1/8, and 1/10 are pronounced. As N F increases, the number of critical configurations increases. The expansion in a system of Laguerre-Gaussian beams shows that the fundamental mode in critical configurations is formed by a set of beams with certain radial indices p phased in the active medium. (resonators. modes)

  16. Factors associated with health-related quality of life in stable ambulatory congestive heart failure patients: Systematic review.

    Science.gov (United States)

    Baert, Anneleen; De Smedt, Delphine; De Sutter, Johan; De Bacquer, Dirk; Puddu, Paolo Emilio; Clays, Els; Pardaens, Sofie

    2018-03-01

    Background Since improved treatment of congestive heart failure has resulted in decreased mortality and hospitalisation rates, increasing self-perceived health-related quality of life (HRQoL) has become a major goal of congestive heart failure treatment. However, an overview on predictieve factors of HRQoL is currently lacking in literature. Purpose The aim of this study was to identify key factors associated with HRQoL in stable ambulatory patients with congestive heart failure. Methods A systematic review was performed. MEDLINE, Web of Science and Embase were searched for the following combination of terms: heart failure, quality of life, health perception or functional status between the period 2000 and February 2017. Literature screening was done by two independent reviewers. Results Thirty-five studies out of 8374 titles were included for quality appraisal, of which 29 were selected for further data extraction. Four distinct categories grouping different types of variables were identified: socio-demographic characteristics, clinical characteristics, health and health behaviour, and care provider characteristics. Within the above-mentioned categories the presence of depressive symptoms was most consistently related to a worse HRQoL, followed by a higher New York Heart Association functional class, younger age and female gender. Conclusion Through a systematic literature search, factors associated with HRQoL among congestive heart failure patients were investigated. Age, gender, New York Heart Association functional class and depressive symptoms are the most consistent variables explaining the variance in HRQoL in patients with congestive heart failure. These findings are partly in line with previous research on predictors for hard endpoints in patients with congestive heart failure.

  17. The structure of mAG, a monomeric mutant of the green fluorescent protein Azami-Green, reveals the structural basis of its stable green emission

    International Nuclear Information System (INIS)

    Ebisawa, Tatsuki; Yamamura, Akihiro; Kameda, Yasuhiro; Hayakawa, Kou; Nagata, Koji; Tanokura, Masaru

    2010-01-01

    The crystal structure of a monomeric mutant of Azami-Green (mAG) from G. fascicularis was determined at 2.2 Å resolution. Monomeric Azami-Green (mAG) from the stony coral Galaxea fascicularis is the first known monomeric green-emitting fluorescent protein that is not a variant of Aequorea victoria green fluorescent protein (avGFP). These two green fluorescent proteins are only 27% identical in their amino-acid sequences. mAG is more similar in its amino-acid sequence to four fluorescent proteins: Dendra2 (a green-to-red irreversibly photoconverting fluorescent protein), Dronpa (a bright-and-dark reversibly photoswitchable fluorescent protein), KikG (a tetrameric green-emitting fluorescent protein) and Kaede (another green-to-red irreversibly photoconverting fluorescent protein). To reveal the structural basis of stable green emission by mAG, the 2.2 Å crystal structure of mAG has been determined and compared with the crystal structures of avGFP, Dronpa, Dendra2, Kaede and KikG. The structural comparison revealed that the chromophore formed by Gln62-Tyr63-Gly64 (QYG) and the fixing of the conformation of the imidazole ring of His193 by hydrogen bonds and van der Waals contacts involving His193, Arg66 and Thr69 are likely to be required for the stable green emission of mAG. The crystal structure of mAG will contribute to the design and development of new monomeric fluorescent proteins with faster maturation, brighter fluorescence, improved photostability, new colours and other preferable properties as alternatives to avGFP and its variants

  18. Synthesis, structure and topological analysis of glycine templated highly stable cadmium sulfate framework: A New Lewis Acid catalyst

    Science.gov (United States)

    Paul, Avijit Kumar

    2018-04-01

    One new open-framework two-dimensional layer, [Cd(NH3CH2COO)(SO4)], I, has been synthesized using amino acid as templating agent. Single crystal structural analysis shows that the compound crystallizes in monoclinic cell with non-centrosymmetric space group P21, a = 4.9513(1) Å, b = 7.9763(2) Å, c = 8.0967(2) Å, β = 105.917(1)° and V = 307.504(12) Å3. The compound has connectivity between the Cd-centers and the sulfate units forming a two-dimensional layer structure. Sulfate unit is coordinated to metal center with η3, μ4 mode possessing a coordination free oxygen atom. The zwitterionic form of glycine molecule is present in the structure bridging with two metal centers through μ2-mode by carboxylate oxygens. The topological analysis reveals that the two-dimensional network is formed with a novel 4- and 6-connected binodal net of (32,42,52)(34,44,54,63) topology. Although one end of the glycine molecule is free from coordination, the structure is highly stable up to 350 °C. Strong N-H⋯ O hydrogen bonding interactions play an important role in the stabilization and formation of three-dimensional supramolecular structure. The cyanosilylation of imines using the present compounds as heterogeneous catalyst indicates good catalytic behavior. The present study illustrates the usefulness of the amino acid for the structure building in less studied sulfate based framework materials as well as designing of new heterogeneous catalysts for the broad application. The compound has also been characterized through elemental analysis, PXRD, IR, SEM and TG-DT studies.

  19. The high Andes, gene flow and a stable hybrid zone shape the genetic structure of a wide-ranging South American parrot

    Directory of Open Access Journals (Sweden)

    Schaefer H Martin

    2011-06-01

    Full Text Available Abstract Background While the gene flow in some organisms is strongly affected by physical barriers and geographical distance, other highly mobile species are able to overcome such constraints. In southern South America, the Andes (here up to 6,900 m may constitute a formidable barrier to dispersal. In addition, this region was affected by cycles of intercalating arid/moist periods during the Upper/Late Pleistocene and Holocene. These factors may have been crucial in driving the phylogeographic structure of the vertebrate fauna of the region. Here we test these hypotheses in the burrowing parrot Cyanoliseus patagonus (Aves, Psittaciformes across its wide distributional range in Chile and Argentina. Results Our data show a Chilean origin for this species, with a single migration event across the Andes during the Upper/Late Pleistocene, which gave rise to all extant Argentinean mitochondrial lineages. Analyses suggest a complex population structure for burrowing parrots in Argentina, which includes a hybrid zone that has remained stable for several thousand years. Within this zone, introgression by expanding haplotypes has resulted in the evolution of an intermediate phenotype. Multivariate regressions show that present day climatic variables have a strong influence on the distribution of genetic heterogeneity, accounting for almost half of the variation in the data. Conclusions Here we show how huge barriers like the Andes and the regional environmental conditions imposed constraints on the ability of a parrot species to colonise new habitats, affecting the way in which populations diverged and thus, genetic structure. When contact between divergent populations was re-established, a stable hybrid zone was formed, functioning as a channel for genetic exchange between populations.

  20. The effect of temperature on generic stable periodic structures in the parameter space of dissipative relativistic standard map

    Science.gov (United States)

    Horstmann, Ana C. C.; Albuquerque, Holokx A.; Manchein, Cesar

    2017-05-01

    In this work, we have characterized changes in the dynamics of a two-dimensional relativistic standard map in the presence of dissipation and specially when it is submitted to thermal effects modeled by a Gaussian noise reservoir. By the addition of thermal noise in the dissipative relativistic standard map (DRSM) it is possible to suppress typical stable periodic structures (SPSs) embedded in the chaotic domains of parameter space for large enough temperature strengths. Smaller SPSs are first affected by thermal effects, starting from their borders, as a function of temperature. To estimate the necessary temperature strength capable to destroy those SPSs we use the largest Lyapunov exponent to obtain the critical temperature (TC) diagrams. For critical temperatures the chaotic behavior takes place with the suppression of periodic motion, although the temperature strengths considered in this work are not so large to convert the deterministic features of the underlying system into a stochastic ones.

  1. Stable isotopes indicate population structuring in the southwest Atlantic population of right whales (Eubalaena australis.

    Directory of Open Access Journals (Sweden)

    Morgana Vighi

    Full Text Available From the early 17th century to the 1970s southern right whales, Eubalaena australis, were subject to intense exploitation along the Atlantic coast of South America. Catches along this coast recorded by whalers originally formed a continuum from Brazil to Tierra del Fuego. Nevertheless, the recovery of the population has apparently occurred fragmentarily, and with two main areas of concentration, one off southern Brazil (Santa Catarina and another off central Argentina (Peninsula Valdés. This pattern suggests some level of heterogeneity amongst the population, which is apparently contradicted by records that traced individuals moving throughout the whole geographical extension covered by the species in the Southwest Atlantic. To test the hypothesis of the potential occurrence of discrete subpopulations exploiting specific habitats, we investigated N, C and O isotopic values in 125 bone samples obtained from whaling factories operating in the early 1970s in southern Brazil (n=72 and from contemporary and more recent strandings occurring in central Argentina (n=53. Results indicated significant differences between the two sampling areas, being δ13C and δ18O values significantly higher in samples from southern Brazil than in those from central Argentina. This variation was consistent with isotopic baselines from the two areas, indicating the occurrence of some level of structure in the Southwest Atlantic right whale population and equally that whales more likely feed in areas commonly thought to exclusively serve as nursing grounds. Results aim at reconsidering of the units currently used in the management of the southern right whale in the Southwest Atlantic Ocean. In the context of the current die-off affecting the species in Peninsula Valdés, these results also highlight the necessity to better understand movements of individuals and precisely identify their feeding areas.

  2. Stable isotopes indicate population structuring in the southwest Atlantic population of right whales (Eubalaena australis).

    Science.gov (United States)

    Vighi, Morgana; Borrell, Asunción; Crespo, Enrique A; Oliveira, Larissa R; Simões-Lopes, Paulo C; Flores, Paulo A C; García, Néstor A; Aguilar, Alex; Aguilar, Alejandro

    2014-01-01

    From the early 17th century to the 1970s southern right whales, Eubalaena australis, were subject to intense exploitation along the Atlantic coast of South America. Catches along this coast recorded by whalers originally formed a continuum from Brazil to Tierra del Fuego. Nevertheless, the recovery of the population has apparently occurred fragmentarily, and with two main areas of concentration, one off southern Brazil (Santa Catarina) and another off central Argentina (Peninsula Valdés). This pattern suggests some level of heterogeneity amongst the population, which is apparently contradicted by records that traced individuals moving throughout the whole geographical extension covered by the species in the Southwest Atlantic. To test the hypothesis of the potential occurrence of discrete subpopulations exploiting specific habitats, we investigated N, C and O isotopic values in 125 bone samples obtained from whaling factories operating in the early 1970s in southern Brazil (n=72) and from contemporary and more recent strandings occurring in central Argentina (n=53). Results indicated significant differences between the two sampling areas, being δ13C and δ18O values significantly higher in samples from southern Brazil than in those from central Argentina. This variation was consistent with isotopic baselines from the two areas, indicating the occurrence of some level of structure in the Southwest Atlantic right whale population and equally that whales more likely feed in areas commonly thought to exclusively serve as nursing grounds. Results aim at reconsidering of the units currently used in the management of the southern right whale in the Southwest Atlantic Ocean. In the context of the current die-off affecting the species in Peninsula Valdés, these results also highlight the necessity to better understand movements of individuals and precisely identify their feeding areas.

  3. Factor Structure of the Exercise Self-Efficacy Scale

    Science.gov (United States)

    Cornick, Jessica E.

    2015-01-01

    The current study utilized exercise self-efficacy ratings from undergraduate students to assess the factor structure of the Self-Efficacy to Regulate Exercise Scale (Bandura, 1997, 2006). An exploratory factor analysis (n = 759) indicated a two-factor model solution and three separate confirmatory factor analyses (n = 1,798) supported this…

  4. Factor structure underlying components of allostatic load.

    Directory of Open Access Journals (Sweden)

    Jeanne M McCaffery

    Full Text Available Allostatic load is a commonly used metric of health risk based on the hypothesis that recurrent exposure to environmental demands (e.g., stress engenders a progressive dysregulation of multiple physiological systems. Prominent indicators of response to environmental challenges, such as stress-related hormones, sympatho-vagal balance, or inflammatory cytokines, comprise primary allostatic mediators. Secondary mediators reflect ensuing biological alterations that accumulate over time and confer risk for clinical disease but overlap substantially with a second metric of health risk, the metabolic syndrome. Whether allostatic load mediators covary and thus warrant treatment as a unitary construct remains to be established and, in particular, the relation of allostatic load parameters to the metabolic syndrome requires elucidation. Here, we employ confirmatory factor analysis to test: 1 whether a single common factor underlies variation in physiological systems associated with allostatic load; and 2 whether allostatic load parameters continue to load on a single common factor if a second factor representing the metabolic syndrome is also modeled. Participants were 645 adults from Allegheny County, PA (30-54 years old, 82% non-Hispanic white, 52% female who were free of confounding medications. Model fitting supported a single, second-order factor underlying variance in the allostatic load components available in this study (metabolic, inflammatory and vagal measures. Further, this common factor reflecting covariation among allostatic load components persisted when a latent factor representing metabolic syndrome facets was conjointly modeled. Overall, this study provides novel evidence that the modeled allostatic load components do share common variance as hypothesized. Moreover, the common variance suggests the existence of statistical coherence above and beyond that attributable to the metabolic syndrome.

  5. Structural Genomics of Bacterial Virulence Factors

    Science.gov (United States)

    2006-05-01

    membrane-inserted PA pore. The model is based on the pre-pore PA63 crystal structure, channel conductance studies, and the crystal structure of α... Cyanobacteria BXA0032 and BXA0033 (pXO1-22), if fused, would belong to the COG0175 family, members of the 3’- phosphoadenosine 5’-phosphosulfate...and thiol sulfur atom directed toward the zinc. For the LF(E687C)–GM6001–Zn2+ complex (Fig. 2c–e), where LF(E687C) represents the LF E687C mutant, the

  6. A randomized study of coconut oil versus sunflower oil on cardiovascular risk factors in patients with stable coronary heart disease.

    Science.gov (United States)

    Vijayakumar, Maniyal; Vasudevan, D M; Sundaram, K R; Krishnan, Sajitha; Vaidyanathan, Kannan; Nandakumar, Sandya; Chandrasekhar, Rajiv; Mathew, Navin

    2016-01-01

    Coronary artery disease (CAD) and its pathological atherosclerotic process are closely related to lipids. Lipids levels are in turn influenced by dietary oils and fats. Saturated fatty acids increase the risk for atherosclerosis by increasing the cholesterol level. This study was conducted to investigate the impact of cooking oil media (coconut oil and sunflower oil) on lipid profile, antioxidant mechanism, and endothelial function in patients with established CAD. In a single center randomized study in India, patients with stable CAD on standard medical care were assigned to receive coconut oil (Group I) or sunflower oil (Group II) as cooking media for 2 years. Anthropometric measurements, serum, lipids, Lipoprotein a, apo B/A-1 ratio, antioxidants, flow-mediated vasodilation, and cardiovascular events were assessed at 3 months, 6 months, 1 year, and 2 years. Hundred patients in each arm completed 2 years with 98% follow-up. There was no statistically significant difference in the anthropometric, biochemical, vascular function, and in cardiovascular events after 2 years. Coconut oil even though rich in saturated fatty acids in comparison to sunflower oil when used as cooking oil media over a period of 2 years did not change the lipid-related cardiovascular risk factors and events in those receiving standard medical care. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  7. Putative new heat-stable cytotoxic and enterotoxic factors in culture supernatant of Escherichia coli isolated from drinking water

    Directory of Open Access Journals (Sweden)

    DA Ribeiro

    2011-01-01

    Full Text Available Enteric infections caused by the ingestion of contaminated water, especially by Escherichia coli, are important to define the virulence properties of these bacteria. Due to frequent infantile diarrhea in the city of Ouro Preto, Minas Gerais state, Brazil, the phenotypic and genotypic diarrheagenic properties of E. coli isolated from drinking water were studied. The culture supernatants of 39 (40% among a total of 97 E. coli isolates from drinking water were positive by suckling mouse assay and induced cytotoxic effects on Vero cells. The enterotoxic and cytotoxic activities were present in the fraction with less than 10 kDa and were not lost when heated up to 60°C and 100°C for 30 minutes. PCR assays showed that among these 39 Vero cytotoxigenic E. coli, four (10.2% were positive for ST II (estB and two (5% positive for αHly (hlyA. Gene amplification of SLT (stx 1, stx 2, ST I (estA, LT (eltI, eltII, EAST1 (astA, EHly (enhly and plasmid-encoded enterotoxin (pet were not observed. This heat-stable cytotoxic enterotoxin of E. coli is probably a new putative diarrheagenic virulence factor, as a toxin presenting these characteristics has not yet been described.

  8. A Parametric Factor Model of the Term Structure of Mortality

    DEFF Research Database (Denmark)

    Haldrup, Niels; Rosenskjold, Carsten Paysen T.

    The prototypical Lee-Carter mortality model is characterized by a single common time factor that loads differently across age groups. In this paper we propose a factor model for the term structure of mortality where multiple factors are designed to influence the age groups differently via...... parametric loading functions. We identify four different factors: a factor common for all age groups, factors for infant and adult mortality, and a factor for the "accident hump" that primarily affects mortality of relatively young adults and late teenagers. Since the factors are identified via restrictions...... on the loading functions, the factors are not designed to be orthogonal but can be dependent and can possibly cointegrate when the factors have unit roots. We suggest two estimation procedures similar to the estimation of the dynamic Nelson-Siegel term structure model. First, a two-step nonlinear least squares...

  9. Computation of the Structure Factor of Some Transition Liquid Metals

    African Journals Online (AJOL)

    Applying the solution of the Percus-Yevic equation to a one component hard sphere system and using the recently developed potential for liquid transition liquid metals, the structure factor of transition liquid metals were computed. The peak height and peak position of the structure factor of the liquid metals were studied.

  10. Interionic pair potentials and partial structure factors of compound ...

    Indian Academy of Sciences (India)

    ANIL THAKUR and P K AHLUWALIA. Physics Department, Himachal Pradesh University, Shimla 171 005, India. E-mail: anil t2001@yahoo.com. MS received 21 May 2005; revised 6 April 2007; accepted 12 July 2007. Abstract. In this paper formulae for partial structure factors have been used to study partial structure factors ...

  11. Modeling food web structure and selenium biomagnification in Lake Macquarie, New South Wales, Australia, using stable carbon and nitrogen isotopes.

    Science.gov (United States)

    Schneider, Larissa; Maher, William A; Potts, Jaimie; Taylor, Anne M; Batley, Graeme E; Krikowa, Frank; Chariton, Anthony A; Gruber, Bernd

    2015-03-01

    As a consequence of coal-fired power station operations, elevated selenium concentrations have been reported in the sediments and biota of Lake Macquarie (New South Wales, Australia). In the present study, an ecosystem-scale model has been applied to determine how selenium in a seagrass food web is processed from sediments and water through diet to predators, using stable isotopes (δ(13) C and δ(15) N) to establish the trophic position of organisms. Trophic position, habitat, and feeding zone were examined as possible factors influencing selenium bioaccumulation. Selenium concentrations ranged from 0.2 μg/g dry weight in macroalgae species to 12.9 μg/g in the carnivorous fish Gerres subfasciatus. A mean magnification factor of 1.39 per trophic level showed that selenium is biomagnifying in the seagrass food web. Habitat and feeding zone influenced selenium concentrations in invertebrates, whereas feeding zone was the only significant factor influencing selenium concentrations in fish. The sediment-water partitioning coefficient (Kd ) of 4180 showed that partitioning of selenium entering the lake to particulate organic material (POM) is occurring, and consequently availability to food webs from POM is high. Trophic transfer factors (invertebrate = 1.9; fish = 1.2) were similar to those reported for other water bodies, showing that input source is not the main determinant of the magnitude of selenium bioaccumulation in a food web, but rather the initial partitioning of selenium into bioavailable POM. Environ Toxicol Chem 2015;34:608-617. © 2014 SETAC. © 2014 SETAC.

  12. Stable phase CdS nanoparticles for optoelectronics: a study on surface morphology, structural and optical characterization

    Directory of Open Access Journals (Sweden)

    Kumar Suresh

    2016-06-01

    Full Text Available This work presents a study on the surface morphology, structure and optical behavior of stable phase cadmium sulphide (CdS nanoparticles synthesized via co-precipitation technique. Scanning electron microscopy (SEM analysis has been employed to study a cluster formation in the aggregated nanoparticles. An image analysis approach using ImageJ has been used to measure the size of nanoparticles from the SEM micrographs. Fourier transform infrared spectroscopic (FT-IR analysis identified absorption peaks of Cd–S stretching along with moisture content. X-ray diffraction (XRD analysis showed that CdS nanoparticles crystallized in wurtzite structure with a preferential orientation along (0 0 2 plane. The particle size, microstrain and lattice constants have been evaluated using XRD data. The lattice parameters of these nanoparticles were found to be shorter than the bulk value which led to lattice contraction. The optical absorption study showed a blue shift in the fundamental absorption edge indicating a quantum size effect.

  13. Impact of forest harvesting on trophic structure of eastern Canadian Boreal Shield lakes: insights from stable isotope analyses.

    Directory of Open Access Journals (Sweden)

    Patricia Glaz

    Full Text Available Perturbations on ecosystems can have profound immediate effects and can, accordingly, greatly alter the natural community. Land-use such as forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. The objective of this study was to evaluate the impact of forest harvesting on trophic structure in eastern Canadian Boreal Shield lakes. We measured carbon and nitrogen stable isotopes values for aquatic primary producers, terrestrial detritus, benthic macroinvertebrates, zooplankton and brook trout (Salvelinus fontinalis over a three-year period in eight eastern Boreal Shield lakes. Four lakes were studied before, one and two years after forest harvesting (perturbed lakes and compared with four undisturbed reference lakes (unperturbed lakes sampled at the same time. Stable isotope mixing models showed leaf-litter to be the main food source for benthic primary consumers in both perturbed and unperturbed lakes, suggesting no logging impact on allochthonous subsidies to the littoral food web. Brook trout derived their food mainly from benthic predatory macroinvertebrates in unperturbed lakes. However, in perturbed lakes one year after harvesting, zooplankton appeared to be the main contributor to brook trout diet. This change in brook trout diet was mitigated two years after harvesting. Size-related diet shift were also observed for brook trout, indicating a diet shift related to size. Our study suggests that carbon from terrestrial habitat may be a significant contribution to the food web of oligotrophic Canadian Boreal Shield lakes. Forest harvesting did not have an impact on the diet of benthic primary consumers. On the other hand, brook trout diet composition was affected by logging with greater zooplankton contribution in perturbed lakes, possibly induced by darker-colored environment in these lakes one year after logging.

  14. Impact of forest harvesting on trophic structure of eastern Canadian Boreal Shield lakes: insights from stable isotope analyses.

    Science.gov (United States)

    Glaz, Patricia; Sirois, Pascal; Archambault, Philippe; Nozais, Christian

    2014-01-01

    Perturbations on ecosystems can have profound immediate effects and can, accordingly, greatly alter the natural community. Land-use such as forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. The objective of this study was to evaluate the impact of forest harvesting on trophic structure in eastern Canadian Boreal Shield lakes. We measured carbon and nitrogen stable isotopes values for aquatic primary producers, terrestrial detritus, benthic macroinvertebrates, zooplankton and brook trout (Salvelinus fontinalis) over a three-year period in eight eastern Boreal Shield lakes. Four lakes were studied before, one and two years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. Stable isotope mixing models showed leaf-litter to be the main food source for benthic primary consumers in both perturbed and unperturbed lakes, suggesting no logging impact on allochthonous subsidies to the littoral food web. Brook trout derived their food mainly from benthic predatory macroinvertebrates in unperturbed lakes. However, in perturbed lakes one year after harvesting, zooplankton appeared to be the main contributor to brook trout diet. This change in brook trout diet was mitigated two years after harvesting. Size-related diet shift were also observed for brook trout, indicating a diet shift related to size. Our study suggests that carbon from terrestrial habitat may be a significant contribution to the food web of oligotrophic Canadian Boreal Shield lakes. Forest harvesting did not have an impact on the diet of benthic primary consumers. On the other hand, brook trout diet composition was affected by logging with greater zooplankton contribution in perturbed lakes, possibly induced by darker-colored environment in these lakes one year after logging.

  15. Population-Level Metrics of Trophic Structure Based on Stable Isotopes and Their Application to Invasion Ecology

    Science.gov (United States)

    Jackson, Michelle C.; Donohue, Ian; Jackson, Andrew L.; Britton, J. Robert; Harper, David M.; Grey, Jonathan

    2012-01-01

    Biological invasions are a significant driver of human-induced global change and many ecosystems sustain sympatric invaders. Interactions occurring among these invaders have important implications for ecosystem structure and functioning, yet they are poorly understood. Here we apply newly developed metrics derived from stable isotope data to provide quantitative measures of trophic diversity within populations or species. We then use these to test the hypothesis that sympatric invaders belonging to the same functional feeding group occupy a smaller isotopic niche than their allopatric counterparts. Two introduced, globally important, benthic omnivores, Louisiana swamp crayfish (Procambarus clarkii) and carp (Cyprinus carpio), are sympatric in Lake Naivasha, Kenya. We applied our metrics to an 8-year data set encompassing the establishment of carp in the lake. We found a strong asymmetric interaction between the two invasive populations, as indicated by inverse correlations between carp abundance and measures of crayfish trophic diversity. Lack of isotopic niche overlap between carp and crayfish in the majority of years indicated a predominantly indirect interaction. We suggest that carp-induced habitat alteration reduced the diversity of crayfish prey, resulting in a reduction in the dietary niche of crayfish. Stable isotopes provide an integrated signal of diet over space and time, offering an appropriate scale for the study of population niches, but few isotope studies have retained the often insightful information revealed by variability among individuals in isotope values. Our population metrics incorporate such variation, are robust to the vagaries of sample size and are a useful additional tool to reveal subtle dietary interactions among species. Although we have demonstrated their applicability specifically using a detailed temporal dataset of species invasion in a lake, they have a wide array of potential ecological applications. PMID:22363724

  16. [Does the GHQ-12 scoring system affect its factor structure? An exploratory study of Ibero American students].

    Science.gov (United States)

    Urzúa, Alfonso; Caqueo-Urízar, Alejandra; Bargsted, Mariana; Irarrázaval, Matías

    2015-06-01

    This study aimed to evaluate whether the scoring system of the General Health Questionnaire (GHQ-12) alters the instrument's factor structure. The method considered 1,972 university students from nine Ibero American countries. Modeling was performed with structural equations for 1, 2, and 3 latent factors. The mechanism for scoring the questions was analyzed within each type of structure. The results indicate that models with 2 and 3 factors show better goodness-of-fit. In relation to scoring mechanisms, procedure 0-1-1-1 for models with 2 and 3 factors showed the best fit. In conclusion, there appears to be a relationship between the response format and the number of factors identified in the instrument's structure. The model with the best fit was 3-factor 0-1-1-1-formatted, but 0-1-2-3 has acceptable and more stable indicators and provides a better format for two- and three-dimensional models.

  17. Trophic structure of mesopelagic fishes in the Gulf of Mexico revealed by gut content and stable isotope analyses

    Science.gov (United States)

    McClain-Counts, Jennifer P.; Demopoulos, Amanda W.J.; Ross, Steve W.

    2017-01-01

    Mesopelagic fishes represent an important component of the marine food web due to their global distributions, high abundances and ability to transport organic material throughout a large part of the water column. This study combined stable isotope (SIAs) and gut content analyses (GCAs) to characterize the trophic structure of mesopelagic fishes in the North-Central Gulf of Mexico. Additionally, this study examined whether mesopelagic fishes utilized chemosynthetic energy from cold seeps. Specimens were collected (9–25 August 2007) over three deep (>1,000 m) cold seeps at discrete depths (surface to 1,503 m) over the diurnal cycle. GCA classified 31 species (five families) of mesopelagic fishes into five feeding guilds: piscivores, large crustacean consumers, copepod consumers, generalists and mixed zooplanktivores. However, these guilds were less clearly defined based on stable isotope mixing model (MixSIAR) results, suggesting diets may be more mixed over longer time periods (weeks–months) and across co-occurring species. Copepods were likely important for the majority of mesopelagic fishes, consistent with GCA (this study) and previous literature. MixSIAR results also identified non-crustacean prey items, including salps and pteropods, as potentially important prey items for mesopelagic fishes, including those fishes not analysed in GCA (Sternoptyx spp. and Melamphaidae). Salps and other soft-bodied species are often missed in GCAs. Mesopelagic fishes had δ13C results consistent with particulate organic matter serving as the baseline organic carbon source, fueling up to three trophic levels. Fishes that undergo diel vertical migration were depleted in 15N relative to weak migrators, consistent with depth-specific isotope trends in sources and consumers, and assimilation of 15N-depleted organic matter in surface waters. Linear correlations between fish size and δ15N values suggested ontogenetic changes in fish diets for several species. While there was

  18. Influence of environmental factors on dissolved nitrate stable isotopes under denitrifying conditions - carbon sources and water isotopes

    Science.gov (United States)

    Wunderlich, A.; Meckenstock, R.; Einsiedl, F.

    2012-04-01

    Stable isotopes in dissolved nitrate are regularly used to identify sources of nitrate contamination in aquifers and water bodies. A dual isotope plot of 15N and 18O in nitrate can provide good evidence of the origin of such pollution as various sources have different isotopic signatures. Microbial denitrification changes both isotopic values by removing nitrate with lighter isotopes first, thereby increasing δ18O as well as δ15N. This change can distort the determination of sources but also has the potential to be used to identify and quantify microbial denitrification. Previous studies found a wide range of enrichment factors (ɛ) that did not allow conclusions towards the extent of microbial denitrification. However, it was found that during denitrification at each respective field site or laboratory experiment, there was a constant ratio in increase of the values of δ18O in relation to δ15N. That ratio was, however, not constant across field sites and the values published range from below 0.5 to more than 1.0. The reasons for these variations in enrichment factors and relative enrichment of oxygen compared to nitrogen are yet unknown. We conducted microcosm experiments with three different bacterial species to elucidate possible influences of environmental factors on these parameters. As a result we conclude that the type of carbon source available to denitrifying bacteria can play a role in the value of the enrichment factors, but not in the relative enrichment of the two isotopes. Specifically we found that complex hydrocarbons (toluene, benzoate) produce significantly different enrichment factors in nitrate than a simple hydrocarbon substrate (acetate). The relative enrichment of δ18O compared to δ15N was 0.86. We hypothesise that this influence is based on a variation in process kinetics of cross-membrane nitrate transport in relation to intracellular nitrate reduction. The core of the hypothesis is that nitrate transport into the cell becomes rate

  19. Étude expérimentale de structures stables en turbulence bidimensionnelle, comparaison avec une théorie de mécanique statistique

    OpenAIRE

    DENOIX , Marie-Alice

    1992-01-01

    We create two-dimensional flows within a thin layer of mercury, horizontal and subjected to a vertical uniform magnetic field. The fluid is set in motion by injecting electrical currents. We are interested in the inertial organization into stable structures of two-dimensional turbulence. With the experimental conditions in two areas of initial vorticity, we get axisymmetric structures, elliptical, or eccentric. We study these structures using visualizations and also measurements by potential ...

  20. Social cognition in schizophrenia: factor structure, clinical and functional correlates.

    Science.gov (United States)

    Buck, Benjamin E; Healey, Kristin M; Gagen, Emily C; Roberts, David L; Penn, David L

    2016-08-01

    Social cognition is consistently impaired in people with schizophrenia, separable from general neurocognition, predictive of real-world functioning and amenable to psychosocial treatment. Few studies have empirically examined its underlying factor structure. This study (1) examines the factor structure of social cognition in both a sample of individuals with schizophrenia-spectrum disorders and non-clinical controls and (2) explores relationships of factors to neurocognition, symptoms and functioning. A factor analysis was conducted on social cognition measures in a sample of 65 individuals with schizophrenia or schizoaffective disorder, and 50 control participants. The resulting factors were examined for their relationships to symptoms and functioning. Results suggested a two-factor structure in the schizophrenia sample (social cognition skill and hostile attributional style) and a three-factor structure in the non-clinical sample (hostile attributional style, higher-level inferential processing and lower-level cue detection). In the schizophrenia sample, the social cognition skill factor was significantly related to negative symptoms and social functioning, whereas hostile attributional style predicted positive and general psychopathology symptoms. The factor structure of social cognition in schizophrenia separates hostile attributional style and social cognition skill, and each show differential relationships to relevant clinical variables in schizophrenia.

  1. Structurally Deformed MoS2 for Electrochemically Stable, Thermally Resistant, and Highly Efficient Hydrogen Evolution Reaction.

    Science.gov (United States)

    Chen, Yen-Chang; Lu, Ang-Yu; Lu, Ping; Yang, Xiulin; Jiang, Chang-Ming; Mariano, Marina; Kaehr, Bryan; Lin, Oliver; Taylor, André; Sharp, Ian D; Li, Lain-Jong; Chou, Stanley S; Tung, Vincent

    2017-11-01

    The emerging molybdenum disulfide (MoS 2 ) offers intriguing possibilities for realizing a transformative new catalyst for driving the hydrogen evolution reaction (HER). However, the trade-off between catalytic activity and long-term stability represents a formidable challenge and has not been extensively addressed. This study reports that metastable and temperature-sensitive chemically exfoliated MoS 2 (ce-MoS 2 ) can be made into electrochemically stable (5000 cycles), and thermally robust (300 °C) while maintaining synthetic scalability and excellent catalytic activity through physical-transformation into 3D structurally deformed nanostructures. The dimensional transition enabled by a high throughput electrohydrodynamic process provides highly accessible, and electrochemically active surface area and facilitates efficient transport across various interfaces. Meanwhile, the hierarchically strained morphology is found to improve electronic coupling between active sites and current collecting substrates without the need for selective engineering the electronically heterogeneous interfaces. Specifically, the synergistic combination of high strain load stemmed from capillarity-induced-self-crumpling and sulfur (S) vacancies intrinsic to chemical exfoliation enables simultaneous modulation of active site density and intrinsic HER activity regardless of continuous operation or elevated temperature. These results provide new insights into how catalytic activity, electrochemical-, and thermal stability can be concurrently enhanced through the physical transformation that is reminiscent of nature, in which properties of biological materials emerge from evolved dimensional transitions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Structural, physiological, and stable carbon isotopic evidence that the enigmatic Paleozoic fossil Prototaxites formed from rolled liverwort mats.

    Science.gov (United States)

    Graham, Linda E; Cook, Martha E; Hanson, David T; Pigg, Kathleen B; Graham, James M

    2010-02-01

    New structural, nutritional, and stable carbon isotope data may resolve a long-standing mystery-the biological affinities of the fossil Prototaxites, the largest organism on land during the Late Silurian to Late Devonian (420-370 Ma). The tree trunk-shaped specimens, of varying dimensions but consistent tubular anatomy, first formed prior to vascular plant dominance. Hence, Prototaxites has been proposed to represent giant algae, fungi, or lichens, despite incompatible biochemical and anatomical observations. Our comparative analyses instead indicate that Prototaxites formed from partially degraded, wind-, gravity-, or water-rolled mats of mixotrophic liverworts having fungal and cyanobacterial associates, much like the modern liverwort genus Marchantia. We propose that the fossil body is largely derived from abundant, highly degradation-resistant, tubular rhizoids of marchantioid liverworts, intermixed with tubular microbial elements. Our concept explains previously puzzling fossil features and is consistent with evidence for liverworts and microbial associates in Ordovician-Devonian deposits, extensive ancient and modern marchantioid mats, and modern associations of liverworts with cyanobacteria and diverse types of fungi. Our interpretation indicates that liverworts were important components of Devonian ecosystems, that some macrofossils and microfossils previously attributed to "nematophytes" actually represent remains of ancient liverworts, and that mixotrophy and microbial associations were features of early land plants.

  3. Structurally Deformed MoS2 for Electrochemically Stable, Thermally Resistant, and Highly Efficient Hydrogen Evolution Reaction

    KAUST Repository

    Chen, Yen-Chang

    2017-10-12

    The emerging molybdenum disulfide (MoS2) offers intriguing possibilities for realizing a transformative new catalyst for driving the hydrogen evolution reaction (HER). However, the trade-off between catalytic activity and long-term stability represents a formidable challenge and has not been extensively addressed. This study reports that metastable and temperature-sensitive chemically exfoliated MoS2 (ce-MoS2) can be made into electrochemically stable (5000 cycles), and thermally robust (300 °C) while maintaining synthetic scalability and excellent catalytic activity through physical-transformation into 3D structurally deformed nanostructures. The dimensional transition enabled by a high throughput electrohydrodynamic process provides highly accessible, and electrochemically active surface area and facilitates efficient transport across various interfaces. Meanwhile, the hierarchically strained morphology is found to improve electronic coupling between active sites and current collecting substrates without the need for selective engineering the electronically heterogeneous interfaces. Specifically, the synergistic combination of high strain load stemmed from capillarity-induced-self-crumpling and sulfur (S) vacancies intrinsic to chemical exfoliation enables simultaneous modulation of active site density and intrinsic HER activity regardless of continuous operation or elevated temperature. These results provide new insights into how catalytic activity, electrochemical-, and thermal stability can be concurrently enhanced through the physical transformation that is reminiscent of nature, in which properties of biological materials emerge from evolved dimensional transitions.

  4. Factors limiting the operation of structures under high gradient

    International Nuclear Information System (INIS)

    Schriber, S.O.

    1986-01-01

    Factors limiting the operation of rf structures under high-gradient conditions are described. Included are recent rf measurements at laboratories in Europe, Asia, and North America and how these measurements relate to earlier data as exemplified by the use of the Kilpatrick criterion (Kp). Operation limitations will cover mechanical, geometry, thermal, and surface constraints and the associated impact on structure design, fabrication, and material selection. Generally, structures operating continuous wave (100% duty factor) appear to be limited to peak surface fields at about twice the Kilpatrick limit, whereas pulsed structures operating with pulse lengths less than a millisecond can attain peak surface fields five times the Kilpatrick limit

  5. Microbial communities of the Lemon Creek Glacier show subtle structural variation yet stable phylogenetic composition over space and time

    Directory of Open Access Journals (Sweden)

    Cody Springer Sheik

    2015-05-01

    Full Text Available Glaciers are geologically important yet transient ecosystems that support diverse, biogeochemically significant microbial communities. During the melt season glaciers undergo dramatic physical, geochemical and biological changes that exert great influence on downstream biogeochemical cycles. Thus, we sought to understand the temporal melt-season dynamics of microbial communities and associated geochemistry at the terminus of Lemon Creek Glacier (LCG in coastal southern Alaska. Due to late season snowfall, sampling of LCG occurred in three interconnected areas: proglacial Lake Thomas, the lower glacial outflow stream and the glacier’s terminus. LCG associated microbial communities were phylogenetically diverse and varied by sampling location. However, Betaproteobacteria, Alphaproteobacteria and Bacteroidetes dominated communities at all sampling locations. Strict anaerobic groups such as methanogens, SR1, and OP11 were also recovered from glacier outflows, indicating anoxic conditions in at least some portions of the LCG subglacial environment. Microbial community structure was significantly correlated with sampling location and sodium concentrations. Microbial communities sampled from terminus outflow waters exhibited day-to-day fluctuation in taxonomy and phylogenetic similarity. However, these communities were not significantly different from randomly constructed communities from all three sites. These results indicate that glacial outflows share a large proportion of phylogenetic overlap with downstream environments and that the observed significant shifts in community structure are driven by changes in relative abundance of different taxa, and not complete restructuring of communities. We conclude that LCG glacial discharge hosts a diverse and relatively stable microbiome that shifts at fine taxonomic scales in response to geochemistry and likely water residence time.

  6. Validity and factor structure of the bodybuilding dependence scale

    OpenAIRE

    Smith, D; Hale, B

    2004-01-01

    Objectives: To investigate the factor structure, validity, and reliability of the bodybuilding dependence scale and to investigate differences in bodybuilding dependence between men and women and competitive and non-competitive bodybuilders.

  7. Calculation of coupling factor for double-period accelerating structure

    International Nuclear Information System (INIS)

    Bian Xiaohao; Chen Huaibi; Zheng Shuxin

    2005-01-01

    In the design of the linear accelerating structure, the coupling factor between cavities is a crucial parameter. The error of coupling factor accounts for the electric or magnetic field error mainly. To accurately design the coupling iris, the accurate calculation of coupling factor is essential. The numerical simulation is widely used to calculate the coupling factor now. By using MAFIA code, two methods have been applied to calculate the dispersion characteristics of the single-period structure, one method is to simulate the traveling wave mode by the period boundary condition; another method is to simulate the standing wave mode by the electrical boundary condition. In this work, the authors develop the two methods to calculate the coupling factor of double-period accelerating structure. Compared to experiment, the results for both methods are very similar, and in agreement with measurement within 15% deviation. (authors)

  8. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  9. Factor structure of the intolerance of uncertainty scale for children.

    Science.gov (United States)

    Cornacchio, Danielle; Sanchez, Amanda L; Coxe, Stefany; Roy, Amy; Pincus, Donna B; Read, Kendra L; Holaway, Robert M; Kendall, Philip C; Comer, Jonathan S

    2018-01-01

    Intolerance of uncertainty (IU), a dispositional negative orientation toward uncertainty and its consequences, has been studied in adults, but research has only recently examined IU in youth. Despite some advances, little is known about the factor structure of measures of IU in youth. The present study used confirmatory factor analysis to examine the structure of IU as measured by the Intolerance of Uncertainty Scale for Children (IUSC; Comer et al., 2009) in a sample of youth (N=368) 9-18 years of age (M age =12.47) with and without anxiety disorders and their mothers. Findings demonstrated multiple acceptable factor structures: a correlated factors 2-factor structure and a bifactor model where a general factor underlies all items. While the bifactor model provides better fit and reliability to the data, multivariate analyses indicated that the 2-factor structure distinguishes apprehensive anxiety regarding future events (prospective IU) from present-focused inhibition of behavior due to uncertainty and negative reactions to the presence of uncertainty (inhibitory IU); a total IU score predicted all anxiety domains for self- and parent-reports except for parent-report harm avoidance. Findings are discussed in terms of consistency of IU across adult and youth samples, and how results can inform treatment efforts and etiologic models of IU and anxiety. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Evidence Regarding the Internal Structure: Confirmatory Factor Analysis

    Science.gov (United States)

    Lewis, Todd F.

    2017-01-01

    American Educational Research Association (AERA) standards stipulate that researchers show evidence of the internal structure of instruments. Confirmatory factor analysis (CFA) is one structural equation modeling procedure designed to assess construct validity of assessments that has broad applicability for counselors interested in instrument…

  11. A two-factor structure of first rank symptoms in patients with a psychotic disorder.

    Science.gov (United States)

    Heering, Henriette D; van Haren, Neeltje E M; Derks, Eske M

    2013-07-01

    Kurt Schneider defined 'first rank symptoms' (FRS) of psychosis. Previous research found two clusters of FRS: 'loss of ego bound' symptoms (e.g., delusions of external control) and auditory hallucinations (e.g, commenting voices). In patients with a psychosis we investigated whether FRS are a separate cluster within the group of positive symptoms, consisting of two underlying factors that are stable over time. We conducted a principal axis factor analysis (PAF) at baseline (n = 857) and a confirmative factor analysis (CFA) at three-year follow-up (n = 414) on (FRS) symptom score. Also, we investigated the stability of the two-factor structure of FRS over the interval. PAF on 16 items representing positive symptoms at baseline revealed two factors with eigenvalues > 1. FRS-delusional self experience (thought withdrawal, thought broadcasting, thought insertion, and beliefs that impulses and/or actions are controlled by an outside force) clustered in one factor and FRS-auditory hallucinations (auditory hallucinations, conversational voices, and voices commenting on one's actions) in the second factor. Furthermore, CFA on the FRS-items at follow-up confirmed the two-factor structure of FRS. FRS delusional self experience and FRS-auditory hallucinations at baseline were significantly associated with the same factors at three-year follow-up (FRS-delusional self experience: r = 0.38; FRS-auditory hallucinations r = 0.47). Hence, our findings confirm a two-factor structure of first rank symptoms, i.e. FRS-delusional self experience and FRS-auditory hallucinations, with a moderate to large internal coherence within each factor and relative stability over time. Future studies on self-processes may contribute to our understanding of the pathophysiology of first rank symptoms. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Factor Structure of Japanese Versions of Two Emotional Intelligence Scales

    Science.gov (United States)

    Fukuda, Eriko; Saklofske, Donald H.; Tamaoka, Katsuo; Fung, Tak Shing; Miyaoka, Yayoi; Kiyama, Sachiko

    2011-01-01

    This article reports the psychometric properties of two emotional intelligence measures translated into Japanese. Confirmatory factor analysis (CFA) was conducted to examine the factor structure of a Japanese version of the Wong and Law Emotional Intelligence Scale (WLEIS) completed by 310 Japanese university students. A second study employed CFA…

  13. The relevancy between structural factors and enriching the ...

    African Journals Online (AJOL)

    The present investigation Is done to determine the structural factors and prioritize the efficacy of each factors on enriching the managers of Saderat bank branches of Tehran province. The present investigation is practical considering its purpose, and descriptive (correlation kind) considering data assemblage. Statistical ...

  14. Factor structure of functional state of primary school age children

    Directory of Open Access Journals (Sweden)

    Davidenko O.V.

    2011-02-01

    Full Text Available The examination of primary school children to determine the ranking of significant factors that determine the structure of their functional state depending on the level of physical health. It is shown that the main factor in the structure of the functional state of younger schoolchildren in low-and lower-middle level of physical fitness is selected morpho-functional status, which characterizes the functions of the body at rest. For children with average or above average level of physical fitness is a leading factor in physical fitness of schoolchildren.

  15. A New Look at the Big Five Factor Structure through Exploratory Structural Equation Modeling

    Science.gov (United States)

    Marsh, Herbert W.; Ludtke, Oliver; Muthen, Bengt; Asparouhov, Tihomir; Morin, Alexandre J. S.; Trautwein, Ulrich; Nagengast, Benjamin

    2010-01-01

    NEO instruments are widely used to assess Big Five personality factors, but confirmatory factor analyses (CFAs) conducted at the item level do not support their a priori structure due, in part, to the overly restrictive CFA assumptions. We demonstrate that exploratory structural equation modeling (ESEM), an integration of CFA and exploratory…

  16. Factor Structure in Commodity Futures Return and Volatility

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Lunde, Asger; Olesen, Kasper Vinther

    Using data on more than 750 million futures trades during 2004-2013, we analyze eight stylized facts of commodity price and volatility dynamics in the post financialization period. We pay particular attention to the factor structure in returns and volatility and to commodity market integration...... with the equity market. We find evidence of a factor structure in daily commodity futures returns. However, the factor structure in daily commodity futures volatility is even stronger than in returns. When computing model-free realized commodity betas with the stock market we find that they were high during 2008......-2010 but have since returned to the pre-crisis level close to zero. The common factor in commodity volatility is nevertheless clearly related to stock market volatility. We conclude that, while commodity markets appear to again be segmented from the equity market when only returns are considered, commodity...

  17. Factor Structure in Commodity Futures Return and Volatility

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Lunde, Asger; Olesen, Kasper Vinther

    -2010 but have since returned to the pre-crisis level close to zero. The common factor in commodity volatility is nevertheless clearly related to stock market volatility. We conclude that, while commodity markets appear to again be segmented from the equity market when only returns are considered, commodity......Using data on more than 750 million futures trades during 2004-2013, we analyze eight stylized facts of commodity price and volatility dynamics in the post financialization period. We pay particular attention to the factor structure in returns and volatility and to commodity market integration...... with the equity market. We find evidence of a factor structure in daily commodity futures returns. However, the factor structure in daily commodity futures volatility is even stronger than in returns. When computing model-free realized commodity betas with the stock market we find that they were high during 2008...

  18. Factor Structure in Commodity Futures Return and Volatility

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Lunde, Asger; Olesen, Kasper Vinther

    with the equity market. We find evidence of a factor structure in daily commodity futures returns. However, the factor structure in daily commodity futures volatility is even stronger than in returns. When computing model-free realized commodity betas with the stock market we find that they were high during 2008......Using data on more than 750 million futures trades during 2004-2013, we analyze eight stylized facts of commodity price and volatility dynamics in the post financialization period. We pay particular attention to the factor structure in returns and volatility and to commodity market integration......-2010 but have since returned to the pre-crisis level close to zero. The common factor in commodity volatility is nevertheless clearly related to stock market volatility. We conclude that, while commodity markets appear to again be segmented from the equity market when only returns are considered, commodity...

  19. Factor structure of psychopathy among methadone maintenance patients.

    Science.gov (United States)

    Darke, S; Kaye, S; Finlay-Jones, R; Hall, W

    1998-01-01

    The proposed two-factor structure of the Psychopathy Checklist (Revised) was assessed by confirmatory factor analyses on a sample of 376 community and prison based methadones maintenance patients. Confirmatory factor analyses indicated that the two-factor model proposed by previous researchers did not fit well with the data from this population. Exploratory analyses extracted five interpretable factors, three psychological factors (glibness/manipulative, callousness, irresponsibility), and two behavioral factors (criminal behaviors, promiscuity), which accounted for 61% of the variance. The data provided support for the psychometric reliability of the PCL-R, as indicated by a Chronbach's alpha of 0.83, weighted kappas for concordance between raters ranging from 0.51 to 1.00, and 100% agreement on diagnoses of psychopathy between raters. The data indicate that a two-factor structure does not adequately capture the dimensions of psychopathy in this population. While the factors do fall into distinct psychological and behavioral dimensions, more than two general factors are required to describe the dimensions of psychopathy.

  20. Traditional Risk Factors Versus Biomarkers for Prediction of Secondary Events in Patients With Stable Coronary Heart Disease: From the Heart and Soul Study.

    Science.gov (United States)

    Beatty, Alexis L; Ku, Ivy A; Bibbins-Domingo, Kirsten; Christenson, Robert H; DeFilippi, Christopher R; Ganz, Peter; Ix, Joachim H; Lloyd-Jones, Donald; Omland, Torbjørn; Sabatine, Marc S; Schiller, Nelson B; Shlipak, Michael G; Skali, Hicham; Takeuchi, Madoka; Vittinghoff, Eric; Whooley, Mary A

    2015-07-06

    Patients with stable coronary heart disease (CHD) have widely varying prognoses and treatment options. Validated models for risk stratification of patients with CHD are needed. We sought to evaluate traditional and novel risk factors as predictors of secondary cardiovascular (CV) events, and to develop a prediction model that could be used to risk stratify patients with stable CHD. We used independent derivation (912 participants in the Heart and Soul Study) and validation (2876 participants in the PEACE trial) cohorts of patients with stable CHD to develop a risk prediction model using Cox proportional hazards models. The outcome was CV events, defined as myocardial infarction, stroke, or CV death. The annual rate of CV events was 3.4% in the derivation cohort and 2.2% in the validation cohort. With the exception of smoking, traditional risk factors (including age, sex, body mass index, hypertension, dyslipidemia, and diabetes) did not emerge as the top predictors of secondary CV events. The top 4 predictors of secondary events were the following: N-terminal pro-type brain natriuretic peptide, high-sensitivity cardiac troponin T, urinary albumin:creatinine ratio, and current smoking. The 5-year C-index for this 4-predictor model was 0.73 in the derivation cohort and 0.65 in the validation cohort. As compared with variables in the Framingham secondary events model, the Heart and Soul risk model resulted in net reclassification improvement of 0.47 (95% CI 0.25 to 0.73) in the derivation cohort and 0.18 (95% CI 0.01 to 0.40) in the validation cohort. Novel risk factors are superior to traditional risk factors for predicting 5-year risk of secondary events in patients with stable CHD. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  1. Factor structure of borderline personality disorder symptomatology in adolescents.

    Science.gov (United States)

    Speranza, Mario; Pham-Scottez, Alexandra; Revah-Levy, Anne; Barbe, Remy P; Perez-Diaz, Fernando; Birmaher, Boris; Corcos, Maurice

    2012-04-01

    To examine the factor structure of the Diagnostic and Statistical Manual of Mental Disorders (DSM), Fourth Edition, criteria for borderline personality disorder (BPD) in a sample of adolescents with a borderline symptomatology. The latent structure of borderline criteria, assessed with the Structured Interview for DSM-IV Personality, was explored with a principal factor analysis in a sample of 107 adolescents with a borderline symptomatology drawn from a European research project on BPDs. The principal component analysis revealed 2 homogeneous factors accounting for 66.8% of the variance. The first factor included internally oriented criteria, such as avoidance of abandonment, identity disturbance, chronic feeling of emptiness, and stress-related paranoid ideation. The second factor included externally oriented criteria, such as unstable relationships, impulsivity, suicidal or self-mutilating behaviours, and inappropriate anger. Affective instability was the only criterion loading on both factors. The results of our study suggests that an internal or external dichotomy may be an appropriate way to conceptualize the structure of borderline criteria in adolescents with a borderline symptomatology, with affective instability being a core feature of BPD at this age.

  2. Stable and High OSNR Compound Linear-Cavity Single-Longitudinal-Mode Erbium-Doped Silica Fiber Laser Based on an Asymmetric Four-Cavity Structure

    International Nuclear Information System (INIS)

    Feng Ting; Yan Feng-Ping; Li Qi; Peng Wan-Jing; Feng Su-Chun; Wen Xiao-Dong; Tan Si-Yu; Liu Peng

    2012-01-01

    We propose a stable and high optical signal-to-noise ratio (OSNR) compound linear-cavity single-longitudinal-mode (SLM) erbium-doped silica fiber laser. It consists of three uniform fiber Bragg gratings (FBGs) and two fiber couplers to form a simple asymmetric four-cavity structure to select the longitudinal mode. The stable SLM operation at the wavelength of 1544.053 nm with a 3 dB bandwidth of 0.014 nm and an OSNR of ∼60 dB was verified experimentally. Under laboratory conditions, a power fluctuation performance of less than 0.05 dB for 5 h and wavelength variation of less than 0.01 nm for about 150 min is demonstrated. Finally, the characteristic of laser output power as a function of pump power is investigated. The proposed system provides a simple and cost-effective approach to realize a stable SLM fiber laser

  3. Structural Fingerprints of Transcription Factor Binding Site Regions

    Directory of Open Access Journals (Sweden)

    Peter Willett

    2009-03-01

    Full Text Available Fourier transforms are a powerful tool in the prediction of DNA sequence properties, such as the presence/absence of codons. We have previously compiled a database of the structural properties of all 32,896 unique DNA octamers. In this work we apply Fourier techniques to the analysis of the structural properties of human chromosomes 21 and 22 and also to three sets of transcription factor binding sites within these chromosomes. We find that, for a given structural property, the structural property power spectra of chromosomes 21 and 22 are strikingly similar. We find common peaks in their power spectra for both Sp1 and p53 transcription factor binding sites. We use the power spectra as a structural fingerprint and perform similarity searching in order to find transcription factor binding site regions. This approach provides a new strategy for searching the genome data for information. Although it is difficult to understand the relationship between specific functional properties and the set of structural parameters in our database, our structural fingerprints nevertheless provide a useful tool for searching for function information in sequence data. The power spectrum fingerprints provide a simple, fast method for comparing a set of functional sequences, in this case transcription factor binding site regions, with the sequences of whole chromosomes. On its own, the power spectrum fingerprint does not find all transcription factor binding sites in a chromosome, but the results presented here show that in combination with other approaches, this technique will improve the chances of identifying functional sequences hidden in genomic data.

  4. HYDROLYSIS OF STARCH BY THERMO-AND PH-STABLE GLUCOAMYLASE AT CHANGE PHYSICO-CHEMICAL FACTORS

    Directory of Open Access Journals (Sweden)

    V. S. Grigirov

    2013-01-01

    Full Text Available Regularity of the change rate of the enzymatic reactions depending on different temperatures, pH values in the formation and decay of the enzyme-substrate complex was investigated. Found that the kinetics of hydrolysis of starch by the action of heat and pH stable glucoamylases is complex as evidenced by the change in the value Km, which is a measure of the affinity of the enzyme to the substrate, active centers studied glucoamylases and starch undergo conformational changes at pH 4,0-5,0; 4,5-5,5 and a temperature of 60-65 °C.

  5. Calculation of coupling factor for the heterogeneous accelerating structure

    International Nuclear Information System (INIS)

    Bian Xiaohao; Chen Huaibi; Zheng Shuxin

    2006-01-01

    The converging part of electron accelerator is designed to converge the phase of injecting electrons, improving the beam quality of the accelerator. It is very crucial to calculate the coupling factor between cavities and to design the geometry structure of the coupling irises. By the E module of code MAFIA, the authors calculate the frequency of every single resonant cavity and the two eigenfrequencies of two-cavitiy line. Then we get the coupling factor between the two cavities. This method can be used to design the geometry structure of the coupling isises between every two cavities. Compared to experiment, the results of the method is very accurate. (authors)

  6. Partial structure factors and orientational correlations in liquid HI

    International Nuclear Information System (INIS)

    Andreani, C.; Nardone, M.; Ricci, F.P.

    1993-01-01

    The three atomic partial structure factors of orthobaric liquid HI at 253 K derived from neutron diffraction experiments are presented. The analysis of these structure factors and of the corresponding pair distribution functions indicates that the molecular center of mass distribution function is essentially that of a monoatomic Lennard-Jones fluid and that the anisotropic part of the intermolecular potential is able to build up orientational correlations between molecular axes without however giving rise to well defined correlations between the intermolecular axis and the molecular axis. These findings are consistent with an anisotropic part of the intermolecular potential due essentially to electric multipoles. (authors). 4 figs., 4 refs

  7. The structure of musical preferences: a five-factor model.

    Science.gov (United States)

    Rentfrow, Peter J; Goldberg, Lewis R; Levitin, Daniel J

    2011-06-01

    Music is a cross-cultural universal, a ubiquitous activity found in every known human culture. Individuals demonstrate manifestly different preferences in music, and yet relatively little is known about the underlying structure of those preferences. Here, we introduce a model of musical preferences based on listeners' affective reactions to excerpts of music from a wide variety of musical genres. The findings from 3 independent studies converged to suggest that there exists a latent 5-factor structure underlying music preferences that is genre free and reflects primarily emotional/affective responses to music. We have interpreted and labeled these factors as (a) a Mellow factor comprising smooth and relaxing styles; (b) an Unpretentious factor comprising a variety of different styles of sincere and rootsy music such as is often found in country and singer-songwriter genres; (c) a Sophisticated factor that includes classical, operatic, world, and jazz; (d) an Intense factor defined by loud, forceful, and energetic music; and (e) a Contemporary factor defined largely by rhythmic and percussive music, such as is found in rap, funk, and acid jazz. The findings from a fourth study suggest that preferences for the MUSIC factors are affected by both the social and the auditory characteristics of the music. 2011 APA, all rights reserved

  8. The Structure of Musical Preferences: A Five-Factor Model

    Science.gov (United States)

    Rentfrow, Peter J.; Goldberg, Lewis R.; Levitin, Daniel J.

    2011-01-01

    Music is a cross-cultural universal, a ubiquitous activity found in every known human culture. Individuals demonstrate manifestly different preferences in music, and yet relatively little is known about the underlying structure of those preferences. Here, we introduce a model of musical preferences based on listeners’ affective reactions to excerpts of music from a wide variety of musical genres. The findings from three independent studies converged to suggest that there exists a latent five-factor structure underlying music preferences that is genre-free, and reflects primarily emotional/affective responses to music. We have interpreted and labeled these factors as: 1) a Mellow factor comprising smooth and relaxing styles; 2) an Urban factor defined largely by rhythmic and percussive music, such as is found in rap, funk, and acid jazz; 3) a Sophisticated factor that includes classical, operatic, world, and jazz; 4) an Intense factor defined by loud, forceful, and energetic music; and 5) a Campestral factor comprising a variety of different styles of direct, and rootsy music such as is often found in country and singer-songwriter genres. The findings from a fourth study suggest that preferences for the MUSIC factors are affected by both the social and auditory characteristics of the music. PMID:21299309

  9. Latent factor structure of a behavioral economic marijuana demand curve.

    Science.gov (United States)

    Aston, Elizabeth R; Farris, Samantha G; MacKillop, James; Metrik, Jane

    2017-08-01

    Drug demand, or relative value, can be assessed via analysis of behavioral economic purchase task performance. Five demand indices are typically obtained from drug purchase tasks. The goal of this research was to determine whether metrics of marijuana reinforcement from a marijuana purchase task (MPT) exhibit a latent factor structure that efficiently characterizes marijuana demand. Participants were regular marijuana users (n = 99; 37.4% female, 71.5% marijuana use days [5 days/week], 15.2% cannabis dependent) who completed study assessments, including the MPT, during a baseline session. Principal component analysis was used to examine the latent structure underlying MPT indices. Concurrent validity was assessed via examination of relationships between latent factors and marijuana use, past quit attempts, and marijuana expectancies. A two-factor solution was confirmed as the best fitting structure, accounting for 88.5% of the overall variance. Factor 1 (65.8% variance) reflected "Persistence," indicating sensitivity to escalating marijuana price, which comprised four MPT indices (elasticity, O max , P max , and breakpoint). Factor 2 (22.7% variance) reflected "Amplitude," indicating the amount consumed at unrestricted price (intensity). Persistence factor scores were associated with fewer past marijuana quit attempts and lower expectancies of negative use outcomes. Amplitude factor scores were associated with more frequent use, dependence symptoms, craving severity, and positive marijuana outcome expectancies. Consistent with research on alcohol and cigarette purchase tasks, the MPT can be characterized with a latent two-factor structure. Thus, demand for marijuana appears to encompass distinct dimensions of price sensitivity and volumetric consumption, with differential relations to other aspects of marijuana motivation.

  10. Using Multilevel Factor Analysis with Clustered Data: Investigating the Factor Structure of the Positive Values Scale

    Science.gov (United States)

    Huang, Francis L.; Cornell, Dewey G.

    2016-01-01

    Advances in multilevel modeling techniques now make it possible to investigate the psychometric properties of instruments using clustered data. Factor models that overlook the clustering effect can lead to underestimated standard errors, incorrect parameter estimates, and model fit indices. In addition, factor structures may differ depending on…

  11. 2,6,10-Tris(dialkylamino)-trioxatriangulenium Ions. Synthesis, Structure, and Properties of Exceptionally Stable Carbenium Ions

    DEFF Research Database (Denmark)

    Laursen, Bo W.; Krebs, Frederik C; Nielsen, Merete F.

    1998-01-01

    is expressed as the pK(R+) value, which is determined in strongly basic nonaqueous solution on-the basis of a new acidity function C-. The pK(R+) value of 5a is measured to be 19.7, which is 10 orders of magnitude higher than the values found for the most stable carbenium ions previously reported...

  12. Stable isotope discrimination factors and between-tissue isotope comparisons for bone and skin from captive and wild green sea turtles (Chelonia mydas).

    Science.gov (United States)

    Turner Tomaszewicz, Calandra N; Seminoff, Jeffrey A; Price, Mike; Kurle, Carolyn M

    2017-11-30

    The ecological application of stable isotope analysis (SIA) relies on taxa- and tissue-specific stable carbon (Δ 13 C) and nitrogen (Δ 15 N) isotope discrimination factors, determined with captive animals reared on known diets for sufficient time to reflect dietary isotope ratios. However, captive studies often prohibit lethal sampling, are difficult with endangered species, and reflect conditions not experienced in the wild. We overcame these constraints and determined the Δ 13 C and Δ 15 N values for skin and cortical bone from green sea turtles (Chelonia mydas) that died in captivity and evaluated the utility of a mathematical approach to predict discrimination factors. Using stable carbon (δ 13 C values) and nitrogen (δ 15 N values) isotope ratios from captive and wild turtles, we established relationships between bone stable isotope (SI) ratios and those from skin, a non-lethally sampled tissue, to facilitate comparisons of SI ratios among studies using multiple tissues. The mean (±SD) Δ 13 C and Δ 15 N values (‰) between skin and bone from captive turtles and their diet (non-lipid-extracted) were 2.3 ± 0.3 and 4.1 ± 0.4 and 2.1 ± 0.6 and 5.1 ± 1.1, respectively. The mathematically predicted Δ 13 C and Δ 15 N values were similar (to within 1‰) to the experimentally derived values. The mean δ 15 N values from bone were higher than those from skin for captive (+1.0 ± 0.9‰) and wild (+0.8 ± 1.0‰) turtles; the mean δ 13 C values from bone were lower than those from skin for wild turtles (-0.6 ± 0.9‰), but the same as for captive turtles. We used linear regression equations to describe bone vs skin relationships and create bone-to-skin isotope conversion equations. For sea turtles, we provide the first (a) bone-diet SI discrimination factors, (b) comparison of SI ratios from individual-specific bone and skin, and (c) evaluation of the application of a mathematical approach to predict stable isotope discrimination factors. Our approach

  13. Factor Structure of the WPPSI in Mental Health Clinic Settings.

    Science.gov (United States)

    Haynes, Jack P.; Atkinson, David

    1984-01-01

    Factor-analyzed the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) scores of emotionally disturbed children (N=181). The results suggested that the structure of intelligence for emotionally disturbed children is similar to that for normal children. WPPSI profile analysis that uses subtest scores may be invalid in clinical settings.…

  14. Matrix factorization method for the Hamiltonian structure of ...

    Indian Academy of Sciences (India)

    We demonstrate that the process of matrix factorization provides a systematic mathematical method to investigate the Hamiltonian structure of non-linear evolution equations characterized by hereditary operators with Nijenhuis property. Author Affiliations. S Ghosh1 B Talukdar1 S Chakraborti2. Department of Physics ...

  15. Factor structure and psychometric properties of the General Health ...

    African Journals Online (AJOL)

    Purpose: There is little information about the reliability and validity of the 12-item General Health Questionnaire (GHQ-12) in Ghana. This study sought to examine the reliability and factor structure of the GHQ-12 in Ghanaian adolescents. Methods: High school students (N = 770) completed the GHQ-12 and the Adolescent ...

  16. Factor structure of the Behavior Flexibility Rating Scale (BFRS)

    NARCIS (Netherlands)

    Pituch, K.A.; Green, V.A.; Sigafoos, J.; Itchon, J.; O'Reilly, M.F.; Lancioni, G.E.; Didden, H.C.M.

    2007-01-01

    The Behavior Flexibility Rating Scale (BFRS) is designed to assess insistence on sameness or lack of behavioral flexibility, which is often associated with autism and other developmental disabilities. This study was designed to assess the factor structure of this scale for a sample of 968

  17. Structure factor of liquid caesium and sodium-caesium alloys

    International Nuclear Information System (INIS)

    Huijben, M.J.; Lugt, W. van der

    1977-01-01

    X-ray transmission diffraction experiments have been carried out for liquid sodium, potassium, caesium and some sodium-caesium alloys. The structure factor of liquid pure caesium at the melting point can be scaled down to those of sodium and potassium with reasonable accuracy. (author)

  18. Gregory Research Beliefs Scale: Factor Structure and Internal Consistency

    Science.gov (United States)

    Gregory, Virgil L., Jr.

    2010-01-01

    Objective: This study evaluates the factor structure and internal consistency of the Gregory Research Beliefs Scale (GRBS). Method: Data were collected from subject matter experts, a pilot study, an online sample, and a classroom sample. Psychometric analyses were conducted after combining the online and classroom samples. Results: An a priori…

  19. Structural uncertainty in air mass factor calculation for NO

    NARCIS (Netherlands)

    Lorente Delgado, Alba; Folkert Boersma, K.; Yu, Huan; Dörner, Steffen; Hilboll, Andreas; Richter, Andreas; Liu, Mengyao; Lamsal, Lok N.; Barkley, Michael; Smedt, De Isabelle; Roozendael, Van Michel; Wang, Yang; Wagner, Thomas; Beirle, Steffen; Lin, Jin Tai; Krotkov, Nickolay; Stammes, Piet; Wang, Ping; Eskes, Henk J.; Krol, Maarten

    2017-01-01

    Air mass factor (AMF) calculation is the largest source of uncertainty in NO2 and HCHO satellite retrievals in situations with enhanced trace gas concentrations in the lower troposphere. Structural uncertainty arises when different retrieval methodologies are applied within the scientific community

  20. Effectiveness of a structured checklist of risk factors in identifying ...

    African Journals Online (AJOL)

    Background: Gestational diabetes mellitus (GDM) is associated with increased risk of mortality and morbidity for pregnant women and newborns. Identifying pregnant women with risk factors for GDM based on the clinical suspicion is a popular approach. However, the effectiveness of the use of a structured checklist of risk ...

  1. The factor structure of the Maslach Burnout Inventory Human ...

    African Journals Online (AJOL)

    kirstam

    The factor structure of the Maslach Burnout Inventory. Human Services Survey across a sample of client service employees. C. Steyn. 6ABSTRACT. 12The negative consequences of burnout in the client service environment point to the importance of further research into the manner in which the unique challenges faced by ...

  2. 'Mum never loved me.' How structural factors influence adolescent ...

    African Journals Online (AJOL)

    How structural factors influence adolescent sexual and reproductive health through parent–child connectedness: A qualitative study in rural Tanzania. ... Connectedness was related to SRH in a bi-directional way: lack of connectedness was linked to young people's low self-esteem and risky sexual behaviour while ...

  3. Structure factors for tunneling ionization rates of molecules

    DEFF Research Database (Denmark)

    Madsen, L.B.; Jensen, F.; Tolstikhin, O.I.

    2013-01-01

    Within the weak-field asymptotic theory, the dependence of the tunneling ionization rate of a molecule in a static electric field on its orientation with respect to the field is determined by the structure factor for the highest occupied molecular orbital (HOMO). An accurate determination of this...

  4. Corporate financial structure, misallocation and total factor productivity

    NARCIS (Netherlands)

    Uras, R.B.

    2014-01-01

    This paper studies the quantitative relevance of the cross-sectional dispersion of corporate financial structure in explaining the intra-industry allocation efficiency of productive factors. I solve a heterogeneous firms model with financial constraints and distortions to the marginal rental-rate of

  5. Latent Factor Structure of DSM-5 Posttraumatic Stress Disorder

    Science.gov (United States)

    Gentes, Emily; Dennis, Paul A.; Kimbrel, Nathan A.; Kirby, Angela C.; Hair, Lauren P.; Beckham, Jean C.; Calhoun, Patrick S.

    2015-01-01

    The current study examined the latent factor structure of posttraumatic stress disorder (PTSD) based on DSM-5 criteria in a sample of participants (N = 374) recruited for studies on trauma and health. Confirmatory factor analyses (CFA) were used to compare the fit of the previous 3-factor DSM-IV model of PTSD to the 4-factor model specified in DSM-5 as well as to a competing 4-factor “dysphoria” model (Simms, Watson, & Doebbeling, 2002) and a 5-factor (Elhai et al., 2011) model of PTSD. Results indicated that the Elhai 5-factor model (re-experiencing, active avoidance, emotional numbing, dysphoric arousal, anxious arousal) provided the best fit to the data, although substantial support was demonstrated for the DSM-5 4-factor model. Low factor loadings were noted for two of the symptoms in the DSM-5 model (psychogenic amnesia and reckless/self-destructive behavior), which raises questions regarding the adequacy of fit of these symptoms with other core features of the disorder. Overall, the findings from the present research suggest the DSM-5 model of PTSD is a significant improvement over the previous DSM-IV model of PTSD. PMID:26366290

  6. Stable interaction between the human proliferating cell nuclear antigen loader complex Ctf18-replication factor C (RFC) and DNA polymerase {epsilon} is mediated by the cohesion-specific subunits, Ctf18, Dcc1, and Ctf8.

    Science.gov (United States)

    Murakami, Takeshi; Takano, Ryuji; Takeo, Satoshi; Taniguchi, Rina; Ogawa, Kaori; Ohashi, Eiji; Tsurimoto, Toshiki

    2010-11-05

    One of the proliferating cell nuclear antigen loader complexes, Ctf18-replication factor C (RFC), is involved in sister chromatid cohesion. To examine its relationship with factors involved in DNA replication, we performed a proteomics analysis of Ctf18-interacting proteins. We found that Ctf18 interacts with a replicative DNA polymerase, DNA polymerase ε (pol ε). Co-immunoprecipitation with recombinant Ctf18-RFC and pol ε demonstrated that their binding is direct and mediated by two distinct interactions, one weak and one stable. Three subunits that are specifically required for cohesion in yeast, Ctf18, Dcc1, and Ctf8, formed a trimeric complex (18-1-8) and together enabled stable binding with pol ε. The C-terminal 23-amino acid stretch of Ctf18 was necessary for the trimeric association of 18-1-8 and was required for the stable interaction. The weak interaction was observed with alternative loader complexes including Ctf18-RFC(5), which lacks Dcc1 and Ctf8, suggesting that the common loader structures, including the RFC small subunits (RFC2-5), are responsible for the weak interaction. The two interaction modes, mediated through distinguishable structures of Ctf18-RFC, both occurred through the N-terminal half of pol ε, which includes the catalytic domain. The addition of Ctf18-RFC or Ctf18-RFC(5) to the DNA synthesis reaction caused partial inhibition and stimulation, respectively. Thus, Ctf18-RFC has multiple interactions with pol ε that promote polymorphic modulation of DNA synthesis. We propose that their interaction alters the DNA synthesis mode to enable the replication fork to cooperate with the establishment of cohesion.

  7. Acousto-optical and SAW propagation characteristics of temperature stable multilayered structures based on LiNbO3 and diamond

    International Nuclear Information System (INIS)

    Shandilya, Swati; Sreenivas, K; Gupta, Vinay

    2008-01-01

    Theoretical studies on the surface acoustic wave (SAW) properties of c-axis oriented LiNbO 3 /IDT/diamond and diamond/IDT/128 0 rotated Y-X cut LiNbO 3 multilayered structures have been considered. Both layered structures exhibit a positive temperature coefficient of delay (TCD) characteristic, and a zero TCD device is obtained after integrating with an over-layer of either tellurium dioxide (TeO 2 ) or silicon dioxide (SiO 2 ). The presence of a TeO 2 over-layer enhanced the electromechanical coupling coefficients of both multilayered structures, which acts as a better temperature compensation layer than SiO 2 . The temperature stable TeO 2 /LiNbO 3 /IDT/diamond layered structure exhibits good electromechanical coefficient and higher phase velocity for SAW device applications. On the other hand, a high acousto-optical (AO) figure of merit (30-37) x 10 -15 s 3 kg -1 has been obtained for the temperature stable SiO 2 /diamond/IDT/LiNbO 3 layered structure indicating a promising device structure for AO applications

  8. Stable structures of Al510–800 clusters and lowest energy sequence of truncated octahedral Al clusters up to 10,000 atoms

    International Nuclear Information System (INIS)

    Wu, Xia; He, Chengdong

    2012-01-01

    Highlights: ► The stable structures of Al 510–800 clusters are obtained with the NP-B potential. ► Al 510–800 clusters adopt truncated octahedral (TO) growth pattern based on complete TOs at Al 405 , Al 586 , and Al 711 . ► The lowest energy sequence of complete TOs up to the size 10,000 is proposed. -- Abstract: The stable structures of Al 510–800 clusters are obtained using dynamic lattice searching with constructed cores (DLSc) method by the NP-B potential. According to the structural growth rule, octahedra and truncated octahedra (TO) configurations are adopted as the inner cores in DLSc method. The results show that in the optimized structures two complete TO structures are found at Al 586 and Al 711 . Furthermore, Al 510–800 clusters adopt TO growth pattern on complete TOs at Al 405 , Al 586 , and Al 711 , and the configurations of the surface atoms are investigated. On the other hand, Al clusters with complete TO motifs are studied up to the size 10,000 by the geometrical construction method. The structural characteristics of complete TOs are denoted by the term “family”, and the growth sequence of Al clusters is investigated. The lowest energy sequence of complete TOs is proposed.

  9. Insulin-like growth factor binding proteins: a structural perspective

    Directory of Open Access Journals (Sweden)

    Briony eForbes

    2012-03-01

    Full Text Available Insulin-like growth factor binding proteins (IGFBP-1 to -6 bind insulin-like growth factors-I and -II (IGF-I and IGF-II with high affinity. These binding proteins maintain IGFs in the circulation and direct them to target tissues, where they promote cell growth, proliferation, differentiation and survival via the type 1 IGF receptor (IGF-1R. IGFBPs also interact with many other molecules, which not only influence their modulation of IGF action but also mediate IGF-independent activities that influence processes such as cell migration and apoptosis by influencing gene transcription.IGFBPs-1 to -6 are structurally similar proteins consisting of three distinct domains, N-terminal, Linker and C-terminal. There have been major advances in our understanding of IGFBP structure in the last decade and a half. While there is still no structure of an intact IGFBP to date, several structures of individual N- and C-domains have been solved. The structure of a complex of N-BP-4:IGF-I:C-BP-4 has also been solved, providing a detailed picture of the structural features of the IGF binding site and the mechanism of binding. Structural studies have also identified features important for interaction with extracellular matrix components and integrins. This review summarises structural studies reported so far and highlights features important for binding not only IGF but also other partners. It also highlights future directions in which structural studies will add to our knowledge of the role played by the IGFBP family in normal growth and development, as well as in disease.

  10. Structure of Vibrio cholerae ribosome hibernation promoting factor

    International Nuclear Information System (INIS)

    De Bari, Heather; Berry, Edward A.

    2013-01-01

    The X-ray crystal structure of ribosome hibernation promoting factor from V. cholerae has been determined at 2.0 Å resolution. The crystal was phased by two-wavelength MAD using cocrystallized cobalt. The X-ray crystal structure of ribosome hibernation promoting factor (HPF) from Vibrio cholerae is presented at 2.0 Å resolution. The crystal was phased by two-wavelength MAD using cocrystallized cobalt. The asymmetric unit contained two molecules of HPF linked by four Co atoms. The metal-binding sites observed in the crystal are probably not related to biological function. The structure of HPF has a typical β–α–β–β–β–α fold consistent with previous structures of YfiA and HPF from Escherichia coli. Comparison of the new structure with that of HPF from E. coli bound to the Thermus thermophilus ribosome [Polikanov et al. (2012 ▶), Science, 336, 915–918] shows that no significant structural changes are induced in HPF by binding

  11. Factor Structure of the Conflict Tactics Scale 1

    Directory of Open Access Journals (Sweden)

    Kaori Baba

    2017-07-01

    Full Text Available Background: The Conflict Tactics Scale 1 (CTS1 is a widely used self-report measure of abusive attitudes of parents towards children. The factor structure of the CTS1 still remains to be clarified. The aim of this study was to examine the factor structure of the Japanese version of the CTS1 for postpartum women in community settings. Method: The data in this study came from the Okayama and Kumamoto’s study. These were part of a larger survey using longitudinal questionnaire studies conducted in Japan from 2001 to 2002 and in 2011, respectively. In both study sites, the participant mothers were asked to fill in the CTS1 one month after delivery when they attended for check-up at the out-patient clinic. Results: A total of 1,150 questionnaires were collected, excluding the participants with missing values in the CTS1. Finally, 1,078 were included in the statistical analyses. Data of 1,078 women were divided into two parts. In the first halved sample (n=578, an exploratory factor analysis was conducted for the CTS1 items after exluding nine items with extremely low prevalence. It revealed 2-factor or 3-factor models. Then, we conducted a model comparison with the second halved sample (n=500, using confirmatory factor analysis. In terms of goodness-of-fit indeces, the 2-factor model was superior. Its subscales were Reasoning and Psycholosical Aggression. Conclusion: The 2-factor model of the CTS1 consisting of Reasoning and Psychological Aggression was superior to the 3-factor model. This is not inconsistent with the original authors’ theoretical model.

  12. Stable isotope studies

    International Nuclear Information System (INIS)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  13. Application of Nitrogen and Carbon Stable Isotopes (δ15N and δ13C) to Quantify Food Chain Length and Trophic Structure

    OpenAIRE

    Perkins, Matthew J.; McDonald, Robbie A.; van Veen, F. J. Frank; Kelly, Simon D.; Rees, Gareth; Bearhop, Stuart

    2014-01-01

    Increasingly, stable isotope ratios of nitrogen (δ(15)N) and carbon (δ(13)C) are used to quantify trophic structure, though relatively few studies have tested accuracy of isotopic structural measures. For laboratory-raised and wild-collected plant-invertebrate food chains spanning four trophic levels we estimated nitrogen range (NR) using δ(15)N, and carbon range (CR) using δ(13)C, which are used to quantify food chain length and breadth of trophic resources respectively. Across a range of kn...

  14. Crystal Structure of Human Factor VIII: Implications for the Formation of the Factor IXa-Factor VIIIa Complex

    Energy Technology Data Exchange (ETDEWEB)

    Ngo, J.C.; Huang, M.; Roth, D.A.; Furie, B.C.; Furie, B. (Wyeth); (MBL)

    2008-06-03

    Factor VIII is a procofactor that plays a critical role in blood coagulation, and is missing or defective in hemophilia A. We determined the X-ray crystal structure of B domain-deleted human factor VIII. This protein is composed of five globular domains and contains one Ca{sup 2+} and two Cu{sup 2+} ions. The three homologous A domains form a triangular heterotrimer where the A1 and A3 domains serve as the base and interact with the C2 and C1 domains, respectively. The structurally homologous C1 and C2 domains reveal membrane binding features. Based on biochemical studies, a model of the factor IXa-factor VIIIa complex was constructed by in silico docking. Factor IXa wraps across the side of factor VIII, and an extended interface spans the factor VIII heavy and light chains. This model provides insight into the activation of factor VIII and the interaction of factor VIIIa with factor IXa on the membrane surface.

  15. Crystal Structure of Human Factor VIII: Implications for the Formation of the Factor IXa-Factor VIIIa Complex

    Energy Technology Data Exchange (ETDEWEB)

    Chi Ki Ngo,J.; Huang, M.; Roth, D.; Furie, B.; Furie, B.

    2008-01-01

    Factor VIII is a procofactor that plays a critical role in blood coagulation, and is missing or defective in hemophilia A. We determined the X-ray crystal structure of B domain-deleted human factor VIII. This protein is composed of five globular domains and contains one Ca(2+) and two Cu(2+) ions. The three homologous A domains form a triangular heterotrimer where the A1 and A3 domains serve as the base and interact with the C2 and C1 domains, respectively. The structurally homologous C1 and C2 domains reveal membrane binding features. Based on biochemical studies, a model of the factor IXa-factor VIIIa complex was constructed by in silico docking. Factor IXa wraps across the side of factor VIII, and an extended interface spans the factor VIII heavy and light chains. This model provides insight into the activation of factor VIII and the interaction of factor VIIIa with factor IXa on the membrane surface.

  16. Robust Structure Preserving Nonnegative Matrix Factorization for Dimensionality Reduction

    Directory of Open Access Journals (Sweden)

    Bingfeng Li

    2016-01-01

    Full Text Available As a linear dimensionality reduction method, nonnegative matrix factorization (NMF has been widely used in many fields, such as machine learning and data mining. However, there are still two major drawbacks for NMF: (a NMF can only perform semantic factorization in Euclidean space, and it fails to discover the intrinsic geometrical structure of high-dimensional data distribution. (b NMF suffers from noisy data, which are commonly encountered in real-world applications. To address these issues, in this paper, we present a new robust structure preserving nonnegative matrix factorization (RSPNMF framework. In RSPNMF, a local affinity graph and a distant repulsion graph are constructed to encode the geometrical information, and noisy data influence is alleviated by characterizing the data reconstruction term of NMF with l2,1-norm instead of l2-norm. With incorporation of the local and distant structure preservation regularization term into the robust NMF framework, our algorithm can discover a low-dimensional embedding subspace with the nature of structure preservation. RSPNMF is formulated as an optimization problem and solved by an effective iterative multiplicative update algorithm. Experimental results on some facial image datasets clustering show significant performance improvement of RSPNMF in comparison with the state-of-the-art algorithms.

  17. Discrimination factors of carbon and nitrogen stable isotopes from diet to hair and scat in captive tigers (Panthera tigris) and snow leopards (Uncia uncia).

    Science.gov (United States)

    Montanari, Shaena; Amato, George

    2015-06-15

    In order to use stable isotope ratio values obtained from wild animal tissues, we must accurately calculate the differences in isotope ratios between diet and consumer (δtissue - δdiet). These values, called trophic discrimination factors (TDFs, denoted with ∆), are necessary for stable isotope ecology studies and are best calculated in controlled environments. Scat, hair, and diet samples were collected from captive tigers (n = 8) and snow leopards (n = 10) at the Bronx Zoo. The isotope ratios of carbon and nitrogen, the two most commonly used in ecological studies, of the samples were measured by continuous-flow isotope ratio mass spectrometry. The trophic discrimination factors were calculated for both carbon (δ(13)C values) and nitrogen (δ(15)N values). It was found that the only significant TDFs in this study were diet-hair, ∆(13)CHair, for snow leopards (5.97 ± 1.25‰) and tigers (6.45 ± 0.54‰), and diet-scat, ∆(15)NScat, in snow leopards (2.49 ± 1.30‰). The other mean isotope ratios were not significantly different from that of the premixed feline diet. The ∆(15)NHair values for both species were unusually low, potentially due to the protein content and quality of the feline diet. The discrimination factors of the stable isotopes of carbon and nitrogen calculated in this study can be applied to ecological studies of wild, non-captive terrestrial mammals. The effect of protein quality in isotope discrimination is also worthy of further investigation to better understand variation in TDFs. Carnivore scat is shown to be a valuable material for isotopic analysis. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Diet-tissue discrimination factors and turnover of carbon and nitrogen stable isotopes in tissues of an adult predatory coral reef fish, Plectropomus leopardus.

    Science.gov (United States)

    Matley, J K; Fisk, A T; Tobin, A J; Heupel, M R; Simpfendorfer, C A

    2016-01-15

    Stable isotope ratios (δ(13)C and δ(15)N values) provide a unique perspective into the ecology of animals because the isotope ratio values of consumers reflect the values in food. Despite the value of stable isotopes in ecological studies, the lack of species-specific experimentally derived diet-tissue discrimination factors (DTDFs) and turnover rates limits their application at a broad scale. Furthermore, most aquatic feeding experiments use temperate, fast-growing fish species and few have considered medium- to large-sized adults with low growth rates from tropical ecosystems. A controlled-diet stable isotope feeding trial was conducted over a 196-day period for the adult predatory reef fish leopard coralgrouper (Plectropomus leopardus). This study calculated δ(13)C and δ(15)N DTDFs and turnover rates in five tissues (liver, plasma, red blood cells (RBC), fin, and muscle) using a continuous flow isotope ratio mass spectrometer equipped with an elemental analyzer. In addition, the effect of chemical lipid extraction (LE) on stable isotope values was examined for each tissue. Turnover was mainly influenced by metabolism (as opposed to growth) with LE δ(15)N half-life values lowest in fin (37 days) and plasma (66 days), and highest in RBC (88 days) and muscle (126 days). The diet-tissue discrimination factors for δ(15)N values in all tissues (Δ(15)N: -0.15 to 1.84‰) were typically lower than commonly reported literature values. Lipid extraction altered both δ(15) N and δ(13)C values compared with untreated samples; however, for the δ(15)N values, the differences were small (mean δ(15)N(LE-Bulk) stable isotope data for medium- to large-sized fish and demonstrates that DTDFs developed for temperate fish species, particularly for δ(15)N values, may not apply to tropical species. Sampling of muscle and/or RBC is recommended for a relatively long-term representation of feeding habits, while plasma and/or fin should be used for a more recent indication of

  19. A randomized study of coconut oil versus sunflower oil on cardiovascular risk factors in patients with stable coronary heart disease

    Directory of Open Access Journals (Sweden)

    Maniyal Vijayakumar

    2016-07-01

    Conclusion: Coconut oil even though rich in saturated fatty acids in comparison to sunflower oil when used as cooking oil media over a period of 2 years did not change the lipid-related cardiovascular risk factors and events in those receiving standard medical care.

  20. Synthesis and characterization of highly efficient and stable Pr6O11/Ag3PO4/Pt ternary hybrid structure

    International Nuclear Information System (INIS)

    Deng, Jiatao; Liu, Lin; Niu, Tongjun; Sun, Xiaosong

    2017-01-01

    Highlights: • Visible-light-driven Pr 6 O 11 /Ag 3 PO 4 /Pt photocatalysts were prepared. • Pr 6 O 11 /Ag 3 PO 4 /Pt showed highly efficient and stable photocatalystic activity. • The photocatalytic mechanism of Pr 6 O 11 /Ag 3 PO 4 /Pt composite was given. - Abstract: Ag 3 PO 4 is an excellent photocatalyst with high efficiency and quantum yield, but suffers from the fast recombination of photogenerated electron-hole pairs and photo-corrosion. Hereby, the highly efficient and stable visible-light-driven Pr 6 O 11 /Ag 3 PO 4 /Pt photocatalyst were prepared via a three-step wet chemical approach. The as-prepared Pr 6 O 11 /Ag 3 PO 4 /Pt composite was characterized by X-ray diffraction, US-vis diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, photoluminescence spectra and transient photocurrent as well. Comparing with single Pr 6 O 11 or Ag 3 PO 4 , the prepared Pr 6 O 11 /Ag 3 PO 4 /Pt composite exhibited much higher photocatalytic activity and stability for the degradation of Rhodamine B under visible light irradiation (>420 nm). The enhanced photocatalytic performance of Pr 6 O 11 /Ag 3 PO 4 /Pt composite has been attributed to the efficient separation of photo-generated electron-hole pairs through a scheme system composed of Pr 6 O 11, Ag 3 PO 4 and Pt.

  1. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1994-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets, with a few more additions - with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers - exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the foree of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc. (orig.)

  2. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1993-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc

  3. Factor structure and risk factors for the health status of homeless veterans.

    Science.gov (United States)

    Goldstein, Gerald; Luther, James F; Haas, Gretchen L; Appelt, Cathleen J; Gordon, Adam J

    2010-12-01

    Homeless veterans have numerous health problems that have been previously characterized as falling into four major subgroups; addiction, psychosis, vascular disorders, and generalized medical and psychiatric illness. Comorbid conditions are common, often involving a combination of psychiatric and medical disorders. Using data from the same survey of homeless veterans that was used to establish these subgroups with cluster analysis, the present study examined the structure of these subgroup patterns through the use of factor analysis. This analysis yielded a five factor solution. They were named "Cardiac", Mood, Stress, Addiction, and Psychosis factors. Factor scores were computed and an odds ratio analysis was accomplished to determine the association between obtaining a high score on a given factor with a number of sociodemographic and homelessness related variables. It was concluded that health status of homeless veterans is a complex condition, but has a clear latent structure demonstrated by factor analysis. Scoring high or low on a particular factor is associated with numerous historical and sociodemographic considerations, notably age, ethnicity, and employment status.

  4. Role of thermodynamic, kinetic and structural factors in the recrystallization behavior of amorphous erythromycin salts

    Energy Technology Data Exchange (ETDEWEB)

    Nanakwani, Kapil; Modi, Sameer R.; Kumar, Lokesh; Bansal, Arvind K., E-mail: akbansal@niper.ac.in

    2014-04-01

    Graphical abstract: - Highlights: • Crystallization kinetics of amorphous erythromycin salts was assessed. • Contribution of thermodynamic, kinetic and structural factors was evaluated. • Role of counterions on physical stability of amorphous salts was investigated. • Implications of the study: In rationalizing stabilization approach for amorphous form. - Abstract: Amorphous form has become an important drug delivery strategy for poorly water soluble drugs. However, amorphous form has inherent physical instability due to its tendency to recrystallize to stable crystalline form. In the present study, amorphous forms of erythromycin free base (ED) and its salts namely, stearate (ES), phosphate (EP) and thiocyanate (ET) were generated by in situ melt quenching and evaluated for their crystallization tendency. Salts were characterized for kinetic, thermodynamic and structural factors to understand crystallization behavior. Kinetics of crystallization followed the order as ES > EP > ET > ED. Fragility and molecular mobility does not completely explain these findings. However, configurational entropy (S{sub conf}), indicative of entropic barrier to crystallization, followed the order as ET > EP > ES > ED. Lower crystallization tendency of ED can be explained by its lower thermodynamic driving force for crystallization (H{sub conf}). This correlated well with different structural parameters for the counter ions.

  5. Relationship between tolerance factor and temperature coefficient of permittivity of temperature-stable high permittivity BaTiO3–Bi(MeO3 compounds

    Directory of Open Access Journals (Sweden)

    Natthaphon Raengthon

    2016-03-01

    Full Text Available The temperature coefficient of permittivity (TCε of BaTiO3–Bi(MeO3 solid solutions were investigated. It was determined that as the tolerance factor was decreased with the addition of Bi(MeO3, the TCε shifted from large negative values to TCε values approaching zero. It is proposed that the different bonding nature of the dopant cation affects the magnitude and temperature stability of the permittivity. This study suggests that the relationship between tolerance factor and TCε can be used as a guide to design new dielectric compounds exhibiting temperature-stable high permittivity characteristics, which is similar to past research on perovskite and pyrochlore-based microwave dielectrics.

  6. Magnetic field effects on charge structure factors of gapped graphene structure

    Science.gov (United States)

    Rezania, Hamed; Tawoose, Nasrin

    2018-02-01

    We present the behaviors of dynamical and static charge susceptibilities of undoped gapped graphene using the Green's function approach in the context of tight binding model Hamiltonian. Specially, the effects of magnetic field on the plasmon modes of gapped graphene structure are investigated via calculating correlation function of charge density operators. Our results show the increase of magnetic field leads to disappear high frequency plasmon mode for gapped case. We also show that low frequency plasmon mode has not affected by increase of magnetic field and chemical potential. Finally the temperature dependence of static charge structure factor of gapp graphene structure is studied. The effects of both magnetic field and gap parameter on the static structure factor are discusses in details.

  7. Buckling control of morphing composite airfoil structure using multi-stable laminate by piezoelectric sensors/actuators

    Science.gov (United States)

    Zareie, Shahin; Zabihollah, Abolghassem; Azizi, Aydin

    2011-04-01

    In the present work, an unsymmetric laminated plate with surface bonded piezoelectric sensors, and actuators has been considered. Piezoelectric sensor were used to monitor the load and deformation bifurcation occurs. Monitoring the shape and load of a morphing structure is essential to ascertain that the structure is properly deployed and it is not loaded excessively ,thus, preventing structural to failure. A piezoceramic actuator is used to provide activation load and to force the structure to change its stability state from one to another. A non-linear finite element model based on the layerwise displacement theory considering the electro-mechanical coupling effects of piezoelectric elements has been developed for simulation purposes. A control mechanism is also employed to actively control the shape of the structure. It is observed that, utilizing multistable composite to design a morphing structure may significantly reduce the energy required for changing the shape. Further controlling the buckling phenomena using piezoelectric sensor and actuator along with an ON/OFF controller can effectively and efficiency enhance the performance of the morphing structure during manoeuver.

  8. Employee motivation in Ghana: A factor structure and measurement tool

    Directory of Open Access Journals (Sweden)

    B. B. Puplampu

    2007-12-01

    Full Text Available Purpose: This paper reports research on the factor structure of employee motivation as well as provides a tool for measuring the level of employee motivation in Ghanaian organisations. Methodology: The study was designed as exploratory, comparative and cross-sectional. 260 respondents drawn from across the gender, status and job grade hierarchy of 19 organisations participated. The organisations were matched in terms of tenure (over 5years, number of employees (50 or more and geographic location (headquartered in Accra. A 41-item questionnaire on the Level of Motivation (LoM; Characteristics of Employee Motivation (CEM; aspects of Organisational Citizenship Behaviour (OCB; Managerial Assumptions about employee behaviour (MA; Contextual Institutional Analysis (IAN and Organisational Leadership Issues (Le was developed and used. The instrument combined fixed response format on a 3-point scale with open-ended responses. Findings: Exploratory Factor Analyses (Varimax Rotation, converging in 26 iterations yielded 6 factors, which account for 60% of the variance. Thematic analyses of both interview and open-ended questionnaire data support the emergent factor structure, providing some tentative indication that employee motivation in the Ghanaian (or indeed African context should be looked at more in an integrated manner rather than in terms of the limiting confines of any one theory of motivation. The 3 items hypothesised to constitute the measure of level of employee motivation loaded neatly onto Factor 6. One-way ANOVA demonstrated no differences in the level of motivation across the organisational samples; this was confirmed by the interview data. Implications/Originality/Value: The implications and value of this research are: that motivation research in Africa does need to focus more on developing an integrated model of employee motivation; also, a simple 3-item but novel tool for measuring the level of employee motivation as well as its

  9. The Pediatric Eating Assessment Tool: Factor Structure and Psychometric Properties.

    Science.gov (United States)

    Thoyre, Suzanne M; Pados, Britt F; Park, Jinhee; Estrem, Hayley; McComish, Cara; Hodges, Eric A

    2018-02-01

    The Pediatric Eating Assessment Tool (PediEAT) is a parent-report instrument developed to assess symptoms of feeding problems in children aged 6 months to 7 years. The purpose of this study was to identify the factor structure of the PediEAT and test its psychometric properties, including internal consistency reliability, temporal stability, and construct validity. Participants included 567 parents of children aged 6 months to 7 years. Fifty-four percent of the sample had parent report of a diagnosed feeding problem or feeding concerns. Exploratory factor-analysis techniques were used to remove redundant or non-endorsed items and identify the factor structure of the instrument. Construct validity was examined with 466 parents completing the Mealtime Behavior Questionnaire as a criterion standard. Known-groups validation was used to compare PediEAT scores between children with and without diagnosed feeding problems. Temporal stability of the PediEAT was examined with 97 parents repeating the PediEAT after 2 weeks. Principal components factor analysis with varimax rotation supported a 4-factor model accounting for 39.4% of the total variance. The 4 subscales (Physiologic Symptoms, Problematic Mealtime Behaviors, Selective/Restrictive Eating, Oral Processing) demonstrated acceptable internal consistencies (coefficient alphas: 0.92, 0.91, 0.83, 0.83; respectively). Construct validity was supported in 2 ways. The PediEAT correlated with the Mealtime Behavior Questionnaire (r = 0.77, P < 0.001) and total score and subscale scores were significantly different between children with and without diagnosed feeding problem (P < 0.001). Temporal stability was demonstrated through test-retest reliability (r = 0.95, P < 0.001). Strong psychometric properties support the use of the PediEAT in research and clinical practice.

  10. Metacognition Assessment Interview: Instrument description and factor structure

    Directory of Open Access Journals (Sweden)

    Giovanni Pellecchia

    2015-12-01

    Full Text Available Objective: Metacognition is a multi-component psychological construct, characterised by the ability to identify and describe one’s own mental states and those of others. Evidence has been found for an association between deficits in metacognitive abilities and poor social functioning, low quality of life, psychopathology, and symptoms in Personality Disorders (PDs. However, to date, there are few psychometrically validated instruments available for assessing the different components of metacognition. A semi-structured interview, the Metacognition Assessment Interview (MAI, has been developed to evaluate different domains of metacognition. In the present study, we investigated the psychometric properties of the MAI in an outpatient clinical sample. Method: The MAI was administered to a clinical population of 306 outpatients attending a private clinical centre. Exploratory factor analysis, confirmatory factor analysis and correlation with instruments assessing alexithymia and interpersonal problems were carried out to examine the dimensionality and validity of the MAI. Result: Explorative and confirmatory factor analyses revealed a good fit for both a two-factor model and a four-factor model of metacognition. The two-factor model yielded two main dimensions, which we named: Self domain, defined as self-reflection, and Other domain, defined as critical distancing from one’s own mental state and that of others. The four-factor solution is composed of four sub-domains: monitoring, integration, differentiation and decentration. Moreover, the MAI showed good convergent validity, with significant correlations with both alexithymia and interpersonal problems. Conclusions: These results confirm that the MAI is a reliable instrument for measuring metacognition and its different sub-domains. In particular, the MAI represents a useful and flexible instrument for the assessment of metacognition impairments in different psychopathologies and it can provide

  11. Structural factors affecting prosthodontic decision making in Japan

    Directory of Open Access Journals (Sweden)

    Noriyuki Wakabayashi

    2015-11-01

    Full Text Available Prosthodontic treatment strategies, prosthetic designs and materials, and treatment procedures are not determined solely by the diagnosis. We discuss the major effect of structural factors surrounding prosthodontic care on treatment decisions in Japan. These structural factors are related to the dentist, such as the dentist's education, postgraduate courses, and access to the latest research, and to the health care support system, including the social insurance system. Education content from schools of dentistry has clear effects on dentists’ treatment decisions, and the specific modalities taught depend highly on the school faculty. The use of research, especially clinical studies, in treatment decisions is currently limited. Regarding the health care support system factors, the public health insurance system has a strong effect on the actual prosthodontic treatments performed in Japan. To maintain the current piecework payment system, efforts should be encouraged to preclude both overtreatment and undertreatment. New perspectives on treatment decisions associated with technological advancement and changes in health care needs should be established to ensure that the Japanese population can enjoy high-quality prosthodontic treatment that meets international standards. The development of a clinical pathway and decision-making model that adheres to academic-based clinical guidelines and the insurance system will be necessary.

  12. INVESTIGATING THE FACTOR STRUCTURE OF THE BLOG ATTITUDE SCALE

    Directory of Open Access Journals (Sweden)

    Zahra SHAHSAVAR

    2010-10-01

    Full Text Available Due to the wide application of advanced technology in education, many attitude scales have been developed to evaluate learners’ attitudes toward educational tools. However, with the rapid development of emerging technologies, using blogs as one of the Web 2.0 tools is still in its infancy and few blog attitude scales have been developed yet. In view of this need, a lot of researchers like to design a new scale based on their conceptual and theoretical framework of their own study rather than using available scales. The present study reports the design and development of a blog attitude scale (BAS. The researchers developed a pool of items to capture the complexity of the blog attitude trait, selected 29 items in the content analysis, and assigned the scale comprising 29 items to 216 undergraduate students to explore the underlying structure of the BAS. In exploratory factor analysis, three factors were discovered: blog anxiety, blog desirability, and blog self-efficacy; 14 items were excluded. The extracted items were subjected to a confirmatory factor analysis which lent further support to the BAS underpinning structure.

  13. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  14. Thermally Stable and Electrically Conductive, Vertically Aligned Carbon Nanotube/Silicon Infiltrated Composite Structures for High-Temperature Electrodes.

    Science.gov (United States)

    Zou, Qi Ming; Deng, Lei Min; Li, Da Wei; Zhou, Yun Shen; Golgir, Hossein Rabiee; Keramatnejad, Kamran; Fan, Li Sha; Jiang, Lan; Silvain, Jean-Francois; Lu, Yong Feng

    2017-10-25

    Traditional ceramic-based, high-temperature electrode materials (e.g., lanthanum chromate) are severely limited due to their conditional electrical conductivity and poor stability under harsh circumstances. Advanced composite structures based on vertically aligned carbon nanotubes (VACNTs) and high-temperature ceramics are expected to address this grand challenge, in which ceramic serves as a shielding layer protecting the VACNTs from the oxidation and erosive environment, while the VACNTs work as a conductor. However, it is still a great challenge to fabricate VACNT/ceramic composite structures due to the limited diffusion of ceramics inside the VACNT arrays. In this work, we report on the controllable fabrication of infiltrated (and noninfiltrated) VACNT/silicon composite structures via thermal chemical vapor deposition (CVD) [and laser-assisted CVD]. In laser-assisted CVD, low-crystalline silicon (Si) was quickly deposited at the VACNT subsurfaces/surfaces followed by the formation of high-crystalline Si layers, thus resulting in noninfiltrated composite structures. Unlike laser-assisted CVD, thermal CVD activated the precursors inside and outside the VACNTs simultaneously, which realized uniform infiltrated VACNT/Si composite structures. The growth mechanisms for infiltrated and noninfiltrated VACNT/ceramic composites, which we attributed to the different temperature distributions and gas diffusion mechanism in VACNTs, were investigated. More importantly, the as-farbicated composite structures exhibited excellent multifunctional properties, such as excellent antioxidative ability (up to 1100 °C), high thermal stability (up to 1400 °C), good high velocity hot gas erosion resistance, and good electrical conductivity (∼8.95 Sm -1 at 823 K). The work presented here brings a simple, new approach to the fabrication of advanced composite structures for hot electrode applications.

  15. Evolution of potent and stable placental-growth-factor-1-targeting CovX-bodies from phage display peptide discovery.

    Science.gov (United States)

    Bower, Kristen E; Lam, Son N; Oates, Bryan D; Del Rosario, Joselyn R; Corner, Emily; Osothprarop, Trina F; Kinhikar, Arvind G; Hoye, Julie A; Preston, R Ryan; Murphy, Robert E; Campbell, Lioudmila A; Huang, Hanhua; Jimenez, Judith; Cao, Xia; Chen, Gang; Ainekulu, Zemeda W; Datt, Aakash B; Levin, Nancy J; Doppalapudi, Venkata R; Pirie-Shepherd, Steven R; Bradshaw, Curt; Woodnutt, Gary; Lappe, Rodney W

    2011-03-10

    Novel phage-derived peptides are the first reported molecules specifically targeting human placental growth factor 1 (PlGF-1). Phage data enabled peptide modifications that decreased IC(50) values in PlGF-1/VEGFR-1 competition ELISA from 100 to 1 μM. Peptides exhibiting enhanced potency were bioconjugated to the CovX antibody scaffold 1 (CVX-2000), generating bivalent CovX-Bodies with 2 nM K(D) against PlGF-1. In vitro and in vivo peptide cleavage mapping studies enabled the identification of proteolytic hotspots that were subsequently chemically modified. These changes decreased IC(50) to 0.4 nM and increased compound stability from 5% remaining at 6 h after injection to 35% remaining at 24 h with a β phase half-life of 75 h in mice. In cynomolgus monkey, a 78 h β half-life was observed for lead compound 2. The pharmacological properties of 2 are currently being explored.

  16. An Empirical Examination of the Relationship Between Test Factor Structure and Test Hierarchical Structure.

    Science.gov (United States)

    Bart, William M.; Airasian, Peter W.

    The question of whether test factor structure is indicative of the test item hierarchy was examined. Data from 1,000 subjects on two sets of five bivalued Law School Admission Test items, which were analyzed with latent trait methods of Bock and Lieberman and of Christoffersson in Psychometrika, were analyzed with an ordering-theoretic method to…

  17. 2,6,10-Tris(dialkylamino)trioxatriangulenium ions. Synthesis, structure, and properties of exceptionally stable carbenium ions

    DEFF Research Database (Denmark)

    Laursen, B.W.; Krebs, Frederik C; Nielsen, M.F.

    1998-01-01

    A general synthetic route to a novel type of triamino-substituted planar carbenium ions (5) is reported. The synthetic method is based on a facile and selective nucleophilic aromatic substitution on the 4,6-trimethoxyphenyl)carbenium ion (1) with amines and gives access to a wide variety of more...... complex amino-substituted carbenium ions. X-ray crystallography shows that the cis(N-pyrrolidinyl)-4,8,12-trioxatriangulenium ion (5b) is planar and forms segregated stacks of cations and PF6 anions in the solid phase. The stability of the 2,6, 0-tris(diethylamino)- 4,8,12-trioxatriangulenium ion 5a...... is expressed as the pK(R+) value, which is determined in strongly basic nonaqueous solution on-the basis of a new acidity function C-. The pK(R+) value of 5a is measured to be 19.7, which is 10 orders of magnitude higher than the values found for the most stable carbenium ions previously reported...

  18. Factors influencing efficient structure of fuel and energy complex

    Science.gov (United States)

    Sidorova, N. G.; Novikova, S. A.

    2017-10-01

    The development of the Russian fuel-energy complex is a priority for the national economic policy, and the Far East is a link between Russia and the Asia-Pacific region. Large-scale engineering of numerous resources of the Far East will force industrial development, increase living standard and strengthen Russia’s position in the global energy market. So, revealing the factors which influence rational structure of the fuel-energy complex is very urgent nowadays. With the use of depth analysis of development tendencies of the complex and its problems the authors show ways of its efficiency improvement.

  19. Partial structure factors in star polymer/colloid mixtures

    CERN Document Server

    Stellbrink, J; Richter, D; Moussaid, A; Schofield, A B; Poon, W C K; Pusey, P N; Lindner, P; Dzubiella, J; Likos, C N; Löwen, H

    2002-01-01

    Addition of polymer to colloidal suspensions induces an attractive part to the colloid pair potential, which is of purely entropic origin (''depletion interaction''). We investigated the influence of polymer branching on depletion forces by studying mixtures of hard sphere colloids and star polymers with increasing arm number f=2-32, but constant R sub g approx 500 A. We found a pronounced effect of branching on the position of the gas/liquid demixing transition. Using small angle neutron scattering (SANS) we were able to measure partial structure factors in star polymer/colloid mixtures. The relative distance to the demixing transition is reflected in our scattering data. (orig.)

  20. More Stable Ties or Better Structure? An Examination of the Impact of Co-author Network on Team Knowledge Creation

    Directory of Open Access Journals (Sweden)

    Mingze Li

    2017-09-01

    Full Text Available This study aims to explore the influence of co-author network on team knowledge creation. Integrating the two traditional perspectives of network relationship and network structure, we examine the direct and interactive effects of tie stability and structural holes on team knowledge creation. Tracking scientific articles published by 111 scholars in the research field of human resource management from the top 8 American universities, we analyze scholars’ scientific co-author networks. The result indicates that tie stability changes the teams’ information processing modes and, when graphed, results in an inverted U-shape relationship between tie stability and team knowledge creation. Moreover, structural holes in co-author network are proved to be harmful to team knowledge sharing and diffusion, thereby impeding team knowledge creation. Also, tie stability and structural hole interactively influence team knowledge creation. When the number of structural hole is low in the co-author network, the graphical representation of the relationship between tie stability and team knowledge creation tends to be a more distinct U-shape.

  1. The use of protein structure/activity relationships in the rational design of stable particulate delivery systems

    Directory of Open Access Journals (Sweden)

    M.H.B. Costa

    2002-06-01

    Full Text Available The recombinant heat shock protein (18 kDa-hsp from Mycobacterium leprae was studied as a T-epitope model for vaccine development. We present a structural analysis of the stability of recombinant 18 kDa-hsp during different processing steps. Circular dichroism and ELISA were used to monitor protein structure after thermal stress, lyophilization and chemical modification. We observed that the 18 kDa-hsp is extremely resistant to a wide range of temperatures (60% of activity is retained at 80ºC for 20 min. N-Acylation increased its ordered structure by 4% and decreased its ß-T1 structure by 2%. ELISA demonstrated that the native conformation of the 18 kDa-hsp was preserved after hydrophobic modification by acylation. The recombinant 18 kDa-hsp resists to a wide range of temperatures and chemical modifications without loss of its main characteristic, which is to be a source of T epitopes. This resistance is probably directly related to its lack of organization at the level of tertiary and secondary structures.

  2. Cloud immersion building shielding factors for US residential structures.

    Science.gov (United States)

    Dickson, E D; Hamby, D M

    2014-12-01

    This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario within a semi-infinite cloud of radioactive material. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement, as well for single-wide manufactured housing-units.

  3. Validity and factor structure of the bodybuilding dependence scale.

    Science.gov (United States)

    Smith, D; Hale, B

    2004-04-01

    To investigate the factor structure, validity, and reliability of the bodybuilding dependence scale and to investigate differences in bodybuilding dependence between men and women and competitive and non-competitive bodybuilders. Seventy two male competitive bodybuilders, 63 female competitive bodybuilders, 87 male non-competitive bodybuilders, and 63 non-competitive female bodybuilders completed the bodybuilding dependence scale (BDS), the exercise dependence questionnaire (EDQ), and the muscle dysmorphia inventory (MDI). Confirmatory factor analysis of the BDS supported a three factor model of bodybuilding dependence, consisting of social dependence, training dependence, and mastery dependence (Q = 3.16, CFI = 0.98, SRMR = 0.04). Internal reliability of all three subscales was high (Cronbach's alpha = 0.92, 0.92, and 0.93 respectively). Significant (pbodybuilders scored significantly (pbodybuilders. However, there were no significant sex differences on any of the BDS subscales (p>0.05). The three factor BDS appears to be a reliable and valid measure of bodybuilding dependence. Symptoms of bodybuilding dependence are more prevalent in competitive bodybuilders than non-competitive ones, but there are no significant sex differences in bodybuilding dependence.

  4. UCLA Loneliness Scale (Version 3): reliability, validity, and factor structure.

    Science.gov (United States)

    Russell, D W

    1996-02-01

    In this article I evaluated the psychometric properties of the UCLA Loneliness Scale (Version 3). Using data from prior studies of college students, nurses, teachers, and the elderly, analyses of the reliability, validity, and factor structure of this new version of the UCLA Loneliness Scale were conducted. Results indicated that the measure was highly reliable, both in terms of internal consistency (coefficient alpha ranging from .89 to .94) and test-retest reliability over a 1-year period (r = .73). Convergent validity for the scale was indicated by significant correlations with other measures of loneliness. Construct validity was supported by significant relations with measures of the adequacy of the individual's interpersonal relationships, and by correlations between loneliness and measures of health and well-being. Confirmatory factor analyses indicated that a model incorporating a global bipolar loneliness factor along with two method factor reflecting direction of item wording provided a very good fit to the data across samples. Implications of these results for future measurement research on loneliness are discussed.

  5. Local and regional factors influence the structure of treehole metacommunities

    Directory of Open Access Journals (Sweden)

    Kegan Benjamin

    2008-12-01

    Full Text Available Abstract Background Abiotic and biotic factors in a local habitat may strongly impact the community residing within, but spatially structured metacommunities are also influenced by regional factors such as immigration and colonization. We used three years of monthly treehole census data to evaluate the relative influence of local and regional factors on our study system. Results Every species responded to at least one of three local environmental factors measured: water volume, leaf litter mass, and presence of a top predator. Several species were affected by water volume, and a non-exclusive group of species were influenced by leaf litter mass. Relative abundance of Aedes triseriatus was higher in treeholes with higher volumes of water, and relative abundances of three out of six other species were lower in treeholes with higher volumes of water. Leaf litter mass positively affected densities of Aedes triseriatus and relative abundance of several dipteran species. The density of the top predator, Toxorhynchites rutilus, affected the relative abundance of the two most common species, A. triseriatus and Culicoides guttipennis. Treeholes with T. rutilus had an average of two more species than treeholes without T. rutilus. We found little evidence of synchrony between pairs of treeholes, either spatially or temporally. There were high levels of spatial and temporal turnover, and spatial turnover increased with distance between patches. Conclusion The strong effects of water volume, leaf litter mass, and presence of a top predator, along with the high temporal turnover strongly suggest that species presence and density are determined by local factors and changes in those factors over time. Both low water volume and high predator densities can eliminate populations in local patches, and those populations can recolonize patches when rain refills or predators exit treeholes. Population densities of the same species were not matched between pairs of

  6. Local and regional factors influence the structure of treehole metacommunities

    Science.gov (United States)

    Paradise, Christopher J; Blue, Jarrod D; Burkhart, John Q; Goldberg, Justin; Harshaw, Lauren; Hawkins, Katherine D; Kegan, Benjamin; Krentz, Tyler; Smith, Leslie; Villalpando, Shawn

    2008-01-01

    Background Abiotic and biotic factors in a local habitat may strongly impact the community residing within, but spatially structured metacommunities are also influenced by regional factors such as immigration and colonization. We used three years of monthly treehole census data to evaluate the relative influence of local and regional factors on our study system. Results Every species responded to at least one of three local environmental factors measured: water volume, leaf litter mass, and presence of a top predator. Several species were affected by water volume, and a non-exclusive group of species were influenced by leaf litter mass. Relative abundance of Aedes triseriatus was higher in treeholes with higher volumes of water, and relative abundances of three out of six other species were lower in treeholes with higher volumes of water. Leaf litter mass positively affected densities of Aedes triseriatus and relative abundance of several dipteran species. The density of the top predator, Toxorhynchites rutilus, affected the relative abundance of the two most common species, A. triseriatus and Culicoides guttipennis. Treeholes with T. rutilus had an average of two more species than treeholes without T. rutilus. We found little evidence of synchrony between pairs of treeholes, either spatially or temporally. There were high levels of spatial and temporal turnover, and spatial turnover increased with distance between patches. Conclusion The strong effects of water volume, leaf litter mass, and presence of a top predator, along with the high temporal turnover strongly suggest that species presence and density are determined by local factors and changes in those factors over time. Both low water volume and high predator densities can eliminate populations in local patches, and those populations can recolonize patches when rain refills or predators exit treeholes. Population densities of the same species were not matched between pairs of treeholes, suggesting variation

  7. The stable repression of mesenchymal program is required for hepatocyte identity: a novel role for hepatocyte nuclear factor 4α.

    Science.gov (United States)

    Santangelo, Laura; Marchetti, Alessandra; Cicchini, Carla; Conigliaro, Alice; Conti, Beatrice; Mancone, Carmine; Bonzo, Jessica A; Gonzalez, Frank J; Alonzi, Tonino; Amicone, Laura; Tripodi, Marco

    2011-06-01

    The concept that cellular terminal differentiation is stably maintained once development is complete has been questioned by numerous observations showing that differentiated epithelium may undergo an epithelial-to-mesenchymal transition (EMT) program. EMT and the reverse process, mesenchymal-to-epithelial transition (MET), are typical events of development, tissue repair, and tumor progression. In this study, we aimed to clarify the molecular mechanisms underlying these phenotypic conversions in hepatocytes. Hepatocyte nuclear factor 4α (HNF4α) was overexpressed in different hepatocyte cell lines and the resulting gene expression profile was determined by real-time quantitative polymerase chain reaction. HNF4α recruitment on promoters of both mesenchymal and EMT regulator genes was determined by way of electrophoretic mobility shift assay and chromatin immunoprecipitation. The effect of HNF4α depletion was assessed in silenced cells and in the context of the whole liver of HNF4 knockout animals. Our results identified key EMT regulators and mesenchymal genes as new targets of HNF4α. HNF4α, in cooperation with its target HNF1α, directly inhibits transcription of the EMT master regulatory genes Snail, Slug, and HMGA2 and of several mesenchymal markers. HNF4α-mediated repression of EMT genes induces MET in hepatomas, and its silencing triggers the mesenchymal program in differentiated hepatocytes both in cell culture and in the whole liver. The pivotal role of HNF4α in the induction and maintenance of hepatocyte differentiation should also be ascribed to its capacity to continuously repress the mesenchymal program; thus, both HNF4α activator and repressor functions are necessary for the identity of hepatocytes. Copyright © 2011 American Association for the Study of Liver Diseases.

  8. Stable loop in the crystal structure of the intercalated four-stranded cytosine-rich metazoan telomere

    Science.gov (United States)

    Kang, C.; Berger, I.; Lockshin, C.; Ratliff, R.; Moyzis, R.; Rich, A.

    1995-01-01

    In most metazoans, the telomeric cytosine-rich strand repeating sequence is d(TAACCC). The crystal structure of this sequence was solved to 1.9-A resolution. Four strands associate via the cytosine-containing parts to form a four-stranded intercalated structure held together by C.C+ hydrogen bonds. The base-paired strands are parallel to each other, and the two duplexes are intercalated into each other in opposite orientations. One TAA end forms a highly stabilized loop with the 5' thymine Hoogsteen-base-paired to the third adenine. The 5' end of this loop is in close proximity to the 3' end of one of the other intercalated cytosine strands. Instead of being entirely in a DNA duplex, this structure suggests the possibility of an alternative conformation for the cytosine-rich telomere strands.

  9. Facile synthesis of stable structured MoS{sub 2}-Mo-CNFs heteroarchitecture with enhanced hydrogen evolution

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Qionghua [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Faculty of Material and Energy, South West University, Chongqing 400700 (China); Yao, Yucen [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Liu, Bitao, E-mail: liubitao007@163.com [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Peng, Lingling; Yan, Hengqing; Hou, Zhupei; Wang, Jun [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Lin, Yue, E-mail: linyue@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026 (China)

    2017-06-01

    3D structured MoS{sub 2} are grown in-situ on Mo particles embedded carbon nanofibers (CNFs) via a hydrothermal method. Due to this special structure, the bonding and effective electron delivery between CNFs and MoS{sub 2} are both enhanced, and which will exhibits a better hydrogen evolution activity. The onset potential of this MoS{sub 2}-Mo-CNFs catalyst will decreased to 60 mV compared to the 90 mV for the MoS{sub 2}-CNFs. And its current density nearly no change with 5000 cycles which is better than the 32.3% decrease of MoS{sub 2}-CNFs at η = 300 mV (V vs RHE). - Highlights: • Newly structured MoS{sub 2}-Mo-CNFs with effectively connection between MoS{sub 2} and CNFs successfully synthesized. • This structure can enhance the charge transfer and significantly increase electrocatalytic efficiency. • Nearly no HER activity loss after 5000 CV cycles.

  10. Microbial food web mapping: linking carbon cycling and community structure in soils through pyrosequencing enabled stable isotope probing

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, Daniel H. [Cornell Univ., Ithaca, NY (United States)

    2015-03-15

    Soil represents a massive reservoir of active carbon and climate models vary dramatically in predicting how this carbon will respond to climate change over the coming century. A major cause of uncertainty is that we still have a very limited understand the microorganisms that dominate the soil carbon cycle. The vast majority of soil microbes cannot be cultivated in the laboratory and the diversity of organisms and enzymes that participate in the carbon cycle is staggeringly complex. We have developed a new toolbox for exploring the carbon cycle and the metabolic and ecological characteristics of uncultivated microorganisms. The high-resolution nucleic acid stable isotope probing approach that we have developed makes it possible to characterize microbial carbon cycling dynamics in soil. The approach allows us to track multiple 13C-labeled substrates into thousands of microbial taxa over time. Using this approach we have discovered several major lineages of uncultivated microorganisms that participate in cellulose metabolism and are found widely in soils (including Verrucomicrobia and Chloroflexi, which have not previously been implicated as major players in the soil carbon cycle). Furthermore, isotopic labelling of nucleic acids enables community genomics and permits genome fragment binning for a majority of these cellulolytic microorganisms allowing us to explore the metabolic underpinnings of cellulose degradation. This approach has allowed us to describe unexpected dynamics of carbon metabolism with different microbial taxa exhibiting characteristic patterns of carbon substrate incorporation, indicative of distinct ecological strategies. The data we describe allows us to characterize the activity of novel microorganisms as they occur in the environment and these data provide a basis for understanding how the physiological traits of discrete microorganisms sum to govern the complex responses of the soil carbon cycle.

  11. Feeding ecology and phylogenetic structure of a complex neotropical termite assemblage, revealed by nitrogen stable isotope ratios

    Czech Academy of Sciences Publication Activity Database

    Bourguignon, T.; Šobotník, Jan; Lepoint, G.; Martin, J. M.; Hardy, O. J.; Dejean, A.; Roisin, Y.

    2011-01-01

    Roč. 36, č. 2 (2011), s. 261-269 ISSN 0307-6946 Institutional research plan: CEZ:AV0Z40550506 Keywords : diet diversity * feeding groups * Isoptera * phylogenetic autocorrelation Subject RIV: CC - Organic Chemistry Impact factor: 1.995, year: 2011

  12. Impact of non-steroidal anti-inflammatory drugs (NSAIDs) on cardiovascular outcomes in patients with stable atherothrombosis or multiple risk factors.

    Science.gov (United States)

    Barthélémy, Olivier; Limbourg, Tobias; Collet, Jean Philippe; Beygui, Farzin; Silvain, Johanne; Bellemain-Appaix, Anne; Cayla, Guillaume; Chastre, Thomas; Baumgartner, Iris; Röther, Joachim; Zeymer, Uwe; Bhatt, Deepak L; Steg, Gabriel; Montalescot, Gilles

    2013-03-10

    We aimed to assess whether the use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with an increased risk of cardiovascular (CV) events in stable patients with established atherothrombosis or multiple risk factors. We analysed the 23,728 European patients of the REACH Registry; 20,588 (86.8%) had established atherothrombotic disease and 3140 (13.2%) had multiple risk factors only. Aspirin (ASA) and/or NSAIDs use was determined at enrolment and ischemic events were recorded over two years of follow-up. cMACCE was defined as the composite of CV death, MI or stroke. Bleeding was defined as any bleeding leading to both hospitalisation and transfusion. The mean age of population was 67.2±9.8years. At baseline, 1573 patients (6.6%) received NSAIDs and 15,395 (64.9%) received ASA. Four groups were defined: 1) no ASA/no NSAIDs, 2) ASA only, 3) NSAIDs only, 4) NSAIDs+ASA, with 7722 (32.5%), 14,433 (60.8%), 611 (2.6%) and 962 (4.1%) patients in these groups, respectively. Among the 22,028 (92.8%) with complete 2-year follow-up, 683 (3.2%) died from CV causes, while 395 (1.9%) had MI, 665 (3.1%) stroke, 1651 (7.6%) cMACCE and 199 (1.0%) bleeding. After adjustment, NSAID use was independently associated with an increased risk of stroke (OR 1.635; 95% CI 1.239-2.159, pNSAID use and MI or MACCE. In stable atherothrombosis patients, the use of NSAIDs appears to be independently associated with an increased cerebrovascular event risk. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  13. Structural and Kinetic Analyses of Macrophage Migration Inhibitory Factor Active Site Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Crichlow, G.; Lubetsky, J; Leng, L; Bucala, R; Lolis, E

    2009-01-01

    Macrophage migration inhibitory factor (MIF) is a secreted protein expressed in numerous cell types that counters the antiinflammatory effects of glucocorticoids and has been implicated in sepsis, cancer, and certain autoimmune diseases. Interestingly, the structure of MIF contains a catalytic site resembling the tautomerase/isomerase sites of microbial enzymes. While bona fide physiological substrates remain unknown, model substrates have been identified. Selected compounds that bind in the tautomerase active site also inhibit biological functions of MIF. It had previously been shown that the acetaminophen metabolite, N-acetyl-p-benzoquinone imine (NAPQI), covalently binds to the active site of MIF. In this study, kinetic data indicate that NAPQI inhibits MIF both covalently and noncovalently. The structure of MIF cocrystallized with NAPQI reveals that the NAPQI has undergone a chemical alteration forming an acetaminophen dimer (bi-APAP) and binds noncovalently to MIF at the mouth of the active site. We also find that the commonly used protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), forms a covalent complex with MIF and inhibits the tautomerase activity. Crystallographic analysis reveals the formation of a stable, novel covalent bond for PMSF between the catalytic nitrogen of the N-terminal proline and the sulfur of PMSF with complete, well-defined electron density in all three active sites of the MIF homotrimer. Conclusions are drawn from the structures of these two MIF-inhibitor complexes regarding the design of novel compounds that may provide more potent reversible and irreversible inhibition of MIF.

  14. Structure of a bacterial energy-coupling factor transporter.

    Science.gov (United States)

    Wang, Tingliang; Fu, Guobin; Pan, Xiaojing; Wu, Jianping; Gong, Xinqi; Wang, Jiawei; Shi, Yigong

    2013-05-09

    The energy-coupling factor (ECF) transporters constitute a novel family of conserved membrane transporters in prokaryotes that have a similar domain organization to the ATP-binding cassette transporters. Each ECF transporter comprises a pair of cytosolic ATPases (the A and A' components, or EcfA and EcfA'), a membrane-embedded substrate-binding protein (the S component, or EcfS) and a transmembrane energy-coupling component (the T component, or EcfT) that links the EcfA-EcfA' subcomplex to EcfS. The structure and transport mechanism of the quaternary ECF transporter remain largely unknown. Here we report the crystal structure of a nucleotide-free ECF transporter from Lactobacillus brevis at a resolution of 3.5 Å. The T component has a horseshoe-shaped open architecture, with five α-helices as transmembrane segments and two cytoplasmic α-helices as coupling modules connecting to the A and A' components. Strikingly, the S component, thought to be specific for hydroxymethyl pyrimidine, lies horizontally along the lipid membrane and is bound exclusively by the five transmembrane segments and the two cytoplasmic helices of the T component. These structural features suggest a plausible working model for the transport cycle of the ECF transporters.

  15. Synoptic Factors Affecting Structure Predictability of Hurricane Alex (2016)

    Science.gov (United States)

    Gonzalez-Aleman, J. J.; Evans, J. L.; Kowaleski, A. M.

    2016-12-01

    On January 7, 2016, a disturbance formed over the western North Atlantic basin. After undergoing tropical transition, the system became the first hurricane of 2016 - and the first North Atlantic hurricane to form in January since 1938. Already an extremely rare hurricane event, Alex then underwent extratropical transition [ET] just north of the Azores Islands. We examine the factors affecting Alex's structural evolution through a new technique called path-clustering. In this way, 51 ensembles from the European Centre for Medium-Range Weather Forecasts Ensemble Prediction System (ECMWF-EPS) are grouped based on similarities in the storm's path through the Cyclone Phase Space (CPS). The differing clusters group various possible scenarios of structural development represented in the ensemble forecasts. As a result, it is possible to shed light on the role of the synoptic scale in changing the structure of this hurricane in the midlatitudes through intercomparison of the most "realistic" forecast of the evolution of Alex and the other physically plausible modes of its development.

  16. Exploring Individual and Structural Factors Associated with Employment Among Young Transgender Women of Color Using a No-Cost Transgender Legal Resource Center.

    Science.gov (United States)

    Hill, Brandon J; Rosentel, Kris; Bak, Trevor; Silverman, Michael; Crosby, Richard; Salazar, Laura; Kipke, Michele

    2017-01-01

    The purpose of this study was to explore individual and structural factors associated with employment among young transgender women (TW) of color. Sixty-five trans women of color were recruited from the Transgender Legal Defense and Education Fund to complete a 30-min interviewer-assisted survey assessing sociodemographics, housing, workplace discrimination, job-seeking self-efficacy, self-esteem, perceived public passability, and transactional sex work. Logistic regression models revealed that stable housing (structural factor) and job-seeking self-efficacy (individual factor) were significantly associated with currently being employed. Our findings underscore the need for multilevel approaches to assist TW of color gain employment.

  17. What are the risk factors for dislocation in primary total hip arthroplasty? A multicenter case-control study of 128 unstable and 438 stable hips.

    Science.gov (United States)

    Fessy, M H; Putman, S; Viste, A; Isida, R; Ramdane, N; Ferreira, A; Leglise, A; Rubens-Duval, B; Bonin, N; Bonnomet, F; Combes, A; Boisgard, S; Mainard, D; Leclercq, S; Migaud, H

    2017-09-01

    Dislocation after total hip arthroplasty (THA) is a leading reason for surgical revision. The risk factors for dislocation are controversial, particularly those related to the patient and to the surgical procedure itself. The differences in opinion on the impact of these factors stem from the fact they are often evaluated using retrospective studies or in limited patient populations. This led us to carry out a prospective case-control study on a large population to determine: 1) the risk factors for dislocation after THA, 2) the features of these dislocations, and 3) the contribution of patient-related factors and surgery-related factors. Risk factors for dislocation related to the patient and procedure can be identified using a large case-control study. A multicenter, prospective case-control study was performed between January 1 and December 31, 2013. Four patients with stable THAs were matched to each patient with a dislocated THA. This led to 566 primary THA cases being included: 128 unstable, 438 stable. The primary matching factors were sex, age, initial diagnosis, surgical approach, implantation date and type of implants (bearing size, standard or dual-mobility cup). The patients with unstable THAs were 67±12 [37-73]years old on average; there were 61 women (48%) and 67 men (52%). Hip osteoarthritis (OA) was the main reason for the THA procedure in 71% (91/128) of the unstable group. The dislocation was posterior in 84 cases and anterior in 44 cases. The dislocation occurred within 3 months of the primary surgery in 48 cases (38%), 3 to 12 months after in 23 cases (18%), 1 to 5years after in 20 cases (16%), 5 to 10years after in 17 cases (13%) and more than 10years later in 20 cases. The dislocation recurred within 6 months of the initial dislocation in 23 of the 128 cases (18%). The risk factors for instability were a high ASA score with an odds ratio (OR) of 1.93 (95% CI: 1.4-2.6), neurological disability (cognitive, motor or psychiatric disorders) with

  18. Fundamental understanding of oxygen reduction and reaction behavior and developing high performance and stable hetero-structured cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xingbo [West Virginia Univ., Morgantown, WV (United States)

    2016-11-14

    New unique hetero-structured cathode has been developed in this project. La2NiO4+δ (LNO) as a surface catalyst with interstitial oxygen defects was introduced onto the state-of-the-art (La0.6Sr0.4)0.95Co0.2Fe0.8O3-δ (LSCF) cathode to enhance the surface-limited ORR kinetics on SOFC cathode. Furthermore, the hetero-structured cathode surface maintains high activity under electrode polarization with much less negative effects from surface cation segregation of Sr, which is known to cause degradation issues for conventional LSCF and LSC cathodes, thus improving the cathode long-term stability. The interface chemistry distribution and oxygen transport properties have been studied to prove the enhancement of power out and stability of LNO-infiltrated LSCF cathode. The further investigation demonstrates that CeO2 & La2-xNiO4+δ (x=0-0.2) co-infiltration is a simple and cost-effective method to improve both performance and stability of LSCF cathode by limiting nano-particles growth/delamination and further improve the surface stability. For the first time, a physical model is proposed to illustrate how unique interstitial species on hetero-structured cathode surface work to regulate the exchange rate of the incorporation reaction. Meanwhile, fundamental investigation of the surface oxygen exchange and bulk oxygen transport properties under over-potential conditions across cathode materials have been carried out in this project, which were discussed and compared to the Nernst equation that is generally applied to treat any oxide electrodes under equilibrium.

  19. Atomic structure of a stable high-index Ge surface: G2(103)-(4x1)

    DEFF Research Database (Denmark)

    Seehofer, L.; Bunk, O.; Falkenberg, G.

    1997-01-01

    Based on scanning tunneling microscopy and surface X-ray diffraction, we propose a complex structural model for the Ge(103)-(4 x 1) reconstruction. Each unit cell contains two (103) double steps, which gives rise to the formation of stripes of Ge atoms oriented in the [] direction....... The stripes and the spaces between them are covered with threefold-coordinated Ge adatoms. Charge is transferred from the bulk-like edge atoms of the double steps to the adatoms. The formation of the reconstruction can be explained in terms of stress relief, charge transfer, and minimization of the dangling...

  20. Stable structures and potential energy surface of the metallic clusters: Ni, Cu, Ag, Au, Pd, and Pt

    Science.gov (United States)

    Wu, Xia; Sun, Yan

    2017-06-01

    Metallic clusters have been widely studied due to their special electrical, optical, and catalytic properties. The many-body Gupta potential is applied to describe the interatomic interaction of Ni, Cu, Ag, Au, Pd, and Pt clusters, and their global minimal structures within 100 atoms are optimized using dynamic lattice searching (DLS) method. The configurational distribution of global minima is analyzed, and the geometrical difference among these clusters is demonstrated. Results show that the dominant motif of Ni and Cu clusters is the icosahedron, and in Ag and Au clusters the number of decahedra is slightly larger than that of the icosahedra. However, more face-centered cubic (fcc), stacking fault fcc, and amorphous structures are formed in Au clusters than in Ag clusters. Furthermore, the main motif of Pd and Pt clusters is the decahedron. In particular, Ni98 adopts a Leary tetrahedral motif, and Pt54 is a central vacant icosahedron. The difference related to the potential parameters of these metallic clusters is further investigated by energy analysis. Moreover, the potential energy surfaces (PES) of 38-atom metallic clusters is characterized in terms of conformational analysis. It was found that the sequence of the number of local minima on the PES from large to low is Ni, Cu, Ag, Pt, Pd, and Au.

  1. Structural and photoluminescence behavior of thermally stable Eu3+activated CaWO4 nanophosphors via Li+ incorporation

    Science.gov (United States)

    Ramakrishna, P. V.; Lakshmana Rao, T.; Singh, Arvind; Benarji, B.; Dash, S.

    2017-12-01

    We have studied the structural and photo physical analogue of Eu3+ activated CaWO4 nanophosphors via Lithium (Li+ = 2, 5 7 and 10 at.%) ion incorporation. As-prepared (APS) samples were annealed at 900 °C to eliminate unwanted organic moieties present in the sample and to improve crystallinity. The samples are characterized employing X-ray diffraction (XRD), Fourier transform IR spectroscopy (FTIR), UV-VIS spectroscopy, photoluminescence studies and lifetime decay studies. FTIR features an absorption band at ∼832 cm-1, which correspond to its antisymmetric vibrations into Osbnd Wsbnd O band in the WO42- tetrahedron. CaWO4 having the scheelite type structure with C4h point group and I41/a space group. The surface morphology of the samples are studied with Scanning Electron Microscopy (SEM). Lithium Co-doped CaWO4:Eu3+ nanoparticles show red luminescence because of strong host contribution and different energy transfer rates from host to Eu3+ ions under 266 nm excitations. Lithium ion enhances the crystallinity and radiative transition rate thus results in higher emissive property. Calculated CIE co-ordinates of these Li+ doped 900 °C annealed samples under 266 nm excitation is x = 0.65 & y = 0.34, which are closer to the standard of NTSC (x = 0.67 & y = 0.33). This material may be potential candidates for white light emitting diodes.

  2. PP3 forms stable tetrameric structures through hydrophobic interactions via the C-terminal amphipathic helix and undergoes reversible thermal dissociation and denaturation.

    Science.gov (United States)

    Pedersen, Lise R L; Nielsen, Søren B; Hansted, Jon G; Petersen, Torben E; Otzen, Daniel E; Sørensen, Esben S

    2012-01-01

    The milk protein proteose peptone component 3 (PP3), also called lactophorin, is a small phosphoglycoprotein that is expressed exclusively in lactating mammary tissue. The C-terminal part of the protein contains an amphipathic helix, which, upon proteolytic liberation, shows antibacterial activity. Previous studies indicate that PP3 forms multimeric structures and inhibits lipolysis in milk. PP3 is the principal component of the proteose peptone fraction of milk. This fraction is obtained by heating and acidifying skimmed milk, and in the dairy industry milk products are also typically exposed to treatments such as pasteurization, which potentially could result in irreversible denaturation and inactivation of bioactive components. We show here, by the use of CD, that PP3 undergoes reversible thermal denaturation and that the α-helical structure of PP3 remains stable even at gastric pH levels. This suggests that the secondary structure survives treatment during the purification and possibly some of the industrial processing of milk. Finally, asymmetric flow field-flow fractionation and multi-angle light scattering reveal that PP3 forms a rather stable tetrameric complex, which dissociates and unfolds in guanidinium chloride. The cooperative unfolding of PP3 was completely removed by the surfactant n-dodecyl-β-d-maltoside and by oleic acid. We interpret this to mean that the PP3 monomers associate through hydrophobic interactions via the hydrophobic surface of the amphipathic helix. These observations suggest that PP3 tetramers act as reservoirs of PP3 molecules, which in the monomeric state may stabilize the milk fat globule. © 2011 The Authors Journal compilation © 2011 FEBS.

  3. Recovery of Weak Factor Loadings When Adding the Mean Structure in Confirmatory Factor Analysis: A Simulation Study.

    Science.gov (United States)

    Ximénez, Carmen

    2015-01-01

    This article extends previous research on the recovery of weak factor loadings in confirmatory factor analysis (CFA) by exploring the effects of adding the mean structure. This issue has not been examined in previous research. This study is based on the framework of Yung and Bentler (1999) and aims to examine the conditions that affect the recovery of weak factor loadings when the model includes the mean structure, compared to analyzing the covariance structure alone. A simulation study was conducted in which several constraints were defined for one-, two-, and three-factor models. Results show that adding the mean structure improves the recovery of weak factor loadings and reduces the asymptotic variances for the factor loadings, particularly for the models with a smaller number of factors and a small sample size. Therefore, under certain circumstances, modeling the means should be seriously considered for covariance models containing weak factor loadings.

  4. Factor structure of Eating Disorders Inventory-2 in a Spanish sample.

    Science.gov (United States)

    Muro-Sans, P; Amador-Campos, J A; Peró-Cebollero, M

    2006-06-01

    To present basic statistics and analyze factor structure of EDI-2 in an adolescent non-clinical sample from Spain. An Exploratory Factor Analysis (EFA) was carried out with Principal Axis Factoring (PAF) and oblimin rotation, using raw scores. EFA presented a 21-factor structure with eigenvalues greater than 1. It was then forced into 11 and 5-factor solutions. The eleven-factor structure does not correspond with the 11 scales. A five-factor structure seems to be better suited than other factor solutions and presented higher reliability coefficients.

  5. Chronic irradiation as an ecological factor affecting genetic population structure

    International Nuclear Information System (INIS)

    Kal'chenko, V.A.; Kalabushkin, B.A.; Rubanovich, A.V.

    1991-01-01

    Genetic structure of two Centaurea scabiosa L. populations was studied by frequency distribution of leucine aminopeptidase (LAP) locus genotypes. The experimental population has been growing under conditions of chronic irradiation, with the dose per generation amounting to 1.2 to 25.5 Gy. In it, mutational variants are observed with a frequency of 5.4.10(-3)-4.5.10(-2) per generation (as compared to control population frequency at 5.4.10(-4)). Indexes for heterozygosity, mean number of genotypes, and effective number of alleles were higher in the experimental population. Segregation analysis revealed no differences in viability in the control population, and all genotypic combinations were found to be nearly neutral. In the experimental population, however, significant differences in relative viability of the genotypes were disclosed. The relative viability of heterozygotes for mutant allele C' was nearly maximum, while heterozygotes for other mutant alleles showed minimum viability. We reach the conclusion that the differences in genetic structure of the populations under investigation can be explained by the chronic irradiation factor that brought out differences in adaptability of both normal and mutant genotypes. The suggestion is that intra-locus interactions of the C' allele with normal alleles determine plant resistance to a wide range of unfavorable environmental conditions

  6. Ultra-stable Molecule-Surface Architectures at Metal Oxides: Structure, Bonding, and Electron-transfer Processes

    Energy Technology Data Exchange (ETDEWEB)

    Hamers, Robert John

    2013-12-07

    Research funded by this project focused on the development of improved strategies for functionalization of metal oxides to enhance charge-transfer processes relevant to solar energy conversion. Initial studies included Fe2O3, WO3, TiO2, SnO2, and ZnO as model oxide systems; these systems were chosen due to differences in metal oxidation state and chemical bonding types in these oxides. Later studies focused largely on SnO2 and ZnO, as these materials show particularly promising surface chemistry, have high electron mobility, and can be readily grown in both spherical nanoparticles and as elongated nanorods. New molecules were synthesized that allowed the direct chemical assembly of novel nanoparticle ?dyadic? structures in which two different oxide materials are chemically joined, leading to an interface that enhances the separation of of charge upon illumination. We demonstrated that such junctions enhance photocatalytic efficiency using model organic compounds. A separate effort focused on novel approaches to linking dye molecules to SnO2 and ZnO as a way to enhance solar conversion efficiency. A novel type of surface binding through

  7. Portuguese validation of the Short Health Anxiety Inventory: Factor structure, reliability, and factor invariance.

    Science.gov (United States)

    Morales, Alexandra; Reis, Sibília; Espada, José P; Orgilés, Mireia

    2016-09-01

    The Short Health Anxiety Inventory is a brief instrument to assess health anxiety widely used across countries; however, no validated version is available for Portuguese-speaking population. Factorial structure, reliability, and equivalency factor with the Spanish version were analyzed with Portuguese adolescents aged 14-18 years. A Portuguese adolescent cohort ( N = 629) and a comparative Spanish adolescent cohort ( N = 1502) were evaluated. The original two-factor version was the best fitting model for the Portuguese version. The reliability was excellent. Complete measurement invariance across both countries was supported. The Portuguese version of the Short Health Anxiety Inventory is a valid screening inventory to assess health anxiety in adolescents.

  8. The Factor Structure of the CA-MIR as Evaluated Using Confirmatory Factor Analysis

    OpenAIRE

    Paola Molina; Marta Casonato; Maria N. Sala; Silvia Testa

    2018-01-01

    Introduction: The aim of the current study was to evaluate the factor structure of the CArtes- Modèles Individuels de Relations (CA-MIR), a self-report questionnaire designed to tap into the relational strategies of adults that was developed by a French-speaking research group coordinated by Blaise Pierrehumbert. The CA-MIR's particular merit lies in the richness and complexity of the theoretical model underpinning it. However, to date, this model has only been partially reproduced in studies...

  9. The p Factor: One General Psychopathology Factor in the Structure of Psychiatric Disorders?

    Science.gov (United States)

    Caspi, Avshalom; Houts, Renate M; Belsky, Daniel W; Goldman-Mellor, Sidra J; Harrington, HonaLee; Israel, Salomon; Meier, Madeline H; Ramrakha, Sandhya; Shalev, Idan; Poulton, Richie; Moffitt, Terrie E

    2014-03-01

    Mental disorders traditionally have been viewed as distinct, episodic, and categorical conditions. This view has been challenged by evidence that many disorders are sequentially comorbid, recurrent/chronic, and exist on a continuum. Using the Dunedin Multidisciplinary Health and Development Study, we examined the structure of psychopathology, taking into account dimensionality, persistence, co-occurrence, and sequential comorbidity of mental disorders across 20 years, from adolescence to midlife. Psychiatric disorders were initially explained by three higher-order factors (Internalizing, Externalizing, and Thought Disorder) but explained even better with one General Psychopathology dimension. We have called this dimension the p factor because it conceptually parallels a familiar dimension in psychological science: the g factor of general intelligence. Higher p scores are associated with more life impairment, greater familiality, worse developmental histories, and more compromised early-life brain function. The p factor explains why it is challenging to find causes, consequences, biomarkers, and treatments with specificity to individual mental disorders. Transdiagnostic approaches may improve research.

  10. The p Factor: One General Psychopathology Factor in the Structure of Psychiatric Disorders?

    Science.gov (United States)

    Caspi, Avshalom; Houts, Renate M.; Belsky, Daniel W.; Goldman-Mellor, Sidra J.; Harrington, HonaLee; Israel, Salomon; Meier, Madeline H.; Ramrakha, Sandhya; Shalev, Idan; Poulton, Richie; Moffitt, Terrie E.

    2013-01-01

    Mental disorders traditionally have been viewed as distinct, episodic, and categorical conditions. This view has been challenged by evidence that many disorders are sequentially comorbid, recurrent/chronic, and exist on a continuum. Using the Dunedin Multidisciplinary Health and Development Study, we examined the structure of psychopathology, taking into account dimensionality, persistence, co-occurrence, and sequential comorbidity of mental disorders across 20 years, from adolescence to midlife. Psychiatric disorders were initially explained by three higher-order factors (Internalizing, Externalizing, and Thought Disorder) but explained even better with one General Psychopathology dimension. We have called this dimension the p factor because it conceptually parallels a familiar dimension in psychological science: the g factor of general intelligence. Higher p scores are associated with more life impairment, greater familiality, worse developmental histories, and more compromised early-life brain function. The p factor explains why it is challenging to find causes, consequences, biomarkers, and treatments with specificity to individual mental disorders. Transdiagnostic approaches may improve research. PMID:25360393

  11. Functional Aspects of the Solution Structure and Dynamics of PAF, a Highly Stable Antifungal Protein from Penicillium chrysogenum

    Science.gov (United States)

    Batta, Gyula; Barna, Teréz; Gáspári, Zoltán; Sándor, Szabolcs; Kövér, Katalin E.; Binder, Ulrike; Sarg, Bettina; Kaiserer, Lydia; Chhillar, Anil Kumar; Eigentler, Andrea; Leiter, Éva; Hegedüs, Nikoletta; Pócsi, István; Lindner, Herbert; Marx, Florentine

    2015-01-01

    Summary PAF is a promising antimycotic without toxic effects on mammalian cells and therefore may be a drug candidate against the often lethal Aspergillus infections in human. The pathogenesis of PAF on sensitive fungi involves G-protein coupled signaling followed by apoptosis. Here, the solution structure of this small, cationic, antifungal protein from Penicillium chrysogenum is determined by solution NMR. We proved that PAF belongs to the SCOP fold class of its closest homologue AFP from Aspergillus giganteus. PAF comprises five β—strands forming two orthogonally packed β—sheets sharing a common interface. The ambiguity in the assignment of two disulfide bonds of three was investigated by NMR dynamics combined with restrained molecular dynamics calculations. The clue could not be resolved: two ensembles with different disulfide patterns and the one with no S-S bond exhibit essentially the same fold. 15N relaxation dispersion and interference experiments did not reveal disulfide bond rearrangements via slow exchange. The measured order parameters and the 3.0 ns correlation time is appropriate for a compact monomeric protein of this size. We demonstrated by site-directed mutagenesis that the highly conserved and positively charged lysine-rich domain region on the surface enhances the toxicity of PAF. However, the efficacy of the OB fold is reduced in PAF compared to AFP, due to less solvent exposed aromatic regions explaining the absence of chitobiose binding. The present work lends further support to the understanding of the documented substantial differences between the mode of action of two highly homologous antifungal proteins. PMID:19459942

  12. Dietary Patterns Derived Using Exploratory and Confirmatory Factor Analysis are Stable and Generalizable Across Race, Region, and Gender Subgroups in the REGARDS Study

    Science.gov (United States)

    Judd, Suzanne E.; Letter, Abraham J.; Shikany, James M.; Roth, David L.; Newby, P. K.

    2015-01-01

    Background: Examining diet as a whole using dietary patterns as exposures is a complementary method to using single food or nutrients in studies of diet and disease, but the generalizability of intake patterns across race, region, and gender in the United States has not been established. Objective: To employ rigorous statistical analysis to empirically derive dietary patterns in a large bi-racial, geographically diverse population and examine whether results are stable across population subgroups. Design: The present analysis utilized data from 21,636 participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study who completed the Block 98 food frequency questionnaire. We employed exploratory factor analysis and confirmatory factor analyses on 56 different food groups iteratively and examined differences by race, region, and sex to determine the optimal factor solution in our sample. Results: Five dietary patterns emerged: the “Convenience” pattern was characterized by mixed dishes; the “Plant-based” pattern by fruits, vegetables, and fish; the “Sweets/Fats” pattern by sweet snacks, desserts, and fats and oils; the “Southern” pattern by fried foods, organ meat, and sweetened beverages; and the “Alcohol/Salads” pattern by beer, wine, liquor, and salads. Differences were most pronounced in the Southern pattern with black participants, those residing in the Southeast, and participants not completing high school having the highest scores. Conclusion: Five meaningful dietary patterns emerged in the REGARDS study and showed strong congruence across race, sex, and region. Future research will examine associations between these patterns and health outcomes to better understand racial disparities in disease and inform prevention efforts. PMID:25988129

  13. Recent advances in the management of chronic stable angina II. Anti-ischemic therapy, options for refractory angina, risk factor reduction, and revascularization

    Directory of Open Access Journals (Sweden)

    Richard Kones

    2010-08-01

    Full Text Available Richard KonesThe Cardiometabolic Research Institute, Houston, Texas, USAAbstract: The objectives in treating angina are relief of pain and prevention of disease ­progression through risk reduction. Mechanisms, indications, clinical forms, doses, and side effects of the traditional antianginal agents – nitrates, ß-blockers, and calcium channel ­blockers – are reviewed. A number of patients have contraindications or remain unrelieved from anginal discomfort with these drugs. Among newer alternatives, ranolazine, recently approved in the United States, indirectly prevents the intracellular calcium overload involved in cardiac ischemia and is a welcome addition to available treatments. None, however, are disease-modifying agents. Two options for refractory angina, enhanced external counterpulsation and spinal cord stimulation (SCS, are presented in detail. They are both well-studied and are effective means of treating at least some patients with this perplexing form of angina. Traditional modifiable risk factors for coronary artery disease (CAD – smoking, hypertension, dyslipidemia, ­diabetes, and obesity – account for most of the population-attributable risk. Individual therapy of high-risk patients differs from population-wide efforts to prevent risk factors from appearing or reducing their severity, in order to lower the national burden of disease. Current American College of Cardiology/American Heart Association guidelines to lower risk in patients with chronic angina are reviewed. The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE trial showed that in patients with stable angina, optimal medical therapy alone and percutaneous coronary intervention (PCI with medical therapy were equal in preventing myocardial infarction and death. The integration of COURAGE results into current practice is discussed. For patients who are unstable, with very high risk, with left main coronary artery lesions, in

  14. Structural factors associated with methamphetamine smoking among female sex workers in Tijuana, Mexico.

    Science.gov (United States)

    Conners, Erin E; Gaines, Tommi L; Strathdee, Steffanie A; Magis-Rodriguez, Carlos; Brouwer, Kimberly C

    2017-12-07

    Smoking methamphetamine is associated with increased risk of HIV among female sex workers (FSW). The structural context of substance use is an important shaper of individual behaviour; however, structural determinants of methamphetamine use among FSWs are largely unknown. We identified individual, structural and neighbourhood factors associated with smoking methamphetamine among FSWs in the border city of Tijuana, Baja California, Mexico. A prospective cohort of 301 FSWs sampled from indoor and outdoor sex work venues throughout Tijuana participated in quantitative surveys on behaviours and mapping of home and work neighbourhoods across three visits. Multinomial logistic regression using generalised estimating equations identified individual, structural and neighbourhood variables associated with smoking methamphetamine. Methamphetamine use, particularly smoking, was highly prevalent among FSWs. Over half (61%) of FSWs had ever used methamphetamine in their lifetime and at baseline, 38% currently smoked methamphetamine. Smoking methamphetamine daily was associated with living in the red light district [adjusted odds ratio (AOR) = 2.72, 95% confidence interval (CI) = 1.23-6.02] and with perceived homelessness, but only among women in a good financial situation (AOR = 4.08, 95% CI = 1.58-10.50). Smoking methamphetamine less than daily was associated with older age (AOR = 1.06, 95% CI = 1.02-1.10). Our findings point to the important dynamic between the residential environment and more severe methamphetamine use. FSWs may prioritise the purchase of methamphetamine over stable housing if they have the financial means. Given the high prevalence of smoking methamphetamine among FSWs in Tijuana, drug treatment options, especially for women living in the red light district, are needed. © 2017 Australasian Professional Society on Alcohol and other Drugs.

  15. The network structure of human personality according to the NEO-PI-R: matching network community structure to factor structure.

    Directory of Open Access Journals (Sweden)

    Rutger Goekoop

    Full Text Available INTRODUCTION: Human personality is described preferentially in terms of factors (dimensions found using factor analysis. An alternative and highly related method is network analysis, which may have several advantages over factor analytic methods. AIM: To directly compare the ability of network community detection (NCD and principal component factor analysis (PCA to examine modularity in multidimensional datasets such as the neuroticism-extraversion-openness personality inventory revised (NEO-PI-R. METHODS: 434 healthy subjects were tested on the NEO-PI-R. PCA was performed to extract factor structures (FS of the current dataset using both item scores and facet scores. Correlational network graphs were constructed from univariate correlation matrices of interactions between both items and facets. These networks were pruned in a link-by-link fashion while calculating the network community structure (NCS of each resulting network using the Wakita Tsurumi clustering algorithm. NCSs were matched against FS and networks of best matches were kept for further analysis. RESULTS: At facet level, NCS showed a best match (96.2% with a 'confirmatory' 5-FS. At item level, NCS showed a best match (80% with the standard 5-FS and involved a total of 6 network clusters. Lesser matches were found with 'confirmatory' 5-FS and 'exploratory' 6-FS of the current dataset. Network analysis did not identify facets as a separate level of organization in between items and clusters. A small-world network structure was found in both item- and facet level networks. CONCLUSION: We present the first optimized network graph of personality traits according to the NEO-PI-R: a 'Personality Web'. Such a web may represent the possible routes that subjects can take during personality development. NCD outperforms PCA by producing plausible modularity at item level in non-standard datasets, and can identify the key roles of individual items and clusters in the network.

  16. Examining the Impact of Gender on the Factor Structure of the Psychopathic Personality Inventory--Revised

    Science.gov (United States)

    Anestis, Joye C.; Caron, Kelly M.; Carbonell, Joyce L.

    2011-01-01

    Research on the factor structure of psychopathy has yielded mixed results, supporting anywhere from one to three factors. Additionally, most of this research has used all-male samples, and the possibility of structural invariance across gender has not been examined. Using a mixed-gender sample of 360 undergraduates, the factor structure of the…

  17. Crystal Structure of Human Plasma Platelet-Activating Factor Acetylhydrolase

    Energy Technology Data Exchange (ETDEWEB)

    Samanta, U.; Bahnson, B

    2008-01-01

    Human plasma platelet-activating factor (PAF) acetylhydrolase functions by reducing PAF levels as a general anti-inflammatory scavenger and is linked to anaphylactic shock, asthma, and allergic reactions. The enzyme has also been implicated in hydrolytic activities of other pro-inflammatory agents, such as sn-2 oxidatively fragmented phospholipids. This plasma enzyme is tightly bound to low and high density lipoprotein particles and is also referred to as lipoprotein-associated phospholipase A{sub 2}. The crystal structure of this enzyme has been solved from x-ray diffraction data collected to a resolution of 1.5{angstrom}. It has a classic lipase {alpha}/{beta}-hydrolase fold, and it contains a catalytic triad of Ser{sup 273}, His{sup 351}, and Asp{sup 296}. Two clusters of hydrophobic residues define the probable interface-binding region, and a prediction is given of how the enzyme is bound to lipoproteins. Additionally, an acidic patch of 10 carboxylate residues and a neighboring basic patch of three residues are suggested to play a role in high density lipoprotein/low density lipoprotein partitioning. A crystal structure is also presented of PAF acetylhydrolase reacted with the organophosphate compound paraoxon via its active site Ser{sup 273}. The resulting diethyl phosphoryl complex was used to model the tetrahedral intermediate of the substrate PAF to the active site. The model of interface binding begins to explain the known specificity of lipoprotein-bound substrates and how the active site can be both close to the hydrophobic-hydrophilic interface and at the same time be accessible to the aqueous phase.

  18. The Factor Structure of the CA-MIR as Evaluated Using Confirmatory Factor Analysis

    Directory of Open Access Journals (Sweden)

    Paola Molina

    2018-03-01

    Full Text Available Introduction: The aim of the current study was to evaluate the factor structure of the CArtes- Modèles Individuels de Relations (CA-MIR, a self-report questionnaire designed to tap into the relational strategies of adults that was developed by a French-speaking research group coordinated by Blaise Pierrehumbert. The CA-MIR's particular merit lies in the richness and complexity of the theoretical model underpinning it. However, to date, this model has only been partially reproduced in studies using exploratory analysis and has never been tested via confirmatory factor analysis (CFA.Objective and Method: We thus conducted CFA on data collected from a sample of 979 subjects, recruited using a snowball sampling method during the spring and fall of 2005. To assess if some item multidimensionality was present, we estimated both the independent clusters model (ICM-CFA and a model in which some zero loading restrictions were removed.Results: The results supported the originally proposed structure of the CA-MIR; the large majority of items were good indicators of the expected latent dimensions and only few items showed relevant secondary loadings or loaded in an unexpected factor. The instrument adequately differentiates the three attachment styles, taking into account both past and present experiences of attachment relationships, and providing a rich and complex assessment of multiple features of attachment. In terms of internal consistency, alpha values were satisfactory and comparable to those found in the original Swiss validation study.Conclusions: Our results are of key importance for both research and clinical work, given the lack of valid and easy-to-administer tools for evaluating adult attachment.

  19. The Factor Structure of the CA-MIR as Evaluated Using Confirmatory Factor Analysis.

    Science.gov (United States)

    Molina, Paola; Casonato, Marta; Sala, Maria N; Testa, Silvia

    2018-01-01

    Introduction: The aim of the current study was to evaluate the factor structure of the CArtes- Modèles Individuels de Relations (CA-MIR), a self-report questionnaire designed to tap into the relational strategies of adults that was developed by a French-speaking research group coordinated by Blaise Pierrehumbert. The CA-MIR's particular merit lies in the richness and complexity of the theoretical model underpinning it. However, to date, this model has only been partially reproduced in studies using exploratory analysis and has never been tested via confirmatory factor analysis (CFA). Objective and Method: We thus conducted CFA on data collected from a sample of 979 subjects, recruited using a snowball sampling method during the spring and fall of 2005. To assess if some item multidimensionality was present, we estimated both the independent clusters model (ICM-CFA) and a model in which some zero loading restrictions were removed. Results: The results supported the originally proposed structure of the CA-MIR; the large majority of items were good indicators of the expected latent dimensions and only few items showed relevant secondary loadings or loaded in an unexpected factor. The instrument adequately differentiates the three attachment styles, taking into account both past and present experiences of attachment relationships, and providing a rich and complex assessment of multiple features of attachment. In terms of internal consistency, alpha values were satisfactory and comparable to those found in the original Swiss validation study. Conclusions: Our results are of key importance for both research and clinical work, given the lack of valid and easy-to-administer tools for evaluating adult attachment.

  20. The factor structure of the self-directed learning readiness scale | de ...

    African Journals Online (AJOL)

    The factor structure of the Self-Directed Learning Readiness Scale (SDLRS) was investigated for Afrikaans and English-speaking first-year university students. Five factors were extracted and rotated to oblique simple structure for both groups. Four of the five factors were satisfactorily replicated. The fifth factor appeared to ...

  1. Lesion Mapping the Four-Factor Structure of Emotional Intelligence

    Science.gov (United States)

    Operskalski, Joachim T.; Paul, Erick J.; Colom, Roberto; Barbey, Aron K.; Grafman, Jordan

    2015-01-01

    Emotional intelligence (EI) refers to an individual’s ability to process and respond to emotions, including recognizing the expression of emotions in others, using emotions to enhance thought and decision making, and regulating emotions to drive effective behaviors. Despite their importance for goal-directed social behavior, little is known about the neural mechanisms underlying specific facets of EI. Here, we report findings from a study investigating the neural bases of these specific components for EI in a sample of 130 combat veterans with penetrating traumatic brain injury. We examined the neural mechanisms underlying experiential (perceiving and using emotional information) and strategic (understanding and managing emotions) facets of EI. Factor scores were submitted to voxel-based lesion symptom mapping to elucidate their neural substrates. The results indicate that two facets of EI (perceiving and managing emotions) engage common and distinctive neural systems, with shared dependence on the social knowledge network, and selective engagement of the orbitofrontal and parietal cortex for strategic aspects of emotional information processing. The observed pattern of findings suggests that sub-facets of experiential and strategic EI can be characterized as separable but related processes that depend upon a core network of brain structures within frontal, temporal and parietal cortex. PMID:26858627

  2. Application of nitrogen and carbon stable isotopes (δ(15N and δ(13C to quantify food chain length and trophic structure.

    Directory of Open Access Journals (Sweden)

    Matthew J Perkins

    Full Text Available Increasingly, stable isotope ratios of nitrogen (δ(15N and carbon (δ(13C are used to quantify trophic structure, though relatively few studies have tested accuracy of isotopic structural measures. For laboratory-raised and wild-collected plant-invertebrate food chains spanning four trophic levels we estimated nitrogen range (NR using δ(15N, and carbon range (CR using δ(13C, which are used to quantify food chain length and breadth of trophic resources respectively. Across a range of known food chain lengths we examined how NR and CR changed within and between food chains. Our isotopic estimates of structure are robust because they were calculated using resampling procedures that propagate variance in sample means through to quantified uncertainty in final estimates. To identify origins of uncertainty in estimates of NR and CR, we additionally examined variation in discrimination (which is change in δ(15N or δ(13C from source to consumer between trophic levels and among food chains. δ(15N discrimination showed significant enrichment, while variation in enrichment was species and system specific, ranged broadly (1.4‰ to 3.3‰, and importantly, propagated variation to subsequent estimates of NR. However, NR proved robust to such variation and distinguished food chain length well, though some overlap between longer food chains infers a need for awareness of such limitations. δ(13C discrimination was inconsistent; generally no change or small significant enrichment was observed. Consequently, estimates of CR changed little with increasing food chain length, showing the potential utility of δ(13C as a tracer of energy pathways. This study serves as a robust test of isotopic quantification of food chain structure, and given global estimates of aquatic food chains approximate four trophic levels while many food chains include invertebrates, our use of four trophic level plant-invertebrate food chains makes our findings relevant for a majority

  3. Application of Nitrogen and Carbon Stable Isotopes (δ15N and δ13C) to Quantify Food Chain Length and Trophic Structure

    Science.gov (United States)

    Perkins, Matthew J.; McDonald, Robbie A.; van Veen, F. J. Frank; Kelly, Simon D.; Rees, Gareth; Bearhop, Stuart

    2014-01-01

    Increasingly, stable isotope ratios of nitrogen (δ15N) and carbon (δ13C) are used to quantify trophic structure, though relatively few studies have tested accuracy of isotopic structural measures. For laboratory-raised and wild-collected plant-invertebrate food chains spanning four trophic levels we estimated nitrogen range (NR) using δ15N, and carbon range (CR) using δ13C, which are used to quantify food chain length and breadth of trophic resources respectively. Across a range of known food chain lengths we examined how NR and CR changed within and between food chains. Our isotopic estimates of structure are robust because they were calculated using resampling procedures that propagate variance in sample means through to quantified uncertainty in final estimates. To identify origins of uncertainty in estimates of NR and CR, we additionally examined variation in discrimination (which is change in δ15N or δ13C from source to consumer) between trophic levels and among food chains. δ15N discrimination showed significant enrichment, while variation in enrichment was species and system specific, ranged broadly (1.4‰ to 3.3‰), and importantly, propagated variation to subsequent estimates of NR. However, NR proved robust to such variation and distinguished food chain length well, though some overlap between longer food chains infers a need for awareness of such limitations. δ13C discrimination was inconsistent; generally no change or small significant enrichment was observed. Consequently, estimates of CR changed little with increasing food chain length, showing the potential utility of δ13C as a tracer of energy pathways. This study serves as a robust test of isotopic quantification of food chain structure, and given global estimates of aquatic food chains approximate four trophic levels while many food chains include invertebrates, our use of four trophic level plant-invertebrate food chains makes our findings relevant for a majority of ecological systems

  4. Application of nitrogen and carbon stable isotopes (δ(15)N and δ(13)C) to quantify food chain length and trophic structure.

    Science.gov (United States)

    Perkins, Matthew J; McDonald, Robbie A; van Veen, F J Frank; Kelly, Simon D; Rees, Gareth; Bearhop, Stuart

    2014-01-01

    Increasingly, stable isotope ratios of nitrogen (δ(15)N) and carbon (δ(13)C) are used to quantify trophic structure, though relatively few studies have tested accuracy of isotopic structural measures. For laboratory-raised and wild-collected plant-invertebrate food chains spanning four trophic levels we estimated nitrogen range (NR) using δ(15)N, and carbon range (CR) using δ(13)C, which are used to quantify food chain length and breadth of trophic resources respectively. Across a range of known food chain lengths we examined how NR and CR changed within and between food chains. Our isotopic estimates of structure are robust because they were calculated using resampling procedures that propagate variance in sample means through to quantified uncertainty in final estimates. To identify origins of uncertainty in estimates of NR and CR, we additionally examined variation in discrimination (which is change in δ(15)N or δ(13)C from source to consumer) between trophic levels and among food chains. δ(15)N discrimination showed significant enrichment, while variation in enrichment was species and system specific, ranged broadly (1.4‰ to 3.3‰), and importantly, propagated variation to subsequent estimates of NR. However, NR proved robust to such variation and distinguished food chain length well, though some overlap between longer food chains infers a need for awareness of such limitations. δ(13)C discrimination was inconsistent; generally no change or small significant enrichment was observed. Consequently, estimates of CR changed little with increasing food chain length, showing the potential utility of δ(13)C as a tracer of energy pathways. This study serves as a robust test of isotopic quantification of food chain structure, and given global estimates of aquatic food chains approximate four trophic levels while many food chains include invertebrates, our use of four trophic level plant-invertebrate food chains makes our findings relevant for a majority of

  5. Towards tricking a pathogen's protease into fighting infection: the 3D structure of a stable circularly permuted onconase variant cleavedby HIV-1 protease.

    Directory of Open Access Journals (Sweden)

    Mariona Callís

    Full Text Available Onconase® is a highly cytotoxic amphibian homolog of Ribonuclease A. Here, we describe the construction of circularly permuted Onconase® variants by connecting the N- and C-termini of this enzyme with amino acid residues that are recognized and cleaved by the human immunodeficiency virus protease. Uncleaved circularly permuted Onconase® variants are unusually stable, non-cytotoxic and can internalize in human T-lymphocyte Jurkat cells. The structure, stability and dynamics of an intact and a cleaved circularly permuted Onconase® variant were determined by Nuclear Magnetic Resonance spectroscopy and provide valuable insight into the changes in catalytic efficiency caused by the cleavage. The understanding of the structural environment and the dynamics of the activation process represents a first step toward the development of more effective drugs for the treatment of diseases related to pathogens expressing a specific protease. By taking advantage of the protease's activity to initiate a cytotoxic cascade, this approach is thought to be less susceptible to known resistance mechanisms.

  6. Factor Structure of the Chinese Version of the General Health Questionnaire (GHQ-30): A Confirmatory Factor Analysis.

    Science.gov (United States)

    Shek, Daniel T. L.

    1993-01-01

    Examined factor structure of responses to Chinese version of General Health Questionnaire from 2,150 Chinese secondary school students. Found that, although five-factor model (Anxiety, Depression, Inadequate Coping, Social Dysfunctioning, and Sleep Disturbances) was able to fit data, higher-order model with same five primary factors and…

  7. Factor structure of PTSD, and relation with gender in trauma survivors from India

    OpenAIRE

    Ruby Charak; Cherie Armour; Ask Elklit; Disket Angmo; Jon D. Elhai; Hans M. Koot

    2014-01-01

    Background: The factor structure of posttraumatic stress disorder (PTSD) has been extensively studied in Western countries. Some studies have assessed its factor structure in Asia (China, Sri Lanka, and Malaysia), but few have directly assessed the factor structure of PTSD in an Indian adult sample. Furthermore, in a largely patriarchal society in India with strong gender roles, it becomes imperative to assess the association between the factors of PTSD and gender. Objective: The purpose of t...

  8. Preliminary examination of food web structure of Nicola Lake (Taim Hydrological System, south Brazil using dual C and N stable isotope analyses

    Directory of Open Access Journals (Sweden)

    Alexandre M. Garcia

    Full Text Available Taim Ecological Reserve is located within the Taim Hydrological System and was created to protect a heterogeneous and productive landscape harboring exceptional biological diversity in southern Brazil. Using stable isotope ratio analyses of carbon (delta13C and nitrogen (delta15N, we provide a preliminary description of the food web structure, including estimates of production sources supporting fish populations and vertical trophic structure, within a representative lake of this system. A total of 21 organisms (5 macrophytes, 3 mollusks and 13 adult fishes representing 16 species were collected for isotope analysis. Fishes had delta13C values ranging from -24.30º/oo to -28.31º/oo , showing concordance with the range of values observed for macrophytes (-25.49 to -27.10º/oo, and suggesting that these plants could be a major carbon source supporting these fishes. delta13C signatures of Corbicula (-30.81º/oo and Pomacea (-24.26º/oo indirectly suggest that phytoplankton and benthic algae could be alternative carbon sources for some consumers. Nitrogen isotope ratios indicated approximately three consumer trophic levels. The pearl cichlid Geophagus brasiliensis was a primary consumer. Two catfishes (Trachelyopterus lucenai and Loricariichthys anus were secondary consumers. Two congeneric pike cichclids (Crenicichla lepidota and C. punctata, a catfish (Pimelodus maculatus and the characids Astyanax fasciatus and Oligosarcus robustus were tertiary consumers. Further studies including additional primary producers and consumers and greater sample numbers should be conducted to provide a more complete and detailed description of food web structure and dynamics within the reserve.

  9. Family structure and family education as the factors for personal development of preschooler

    Directory of Open Access Journals (Sweden)

    Golovey L.A.

    2016-06-01

    Full Text Available This article is devoted to analysis of personal characteristics of preschoolers in relation to the factors of gender, family structure (complete or one-parent, the presence of sibling and family upbringing (parenting styles, parent-child emotional interaction. The study involved 155 boys, 157 girls and 312 mothers from Saint-Petersburg, Novosibirsk and Arkhangelsk. The age of children — from 4 to 7 years. We used the test and projective techniques. The study revealed that children from single parent families had higher indicators of anxiety, insecurity, depressiveness, self-distrust, hostility, feeling of inferiority, conflicts and difficulties in communication. In families with pronounced overprotection and characteristics of an authoritarian style children had lower self- esteem and higher indicators of anxiety and hostility. Children's aggressiveness was more pronounced in the case of permissive style and instability of parenting style. It was shown that emotional well-being in the parent-child relationships can be regarded as a resource for personal development of the child: understanding the causes of child s state, empathy. However we revealed that one third part of mothers had difficulties in emotional interaction with children. The research was supported by the Russian Foundation for Humanities (project №13-06-00480 «The family as a resource of child´s mental development in stable and critical ontogenetic periods».

  10. Low paraoxonase 1 arylesterase activity and high von Willebrand factor levels are associated with severe coronary atherosclerosis in patients with non-diabetic stable coronary artery disease.

    Science.gov (United States)

    Ding, Jieying; Chen, Qizhi; Zhuang, Xing; Feng, Zhilei; Xu, Lili; Chen, Fuxiang

    2014-11-25

    Paraoxonase 1 (PON1) activity and von Willebrand factor (VWF) release are associated with lesion initiation in atherosclerosis. Diabetes can complicate coronary artery disease (CAD) due to the production of advanced glycation end products. This study evaluated PON1 activity and VWF levels in non-post-acute coronary syndrome, stable CAD (SCAD) patients without diabetes. Non-diabetic SCAD patients and patients experiencing acute stress periods were selected (n=130). Forty-seven cases with normal coronary angiography and 50 healthy individuals served as controls. The non-diabetic SCAD group was then stratified into single-vessel lesions, multiple-vessel lesions, and mild or severe luminal stenosis according to the number and the degree of luminal stenoses. Serum PON1 paraoxonase and arylesterase activities, and plasma VWF levels were measured, as well as serum total cholesterol, total triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and apolipoprotein A1. PON1 arylesterase activity was detected with an ordinary chemistry system using a novel phenylacetate derivative. Both PON1 paraoxonase and arylesterase were lower in the non-diabetic SCAD group, but VWF levels were higher (versus controls, all Pparaoxonase activity (OR=0.991), PON1 arylesterase activity (OR=0.981), and VWF (OR 2.854) influenced SCAD in multiple logistic regression. Decreased PON1 arylesterase activity and increased VWF levels were associated with severe atherosclerosis in non-diabetic SCAD patients. We also observed a slight negative correlation between VWF and PON1 paraoxonase/arylesterase. PON1 and VWF are detectable markers that may predict the severity of stenoses, ideally facilitating a non-diabetic SCAD diagnosis before the sudden onset of life-threatening symptoms.

  11. Method of Factor Extraction and Simple Structure of Data from Diverse Scientific Areas.

    Science.gov (United States)

    Thorndike, Robert M.

    To study the applicability of simple structure logic for factorial data from scientific disciplines outside psychology, four correlation matrices from each of six scientific areas were factor analyzed by five factoring methods. Resulting factor matrices were compared on two objective criteria of simple structure before and after rotation.…

  12. Examining the Factor Structure and Hierarchical Nature of the Quality of Life Construct

    Science.gov (United States)

    Wang, Mian; Schalock, Robert L.; Verdugo, Miguel A.; Jenaro, Christina

    2010-01-01

    There is considerable debate in the area of individual quality of life research regarding the factor structure and hierarchical nature of the quality of life construct. Our purpose in this study was to test via structural equation modeling an a priori quality of life model consisting of eight first-order factors and one second-order factor. Data…

  13. Efficient and stable, structurally inverted poly(3-hexylthiopen): [6,6]-phenyl-C61-butyric acid methyl ester heterojunction solar cells with fibrous like poly(3-hexylthiopen)

    International Nuclear Information System (INIS)

    Bandara, Jayasundera; Shankar, Karthik; Grimes, Craig A.; Thelakkat, Mukundan

    2011-01-01

    We investigated an inverted organic photovoltaic device structure in which a densely packed ∼ 100 nm thin TiO 2 layer on fluorine doped conducting glass serves as anode and poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)/Au layer on top of the active layer serves as cathode. The active layer is comprised of a blend of poly(3-hexylthiopene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The rectification behavior of such a device is improved significantly and injection losses are minimized compared to devices without any compact TiO 2 layer. Moreover, nanostructured P3HT active layer was achieved in-situ by spin coating concentrated pure P3HT and P3HT:PCBM blend and solar cell performances on thickness of the active layer were also investigated. For the inverted solar cells constructed with different concentrations of P3HT and PCBM keeping the P3HT:PCBM ratio 1:0.8 (wt.%), the highest short circuit current and efficiency was observed when the P3HT and PCBM concentration was equal to 1.5 (wt.%) and 1.2 (wt.%) respectively. This leads to highly stable and reproducible power conversion efficiency above 3.7% at 100 mW/cm 2 light intensity under AM 1.5 conditions.

  14. Synthesis and X-ray Crystal Structure of a Stable cis-1,2-bis(diphenylphosphinoethene Monodentate Thiolate Platinum Complex and TGA Studies of its Precursors

    Directory of Open Access Journals (Sweden)

    Vaz Rodrigo H.

    2002-01-01

    Full Text Available The stable Pt(II complex [Pt(SPh2(dppen (4, (dppen, Ph2PCH=CHPPh2 was obtained from [PtCl(SPh2(SnPh3cod] (1 (cod = 1,5-cyclooctadiene by reductive elimination reaction of SnClPh3 and substitution of the cod ligand by the diphosphine, albeit in low yields. Yields of 80% were obtained when [Pt(SPh2cod] (3 was used as the starting material instead. The viability of these reactions was suggested by a TG study, performed on the starting materials. Complex 4 was characterized by multinuclear NMR (195Pt, 31P, ¹H and 13C and IR spectroscopies and elemental analysis. The molecular structure, solved by an X-ray diffraction study, exhibted a slightly distorted square-planar geometry and short C=C and Pt-P bond distances which were interpreted in terms of a p interaction between the double bond and the metal-ligand bond, as observed for other diphosphine compounds described previously.

  15. Synergetic effects of solution-processable fluorinated graphene and PEDOT as a hole-transporting layer for highly efficient and stable normal-structure perovskite solar cells.

    Science.gov (United States)

    Yu, Jae-Hun; Lee, Cheol-Ho; Joh, Han-Ik; Yeo, Jun-Seok; Na, Seok-In

    2017-11-16

    We demonstrate that a bi-interlayer consisting of water-free poly(3,4-ethylenedioxythiophene) (PEDOT) and fluorinated reduced graphene oxide (FrGO) noticeably enhances the efficiency and the stability of the normal-structure perovskite solar cells (PeSCs). With simple and low temperature solution-processing, the PeSC employing the PEDOT + FrGO interlayer exhibits a significantly improved power conversion efficiency (PCE) of 14.9%. Comprehensive investigations indicate that the enhanced PCE is mostly attributed to the retarded recombination in the devices. The minimized recombination phenomena are related to the interfacial dipoles at the PEDOT/FrGO interface, which facilitates the electron-blocking and the higher built-in potential in the devices. Furthermore, the PEDOT + FrGO device shows a better stability by maintaining 70% of the initial PCE over the 30 days exposure to ambient conditions. This is because the more hydrophobic graphitic sheets of the FrGO on the PEDOT further protect the perovskite films from oxygen/water penetration. Consequently, the introduction of composite interfacial layers including graphene derivatives can be an effective and versatile strategy for high-performing, stable, and cost-effective PeSCs.

  16. Evidence of stable genetic structure across a remote island archipelago through self-recruitment in a widely dispersed coral reef fish

    KAUST Repository

    Priest, Mark

    2012-11-19

    We used microsatellite markers to assess the population genetic structure of the scribbled rabbitfish Siganus spinus in the western Pacific. This species is a culturally important food fish in the Mariana Archipelago and subject to high fishing pressure. Our primary hypothesis was to test whether the individuals resident in the southern Mariana Island chain were genetically distinct and hence should be managed as discrete stocks. In addition to spatial sampling of adults, newly-settled individuals were sampled on Guam over four recruitment events to assess the temporal stability of the observed spatial patterns, and evidence of self-recruitment. We found significant genetic structure in S. spinus across the western Pacific, with Bayesian analyses revealing three genetically distinct clusters: the southernMariana Islands, east Micronesia, and the west Pacific; with the southern Mariana Islands beingmore strongly differentiated fromthe rest of the region. Analyses of temporal samples from Guam indicated the southern Mariana cluster was stable over time, with no genetic differentiation between adults versus recruits, or between samples collected across four separate recruitment events spanning 11 months. Subsequent assignment tests indicated seven recruits had self-recruited from within the Southern Mariana Islands population. Our results confirm the relative isolation of the southern Mariana Islands population and highlight how local processes can act to isolate populations that, by virtue of their broad-scale distribution, have been subject to traditionally high gene flows. Our results add to a growing consensus that self-recruitment is a highly significant influence on the population dynamics of tropical reef fish. 2012 The Authors. Ecology and Evolution published by Blackwell Publishing Ltd.

  17. Factors related to the capital structure of small new ventures

    NARCIS (Netherlands)

    Harms, Rainer; Breitenecker, R.; Schwartz, E.J.; Wdowiak, M.A.

    2012-01-01

    In the literature, there exists evidence on the capital structure determinants for small ventures, but empirical research for new ventures is limited. We seek to address this gap by presenting a confirmatory analysis of determinants of capital structure of a sample of small new ventures in Austria.

  18. Factors mediating the restoration of structurally degraded soils

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Moldrup, Per; Schjønning, Per

    Soil structure is essential for sustained provision of ecosystem services such as water filtering and storage, waste disposal, carbon sequestration and many more. Structural degradation/disaggregation of soils emanating from human activities such as mining, grading and filling interferes...... with the ability of soils to perform these functions. The present study examines the roles of clay mineralogy, native organic matter, and exogenous organic material on the restoration of structurally degraded soils. Totally seven soils from Denmark and Ghana - five soils dominated by illites, one kaolinitic soil......, and one smectitic soil were sieved to 2 mm, and half of each soil amended with ground rape, packed in lysimeters, and incubated in the field for 20 months to monitor structure regeneration. During and after the incubation period, soil structure indicators and microbial activity were assessed. During...

  19. The Importance of Structure in Incomplete Factorization Preconditioners

    Czech Academy of Sciences Publication Activity Database

    Scott, J.; Tůma, Miroslav

    2011-01-01

    Roč. 51, č. 2 (2011), s. 385-404 ISSN 0006-3835 Grant - others:GA AV ČR(CZ) M100300902 Institutional research plan: CEZ:AV0Z10300504 Keywords : sparse symmetric linear systems * incomplete factorizations * preconditioners * level-based approach Subject RIV: BA - General Mathematics Impact factor: 0.724, year: 2011

  20. Establishing Evidence for Internal Structure Using Exploratory Factor Analysis

    Science.gov (United States)

    Watson, Joshua C.

    2017-01-01

    Exploratory factor analysis (EFA) is a data reduction technique used to condense data into smaller sets of summary variables by identifying underlying factors potentially accounting for patterns of collinearity among said variables. Using an illustrative example, the 5 general steps of EFA are described with best practices for decision making…

  1. The Crystal Structure of Cobra Venom Factor, a Cofactor for C3- and C5-Convertase CVFBb

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Vengadesan; Ponnuraj, Karthe; Xu, Yuanyuan; Macon, Kevin; Volanakis, John E.; Narayana, Sthanam V.L.; (Madras); (UAB)

    2009-05-26

    Cobra venom factor (CVF) is a functional analog of human complement component C3b, the active fragment of C3. Similar to C3b, in human and mammalian serum, CVF binds factor B, which is then cleaved by factor D, giving rise to the CVFBb complex that targets the same scissile bond in C3 as the authentic complement convertases C4bC2a and C3bBb. Unlike the latter, CVFBb is a stable complex and an efficient C5 convertase. We solved the crystal structure of CVF, isolated from Naja naja kouthia venom, at 2.6 {angstrom} resolution. The CVF crystal structure, an intermediate between C3b and C3c, lacks the TED domain and has the CUB domain in an identical position to that seen in C3b. The similarly positioned CUB and slightly displaced C345c domains of CVF could play a vital role in the formation of C3 convertases by providing important primary binding sites for factor B.

  2. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  3. Examining the impact of gender on the factor structure of the Psychopathic Personality Inventory-Revised.

    Science.gov (United States)

    Anestis, Joye C; Caron, Kelly M; Carbonell, Joyce L

    2011-09-01

    Research on the factor structure of psychopathy has yielded mixed results, supporting anywhere from one to three factors. Additionally, most of this research has used all-male samples, and the possibility of structural invariance across gender has not been examined. Using a mixed-gender sample of 360 undergraduates, the factor structure of the Psychopathic Personality Inventory-Revised was examined using confirmatory factor analysis and multiple group analysis. One-, two-, and three-factor models were tested and compared with each other. When males and females were combined, none of the three models provided adequate fit to the data. Multiple group analyses revealed partial invariance across gender for all three models. Model comparison criteria supported use of both the one- and two-factor models, taking into account variable factor structure across gender. The importance of considering structural differences based on biological sex when assessing psychopathic traits is discussed.

  4. Assessing the factor structure of a role functioning item bank.

    Science.gov (United States)

    Anatchkova, Milena D; Ware, John E; Bjorner, Jakob B

    2011-06-01

    Role functioning (RF) is an important part of health-related quality of life, but is hard to measure due to the wide definition of roles and fluctuations in role participation. This study aims to explore the dimensionality of a newly developed item bank assessing the impact of health on RF. A battery of measures with skip patterns including the new RF bank was completed by 2,500 participants answering only questions on social roles relevant to them. Confirmatory factor analyses were conducted for the participants answering items from all conceptual domains (N = 1193). Conceptually based dimensionality and method effects reflecting positively and negatively worded items were explored in a series of models. A bi-factor model (CFI = .93, RMSEA = .08) with one general and four conceptual factors (social, family, occupation, generic) was retained. Positively worded items were excluded from the final solution due to misfit. While a single factor model with methods factors had a poor fit (CFI = .88, RMSEA = .13), high loadings on the general factor in the bi-factor model suggest that the RF bank is sufficiently unidimensional for IRT analysis. The bank demonstrated sufficient unidimensionality for IRT-based calibration of all the items on a common metric and development of a computerized adaptive test.

  5. Oral health behavior among 25-year-old-Norwegian adults: factor structure, factorial invariance over time and trends.

    Science.gov (United States)

    Astrøm, Anne Nordrehaug

    2009-08-01

    Exploratory factor-analytical studies suggest that health behaviors are multidimensional, leading to hypotheses that such behaviors are bi- or tri-dimensional. This study applies confirmatory factor analysis (CFA), to semi-longitudinal data and provides new information about the factor structure of oral health-related behaviors among 25-year-old Norwegians. The purposes of the study were to (1) evaluate the factor structure of oral health behaviors and its invariance over time, (2) assess temporal changes in patterns of oral health behaviors and in their socioeconomic distribution between 1997 and 2007. Simple random samples of 1190 residents born in 1972 and 8000 residents born in 1982 were drawn from the populations of three counties in Western Norway in 1997 and 2007. Structured questionnaires were mailed to the eligible participants. After one reminder, 735 (58% women, response rate 62%) and 1509 (63.3% women, response rate 19%) replied. A correlated three-factor model with cross-loadings showed a better fit than a two-factor model to both the 1997 sample: chi(2)/df = 2.1, CFI = 0.95, RMSEA = 0.03 and the 2007 sample: chi2/df = 3.1, CFA = 0.95, RMSEA = 0.04. Multiple-group CFA showed an acceptable fit for the unconstrained model, CFA = 0.95, RMSEA = 0.03, and no statistically significant difference in fit between the unconstrained and constrained models (P = 0.739). Multiple binary logistic regression with three sum scores based on the behavioral factors sugar intake, drug use and oral health-enhancing behavior revealed that the odds ratios for frequent sugar intake (OR = 0.6, 95% CI: 0.5-0.8) and oral health-enhancing behavior (OR = 0.6, 95% CI: 0.5-0.7) were less in 2007 than in 1997. Drug use remained stable over time (OR = 0.9, 95% CI: 0.7-1.1). Educational differences in sugar intake observed in 1997 had leveled off in 2007. A three-factor structure fitted the data in 1997 and 2007 and the factor structure was invariant over time. This suggests that oral

  6. The Combination of Fosfomycin, Metronidazole, and Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor is Stable in vitro and Has Maintained Antibacterial Activity

    DEFF Research Database (Denmark)

    Fonnes, Siv; Holzknecht, Barbara Juliane; Gasbjerg, Lærke Smidt

    2017-01-01

    with the effect of the individual antibacterial agents. METHODS: The drugs were mixed to an aqueous solution. Basic chemical investigations of pH, precipitation, and calculated osmolarity of the drug combination were conducted. Fosfomycin and metronidazole's chemical stability was investigated using High Pressure......, was without precipitation, and had a calculated osmolarity of 293 mOsm/l. High Pressure Liquid Chromatography-Mass Spectrometry found stable concentrations of fosfomycin and metronidazole both alone and in combination during 24 h. The antibacterial effect of the drug combination solution was similar...... to the antibacterial effects of fosfomycin and metronidazole alone. CONCLUSION: The drug combination had neutral and stable pH, was iso-osmotic, and had stable concentrations during 24 h of storage. The antibacterial effect of fosfomycin and metronidazole were not altered when the drugs were mixed....

  7. Visualising the demographic factors which shape population age structure

    Directory of Open Access Journals (Sweden)

    Tom Wilson

    2016-09-01

    Full Text Available Background: The population pyramid is one of the most popular tools for visualising population age structure. However, it is difficult to discern from the diagram the relative effects of different demographic components on the size of age-specific populations, making it hard to understand exactly how a population's age structure is formed. Objective: The aim of this paper is to introduce a type of population pyramid which shows how births, deaths, and migration have shaped a population's age structure. Methods: Births, deaths, and population data were obtained from the Human Mortality Database and the Australian Bureau of Statistics. A variation on the conventional population pyramid, termed here a components-of-change pyramid, was created. Based on cohort population accounts, it illustrates how births, deaths, and net migration have created the population of each age group. A simple measure which summarises the impact of net migration on age structure is also suggested. Results: Example components-of-change pyramids for several countries and subnational regions are presented, which illustrate how births, deaths, and net migration have fashioned current population age structures. The influence of migration is shown to vary greatly between populations. Conclusions: The new type of pyramid aids interpretation of a population's age structure and helps to understand its demographic history over the last century.

  8. Biological activity in Technosols as a key factor of their structure

    Science.gov (United States)

    Watteau, Françoise; Villemin, Geneviève; Bouchard, Adeline; Monserié, Marie-France; Séré, Geoffroy; Schwartz, Christophe; Morel, Jean-Louis

    2010-05-01

    The studies of the dynamics of organic matters within soils, show that their structural stability depends on the biological activity bound to the degradation of organic products. We wondered what it was for Technosols there. We then tried to specify the contribution of this biological activity to the structure of three contrasted technosols : - Technosol 1: a material originated from a former steel industry containing steel and coke residues, which was deposited two years ago in lysimetric plots - Technosol 2: a constructed soil (30 months) resulting from the combination of paper-mill sludge, thermally treated soil material excavated from a former coking plant site, and green-waste compost - Technosol 3: 30 years old technosol developed on flotation ponds of a former steel mill with strong metallic pollution, on which grows a forest ecosystem If these 3 technosols presented initially a similar organic carbon content (around 70 g.kg-1), the origin of organic matters was different A follow-up of the structural stability of these 3 systems, based on techniques of granulometric soil fractionation and morphological/analytical characterization at ultrastructural scale (TEM/EDX), was realized. Results showed the specific contribution of organic matters to the formation of stable organo-mineral associations, in particular those belonging to (0-50 μm) fraction. They mainly involved organic matter from vegetal origin coming from the spontaneous colonization of these 3 sites, but also from microbial origin corresponding to rhizospheric bacteria producing exopolymers. Organic matters from the compost and cellulosic fibers from the paper-mill sludge also contributed to the formation of organo-mineral associations all the more that compost was also a source of microorganisms. Organic matters were also associated to pollutant metallic elements (Pb, Zn, Mn) initially brought by the materials, then highlighting their possible transfer and questioning about their (bio

  9. Assessing psychological distress in patients with skin diseases: reliability, validity and factor structure of the GHQ-12.

    Science.gov (United States)

    Picardi, A; Abeni, D; Pasquini, P

    2001-09-01

    We studied reliability, validity and factor structure of the 12-item General Health Questionnaire (GHQ-12) in dermatological patients. Subjects attending a dermatological outpatient clinic were administered the GHQ-12 and the Skindex-29. A random subsample was mailed another copy of the questionnaires to be completed within 1 week. A total of 2,579 subjects completed the GHQ-12. The internal consistency of the GHQ-12 was high (Cronbach's alpha = 0.88). Test-retest reliability on 137 subjects was also fairly satisfactory (intraclass correlation coefficient = 0.72), notwithstanding a re-test artefact probably related to reassurance from the physician. Evidence of construct validity was provided by the pattern of correlation between scores on the GHQ-12 and on the scales of Skindex-29, which were as hypothesized. Also, GHQ-12 scores of patients in different clinical groups varied as hypothesized, with patients affected by inflammatory skin diseases scoring significantly higher than patients with isolated skin lesions. We obtained both a two-factor and a three-factor solution: the latter seemed theoretically more appropriate, although the first may have practical advantages. A 'social dysfunction' factor emerged in both analyses, while the other items loaded on a 'general dysphoria' factor or on two separate factors interpreted as 'anxiety' and 'loss of self-esteem'. The GHQ-12 is a reliable and valid instrument with a factor structure that is quite stable across different samples as well as across diverse cultures. Its brevity and easiness of completion make it a useful tool to assess psychological distress in dermatological patients.

  10. Latent structure of the Wisconsin Card Sorting Test: a confirmatory factor analytic study.

    Science.gov (United States)

    Greve, Kevin W; Stickle, Timothy R; Love, Jeffrey M; Bianchini, Kevin J; Stanford, Matthew S

    2005-05-01

    The present study represents the first large scale confirmatory factor analysis of the Wisconsin Card Sorting Test (WCST). The results generally support the three factor solutions reported in the exploratory factor analysis literature. However, only the first factor, which reflects general executive functioning, is statistically sound. The secondary factors, while likely reflecting meaningful cognitive abilities, are less stable except when all subjects complete all 128 cards. It is likely that having two discontinuation rules for the WCST has contributed to the varied factor analytic solutions reported in the literature and early discontinuation may result in some loss of useful information. Continued multivariate research will be necessary to better clarify the processes underlying WCST performance and their relationships to one another.

  11. Structured plant metabolomics for the simultaneous exploration of multiple factors

    Science.gov (United States)

    Vasilev, Nikolay; Boccard, Julien; Lang, Gerhard; Grömping, Ulrike; Fischer, Rainer; Goepfert, Simon; Rudaz, Serge; Schillberg, Stefan

    2016-01-01

    Multiple factors act simultaneously on plants to establish complex interaction networks involving nutrients, elicitors and metabolites. Metabolomics offers a better understanding of complex biological systems, but evaluating the simultaneous impact of different parameters on metabolic pathways that have many components is a challenging task. We therefore developed a novel approach that combines experimental design, untargeted metabolic profiling based on multiple chromatography systems and ionization modes, and multiblock data analysis, facilitating the systematic analysis of metabolic changes in plants caused by different factors acting at the same time. Using this method, target geraniol compounds produced in transgenic tobacco cell cultures were grouped into clusters based on their response to different factors. We hypothesized that our novel approach may provide more robust data for process optimization in plant cell cultures producing any target secondary metabolite, based on the simultaneous exploration of multiple factors rather than varying one factor each time. The suitability of our approach was verified by confirming several previously reported examples of elicitor–metabolite crosstalk. However, unravelling all factor–metabolite networks remains challenging because it requires the identification of all biochemically significant metabolites in the metabolomics dataset. PMID:27853298

  12. Guide to Three Dimensional Structure and Motion Factorization

    CERN Document Server

    Wang, Guanghui

    2011-01-01

    The problem of structure and motion recovery from image sequences is an important theme in computer vision. Considerable progress has been made in this field during the past two decades, resulting in successful applications in robot navigation, augmented reality, industrial inspection, medical image analysis, and digital entertainment, among other areas. However, many of these methods work only for rigid objects and static scenes. The study of non-rigid structure from motion is not only of academic significance, but also has important practical applications in real-world, nonrigid or dynamic s

  13. Matrix factorization method for the Hamiltonian structure of ...

    Indian Academy of Sciences (India)

    S Ghosh, B Talukdar and S Chakraborti. The Hamiltonian structure of non-linear evolution equations solvable by the inverse spectral method was discovered in 1971 by Zakharov and Faddeev [2] and by Gardner [3] who interpreted the Kortweg-de Vries (KdV) equation as a completely integrable Hamilto- nian system in an ...

  14. A structural dynamic factor model for the effects of monetary policy estimated by the EM algorithm

    DEFF Research Database (Denmark)

    Bork, Lasse

    This paper applies the maximum likelihood based EM algorithm to a large-dimensional factor analysis of US monetary policy. Specifically, economy-wide effects of shocks to the US federal funds rate are estimated in a structural dynamic factor model in which 100+ US macroeconomic and financial time...... as opposed to the orthogonal factors resulting from the popular principal component approach to structural factor models. Correlated factors are economically more sensible and important for a richer monetary policy transmission mechanism. Secondly, I consider both static factor loadings as well as dynamic...

  15. Structural and functional characterization of human complement factor P

    DEFF Research Database (Denmark)

    Pedersen, Dennis

    The complement system is of great importance for the innate immune response, which can lead to opsonization and removal of invading pathogens, as well as immune complexes and damaged self-cells. Factor P (FP), also known as properdin, acts as a positive regulator of the alternative pathway...

  16. The Factor Structure of SCL-90 and MCMI Scale Scores.

    Science.gov (United States)

    Strauman, Timothy J.; Wetzler, Scott

    1992-01-01

    Scale-level factor analyses are reported for 2 self-report measures of psychopathology, the Symptom Checklist-90-R (SCL-90) and the Millon Clinical Multiaxial Inventory (MCMI), using 130 psychiatric inpatients and outpatients. Used separately, the measures offer limited interpretability of scale profiles. Their combined use permits differentiation…

  17. WRKY transcription factor superfamily: Structure, origin and functions

    African Journals Online (AJOL)

    WRKY transcription factors regulate the expression of pathogen-induced, senescence-induced, abscisic acid (ABA)-induced, gibberellic acid (GA)-induced and salcylic acid (SA)-induced genes and play an important role in the regulation of plant growth and development as well as in their response to many kinds of biotic ...

  18. How social structure changes in Chinese global cities: Synthesizing globalization, migration and institutional factors in Beijing

    NARCIS (Netherlands)

    Shi, Q.; Liu, T.; Musterd, S.; Cao, G.

    2017-01-01

    Recent studies on the social structural change in global cities have recognized globalization, migration, and institutional factors as three main forces underlying this process. However, effects of these factors have rarely been synthetically examined and the social structure of emerging Chinese

  19. Factor Structure and Psychometric Properties of the Injection Phobia Scale-Anxiety

    Science.gov (United States)

    Olatunji, Bunmi O.; Sawchuk, Craig N.; Moretz, Melanie W.; David, Bieke; Armstrong, Thomas; Ciesielski, Bethany G.

    2010-01-01

    The present investigation examined the factor structure and psychometric properties of the Injection Phobia Scale-Anxiety (IPS-Anx). Principal components analysis of IPS-Anx items in Study 1 (n = 498) revealed a 2-factor structure consisting of Distal Fear and Contact Fear. However, CFA results in Study 2 (n = 567) suggest that a 1-factor…

  20. Hamiltonian structure of isospectral deformation equation and semi-classical approximation to factorized S-matrices

    International Nuclear Information System (INIS)

    Chudnovsky, D.V.; Chudnovsky, G.V.

    1980-01-01

    We consider semi-classical approximation to factorized S-matrices. We show that this new class of matrices, called s-matrices, defines Hamiltonian structures for isospectral deformation equations. Concrete examples of factorized s-matrices are constructed and they are used to define Hamiltonian structure for general two-dimensional isospectral deformation systems. (orig.)

  1. Epidermal growth factor receptor structural alterations in gastric cancer

    International Nuclear Information System (INIS)

    Moutinho, Cátia; Mateus, Ana R; Milanezi, Fernanda; Carneiro, Fátima; Seruca, Raquel; Suriano, Gianpaolo

    2008-01-01

    EGFR overexpression has been described in many human tumours including gastric cancer. In NSCLC patients somatic EGFR mutations, within the kinase domain of the protein, as well as gene amplification were associated with a good clinical response to EGFR inhibitors. In gastric tumours data concerning structural alterations of EGFR remains controversial. Given its possible therapeutic relevance, we aimed to determine the frequency and type of structural alterations of the EGFR gene in a series of primary gastric carcinomas. Direct sequencing of the kinase domain of the EGFR gene was performed in a series of 77 primary gastric carcinomas. FISH analysis was performed in 30 cases. Association studies between EGFR alterations and the clinical pathological features of the tumours were performed. Within the 77 primary gastric carcinomas we found two EGFR somatic mutations and several EGFR polymorphisms in exon 20. Six different intronic sequence variants of EGFR were also found. Four gastric carcinomas showed balanced polysomy or EGFR gene amplification. We verified that gastric carcinoma with alterations of EGFR (somatic mutations or copy number variation) showed a significant increase of tumour size (p = 0.0094) in comparison to wild-type EGFR carcinomas. We demonstrate that EGFR structural alterations are rare in gastric carcinoma, but whenever present, it leads to tumour growth. We considered that searching for EGFR alterations in gastric cancer is likely to be clinically important in order to identify patients susceptible to respond to tyrosine kinase inhibitors

  2. Structure and RNA recognition of ribosome assembly factor Utp30.

    Science.gov (United States)

    Hu, Jianfei; Zhu, Xing; Ye, Keqiong

    2017-12-01

    The 90S preribosomes are gigantic early assembly intermediates of small ribosomal subunits. Cryo-EM structures of 90S were recently determined, but many of its components have not been accurately modeled. Here we determine the crystal structure of yeast Utp30, a ribosomal L1 domain-containing protein in 90S, at 2.65 Å resolution, revealing a classic two-domain fold. The structure of Utp30 fits well into the cryo-EM density of 90S, confirming its previously assigned location. Utp30 binds to the rearranged helix 41 of 18S rRNA and helix 4 of 5' external transcribed spacer in 90S. Comparison of RNA-binding modes of different L1 domains illustrates that they consistently recognize a short RNA duplex with the concaved surface of domain I, but are versatile in RNA recognition outside the core interface. Cic1 is a paralog of Utp30 associating with large subunit preribosomes. Utp30 and Cic1 share similar RNA-binding modes, suggesting that their distinct functions may be executed by a single protein in other organisms. Deletion of Utp30 does not affect the composition of 90S. The nonessential role of Utp30 could be ascribed to its peripheral localization and redundant interactions in 90S. © 2017 Hu et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  3. Robust Extraction of Circumstellar Structures with Nonnegative Matrix Factorization

    Science.gov (United States)

    Ren, Bin; Pueyo, Laurent; debes, John Henry; Ben Zhu, Guangtun; Duchene, Gaspard

    2018-01-01

    We apply the vectorized Non-negative Matrix Factorization (NMF) method to the post-processing of direct imaging data of exoplanetary systems such as circumstellar disks. NMF is an iterative approach that first creates a non-orthogonal and non-negative basis of components using the given reference images, then models a target with the components. The constructed model is then rescaled with a factor to compensate for the contribution from the disks. We compare NMF with existing methods (classical reference differential imaging method, and the Karhunen-Loeve image projection algorithm) using synthetic circumstellar disks, and demonstrate the superiority of NMF: with no need of prior selection of references, NMF can not only detect fainter circumstellar disks, but also better preserve their morphology. As an application to a real disk, we processed the archival Hubble Space Telescope STIS coronagraphic observations of HD 181327 with different methods and compared them.

  4. Structural factors in preschool children's emotional expression in music

    OpenAIRE

    Yrtti, Antti

    2011-01-01

    Recent studies have substantiated that preschool children are able to perceive the emotional meaning in music. However, to date, research has not paid enough attention to children’s emotional expression in music. The current study investigated 3- (N=18) and 5- (N=19) year-old children’s ability to express emotion with music by manipulating musical factors (pitch, loudness and tempo) to indicate one of three basic emotions (happiness, sadness or angriness). In order to facilitate the recogn...

  5. Factor Structure of Social Cognition in Schizophrenia: Is Empathy Preserved?

    OpenAIRE

    Corbera, Silvia; Wexler, Bruce E.; Ikezawa, Satoru; Bell, Morris D.

    2013-01-01

    Social cognitive impairments are core features of schizophrenia and are closely associated with poor functional outcome. This study sought to identify specific aspects of social cognition and their relationships to measures of social function, quality of life, and neurocognition. Principal component analysis was performed using social cognitive measures in patients with schizophrenia and healthy matched controls and revealed three factors: Interpersonal Discomfort, Basic Social Cognition, and...

  6. Determination of partial structure factors by reverse Monte Carlo modelling—a test of the method

    Science.gov (United States)

    Gruner, S.; Akinlade, O.; Hoyer, W.

    2006-05-01

    The reverse Monte Carlo modelling technique is commonly applied for the analysis of the atomic structure of liquid and amorphous substances. In particular, partial structure factors of multi-component alloys can be determined using this method. In the present study we use the example of the liquid Ni33Ge67 alloy to investigate the impact of different input data on the result of RMC modelling. It was found that even two experimental structure factors might be sufficient to obtain reliable partial structure factors if the contrast between them is high enough.

  7. Factor structure and psychometric properties of the General Health Questionnaire (GHQ-12) among Ghanaian adolescents.

    Science.gov (United States)

    Glozah, Franklin N; Pevalin, David J

    2015-01-01

    There is little information about the reliability and validity of the 12-item General Health Questionnaire (GHQ-12) in Ghana. This study sought to examine the reliability and factor structure of the GHQ-12 in Ghanaian adolescents. High school students (N = 770) completed the GHQ-12 and the Adolescent Stress Questionnaire (ASQ). Internal consistency, convergent validity and exploratory factor analysis were used. A two factor structure, each with six items, was extracted. The total GHQ-12 had acceptable internal consistency and a generally high correlation with the ASQ subscales. The GHQ-12 can be used in Ghanaian samples, but more research is needed to confirm its factor structure.

  8. Functional and structural stability of the epidermal growth factor receptor in detergent micelles and phospholipid nanodiscs

    DEFF Research Database (Denmark)

    Mi, Li-Zhi; Grey, Michael J; Nishida, Noritaka

    2008-01-01

    in detergent micelles and phospholipid bilayers. In the presence of EGF, catalytically active EGFR dimers can be isolated by gel filtration in dodecyl maltoside. Visualization of the dimeric species by negative stain electron microscopy and single particle averaging reveals an overall structure...... of the extracellular domain that is similar to previously published crystal structures and is consistent with the C-termini of domain IV being juxtaposed against one another as they enter the transmembrane domain. Although detergent-soluble preparations of EGFR are stable as dimers in the presence of EGF, they exhibit...

  9. Stable convergence and stable limit theorems

    CERN Document Server

    Häusler, Erich

    2015-01-01

    The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

  10. The Factor Structure and Validity of the Persian Version of the Baumrind Parenting Style Inventory

    OpenAIRE

    اصغر مینائی; سپیده نیک زاد

    2017-01-01

    In this study, the factor structure and validity of the Persian version of the Baumrind parenting style inventory were evaluated among 576 mothers of elementary school students in Tehran who had been selected through multistage cluster sampling method. This study is, due to its subject and purposes a descriptive study based on psychometric methods. The factor structure of the inventory was tested by AMOS software based on the fitting and modification indicators in the confirmatory factor anal...

  11. Structural and functional analysis of coral Hypoxia Inducible Factor.

    Science.gov (United States)

    Zoccola, Didier; Morain, Jonas; Pagès, Gilles; Caminiti-Segonds, Natacha; Giuliano, Sandy; Tambutté, Sylvie; Allemand, Denis

    2017-01-01

    Tissues of symbiotic Cnidarians are exposed to wide, rapid and daily variations of oxygen concentration. Indeed, during daytime, intracellular O2 concentration increases due to symbiont photosynthesis, while during night, respiration of both host cells and symbionts leads to intra-tissue hypoxia. The Hypoxia Inducible Factor 1 (HIF-1) is a heterodimeric transcription factor used for maintenance of oxygen homeostasis and adaptation to hypoxia. Here, we carried out a mechanistic study of the response to variations of O2 concentrations of the coral model Stylophora pistillata. In silico analysis showed that homologs of HIF-1 α (SpiHIF-1α) and HIF-1β (SpiHIF-1β) exist in coral. A specific SpiHIF-1 DNA binding on mammalian Hypoxia Response Element (HRE) sequences was shown in extracts from coral exposed to dark conditions. Then, we cloned the coral HIF-1α and β genes and determined their expression and transcriptional activity. Although HIF-1α has an incomplete Oxygen-dependent Degradation Domain (ODD) relative to its human homolog, its protein level is increased under hypoxia when tested in mammalian cells. Moreover, co-transfection of SpiHIF-1α and β in mammalian cells stimulated an artificial promoter containing HRE only in hypoxic conditions. This study shows the strong conservation of molecular mechanisms involved in adaptation to O2 concentration between Cnidarians and Mammals whose ancestors diverged about 1,200-1,500 million years ago.

  12. Non-negative Matrix Factorization: Robust Extraction of Extended Structures

    Science.gov (United States)

    Ren, Bin; Pueyo, Laurent; Ben Zhu, Guangtun; Debes, John; Duchêne, Gaspard

    2018-01-01

    We apply the vectorized non-negative matrix factorization (NMF) method to the post-processing of the direct imaging data of exoplanetary systems such as circumstellar disks. NMF is an iterative approach, which first creates a nonorthogonal and non-negative basis of components using the given reference images and then models a target with the components. The constructed model is then rescaled with a factor to compensate for the contribution from the disks. We compare NMF with existing methods (classical reference differential imaging method, and the Karhunen–Loève image projection algorithm) using synthetic circumstellar disks and demonstrate the superiority of NMF: with no need of prior selection of references, NMF not only can detect fainter circumstellar disks but also better preserves their morphology and does not require forward modeling. As an application to a well-known disk example, we process the archival Hubble Space Telescope STIS coronagraphic observations of HD 181327 with different methods and compare them, and NMF is able to extract some circumstellar materials inside the primary ring for the first time. In an appendix, we mathematically investigate the stability of NMF components during the iteration and the linearity of NMF modeling.

  13. Contingency factors that influence the design of organizational structure

    Directory of Open Access Journals (Sweden)

    Juan Alejandro Flores Castro

    2015-09-01

    Full Text Available Con la aplicación y el uso de los principios de la teoría de la empresa basada en los recursos y capacidades(RBV, se han identificado nuevos aspectos y factores de contingencia que inciden en el diseño de las estructurasorganizacionales de las empresas. Las características de un entorno global, dinámico y, cada vez, más competitivoen el que se desenvuelven las organizaciones hoy en día, exigen que las empresas encuentren nuevos modelosy esquemas para estructurar sus procesos, lograr una mayor flexibilidad en sus operaciones, otorgar un mayorgrado de empoderamiento a los colaboradores y reducir los niveles de jerarquía con el fin de facilitar lacomunicación y la toma de decisiones. Ante este escenario, los directivos de las empresas deben ser capacesde iniciar los procesos de reestructuración y proponer nuevos modelos de empresa, cada vez más horizontales,más virtuales y con colaboradores con mayor conocimiento, talento y capacidades para poder tomar decisiones.En este ensayo, los factores de contingencia estudiados están vinculados a la flexibilidad que se debe procuraren las organizaciones para alcanzar una posición de ventaja ante la competencia.

  14. Peplau's Theory of Interpersonal Relations: An Alternate Factor Structure for Patient Experience Data?

    Science.gov (United States)

    Hagerty, Thomas A; Samuels, William; Norcini-Pala, Andrea; Gigliotti, Eileen

    2017-04-01

    A confirmatory factor analysis of data from the responses of 12,436 patients to 16 items on the Consumer Assessment of Healthcare Providers and Systems-Hospital survey was used to test a latent factor structure based on Peplau's middle-range theory of interpersonal relations. A two-factor model based on Peplau's theory fit these data well, whereas a three-factor model also based on Peplau's theory fit them excellently and provided a suitable alternate factor structure for the data. Though neither the two- nor three-factor model fit as well as the original factor structure, these results support using Peplau's theory to demonstrate nursing's extensive contribution to the experiences of hospitalized patients.

  15. Factor Structure of the Korean Version of Wong and Law's Emotional Intelligence Scale

    Science.gov (United States)

    Fukuda, Eriko; Saklofske, Donald H.; Tamaoka, Katsuo; Lim, Hyunjung

    2012-01-01

    This study reports the factor structure of a Korean version of the 16-item Wong and Law Emotional Intelligence Scale (WLEIS) for a sample of 161 Korean university students. Confirmatory factor analysis supported the four-factor model of the WLEIS: (1) self-emotional appraisal, (2) others' emotional appraisal, (3) use of emotion, and (4) regulation…

  16. Herbivory of Omnivorous Fish Shapes the Food Web Structure of a Chinese Tropical Eutrophic Lake: Evidence from Stable Isotope and Fish Gut Content Analyses

    Directory of Open Access Journals (Sweden)

    Jian Gao

    2017-01-01

    Full Text Available Studies suggest that, unlike the situation in temperate lakes, high biomasses of omnivorous fish are maintained in subtropical and tropical lakes when they shift from a turbid phytoplankton-dominated state to a clear water macrophyte-dominated state, and the predation pressure on large-bodied zooplankton therefore remains high. Whether this reflects a higher degree of herbivory in warm lakes than in temperate lakes is debatable. We combined food web studies using stable isotopes with gut content analyses of the most dominant fish species to elucidate similarities and differences in food web structure between a clear water macrophyte-dominated basin (MDB and a turbid phytoplankton-dominated basin (PDB of Huizhou West Lake, a shallow tropical Chinese lake. The δ13C–δ15N biplot of fish and invertebrates revealed community-wide differences in isotope-based metrics of the food webs between MDB and PDB. The range of consumer δ15N (NR was lower in MDB than in PDB, indicating shorter food web length in MDB. The mean nearest neighbor distance (MNND and standard deviation around MNND (SDNND were higher in MDB than in PDB, showing a markedly low fish trophic overlap and a more uneven packing of species in niches in MDB than in PDB. The range of fish δ13C (CR of consumers was more extensive in MDB than in PDB, indicating a wider feeding range for fish in MDB. Mixing model results showed that macrophytes and associated periphyton constituted a large fraction of basal production sources for the fish in MDB, while particulate organic matter (POM contributed a large fraction in PDB. In MDB, the diet of the dominant fish species, crucian carp (Carassius carassius, consisted mainly of vegetal matter (macrophytes and periphyton and zooplankton, while detritus was the most important food item in PDB. Our results suggest that carbon from macrophytes with associated periphyton may constitute an important food resource for omnivorous fish, and this may strongly

  17. Determination of partial structure factors of disordered alloys

    International Nuclear Information System (INIS)

    Andonov, P.

    1993-01-01

    Often, isotopic substitution method in neutron diffraction or the differential anomalous X-ray scattering, cannot be applied; ancient results obtained from approximate methods are presented for three binary alloys: liquid Pd-Si (Si-Si contribution neglected in X-ray diffraction and assumed in neutron diffraction), liquid Cd-Zn (partial functions assumed independent of the concentration), amorphous Mg-Zn (correct CSRO determination but unsuccessful attempt of the three radiations method due to a structural evolution under the electron beam); accuracy and validity limits are recalled. The example of the ternary LiNbO 3 melt is considered: two diffraction experiments from X-rays and neutrons, in conjunction with the SAXS and the crystalline distribution, made it possible to describe a local order reduced to the first neighbours. 3 figs., 12 refs

  18. Structure and external factors of chinese city airline network

    Science.gov (United States)

    Liu, Hong-Kun; Zhang, Xiao-Li; Zhou, Tao

    2010-08-01

    Abstract We investigate the structural properties of Chinese city airline network (CCAN), where nodes and edges denote cities and direct flights. The degree distribution follows a double power law and a clear hierarchical layout is observed. The population exhibits a weakly positive correlation with the number of flights, yet it does not show obvious correlation with the transportation flow. The distance is an important parameter in CCAN, that is, the number of flights decays fast with the increasing of the distance. In comparison, the tertiary industry has the most important influence on the Chinese air passenger transportation. Statistically speaking, when the tertiary industry value increases by 1%, the next period's volume will increase by 0.73%.

  19. Structure-property relationship of bifunctional MnO2 nanostructures: highly efficient, ultra-stable electrochemical water oxidation and oxygen reduction reaction catalysts identified in alkaline media.

    Science.gov (United States)

    Meng, Yongtao; Song, Wenqiao; Huang, Hui; Ren, Zheng; Chen, Sheng-Yu; Suib, Steven L

    2014-08-13

    Manganese oxides of various structures (α-, β-, and δ-MnO2 and amorphous) were synthesized by facile methods. The electrocatalytic properties of these materials were systematically investigated for catalyzing both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in alkaline media. Extensive characterization was correlated with the activity study by investigating the crystal structures (XRD, HRTEM), morphologies (SEM), porosities (BET), surfaces (XPS, O2-TPD/MS), and electrochemical properties (Tafel analysis, Koutechy-Levich plots, and constant-current electrolysis). These combined results show that the electrocatalytic activities are strongly dependent on the crystallographic structures, and follow an order of α-MnO2 > AMO > β-MnO2 > δ-MnO2. Both OER studies and ORR studies reveal similar structure-determined activity trends in alkaline media. In the OER studies, α-MnO2 displays an overpotential of 490 mV compared to 380 mV shown by an Ir/C catalyst in reaching 10 mA cm(-2). Meanwhile, α-MnO2 also exhibits stability for 3 h when supplying a constant current density of 5 mA cm(-2). This was further improved by adding Ni(2+) dopants (ca. 8 h). The superior OER activity was attributed to several factors, including abundant di-μ-oxo bridges existing in α-MnO2 as the protonation sites, analogous to the OEC in PS-II of the natural water oxidation system; the mixed valencies (AOS = 3.7); and the lowest charge transfer resistances (91.8 Ω, η = 430 mV) as revealed from in situ electrochemical impedance spectroscopy (EIS). In the ORR studies, when reaching 3 mA cm(-2), α-MnO2 shows 760 mV close to 860 mV for the best ORR catalyst (20% Pt/C). The outstanding ORR activity was due to the strongest O2 adsorption capability of α-MnO2 suggested by temperature-programmed desorption. As a result, this discovery of the structure-related electrocatalytic activities could provide guidance in the further development of easily prepared, scalable, and low

  20. Factor Structure of Social Cognition in Schizophrenia: Is Empathy Preserved?

    Directory of Open Access Journals (Sweden)

    Silvia Corbera

    2013-01-01

    Full Text Available Social cognitive impairments are core features of schizophrenia and are closely associated with poor functional outcome. This study sought to identify specific aspects of social cognition and their relationships to measures of social function, quality of life, and neurocognition. Principal component analysis was performed using social cognitive measures in patients with schizophrenia and healthy matched controls and revealed three factors: Interpersonal Discomfort, Basic Social Cognition, and Empathy. Patients had higher scores on Interpersonal Discomfort and lower scores on Basic Social Cognition than controls, but the two groups were the same on Empathy. Lower social performance was significantly correlated with poor Basic Social Cognition in patients and with high Interpersonal Discomfort in controls. While neurocognition was significantly associated with Basic Social Cognition in both groups, it was not associated with Empathy. Social cognitive interventions should emphasize improving basic social cognitive processing deficits, managing Interpersonal Discomfort, and utilizing preserved capacity for empathy as a potential strength in social interactions.

  1. Factor Structure of the Eating Disorder Examination Interview in Patients With Binge-eating Disorder

    Science.gov (United States)

    Grilo, Carlos M.; Crosby, Ross D.; Peterson, Carol B.; Masheb, Robin M.; White, Marney A.; Crow, Scott J.; Wonderlich, Stephen A.; Mitchell, James E.

    2013-01-01

    Despite the widespread use of the Eating Disorder Examination (EDE) as a primary assessment instrument in studies of eating and weight disorders, little is known about the psychometric aspects of this interview measure. The primary purpose of this study was to evaluate the factor structure of the EDE interview in a large series of patients with binge-eating disorder (BED). Participants were 688 treatment-seeking patients with BED who were reliably administered the EDE interview by trained research clinicians at three research centers. Exploratory factor analysis (EFA) performed on EDE interview data from a random split-half of the study group suggested a brief 7-item 3-factor structure. Confirmatory factor analysis (CFA) performed on the second randomly selected half of the study group supported this brief 3-factor structure of the EDE interview. The three factors were interpreted as Dietary Restraint, Shape/Weight Overvaluation, and Body Dissatisfaction. In this series of patients with BED, factor analysis of the EDE interview did not replicate the original subscales but revealed an alternative factor structure. Future research must further evaluate the psychometric properties, including the factor structure, of the EDE interview in this and other eating-disordered groups. The implications of these factor analytic findings for understanding and assessing the specific psychopathology of patients with BED are discussed. PMID:19798064

  2. Bayes factor for testing between different structures of random genetic groups: a case study using weaning weight in Bruna dels Pirineus beef cattle.

    Science.gov (United States)

    Casellas, Joaquim; Piedrafita, Jesús; Varona, Luis

    2007-01-01

    The implementation of genetic groups in BLUP evaluations accounts for different expectations of breeding values in base animals. Notwithstanding, many feasible structures of genetic groups exist and there are no analytical tools described to compare them easily. In this sense, the recent development of a simple and stable procedure to calculate the Bayes factor between nested competing models allowed us to develop a new approach of that method focused on compared models with different structures of random genetic groups. The procedure is based on a reparameterization of the model in terms of intraclass correlation of genetic groups. The Bayes factor can be easily calculated from the output of a Markov chain Monte Carlo sampling by averaging conditional densities at the null intraclass correlation. It compares two nested models, a model with a given structure of genetic groups against a model without genetic groups. The calculation of the Bayes factor between different structures of genetic groups can be quickly and easily obtained from the Bayes factor between the nested models. We applied this approach to a weaning weight data set of the Bruna dels Pirineus beef cattle, comparing several structures of genetic groups, and the final results showed that the preferable structure was an only group for unknown dams and different groups for unknown sires for each year of calving.

  3. An investigation into the factor structure of the Ryff Scales of Psychological Well-Being

    Directory of Open Access Journals (Sweden)

    Carolina M. Henn

    2016-04-01

    Full Text Available Orientation: South African studies investigating the factor structure of the Ryff Scales of Psychological Well-being (RPWB are needed to ensure that the instrument is valid and reliable within the South African context.Research purpose: The objective of this study was to investigate the factor structure of the RPWB within two South African samples. Motivation for the study: Although a substantial number of studies have been undertaken, results regarding the factor structure of the Ryff Scales of Psychological Well-Being are inconclusive. There is a dearth of information in relation to South African studies examining the scales’ factor structure.Research design, approach and method: A quantitative research approach using a crosssectional field survey design was utilised. An adult working group (n = 202 was selected using convenience sampling, and a student group (n = 226 was selected by means of purposive non-probability sampling. An Exploratory Factor Analysis and a Confirmatory Factor Analysis were conducted to examine the factor structure.Main findings: The preferred model was a two-factor model where all the positively worded items were grouped in the first factor and all the negatively worded items were grouped in the second factor.Practical/managerial implications: The factor structure of the original RPWB was not satisfactorily replicated and remains seemingly unsettled. The utility of negatively worded items should be considered carefully, and alternatives such as mixed response options and phrase completion should be explored. The scales should be used with caution.Contribution/value-add: The study contributes to the literature concerning the factor structure of the RPWB with an emphasis on the South African context. It contributes to ensuring that researchers and practitioners use a valid and reliable instrument when measuring psychological well-being.

  4. Detection and analysis of unusual features in the structural model and structure-factor data of a birch pollen allergen.

    Science.gov (United States)

    Rupp, Bernhard

    2012-04-01

    Physically improbable features in the model of the birch pollen structure Bet v 1d (PDB entry 3k78) are faithfully reproduced in electron density generated with the deposited structure factors, but these structure factors themselves exhibit properties that are characteristic of data calculated from a simple model and are inconsistent with the data and error model obtained through experimental measurements. The refinement of the 3k78 model against these structure factors leads to an isomorphous structure different from the deposited model with an implausibly small R value (0.019). The abnormal refinement is compared with normal refinement of an isomorphous variant structure of Bet v 1l (PDB entry 1fm4). A variety of analytical tools, including the application of Diederichs plots, Rσ plots and bulk-solvent analysis are discussed as promising aids in validation. The examination of the Bet v 1d structure also cautions against the practice of indicating poorly defined protein chain residues through zero occupancies. The recommendation to preserve diffraction images is amplified. © 2012 International Union of Crystallography. All rights reserved.

  5. Pre- and Postintervention Factor Structure of Functional Independence Measure in Patients with Spinal Cord Injury

    Directory of Open Access Journals (Sweden)

    Mikhail Saltychev

    2017-01-01

    Full Text Available Objective. To evaluate the factor structure of Functional Independence Measure (FIM® scale amongst people with spinal cord injury (SCI. Methods. This was a retrospective, register-based cohort study on 155 rehabilitants with SCI. FIM was assessed at the beginning and at the end of multidisciplinary inpatient rehabilitation. The internal consistency of the FIM was assessed with Cronbach’s alpha and exploratory factor analysis was employed to approximate the construct structure of FIM. Results. The internal consistency demonstrated high Cronbach’s alpha of 0.95 to 0.96. For both pre- and postintervention assessments, the exploratory factor analysis resulted in 3-factor structures. Except for two items (“walking or using a wheelchair” and “expression”, the structures of the identified three factors remained the same from the beginning to the end of rehabilitation. The loadings of all items were sufficient, exceeding 0.3. Both pre- and postintervention chi-square tests showed significant p values < 0.0001. The “motor” domain was divided into two factors with this 2-factor structure enduring through the intervention period. Conclusions. Amongst rehabilitants with SCI, FIM failed to demonstrate unidimensionality. Instead, it showed a 3-factor structure that fluctuated only little depending on the timing of measurement. Additionally, when measured separately, also motor score was 2-dimensional, not 1-dimensional. Using a total or subscale FIM, scores seem to be unjustified in the studied population.

  6. The Eysenck Personality Questionnaire Brief Version: factor structure and reliability.

    Science.gov (United States)

    Sato, Toru

    2005-11-01

    The short scale of the Eysenck Personality Questionnaire-Revised (EPQR-S; H. J. Eysenck & S. B. G. Eysenck, 1992) is a 48-item personality questionnaire primarily designed to measure an individual's level of extraversion (vs. introversion) and neuroticism. Although L. J. Francis, L. B. Brown, and R. Philipchalk (1992) created the Eysenck Personality Questionnaire Revised-Abbreviated (EPQR-A), an even briefer version of the EPQR-S, the reliability coefficients of some of the measures have been less than satisfactory (S. Forrest, C. A. Lewis, & M. Shevlin, 2000). Because brevity and reliability are both extremely important, the author of the present study created a briefer version of the EPQR-S, more reliable than the EPQR-A, by making slight alterations in the item content as well as the response format of the EPQR-S. Two hundred and sixty eight participants completed the original EPQR-S and the 24-item newly revised briefer version of the EPQR-S (EPQ-BV) twice. The findings revealed that the EPQ-BV has good internal consistency, test-retest reliability, and concurrent validity. A principal component analysis revealed a solution with factor loadings that accurately reflected the primary measures of the EPQR-S. These findings are discussed in relation to the psychometric properties of the EPQR-A and the original version of the EPQR-S.

  7. Structural genomic variation as risk factor for idiopathic recurrent miscarriage

    DEFF Research Database (Denmark)

    Nagirnaja, Liina; Palta, Priit; Kasak, Laura

    2014-01-01

    Recurrent miscarriage (RM) is a multifactorial disorder with acknowledged genetic heritability that affects ∼3% of couples aiming at childbirth. As copy number variants (CNVs) have been shown to contribute to reproductive disease susceptibility, we aimed to describe genome-wide profile of CNVs an...... similar low duplication prevalence worldwide (0.7%-1.2%) compared to RM cases of this study (6.6%-7.5%). The CNV disrupts PDZD2 and GOLPH3 genes predominantly expressed in placenta and it may represent a novel risk factor for pregnancy complications....... and identify common rearrangements modulating risk to RM. Genome-wide screening of Estonian RM patients and fertile controls identified excessive cumulative burden of CNVs (5.4 and 6.1 Mb per genome) in two RM cases possibly increasing their individual disease risk. Functional profiling of all rearranged genes...... within RM study group revealed significant enrichment of loci related to innate immunity and immunoregulatory pathways essential for immune tolerance at fetomaternal interface. As a major finding, we report a multicopy duplication (61.6 kb) at 5p13.3 conferring increased maternal risk to RM in Estonia...

  8. Tuning the Structure and Ionic Interactions in a Thermochemically Stable Hybrid Layered Titanate-Based Nanocomposite for High Temperature Solid Lubrication

    NARCIS (Netherlands)

    Gonzalez Rodriguez, P.; Lubbers, Roy; Veldhuis, Sjoerd; Narygina, Olga; Lette, Walter; Schipper, Dirk J.; ten Elshof, Johan E.

    2017-01-01

    Solid inorganic lubricants are thermally stable but they are often limited by their lack of deformability, while organic lubricants have limitations in terms of thermal stability. In this study, a novel solid organic–inorganic nanocomposite lubricant that synergistically combines the

  9. Eutectic Gallium-Indium (EGaIn) : A Liquid Metal Alloy for the Formation of Stable Structures in Microchannels at Room Temperature

    NARCIS (Netherlands)

    Dickey, Michael D.; Chiechi, Ryan C.; Larsen, Ryan J.; Weiss, Emily A.; Weitz, David A.; Whitesides, George M.

    2008-01-01

    This paper describes the rheological behavior of the liquid metal eutectic gallium-indium (EGaIn) as it is injected into microfluidic channels to form stable microstructures of liquid metal. EGaIn is well-suited for this application because of its rheological properties at room temperature: it

  10. Examination of the factor structure of the Schizotypal Personality Questionnaire among British and Trinidadian adults.

    Science.gov (United States)

    Barron, David; Swami, Viren; Towell, Tony; Hutchinson, Gerard; Morgan, Kevin D

    2015-01-01

    Much debate in schizotypal research has centred on the factor structure of the Schizotypal Personality Questionnaire (SPQ), with research variously showing higher-order dimensionality consisting of two to seven dimensions. In addition, cross-cultural support for the stability of those factors remains limited. Here, we examined the factor structure of the SPQ among British and Trinidadian adults. Participants from a White British subsample (n = 351) resident in the UK and from an African Caribbean subsample (n = 284) resident in Trinidad completed the SPQ. The higher-order factor structure of the SPQ was analysed through confirmatory factor analysis, followed by multiple-group analysis for the model of best fit. Between-group differences for sex and ethnicity were investigated using multivariate analysis of variance in relation to the higher-order domains. The model of best-fit was the four-factor structure, which demonstrated measurement invariance across groups. Additionally, these data had an adequate fit for two alternative models: (a) 3-factor and (b) modified 4-factor model. The British subsample had significantly higher scores across all domains than the Trinidadian group, and men scored significantly higher on the disorganised domain than women. The four-factor structure received confirmatory support and, importantly, support for use with populations varying in ethnicity and culture.

  11. Non-negative matrix factorization and term structure of interest rates

    Science.gov (United States)

    Takada, Hellinton H.; Stern, Julio M.

    2015-01-01

    Non-Negative Matrix Factorization (NNMF) is a technique for dimensionality reduction with a wide variety of applications from text mining to identification of concentrations in chemistry. NNMF deals with non-negative data and results in non-negative factors and factor loadings. Consequently, it is a natural choice when studying the term structure of interest rates. In this paper, NNMF is applied to obtain factors from the term structure of interest rates and the procedure is compared with other very popular techniques: principal component analysis and Nelson-Siegel model. The NNMF approximation for the term structure of interest rates is better in terms of fitting. From a practitioner point of view, the NNMF factors and factor loadings obtained possess straightforward financial interpretations due to their non-negativeness.

  12. Factor structure of the Perceived Stress Scale (PSS) in a sample from Mexico.

    Science.gov (United States)

    Ramírez, Mónica Teresa González; Hernández, René Landero

    2007-05-01

    The aim of this study was to analyze the cultural adaptation of the European Spanish version of the Perceived Stress Scale (PSS; Cohen, Kamarak, & Mermelstein, 1983), for its use in Mexican samples. Using a random sample of students, internal consistency was analyzed and the factor structure of the Spanish version of the PSS was compared with the factor structure found in the English version. Internal consistency was adequate (alpha = .83) and confirmatory factor analysis corroborated the factor structure. Factor 1 explained 42.8% of the variance and Factor 2 accounted for 53.2%. The goodness-of-fit measures also revealed an adequate fit. The cultural adaptation of the PSS was also evaluated with satisfactory results.

  13. Internal consistency and factor structure of 12-item general health questionnaire in visually impaired students.

    Science.gov (United States)

    Bakhla, Ajay Kumar; Verma, Vijay; Hembram, Mahesh; Praharaj, Samir Kumar; Sinha, Vinod Kumar

    2013-07-01

    As there are no instruments to measure psychological wellness or distress in visually impaired students, we studied internal consistency and factor structure of GHQ-12 in visually impaired children. Internal consistency analysis (Cronbach's alpha and item total correlation) and exploratory factor analysis (principal component analysis) were carried out to identify factor structure of 12-item general health questionnaire (GHQ-12). All items of GHQ-12 were significantly associated with each other and the Cronbach's alpha coefficient for the scale was 0.7. On analysis of principal component, three-factor solution was found that accounted for 47.92% of the total variance. The factors included, 'general well-being', 'depression' and 'cognitive', with Cronbach's alpha coefficients being 0.70, 0.59, and 0.34, respectively. Our study findings suggest GHQ-12 is a reliable with adequate internal consistency scale and multidimensional factor structure in visually impaired students.

  14. The importance of building construction materials relative to other factors affecting structure survival during wildfire

    Science.gov (United States)

    Syphard, Alexandra D.; Brennan, Teresa J.; Keeley, Jon E.

    2017-01-01

    Structure loss to wildfire is a serious problem in wildland-urban interface areas across the world. Laboratory experiments suggest that fire-resistant building construction and design could be important for reducing structure destruction, but these need to be evaluated under real wildfire conditions, especially relative to other factors. Using empirical data from destroyed and surviving structures from large wildfires in southern California, we evaluated the relative importance of building construction and structure age compared to other local and landscape-scale variables associated with structure survival. The local-scale analysis showed that window preparation was especially important but, in general, creating defensible space adjacent to the home was as important as building construction. At the landscape scale, structure density and structure age were the two most important factors affecting structure survival, but there was a significant interaction between them. That is, young structure age was most important in higher-density areas where structure survival overall was more likely. On the other hand, newer-construction structures were less likely to survive wildfires at lower density. Here, appropriate defensible space near the structure and accessibility to major roads were important factors. In conclusion, community safety is a multivariate problem that will require a comprehensive solution involving land use planning, fire-safe construction, and property maintenance.

  15. stableGP

    Data.gov (United States)

    National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...

  16. Associations between alcohol use, other psychosocial factors, structural factors and antiretroviral therapy (ART) adherence among South African ART recipients.

    Science.gov (United States)

    Morojele, Neo K; Kekwaletswe, Connie T; Nkosi, Sebenzile

    2014-03-01

    We examined whether alcohol use is associated with antiretroviral therapy (ART) adherence independently of structural and psychosocial factors among 304 male and female ART recipients in ART sites in Tshwane, South Africa. ART adherence was assessed by the CASE Adherence Index. Independent variables were demographic, structural, psycho-social, and alcohol use (AUDIT score) factors. In hierarchical multiple regression, demographic variables (Step 1) explained 4 % of variance in ART adherence (p ≤ 0.01). Variance explained increased to 16 % (p ≤ 0.001) after entering structural variables (Step 2); 19 % (p ≤ 0.001) after entering psychosocial variables (Step 3); and 24 % (p ≤ 0.001) after entering AUDIT score (Step 4). Alcohol use is independently associated with ART adherence.

  17. Moving Aerospace Structural Design Practice to a Load and Resistance Factor Approach

    Science.gov (United States)

    Larsen, Curtis E.; Raju, Ivatury S.

    2016-01-01

    Aerospace structures are traditionally designed using the factor of safety (FOS) approach. The limit load on the structure is determined and the structure is then designed for FOS times the limit load - the ultimate load. Probabilistic approaches utilize distributions for loads and strengths. Failures are predicted to occur in the region of intersection of the two distributions. The load and resistance factor design (LRFD) approach judiciously combines these two approaches by intensive calibration studies on loads and strength to result in structures that are efficient and reliable. This paper discusses these three approaches.

  18. Factor Structure of a Multidimensional Gender Identity Scale in a Sample of Chinese Elementary School Children

    Directory of Open Access Journals (Sweden)

    Lu Yu

    2012-01-01

    Full Text Available This study examined the factor structure of a scale based on the four-dimensional gender identity model (Egan and Perry, 2001 in 726 Chinese elementary school students. Exploratory factor analyses suggested a three-factor model, two of which corresponded to “Felt Pressure” and “Intergroup Bias” in the original model. The third factor “Gender Compatibility” appeared to be a combination of “Gender Typicality” and “Gender Contentment” in the original model. Follow-up confirmatory factor analysis (CFA indicated that, relative to the initial four-factor structure, the three-factor model fits the current Chinese sample better. These results are discussed in light of cross-cultural similarities and differences in development of gender identity.

  19. Evaluating the Factor Structure of "Self-Concept" in Children: A Cautionary Note

    Science.gov (United States)

    Drummond, Robert J.; McIntire, Walter G.

    1977-01-01

    This article examines the factor structure of two measures of self-concept routinely used with elementary school children: the Coopersmith Self-Esteem Inventory and the Self-Concept and Motivation Inventory. (Author)

  20. Dynamic structure factor of the normal Fermi gas from the collisionless to the hydrodynamic regime

    International Nuclear Information System (INIS)

    Watabe, Shohei; Nikuni, Tetsuro

    2010-01-01

    The dynamic structure factor of a normal Fermi gas is investigated by using the moment method for the Boltzmann equation. We determine the spectral function at finite temperatures over the full range of crossover from the collisionless regime to the hydrodynamic regime. We find that the Brillouin peak in the dynamic structure factor exhibits a smooth crossover from zero to first sound as functions of temperature and interaction strength. The dynamic structure factor obtained using the moment method also exhibits a definite Rayleigh peak (ω∼0), which is a characteristic of the hydrodynamic regime. We compare the dynamic structure factor obtained by the moment method with that obtained from the hydrodynamic equations.

  1. Evaluating the Factor Structure of the Persian Version of Posttraumatic Growth Inventory in Cancer Patients

    Directory of Open Access Journals (Sweden)

    Mehdi Heidarzadeh, Ph.D., RN

    2017-09-01

    Conclusions: This study revealed that P-PTGI has an acceptable validity and reliability for posttraumatic growth assessment in Iranian cancer patients and its factor structure is similar to that of the original form developed by Tedeschi and Calhoun.

  2. The Factor Structure of the Schizotypal Personality Questionnaire in Undergraduate and Community Samples.

    Science.gov (United States)

    Zhang, Lisa C; Brenner, Colleen A

    2017-02-01

    The prevailing theoretical model of the Schizotypal Personality Questionnaire (SPQ) is a three-factor model based on subscale-level analyses. However, recent item-level factor analyses of the SPQ suggest a four- or five-factor model. To examine the factor structure of the SPQ and how this structure may differ between undergraduate and community samples, the authors conducted exploratory and confirmatory item-level factor analyses of this measure on undergraduate (N = 1,850) and community participants (N = 1,464). A clear three-factor solution was found in the community sample, whereas a somewhat equivocal four-factor solution was found in the undergraduate sample. Both structures displayed gender invariance. This is the first study to address the issues of undergraduate sample generalizability and gender invariance in an item-level exploratory factor analysis of the SPQ. Given the disparate findings in the samples, this study indicates the importance of using both community and undergraduate samples when examining the factor structure of the SPQ.

  3. An exploration of the factor structure of the nursing work index.

    Science.gov (United States)

    Slater, Paul; McCormack, Brendan

    2007-01-01

    The nurse shortage is increasing in the developed world. Organisational context is important in determining issues associated with nurse shortages, such as retention, recruitment, and job satisfaction. Recent research has utilised the Nursing Work Index-Revised (NWI-R) as a measure of organisational context traits. Within the NWI-R a four-factor model has been reported as being important in determining good organisational context, yet researchers have recently questioned the stability of the four-factor structure. No known study has attempted to replicate the four-factor structure reported in the NWI-R. The aim of this research is to examine the factor structure of the 15 items that comprise the four factors of the NWI-R. The NWI-R is an instrument that is focused on capturing organisational attributes that characterise professional nursing environments. A random sample of 172 (50%) acute care hospital nurses completed the NWI-R as part of a larger research project. The sample was diverse concerning nursing grade and specialty. Data were analysed using SPSS.11.0 to extract factors' structures (principal component and maximum likelihood), measures of homogeneity and descriptive statistics were generated from the findings. The four-factor structure of the NWI-R was not replicated in the data analysis. Instead a modified three-factor structure was identified accounting for 57% of the variance. Measures of internal consistency were acceptable. Previous research utilised the four factors of the NWI-R as a method to identify supportive organisational context and practice. The three-factor model raises questions regarding the stability of the findings using the NWI-R. This research shows the synthesis of the two models in light of previous findings. The findings might have far reaching implications for research that has utilised the NWI-R as a measure of organisational context. Further research is required to examine this study's findings and literature.

  4. Structure discrimination for the C-terminal domain of Escherichia coli trigger factor in solution

    International Nuclear Information System (INIS)

    Yao Yong; Bhabha, Gira; Kroon, Gerard; Landes, Mindy; Dyson, H. Jane

    2008-01-01

    NMR measurements can give important information on solution structure, without the necessity for a full-scale solution structure determination. The C-terminal protein binding domain of the ribosome-associated chaperone protein trigger factor is composed of non-contiguous parts of the polypeptide chain, with an interpolated prolyl isomerase domain. A construct of the C-terminal domain of Escherichia coli trigger factor containing residues 113-149 and 247-432, joined by a Gly-Ser-Gly-Ser linker, is well folded and gives excellent NMR spectra in solution. We have used NMR measurements on this construct, and on a longer construct that includes the prolyl isomerase domain, to distinguish between two possible structures for the C-terminal domain of trigger factor, and to assess the behavior of the trigger factor C-terminal domain in solution. Two X-ray crystal structures, of intact trigger factor from E. coli (Ferbitz et al., Nature 431:590-596, 2004), and of a truncated trigger factor from Vibrio cholerae (Ludlam et al., Proc Natl Acad Sci USA 101:13436-13441, 2004) showed significant differences in the structure of the C-terminal domain, such that the two structures could not be superimposed. We show using NMR chemical shifts and long range nuclear Overhauser effects that the secondary and tertiary structure of the E. coli C-terminal domain in solution is consistent with the crystal structure of the E. coli trigger factor and not with the V. cholerae protein. Given the similarity of the amino acid sequences of the E. coli and V. cholerae proteins, it appears likely that the structure of the V. cholerae protein has been distorted as a result of truncation of a 44-amino acid segment at the C-terminus. Analysis of residual dipolar coupling measurements shows that the overall topology of the solution structure is completely inconsistent with both structures. Dynamics analysis of the C-terminal domain using T 1 , T 2 and heteronuclear NOE parameters show that the protein is

  5. The vaccinia virus DNA polymerase structure provides insights into the mode of processivity factor binding

    Czech Academy of Sciences Publication Activity Database

    Tarbouriech, N.; Ducournau, C.; Hutin, S.; Mas, P.J.; Man, Petr; Forest, E.; Hart, D.J.; Peyrefitte, Ch.N.; Burmeister, W.P.; Iseni, F.

    2017-01-01

    Roč. 8, NOV 13 (2017), s. 1-12, č. článku 1455. ISSN 2041-1723 R&D Projects: GA MŠk(CZ) LQ1604 Institutional support: RVO:61388971 Keywords : PROTEIN SECONDARY STRUCTURE * CRYSTAL- STRUCTURE * GENETIC-CHARACTERIZATION Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 12.124, year: 2016

  6. Factor Structure of the New Imaginary Audience Scale in a Sample of Female College Students

    Science.gov (United States)

    Kuterbach, James M.

    2007-01-01

    The New Imaginary Audience Scale (NIAS; Lapsley, FitzGerald, Rice, & Jackson, 1989) has been used as a research tool with both high school and college aged samples, yet there is no structural validity evidence for its use with college students. This study examined the structural validity of the NIAS via an exploratory factor analysis, using a…

  7. Evaluating response modification factor (R for some types of steel structure

    Directory of Open Access Journals (Sweden)

    Doralba Valencia Restrepo

    2008-01-01

    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.

  8. Structure of rat acidic fibroblast growth factor at 1.4 A resolution

    DEFF Research Database (Denmark)

    Kulahin, Nikolaj; Kiselyov, Vladislav; Kochoyan, Artur

    2007-01-01

    Fibroblast growth factors (FGFs) constitute a family of 22 structurally related heparin-binding polypeptides that are involved in the regulation of cell growth, survival, differentiation and migration. Here, a 1.4 A resolution X-ray structure of rat FGF1 is presented. Two molecules are present...

  9. Reliability-Based Calibration of Load Duration Factors for Timber Structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Svensson, Staffan; Stang, Birgitte Friis Dela

    2005-01-01

    John Dalsgaard Sørensen, Staffan Svensson, Birgitte Dela Stang : Reliability-Based Calibration of Load Duration Factors for Timber Structures     Abstract :   The load bearing capacity of timber structures decrease with time depending on the type of load and timber. Based on representative limit ...

  10. Factor Structure of the Strengths and Difficulties Questionnaire in a Canadian Elementary School Sample

    Science.gov (United States)

    Aitken, Madison; Martinussen, Rhonda; Wolfe, Richard G.; Tannock, Rosemary

    2015-01-01

    The Strengths and Difficulties Questionnaire (SDQ) is a 25-item screening measure for emotional and behavioral problems in children and adolescents aged 4 to 16. Structural equation modeling was used to test the five-factor structure of teacher and parent ratings on the British version of the SDQ in a community sample of 501 Canadian children aged…

  11. Reliability and Concurrent Validation of the IPIP Big-Five Factor Markers in China: Consistencies in Factor Structure between Internet-Obtained Heterosexual and Homosexual Samples

    OpenAIRE

    Zheng, Lijun; Goldberg, Lewis R.; Zheng, Yong; Zhao, Yufang; Tang, Yonglong; Liu, Li

    2008-01-01

    Previous studies have suggested the cross-cultural generalizability of a 5-factor structure for personality traits. In this article, we analyzed the utility of 2 versions (100-item and 50-item) of the IPIP Big-Five factor markers in both heterosexual (N = 633) and homosexual (N = 437) samples in China. Factor analysis within versions showed that both versions of these IPIP measures showed clear 5-factor orthogonal structures that were nearly identical to the American structure in both subject...

  12. The Factor Structure of The Working Alliance Inventory in Cognitive-Behavioral Therapy

    Science.gov (United States)

    Andrusyna, Tomasz P.; Tang, Tony Z.; DeRubeis, Robert J.; Luborsky, Lester

    2001-01-01

    Studies of the therapeutic alliance in cognitive-behavioral therapy (CBT) have varied in their results, necessitating a deeper understanding of this construct. Through an exploratory factor analysis of the alliance in CBT, as measured by the Working Alliance Inventory (shortened, observer-rated version), the authors found a two-factor structure of alliance that challenges the commonly accepted one general factor of alliance. The results suggest that the relationship between therapist and client (Relationship) may be largely independent of the client's agreement with and confidence in the therapist and CBT (Agreement/ Confidence), necessitating independent measures of these two factors, not one measure of a general alliance factor. PMID:11402080

  13. Identifying the Best-Fitting Factor Structure of the Experience of Close Relations

    DEFF Research Database (Denmark)

    Esbjørn, Barbara Hoff; Breinholst, Sonja; Niclasen, Janni

    2015-01-01

    The aim of this study was to enhance the understanding of cultural and sample differences in the assessment of attachment by examining the factor structure of the Experiences in Close Relationships-Revised (ECR-R). The ECR-R is a self-report measure of adult roman- tic attachment dimensions...... study using the original ECR suggested that Scandinavian samples may best be described using a five-factor solution. Our results indicated that the one- and two-factor models of the ECR-R did not fit the data well. Exploratory Factor Analysis revealed a five- factor model. Our study provides evidence...

  14. Factor Structure and Psychometric Properties of the Young Schema Questionnaire (Short Form) in Chinese Undergraduate Students

    Science.gov (United States)

    Cui, Lixia; Lin, Wenwen; Oei, Tian P. S.

    2011-01-01

    This study investigated cross-cultural differences in the factor structure and psychometric properties of the Young Schema Questionnaire (short form; YSQ-SF). The participants were 712 Chinese undergraduate students. The total sample was randomly divided into two sub-samples. Exploratory Factor Analysis (EFA) was conducted on questionnaire results…

  15. Orthogonal Higher Order Structure of the WISC-IV Spanish Using Hierarchical Exploratory Factor Analytic Procedures

    Science.gov (United States)

    McGill, Ryan J.; Canivez, Gary L.

    2016-01-01

    As recommended by Carroll, the present study examined the factor structure of the Wechsler Intelligence Scale for Children-Fourth Edition Spanish (WISC-IV Spanish) normative sample using higher order exploratory factor analytic techniques not included in the WISC-IV Spanish Technical Manual. Results indicated that the WISC-IV Spanish subtests were…

  16. Homework Management Scale: Confirming the Factor Structure with Middle School Students in China

    Science.gov (United States)

    Xu, Jianzhong; Fan, Xitao; Du, Jianxia

    2015-01-01

    This study presents a psychometric evaluation of the Homework Management Scale (HMS) for mathematics, consisting of five subscales for measuring homework management strategies. Confirmatory factor analyses were conducted with a sample of middle school students (N = 796). Results indicated that the factor structure of the Chinese version of the HMS…

  17. Novel Perturbation Approach for the Structure Factor of the Attractive Hard-Core Yukawa Fluid.

    Czech Academy of Sciences Publication Activity Database

    Melnyk, R.; Moučka, F.; Nezbeda, Ivo; Trokhymchuk, A.

    2007-01-01

    Roč. 127, 9 (2007) , s. 094510-094517 ISSN 0021-9606 R&D Projects: GA AV ČR(CZ) IAA400720710 Institutional research plan: CEZ:AV0Z40720504 Keywords : equilibrium statistic al mechanics * statistic structure factor * phase-diagrams Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.044, year: 2007

  18. Factor Structure Analysis of the Schutte Self-Report Emotional Intelligence Scale on International Students

    Science.gov (United States)

    Ng, Kok-Mun; Wang, Chuang; Kim, Do-Hong; Bodenhorn, Nancy

    2010-01-01

    The authors investigated the factor structure of the Schutte Self-Report Emotional Intelligence (SSREI) scale on international students. Via confirmatory factor analysis, the authors tested the fit of the models reported by Schutte et al. and five other studies to data from 640 international students in the United States. Results show that…

  19. Dynamic Factor Models with Smooth Loadings for Analyzing the Term Structure of Interest Rates

    NARCIS (Netherlands)

    B. Jungbacker (Borus); S.J. Koopman (Siem Jan); M. van der Wel (Michel)

    2009-01-01

    textabstractWe propose a new approach to the modelling of the term structure of interest rates. We consider the general dynamic factor model and show how to impose smoothness restrictions on the factor loadings. We further present a statistical procedure based on Wald tests that can be used to find

  20. Partial Safety Factors and Target Reliability Level in Danish Structural Codes

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Hansen, J. O.; Nielsen, T. A.

    2001-01-01

    The partial safety factors in the newly revised Danish structural codes have been derived using a reliability-based calibration. The calibrated partial safety factors result in the same average reliability level as in the previous codes, but a much more uniform reliability level has been obtained...

  1. Exact diagonalization study of domain structures in integer filling factor quantum Hall ferromagnets

    Czech Academy of Sciences Publication Activity Database

    Rezayi, E. H.; Jungwirth, Tomáš; MacDonald, A. H.; Haldane, F. D. M.

    2003-01-01

    Roč. 67, č. 20 (2003), s. 201305-1 - 201305-4 ISSN 0163-1829 R&D Projects: GA ČR GA202/01/0754 Institutional research plan: CEZ:AV0Z1010914 Keywords : domain structure * integer filling factor * quantum Hall ferromagnets Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.962, year: 2003

  2. Factor Structure and Basic Psychometric Properties of the "Transition Assessment and Goal Generator"

    Science.gov (United States)

    Hennessey, Maeghan N.; Terry, Robert; Martin, James E.; McConnell, Amber E.; Willis, Donna M.

    2018-01-01

    We examined the theoretical factor structure fit and psychometric properties of the "Transition Assessment and Goal Generator" (TAGG). In the first study, 349 transition-aged students with disabilities, their special educators, and family members completed TAGG assessments, and using exploratory factor analysis (EFA)/confirmatory factor…

  3. The structure of psychopathology in adolescence : Replication of a general psychopathology factor in the TRAILS study

    NARCIS (Netherlands)

    Laceulle, O.M.; Vollebergh, W.A.M.; Ormel, J.

    2015-01-01

    This study aimed to replicate a study by Caspi and colleagues, which proposed that the structure of psychopathology is characterized by a general psychopathology factor, in addition to smaller internalizing and externalizing factors. Our study expanded the approach of the original by using

  4. Psychometric properties and factor structure of an L2 reading motivation questionnaire.

    Science.gov (United States)

    Kim, Hee-jung; Choi, Sunhee

    2014-01-01

    The purpose of this study is to investigate the psychometric properties and factor structure of a popular second language reading motivation questionnaire developed by Mori (2002). 550 first year high school students in Korea answered the 30-item questionnaire which consists of statements indicating different degrees of English reading motivation. Exploratory factor analysis was conducted with principal axis factoring and promax rotation, which yielded a four-factor solution. The factors included 'Intercultural and Intellectual Orientation', 'Reading Efficacy', 'Intrinsic Motivation', and 'Negative Attitudes'. The results supported the multidimensionality of the construct of L2 reading motivation, but could not replicate the nine factor structure which was originally proposed by Mori. The implications for further research on L2 reading motivation and development of a more valid L2 reading scale are discussed.

  5. Factor structure of the perfectionistic self-presentation scale in Korea.

    Science.gov (United States)

    Lee, Dong-Gwi; Suh, Hanna; Lee, Hee-Kyung

    2011-12-01

    This study explored the factor structure of the Korean version of the Perfectionistic Self-Presentation Scale, originally developed by Hewitt and colleagues in 2003 with three factors (Perfectionistic Self-promotion, Non-display of Imperfection, and Non-disclosure of Imperfection). In Study 1, a confirmatory factor analysis was performed on the Korean version with 27 items for 151 Korean college students, but the model fit was poor. Subsequently, an exploratory factor analysis was conducted, and the results yielded three factors as found in Hewitt, et al., yet with 20 items rather than the original 27 items. This new version had good internal consistency (Cronbach's alpha =.88); convergent validity estimate was established with a measure of self-presentation motivation. In Study 2, to support the structural validity of the Korean version, another confirmatory factor analysis was conducted with 203 Korean college students. The model fit was good, but a few amendments were made.

  6. An evaluation method for corrosion fatigue life of steel structure considering mechanical factors

    OpenAIRE

    Wang, Huili; Qin, Sifeng; Jiang, Tao

    2018-01-01

    Steel structures in corrosive environment are often subjected to coupling effect and damage caused by corrosion and fatigue. This paper proposed a new assessment method to study corrosion fatigue life of steel structure, including the effect of cyclic loading and corrosion damage. Based on mechanical factors, the corrosion depth of structure under cyclic loading at different time intervals was defined by a mathematical model for corrosion damage. A finite element model was established to calc...

  7. Factor structure of PTSD, and relation with gender in trauma survivors from India.

    Science.gov (United States)

    Charak, Ruby; Armour, Cherie; Elklit, Ask; Angmo, Disket; Elhai, Jon D; Koot, Hans M

    2014-01-01

    The factor structure of posttraumatic stress disorder (PTSD) has been extensively studied in Western countries. Some studies have assessed its factor structure in Asia (China, Sri Lanka, and Malaysia), but few have directly assessed the factor structure of PTSD in an Indian adult sample. Furthermore, in a largely patriarchal society in India with strong gender roles, it becomes imperative to assess the association between the factors of PTSD and gender. The purpose of the present study was to assess the factor structure of PTSD in an Indian sample of trauma survivors based on prevailing models of PTSD defined in the DSM-IV-TR (APA, 2000), and to assess the relation between PTSD factors and gender. The sample comprised of 313 participants (55.9% female) from Jammu and Kashmir, India, who had experienced a natural disaster (N=200) or displacement due to cross-border firing (N=113). Three existing PTSD models-two four-factor models (Emotional Numbing and Dysphoria), and a five-factor model (Dysphoric Arousal)-were tested using Confirmatory Factor Analysis with addition of gender as a covariate. The three competing models had similar fit indices although the Dysphoric Arousal model fit significantly better than Emotional Numbing and Dysphoria models. Gender differences were found across the factors of Re-experiencing and Anxious arousal. Findings indicate that the Dysphoric Arousal model of PTSD was the best model; albeit the fit indices of all models were fairly similar. Compared to males, females scored higher on factors of Re-experiencing and Anxious arousal. Gender differences found across two factors of PTSD are discussed in light of the social milieu in India.

  8. Factor structure of PTSD, and relation with gender in trauma survivors from India

    Science.gov (United States)

    Charak, Ruby; Armour, Cherie; Elklit, Ask; Angmo, Disket; Elhai, Jon D.; Koot, Hans M.

    2014-01-01

    Background The factor structure of posttraumatic stress disorder (PTSD) has been extensively studied in Western countries. Some studies have assessed its factor structure in Asia (China, Sri Lanka, and Malaysia), but few have directly assessed the factor structure of PTSD in an Indian adult sample. Furthermore, in a largely patriarchal society in India with strong gender roles, it becomes imperative to assess the association between the factors of PTSD and gender. Objective The purpose of the present study was to assess the factor structure of PTSD in an Indian sample of trauma survivors based on prevailing models of PTSD defined in the DSM-IV-TR (APA, 2000), and to assess the relation between PTSD factors and gender. Method The sample comprised of 313 participants (55.9% female) from Jammu and Kashmir, India, who had experienced a natural disaster (N=200) or displacement due to cross-border firing (N=113). Results Three existing PTSD models—two four-factor models (Emotional Numbing and Dysphoria), and a five-factor model (Dysphoric Arousal)—were tested using Confirmatory Factor Analysis with addition of gender as a covariate. The three competing models had similar fit indices although the Dysphoric Arousal model fit significantly better than Emotional Numbing and Dysphoria models. Gender differences were found across the factors of Re-experiencing and Anxious arousal. Conclusions Findings indicate that the Dysphoric Arousal model of PTSD was the best model; albeit the fit indices of all models were fairly similar. Compared to males, females scored higher on factors of Re-experiencing and Anxious arousal. Gender differences found across two factors of PTSD are discussed in light of the social milieu in India. PMID:25413575

  9. Factor structure of PTSD, and relation with gender in trauma survivors from India

    Directory of Open Access Journals (Sweden)

    Ruby Charak

    2014-11-01

    Full Text Available Background: The factor structure of posttraumatic stress disorder (PTSD has been extensively studied in Western countries. Some studies have assessed its factor structure in Asia (China, Sri Lanka, and Malaysia, but few have directly assessed the factor structure of PTSD in an Indian adult sample. Furthermore, in a largely patriarchal society in India with strong gender roles, it becomes imperative to assess the association between the factors of PTSD and gender. Objective: The purpose of the present study was to assess the factor structure of PTSD in an Indian sample of trauma survivors based on prevailing models of PTSD defined in the DSM-IV-TR (APA, 2000, and to assess the relation between PTSD factors and gender. Method: The sample comprised of 313 participants (55.9% female from Jammu and Kashmir, India, who had experienced a natural disaster (N=200 or displacement due to cross-border firing (N=113. Results: Three existing PTSD models—two four-factor models (Emotional Numbing and Dysphoria, and a five-factor model (Dysphoric Arousal—were tested using Confirmatory Factor Analysis with addition of gender as a covariate. The three competing models had similar fit indices although the Dysphoric Arousal model fit significantly better than Emotional Numbing and Dysphoria models. Gender differences were found across the factors of Re-experiencing and Anxious arousal. Conclusions: Findings indicate that the Dysphoric Arousal model of PTSD was the best model; albeit the fit indices of all models were fairly similar. Compared to males, females scored higher on factors of Re-experiencing and Anxious arousal. Gender differences found across two factors of PTSD are discussed in light of the social milieu in India.

  10. A combined structural dynamics approach identifies a putative switch in factor VIIa employed by tissue factor to initiate blood coagulation

    DEFF Research Database (Denmark)

    Olsen, Ole H; Rand, Kasper D; Østergaard, Henrik

    2007-01-01

    ) simulations and hydrogen/deuterium exchange (HX) mass spectrometry on free and TF-bound FVIIa. The differences in conformational dynamics from MD simulations are shown to be confined to regions of FVIIa observed to undergo structural stabilization as judged by HX experiments, especially implicating activation......Coagulation factor VIIa (FVIIa) requires tissue factor (TF) to attain full catalytic competency and to initiate blood coagulation. In this study, the mechanism by which TF allosterically activates FVIIa is investigated by a structural dynamics approach that combines molecular dynamics (MD...... stability of activation loop 3. Altogether, our findings strongly support an allosteric activation mechanism initiated by the stabilization of the Leu305{163}/Phe374{225} pair, which, in turn, stabilizes activation loop 3 and the S(1) and S(3) substrate pockets, the activation pocket, and N...

  11. Factor structure and psychometric properties of the brief illness perception questionnaire in Turkish cancer patients

    Directory of Open Access Journals (Sweden)

    Tuğba Karatas

    2017-01-01

    Full Text Available Objective: The main aim of this study was to investigate the factor structure and psychometric properties of the Brief Illness Perception Questionnaire (BIPQ in Turkish cancer patients. Methods: This methodological study involved 135 cancer patients. Statistical methods included confirmatory or exploratory factor analysis and Cronbach alpha coefficients for internal consistency. Results: The values of fit indices are within the acceptable range. The alpha coefficients for emotional illness representations, cognitive illness representations, and total scale are 0.83, 0.80, and 0.85, respectively. Conclusions: The results confirm the two-factor structure of the Turkish BIPQ and demonstrate its reliability and validity.

  12. Stable production of human insulin-like growth factor 1 (IGF-1) in the milk of hemi- and homozygous transgenic rabbits over several generations.

    Science.gov (United States)

    Zinovieva, N; Lassnig, C; Schams, D; Besenfelder, U; Wolf, E; Müller, S; Frenyo, L; Seregi, J; Müller, M; Brem, G

    1998-11-01

    One transgenic rabbit line was generated carrying a fusion gene consisting of the cDNA for human IGF-1 fused to a mammary gland specific expression cassette derived from bovine alpha-S1-casein sequences. Transgene expression was shown to be strictly tissue and lactation period specific. The transgenic rabbit line was bred for six generations. All transgenic animals showed stable production of biologically active IGF-1 over the generations and no apparent effect on the physiological or reproductive performance was observed. The absence of adverse effects on homozygous transgenic rabbits suggested the absence of insertional mutagenesis. Eight hemizygous transgenic offspring analysed produced on average 363 +/- 12 micrograms/ml (ranging from 223 +/- 61 to 484 +/- 39 micrograms/ml) mature human IGF-1 in their milk, whereas three homozygous animals produced on average 543 +/- 41 micrograms/ml (ranging from 360 +/- 15 to 678 +/- 80 micrograms/ml). Homozygous hulGF-1 females clearly showed a significantly increased production performance of the recombinant protein.

  13. Duplex structural differences and not 2′-hydroxyls explain the more stable binding of HIV-reverse transcriptase to RNA-DNA versus DNA-DNA

    OpenAIRE

    Olimpo, Jeffrey T.; DeStefano, Jeffrey J.

    2010-01-01

    Human immunodeficiency virus reverse transcriptase (HIV-RT) binds more stably in binary complexes with RNA–DNA versus DNA–DNA. Current results indicate that only the -2 and -4 RNA nucleotides (-1 hybridized to the 3′ recessed DNA base) are required for stable binding to RNA–DNA, and even a single RNA nucleotide conferred significantly greater stability than DNA–DNA. Replacing 2′- hydroxyls on pivotal RNA bases with 2′-O-methyls did not affect stability, indicating that interactions between hy...

  14. Specification of Architecture and Function of Actin Structures by Actin Nucleation Factors.

    Science.gov (United States)

    Skau, Colleen T; Waterman, Clare M

    2015-01-01

    The actin cytoskeleton is essential for diverse processes in mammalian cells; these processes range from establishing cell polarity to powering cell migration to driving cytokinesis to positioning intracellular organelles. How these many functions are carried out in a spatiotemporally regulated manner in a single cytoplasm has been the subject of much study in the cytoskeleton field. Recent work has identified a host of actin nucleation factors that can build architecturally diverse actin structures. The biochemical properties of these factors, coupled with their cellular location, likely define the functional properties of actin structures. In this article, we describe how recent advances in cell biology and biochemistry have begun to elucidate the role of individual actin nucleation factors in generating distinct cellular structures. We also consider how the localization and orientation of actin nucleation factors, in addition to their kinetic properties, are critical to their ability to build a functional actin cytoskeleton.

  15. Determining the number of factors to retain in an exploratory factor analysis using comparison data of known factorial structure.

    Science.gov (United States)

    Ruscio, John; Roche, Brendan

    2012-06-01

    Exploratory factor analysis (EFA) is used routinely in the development and validation of assessment instruments. One of the most significant challenges when one is performing EFA is determining how many factors to retain. Parallel analysis (PA) is an effective stopping rule that compares the eigenvalues of randomly generated data with those for the actual data. PA takes into account sampling error, and at present it is widely considered the best available method. We introduce a variant of PA that goes even further by reproducing the observed correlation matrix rather than generating random data. Comparison data (CD) with known factorial structure are first generated using 1 factor, and then the number of factors is increased until the reproduction of the observed eigenvalues fails to improve significantly. We evaluated the performance of PA, CD with known factorial structure, and 7 other techniques in a simulation study spanning a wide range of challenging data conditions. In terms of accuracy and robustness across data conditions, the CD technique outperformed all other methods, including a nontrivial superiority to PA. We provide program code to implement the CD technique, which requires no more specialized knowledge or skills than performing PA. (c) 2012 APA, all rights reserved

  16. Factor structure of self-reported clinical disorders and personality disorders : A review of the existing literature and a factor analytical study

    NARCIS (Netherlands)

    Bachrach, N.; Croon, M.A.; Bekker, M.H.J.

    2012-01-01

    Objectives The aim of this research is to add to the current understanding of the latent factor structure of personality disorders by performing a review of the existing literature (Study 1) and a factor analytical study on the factor structure and the relationship between self-reported Axis I and

  17. Panel Data with Cross-Sectional Dependence Characterized by a Multi-Level Factor Structure

    DEFF Research Database (Denmark)

    Rodríguez-Caballero, Carlos Vladimir

    A panel data model with a multi-level cross-sectional dependence is proposed. The factor structure is driven by top-level common factors as well as non-pervasive factors. I propose a simple method to filter out the full factor structure that overcomes limitations in standard procedures which may...... mix up both levels of unobservable factors and may hamper the identification of the model. The model covers both stationary and non-stationary cases and takes into account other relevant features that make the model well suited to the analysis of many types of time series frequently addressed...... in macroeconomics and finance. The model makes it possible to examine the time series and cross-sectional dynamics of variables allowing for a rich fractional cointegration analysis. A Monte Carlo simulation is conducted to examine the finite sample features of the suggested procedure. Findings indicate...

  18. Identification of the underlying factor structure of the Derriford Appearance Scale 24

    Directory of Open Access Journals (Sweden)

    Timothy P. Moss

    2015-07-01

    Full Text Available Background. The Derriford Appearance Scale24 (DAS24 is a widely used measure of distress and dysfunction in relation to self-consciousness of appearance. It has been used in clinical and research settings, and translated into numerous European and Asian languages. Hitherto, no study has conducted an analysis to determine the underlying factor structure of the scale.Methods. A large (n = 1,265 sample of community and hospital patients with a visible difference were recruited face to face or by post, and completed the DAS24.Results. A two factor solution was generated. An evaluation of the congruence of the factor solutions on each of the the hospital and the community samples using Tucker’s Coefficient of Congruence (rc = .979 and confirmatory factor analysis, which demonstrated a consistent factor structure. A main factor, general self consciousness (GSC, was represented by 18 items. Six items comprised a second factor, sexual and body self-consciousness (SBSC. The SBSC scale demonstrated greater sensitivity and specificity in identifying distress for sexually significant areas of the body.Discussion. The factor structure of the DAS24 facilitates a more nuanced interpretation of scores using this scale. Two conceptually and statistically coherent sub-scales were identified. The SBSC sub-scale offers a means of identifying distress and dysfunction around sexually significant areas of the body not previously possible with this scale.

  19. Testing the factor structure of the beliefs about language learning inventory.

    Science.gov (United States)

    Hsiao, Tsung-Yuan; Chiang, Steve

    2010-12-01

    This preliminary study examined the factor structure of the Beliefs About Language Learning Inventory in two samples of about 750 college students of English as a foreign language in Taiwan. Results of confirmatory factor analysis lend partial support to Horwitz's theoretical five-factor belief model. Subsequent exploratory and confirmatory factor analyses of data show that a four-factor model represented by only 12 items performed better than other models both theoretically and empirically. This model consists of two dimensions already theorized in the inventory: Difficulty of Language Learning and Foreign Language Aptitude, and two newly interpreted dimensions, Importance of Spoken Language and Analytical Approaches to Language Learning. Although this four-factor model could be replicated in an independent sample, the factors are not reliable, suggesting the need to search for a more representative set of beliefs to tap specific aspects of language learning.

  20. Multilevel Factor Structure and Concurrent Validity of the Teacher Version of the Authoritative School Climate Survey.

    Science.gov (United States)

    Huang, Francis L; Cornell, Dewey G; Konold, Timothy; Meyer, Joseph P; Lacey, Anna; Nekvasil, Erin K; Heilbrun, Anna; Shukla, Kathan D

    2015-12-01

    School climate is well recognized as an important influence on student behavior and adjustment to school, but there is a need for theory-guided measures that make use of teacher perspectives. Authoritative school climate theory hypothesizes that a positive school climate is characterized by high levels of disciplinary structure and student support. A teacher version of the Authoritative School Climate Survey (ASCS) was administered to a statewide sample of 9099 7th- and 8th-grade teachers from 366 schools. The study used exploratory and multilevel confirmatory factor analyses (MCFA) that accounted for the nested data structure and allowed for the modeling of the factor structures at 2 levels. Multilevel confirmatory factor analyses conducted on both an exploratory (N = 4422) and a confirmatory sample (N = 4677) showed good support for the factor structures investigated. Factor correlations at 2 levels indicated that schools with greater levels of disciplinary structure and student support had higher student engagement, less teasing and bullying, and lower student aggression toward teachers. The teacher version of the ASCS can be used to assess 2 key domains of school climate and associated measures of student engagement and aggression toward peers and teachers. © 2015, American School Health Association.

  1. Factor analyses of the Hospital Anxiety and Depression Scale: a Bayesian structural equation modeling approach.

    Science.gov (United States)

    Fong, Ted Chun Tat; Ho, Rainbow Tin Hung

    2013-12-01

    The latent structure of the Hospital Anxiety and Depression Scale (HADS) has caused inconsistent results in the literature. The HADS is frequently analyzed via maximum likelihood confirmatory factor analysis (ML-CFA). However, the overly restrictive assumption of exact zero cross-loadings and residual correlations in ML-CFA can lead to poor model fits and distorted factor structures. This study applied Bayesian structural equation modeling (BSEM) to evaluate the latent structure of the HADS. Three a priori models, the two-factor, three-factor, and bifactor models, were investigated in a Chinese community sample (N = 312) and clinical sample (N = 198) using ML-CFA and BSEM. BSEM specified approximate zero cross-loadings and residual correlations through the use of zero-mean, small-variance informative priors. The model comparison was based on the Bayesian information criterion (BIC). Using ML-CFA, none of the three models provided an adequate fit for either sample. The BSEM two-factor model with approximate zero cross-loadings and residual correlations fitted both samples well with the lowest BIC of the three models and displayed a simple and parsimonious factor-loading pattern. The study demonstrated that the two-factor structure fitted the HADS well, suggesting its usefulness in assessing the symptoms of anxiety and depression in clinical practice. BSEM is a sophisticated and flexible statistical technique that better reflects substantive theories and locates the source of model misfit. Future use of BSEM is recommended to evaluate the latent structure of other psychological instruments.

  2. An Evaluation of the Factor Structure of the Change Assessment Inventory for Domestic Violence among Korean Batterers

    Science.gov (United States)

    Kim, Jae Yop; Song, Ah Young

    2009-01-01

    Objective: Results of testing the original four-factor structure of the URICA-DV as well as two three-factor structures in prior researches is presented to investigate alternative structures suitable for Korean batterers. Method: This study developed the URICA-DV Korean Version and sought the most appropriate structure for a Korean context. The…

  3. A systematic review of the main factors that determine agility in sport using structural equation modeling

    Directory of Open Access Journals (Sweden)

    Hojka Vladimir

    2016-09-01

    Full Text Available While tests of basic motor abilities such as speed, maximum strength or endurance are well recognized, testing of complex motor functions such as agility remains unresolved in current literature. Therefore, the aim of this review was to evaluate which main factor or factor structures quantitatively determine agility. In methodological detail, this review focused on research that explained or described the relationships between latent variables in a factorial model of agility using approaches such as principal component analysis, factor analysis and structural equation modeling. Four research studies met the defined inclusion criteria. No quantitative empirical research was found that tried to verify the quality of the whole suggested model of the main factors determining agility through the use of a structural equation modeling (SEM approach or a confirmatory factor analysis. From the whole structure of agility, only change of direction speed (CODS and some of its subtests were appropriately analyzed. The combination of common CODS tests is reliable and useful to estimate performance in sub-elite athletes; however, for elite athletes, CODS tests must be specific to the needs of a particular sport discipline. Sprinting and jumping tests are stronger factors for CODS than explosive strength and maximum strength tests. The authors suggest the need to verify the agility factorial model by a second generation data analysis technique such as SEM.

  4. A systematic review of the main factors that determine agility in sport using structural equation modeling.

    Science.gov (United States)

    Hojka, Vladimir; Stastny, Petr; Rehak, Tomas; Gołas, Artur; Mostowik, Aleksandra; Zawart, Marek; Musálek, Martin

    2016-09-01

    While tests of basic motor abilities such as speed, maximum strength or endurance are well recognized, testing of complex motor functions such as agility remains unresolved in current literature. Therefore, the aim of this review was to evaluate which main factor or factor structures quantitatively determine agility. In methodological detail, this review focused on research that explained or described the relationships between latent variables in a factorial model of agility using approaches such as principal component analysis, factor analysis and structural equation modeling. Four research studies met the defined inclusion criteria. No quantitative empirical research was found that tried to verify the quality of the whole suggested model of the main factors determining agility through the use of a structural equation modeling (SEM) approach or a confirmatory factor analysis. From the whole structure of agility, only change of direction speed (CODS) and some of its subtests were appropriately analyzed. The combination of common CODS tests is reliable and useful to estimate performance in sub-elite athletes; however, for elite athletes, CODS tests must be specific to the needs of a particular sport discipline. Sprinting and jumping tests are stronger factors for CODS than explosive strength and maximum strength tests. The authors suggest the need to verify the agility factorial model by a second generation data analysis technique such as SEM.

  5. Reformulation of the Children's Eating Attitudes Test (ChEAT): factor structure and scoring method in a non-clinical population.

    Science.gov (United States)

    Anton, S D; Han, H; Newton, R L; Martin, C K; York-Crowe, E; Stewart, T M; Williamson, D A

    2006-12-01

    The primary aims of this study were to empirically test the factor structure of the Children's Eating Attitudes Test (ChEAT) through both exploratory and confirmatory factor analyses and to interpret the factor structure of the ChEAT within the context of a new scoring method. The ChEAT was administered to 728 children in the 2nd through 6th grades (from five schools) at two different time points. Exactly half the students were male and half were female. To the best of our knowledge, this is the first study to empirically test the merits of an alternative 6-point scoring system as compared to the traditionally used 4-point scoring system. With the new scoring procedure, the skewness for all factor scores decreased, which resulted in increased variance in the item scores, as well as the total ChEAT score. Since the internal consistency of two factors in a recently proposed model was not acceptable (ChEAT reported by previous investigations. Intercorrelations among the factors suggested three higher order constructs. These findings indicate that the ChEAT subscales may be sufficiently stable to allow use in non-clinical samples of children.

  6. The Three-Dimensional Solution Structure of the Src Homology Domain-2 of the Growth Factor Receptor-Bound Protein-2

    International Nuclear Information System (INIS)

    Senior, Mary M.; Frederick, Anne F.; Black, Stuart; Murgolo, Nicholas J.; Perkins, Louise M.; Wilson, Oswald; Snow, Mark E.; Wang Yusen

    1998-01-01

    A set of high-resolution three-dimensional solution structures of the Src homology region-2 (SH2) domain of the growth factor receptor-bound protein-2 was determined using heteronuclear NMR spectroscopy. The NMR data used in this study were collected on a stable monomeric protein solution that was free of protein aggregates and proteolysis. The solution structure was determined based upon a total of 1439 constraints, which included 1326 nuclear Overhauser effect distance constraints, 70 hydrogen bond constraints, and 43 dihedral angle constraints. Distance geometry-simulated annealing calculations followed by energy minimization yielded a family of 18 structures that converged to a root-mean-square deviation of 1.09 A for all backbone atoms and 0.40 A for the backbone atoms of the central β-sheet. The core structure of the SH2 domain contains an antiparallel β-sheet flanked by two parallel α-helices displaying an overall architecture that is similar to other known SH2 domain structures. This family of NMR structures is compared to the X-ray structure and to another family of NMR solution structures determined under different solution conditions

  7. "Parallel factor analysis of multi-excitation ultraviolet resonance Raman spectra for protein secondary structure determination".

    Science.gov (United States)

    Oshokoya, Olayinka O; JiJi, Renee D

    2015-09-10

    Protein secondary structural analysis is important for understanding the relationship between protein structure and function, or more importantly how changes in structure relate to loss of function. The structurally sensitive protein vibrational modes (amide I, II, III and S) in deep-ultraviolet resonance Raman (DUVRR) spectra resulting from the backbone C-O and N-H vibrations make DUVRR a potentially powerful tool for studying secondary structure changes. Experimental studies reveal that the position and intensity of the four amide modes in DUVRR spectra of proteins are largely correlated with the varying fractions of α-helix, β-sheet and disordered structural content of proteins. Employing multivariate calibration methods and DUVRR spectra of globular proteins with varying structural compositions, the secondary structure of a protein with unknown structure can be predicted. A disadvantage of multivariate calibration methods is the requirement of known concentration or spectral profiles. Second-order curve resolution methods, such as parallel factor analysis (PARAFAC), do not have such a requirement due to the "second-order advantage." An exceptional feature of DUVRR spectroscopy is that DUVRR spectra are linearly dependent on both excitation wavelength and secondary structure composition. Thus, higher order data can be created by combining protein DUVRR spectra of several proteins collected at multiple excitation wavelengths to give multi-excitation ultraviolet resonance Raman data (ME-UVRR). PARAFAC has been used to analyze ME-UVRR data of nine proteins to resolve the pure spectral, excitation and compositional profiles. A three factor model with non-negativity constraints produced three unique factors that were correlated with the relative abundance of helical, β-sheet and poly-proline II dihedral angles. This is the first empirical evidence that the typically resolved "disordered" spectrum represents the better defined poly-proline II type structure

  8. The influence of environmental, biotic and spatial factors on diatom metacommunity structure in Swedish headwater streams.

    Directory of Open Access Journals (Sweden)

    Emma Göthe

    Full Text Available Stream assemblages are structured by a combination of local (environmental filtering and biotic interactions and regional factors (e.g., dispersal related processes. The relative importance of environmental and spatial (i.e., regional factors structuring stream assemblages has been frequently assessed in previous large-scale studies, but biotic predictors (potentially reflecting local biotic interactions have rarely been included. Diatoms may be useful for studying the effect of trophic interactions on community structure since: (1 a majority of experimental studies shows significant grazing effects on diatom species composition, and (2 assemblages can be divided into guilds that have different susceptibility to grazing. We used a dataset from boreal headwater streams in south-central Sweden (covering a spatial extent of ∼14000 km(2, which included information about diatom taxonomic composition, abundance of invertebrate grazers (biotic factor, environmental (physicochemical and spatial factors (obtained through spatial eigenfunction analyses. We assessed the relative importance of environmental, biotic, and spatial factors structuring diatom assemblages, and performed separate analyses on different diatom guilds. Our results showed that the diatom assemblages were mainly structured by environmental factors. However, unique spatial and biological gradients, specific to different guilds and unrelated to each other, were also evident. We conclude that biological predictors, in combination with environmental and spatial variables, can reveal a more complete picture of the local vs. regional control of species assemblages in lotic environments. Biotic factors should therefore not be overlooked in applied research since they can capture additional local control and therefore increase accuracy and performance of predictive models. The inclusion of biotic predictors did, however, not significantly influence the unique fraction explained by spatial

  9. The Influence of Environmental, Biotic and Spatial Factors on Diatom Metacommunity Structure in Swedish Headwater Streams

    Science.gov (United States)

    Göthe, Emma; Angeler, David G.; Gottschalk, Steffi; Löfgren, Stefan; Sandin, Leonard

    2013-01-01

    Stream assemblages are structured by a combination of local (environmental filtering and biotic interactions) and regional factors (e.g., dispersal related processes). The relative importance of environmental and spatial (i.e., regional) factors structuring stream assemblages has been frequently assessed in previous large-scale studies, but biotic predictors (potentially reflecting local biotic interactions) have rarely been included. Diatoms may be useful for studying the effect of trophic interactions on community structure since: (1) a majority of experimental studies shows significant grazing effects on diatom species composition, and (2) assemblages can be divided into guilds that have different susceptibility to grazing. We used a dataset from boreal headwater streams in south-central Sweden (covering a spatial extent of ∼14000 km2), which included information about diatom taxonomic composition, abundance of invertebrate grazers (biotic factor), environmental (physicochemical) and spatial factors (obtained through spatial eigenfunction analyses). We assessed the relative importance of environmental, biotic, and spatial factors structuring diatom assemblages, and performed separate analyses on different diatom guilds. Our results showed that the diatom assemblages were mainly structured by environmental factors. However, unique spatial and biological gradients, specific to different guilds and unrelated to each other, were also evident. We conclude that biological predictors, in combination with environmental and spatial variables, can reveal a more complete picture of the local vs. regional control of species assemblages in lotic environments. Biotic factors should therefore not be overlooked in applied research since they can capture additional local control and therefore increase accuracy and performance of predictive models. The inclusion of biotic predictors did, however, not significantly influence the unique fraction explained by spatial factors

  10. The factor structure for positive and negative symptoms in South African Xhosa patients with schizophrenia.

    Science.gov (United States)

    Emsley, R A; Niehaus, D J; Mbanga, N I; Oosthuizen, P P; Stein, D J; Maritz, J S; Pimstone, S N; Hayden, M R; Laurent, C; Deleuze, J F; Mallet, J

    2001-03-01

    Most studies investigating the symptom dimensions of schizophrenia utilising the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS) favour a three factor model. This study sought to investigate the factor structure of both the global and individual items of the SANS and SAPS in a large sample of South African Xhosa patients with schizophrenia. A total of 422 subjects participated. Both principal components and factor analytical procedures were applied. For the global items, a two-factor solution representing positive and negative symptoms accounted for 59.9% of the variance. Alternatively, the three-dimensional model of negative, psychotic and disorganisation factors was supported by a five-factor solution if the more heterogeneous items of attention and alogia were ignored. Analysis of the individual items yielded a five-factor solution with the negative symptoms splitting into diminished expression and disordered relating, and the positive symptoms separating into factors for psychosis, thought disorder and bizarre behaviour. Our findings are very similar to those from other parts of the world, providing evidence that the factor structure for the symptoms of schizophrenia is relatively resistant to cultural influences. This is particularly true for negative symptoms.

  11. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  12. Stable Boundary Layer Issues

    NARCIS (Netherlands)

    Steeneveld, G.J.

    2012-01-01

    Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The

  13. Evolutionary Stable Strategy

    Indian Academy of Sciences (India)

    IAS Admin

    After Maynard-Smith and Price [1] mathematically derived why a given behaviour or strategy was adopted by a certain proportion of the population at a given time, it was shown that a strategy which is currently stable in a population need not be stable in evolutionary time (across generations). Additionally it was sug-.

  14. Synthesis and characterization of highly efficient and stable Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt ternary hybrid structure

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Jiatao; Liu, Lin; Niu, Tongjun; Sun, Xiaosong, E-mail: sunxs@scu.edu.cn

    2017-05-01

    Highlights: • Visible-light-driven Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt photocatalysts were prepared. • Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt showed highly efficient and stable photocatalystic activity. • The photocatalytic mechanism of Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt composite was given. - Abstract: Ag{sub 3}PO{sub 4} is an excellent photocatalyst with high efficiency and quantum yield, but suffers from the fast recombination of photogenerated electron-hole pairs and photo-corrosion. Hereby, the highly efficient and stable visible-light-driven Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt photocatalyst were prepared via a three-step wet chemical approach. The as-prepared Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt composite was characterized by X-ray diffraction, US-vis diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, photoluminescence spectra and transient photocurrent as well. Comparing with single Pr{sub 6}O{sub 11} or Ag{sub 3}PO{sub 4}, the prepared Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt composite exhibited much higher photocatalytic activity and stability for the degradation of Rhodamine B under visible light irradiation (>420 nm). The enhanced photocatalytic performance of Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt composite has been attributed to the efficient separation of photo-generated electron-hole pairs through a scheme system composed of Pr{sub 6}O{sub 11,} Ag{sub 3}PO{sub 4} and Pt.

  15. The Structure of Genetic and Environmental Risk Factors for DSM-IV Personality Disorders

    Science.gov (United States)

    Kendler, Kenneth S.; Aggen, Steven H.; Czajkowski, Nikolai; Røysamb, Espen; Tambs, Kristian; Torgersen, Svenn; Neale, Michael C.; Reichborn-Kjennerud, Ted

    2009-01-01

    Context Although both genetic and environmental factors affect risk of individual personality disorders (PDs), we know little of how they contribute to the pattern of comorbidity between the PDs in the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (DSM-IV). Objective To clarify the structure of the genetic and environmental risk factors for the 10 DSM-IV PDs. Design Assessment of PDs at personal interview and multivariate twin modeling with the Mx program. Setting General community. Participants A total of 2794 young adult members of the Norwegian Institute of Public Health Twin Panel. Main Outcome Measure Number of endorsed criteria for the 10 DSM-IV PDs. Results The best-fit multivariate twin model required 3 genetic and 3 individual-specific environmental factors and genetic and individual-specific factors unique to each PD. The first genetic factor had high loadings on PDs from all 3 clusters including paranoid, histrionic, borderline, narcissistic, dependent, and obsessive-compulsive. The second genetic factor had substantial loadings only on borderline and antisocial PD. The third genetic factor had high loadings only on schizoid and avoidant PD. Several PDs had substantial disorder-specific genetic risk factors. The first, second, and third individual-specific environmental factors had high loadings on the cluster B, A, and C PDs, respectively, with 1 exception: obsessive-compulsive PD loaded with cluster B and not cluster C PDs. Conclusions Genetic risk factors for DSM-IV PDs do not reflect the cluster A, B, and C typology. Rather, 1 genetic factor reflects a broad vulnerability to PD pathology and/or negative emotionality. The 2 other genetic factors are more specific and reflect high impulsivity/low agreeableness and introversion. Unexpectedly, the cluster A, B, and C typology is well reflected in the structure of environmental risk factors, suggesting that environmental experiences may be responsible for the tendency of cluster A

  16. The factor structure of Lithuanian personality-descriptive adjectives of the highest frequency of use.

    Science.gov (United States)

    Livaniene, Vitalija; De Raad, Boele

    2017-12-01

    We developed the Lithuanian taxonomy of personality traits according to the psycho-lexical approach. This was done in two studies. First, trait descriptive terms were selected from a Lithuanian dictionary. This selection led to a list of 435 personality-relevant adjectives was thus collected. This list was reduced to the more useful terms and ultimately led to the 194 most frequently used trait adjectives. Second, self-ratings from 212 participants were collected on both those 194 terms and on the 44-item BFI. Principal Components Analysis followed by Varimax rotation was applied on the collected ratings, and also on the ratings after ipsatization. For both these types of analysis structures with two up to seven factors were discussed. Each of the structures was also related to the five BFI-scales. The slightly clearer structure was found in the ipsatized ratings, in which clear support was found for the two-factor model (with Dynamism and Social Propriety), for the three-factor model (Dynamism, Affiliation and Order). A five-factor solution was fully presented with the Big Five factors Extraversion, Agreeableness and Conscientiousness and with a factor that had Intellect traits on the one pole and Neurotic traits on the other, and finally a factor called Toughness. © 2016 International Union of Psychological Science.

  17. Social cognition in schizophrenia: Factor structure of emotion processing and theory of mind.

    Science.gov (United States)

    Browne, Julia; Penn, David L; Raykov, Tenko; Pinkham, Amy E; Kelsven, Skylar; Buck, Benjamin; Harvey, Philip D

    2016-08-30

    Factor analytic studies examining social cognition in schizophrenia have yielded inconsistent results most likely due to the varying number and quality of measures. With the recent conclusion of Phase 3 of the Social Cognition Psychometric Evaluation (SCOPE) Study, the most psychometrically sound measures of social cognition have been identified. Therefore, the aims of the present study were to: 1) examine the factor structure of social cognition in schizophrenia through the utilization of psychometrically sound measures, 2) examine the stability of the factor structure across two study visits, 3) compare the factor structure of social cognition in schizophrenia to that in healthy controls, and 4) examine the relationship between the factors and relevant outcome measures including social functioning and symptoms. Results supported a one-factor model for the patient and healthy control samples at both visits. This single factor was significantly associated with negative symptoms in the schizophrenia sample and with social functioning in both groups at both study visits. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Applying total interpretive structural modeling to study factors affecting construction labour productivity

    Directory of Open Access Journals (Sweden)

    Sayali Shrikrishna Sandbhor

    2014-03-01

    Full Text Available Construction sector has always been dependent on manpower. Most of the activities carried out on any construction site are labour intensive. Since productivity of any project depends directly on productivity of labour, it is a prime responsibility of the employer to enhance labour productivity. Measures to improve the same depend on analysis of positive and negative factors affecting productivity. Major attention should be given to factors that decrease the productivity of labour. Factor analysis thus is an integral part of any study aiming to improve productivity.  Interpretive structural modeling is a methodology for identifying and summarizing relationships among factors which define an issue or problem. It provides a means to arrange the factors in an order as per their complexity. This study attempts to use the latest version of interpretive structural modeling i.e. total interpretive structural modeling to analyze factors negatively affecting construction labour productivity. It establishes interpretive relationship among these factors facilitating improvement in the overall productivity of construction site.

  19. The factor structure of the metabolic syndrome in obese individuals with binge eating disorder.

    Science.gov (United States)

    Udo, Tomoko; McKee, Sherry A; White, Marney A; Masheb, Robin M; Barnes, Rachel D; Grilo, Carlos M

    2014-02-01

    Metabolic syndrome (MetS) is strongly linked with cardiovascular disease and type-II diabetes, but there has been debate over which metabolic measures constitute MetS. Obese individuals with binge eating disorder (BED) are one of the high risk populations for developing MetS due to their excess weight and maladaptive eating patterns, yet, the clustering patterns of metabolic measures have not been examined in this patient group. 347 adults (71.8% women) were recruited for treatment studies for obese individuals with BED. We used the VARCLUS procedure in the Statistical Analysis System (SAS) to investigate the clustering pattern of metabolic risk measures. The analysis yielded four factors: obesity (body-mass-index [BMI] and waist circumference), lipids (HDL and triglycerides), blood pressure (systolic and diastolic blood pressure), and glucose regulation (fasting serum glucose and Hb1Ac). The four factors accounted for 84% of the total variances, and variances explained by each factor were not substantially different. There was no inter-correlation between the four factors. Subgroup analyses by sex and by race (Caucasian vs. African American) yielded the same four-factor structure. The factor structure of MetS in obese individuals with BED is not different from those found in normative population studies. This factor structure may be applicable to the diverse population. © 2013.

  20. Followee recommendation in microblog using matrix factorization model with structural regularization.

    Science.gov (United States)

    Yu, Yan; Qiu, Robin G

    2014-01-01

    Microblog that provides us a new communication and information sharing platform has been growing exponentially since it emerged just a few years ago. To microblog users, recommending followees who can serve as high quality information sources is a competitive service. To address this problem, in this paper we propose a matrix factorization model with structural regularization to improve the accuracy of followee recommendation in microblog. More specifically, we adapt the matrix factorization model in traditional item recommender systems to followee recommendation in microblog and use structural regularization to exploit structure information of social network to constrain matrix factorization model. The experimental analysis on a real-world dataset shows that our proposed model is promising.

  1. Sum rules for four-spinon dynamic structure factor in XXX model

    International Nuclear Information System (INIS)

    Si Lakhal, B.; Abada, A.

    2005-01-01

    In the context of the antiferromagnetic spin 12 Heisenberg quantum spin chain (XXX model), we estimate the contribution of the exact four-spinon dynamic structure factor S 4 by calculating a number of sum rules the total dynamic structure factor S is known to satisfy exactly. These sum rules are: the static susceptibility, the integrated intensity, the total integrated intensity, the first frequency moment and the nearest-neighbor correlation function. We find that the contribution of S 4 is between 1% and 2.5%, depending on the sum rule, whereas the contribution of the exact two-spinon dynamic structure factor S 2 is between 70% and 75%. The calculations are numerical and Monte Carlo based. Good statistics are obtained

  2. Partial dynamic structure factors in Ni62Nb38 metallic glass

    International Nuclear Information System (INIS)

    Syrykh, G.F.; Khlopkin, M.N.; Zemlyanov, M.G.; Ivanov, A.S.; Schober, H.

    2002-01-01

    The total dynamic structure factors S(Q,E) in three Ni 62 Nb 38 samples with different isotope content were investigated by inelastic neutron scattering, over a range of momentum and energy transfer: Q=0.5-5 A -1 and E=1-40 meV at the IN6 spectrometer (ILL, Grenoble, France). According to the Ashcroft-Langreth formalism, the partial dynamic structure factors S NiNi (Q,E), S NbNb (Q,E) and S NiNb (Q,E) were reconstructed. It is the first experimental observation showing the existence of collective vibrational excitations in the Ni 62 Nb 38 metallic glass system at a partial dynamic structure factor level. (orig.)

  3. Three-factor structure for Epistemic Belief Inventory: A cross-validation study.

    Directory of Open Access Journals (Sweden)

    Francisco Leal-Soto

    Full Text Available Research on epistemic beliefs has been hampered by lack of validated models and measurement instruments. The most widely used instrument is the Epistemological Questionnaire, which has been criticized for validity, and it has been proposed a new instrument based in the Epistemological Questionnaire: the Epistemic Belief Inventory. The Spanish-language version of Epistemic Belief Inventory was applied to 1,785 Chilean high school students. Exploratory and confirmatory factor analyses in independent subsamples were performed. A three factor structure emerged and was confirmed. Reliability was comparable to other studies, and the factor structure was invariant among randomized subsamples. The structure that was found does not replicate the one proposed originally, but results are interpreted in light of embedded systemic model of epistemological beliefs.

  4. Two stable steady states in the Hodgkin-Huxley axons

    OpenAIRE

    Aihara, K.; Matsumoto, G.

    1983-01-01

    Two stable steady states were found in the numerical solution of the Hodgkin-Huxley equations for the intact squid axon bathed in potassium-rich sea water with an externally applied inward current. Under the conditions the two stable steady-states exist, the Hodgkin-Huxley equations have a complex bifurcation structure including, in addition to the two stable steady-states, a stable limit cycle, two unstable equilibrium points, and one asymptotically stable equilibrium point. It was also conc...

  5. Human ciliary neurotrophic factor-overexpressing stable bone marrow stromal cells in the treatment of a rat model of traumatic spinal cord injury.

    Science.gov (United States)

    Abbaszadeh, Hojjat-Allah; Tiraihi, Taki; Noori-Zadeh, Ali; Delshad, Ali Reza; Sadeghizade, Majid; Taheri, Taher

    2015-07-01

    Traumatic injury to the central nervous system (CNS) often causes motor dysfunctions. However, because of the CNS complexity and variability in the clinical presentations, efforts to repair damaged CNS tissue and restoring its functions are particularly demanding. On the other hand, recent progress in the regenerative therapy field have led to novel approaches for the treatment of traumatic CNS injury and renewed hopes to overcome the obstacles. It appears that the balance between neurite re-growth-inhibiting and neurite re-growth-inducing molecules determines the axonal re-growth fate. Neurotrophic factors can tilt this balance and indeed promote cell survival and axonal re-growth over neurodegeneration. One of the promising neurotrophic factors in this field is ciliary neurotrophic factor (CNTF). We transfected rat bone marrow stromal cells with a mammalian expression vector-inserted human CNTF gene through the use of a non-viral method to prepare human CNTF-overexpressing stem cells under ex vivo conditions. We transplanted these modified cells to the rat model of spinal cord traumatic injury to explore functional recovery after contusion induction. Our data from immunocytochemistry and behavioral tests showed that such cells can act as a powerful potential approach to treat traumatic CNS injuries because these modified cells improved the behavioral test scores in the rat model of spinal cord injury. CNTF-overexpressing bone marrow stromal cells can ameliorate spinal cord traumatic injury and can be used in the treatment of traumatic CNS injuries in the near future. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  6. Trends in Risk Factors and Treatments in Patients With Stable Ischemic Heart Disease Seen at Cardiology Clinics Between 2006 and 2014.

    Science.gov (United States)

    Cordero, Alberto; Galve, Enrique; Bertomeu-Martínez, Vicente; Bueno, Héctor; Fácila, Lorenzo; Alegría, Eduardo; Cequier, Ángel; Ruiz, Emilio; González-Juanatey, José Ramón

    2016-04-01

    Chronic ischemic heart disease is the most prevalent of all cardiovascular diseases. Patients are at high risk of complications. In recent decades, changes may have occurred in the clinical characteristics of the disease, its treatment and control of risk factors. A direct comparison of 2 national registries of patients with chronic ischemic heart disease carried out in 2006 (n=1583) and 2014 (n=1110). We observed statistically significant differences between the 2 registries, with a higher percentage of men and smokers in the 2014 registry, but a lower prevalence of diabetes mellitus and hypertension. Heart failure and stroke were more prevalent in the 2006 registry. Patients in the 2014 registry had better results for lipid profile, blood glucose, creatinine, and glomerular filtration rate. We observed higher use of recommended drugs for secondary prevention and an increased percentage of patients receiving optimal medical therapy, from 32.5% to 49.5% (P<.01). Use of high-intensity statin doses also increased from 10.5% to 42.8% (P<.01). We found better control of some risk factors (improved dyslipidemia, heart rate, and blood glucose in patients with diabetes) but worse blood pressure control. The clinical profile of patients with chronic ischemic heart disease is similar in the 2 registries. There has been an improvement in patients' medical therapy and dyslipidemia control, blood glucose, and heart rate, but there is still much room for improvement in the control of other cardiovascular risk factors. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  7. Applicability study of the structure-factor phase method for determining the polarity of binary semiconductors.

    Science.gov (United States)

    Cao, Jiefeng; Guo, Chao; Zou, Huamin

    2013-12-01

    The structure-factor phase method of convergent-beam electron diffraction (CBED) has been widely applied as an effective tool in determining the polarity of binary compound materials, for example, the typical sphalerite material, GaAs. However, its validity on other polar materials is still unknown. In this paper we extensively investigated its potential applicability onto 11 AB-type semiconductors by dynamical simulations of CBED. Two key factors during the simulation, the difference between A and B atomic numbers and the sample thickness, are discussed in detail. It was found that this method is efficient to determine the polarity for a sphalerite structure under certain conditions, and, reversely, limited to determine the polarity for a wurtzite structure even though it is very similar to the sphalerite structure.

  8. Geometrical structure factors of the crystal-field coefficients in ionic and metallic cubic compounds

    International Nuclear Information System (INIS)

    Adam, S.; Adam, G.; Corciovei, A.

    1977-01-01

    The crystal-field Hamiltonian for cubic compounds is brought into the standard form of the crystal-field theory by a general symmetrization technique which uses point group considerations only. The obtained crystal-field coefficients are expressed as products between those given by Hutchings and some geometrical structure factors, which include the relative contribution of all the neighbouring ions to the crystal-field. Assuming point charges in vacuum, numerical values are reported for the geometrical structure factors of several cubic structures and significant departures from Hutchings' results are found in some cases. Then, the screening effect of the conduction electrons in cubic metallic structures is investigated supposing a screened Coulomb interionic potential. (author)

  9. New insight in the structural features of haloadaptation in α-amylases from halophilic Archaea following homology modeling strategy: folded and stable conformation maintained through low hydrophobicity and highly negative charged surface

    Science.gov (United States)

    Zorgani, Mohamed Amine; Patron, Kevin; Desvaux, Mickaël

    2014-07-01

    Proteins from halophilic archaea, which live in extreme saline conditions, have evolved to remain folded, active and stable at very high ionic strengths. Understanding the mechanism of haloadaptation is the first step toward engineering of halostable biomolecules. Amylases are one of the main enzymes used in industry. Yet, no three-dimensional structure has been experimentally resolved for α-amylases from halophilic archaea. In this study, homology structure modeling of α-amylases from the halophilic archaea Haloarcula marismortui, Haloarcula hispanica, and Halalkalicoccus jeotgali were performed. The resulting models were subjected to energy minimization, evaluation, and structural analysis. Calculations of the amino acid composition, salt bridges and hydrophobic interactions were also performed and compared to a set of non-halophilic counterparts. It clearly appeared that haloarchaeal α-amylases exhibited lower propensities for helix formation and higher propensities for coil-forming regions. Furthermore, they could maintain a folded and stable conformation in high salt concentration through highly negative charged surface with over representation of acidic residues, especially Asp, and low hydrophobicity with increase of salt bridges and decrease in hydrophobic interactions on the protein surface. This study sheds some light on the stability of α-amylases from halophilic archaea and provides strong basis not only to understand haloadaptation mechanisms of proteins in microorganisms from hypersalines environments but also for biotechnological applications.

  10. The Factor Structure and Validity of the Persian Version of the Baumrind Parenting Style Inventory

    Directory of Open Access Journals (Sweden)

    اصغر مینائی

    2017-06-01

    Full Text Available In this study, the factor structure and validity of the Persian version of the Baumrind parenting style inventory were evaluated among 576 mothers of elementary school students in Tehran who had been selected through multistage cluster sampling method. This study is, due to its subject and purposes a descriptive study based on psychometric methods. The factor structure of the inventory was tested by AMOS software based on the fitting and modification indicators in the confirmatory factor analysis. The results showed that all items of the parenting style inventory except the items of 24, 8, 13, 18, assess the previously determined factors of the inventory, and that the inventory’s questions have a relatively good validity. Also, stratified alpha was used to calculate the reliability of the whole inventory, and Guttman coefficient was utilized to calculate the reliability of subscales. The outcomes indicated that the inventory and its subscales possess a relatively good reliability.

  11. Eating disorder examination: Factor structure and norms in a clinical female pediatric eating disorder sample.

    Science.gov (United States)

    O'Brien, Amy; Watson, Hunna J; Hoiles, Kimberley J; Egan, Sarah J; Anderson, Rebecca A; Hamilton, Matthew J; Shu, Chloe; McCormack, Julie

    2016-01-01

    The factor structure of the eating disorder examination (EDE) has never been tested in a clinical pediatric sample, and no normative data exist. The factor structure of an adapted EDE was examined in a clinical sample of 665 females aged 9-17 years with anorexia nervosa spectrum (70%), bulimia nervosa spectrum (12%), purging disorder (3%), and unspecified feeding and eating disorders (15%). The original four-factor model was a good fit in a confirmatory factor analysis as well a higher order model with three dimensions of restraint, eating concern, and combined weight concern/shape concern. Normative data are reported for clinicians to identify the percentiles in which their patients' score. The findings support dimensions of restraint, eating concern, weight concern, and shape concern in a clinical pediatric sample. This supports the factorial validity of the EDE, and the norms may assist clinicians to evaluate symptoms in females under 18 years. © 2015 Wiley Periodicals, Inc.

  12. Competition between intermolecular interaction and configuration entropy as the structure-determining factor for inclusion compounds

    Energy Technology Data Exchange (ETDEWEB)

    Subbotin, O.; Belosludov, V.; Adamova, T. [Russian Academy of Science, Novosibirsk (Russian Federation). Nikolaev Inst. of Inorganic Chemistry; Belosludov, R.; Kawazoe, Y. [Tohoku Univ., Aoba-ku, Sendai (Japan). Inst. for Materials Research; Kudoh, J.I. [Tohoku Univ., Aoba-ku, Sendai (Japan). Center for Northeast Asia Studies

    2008-07-01

    This paper presented a newly developed method to accurately predict the thermodynamic properties of clathrate hydrates, particularly their structural phase transitions under pressure. The method is based on the theory of Van-der-Waals and Platteeuw with some modifications that include the influence of guest molecules on the host lattice. The model was used to explain the exception from the established rule that small guest molecules form structure s1 and large molecules form structure s2 hydrates. In this study, the thermodynamic properties of argon (Ar) hydrate and methane hydrate, each in both cubic structure s1 and s2 were modelled. The model showed that two competing factors play a role in the formation of inclusions, notably the intermolecular interaction of guest molecules with water molecules, and the configuration entropy. Competition of these 2 factors determines the structure of hydrate formed at different pressures. The model provides an accurate description of the thermodynamic properties of gas hydrates and how they behave under pressure. For the argon hydrates, the structural phase transition from structure s2 to s1 at high pressure was predicted, while methane hydrates were predicted to be metastable in the s2 structure. The model can be used for other inclusion compounds with the same type of composition such as clathrate silicon, zeolites, and inclusion compounds of semiconductor elements. 17 refs., 5 figs.

  13. Dynamic structure factor for liquid He4 and quantum lattice model

    International Nuclear Information System (INIS)

    Lee, M.H.

    1975-01-01

    It has been realized for some time now that the quantum lattice model (or the anisotropic Heisenberg antiferromagnetic model) is a useful model for studying the properties of quantum liquids especially near the lambda transition. The static critical values calculated from the quantum lattice model are in good agreement with the observed values. Furthermore, it was shown recently that there are collective modes in the quantum lattice model which are equivalent to the plasmons. Hence, it would seem to be interesting to study the dynamic structure factor for the quantum lattice model and to make a comparison with experiment. Work on the dynamic structure factor is reported here. (Auth.)

  14. A temperature-dependent theory for HeII: Application to the liquid structure factor

    International Nuclear Information System (INIS)

    Chela-Flores, J.; Ghassib, H.B.

    1981-08-01

    A temperature-dependent theory is presented for HeII, which is based on both a gauge-theoretic formulation as well as a mean-field (Hartree) approach. A simple model calculation is then performed within this framework for the liquid structure factor of the system. In particular, explicit expressions are obtained for the low-momentum-transfer and low-temperature limits, which seem to conform with the available experimental data. Further, the curvature of the structure factor is predicted, under these circumstances, to be only mildly dependent on temperature. Throughout, we compare and contrast with other theoretical attempts, including Feynman's. (author)

  15. Determination of Partial Structure Factors of Molten Eutectic Ni33Ge67

    Science.gov (United States)

    Halm, Th.; Hoyer, W.; Neumann, H.; Bellissent, R.

    1993-03-01

    Using isotopic substitution and X-ray scattering, different weighted structure factors were measured and combined in order to calculate partial structure factors. Although we got an overdetermined system of equations, the solution of this problem was difficult due to the small value of the determinant. From the partial pair correlation functions and the radial concentration correlation function a splitting of the first coordination shell is obvious. The dip in SNi-Ge and the corresponding peak in SNi-Ni indicate some degree of charge transfer in the melt.

  16. Microscopic structure factor of liquid hydrogen by neutron-diffraction measurements

    International Nuclear Information System (INIS)

    Celli, M.; Bafile, U.; Zoppi, M.; Cuello, G.J.; Formisano, F.; Guarini, E.; Magli, R.; Neumann, M.

    2005-01-01

    The center-of-mass structure factor of liquid para hydrogen has been measured, using neutron diffraction, in four thermodynamic states close to the triple point. Path integral Monte Carlo simulations have been carried out at the same temperatures and densities. The present experimental data are in reasonable quantitative agreement with the simulations and closer to these results than previous neutron determinations available in the literature. The thermodynamic derivatives of the structure factor, from both experiment and simulation, have been compared to previous measurements obtaining a quantitative consistency

  17. Synchronous scattering and diffraction from gold nanotextured surfaces with structure factors

    Science.gov (United States)

    Gu, Min-Jhong; Lee, Ming-Tsang; Huang, Chien-Hsun; Wu, Chi-Chun; Chen, Yu-Bin

    2018-05-01

    Synchronous scattering and diffraction were demonstrated using reflectance from gold nanotextured surfaces at oblique (θi = 15° and 60°) incidence of wavelength λ = 405 nm. Two samples of unique auto-correlation functions were cost-effectively fabricated. Multiple structure factors of their profiles were confirmed with Fourier expansions. Bi-directional reflectance function (BRDF) from these samples provided experimental proofs. On the other hand, standard deviation of height and unique auto-correlation function of each sample were used to generate surfaces numerically. Comparing their BRDF with those of totally random rough surfaces further suggested that structure factors in profile could reduce specular reflection more than totally random roughness.

  18. The crystal structure of elongation factor G complexed with GDP, at 2.7 A resolution.

    OpenAIRE

    Czworkowski, J; Wang, J; Steitz, T A; Moore, P B

    1994-01-01

    Elongation factor G (EF-G) catalyzes the translocation step of protein synthesis in bacteria, and like the other bacterial elongation factor, EF-Tu--whose structure is already known--it is a member of the GTPase superfamily. We have determined the crystal structure of EF-G--GDP from Thermus thermophilus. It is an elongated molecule whose large, N-terminal domain resembles the G domain of EF-Tu, except for a 90 residue insert, which covers a surface that is involved in nucleotide exchange in E...

  19. Analysis on Impact Factors of Water Utilization Structure in Tianjin, China

    Directory of Open Access Journals (Sweden)

    Conglin Zhang

    2016-03-01

    Full Text Available Water is an essential foundation for socio-economic development and environmental protection. As such, it is very critical for a city’s sustainable development. This study analyzed the changes in water utilization structure and its impact factors using water consumption data for agricultural, industrial, domestic and ecological areas in the city of Tianjin, China from 2004 to 2013. On this base, the evolution law and impact factors of water utilization structure were depicted by information entropy and grey correlation respectively. These analyses lead to three main results. First, the total amount of water consumption in Tianjin increased slightly from 2004 to 2013. Second, the information entropy and equilibrium degree peaked in 2010. From 2004 to 2010, the water utilization structure tended to be more disordered and balanced. Third, the economic and social factors seemed to influence the water utilization structure, while the main impact factors were industrial structure, per capita green area, cultivated area, effective irrigation area, rural electricity consumption, animal husbandry output, resident population, per capita domestic water etc.

  20. The structure of a resuscitation-promoting factor domain from Mycobacterium tuberculosis shows homology to lysozymes

    OpenAIRE

    Cohen Gonsaud, M.; Barthe, P.; Bagneris, Claire; Henderson, B.; Ward, J.M.; Roumestand, C.; Keep, Nicholas H.

    2005-01-01

    Resuscitation-promoting factor (RPF) proteins reactivate stationary-phase cultures of (G+C)-rich Gram-positive bacteria including the causative agent of tuberculosis, Mycobacterium tuberculosis. We report the solution structure of the RPF domain from M. tuberculosis Rv1009 (RpfB) solved by heteronuclear multidimensional NMR. Structural homology with various glycoside hydrolases suggested that RpfB cleaved oligosaccharides. Biochemical studies indicate that a conserved active site glutamate is...

  1. NW-trending fault structures. A key factor to uranium mineralization in Egongshan volcanic basin

    International Nuclear Information System (INIS)

    Zhang Wanliang

    1996-01-01

    Influenced by the Tancheng-Lujiang fault system, the NW-trending fault structures in Egongshan basin are characterized by tensile-shearing, NE-dipping and dextrorotaty down slipping, having an obvious control over three uranium deposits and the overwhelming majority of uranium occurrences, and are the key factors to uranium mineralization. The study on the NW-trending fault structures is of practical significance in ore prospecting in Egongshan basin and other areas

  2. Evaluating response modification factor (R) for some types of steel structure

    OpenAIRE

    Doralba Valencia Restrepo; Gabriel F. Valencia Clement

    2008-01-01

    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...

  3. Factor structure of the Cannabis Experiences Questionnaire in a first-episode psychosis sample.

    Science.gov (United States)

    Birnbaum, Michael L; Cleary, Sean D; Ramsay Wan, Claire; Pauselli, Luca; Compton, Michael T

    2017-10-20

    The Cannabis Experiences Questionnaire (CEQ) was developed to measure the subjective experiences of cannabis use both during and after intoxication. Despite the need to better understand the nature of the complex and significant relationship between cannabis use and early psychosis, this questionnaire has rarely been used in individuals with first-episode psychosis. We conducted a set of factor analyses using CEQ data from 194 first-episode psychosis patients who used cannabis in order to uncover the underlying factor structure of the questionnaire and thus the overarching types of psychological experiences during/after using cannabis in young people with psychotic disorders. Our exploratory factor analysis identified 4 subscales, including: Distortions of Reality and Self-Perception (Factor 1), Euphoria Effects (Factor 2), Slowing and Amotivational Effects (Factor 3), and Anxiety and Paranoia Effects (Factor 4). Elucidating the underlying factor structure of the CEQ in first-episode psychosis samples could help researchers move towards a deeper understanding of the types of experiences associated with cannabis intoxication among young adults with first-episode psychosis and could inform the development of programs designed to reduce use, improve the course of illness, and possibly delay or prevent the onset of psychotic symptoms in those at risk. © 2017 John Wiley & Sons Australia, Ltd.

  4. Examining the Reliability, Validity and Factor Structure of the DRS-15 with College Athletes

    Directory of Open Access Journals (Sweden)

    Leilani Madrigal

    2016-07-01

    Full Text Available Hardiness, comprising feelings of commitment, control and challenge, is most frequently measured with the Dispositional Resiliency Scale (DRS, but little work has been done with the brief 15-item version.To examine the factor structure, reliability, validity, and item functioning for gender invariance of the 15-item DRS with 525 collegiate athletes from a wide range of sports. Convergent and divergent validity were examined through relationships with mental toughness, grit and competitive anxiety. Participants completed measures of mental toughness, optimism, grit, competitive anxiety, and the DRS-15.Confirmatory Factor Analysis revealed a poor fit for the three-factor hardiness model, and subsequent exploratory factor analysis yielded a four-factor model with better fit than the three-factor structure. Additionally, several items appear to be biased towards males or females. The fourth factor may be unique to the collegiate athlete population, and related to perceived lack of control in future life directions. Convergent and divergent validity were supported through correlations of DRS scores with related measures.The four-factor model should be tested with different samples to determine if these changes should be adapted when using the DRS-15 in collegiate athletics or other settings.

  5. Meta-Analysis of the Factor Structures of the Beck Depression Inventory-II.

    Science.gov (United States)

    Huang, Chiungjung; Chen, Jyun-Hong

    2015-08-01

    Two meta-analyses examined the factor structure of the Beck Depression Inventory-II (BDI-II). Study 1, which meta-analyzed 51 studies comprising 62 samples (N = 20,475) providing pattern matrices, determined that the two-factor solution comprising Cognitive and Somatic-Affective factors was supported for the full sample. The two-factor solution was also supported for subgroups of studies. As the factor structure varied somewhat between subgroups of studies, the strength of relationships between scale items and their underlying depressive symptoms varied. Hence, comparisons of mean BDI-II scores across subgroups can be misleading. Study 2 meta-analyzed 13 studies consisting of 16 samples (N = 5,128) providing covariance matrices among the 21 BDI-II items. The two-factor solution was again supported in Study 2. Nevertheless, the existence of a general depression factor was supported by the good fit of the one-factor model. © The Author(s) 2014.

  6. Wording effects and the factor structure of the 12-item General Health Questionnaire (GHQ-12)

    OpenAIRE

    Molina, Juan Gabriel

    2014-01-01

    The 12-item version of the General Health Questionnaire (GHQ-12) has become a popular screening instrument with which to measure general psychological health in different settings. Previous studies into the factorial structure of the GHQ-12 have mainly supported multifactor solutions, and only a few recent works have shown that the GHQ-12 was best represented by a single substantive factor when method effects associated with negatively worded items were considered. Confirmatory factor analysi...

  7. The structural variation of phytoplankton in the Gulf of Riga under the influence of environmental factors

    OpenAIRE

    Jurgensone, Iveta

    2011-01-01

    „The structural variation of phytoplankton in the Gulf of Riga under the influence of environmental factors.” Trends of phytoplankton (1976-2008) from the Gulf of Riga and the related environmental factors are investigated. Phytoplankton response to riverine DOM and nutrient increase was tested and the effect on the pelagic food web assessed. Changes in the winter-spring DIN/DIP ratio cause shift from diatoms to cyanobacteria. Dinoflagellate biomass remains constant after temperature excee...

  8. Internal consistency and factor structure of 12-item general health questionnaire in visually impaired students

    Science.gov (United States)

    Bakhla, Ajay Kumar; Verma, Vijay; Hembram, Mahesh; Praharaj, Samir Kumar; Sinha, Vinod Kumar

    2013-01-01

    Background: As there are no instruments to measure psychological wellness or distress in visually impaired students, we studied internal consistency and factor structure of GHQ-12 in visually impaired children. Materials and Methods: Internal consistency analysis (Cronbach's alpha and item total correlation) and exploratory factor analysis (principal component analysis) were carried out to identify factor structure of 12-item general health questionnaire (GHQ-12). Results: All items of GHQ-12 were significantly associated with each other and the Cronbach's alpha coefficient for the scale was 0.7. On analysis of principal component, three-factor solution was found that accounted for 47.92% of the total variance. The factors included, ‘general well-being’, ‘depression’ and ‘cognitive’, with Cronbach's alpha coefficients being 0.70, 0.59, and 0.34, respectively. Conclusion: Our study findings suggest GHQ-12 is a reliable with adequate internal consistency scale and multidimensional factor structure in visually impaired students. PMID:25013310

  9. Insights into structural and functional diversity of Dof (DNA binding with one finger) transcription factor.

    Science.gov (United States)

    Gupta, S; Malviya, N; Kushwaha, H; Nasim, J; Bisht, N C; Singh, V K; Yadav, D

    2015-03-01

    The structural, functional and in-silico studies of Dof transcription factor attempted so far reveals immense opportunity to analyze the plant genomes in terms of number of Dof genes and discuss in light of the evolution. The multiple functions of Dof genes needs to explored for crop improvement. Transcription factors play a very vital role in gene regulation at transcriptional level and are being extensively studied across phylas. In recent years, sequencing of plant genomes has led to genome-wide identification and characterizations of diverse types of plant-specific transcription factor gene family providing key insights into their structural and functional diversity. The DNA binding with one finger (Dof), a class belonging to C2H2-type zinc finger family proteins, is a plant-specific transcription factor having multiple roles such as seed maturation and germination, phytohormone and light-mediated regulation and plant responses to biotic and abiotic stresses. Dof proteins are present across plant lineage, from green algae to higher angiosperm, and represent a unique class of transcription factor having bifunctional binding activities, with both DNA and proteins, to regulate the complex transcriptional machinery in plant cells. The structural and functional diversity of the Dof transcription factor family along with the bioinformatics analysis highlighting the phylogeny of Dof families is reviewed in light of its importance in plant biotechnology for crop improvement.

  10. Internal consistency and factor structure of 12-item general health questionnaire in visually impaired students

    Directory of Open Access Journals (Sweden)

    Ajay Kumar Bakhla

    2013-01-01

    Full Text Available Background: As there are no instruments to measure psychological wellness or distress in visually impaired students, we studied internal consistency and factor structure of GHQ-12 in visually impaired children. Materials and Methods: Internal consistency analysis (Cronbach′s alpha and item total correlation and exploratory factor analysis (principal component analysis were carried out to identify factor structure of 12-item general health questionnaire (GHQ-12. Results: All items of GHQ-12 were significantly associated with each other and the Cronbach′s alpha coefficient for the scale was 0.7. On analysis of principal component, three-factor solution was found that accounted for 47.92% of the total variance. The factors included, ′general well-being′, ′depression′ and ′cognitive′, with Cronbach′s alpha coefficients being 0.70, 0.59, and 0.34, respectively. Conclusion: Our study findings suggest GHQ-12 is a reliable with adequate internal consistency scale and multidimensional factor structure in visually impaired students.

  11. ObStruct: A Method to Objectively Analyse Factors Driving Population Structure Using Bayesian Ancestry Profiles

    Science.gov (United States)

    Gayevskiy, Velimir; Klaere, Steffen; Knight, Sarah; Goddard, Matthew R.

    2014-01-01

    Bayesian inference methods are extensively used to detect the presence of population structure given genetic data. The primary output of software implementing these methods are ancestry profiles of sampled individuals. While these profiles robustly partition the data into subgroups, currently there is no objective method to determine whether the fixed factor of interest (e.g. geographic origin) correlates with inferred subgroups or not, and if so, which populations are driving this correlation. We present ObStruct, a novel tool to objectively analyse the nature of structure revealed in Bayesian ancestry profiles using established statistical methods. ObStruct evaluates the extent of structural similarity between sampled and inferred populations, tests the significance of population differentiation, provides information on the contribution of sampled and inferred populations to the observed structure and crucially determines whether the predetermined factor of interest correlates with inferred population structure. Analyses of simulated and experimental data highlight ObStruct's ability to objectively assess the nature of structure in populations. We show the method is capable of capturing an increase in the level of structure with increasing time since divergence between simulated populations. Further, we applied the method to a highly structured dataset of 1,484 humans from seven continents and a less structured dataset of 179 Saccharomyces cerevisiae from three regions in New Zealand. Our results show that ObStruct provides an objective metric to classify the degree, drivers and significance of inferred structure, as well as providing novel insights into the relationships between sampled populations, and adds a final step to the pipeline for population structure analyses. PMID:24416362

  12. ObStruct: a method to objectively analyse factors driving population structure using Bayesian ancestry profiles.

    Directory of Open Access Journals (Sweden)

    Velimir Gayevskiy

    Full Text Available Bayesian inference methods are extensively used to detect the presence of population structure given genetic data. The primary output of software implementing these methods are ancestry profiles of sampled individuals. While these profiles robustly partition the data into subgroups, currently there is no objective method to determine whether the fixed factor of interest (e.g. geographic origin correlates with inferred subgroups or not, and if so, which populations are driving this correlation. We present ObStruct, a novel tool to objectively analyse the nature of structure revealed in Bayesian ancestry profiles using established statistical methods. ObStruct evaluates the extent of structural similarity between sampled and inferred populations, tests the significance of population differentiation, provides information on the contribution of sampled and inferred populations to the observed structure and crucially determines whether the predetermined factor of interest correlates with inferred population structure. Analyses of simulated and experimental data highlight ObStruct's ability to objectively assess the nature of structure in populations. We show the method is capable of capturing an increase in the level of structure with increasing time since divergence between simulated populations. Further, we applied the method to a highly structured dataset of 1,484 humans from seven continents and a less structured dataset of 179 Saccharomyces cerevisiae from three regions in New Zealand. Our results show that ObStruct provides an objective metric to classify the degree, drivers and significance of inferred structure, as well as providing novel insights into the relationships between sampled populations, and adds a final step to the pipeline for population structure analyses.

  13. Granulocyte colony-stimulating factor increases CD4+ T cell counts of human immunodeficiency virus-infected patients receiving stable, highly active antiretroviral therapy

    DEFF Research Database (Denmark)

    Aladdin, H; Ullum, H; Dam Nielsen, S.

    2000-01-01

    Thirty human immunodeficiency virus (HIV)-infected patients with CD4+ T cell counts active antiretroviral therapy (HAART) for at least 24 weeks were randomized to receive either placebo or granulocyte colony-stimulating factor (G-CSF; 0.3 mg/mL 3 times...... counts resulted from increases in CD45RO+ memory T cells and cells expressing the CD38 activation marker. Lymphocyte proliferative responses to phytohemagglutinin and Candida antigen decreased, whereas NK cell activity and plasma HIV RNA did not change during G-CSF treatment. After 24 weeks, all immune...... a week) for 12 weeks. Blood samples were collected at specified time points. G-CSF treatment enhanced the total lymphocyte count (P=.002) and increased CD3+ (P=.005), CD4+ (P=.03), and CD8+ (P=.004) T cell counts as well as numbers of CD3-CD16+CD56+ NK cells (P=.001). The increases in CD4+ and CD8+ cell...

  14. Normal modified stable processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2002-01-01

    This paper discusses two classes of distributions, and stochastic processes derived from them: modified stable (MS) laws and normal modified stable (NMS) laws. This extends corresponding results for the generalised inverse Gaussian (GIG) and generalised hyperbolic (GH) or normal generalised inverse...... Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process...

  15. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Letolle, R.; Mariotti, A.; Bariac, T.

    1991-06-01

    This report reviews the historical background and the properties of stable isotopes, the methods used for their measurement (mass spectrometry and others), the present technics for isotope enrichment and separation, and at last the various present and foreseeable application (in nuclear energy, physical and chemical research, materials industry and research; tracing in industrial, medical and agronomical tests; the use of natural isotope variations for environmental studies, agronomy, natural resources appraising: water, minerals, energy). Some new possibilities in the use of stable isotope are offered. A last chapter gives the present state and forecast development of stable isotope uses in France and Europe

  16. Trophic structure in a pilot system for the integrated multi-trophic aquaculture off the east coast of Korean peninsula as determined by stable isotopes

    International Nuclear Information System (INIS)

    Park, Hyun Je; Han, Eunah; Lee, Won Chan; Kwak, Jung Hyun; Kim, Hyung Chul; Park, Mi Seon; Kang, Chang-Keun

    2015-01-01

    Highlights: • A pilot system for the integrated multi-trophic aquaculture was installed. • The black rockfish, sea cucumber, oyster, and macroalgae were co-cultured. • Co-cultured sea cucumber at the IMTA site assimilated aquaculture wastes. • Fish cage-waste contribution to food web in/around the IMTA system was minor. • The sea cucumber was identified as an extractive species of fish cage wastes. - Abstract: To assess the potential for nutritional exploitation of caged-fish-derived waste through the use of extractive co-cultured species in a pilot system for an integrated multi-trophic aquaculture (IMTA), we compared their C and N stable isotope ratios with those of uncultured macroinvertebrates in and around the system. Black rockfish were co-cultured with sea cucumber, oyster, and two macroalgae as extractive species. Isotope signatures of the co-cultured sea cucumber at the IMTA site differed from those at the control site, indicating their assimilation of aquaculture wastes. In contrast, δ 13 C and δ 15 N of individual taxa of the cultured oyster and uncultured invertebrates were consistent between sites, suggesting a minor contribution of the aquaculture waste to benthic and pelagic food chains in and around the IMTA system. These results provide evidence of the suitability of using sea cucumber as an extractive species to reduce the impact of a monoculture system on the ambient environment

  17. Trophic structure in a pilot system for the integrated multi-trophic aquaculture off the east coast of Korean peninsula as determined by stable isotopes.

    Science.gov (United States)

    Park, Hyun Je; Han, Eunah; Lee, Won Chan; Kwak, Jung Hyun; Kim, Hyung Chul; Park, Mi Seon; Kang, Chang-Keun

    2015-06-15

    To assess the potential for nutritional exploitation of caged-fish-derived waste through the use of extractive co-cultured species in a pilot system for an integrated multi-trophic aquaculture (IMTA), we compared their C and N stable isotope ratios with those of uncultured macroinvertebrates in and around the system. Black rockfish were co-cultured with sea cucumber, oyster, and two macroalgae as extractive species. Isotope signatures of the co-cultured sea cucumber at the IMTA site differed from those at the control site, indicating their assimilation of aquaculture wastes. In contrast, δ(13)C and δ(15)N of individual taxa of the cultured oyster and uncultured invertebrates were consistent between sites, suggesting a minor contribution of the aquaculture waste to benthic and pelagic food chains in and around the IMTA system. These results provide evidence of the suitability of using sea cucumber as an extractive species to reduce the impact of a monoculture system on the ambient environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Hierarchical MoS2 tubular structures internally wired by carbon nanotubes as a highly stable anode material for lithium-ion batteries.

    Science.gov (United States)

    Chen, Yu Ming; Yu, Xin Yao; Li, Zhen; Paik, Ungyu; Lou, Xiong Wen David

    2016-07-01

    Molybdenum disulfide (MoS2), a typical two-dimensional material, is a promising anode material for lithium-ion batteries because it has three times the theoretical capacity of graphite. The main challenges associated with MoS2 anodes are the structural degradation and the low rate capability caused by the low intrinsic electric conductivity and large strain upon cycling. Here, we design hierarchical MoS2 tubular structures internally wired by carbon nanotubes (CNTs) to tackle these problems. These porous MoS2 tubular structures are constructed from building blocks of ultrathin nanosheets, which are believed to benefit the electrochemical reactions. Benefiting from the unique structural and compositional characteristics, these CNT-wired MoS2 tubular structures deliver a very high specific capacity of ~1320 mAh g(-1) at a current density of 0.1 A g(-1), exceptional rate capability, and an ultralong cycle life of up to 1000 cycles. This work may inspire new ideas for constructing high-performance electrodes for electrochemical energy storage.

  19. Serviceability design load factors and reliability assessments for reinforced concrete containment structures

    International Nuclear Information System (INIS)

    Han Bong Koo

    1998-01-01

    A reinforced concrete nuclear power plant containment structure is subjected to various random static and stochastic loads during its lifetime. Since these loads involve inherent randomness and other uncertainties, an appropriate probabilistic model for each load must be established in order to perform reliability analysis. The current ASME code for reinforced concrete containment structures are not based on probability concepts. The stochastic nature of natural hazard or accidental loads and the variations of material properties require a probabilistic approach for a rational assessment of structural safety and performance. The paper develops probability-based load factors for the limit state design of reinforced concrete containment structures. The purpose of constructing reinforced concrete containment structure is to protect against radioactive release, and so the use of a serviceability limit state against crack failure that can cause the emission of radioactive materials is suggested as a critical limit state for reinforced concrete containment structures. Load factors for the design of reinforced concrete containment structures are proposed and carried out the reliability assessments. (orig.)

  20. Modelling the elastic scattering in diagnostic radiology: the importance of structure form factors

    Science.gov (United States)

    Cardoso, S. C.; Gonçalves, O. D.; Schechter, H.; Eichler, J.

    2003-07-01

    The importance of structure form factors in describing elastic scattering in diagnostic radiology was studied through a Monte Carlo code built to reproduce scattering in large water samples. The code, developed by us, considers all relevant interactions, including multiple scattering and interference due to scattering by the liquid structure. Geometrical conditions and energies similar to those found in radiology were used. The secondary to primary radiation ratio using the usual free atom approximation and the structure form factor was obtained and both approaches were compared. Calculations of radiological parameters such as the angular distribution of photons incident on the detector and the fraction of scattered photons stopped by anti-scattering grids were also performed considering mammography, thorax and abdomen radiography conditions. The results have shown that S(beta)/P depends on the experimental set-up, being more important for low momentum transfers and sample sizes for which the multiple scattering is not expected to be significant, as in the case of mammography. It was also verified that large samples increase the probability of multiple scattering, masking the structure peak in S(beta) and making the sample structure important just for relatively thin samples. Considering mammography-like geometry, the maximum of the S(beta)/P distribution considering structure form factors occurs around 15° while the correspondent maximum without considering the structure factors occurs around 10° for any sample thickness. S(beta)/P is almost independent of the irradiation field, with the maximum remaining at 15° and 10° for the SFF and FAFF, respectively. The cases studied in this paper stress some conditions in which it is mandatory to use SFF, but since it requires no further significant efforts, the SFF approach is recommended as a standard procedure when describing the elastic scattering process in radiology.

  1. Factor Structure of the Iranian Version of 12-Item General Health Questionnaire

    Science.gov (United States)

    Rahmati Najarkolaei, Fatemeh; Raiisi, Fatemeh; Rahnama, Parvin; Gholami Fesharaki, Mohammad; Zamani, Omid; Jafari, Mohammad Reza; Montazeri, Ali

    2014-01-01

    Background: The 12-Item General Health (GHQ-12) questionnaire is one of the most commonly used instruments in screening studies on mental health. Objectives: The current study aimed to examine the factor structure of the GHQ-12 questionnaire among the students in Iran. Materials and Methods: It was a cross-sectional study in which 428 university students were recruited and completed the GHQ-12. Reliability of the GHQ-12 was evaluated using the Cronbach's alpha and the split-half method by applying the Spearman-Brown coefficient. Factor structure of the questionnaire was extracted by exploratory factor analysis (EFA). Confirmatory factor analysis (CFA) was conducted to assess how well the EFA extracted model fitted the observed data. Results: The mean age of the participants was 22.83 years (SD = 3.09). Most of them were female (56.1%) and 81% were unemployed. The Cronbach’s alpha coefficient for the Iranian version of GHQ-12 was 0.85. Using the split-half method, the alpha for the social dysfunction was found to be 0.77; it was 0.76 for the psychological distress. The principal component analysis revealed a two-factor structure for the questionnaire including social dysfunction and psychological distress that explained 48% of the observed variances. The confirmatory factor analysis was showed fit for the data. Conclusions: The current study findings confirm that the Iranian version of GHQ-12 has a good factor structure and is a reliable and valid instrument to measure psychological distress and social dysfunction. PMID:25593708

  2. Exploration of the factor structure of the Kirton Adaption-Innovation Inventory using bootstrapping estimation.

    Science.gov (United States)

    Im, Subin; Min, Soonhong

    2013-04-01

    Exploratory factor analyses of the Kirton Adaption-Innovation Inventory (KAI), which serves to measure individual cognitive styles, generally indicate three factors: sufficiency of originality, efficiency, and rule/group conformity. In contrast, a 2005 study by Im and Hu using confirmatory factor analysis supported a four-factor structure, dividing the sufficiency of originality dimension into two subdimensions, idea generation and preference for change. This study extends Im and Hu's (2005) study of a derived version of the KAI by providing additional evidence of the four-factor structure. Specifically, the authors test the robustness of the parameter estimates to the violation of normality assumptions in the sample using bootstrap methods. A bias-corrected confidence interval bootstrapping procedure conducted among a sample of 356 participants--members of the Arkansas Household Research Panel, with middle SES and average age of 55.6 yr. (SD = 13.9)--showed that the four-factor model with two subdimensions of sufficiency of originality fits the data significantly better than the three-factor model in non-normality conditions.

  3. Efficient expression of stable recombinant human insulin-like growth factor-1 fusion with human serum albumin in Chinese hamster ovary cells.

    Science.gov (United States)

    Wan, Aini; Xu, Dongsheng; Liu, Kedong; Peng, Lin; Cai, Yanfei; Chen, Yun; He, Yang; Yang, Jianfeng; Jin, Jian; Li, Huazhong

    2017-08-09

    Insulin-like growth factor-1 (IGF-1) plays a crucial role in cell development, differentiation, and metabolism, and has been a potential therapeutic agent for many diseases. Chinese hamster ovary (CHO) cells are widely used for production of recombinant therapeutic proteins, but the expression level of IGF-1 in CHO cells is very low (1,500 µg/L) and the half-life of IGF-1 in blood circulation is only 4.5 min according to previous studies. Therefore, IGF-1 was fused to long-circulating serum protein human serum albumin (HSA) and expressed in CHO cells. After 8-day fed-batch culture, the expression level of HSA-IGF-1 reached 100 mg/L. The fusion protein HSA-IGF-1 was purified with a recovery of 35% using a two-step chromatographic procedure. According to bioactivity assay, the purified HSA-IGF-1 could stimulate the proliferation of NIH3T3 cells in a dose-dependent fashion and promote the cell-cycle progression. Besides this, HSA-IGF-1 could bind to IGF-1 receptor on cell membrane and activate the intracellular PI3K/AKT signaling pathway. Our study suggested that HSA fusion technology carried out in CHO cells not only provided bioactivity in HSA-IGF-1 for further research but also offered a beneficial strategy to produce other similar cytokines in CHO cells.

  4. Factor structure of DSM-5 PTSD symptoms in trauma-exposed adolescents: Examining stability across time.

    Science.gov (United States)

    Wang, Li; Cao, Xing; Cao, Chengqi; Fang, Ruojiao; Yang, Haibo; Elhai, Jon D

    2017-12-01

    This study investigated the latent structure of DSM-5 PTSD symptoms using two-wave longitudinal data collected from a sample of adolescents exposed to an explosion accident. Two waves of surveys were conducted approximately 3 and 8 months after the accident, respectively. A total of 836 students completed the baseline survey, and 762 students completed the follow-up survey. The results of confirmatory factor analyses(CFA) indicated that a seven-factor hybrid model composed of intrusion, avoidance, negative affect, anhedonia, externalizing behaviors, anxious arousal and dysphoric arousal factors yielded significantly better data fit at both waves than the other models including the DSM-5 four-factor model, the six-factor anhedonia and externalizing behaviors models. Furthermore, the results of CFA invariance tests supported the longitudinal invariance of the model. Implications and limitations in terms of these results are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Analysing Stable Time Series

    National Research Council Canada - National Science Library

    Adler, Robert

    1997-01-01

    We describe how to take a stable, ARMA, time series through the various stages of model identification, parameter estimation, and diagnostic checking, and accompany the discussion with a goodly number...

  6. Longitudinal Factor Structure of General Self-Concept and Locus of Control among High School Students

    Science.gov (United States)

    Wang, Ze; Su, Ihui

    2013-01-01

    This study examined the longitudinal factor structure of general self-concept and locus of control among high school students over a 4-year period, with data from the National Educational Longitudinal Study of 1988. Measurement invariance was tested over time and across gender and ethnic groups; second-order piecewise latent growth models were…

  7. DREB1/CBF transcription factors: their structure, function and role in ...

    Indian Academy of Sciences (India)

    This review is mainly focussed on the structural characteristics as well as transcriptional regulation of gene expression in response to various abiotic stresses, with particular ... The recent progress related to genetic engineering of DREB1/CBF transcription factors in various crops and model plants is also summarized.

  8. Incorporation of crystallographic temperature factors in the statistical analysis of protein tertiary structures.

    Science.gov (United States)

    Bott, R; Frane, J

    1990-08-01

    A method to identify statistically significant differences between equivalent atoms in two closely related protein X-ray crystallographic structures is described. This method uses the linear relationship found between the logarithm of the distance between equivalent atoms and their mean temperature factor to determine, by linear regression, the expected difference and variance.

  9. Factor Structure of Attention Deficit Hyperactivity Disorder Symptoms for Children Age 3 to 5 Years

    Science.gov (United States)

    McGoey, Kara E.; Schreiber, James; Venesky, Lindsey; Westwood, Wendy; McGuirk, Lindsay; Schaffner, Kristen

    2015-01-01

    The diagnosis of attention deficit hyperactivity disorder (ADHD) distinguishes two dimensions of symptoms, inattention and hyperactivity-impulsivity for ages 3 to adulthood. Currently, no separate classification for preschool-age children exists, whereas preliminary research suggests that the two-factor structure of ADHD may not match the…

  10. Intrinsic factors of Peltigera lichens influence the structure of the associated soil bacterial microbiota.

    Science.gov (United States)

    Leiva, Diego; Clavero-León, Claudia; Carú, Margarita; Orlando, Julieta

    2016-11-01

    Definition of lichens has evolved from bi(tri)partite associations to multi-species symbioses, where bacteria would play essential roles. Besides, although soil bacterial communities are known to be affected by edaphic factors, when lichens grow upon them these could become less preponderant. We hypothesized that the structure of both the lichen microbiota and the microbiota in the soil underneath lichens is shaped by lichen intrinsic and extrinsic factors. In this work, intrinsic factors corresponded to mycobiont and cyanobiont identities of Peltigera lichens, metabolite diversity and phenoloxidase activity and extrinsic factors involved the site of the forest where lichens grow. Likewise, the genetic and metabolic structure of the lichen and soil bacterial communities were analyzed by fingerprinting. Among the results, metabolite diversity was inversely related to the genetic structure of bacterial communities of lichens and soils, highlighting the far-reaching effect of these substances; while phenoloxidase activity was inversely related to the metabolic structure only of the lichen bacterial microbiota, presuming a more limited effect of the products of these enzymes. Soil bacterial microbiota was different depending on the site and, strikingly, according to the cyanobiont present in the lichen over them, which could indicate an influence of the photobiont metabolism on the availability of soil nutrients. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Factor Structure of the Restricted Academic Situation Scale: Implications for ADHD

    Science.gov (United States)

    Karama, Sherif; Amor, Leila Ben; Grizenko, Natalie; Ciampi, Antonio; Mbekou, Valentin; Ter-Stepanian, Marina; Lageix, Philippe; Baron, Chantal; Schwartz, George; Joober, Ridha

    2009-01-01

    Background: To study the factor structure of the Restricted Academic Situation Scale (RASS), a psychometric tool used to assess behavior in children with ADHD, 117 boys and 21 girls meeting "Diagnostic and Statistical Manual of Mental Disorders" (4th ed.; "DSM-IV") criteria for ADHD and aged between 6 and 12 years were recruited. Assessments were…

  12. Educational achievement, personality, and behavior: assessment, factor structure and implications for theory and practice.

    Science.gov (United States)

    Gaffney, Tim W; Perryman, Cassandra

    2012-01-01

    The purposes of this research were to first examine the evidence regarding the factor structure of educational achievement tests in the context of two theoretical models of cognitive ability (psychometric g and mutualism) that have been proposed to explain this structure as well as the underlying processes that may be responsible for its emergence in dimensionality studies. Then, the factor structure underlying a sample of the standardized educational achievement tests used by California in its statewide school accountability program was compared to those emerging from a selection of behavioral and personality assessments. As expected, the educational achievement tests exhibited a strong and uniformly positive manifold resulting in greater unidimensionality as evidenced by a dominant general factor in bi-factor analysis then either the personality or behavioral assessments. The implications of these structural differences are discussed with respect to the two theoretical perspective as well as in the context of formative and summative educational inferences in particular, and the school accountability and reform movement in general.

  13. Wording effects and the factor structure of the 12-item General Health Questionnaire (GHQ-12).

    Science.gov (United States)

    Molina, J Gabriel; Rodrigo, Maria F; Losilla, Josep-Maria; Vives, Jaume

    2014-09-01

    The 12-item version of the General Health Questionnaire (GHQ-12) has become a popular screening instrument with which to measure general psychological health in different settings. Previous studies into the factorial structure of the GHQ-12 have mainly supported multifactor solutions, and only a few recent works have shown that the GHQ-12 was best represented by a single substantive factor when method effects associated with negatively worded items were considered. Confirmatory factor analysis was applied to compare competing measurement models from previous research, including correlated traits-correlated methods and correlated traits-correlated uniquenesses approaches, to obtain further evidence about the factorial structure of the GHQ-12. This goal was achieved with data from 3,050 participants who completed the GHQ-12 included in the Catalonian Survey of Working Conditions (Catalonian Labor Relations and Quality of Work Department, 2012). The results showed additional evidence that the GHQ-12 has a unidimensional structure after controlling for method effects associated with negatively worded items. Furthermore, we found evidence for our hypothesis about the spurious nature of the 3-factor solution in Graetz's (1991) model after comparing its fit with that found for alternative models resulting from different combinations of the negatively worded items. An implication of our results is that future research about the factor structure of the GHQ-12 should take method effects associated with negative wording into account in order to avoid reaching inaccurate conclusions about its dimensionality. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  14. The Hierarchical Factor Structure Of The Wechsler Preschool And Primary Scale Of Intelligence

    Science.gov (United States)

    Wallbrown, Fred H.; And Others

    1973-01-01

    A Wherry-Wherry hierarchical factor analysis was performed on the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) subtest intercorrelations for each of six age groups. A hierarchical arrangement of abilities highly congruent with Vernon's structure of intellect theory was obtained. The findings support the construct validity of the…

  15. Factor Structure of the PAS-ADD Checklist with Adults with Intellectual Disabilities

    Science.gov (United States)

    Hatton, Chris; Taylor, John J.

    2008-01-01

    Background: The PAS-ADD Checklist is designed to screen for likely mental health problems in people with intellectual disabilities (ID). The specificity of recommended subscales derived from diagnostic criteria is unclear. This paper therefore investigates the factor structure of the PAS-ADD Checklist to determine the adequacy of empirically…

  16. Delaware School Climate Survey--Student: Its Factor Structure, Concurrent Validity, and Reliability

    Science.gov (United States)

    Bear, George G.; Gaskins, Clare; Blank, Jessica; Chen, Fang Fang

    2011-01-01

    The Delaware School Climate Survey-Student (DSCS-S) was developed to provide schools with a brief and psychometrically sound student survey for assessing school climate, particularly the dimensions of social support and structure. Confirmatory factor analyses, conducted on a sample of 11,780 students in 85 schools, showed that a bifactor model…

  17. The Higher Order Factor Structure and Gender Invariance of the Pathological Narcissism Inventory

    Science.gov (United States)

    Wright, Aidan G. C.; Lukowitsky, Mark R.; Pincus, Aaron L.; Conroy, David E.

    2010-01-01

    The Pathological Narcissism Inventory (PNI) is a recently developed multidimensional inventory for the assessment of pathological narcissism. The authors describe and report the results of two studies that investigate the higher order factor structure and gender invariance of the PNI. The results of the first study indicate that the PNI has a…

  18. Charge-charge liquid structure factor and the freezing of alkali halides

    International Nuclear Information System (INIS)

    March, N.H.; Tosi, M.P.

    1980-10-01

    The peak height of the charge-charge liquid structure factor Ssub(QQ) in molten alkali halides is proposed as a criterion for freezing. Available data on molten alkali chlorides, when extrapolated to the freezing point suggests Ssub(QQ)sup(max) approximately 5. (author)

  19. Factor structure of the autonomy preference index in people with severe mental illness.

    Science.gov (United States)

    Bonfils, Kelsey A; Adams, Erin L; Mueser, Kim T; Wright-Berryman, Jennifer L; Salyers, Michelle P

    2015-08-30

    People vary in the amount of control they want to exercise over decisions about their healthcare. Given the importance of patient-centered care, accurate measurement of these autonomy preferences is critical. This study aimed to assess the factor structure of the Autonomy Preference Index (API), used widely in general healthcare, in individuals with severe mental illness. Data came from two studies of people with severe mental illness (N=293) who were receiving mental health and/or primary care/integrated care services. Autonomy preferences were assessed with the API regarding both psychiatric and primary care services. Confirmatory factor analysis was used to evaluate fit of the hypothesized two-factor structure of the API (decision-making autonomy and information-seeking autonomy). Results indicated the hypothesized structure for the API did not adequately fit the data for either psychiatric or primary care services. Three problematic items were dropped, resulting in adequate fit for both types of treatment. These results suggest that with relatively minor modifications the API has an acceptable factor structure when asking people with severe mental illness about their preferences to be involved in decision-making. The modified API has clinical and research utility for this population in the burgeoning field of autonomy in patient-centered healthcare. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Reliability Analysis of a Composite Blade Structure Using the Model Correction Factor Method

    DEFF Research Database (Denmark)

    Dimitrov, Nikolay Krasimiroy; Friis-Hansen, Peter; Berggreen, Christian

    2010-01-01

    This paper presents a reliability analysis of a composite blade profile. The so-called Model Correction Factor technique is applied as an effective alternate approach to the response surface technique. The structural reliability is determined by use of a simplified idealised analytical model which...

  1. INTENSITY STATISTICS AND NORMALIZED STRUCTURE FACTORS FOR CRYSTALS WITH AN INCOMMENSURATE ONE-DIMENSIONAL MODULATION

    NARCIS (Netherlands)

    LAM, EJW; BEURSKENS, PT; VANSMAALEN, S

    1993-01-01

    An analytical expression is derived for the probability density function (p.d.f.) of X-ray structure-factor amplitudes of a crystal with an incommensurate one-dimensional modulation. The influence of the (3+1)-dimensional superspace symmetry is taken into account. It is shown that, in first-order

  2. The Relationship of Bureaucratic Structure to School Climate: An Exploratory Factor Analysis of Construct Validity

    Science.gov (United States)

    Lennon, Patricia A.

    2010-01-01

    This researcher examined the relationship of bureaucratic structure to school climate by means of an exploratory factor analysis of a measure of bureaucracy developed by Hoy and Sweetland (2000) and the four dimensional measure of climate developed by Hoy, Smith, and Sweetland (2002). Since there had been no other empirical studies whose authors…

  3. International cross-border migration in the South-East Baltic: factors, structure, consequences

    Directory of Open Access Journals (Sweden)

    Yemelyanova Larisa

    2010-12-01

    Full Text Available This article presents the results of an integrated research encompassing both the study of migration processes in the South-East Baltic (volume, structure, directions and the analysis of factors affecting migration mobility of the population as well as the assessment of migration influence on the socioeconomic development of three border territories.

  4. Structural Biology of Tumor Necrosis Factor Demonstrated for Undergraduates Instruction by Computer Simulation

    Science.gov (United States)

    Roy, Urmi

    2016-01-01

    This work presents a three-dimensional (3D) modeling exercise for undergraduate students in chemistry and health sciences disciplines, focusing on a protein-group linked to immune system regulation. Specifically, the exercise involves molecular modeling and structural analysis of tumor necrosis factor (TNF) proteins, both wild type and mutant. The…

  5. The Performance of Multi-Factor Term Structure Models for Pricing and Hedging Caps and Swaptions

    NARCIS (Netherlands)

    Driessen, J.J.A.G.; Klaassen, P.; Melenberg, B.

    2000-01-01

    In this paper we empirically compare different term structure models when it comes to the pricing and hedging of caps and swaptions.We analyze the influence of the number of factors on the pricing and hedging results, and investigate which type of data -interest rate data or derivative price data-

  6. Factor Structure of the "Escala de Autoeficacia para la Depresion en Adolescentes" (EADA)

    Science.gov (United States)

    Diaz-Santos, Mirella; Cumba-Aviles, Eduardo; Bernal, Guillermo; Rivera-Medina, Carmen

    2011-01-01

    The current concept and measures of self-efficacy for depression in adolescents do not consider developmental and cultural aspects essential to understand and assess this construct in Latino youth. We examined the factor structure of the "Escala de Autoeficacia para la Depresion en Adolescentes" (EADA), a Spanish instrument designed to…

  7. The Factor Structure of Preschool Learning Behaviors Scale Scores in Peruvian Children

    Science.gov (United States)

    Hahn, Kathryn R.; Schaefer, Barbara A.; Merino, Cesar; Worrell, Frank C.

    2009-01-01

    The factor structure of the Escala de Conductas de Aprendizaje Preescolar (ECAP), a Spanish translation of the Preschool Learning Behaviors Scale (PLBS), was examined in this study. Children aged 2 to 6 years (N = 328) enrolled in public and private preschools in the Republic of Peru were rated by classroom teachers on the frequency of observable,…

  8. Posttraumatic Stress Disorder's Frequency and Intensity Ratings Are Associated with Factor Structure Differences in Military Veterans

    Science.gov (United States)

    Elhai, Jon D.; Palmieri, Patrick A.; Biehn, Tracey L.; Frueh, B. Christopher; Magruder, Kathryn M.

    2010-01-01

    We examined possible differences in the factor structure of posttraumatic stress disorder (PTSD) on the basis of whether frequency or intensity symptom response formats were used to assess PTSD. Participants included 669 veterans recruited from an epidemiological study of four Veterans Affairs Medical Centers' primary care clinics in the…

  9. Factors correlating with significant differences between X-ray structures of myoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Rashin, Alexander A., E-mail: alexander-rashin@hotmail.com [BioChemComp Inc., 543 Sagamore Avenue, Teaneck, NJ 07666 (United States); Iowa State University, 112 Office and Lab Bldg, Ames, IA 50011-3020 (United States); Domagalski, Marcin J. [University of Virginia, 1340 Jefferson Park Avenue, Jordan Hall, Room 4223, Charlottesville, VA 22908 (United States); Zimmermann, Michael T. [Iowa State University, 112 Office and Lab Bldg, Ames, IA 50011-3020 (United States); Minor, Wladek [University of Virginia, 1340 Jefferson Park Avenue, Jordan Hall, Room 4223, Charlottesville, VA 22908 (United States); Chruszcz, Maksymilian [University of Virginia, 1340 Jefferson Park Avenue, Jordan Hall, Room 4223, Charlottesville, VA 22908 (United States); University of South Carolina, 631 Sumter Street, Columbia, SC 29208 (United States); Jernigan, Robert L. [Iowa State University, 112 Office and Lab Bldg, Ames, IA 50011-3020 (United States); BioChemComp Inc., 543 Sagamore Avenue, Teaneck, NJ 07666 (United States)

    2014-02-01

    Conformational differences between myoglobin structures are studied. Most structural differences in whale myoglobin beyond the uncertainty threshold can be correlated with a few specific structural factors. There are always exceptions and a search for additional factors is needed. The results might have serious implications for biological insights from conformational differences. Validation of general ideas about the origins of conformational differences in proteins is critical in order to arrive at meaningful functional insights. Here, principal component analysis (PCA) and distance difference matrices are used to validate some such ideas about the conformational differences between 291 myoglobin structures from sperm whale, horse and pig. Almost all of the horse and pig structures form compact PCA clusters with only minor coordinate differences and outliers that are easily explained. The 222 whale structures form a few dense clusters with multiple outliers. A few whale outliers with a prominent distortion of the GH loop are very similar to the cluster of horse structures, which all have a similar GH-loop distortion apparently owing to intermolecular crystal lattice hydrogen bonds to the GH loop from residues near the distal histidine His64. The variations of the GH-loop coordinates in the whale structures are likely to be owing to the observed alternative intermolecular crystal lattice bond, with the change to the GH loop distorting bonds correlated with the binding of specific ‘unusual’ ligands. Such an alternative intermolecular bond is not observed in horse myoglobins, obliterating any correlation with the ligands. Intermolecular bonds do not usually cause significant coordinate differences and cannot be validated as their universal cause. Most of the native-like whale myoglobin structure outliers can be correlated with a few specific factors. However, these factors do not always lead to coordinate differences beyond the previously determined uncertainty

  10. Reliability and Concurrent Validation of the IPIP Big-Five Factor Markers in China: Consistencies in Factor Structure between Internet-Obtained Heterosexual and Homosexual Samples.

    Science.gov (United States)

    Zheng, Lijun; Goldberg, Lewis R; Zheng, Yong; Zhao, Yufang; Tang, Yonglong; Liu, Li

    2008-11-01

    Previous studies have suggested the cross-cultural generalizability of a 5-factor structure for personality traits. In this article, we analyzed the utility of 2 versions (100-item and 50-item) of the IPIP Big-Five factor markers in both heterosexual (N = 633) and homosexual (N = 437) samples in China. Factor analysis within versions showed that both versions of these IPIP measures showed clear 5-factor orthogonal structures that were nearly identical to the American structure in both subject samples. The reliabilities of the five factors were quite high except for the 50-item measure of Agreeableness. The part-whole correlations between the 100-item and 50-item factors were high, as were the factor congruence coefficients between the heterosexual and the homosexual samples. Both versions of the IPIP Big-Five factor markers were strongly correlated with the scales from the Big Five Inventory (BFI: John, Donahue & Kentle, 1991), thus providing some concurrent validation in a Chinese context.

  11. Factor structure of the Emotions as a Child Scale in late adolescence and emerging adulthood.

    Science.gov (United States)

    Guo, Jinhong; Mrug, Sylvie; Knight, David C

    2017-09-01

    Although the Emotions as a Child Scale (EAC) has been widely used in research with children and adolescents, no peer-reviewed studies have examined its factor structure using factor analytic methods. Likewise, the measurement equivalence of the scale across gender and race/ethnicity has never been investigated. To address these gaps, this study examines the factor structure of the scale in late adolescence and emerging adulthood, compares it to previous theory-driven models, and evaluates its measurement invariance across gender and 2 racial/ethnic groups. Participants were 1,087 individuals participating in a larger community-based study of adolescent health (M = 19.35 years, SD = 1.19). Results of exploratory and confirmatory factor analyses suggest that a 2-factor model from a shortened version of the scale (3 items were eliminated from each emotion scale), involving supportive and unsupportive socialization strategies, is a good alternative model to the original 5-factor structure for researchers interested in broader conceptualization of emotion socialization strategies. This 2-factor model of the shortened scale showed stronger measurement invariance across gender than racial/ethnic groups. Future studies addressing racial/ethnic differences with this measure should compare the results with and without imposing corresponding invariance constraints on noninvariant items. Findings of this study should be replicated in other age and racial/ethnic groups, and examine the predictive utility of the abbreviated 2-factor model for emotion-related outcomes across development. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  12. Factor Structure of Early Smoking Experiences and Associations with Smoking Behavior: Valence or Sensitivity Model?

    Directory of Open Access Journals (Sweden)

    Stéphanie Baggio

    2013-11-01

    Full Text Available The Early Smoking Experience (ESE questionnaire is the most widely used questionnaire to assess initial subjective experiences of cigarette smoking. However, its factor structure is not clearly defined and can be perceived from two main standpoints: valence, or positive and negative experiences, and sensitivity to nicotine. This article explores the ESE’s factor structure and determines which standpoint was more relevant. It compares two groups of young Swiss men (German- and French-speaking. We examined baseline data on 3,368 tobacco users from a representative sample in the ongoing Cohort Study on Substance Use Risk Factors (C-SURF. ESE, continued tobacco use, weekly smoking and nicotine dependence were assessed. Exploratory structural equation modeling (ESEM and structural equation modeling (SEM were performed. ESEM clearly distinguished positive experiences from negative experiences, but negative experiences were divided in experiences related to dizziness and experiences related to irritations. SEM underlined the reinforcing effects of positive experiences, but also of experiences related to dizziness on nicotine dependence and weekly smoking. The best ESE structure for predictive accuracy of experiences on smoking behavior was a compromise between the valence and sensitivity standpoints, which showed clinical relevance.

  13. Stable carbon and nitrogen isotope trophic enrichment factors for Steller sea lion vibrissae relative to milk and fish/invertebrate diets

    Science.gov (United States)

    Stricker, Craig A.; Christ, Aaron M.; Wunder, Michael B.; Doll, Andrew C.; Farley, Sean D.; Rea, Lorrie D.; Rosen, David A. S.; Scherer, R. D.; Tollit, Dominic J.

    2015-01-01

    Nutritional constraints have been proposed as a contributor to population declines in the endangered Steller sea lion Eumetopias jubatus in some regions of the North Pacific. Isotopic analysis of vibrissae (whiskers) is a potentially useful approach to resolving the nutritional ecology of this species because long-term (up to 8 yr) dietary information is sequentially recorded and metabolically inert once formed. Additionally, vibrissae are grown in utero, potentially offering indirect inference on maternal diet. However, diet reconstruction using isotopic techniques requires a priori knowledge of trophic enrichment factors (TEFs), which can vary relative to diet quality and among animal species. In this study, we provide new TEF estimates for (1) maternal relative to pup vibrissae during both gestation and nursing and (2) adult vibrissae relative to a complex diet. Further, we refine vibrissa-milk TEFs based on an additional 76 animals with an age distribution ranging from 1 to 20 mo. Mother-pup vibrissae TEF values during gestation and nursing were near zero for δ13C and averaged 0.8 and 1.6‰, respectively, for δ15N. In contrast, vibrissa-fish/invertebrate TEFs averaged 3.3 (± 0.3 SD) and 3.7‰ (±0.3) for lipid-free δ13C and δ15N, respectively. Average lipid-free δ13C and δ15N vibrissa-milk TEFs were 2.5 (±0.9) and 1.8‰ (±0.8), respectively, and did not differ among metapopulations. Empirically determined TEFs are critical for accurate retrospective diet modeling, particularly for evaluating the hypothesis of nutritional deficiency contributing to the lack of Steller sea lion population recovery in some regions of Alaska.

  14. Recovering hidden diagonal structures via non-negative matrix factorization with multiple constraints.

    Science.gov (United States)

    Yang, Xi; Han, Guoqiang; Cai, Hongmin; Song, Yan

    2017-03-31

    Revealing data with intrinsically diagonal block structures is particularly useful for analyzing groups of highly correlated variables. Earlier researches based on non-negative matrix factorization (NMF) have been shown to be effective in representing such data by decomposing the observed data into two factors, where one factor is considered to be the feature and the other the expansion loading from a linear algebra perspective. If the data are sampled from multiple independent subspaces, the loading factor would possess a diagonal structure under an ideal matrix decomposition. However, the standard NMF method and its variants have not been reported to exploit this type of data via direct estimation. To address this issue, a non-negative matrix factorization with multiple constraints model is proposed in this paper. The constraints include an sparsity norm on the feature matrix and a total variational norm on each column of the loading matrix. The proposed model is shown to be capable of efficiently recovering diagonal block structures hidden in observed samples. An efficient numerical algorithm using the alternating direction method of multipliers model is proposed for optimizing the new model. Compared with several benchmark models, the proposed method performs robustly and effectively for simulated and real biological data.

  15. Examining Factor Structure of the Chinese Version of the PIRLS 2011 Home Questionnaire

    Directory of Open Access Journals (Sweden)

    Wai Ming Cheung

    2016-01-01

    Full Text Available The home questionnaire of the Progress in International Reading Literacy Study (PIRLS-HQ 2011 was designed to gather information from parents or primary caregivers of fourth-grade pupils on their reading literacy development related to aspects of pupils’ home lives across countries/districts. The questionnaire was translated into different languages for international comparison and research purposes. This study aims to assess the psychometric properties of the Chinese version of the PIRLS 2011 home questionnaire (PIRLS-HQCV 2011 and identify the underlying factor structure using exploratory factor analysis (EFA and confirmatory factor analysis (CFA among Chinese fourth-grade pupils in Hong Kong. A 7-factor structure model has been identified by EFA and confirmed to resemble much to the original PIRLS structure by CFA. Additional conceptually important domains have been identified which add further insights into the inconclusive results in the literature regarding the relationship between home factors and reading achievement. Implications for further studies are discussed.

  16. Relating Education, Brain Structure, and Cognition: The Role of Cardiovascular Disease Risk Factors

    Directory of Open Access Journals (Sweden)

    Moyra E. Mortby

    2014-01-01

    Full Text Available The protective effect of education on cognitive and brain health is well established. While the direct effects of individual cardiovascular disease (CVD risk factors (i.e., hypertension, smoking, diabetes, and obesity on cerebral structure have been investigated, little is understood about the possible interaction between the protective effect of education and the deleterious effects of CVD risk factors in predicting brain ageing and cognition. Using data from the PATH Through Life study (N=266, we investigated the protective effect of education on cerebral structure and function and tested a possible mediating role of CVD risk factors. Higher education was associated with larger regional grey/white matter volumes in the prefrontal cortex in men only. The association between education and cognition was mediated by brain volumes but only for grey matter and only in relation to information processing speed. CVD risk factors did not mediate the association between regional volumes and cognition. This study provides additional evidence in support for a protective effect of education on cerebral structures and cognition. However, it does not provide support for a mediating role of CVD risk factors in these associations.

  17. The structure of the General Health Questionnaire (GHQ-12): two meta-analytic factor analyses.

    Science.gov (United States)

    Gnambs, Timo; Staufenbiel, Thomas

    2018-01-30

    The General Health Questionnaire (GHQ-12) is a popular measure of psychological distress. Despite its widespread use, an ongoing controversy pertains to its internal structure. Although the GHQ-12 was originally constructed to capture a unitary construct, empirical studies identified different factor structures. Therefore, this study examined the dimensionality of the GHQ-12 in two independent meta-analyses. The first meta-analysis used summary data published in 38 primary studies (total N = 76,473). Meta-analytic exploratory factor analyses identified two factors formed by negatively and positively worded items. The second meta-analysis included individual responses of 410,640 participants from 84 independent samples. Meta-analytic confirmatory factor analyses corroborated the two-dimensional structure of the GHQ-12. However, bifactor modelling showed that most of the variance was explained by a general factor. Therefore, subscale scores reflected rather limited unique variance. Overall, the two meta-analyses demonstrated that the GHQ-12 is essentially unidimensional. It is not recommended to use and interpret subscale scores because they primarily reflect general mental health rather than distinct constructs.

  18. Structural analysis of an eIF3 subcomplex reveals conserved interactions required for a stable and proper translation pre-initiation complex assembly

    Czech Academy of Sciences Publication Activity Database

    Herrmannová, Anna; Daujotyte, D.; Yang, J.; Ch.; Cuchalová, Lucie; Gorrec, F.; Wagner, Susan; Dányi, István; Lukavsky, P. J.; Valášek, Leoš Shivaya

    Roč. 40, č. 5 ( 2012 ), s. 2294-2311 ISSN 0305-1048 Institutional research plan: CEZ:AV0Z50200510 Keywords : START CODON SELECTION * RNA RECOGNITION MOTIF * GCN4 MESSENGER-RNA Subject RIV: CE - Biochemistry Impact factor: 8.278, year: 2012

  19. Structural factors that increase HIV/STI vulnerability among indigenous people in the Peruvian amazon.

    Science.gov (United States)

    Orellana, E Roberto; Alva, Isaac E; Cárcamo, Cesar P; García, Patricia J

    2013-09-01

    We examined structural factors-social, political, economic, and environmental-that increase vulnerability to HIV among indigenous people in the Peruvian Amazon. Indigenous adults belonging to 12 different ethnic groups were purposively recruited in four Amazonian river ports and 16 indigenous villages. Qualitative data revealed a complex set of structural factors that give rise to environments of risk where health is constantly challenged. Ferryboats that cross Amazonian rivers are settings where unprotected sex-including transactional sex between passengers and boat crew and commercial sex work-often take place. Population mobility and mixing also occurs in settings like the river docks, mining sites, and other resource extraction camps, where heavy drinking and unprotected sex work are common. Multilevel, combination prevention strategies that integrate empirically based interventions with indigenous knowledge are urgently needed, not only to reduce vulnerability to HIV transmission, but also to eliminate the structural determinants of indigenous people's health.

  20. X-Ray structure and biophysical properties of rabbit fibroblast growth factor 1

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jihun; Blaber, Sachiko I.; Irsigler, Andre; Aspinwall, Eric; Blaber, Michael; (FSU)

    2010-01-14

    The rabbit is an important and de facto animal model in the study of ischemic disease and angiogenic therapy. Additionally, fibroblast growth factor 1 (FGF-1) is emerging as one of the most important growth factors for novel pro-angiogenic and pro-arteriogenic therapy. However, despite its significance, the fundamental biophysical properties of rabbit FGF-1, including its X-ray structure, have never been reported. Here, the cloning, crystallization, X-ray structure and determination of the biophysical properties of rabbit FGF-1 are described. The X-ray structure shows that the amino-acid differences between human and rabbit FGF-1 are solvent-exposed and therefore potentially immunogenic, while the biophysical studies identify differences in thermostability and receptor-binding affinity that distinguish rabbit FGF-1 from human FGF-1.

  1. Factor structure of the Emotional Eating Scale in overweight and obese adults seeking treatment.

    Science.gov (United States)

    Goldbacher, E M; Grunwald, H E; Lagrotte, C A; Klotz, A A; Oliver, T L; Musliner, K L; Vanderveur, S S; Foster, G D

    2012-10-01

    The purpose of this study was to examine the factor structure and anthropometric correlates of the Emotional Eating Scale in overweight and obese adults presenting for weight loss. Participants were 217 men and women with a mean body-mass index of 33.1 (±3.4) kg/m². Results indicated a four factor structure: depression, anger, anxiety, and somatic arousal. These factors demonstrated strong internal consistency, and together accounted for approximately 60% of the total variance. Women had significantly higher depression and total scores than did men. There were no significant correlations between the Emotional Eating Scale scores and anthropometric measures. This work begins to add to the literature base regarding the applicability of the original design of the Emotional Eating Scale for samples consisting of men and African Americans. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Factor structure of the Emotional Eating Scale in overweight and obese adults seeking treatment ✩

    Science.gov (United States)

    Goldbacher, E.M.; Grunwald, H.E.; LaGrotte, C.A.; Klotz, A.A.; Oliver, T.L.; Musliner, K.L.; VanderVeur, S.S.; Foster, G.D.

    2012-01-01

    The purpose of this study was to examine the factor structure and anthropometric correlates of the Emotional Eating Scale in overweight and obese adults presenting for weight loss. Participants were 217 men and women with a mean body-mass index of 33.1 (±3.4) kg/m2. Results indicated a four factor structure: depression, anger, anxiety, and somatic arousal. These factors demonstrated strong internal consistency, and together accounted for approximately 60% of the total variance. Women had significantly higher depression and total scores than did men. There were no significant correlations between the Emotional Eating Scale scores and anthropometric measures. This work begins to add to the literature base regarding the applicability of the original design of the Emotional Eating Scale for samples consisting of men and African Americans. PMID:22510311

  3. Factor Analysis of an Expanded Halstead-Reitan Battery and the Structure of Neurocognition.

    Science.gov (United States)

    Patt, Virginie M; Brown, Gregory G; Thomas, Michael L; Roesch, Scott C; Taylor, Michael J; Heaton, Robert K

    2018-02-01

    The structure of neurocognition is explored by examining the neurocognitive domains underlying comprehensive neuropsychological assessment of cognitively healthy individuals. Exploratory factor analysis was conducted on the adult normative dataset of an expanded Halstead-Reitan Battery (eHRB), comprising Caucasian and African American participants. The factor structure contributions of the original HRB, eHRB expansion, and Wechsler intelligence scales were compared. Demographic effects were examined on composite factor scores calculated using confirmatory factor analysis. The full eHRB had an eight-factor structure, with latent constructs including: 'working memory', 'fluency', 'verbal episodic memory', 'visuospatial cognition' (visuospatial memory and problem solving), 'perceptual-motor speed' (speed for processing visual/tactile material and hand-motor execution), 'perceptual attention' (attention to sensory-perceptual information), 'semantic knowledge' (knowledge acquired through education and culturally-based experiences), and 'phonological decoding' (grapheme-phoneme processing essential for sounding-out words). 'Perceptual-motor speed' and 'perceptual attention' were most negatively associated with age, whereas 'semantic knowledge' and 'phonological decoding' were most resistant to aging. 'Semantic knowledge' showed the greatest dependence on demographic background, including education and ethnicity. Gender differences in cognitive performances were negligible across all domains except 'phonological decoding' with women slightly outperforming men. The original HRB contributed four neurocognitive domains, the eHRB expansion three domains, and the Wechsler scales one additional domain but with restructuring of verbal factors. Eight neurocognitive domains underlie performance of healthy cognitive individuals during comprehensive neuropsychological assessment. These domains serve as framework for understanding the constructs measured by commonly

  4. Variability in the combustion-derived fraction of urban humidity in Salt Lake City winter estimated from stable water vapor isotopes and its relationship to atmospheric stability and inversion structure

    Science.gov (United States)

    Fiorella, R.; Bares, R.; Lin, J. C.; Strong, C.; Bowen, G. J.

    2017-12-01

    Water released from the combustion of fossil fuels, while a negligible part of the global hydrological cycle, may be a significant contributor to urban humidity as fossil fuel emissions are strongly concentrated in space and time. The fraction of urban humidity comprised of combustion-derived vapor (CDV) cannot be observed through humidity measurements alone. However, the distinct stable isotopic composition of CDV, which arises from the reaction of 18O-enriched atmospheric O2 with 2H-depleted organic molecules, represents a promising method to apportion observed humidity between CDV and advected vapor. We apply stable water vapor isotopes to investigate variability in CDV amount and its relationship to atmospheric conditions in Salt Lake City, Utah. The Salt Lake Valley experiences several periods of atmospheric stratification during winter known as cold air pools, during which concentrations of CDV and pollutants can be markedly elevated due to reduced atmospheric mixing. Therefore, the SLV during winter is an ideal place to investigate variability in CDV fraction across a spectrum of boundary layer conditions, ranging from well-mixed to very stable. We present water vapor isotope data from four winters (2013-2017) from the top of a 30 m building on the University of Utah (U of U) Campus. Additionally, we present water vapor isotope data from the summit of Hidden Peak from the 2016-2017 winter, 25 km SE and 2000 m above the U of U site. The Hidden Peak site is consistently above the cold air pool emplaced in the SLV during stable events. We find the expression of the CDV signal in the valley is related to the atmospheric structure of the cold air pools in the SLV, and that the fraction of CDV inferred in the valley is likely related to the mixing height within the cold air pool. Furthermore, we find that patterns between the Hidden Peak and U of U sites during inversion events may record the large-scale atmospheric dynamics promoting emplacement of the cold air

  5. Factor structure and construct validity of the temporal experience of pleasure scales.

    Science.gov (United States)

    Ho, Paul M; Cooper, Andrew J; Hall, Phillip J; Smillie, Luke D

    2015-01-01

    Feelings of pleasure felt in the moment of goal attainment (consummatory pleasure) are thought to be dissociable from feelings of desire connected with the motivated approach of goals (anticipatory pleasure). The Temporal Experience of Pleasure Scales (TEPS; Gard, Gard, Kring, & John, 2006) was developed to assess individual differences in these distinct processes. Recently, an independent evaluation of the psychometric characteristics of a Chinese-translated TEPS suggested a more complex factor structure (Chan et al., 2012). This study aimed to reexamine the factor structure and convergent and divergent validity of the TEPS in two previously unexamined multiethnic samples. University students in the United Kingdom (N = 294) completed the TEPS and university students in Australia (N = 295) completed the TEPS as well as a battery of conceptually related questionnaires. A confirmatory factor analysis of Gard et al.'s (2006) 2-factor model produced inadequate fit, which model-modification indexes suggested might be due to item cross-loadings. This issue was examined further using an exploratory factor analysis, which revealed a clear 2-factor solution despite cross-loadings among some items. Finally, mixed evidence for convergent-divergent validity was obtained, in terms of relationships between the TEPS and measures of anhedonia, approach-motivation, and positive emotion.

  6. Reliability, Validity and Factor Structure of the 12-Item General Health Questionnaire among General Population

    Science.gov (United States)

    Petkovska, Miodraga Stefanovska; Bojadziev, Marjan I.; Stefanovska, Vesna Velikj

    2015-01-01

    AIM: The aim of the study is to analyze the internal consistency; validity and factor structure of the twelve item General Health Questionnaire for the Macedonian general population. MATERIAL AND METHODS: Data came from nationally representative sample of 1603 randomly selected Macedonians all aged 18 years or older. RESULTS: The mean GHQ score in the general sample was found to be 7.9 (SD = 4.3). The results revealed a higher GHQ score among women (M = 8.91, SD = 4.5) compared to men (M = 6.89; SD = 4.2). The participants from the rural areas obtained a lower GHQ score (M = 7.55, SD = 3.8) compared to participants coming from the urban areas (M = 9.37, SD = 4.1). The principal component analysis with oblique rotation (direct oblimin) with maximum likelihood procedure solution was performed and the results yielded a three factor solution which jointly accounted for 57.17% of the total variance: Factor I named social management (items 1, 3, 4, 6, 7 and 8); Factor II stress (items 2, 5 and 9) and Factor III named self-confidence (items 10, 11 and 12). Its factor structure is in line with representative research from other population groups. CONCLUSION: The GHQ-12 can be used effectively for assessment of the overall psychological well-being and detection of non-psychotic psychiatric problems among the Macedonian population. PMID:27275274

  7. Hardware-Based Non-Optimum Factors for Launch Vehicle Structural Design

    Science.gov (United States)

    Wu, K. Chauncey; Cerro, Jeffrey A.

    2010-01-01

    During aerospace vehicle conceptual and preliminary design, empirical non-optimum factors are typically applied to predicted structural component weights to account for undefined manufacturing and design details. Non-optimum factors are developed here for 32 aluminum-lithium 2195 orthogrid panels comprising the liquid hydrogen tank barrel of the Space Shuttle External Tank using measured panel weights and manufacturing drawings. Minimum values for skin thickness, axial and circumferential blade stiffener thickness and spacing, and overall panel thickness are used to estimate individual panel weights. Panel non-optimum factors computed using a coarse weights model range from 1.21 to 1.77, and a refined weights model (including weld lands and skin and stiffener transition details) yields non-optimum factors of between 1.02 and 1.54. Acreage panels have an average 1.24 non-optimum factor using the coarse model, and 1.03 with the refined version. The observed consistency of these acreage non-optimum factors suggests that relatively simple models can be used to accurately predict large structural component weights for future launch vehicles.

  8. The factor structure of the CES-D in a sample of Rwandan genocide survivors.

    Science.gov (United States)

    Lacasse, Justin J; Forgeard, Marie J C; Jayawickreme, Nuwan; Jayawickreme, Eranda

    2014-03-01

    Past research suggests that culture shapes the way psychopathology is experienced and expressed. Standard psychiatric assessment instruments may therefore not capture the same underlying constructs in different contexts. The present study investigated the factor structure of a standard depression scale in a sample of Rwandan genocide survivors. One hundred ninety six Rwandan adults provided socio-demographic information and completed the Center for Epidemiological Studies-Depression scale (CES-D), one of the most widely used self-report instruments assessing depressive symptoms, as part of a larger study on well-being and mental health in Rwanda. A two-factor solution provided the best fit for these CES-D data. The first factor corresponded to general depressive symptoms (including depressed affect, somatic symptoms, and interpersonal concerns) and explained 37.20% of the variance. The second factor included items assessing positive affect and explained 8.68% of the variance. The two-factor solution found in the present study deviates from the commonly reported four-factor structure, but is consistent with studies showing that depressed affect and somatic symptoms may not be experienced as distinct in certain non-Western and minority cultural groups.

  9. Factor structure of the Communicator Styles Measure (CSM) when used with undergraduate health science students.

    Science.gov (United States)

    Brown, Ted; Boyle, Malcolm; Williams, Brett; Molloy, Andrew; McKenna, Lisa; Palermo, Claire; Molloy, Liz

    2013-06-01

    It is important for educators to consider the communication skills of students enrolled in health science programmes. To date, research into this area is limited, and having measures that are valid and reliable would assist educators and researchers to complete high-quality investigations. The purpose of this study was to investigate the factor structure of Communicator Styles Measure. Data from the Communicator Styles Measure completed by 860 undergraduate health science students enrolled in eight different courses at an Australian university (response rate of 59%) were analysed using principal component analysis with varimax rotation and a cluster analysis using elementary linkage analysis. The Communicator Styles Measure is a self-report scale consisting of 40 items designed to assess ten communication styles and one's perception of his/her ability to communicate. Communicator Styles Measure items loaded onto five new viable factors labelled personable, energetic, confident, open and confronting. Six items of the original 40 from the Communicator Styles Measure did not load onto any factor and were therefore considered redundant. The original factor structure proposed by the Communicator Styles Measure's author was not supported, which calls into question its construct validity. However, the five new factors identified in this study may be useful for researchers and educators when assessing the communication skills of students and practitioners. Further investigation into the construct validity and reliability of the five new Communicator Styles Measure factors is recommended. © 2012 Nordic College of Caring Science.

  10. The influence of nitrogen inputs on biomass and trophic structure of ocean plankton: a study using biomass and stable isotope size-spectra

    KAUST Repository

    Mompeán, Carmen

    2016-08-18

    Large scale patterns in planktonic food web structure were studied by applying continuous size-scaled models of biomass and δ15N to plankton samples, collected at 145 stations during the Malaspina-2010 Expedition across three ocean basins and including major biomes. Carbon biomass and δ15N were determined in size-fractionated samples (40 to 5000 μm) collected by vertical hauls (0–200 m). Biomass-normalized size-spectra were constructed to summarize food web structure and spatial patterns in spectral parameters were analyzed using geographically-weighted regression analysis. Except in the northwestern Atlantic, size-spectra showed low variability, reflecting a homogeneity in nitrogen sources and food web structure for the central oceans. Estimated predator-to-prey mass ratios <104 and mean trophic transfer efficiency values between 16% (coastal biome) and >20% (Trades and Westerlies biomes) suggested that oceanic plankton food webs may support a larger number of trophic levels than current estimates based on high efficiency values. The largest changes in spectral parameters and nitrogen sources were related to inputs of atmospheric nitrogen, either from diazotrophic organisms or dust deposition. These results suggest geographic homogeneity in the net transfer of nitrogen up the food web.

  11. A preliminary factor analytic investigation into the firstorder factor structure of the Fifteen Factor Plus (15FQ+ on a sample of Black South African managers

    Directory of Open Access Journals (Sweden)

    Seretse Moyo

    2011-10-01

    Research purpose: The primary objective of this study was to undertake a factor analytic investigation of the first-order factor structure of the 15FQ+. Motivation for the study: The construct validity of the 15FQ+, as a measure of personality, is necessary even though it is insufficient to justify its use in personnel selection. Research design, approach and method: The researchers evaluated the fit of the measurement model, which the structure and scoring key of the 15FQ+ implies, in a quantitative study that used an ex post facto correlation design through structural equation modelling. They conducted a secondary data analysis. They selected a sample of 241 Black South African managers from a large 15FQ+ database. Main findings: The researchers found good measurement model fit. The measurement model parameter estimates were worrying. The magnitude of the estimated model parameters suggests that the items generally do not reflect the latent personality dimensions the designers intended them to with a great degree of precision. The items are reasonably noisy measures of the latent variables they represent. Practical/managerial implications: Organisations should use the 15FQ+ carefully on Black South African managers until further local research evidence becomes available. Contribution/value-add: The study is a catalyst to trigger the necessary additional research we need to establish convincingly the psychometric credentials of the 15FQ+ as a valuable assessment tool in South Africa.

  12. Ab initio prediction of stable nanotwin double layers and 4O structure in Ni.sub.2./sub.MnGa

    Czech Academy of Sciences Publication Activity Database

    Zelený, M.; Straka, Ladislav; Sozinov, A.; Heczko, Oleg

    2016-01-01

    Roč. 94, č. 22 (2016), s. 1-6, č. článku 224108. ISSN 2469-9950 R&D Projects: GA ČR GA16-00043S Institutional support: RVO:68378271 Keywords : ab initio * magnetic shape memory * martensite * modulation * Ni-Mn-Ga Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.836, year: 2016

  13. Stable hydrogen and oxygen isotopes of tap water reveal structure of the San Francisco Bay Area's water system and adjustments during a major drought.

    Science.gov (United States)

    Tipple, Brett J; Jameel, Yusuf; Chau, Thuan H; Mancuso, Christy J; Bowen, Gabriel J; Dufour, Alexis; Chesson, Lesley A; Ehleringer, James R

    2017-08-01

    Water availability and sustainability in the Western United States is a major flashpoint among expanding communities, growing industries, and productive agricultural lands. This issue came to a head in 2015 in the State of California, when the State mandated a 25% reduction in urban water use following a multi-year drought that significantly depleted water resources. Water demands and challenges in supplying water are only expected to intensify as climate perturbations, such as the 2012-2015 California Drought, become more common. As a consequence, there is an increased need to understand linkages between urban centers, water transport and usage, and the impacts of climate change on water resources. To assess if stable hydrogen and oxygen isotope ratios could increase the understanding of these relationships within a megalopolis in the Western United States, we collected and analyzed 723 tap waters across the San Francisco Bay Area during seven collection campaigns spanning 21 months during 2013-2015. The San Francisco Bay Area was selected as it has well-characterized water management strategies and the 2012-2105 California Drought dramatically affected its water resources. Consistent with known water management strategies and previously collected isotope data, we found large spatiotemporal variations in the δ 2 H and δ 18 O values of tap waters within the Bay Area. This is indicative of complex water transport systems and varying municipality-scale management decisions. We observed δ 2 H and δ 18 O values of tap water consistent with waters originating from snowmelt from the Sierra Nevada Mountains, local precipitation, ground water, and partially evaporated reservoir sources. A cluster analysis of the isotope data collected in this study grouped waters from 43 static sampling sites that were associated with specific water utility providers within the San Francisco Bay Area and known management practices. Various management responses to the drought, such as

  14. Factor structure of the Japanese version of the Edinburgh Postnatal Depression Scale in the postpartum period.

    Science.gov (United States)

    Kubota, Chika; Okada, Takashi; Aleksic, Branko; Nakamura, Yukako; Kunimoto, Shohko; Morikawa, Mako; Shiino, Tomoko; Tamaji, Ai; Ohoka, Harue; Banno, Naomi; Morita, Tokiko; Murase, Satomi; Goto, Setsuko; Kanai, Atsuko; Masuda, Tomoko; Ando, Masahiko; Ozaki, Norio

    2014-01-01

    The Edinburgh Postnatal Depression Scale (EPDS) is a widely used screening tool for postpartum depression (PPD). Although the reliability and validity of EPDS in Japanese has been confirmed and the prevalence of PPD is found to be about the same as Western countries, the factor structure of the Japanese version of EPDS has not been elucidated yet. 690 Japanese mothers completed all items of the EPDS at 1 month postpartum. We divided them randomly into two sample sets. The first sample set (n = 345) was used for exploratory factor analysis, and the second sample set was used (n = 345) for confirmatory factor analysis. The result of exploratory factor analysis indicated a three-factor model consisting of anxiety, depression and anhedonia. The results of confirmatory factor analysis suggested that the anxiety and anhedonia factors existed for EPDS in a sample of Japanese women at 1 month postpartum. The depression factor varies by the models of acceptable fit. We examined EPDS scores. As a result, "anxiety" and "anhedonia" exist for EPDS among postpartum women in Japan as already reported in Western countries. Cross-cultural research is needed for future research.

  15. Factor structure of the Japanese version of the Edinburgh Postnatal Depression Scale in the postpartum period.

    Directory of Open Access Journals (Sweden)

    Chika Kubota

    Full Text Available BACKGROUND: The Edinburgh Postnatal Depression Scale (EPDS is a widely used screening tool for postpartum depression (PPD. Although the reliability and validity of EPDS in Japanese has been confirmed and the prevalence of PPD is found to be about the same as Western countries, the factor structure of the Japanese version of EPDS has not been elucidated yet. METHODS: 690 Japanese mothers completed all items of the EPDS at 1 month postpartum. We divided them randomly into two sample sets. The first sample set (n = 345 was used for exploratory factor analysis, and the second sample set was used (n = 345 for confirmatory factor analysis. RESULTS: The result of exploratory factor analysis indicated a three-factor model consisting of anxiety, depression and anhedonia. The results of confirmatory factor analysis suggested that the anxiety and anhedonia factors existed for EPDS in a sample of Japanese women at 1 month postpartum. The depression factor varies by the models of acceptable fit. CONCLUSIONS: We examined EPDS scores. As a result, "anxiety" and "anhedonia" exist for EPDS among postpartum women in Japan as already reported in Western countries. Cross-cultural research is needed for future research.

  16. Toward the Rational Design of Novel Noncentrosymmetric Materials: Factors Influencing the Framework Structures.

    Science.gov (United States)

    Ok, Kang Min

    2016-12-20

    Solid-state materials with extended structures have revealed many interesting structure-related characteristics. Among many, materials crystallizing in noncentrosymmetric (NCS) space groups have attracted massive attention attributable to a variety of superb functional properties such as ferroelectricity, pyroelectricity, piezoelectricity, and nonlinear optical (NLO) properties. In fact, the characteristics are pivotal to many industrial applications such as laser systems, optical communications, photolithography, energy harvesting, detectors, and memories. Thus, for the past several decades, a great deal of synthetic effort has been vigorously made to realize these technologically important properties by improving the occurrence of macroscopic NCS space groups. A bright approach to increase the incidence of NCS structures was combining local asymmetric units during the initial synthesis process. Although a significant improvement has been achieved in obtaining new NCS materials using this strategy, the majority of solid-state materials still crystallize in centrosymmetric (CS) structures as the locally unsymmetrical units are easily lined up in an antiparallel manner. Therefore, discovering an effective method to control the framework structure and the macroscopic symmetry is an imminent ongoing challenge. In order to more effectively control the overall symmetry of solid-state compounds, it is critical to understand how the backbone and the subsequent centricity are affected during the crystallization. In this Account, several factors influencing the framework structure and centricity of solid-state materials are described in order to more systematically discover novel NCS materials. Recent studies on crystalline solid-state materials suggest three factors affecting the local coordination environment as well as the overall symmetry of the framework structure: (1) size variations of the various template cations, (2) a variable backbone arrangement occurring from

  17. Syntheses, structures and photoelectrochemical properties of three water-stable, visible light absorbing mental-organic frameworks based on tetrakis(4-carboxyphenyl)silane and 1,4-bis(pyridyl)benzene mixed ligands

    Science.gov (United States)

    Guo, Tiantian; Yang, Xiaowei; Li, Ruyan; Liu, Xiaoyu; Gao, Yanling; Dai, Zhihui; Fang, Min; Liu, Hong-Ke; Wu, Yong

    2017-09-01

    Photovoltaics (PV), which directly convert solar energy into electricity generally using semiconductors, offer a practical and sustainable solution to the current energy shortage and environmental pollution crisis. Photovoltaic applications of metal-organic frameworks (MOFs) belong to a relatively new area of research. Given that UV light accounts for only 4% while visible light contributes 43% of solar energy, it is rather imperative to develop semiconductors with narrow band gaps so that they could absorb visible light. In this work, three water-stable, narrow band semiconducting MOFs of [Cu(H2TCS)(H2O)] (1), [Co(H2TCS)(BPB)] (2) and [Ni(H2TCS)(BPB)] (3) were synthesized using tetrakis(4-carboxyphenyl)silane (H4TCS) and 1,4-bis (pyridyl)benzene (BPB) in water, and structurally characterized by single-crystal X-ray diffractions. MOF 1 has a 2D structure. MOF 2 and 3 are isostructrual and have 3D frameworks formed by interwoven 2D layers. All three MOFs are stable in acidic water solutions and can be stable in water for 7 days. MOFs 1-3 absorb UV and visible light and have band gaps of 0.50, 1.77 and 1.49 eV, respectively. Rapid and stable photocurrent responses of MOFs 1-3 under UV and visible light illuminations are observed. This work demonstrates that using electron rich Cu2+, Co2+, or Ni2+ as metal nodes can effectively decrease the band gaps of MOFs to make them absorbing visible light. To increase the conjugation in the linker is generally considered to be the method to decrease the band gap of MOFs. The conjugation in H4TCS is not significant and this ligand basically only absorbs UV light. However, by using electron rich Cu2+ ions as metal nodes, the prepared [Cu(H2TCS)(H2O)]·H2O (1) absorbs broadly in the visible light region. Thus, this work suggests that by using electron rich Cu2+, many narrow-band semiconductor MOFs can be prepared even by using ligands which only absorbs UV light.

  18. Identification and Structural Basis of Binding to Host Lung Glycogen by Streptococcal Virulence Factors

    Energy Technology Data Exchange (ETDEWEB)

    Lammerts van Bueren,A.; Higgins, M.; Wang, D.; Burke, R.; Boraston, A.

    2007-01-01

    The ability of pathogenic bacteria to recognize host glycans is often essential to their virulence. Here we report structure-function studies of previously uncharacterized glycogen-binding modules in the surface-anchored pullulanases from Streptococcus pneumoniae (SpuA) and Streptococcus pyogenes (PulA). Multivalent binding to glycogen leads to a strong interaction with alveolar type II cells in mouse lung tissue. X-ray crystal structures of the binding modules reveal a novel fusion of tandem modules into single, bivalent functional domains. In addition to indicating a structural basis for multivalent attachment, the structure of the SpuA modules in complex with carbohydrate provides insight into the molecular basis for glycogen specificity. This report provides the first evidence that intracellular lung glycogen may be a novel target of pathogenic streptococci and thus provides a rationale for the identification of the streptococcal {alpha}-glucan-metabolizing machinery as virulence factors.

  19. The effective factors on the structure of butter and other milk fat-based products

    DEFF Research Database (Denmark)

    Rønholt, Stine; Mortensen, Kell; Knudsen, Jes Christian

    2013-01-01

    Butter and other milk fat-based products are valuable products for the dairy industry due to their unique taste, their textural characteristics, and nutritional value. However, an increased consumer demand for low-fat-based products increases the need for an increased essential understanding...... of the effective factors governing the structure of milk fat-based products. Today, 2 manufacturing techniques are available: the churning method and the emulsification method. The first is typically used for production of butter with a globular structure, which has become increasingly popular to obtain low......-fat-based products, typically without presence of milk fat globules. The microstructure of milk fatbased products is strongly related to their structural rheology, hence applications. Structural behavior is not determined by one single parameter, but by the interactions between many. This complexity is reviewed here...

  20. Factors controlling strength of structures, and anticipated overstrength for seismic load conditions

    International Nuclear Information System (INIS)

    Singh, A.K.

    1985-01-01

    This paper discusses how the safe shutdown earthquake level, the ratio of operating basis earthquake to safe shutdown earthquake level, the shape of the earthquake spectra and the modeling of the structure affect the seismic overstrength of structures. The relationship between actual mean strength and the minimum specified strength of concrete and structural steel is also presented. The paper identifies which concrete and steel structures are generally sized for earthquake loads and which are generally sized for other factors, e.g., tornado missiles, loss of coolant accident pressure loads, equipment laydown loads and radiation shielding. The results of a study evaluating the mean ultimate capacity of a pressurized water reactor containment are presented to show that in terms of a ground motion, the seismic capacity may be four to five times the design safe shutdown earthquake level